TWI725550B - Expanded particles and expanded molded article - Google Patents

Abstract

The present invention relates to expanded particles and an expanded molded article. More specifically, the present invention relates to an expanded particle which uses a polycarbonate resin as the matrix resin and has a specific cell density X and an average cell wall thickness, and an expanded molded article. Further, the present invention relates to an expanded particle which uses a polycarbonate resin as the matrix resin and has a specific volume multiple and an average cell diameter, and an expanded molded article.

Description

Expanded particles and foamed molded products

The present invention relates to an expanded particle and an expanded molded body. More specifically, the present invention relates to a foamed molded product that uses polycarbonate resin as a base resin, has good appearance and high mechanical strength, and suppresses the change of mechanical strength from low temperature to high temperature. And the expanded particles capable of producing the expanded molded article with good moldability.

This case is based on Japanese Special Application No. 2018-185200 filed on September 28, 2018, Japanese Special Application No. 2019-058518 filed on March 26, 2019, and Japan filed on March 28, 2019 Special Application No. 2019-064060, Japanese Special Application No. 2019-067036 filed on March 29, 2019, and Japanese Special Application No. 2019-141409 filed on July 31, 2019, claim priority, and will The contents of these applications are quoted here.

Since the foam molding system is lighter, has good processability and shape retention, and high strength, it is used in a variety of building materials such as food trays and automotive components, civil engineering materials, and lighting fixtures. field. Especially in the case where heat resistance is not required, it is possible to use a foamed molded body made of polystyrene resin; and in terms of cushioning properties, recovery properties, and flexibility When properties are necessary, there is a tendency to use foamed molded articles made of olefin-based resins such as polypropylene and polyethylene.

Generally, as resins having higher heat resistance than these polystyrene-based resins and olefin-based resins, there are polycarbonate-based resins. This polycarbonate-based resin is a resin material that can be used even in harsh climates such as dry areas and tropical areas. This polycarbonate resin is not only excellent in heat resistance, but also excellent in water resistance, electrical properties, mechanical strength, aging resistance, and chemical resistance. Therefore, in the past, polycarbonate-based resins have been used as interior materials for buildings. However, in recent years, the expansion of applications such as automotive components, packaging materials, and various containers using its excellent properties has also been expected.

In this regard, the method for producing a foamed molded article of a polycarbonate resin is, for example, an in-mold foam molding method in which expanded particles are foamed and fused in a mold. This method prepares a mold with a space corresponding to the desired shape, fills the space with expanded particles, and expands and fuses the expanded particles by heating, thereby obtaining a complex shape of expanded molding body. However, this method has a problem that the appearance of the foamed molded product is not good and the fusion of the foamed particles is insufficient.

Therefore, the applicant of the present application proposed a technique for providing a foamed molded article with a good appearance by enhancing the mutual fusion of foamed particles (see Patent Document 1).

In addition, as the foamed molded product using the in-mold foam molding method, those using polystyrene resin as the base resin (for example, refer to Patent Document 2) and those using polyolefin resin as the base resin (for example, Refer to Patent Document 3).

[Prior technical literature] [Patent Literature]

[Patent Document 1] JP 2016-188321 A

[Patent Document 2] Japanese Patent Application Publication No. 2018-100380

[Patent Document 3] Japanese Patent Laid-Open No. 11-349724

In Patent Document 1, although a foamed molded product with a good appearance can be obtained, it is desired to provide a foamed molded product with a better appearance and higher mechanical strength by further improving the mutual fusion of the expanded particles. body.

In addition, the foamed molded product using polystyrene-based resin and polyolefin-based resin as the base resin has good mechanical strength near normal temperature (about 23°C), but it may be affected in a relatively low temperature and high temperature environment, although it has good mechanical strength near normal temperature (about 23°C). A situation where the mechanical strength is reduced. Therefore, it is desired to provide a foamed molded product that can suppress changes in mechanical strength even when the ambient temperature is changed.

In view of the above-mentioned problems, the inventors of the present invention conducted studies on the polycarbonate resin used. As a result, it was unexpectedly discovered that by setting the cell density X and the average cell wall thickness of the expanded particles in a specific range, it is possible to make The appearance and mechanical strength of the foamed molded article obtained from the expanded particles become good, and at the same time, the mutual fusion of the expanded particles can be improved, thus completing the present invention.

Therefore, according to the present invention, it is possible to provide expanded particles (hereinafter referred to as "first expanded particles") which are based on polycarbonate resins, wherein:

The aforementioned expanded particles have:

(i) The bubble density X of ^{1.0×10 6} cells/cm ³ or more and less than 1.0×10 ⁸ cells/cm ³

[The bubble density X is calculated according to the following formula:

Bubble density X=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ }

(In the formula, C means the average bubble diameter (μm), ρ means the density of the polycarbonate resin (kg/m ³ ), and D means the apparent density of the expanded particles (kg/m ³ ) )],and

(ii) The average bubble wall thickness of 1 to 15 μm.

In addition, the inventors of the present invention also unexpectedly discovered that by setting the bulk multiple and the average bubble diameter of the expanded particles in a specific range, the appearance of the foamed molded article obtained from the expanded particles can be improved. And the mechanical strength becomes good, and at the same time the mutual fusion of the expanded particles can be improved.

Therefore, according to the present invention, it is possible to provide expanded particles (hereinafter referred to as "second expanded particles"), the expanded particles using polycarbonate resin as the base resin, wherein:

The aforementioned expanded particles have a value in the range of 2.5 to 12 μm/time when the average bubble diameter of the aforementioned expanded particles is divided by the volume multiple of the aforementioned expanded particles.

Furthermore, according to the present invention, it is possible to provide a foamed molded product obtained from the above-mentioned foamed particles.

In addition, it is possible to provide a foamed molded article, the foamed molding system being obtained from a plurality of expanded particles using a polycarbonate resin as a base resin, wherein:

In the aforementioned foam molding system, the maximum point stress of the 4-point bending test was measured at each temperature of -40°C, 23°C, 80°C, and 140°C, and the maximum point stress of the bending test of the aforementioned 4-point value was calculated. When the average value is the value of the maximum point stress in the 4-point bending test, the rate of change relative to the average value is in the range of 0 to 50%.

According to the present invention, it is possible to provide expanded particles of a polycarbonate resin. The expanded particles of the polycarbonate resin use a polycarbonate resin as a base resin, and can be manufactured with good appearance and mechanical strength and fusion. Foam moldings with improved properties, and foam moldings that can be manufactured with good moldability.

In addition, it is possible to provide expanded particles of polycarbonate resin, which can be manufactured using polycarbonate resin as a base resin in any of the following cases. The appearance and mechanical strength of the resin are good, and the fusion property is good. Further improved foamed moldings, and expanded particles of polycarbonate resins that can produce foamed moldings with better moldability;

(1) The expanded particle system has an apparent density of ^{20 to 640 kg/m 3.}

(2) The average cell diameter is 20 to 200 μm, and the density of the polycarbonate-based resin is 1.0×10 ³ to 1.4×10 ³ kg/m ³ .

(3) The expanded particles have a cell number density of ^{1.0×10 7} to 1.0×10 ⁹ cells/cm ^3.

(4) The expanded particle system has a volume multiple of 2 to 20 times.

(5) Expanded particles have an open cell ratio of 0 to 10%.

Furthermore, according to the present invention, it is possible to provide a foamed molded article in which the foamed molding system can suppress changes in mechanical strength even if the ambient temperature changes.

In addition, it is possible to provide a foamed molded body that can further suppress the change in mechanical strength even if the ambient temperature changes in any of the following cases;

(1) The foam molding system has an open cell ratio of 0 to 50%.

(2) The foaming molding system has an expansion ratio of 3 to 30 times.

(3) In the foam molding system, the 4 points of the maximum point stress of the bending test are divided by the density of each foamed molded article to calculate the 4 points of the "maximum point stress/density of the bending test" and the 4 points When the average value of the "maximum point stress/density of the bending test" is the average value, the value of the 4-point "maximum point stress/density of the bending test" is within the range of 0 to 50% from the aforementioned average value.

(4) The polycarbonate resin system exhibits an MFR of 1.0 to 15.0 g/10 minutes.

(5) With respect to the "maximum point stress in the bending test" at 23°C, the "maximum point stress in the bending test" at -40°C varies from 0 to 0.88.

Fig. 1 is a photograph of the cross section of the expanded particles and molded foams of Examples 1a to 3a.

Figure 2 is a photograph of the cross section of the expanded particles and the expanded molded body of Examples 4a to 6a.

Fig. 3 is a photograph of the cross section of the expanded particles and the expanded molded body of Comparative Examples 1a to 3a.

Fig. 4 is a photograph of the cross section of the expanded particles and molded foams of Examples 1b to 6b.

Fig. 5 is a photograph of the cross section of the expanded beads and molded foams of Examples 7b to 9b.

Fig. 6 is a photograph of the cross section of the expanded particles and the expanded molded body of Comparative Examples 1b to 3b.

1. Expanded particles

The expanded particle system of the present invention contains the first expanded particle and the second expanded particle. In this specification, the above-mentioned first expanded particles and second expanded particles may be simply referred to as "expanded particles".

First, the first expanded particle of the present invention uses a polycarbonate resin as a base resin, and has a specific cell density X and an average cell wall thickness. The inventors of the present invention found that by adjusting the cell density X and the average cell wall thickness, the appearance and mechanical strength of the foamed molded product can be improved, and At this time, the mutual fusion of the expanded particles can be further improved.

In addition, the second expanded particle of the present invention uses a polycarbonate resin as a base resin, and has a specific volume multiple and an average cell diameter. The inventors of the present invention found that by adjusting the volume ratio and the average bubble diameter, the appearance and mechanical strength of the foamed molded product can be improved, and at the same time, the mutual fusion of the foamed particles can be further improved.

1-1. Bubble density X

The cell density X can be set to 1.0×10 ⁶ cells/cm ³ or more and less than 1.0×10 ⁸ cells/cm ³ . When the cell density X is less than 1.0×10 ⁶ cells/cm ³ , it may become difficult to increase the magnification. When the cell density X is 1.0×10 ⁸ cells/cm ³ or more, the cell wall thickness may decrease and the moldability may deteriorate. The preferred cell density X is 2.0×10 ⁶ cells/cm ³ or more and less than 1.0×10 ⁸ cells/cm ³ , and the more preferable cell density X is 5.0×10 ⁶ cells/cm ³ to 8.0×10 ⁷ cells/cm ³ .

Here, the bubble density X system can be calculated according to the following formula:

Bubble density X=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ }. In the formula, C means the average cell diameter (mm), ρ means the density of the polycarbonate resin (kg/m ³ ), and D means the apparent density of the expanded particles (kg/m ³ ).

The average bubble diameter C is preferably in the range of 20 to 200 μm. More preferably, the average bubble diameter C is 40 to 180 μm, and even more preferably, the average bubble diameter C is 50 to 150 μm.

The density ρ of the polycarbonate resin is preferably in the range of ^{1.0×10 3} to 1.4×10 ³ kg/m ^3. When the density is less than 1.0×10 ³ kg/m ³ , the heat-resistant temperature may decrease. When the density ρ is greater than 1.4×10 ³ kg/m ³ , the heat-resistant temperature may rise and foam molding may become difficult. A more preferable density ρ is 1.10×10 ³ to 1.35×10 ³ kg/m ³ , and a more preferable density ρ is 1.15×10 ³ to 1.30×10 ³ kg/m ³ .

The apparent density D of the expanded particles is preferably in the range of ^{20 to 640 kg/m 3.} When the apparent density D is less than 20 kg/m ³ , the bubble film may collapse during molding due to the thinning of the bubble film, the ratio of continuous bubbles may increase, and the buckling of the bubbles may cause the expanded particles to shrink. When the apparent density D is greater than 640 kg/m ³ , the bubble film may become thicker and the moldability may decrease. A more preferable apparent density D is 40 to 400 kg/m ³ , and a more preferable apparent density D is 50 to 200 kg/m ³ .

In addition, the bulk density of the expanded particles is preferably in the range of ^{12 to 600 kg/m 3.} When the bulk density is less than 12kg/m ³ , the bubble film may become thin and the bubble film may collapse during molding, the ratio of continuous bubbles will increase, and the buckling of the bubbles will cause the expanded beads to shrink. When the bulk density is greater than 600 kg/m ³ , the bubble film may become thicker and the moldability may decrease. More preferably a bulk density of 24 to 240kg / m ^3, and more preferably the bulk density of 30 to 120kg / m ^3.

1-2. Average bubble wall thickness

The average bubble wall thickness can be set to 1 to 15 μm. If the average cell wall thickness is less than 1 μm, the moldability during molding may deteriorate, especially the fusion may deteriorate. When the average cell wall thickness is greater than 15 μm, it may become difficult to increase the magnification. The preferred average cell wall thickness is 1 to 10 μm, and the more preferred average cell wall thickness is 1 to 5 μm.

1-3. The average bubble diameter of the expanded particles divided by the volume multiple of the expanded particles

The value obtained by dividing the average bubble diameter of the expanded particles by the volume multiple of the expanded particles shows a value in the range of 2.5 to 12 μm/time. If the value is less than 2.5 μm/time, the bubble film may collapse during molding due to the thinning of the bubble film, the ratio of continuous bubbles will increase, and the buckling of the bubbles will cause the expanded particles to shrink. When the value is more than 12 μm/time, the bubble film may become thicker and the moldability may decrease. The value is preferably 3.0 to 10.0 μm/time, more preferably 3.0 to 6.5 μm/time.

The volume multiple is preferably in the range of 2 to 20 times. When the volume ratio is less than 2 times, the bubble film may become thicker and the moldability may decrease. When the volume ratio is greater than 20 times, the bubble film may collapse due to the thinning of the bubble film, the ratio of continuous bubbles will increase, and the buckling of the bubbles will cause the expanded particles to shrink. The volume ratio is preferably 3 to 18 times, and even more preferably 5 to 16 times.

The average bubble diameter is preferably in the range of 20 to 200 μm. When the average bubble diameter is less than 20 μm, the bubble film may collapse during molding due to the thinning of the bubble film, the ratio of continuous bubbles will increase, and the buckling of the bubbles will cause the expanded particles to shrink. When the average bubble diameter is greater than 200 μm, the bubble film may become thicker and the moldability may decrease. The average bubble diameter is more preferably 20 to 150 μm, and more preferably 30 to 120 μm.

1-4. Bubble number density

The number density of bubbles is preferably 1.0×10 ⁷ to 1.0×10 ⁹ cells/cm ³ . When the number density of bubbles is less than 1.0×10 ⁷ cells/cm ³ , it may become difficult to increase the magnification. When the cell number density is 1.0×10 ⁹ cells/cm ³ or more, the cell wall thickness may decrease and the moldability may deteriorate. The number density of bubbles is preferably 3.0×10 ⁷ to 5.0×10 ⁸ cells/cm ³ .

Here, the bubble number density can be calculated according to the following formula:

Bubble number density=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ }. In the formula, C means the average cell diameter (mm), ρ means the density of the polycarbonate resin (kg/m ³ ), and D means the apparent density of the expanded particles (kg/m ³ ).

The average bubble diameter C is preferably in the above-mentioned range of 20 to 200 μm.

The density ρ of the polycarbonate resin is preferably in the range of ^{1.0×10 3} to 1.4×10 ³ kg/m ^3. When the density ρ is less than 1.0×10 ³ kg/m ³ , the heat-resistant temperature may decrease. When the density ρ is greater than 1.4×10 ³ kg/m ³ , the heat-resistant temperature may rise and foam molding may become difficult. The density ρ is preferably 1.10×10 ³ to 1.35×10 ³ kg/m ^{3, and more} preferably 1.15×10 ³ to 1.30×10 ³ kg/m ³ .

The apparent density D of the expanded particles is preferably in the range of ^{20 to 640 kg/m 3.} When the apparent density D is less than 20 kg/m ³ , the bubble film may become thin and the bubble film may burst during molding, the ratio of continuous bubbles may increase, and the foam particles may shrink due to bubble buckling. When the apparent density D is greater than 640 kg/m ³ , the bubble film may become thicker and the moldability may decrease. The apparent density D is preferably 40 to 400 kg/m ^{3 and more} preferably 50 to 250 kg/m ³ .

The thickness of the bubble wall is preferably in the range of 1 to 15 μm. When the average cell wall thickness is less than 1 μm, the moldability during molding may deteriorate, especially the fusion may deteriorate. When the average cell wall thickness is greater than 15 μm, it may become difficult to increase the magnification. The average cell wall thickness is preferably 1 to 10 μm, more preferably 1 to 5 μm.

1-5. Continuous bubble rate

The continuous bubble rate is preferably 0 to 10%. When the open cell ratio is greater than 10%, the moldability of the foamed molded product may decrease. The continuous bubble rate is preferably 0 to 5%.

1-6. Polycarbonate resin

The polycarbonate resin as the base resin of the expanded particles may be a linear polycarbonate resin or a branched polycarbonate resin.

The polycarbonate resin is preferably a polyester structure having carbonic acid and diol or dihydric phenol. The polycarbonate resin may have an aliphatic skeleton, an alicyclic skeleton, an aromatic skeleton, and the like. From the viewpoint of further improving the heat resistance, the polycarbonate resin system preferably has an aromatic skeleton. Specific examples of polycarbonate resins include: 2,2-bis(4-oxyphenyl)propane, 2,2-bis(4-oxyphenyl)butane, 1,1-bis( 4-oxyphenyl)cyclohexane, 1,1-bis(4-oxyphenyl)butane, 1,1-bis(4- Polycarbonate resins derived from bisphenols, such as oxyphenyl)isobutane, 1,1-bis(4-oxyphenyl)ethane, and the like.

The polycarbonate resin may contain other resins other than polycarbonate resin. Examples of other resins include acrylic resins, saturated polyester resins, ABS resins, polystyrene resins, polyolefin resins, and polyphenylene ether resins. Among the polycarbonate resins, it is preferable to contain 50% by weight or more of the above-mentioned polycarbonate resin.

In addition, the polycarbonate resin system preferably has an MFR of 1.0 to 20.0 g/10 minutes, and more preferably 2.0 to 15.0 g/10 minutes. Resins with MFR in this range are suitable for foaming, and it is easy to increase foaming. Moreover, the polycarbonate resin preferably has an MFR of 1.0 to 15.0 g/10 minutes, more preferably 1.0 to 14.0 g/10 minutes, and even more preferably 1.0 to 12.0 g/10 minutes. The resin system in this range can suitably realize the variation rate X of the foamed molded article described later.

1-7. Shape of expanded particles

The shape of the expanded particles is not particularly limited. For example, a spherical shape, a cylindrical shape, etc. can be mentioned. Among them, it is better to be as close to the spherical shape as possible. That is, the ratio of the short diameter to the long diameter of the expanded particles is preferably as close to 1 as possible.

The expanded particles preferably have an average particle diameter of 1 to 20 mm. The average particle size is the value shown in D50 obtained by classification using a Ro-Tap (trade name) vibrating sieve shaker.

1-8. Manufacturing method of expanded particles

The expanded particle system can be obtained by impregnating resin particles with a foaming agent to obtain expandable particles, and by foaming the expandable particles.

1-8-1. Manufacturing of expandable particles

The expandable particle system can be obtained by impregnating a foaming agent with resin particles made of a polycarbonate resin.

The resin particles can be obtained by a known method. For example, the polycarbonate resin may be melt-kneaded and extruded in an extruder together with other additives as necessary to obtain strands, and the obtained strands are carried out in the air. Cutting, cutting in water, heating and cutting, and the method of granulation. As the resin particles, commercially available resin particles may also be used. The resin particle system may contain other additives in addition to the resin as needed. Other additives may include: plasticizers, flame retardants, flame retardant additives, antistatic agents, spreaders, bubble regulators, fillers, colorants, weathering agents, anti-aging agents, antioxidants, and ultraviolet absorbers , Smoothing agent, anti-fogging agent and perfume, etc.

Secondly, as the blowing agent system impregnated in the resin particles, known volatile blowing agents and inorganic blowing agents can be used. Examples of volatile blowing agents include aliphatic hydrocarbons such as propane, butane, and pentane; and aromatic hydrocarbons, alicyclic hydrocarbons, and aliphatic alcohols. Examples of the inorganic foaming agent include carbon dioxide gas, nitrogen, air, and inert gas (helium, argon, etc.). Two or more of these foaming agents may be used in combination. Among these foaming agents, inorganic foaming agents are preferred, and carbon dioxide gas is more preferred.

The content (impregnation amount) of the foaming agent is preferably 3 to 15 parts by weight relative to 100 parts by weight of the polycarbonate resin. When the content of the foaming agent is less than 3 parts by weight, the foaming power may become low and it may be difficult to foam well. When the content exceeds 15 parts by weight, the plasticizing effect becomes greater, shrinkage is likely to occur during foaming, and productivity becomes worse, and it may become difficult to stably obtain the desired expansion ratio. More preferably, the content of the foaming agent is 4 to 12 parts by weight.

The impregnation method includes: a wet impregnation method in which resin particles are dispersed in a water system, and a blowing agent is pressed in while stirring to impregnate them; and resin particles are poured into the air tightly. A dry impregnation method (gas phase impregnation method) that does not substantially use water by pressing the foaming agent into the container to impregnate it. The dry impregnation method that can impregnate without using water is particularly preferred. The impregnation pressure, impregnation time, and impregnation temperature when impregnating the foaming agent into the resin particles are not particularly limited.

From the viewpoint of efficiently performing impregnation and obtaining better expanded particles and expanded molded articles, the impregnation pressure is preferably 0.5 to 10 MPa (gauge pressure). It is better to use 1 to 4.5 MPa (gauge pressure).

The immersion time is preferably 0.5 to 200 hours. In the case of less than 0.5 hours, it may be difficult to obtain sufficient foaming power due to the decrease in the amount of foaming agent impregnated in the resin particles. In the case of longer than 200 hours, the productivity may decrease. The better impregnation time is 1 to 100 hours.

The impregnation temperature is preferably 0 to 60°C. When the temperature is lower than 0°C, the solubility of the foaming agent in the resin increases, and it is necessary to impregnate the foaming agent more than necessary. Furthermore, the diffusibility of the foaming agent in the resin is reduced. Therefore, it may be difficult to obtain sufficient foaming power (primary foaming power) within a desired time. When it is higher than 60°C, the solubility of the foaming agent in the resin decreases, and the impregnation amount of the foaming agent decreases. Furthermore, the diffusibility of the foaming agent in the resin is improved. Therefore, it may be difficult to obtain sufficient foaming power (primary foaming power) within a desired time. More preferably, the impregnation temperature is 5 to 50°C.

Surface treatment agents such as anti-blocking agent (anti-aggregation agent), antistatic agent and spreading agent can also be added to the impregnated material.

The aforementioned anti-blocking agent functions to prevent the foamed particles from sticking to each other during the foaming step. Here, the so-called bonding refers to the merging and integration of a plurality of expanded particles. Specific examples of the aforementioned anti-blocking agent include talc, calcium carbonate, aluminum hydroxide, and the like.

Examples of the aforementioned antistatic agent include polyoxyethylene alkylphenol ether, stearic acid monoglyceride, and the like.

Examples of the aforementioned spreading agent include polybutene, polyethylene glycol, and silicone oil.

1-8-2. Manufacturing of expanded particles

As a method of foaming expandable particles to obtain expanded particles (primary expanded particles), there are: heating the expandable particles with a heat medium such as hot air, oil, steam (steam), etc. Method of foaming. For stable production, steam is preferred.

The foaming machine at the time of foaming is preferably a sealed and pressure-resistant foaming container. In addition, the pressure of the steam is preferably 0.10 to 0.80 MPa (gauge pressure), more preferably 0.25 to 0.45 MPa (gauge pressure). The foaming time may be the time required to obtain the desired foaming ratio. More preferably, the foaming time is 5 to 180 seconds. When it exceeds 180 seconds, the expanded particles may start to shrink, and there may be cases in which expanded molded articles with good physical properties cannot be obtained from the expanded particles.

The above-mentioned anti-blocking agent can also be removed before forming. As far as the removal method is concerned, it is better to wash with an acidic aqueous solution such as water or hydrochloric acid.

1-8-3. Adjustment of bubble density X and average bubble wall thickness

In the above-mentioned production steps of expanded particles, the cell density X and average cell wall thickness can be adjusted by adjusting the impregnation conditions (impregnation pressure, impregnation time, impregnation temperature) and primary foaming conditions (foaming pressure, foaming time). Increase or decrease.

1-8-4. Adjustment of volume multiple and average bubble diameter

In the manufacturing steps of the above-mentioned expanded particles, the volume multiple and average bubble diameter can be determined by adjusting the impregnation conditions (impregnation pressure, impregnation time, impregnation temperature) and primary foaming conditions (foaming pressure, foaming time). Increase or decrease.

2. Foam molding

The foam molding system can be composed of multiple foam beads using polycarbonate resin as the base resin Son get. Here, the expanded particles are preferably any one selected from the group consisting of the above-mentioned first expanded particles and second expanded particles.

2-1. Bubble density X

The cell density X can be calculated from the expanded particles constituting the expanded molded article. The cell density X system can be calculated from the following formula similarly to the above-mentioned expanded particles:

Bubble density X=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ }. Here, D is the density of the foamed molded article.

The cell density X system can be 1.0×10 ⁶ cells/cm ³ or more and less than 1.0×10 ⁸ cells/cm ³ . The reason for setting the cell density X to the specific range is the same as the reason for the above-mentioned expanded particles. The preferable range and the more preferable range of the cell density X are the same as the respective ranges of the above-mentioned expanded particles.

In addition, the preferable range of the average cell diameter C and the density ρ of the polycarbonate resin, the reason for setting the range, the more preferable range, and the more preferable range are the same as the above-mentioned expanded particles, respectively.

The density D of the foamed molded product is preferably in the range of ^{12 to 600 kg/m 3.} When the density D is less than 12 kg/m ³ , the bubble film may become thinner, and the bubble film may burst during molding, the ratio of continuous bubbles may increase, and the strength of the molded body may deteriorate. When the density D is greater than 600 kg/m ³ , the bubble film may become thicker and the moldability may decrease. More preferably the density D of 24 to 240kg / m ^3, and more preferably the density D of 30 to 120kg / m ^3.

2-2. Average bubble wall thickness

The average bubble wall thickness can be set to 1 to 15 μm. The reason for setting the average cell thickness in the specific range is the same as the reason for the above-mentioned expanded particles. The preferable range and the more preferable range of the average cell wall thickness are the same as each range of the said expanded particle, respectively.

2-3. The average bubble diameter of the foamed body divided by the multiple of the foamed body value

The value obtained by dividing the average cell diameter of the foamed molded article by the multiple of the foamed molded article shows a value in the range of 2.5 to 12 μm/time. If the value is less than 2.5 μm/time, the foamed film may become thin and the bubbles may buckle, which may cause shrinkage of the expanded particles. As a result, the mechanical strength of the foamed molded product may decrease. When the value is more than 12 μm/time, the bubble film becomes thicker and the moldability is lowered. As a result, the mechanical strength of the foamed molded product may be lowered. The value is preferably 3.0 to 10.0 μm/time, more preferably 3.0 to 6.5 μm/time.

The multiple is preferably in the range of 2 to 20 times. When the multiple is less than 2 times, the bubble film may become thicker and the moldability may decrease, and the fusion of the expanded particles may decrease during molding. When the multiple is more than 20 times, the bubble film may become thinner, and the bubble film may be broken during molding, the ratio of continuous bubbles may increase, and the strength of the molded body may deteriorate. The multiple is preferably 3 to 18 times, and even more preferably 5 to 16 times.

2-4. Bubble number density

The cell number density X can be calculated from the expanded particles constituting the foamed molded article. The cell number density is the same as the above-mentioned expanded particles and can be calculated from the following formula:

Bubble number density=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ }. Here, D is the density of the foamed molded article.

The cell number density X is preferably 1.0×10 ⁷ to 1.0×10 ⁹ cells/cm ³ . When the cell number density is outside the above-mentioned specific range, the moldability may be poor and the mechanical strength may decrease. The preferable range and the more preferable range of the cell number density are the same as each range of the said expanded particle, respectively.

In addition, the preferable range of the average cell diameter C and the density ρ of the polycarbonate resin, the reason for setting the range, the more preferable range, and the more preferable range are the same as the above-mentioned expanded particles, respectively.

The density D of the foamed molded product is preferably in the range of ^{12 to 600 kg/m 3.} When the density D is less than 12 kg/m ³ , the bubble film may become thinner, and the bubble film may burst during molding, the ratio of continuous bubbles may increase, and the strength of the molded body may deteriorate. When the density D is greater than 600 kg/m ³ , the bubble film may become thicker and the moldability may be lowered, and the fusion of the expanded beads during molding may be lowered. Density D lines 24 to 240kg / m ³ is more preferably, 30 to 120kg / m ³ and more preferably is.

The foam molding system preferably has an average cell wall thickness in the range of 1 to 15 μm. If the average cell wall thickness is less than 1 μm, the moldability during molding, especially fusion, may deteriorate. When the average cell wall thickness is greater than 15 μm, it may become difficult to increase the magnification. The average cell wall thickness is preferably 1 to 10 μm, and even more preferably 1 to 5 μm.

2-5. Continuous bubble rate

The continuous bubble rate is preferably 0 to 50%. When the continuous bubble rate is greater than 50%, the mechanical strength may decrease. The continuous bubble rate is more preferably from 0 to 40%, more preferably from 0 to 30%, and particularly preferably from 0 to 25%.

2-6. Foaming multiple

The expansion ratio is preferably in the range of 3 to 30 times. When the multiple is less than 3 times, the foam film of the expanded particles may become thicker, and the fusion of the expanded particles may decrease during molding. When the multiple is more than 30 times, the bubble film may become thinner and the bubble film may be broken during foaming, the ratio of continuous bubbles may increase, and the strength of the molded body may deteriorate. The multiple is preferably 4 to 20 times, and even more preferably 4 to 15 times.

2-7. Rate of change X

For the foam molding system, the maximum point stress of the 4-point bending test was measured at each temperature of -40℃, 23℃, 80℃ and 140℃, and the maximum point stress of the 4-point bending test was calculated. In the average value, the value of the maximum point stress of the 4-point bending test relative to the average value of the change rate X is in the range of 0 to 50%.

In addition, the rate of variation X is calculated in accordance with the following procedure when the maximum point stress in the 4-point bending test is A, B, C, and D. First, for A, calculate the respective rate of change X _A according to the following formula:

|Average value of maximum point stress in bending test-A|/Average value of maximum point stress in bending test×100. Similarly, for B, C, and D, the respective rates of change X _B , X _C and X _D are calculated. The highest value among the obtained four respective rates of change is set as the rate of change X.

The inventors of the present invention have found that by making a foamed molded body exhibit this rate of change X, it is possible to provide a foamed molded body that can suppress changes in mechanical strength even if the ambient temperature changes. When the variation rate X is outside the range of 0 to 50%, it will be difficult to obtain a foamed molded product whose mechanical strength changes due to changes in ambient temperature are suppressed. The variation rate X is preferably in the range of 0 to 45%, and more preferably in the range of 0 to 40%.

For example, the maximum point stress of the bending test at 140°C is preferably 0.5 MPa to 20.0 MPa. When the maximum point stress of the bending test is less than 0.5 MPa, the strength may be insufficient and become unbearable. When the maximum point stress in the bending test is greater than 20.0 MPa, it may become easy to break due to impact. The maximum point stress of the bending test is preferably 0.5 to 10.0 MPa, and even more preferably 0.6 to 5.0 MPa.

2-8. Rate of change Y

In the foam molding system, the 4-point value of the maximum point stress of the bending test at each temperature of -40°C, 23°C, 80°C, and 140°C is divided by the density of each foam molding to calculate the 4-point "bending" test When calculating the average value of the 4-point “maximum point stress/density of the bending test”, the value of the 4-point “maximum point stress/density of the bending test” is relative to the average value. The rate of change Y is preferably in the range of 0 to 50%. By having this rate of change, it is possible to provide a foamed molded product that is stronger against changes in ambient temperature. The rate of change Y is preferably in the range of 0 to 45%, and more preferably in the range of 0 to 40%.

In addition, regarding the average value of the 4-point "maximum point stress/density of the bending test", the group of the maximum point stress and density of the 4-point bending test is A and a, B and b, and C and c. , And D and d can be calculated by the following formula:

(A/a+B/b+C/c+D/d)/4.

The rate of change Y is calculated by the following procedure when the groups of the maximum point stress and density of the 4-point bending test are A and a, B and b, C and c, and D and d. First, for A and a, the respective rate of change Y _Aa is calculated according to the following formula:

|Average value of "Maximum point stress/density of bending test"-A/a|/Average value of "Maximum point stress/density of bending test"×100. _{Similarly, the respective rates of change Y Bb} , Y _Cc and Y _{Dd are} calculated for B and b, C and c, and D and d. Among the obtained four respective rates of change, the one with the largest value is set as the rate of change Y.

The density is preferably 30 to 400 kg/m ³ , and more preferably 50 to 300 kg/m ³ .

2-9. Degree of change Z

For the foamed molded product, the "maximum point stress of the bending test" at -40°C relative to the "maximum point stress of the bending test" at 23°C is based on the degree of change Z showing a change in the range of 0 to 0.88 good. By having this degree of change, it is possible to provide a foamed molded body that is stronger against environmental temperature changes. The degree of change Z is preferably from 0 to 0.7, and more preferably from 0 to 0.5.

In addition, the degree of change Z system can be calculated according to the following formula:

The degree of change Z=[(maximum point stress in the bending test at -40°C)-(maximum point stress in the bending test at 23°C)]÷(maximum point stress in the bending test at 23°C).

In addition, for the foamed molded product, the "maximum point stress of the bending test" at 80°C with respect to the "maximum point stress of the bending test" at 23°C shows the degree of change Z which varies from 0 to 0.6 'Better. By having this degree of change, it is possible to provide a foamed molded body that is stronger against environmental temperature changes. The degree of change Z'is preferably 0 to 0.5, more preferably 0 to 0.35.

In addition, the degree of change Z'can be calculated according to the following formula:

The degree of change Z'=[(maximum point stress in the bending test at 23°C)-(maximum point stress in the bending test at 80°C)]/(maximum point stress in the bending test at 23°C).

2-10. Polycarbonate resin

The polycarbonate resin system can use the same polycarbonate resin as the above-mentioned expanded particle.

2-11. Uses of foamed molded products

The foamed molded article is not particularly limited, and various shapes can be adopted depending on the application. For example, the foam molding system can respond to building materials (civil engineering related, housing related, etc.), automobile, aircraft, railway car, ship and other transportation equipment parts, windmills, helmets and other structural components, packaging materials, and FRP as composite components Various shapes are adopted for the core material and other purposes.

From the viewpoint of suppressing changes in mechanical strength even if the ambient temperature changes, automotive parts include, for example, parts used near the engine, coating materials, and the like. Examples of parts of the automobile include: floor, roof, hood, fender, lower cover, wheels, steering wheel, container (housing), hood panel, cantilever, bumper, sunshade, luggage Parts such as trunk lid, luggage box, seat, door, cowl, etc.

2-12. Manufacturing method of foam molding

The foaming molding system can be obtained, for example, by imparting the power to expand the bubbles to the above-mentioned foamed particles, and then putting the foamed particles into a forming step.

Before manufacturing the foamed molded article, it is preferable to impregnate the foaming agent in the foamed particles to impart foaming power (secondary foaming power).

The impregnation method includes: a wet impregnation method in which expanded particles are dispersed in a water system and a blowing agent is pressed in while stirring to impregnate them; and the expanded particles are poured into a sealed container, and The dry impregnation method (gas phase impregnation method) etc. which do not substantially use water for impregnating the foaming agent by pressing it in. In particular, a dry impregnation method that can impregnate without using water is preferred. The impregnation pressure, impregnation time, and impregnation temperature when impregnating the expanded particles with the foaming agent are not particularly limited.

The foaming agent used can be the foaming agent used in the production of expanded particles, such as known volatile foaming agents and inorganic foaming agents. Examples of volatile blowing agents include aliphatic hydrocarbons such as propane, butane, and pentane; and aromatic hydrocarbons, alicyclic hydrocarbons, and aliphatic alcohols. Examples of the inorganic foaming agent include carbon dioxide gas, nitrogen, air, and inert gas (helium, argon, etc.). Among them, it is particularly preferable to use an inorganic foaming agent. In particular, it is preferable to use one of nitrogen, air, inert gas (helium, argon), and carbon dioxide gas, or a combination of two or more of them. Regarding the pressure for imparting internal pressure, it is desirable that the expanded particle does not collapse and is within a range that can impart foaming force. Such pressure is preferably 0.1 to 4Mpa (gauge pressure), more preferably 0.3 to 3Mpa (gauge pressure). The impregnation of the expanded particles with the foaming agent in this manner is to impart an internal pressure.

The immersion time is preferably 0.5 to 200 hours. In the case of less than 0.5 hours, the amount of foaming agent impregnated in the expanded particles is too small, and it may be difficult to obtain the required secondary foaming force during molding. In the case of longer than 200 hours, productivity may decrease. more The best impregnation time is 1 to 100 hours.

The impregnation temperature is preferably 0 to 60°C. When the temperature is below 0°C, it may be difficult to obtain sufficient secondary foaming power within the desired time. When the temperature is higher than 60°C, it may be difficult to obtain sufficient secondary foaming power within the desired time. A more preferable impregnation temperature is 5 to 50°C.

After the expanded particles that have been given internal pressure are taken out of the impregnated container and supplied to the molding space formed in the molding die of the foam molding machine, they can be molded into the desired mold by introducing a heating medium. Foam molding. The foaming molding machine can be used: the EPS molding machine used to produce the foamed molded article from the expanded particles made of polystyrene resin, and the expanded particle made of the polypropylene resin to produce the expanded molded article The high-pressure specification forming machine used at the time. Regarding the heating medium, as the heating time becomes longer, the expanded particles may shrink and fusion failure may occur. Therefore, a heating medium capable of imparting high energy in a short time is desired. Such a heating medium is preferably water vapor.

The pressure of water vapor is preferably 0.2 to 1.0Mpa (gauge pressure). In addition, the heating time is preferably 10 to 90 seconds, and more preferably 20 to 80 seconds.

In addition, the adjustment of the cell density X and the average cell wall thickness can be achieved by adjusting the impregnation conditions (impregnation temperature) in the manufacturing step of the foamed molded article in addition to the use of expanded particles having the above-mentioned specific cell density X and average cell wall thickness. , Impregnation time, impregnation pressure), one-time foaming conditions (foaming pressure, foaming time) are adjusted to increase or decrease the cell density X and average cell wall thickness.

Moreover, in addition to the use of the above-mentioned expanded particles having a specific volume ratio and average bubble diameter, the adjustment of the volume ratio and average bubble diameter can also be achieved by adjusting the impregnation conditions (impregnation temperature, impregnation time, impregnation time, The impregnation pressure) and primary foaming conditions (foaming pressure, foaming time) are adjusted to increase or decrease the volume multiple and average bubble diameter.

In addition, the maximum point stress and density of the bending test can be adjusted by the impregnation conditions (impregnation temperature, impregnation time, impregnation pressure) and molding conditions (foaming pressure, foaming time) in the manufacturing steps of the foamed molded product. ) Is adjusted to increase or decrease the maximum point stress and density of the bending test.

2-13. Strengthen the complex

It is also possible to integrate the skin material layer on the surface of the foamed molded article and use it as a reinforced composite. When the foamed molded body is a foamed sheet, the skin material may be integrated in at least one area of the two surfaces of the foamed molded body, and it is not necessary to integrate the foamed molded body in both area layers. The build-up of the skin material may be determined depending on the use of the reinforced composite.

In particular, when considering the surface hardness and mechanical strength of the reinforced composite, the skin material is preferably integrated in two areas in the thickness direction of the foamed molded product.

The skin material is not particularly limited, and examples include fiber-reinforced plastics, metal sheets, and synthetic resin films. Among them, fiber reinforced plastic is preferred. The reinforced composite system with fiber reinforced plastic as the surface material is called fiber reinforced composite.

唑(poly-p-phenylene benzobisoxazole；PBO)纖維等有機纖維；硼纖維。強化纖維可一種單獨使用，亦可併用二種以上。尤其是以碳纖維、玻璃纖維及芳綸纖維為佳，以碳纖維為更佳。此等強化纖維雖然為輕量者，但還是具有優異的機械物性。 Reinforcing fibers constituting fiber reinforced plastics include: glass fiber, carbon fiber, silicon carbide fiber, alumina fiber, tyranno fiber (tyranno fiber), basalt fiber, ceramic fiber and other inorganic fibers; stainless steel fiber, steel fiber, etc. Metal fiber; aramid fiber (aramid fiber), polyethylene fiber, parylene benzodi

Organic fibers such as poly-p-phenylene benzobisoxazole (PBO) fibers; boron fibers. The reinforcing fiber may be used alone or in combination of two or more kinds. Especially carbon fiber, glass fiber and aramid fiber are preferable, and carbon fiber is more preferable. Although these reinforcing fibers are lightweight, they still have excellent mechanical properties.

Reinforced fiber is so strong that it can be used as a desired shape after processing Chemical fiber base material is preferred. Reinforced fiber substrates include: woven fabrics, knitted fabrics, non-woven fabrics made of reinforcing fibers, and fiber bundles (strands) made of reinforcing fibers in one direction are bundled (sewn). Fabrics and so on. The weaving method of the woven fabric includes plain weave, twilled weave, and satin weave. In addition, the yarns include synthetic resin yarns such as polyamide resin yarns and polyester resin yarns; and stitching yarns such as glass fiber yarns.

The reinforcing fiber base material may not be laminated but only one reinforcing fiber base material may be used, or a plurality of reinforcing fiber base materials may be laminated and used as a laminated reinforcing fiber base material. For the laminated reinforced fiber base material laminated with a plurality of reinforced fiber base materials, it is possible to use: (1) Prepare a plurality of sheets of only one type of reinforced fiber base material, and laminate these reinforced fiber base materials. Laminated reinforced fiber base materials; (2) Prepare multiple types of reinforced fiber base materials, and laminate reinforced fiber base materials on which these reinforced fiber base materials are laminated; and (3) Prepare multiple sheets of reinforced fiber base materials, which will strengthen Fiber bundles (strands) formed by doubling fibers in one direction are reinforced fiber substrates formed by bundling (sewing) with yarns, and these reinforced fiber substrates are different from each other in the fiber direction of the fiber bundles Laminated reinforcing fiber base material etc. which are laminated by means of direction, and the laminated reinforcing fiber base materials are integrated (sewn) with yarns.

Fiber-reinforced plastics are those in which synthetic resin is impregnated with reinforcing fibers.

The reinforced fibers are bonded and integrated by the impregnated synthetic resin. The method of impregnating the synthetic resin with the reinforcing fiber is not particularly limited. For example, (1) the method of impregnating the reinforcing fiber in the synthetic resin; (2) the method of applying the synthetic resin to the reinforcing fiber.

As for the synthetic resin impregnated with reinforcing fibers, either thermoplastic resin or thermosetting resin can be used, preferably thermosetting resin. The thermosetting resin impregnated with the reinforcing fiber is not particularly limited, and examples include epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, Polyurethane resin, polysiloxane resin, maleimide resin, vinyl ester resin, cyanate ester resin, and resin prepolymerized maleimide resin and cyanate ester resin, etc., epoxy Resins and vinyl ester resins are preferred because they have excellent heat resistance, impact absorption, or chemical resistance. The thermosetting resin may also contain additives such as curing agents and curing accelerators. In addition, the thermosetting resin may be used alone, or two or more types may be used in combination.

In addition, the thermoplastic resin impregnated with the reinforcing fiber is not particularly limited, and examples include olefin resins, polyester resins, thermoplastic epoxy resins, imine resins, thermoplastic polyurethane resins, thioether resins, and acrylic resins. Since the adhesiveness with the foamed molded product or the reinforcing fibers constituting the fiber-reinforced plastic have excellent adhesiveness with each other, polyester-based resins and thermoplastic epoxy resins are preferred. In addition, the thermoplastic resin may be used alone, or two or more types may be used in combination.

Thermoplastic epoxy resins include: polymers or copolymers of epoxy compounds and polymers having a linear structure; copolymers of epoxy compounds and monomers that can be polymerized with the epoxy compounds and having straight Chain structure copolymer. Specifically, as thermoplastic epoxy resins, for example, bisphenol A epoxy resins, bisphenol phenol epoxy resins, cresol novolak epoxy resins, phenol novolac epoxy resins, and phenol novolac epoxy resins can be cited. ) Type epoxy resin, cycloaliphatic type epoxy resin, long-chain aliphatic type epoxy resin, glycidyl ester type epoxy resin and glycidyl amine type epoxy resin, etc., with bisphenol A Type epoxy resin and bisphenol phenol type epoxy resin are better. Moreover, a thermoplastic epoxy resin may be used individually or in combination of 2 or more types.

The thermoplastic polyurethane resin includes a polymer having a linear structure obtained by polymerizing a diol and a diisocyanate. Examples of the glycol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, and the like. The diol series can be used alone or in combination of two the above. Examples of diisocyanates include aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. The diisocyanate may be used alone, or two or more of them may be used in combination. In addition, the thermoplastic polyurethane resin may be used alone, or two or more of them may be used in combination.

The content of synthetic resin in fiber reinforced plastic is preferably 20 to 70% by weight. When the content is less than 20% by weight, the adhesion between the reinforcing fibers and the adhesion between the fiber-reinforced plastic and the foamed molded product become insufficient, and the mechanical properties of the fiber-reinforced plastic and the fiber-reinforced composite cannot be improved sufficiently. The situation of mechanical strength. If it exceeds 70% by weight, the mechanical properties of the fiber-reinforced plastic may decrease, and the mechanical strength of the fiber-reinforced composite may not be sufficiently improved. The content is more preferably 30 to 60% by weight.

The thickness of the fiber reinforced plastic is preferably 0.02 to 2 mm, more preferably 0.05 to 1 mm. Although fiber reinforced plastics with a thickness within this range are lightweight, they still have excellent mechanical properties.

The weight per unit area of the fiber reinforced plastic is preferably 50 to 4000 g/m ^{2, more} preferably 100 to 1000 g/m ² . Although fiber reinforced plastics with a unit area weight within this range are lightweight, they still have excellent mechanical properties.

Next, the manufacturing method of the reinforced composite body will be explained. The method of integrating the skin material layer on the surface of the foamed molded article to produce a reinforced composite is not particularly limited. Examples include: (1) The skin material layered layer is integrated on the surface of the foamed molded article via an adhesive. The method; (2) The fiber-reinforced plastic formed by impregnating the reinforced fiber with a thermoplastic resin is laminated on the surface of the foamed product, and the thermoplastic resin impregnated in the reinforced fiber is used as a binder and the fiber-reinforced plastic forming material is used as The method of integrating fiber-reinforced plastic laminated on the surface of the foamed molded product; (3) Laminating the fiber-reinforced plastic formed by impregnating the reinforcing fiber with uncured thermosetting resin into the foam The surface of the molded body, and use the thermosetting resin impregnated in the reinforcing fiber as a binder to harden the thermosetting resin to form a fiber-reinforced plastic laminate on the surface of the foamed molded body; (4) The skin material heated to a softened state is set on the surface of the foamed molded body, and the skin material is pressed against the surface of the foamed molded body, thereby making the skin material deform along the surface of the foamed molded body as needed, and at the same time The method of lamination integration on the surface of the foamed molded body; and (5) the method of forming fiber reinforced plastics, etc. usually. From the viewpoint of a machine having excellent load resistance and the like in a high-temperature environment, the foamed molded product can also be suitably used in the method (4).

The methods used in the molding of fiber reinforced plastics include, for example, the autoclave method, the hand lay-up method, the spray up method, and the PCM (Prepreg Compression Molding). Method, RTM (Resin Transfer Molding) method and VaRTM (Vacuum Assisted Resin Transfer Molding) method, etc.

The fiber-reinforced composite obtained in this way is excellent in heat resistance, mechanical strength, and light weight. Therefore, it can be used in a wide range of applications such as transportation equipment such as automobiles, aircrafts, railway vehicles, ships, etc., home appliances, information terminals, and furniture.

For example, the fiber-reinforced composite system can be suitably used in conveying machine components (especially automotive parts), wind turbine wings, robotic arms, cushions for helmets, including parts of conveying machines, and structural parts that constitute the main body of the conveying machine. Materials, transportation containers such as agricultural production boxes, heat preservation and cold storage containers, as well as rotator blades and parts packaging materials for industrial helicopters.

According to the present invention, it is possible to provide automobile parts composed of the fiber-reinforced composite of the present invention. The automobile parts include, for example, a floor, a roof, a hood, a fender, a lower cover, a wheel, a steering wheel, and a container (housing ), cover, cantilever, bumper, shading plate, trunk lid, trunk, seat Parts such as chairs, doors and fairings.

Example

Hereinafter, the present invention will be specifically explained with examples, but the present invention is not limited to these. First, the measurement methods of various physical properties in the examples are described below.

[Density of polycarbonate resin]

The density of the polycarbonate resin is measured using the method specified in ISO1183-1:2004 or ASTM D-792.

[Blowing agent impregnation content]

The amount of foaming agent impregnation is a value calculated in accordance with the following formula.

Foaming agent impregnation amount (wt%) = (weight immediately after impregnation-weight before impregnation) / weight before impregnation × 100

[The average particle size]

The average particle size is set to the value represented by 0 in D5.

Specifically, the Ro-Tap type vibrating sieving machine (manufactured by Iida Manufacturing Co., Ltd.) is used and the mesh size is 26.5mm, 22.4mm, 19.0mm, 16.0mm, 13.2mm, 11.20mm, 9.50mm, 8.80mm, 6.70mm, 5.66mm, 4.76mm, 4.00mm, 3.35mm, 2.80mm, 2.36mm, 2.00mm, 1.70mm, 1.40mm, 1.18mm, 1.00mm, 0.85mm, 0.71mm, 0.60mm, 0.50mm, 0.425mm, 0.355mm , 0.300mm, 0.250mm, 0.212mm, and 0.180mm JIS standard sieves (JIS Z8801-1: 2006), about 25 g of samples were classified for 10 minutes, and the weight of the samples on the sieves was measured. Create a cumulative weight distribution curve based on the obtained results, and set the particle size (median diameter) at which the cumulative weight becomes 50% as the average particle size.

[Average bubble diameter of expanded particles]

The expanded particles obtained by one-stage foaming are extracted to obtain the central part of the expanded particles. The central part of the cross section formed by roughly halving the central part of the expanded particles is enlarged to 200 with a scanning electron microscope. To 1200 times and shoot. Print the captured image on A4 paper. Draw three arbitrary straight lines (length 60mm) in the vertical and horizontal directions on the cross-sectional image of the expanded particles. When there is a bubble with an extremely large bubble diameter, avoid the bubble and separate in each direction. Draw 3 arbitrary straight lines.

In addition, an arbitrary straight line is performed as far as possible not only to touch the bubble at the tangent point, and if it touches, the bubble is also included in the count. The number of bubbles calculated for three arbitrary straight lines in each of the vertical and horizontal directions is arithmetic averaged and set as the number of bubbles.

From the image magnification for calculating the number of bubbles and the number of bubbles, the average chord length t of the bubbles is calculated according to the following formula.

Average chord length t(mm)=60/(number of bubbles×image magnification)

The image magnification is calculated by measuring the scale bar on the image to 1/100mm with the "Digimatic Caliper" manufactured by Mitutoyo Corporation, and it is calculated according to the following formula.

Image magnification = measured value of the scale (mm)/displayed value of the scale (mm)

Furthermore, the bubble diameter was calculated according to the following formula.

Average bubble diameter C(μm)=(t/0.616)×1000

[Average bubble diameter of foamed molded product]

Cut out a piece of 50mm×50mm×30mm from the center of the molded body of length 400mm×width 300mm×thickness 30mm, and magnify the cross section of the cut molded body sheet in the thickness direction to 200 to 1200 times with a scanning electron microscope. Shoot. Print the captured image on A4 paper. On the cross-sectional image of the foamed molded product, any of 3 parallel lines are drawn in the longitudinal direction and the lateral direction. The straight line (length 60mm), when there is a bubble with an extremely large bubble diameter, avoid the bubble and draw three arbitrary straight lines in each direction.

In addition, an arbitrary straight line is performed as far as possible not only to touch the bubble at the tangent point, and if it touches, the bubble is also included in the count. The number of bubbles calculated for three arbitrary straight lines in each of the vertical and horizontal directions is arithmetic averaged and set as the number of bubbles.

From the image magnification for calculating the number of bubbles and the number of bubbles, the average chord length t of the bubbles is calculated according to the following formula.

Average chord length t(mm)=60/(number of bubbles×image magnification)

The image magnification is calculated by measuring the scale on the image to 1/100mm using the "Digimatic Caliper" manufactured by Mitutoyo, and it is calculated according to the following formula.

Image magnification = measured value of the scale (mm)/displayed value of the scale (mm)

Furthermore, the average bubble diameter was calculated according to the following formula.

Average bubble diameter C(μm)=(t/0.616)×1000

[Bulk density and volume multiple of expanded particles]

Fill the measuring cylinder with about 1000 cm ^{3 of} expanded particles up to the scale of ^{1000 cm 3.} In addition, when the measuring cylinder was visually observed from the horizontal direction, even if only one expanded particle reached ^{the scale of 1000 cm 3} , the filling of the expanded particle into the measuring cylinder was completed at that point in time. Next, the weight of the expanded particles filled in the measuring cylinder was weighed to two significant figures below the decimal point, and the weight was set to Wg. In addition, the bulk density of the expanded particles is obtained according to the following equation.

Bulk density (kg/m ³ )=(W/1000)/[1000×(0.01) ³ ]

The volume multiple is a value obtained by ^{adding up the density (kg/m 3} ) of the polycarbonate resin by the reciprocal of the volume density.

[Apparent density and apparent multiple of expanded particles]

The weight A (g) of ^{about 25 cm 3} of the expanded particles was measured. Next, the empty container made of metal mesh that does not overflow the expanded particles placed with the lid closed is immersed in water, and the weight of the empty container made of metal mesh in the state of being immersed in water B (g ). Next, when the total amount of the aforementioned expanded particles has been placed in the metal mesh container, the metal mesh container is immersed in water, and the container is vibrated several times to remove the particles attached to the container and the expanded particles. After the bubbles were removed, the combined weight C (g) of the metal mesh container in the state of being immersed in water and the total amount of expanded particles put in the metal mesh container was measured. In addition, the apparent density D (kg/m ³ ) of the expanded particles was calculated according to the following formula.

D=A/(A+(B-C))×1000

The apparent multiple is a value obtained by ^{adding up the density (kg/m 3} ) of the polycarbonate resin by the reciprocal of the apparent density.

[Density and expansion ratio of foamed molded product]

The density (kg/m ³ ) of the foamed molded product is measured by measuring the test piece cut out from the foamed molded product (the one that has been dried at 40°C for more than 20 hours after molding) with significant figures reaching 3 digits or more ( The weight (a) and volume (b) (width 75mm×length 300mm×thickness 30mm) are calculated by formula (a)/(b) (condition A); or the effective digits are more than 3 digits To measure the weight (a) and volume (b) of a test piece (width 25mm×length 130mm×thickness 20mm) cut out from the foamed molded product (after being dried at 50°C for 5 hours or more), and by formula (a )/(b) Find (condition B).

The measurement was performed at a temperature of 23°C.

The value obtained by ^{adding up the density (kg/m 3} ) of the polycarbonate-based resin by the reciprocal of the expansion ratio-based density.

[Continuous cell rate of expanded particles]

A sample cup of "Air Comparator 1000" manufactured by Tokyo Science Co., Ltd. was prepared, and the total weight A (g) of the expanded particles that was about 80% of the sample cup was measured. Use an air-comparative hydrometer to measure the volume B (cm ³ ) of the foamed particles as a whole by the 1-1/2-1 atmospheric pressure method, and use a standard ball (larger 28.96cm ³ , smaller 8.58cm ³ ) for correction . Next, the empty container made of metal mesh that does not overflow the expanded particles placed with the lid closed is immersed in water, and the weight of the empty container made of metal mesh in the state of being immersed in water C (g) is measured . Next, when the total amount of the aforementioned expanded particles has been placed in the metal mesh container, the metal mesh container is immersed in water, and the container is vibrated several times to remove the particles attached to the container and the expanded particles. After the bubbles were removed, the combined weight D (g) of the metal mesh container in the state of being immersed in water and the total amount of expanded particles put into the metal mesh container was measured. In addition, the apparent volume E (cm ³ ) of the expanded beads was calculated by the following formula. Based on this apparent volume E (cm ³ ) and the volume B (cm ³ ) of the entire expanded particle as described above, the open cell ratio of the expanded particle was calculated by the following formula.

E=A+(C-D)

Continuous bubble rate (%)=100×(E-B)/E

[Continuous cell rate of foamed molded product]

The foam is cut out in such a way that none of the six sides of the molded body have a molded surface skin, and the cross-sectional surface is processed by a "FK-4N" bread slicer manufactured by Fujishima Koki Co., Ltd. to produce 5 A cube-shaped test piece with a width of 25 mm × a length of 25 mm × a thickness of 25 mm. The outer dimensions of the obtained test piece were measured to 1/100 mm using a "Digimatic Caliper" made by Mitutoyo, and the apparent volume (cm ³ ) was determined. ^{Next, the volume (cm 3} ) of the test piece was obtained by the 1-1/2-1 atmospheric pressure method using the "1000" air-comparative hydrometer manufactured by Tokyo Science Corporation. The continuous bubble rate (%) was calculated by the following formula, and the average value of the continuous bubble rate of 5 test pieces was calculated. The test piece was stored in a JIS K7100: 1999 mark 23/50, class 2 environment for 16 hours, and then the measurement was performed in the same environment. In addition, the air-comparative hydrometer is corrected by using a standard ball (larger 28.96cm ³ , smaller 8.58cm ³ ).

Continuous bubble rate (%) = (apparent volume-volume measured using air comparison hydrometer) / apparent volume × 100

[Average cell wall thickness of expanded particles]

The average cell wall thickness of the expanded particles is calculated as follows. Using the average cell diameter and apparent multiple of the expanded particles obtained by the above-mentioned measuring method, they were calculated according to the following formula.

Average bubble wall thickness (μm) = average bubble diameter C (μm) × (1/(1-(1/apparent multiple)) ^(1/3) -1)

[Average cell wall thickness of foam molded product]

The average cell wall thickness of the foamed molded article is calculated as follows. The average cell diameter and multiple of the foamed molded article obtained by the above-mentioned measuring method are used to calculate according to the following formula.

Average bubble wall thickness (μm) = average bubble diameter C (μm) × (1/(1-(1/multiple)) ^(1/3) -1)

[Bending test: density, load, stress, displacement and energy at the maximum point]

The load, stress, displacement and energy at the maximum point are measured by the method in accordance with JISK7221-1: 2006 "Rigid Foam Plastics-Flexural Test-Part 1: How to Obtain Flexural Characteristics". That is, a rectangular parallelepiped test piece having a width of 25 mm × a length of 130 mm × a thickness of 20 mm was cut out from the molded foam. The measurement system uses a TENSILON universal testing machine ("UCT-10T" manufactured by ORIENTEC). The bending strength of the maximum bending point stress system uses a universal testing machine data processing system System ("UTP S-237S Ver, 1.00" manufactured by Softbrain).

Place the short tab-shaped test piece on the support table, and measure the maximum bending stress under the conditions of a load cell of 1000N, a test speed of 10mm/min, a jig at the end of the support table 5R, and an opening width of 100mm. The number of test strips is set to 5 or more. After adjusting the condition for 16 hours under JISK7100: 1999 notation "23/50" (temperature 23°C, relative humidity 50%), and level 2 standard gas environment, the same Measured under the standard gas environment. After adjusting the state in a constant temperature bath that has been set at each test temperature of -40°C, 80°C, and 140°C for 24 hours, immediately install the fixture in the constant temperature bath attached to the device that has been set at each specified temperature , And the measurement is performed after 3 minutes.

The arithmetic mean value of the bending maximum point stress of each test piece was set as the bending maximum point stress of the foam molding, respectively.

In addition, the maximum bending point stress per unit density is calculated by dividing the maximum bending point stress by the density of the foamed molded article.

In addition, the density (kg/m ³ ) of the foamed molded body is determined by measuring the weight (a) and volume (b) of the test piece cut out from the foamed molded body, and is calculated from the formula (a)/(b) .

[Bending test: modulus of elasticity]

The flexural modulus of elasticity is measured by a method in accordance with JIS K7221-1: 2006 "Rigid foamed plastics-Bend test-Part 1: Determination of flexural characteristics". That is, a rectangular parallelepiped test piece with a width of 25 mm × a length of 130 mm × a thickness of 20 mm was cut out from the molded foam. The measurement was performed using a TENSILON universal testing machine ("UCT-10T" manufactured by ORIENTEC). The flexural modulus of elasticity is calculated by the following formula using a universal testing machine data processing system ("UTP S-237S Ver, 1.00" manufactured by Softbrain Corporation). The number of test pieces is set to 5 or more, in JIS K7100: 1999 notation "23/50" (temperature 23°C, relative humidity 50%), it takes 16 hours to adjust the state in a Class 2 standard gas environment, and then perform the measurement in the same standard gas environment. The arithmetic mean value of the compressive elastic modulus of each test piece was made into the flexural elastic modulus of the foam molding, respectively.

The bending elastic modulus is calculated according to the following formula using the straight part at the beginning of the load-deformation curve.

E=△σ/△ε

E: bending elastic modulus (MPa)

△σ: The difference in stress between two points on the straight line (MPa)

△ε: The difference in deformation between the same two points (%)

In addition, the flexural modulus per unit density is calculated by dividing the flexural modulus by the density of the foamed molded article.

[Compression test: density, and 5%, 10%, 25% and 50% stress]

The 5% compressive stress, 10% compressive stress, 25% compressive stress, and 50% compressive stress of the molded foam are measured by the method described in JIS K7220: 2006 "Rigid Foam Plastics-Determination of Compressive Properties" . That is, using the TENSILON universal testing machine ("UCT-10T" manufactured by ORIENTEC) and the universal testing machine data processing system ("UTPS-237S Ver, 1.00" manufactured by Softbrain), the size of the test body is 50mm×50mm in cross section and thickness At 25 mm, the compression speed was set to 2.5 mm/min, and the compression strength (5% deformation compression stress, 25% deformation compression stress, and compression elastic modulus) was measured. The number of test strips is set to 5 or more. After the condition adjustment is performed in the JIS K7100: 1999 notation "23/50" (temperature 23°C, relative humidity 50%), and a level 2 standard gas environment, it takes 16 hours to adjust Measure under the same standard gas environment. Put each test piece The arithmetic mean values of the compressive strength (5% deformation compression stress, 10% deformation compression stress, 25% deformation compression stress, 50% deformation compression stress) are set as the 5% compression stress, 10% compression stress, and 25% compressive stress, 50% compressive stress.

(5% (10%, 25%, 50%) deformation compression stress)

5% (10%, 25%, 50%) deformation compression stress is calculated according to the following formula. In addition, () sets the conditions for calculating 10% deformation compression stress, 25% deformation compression stress, and 50% deformation compression stress.

σ5(10, 25, 50)=F5(10, 25, 50)/A ₀

σ5 (10, 25, 50): 5 (10%, 25%, 50%) deformation compression stress (MPa)

F5 (10, 25, 50): 5 (10%, 25%, 50%) force during deformation (N)

A ₀ ：The initial cross-sectional area of the test piece (mm ² )

[Compression test: modulus of elasticity]

The compression modulus of the foamed molded article is measured using the method described in JISK7220:2006 "Rigid Foam Plastics-Method for Obtaining Compression Properties". That is, using the TENSILON universal testing machine ("UCT-10T" manufactured by ORIENTEC) and the universal testing machine data processing system ("UTPS-237S Ver, 1.00" manufactured by Softbrain), the size of the test body is 50mm×50mm in cross section and thickness At 25 mm, the compression speed was set to 2.5 mm/min, and the compression modulus of elasticity was calculated according to the following formula. The number of test strips is set to 5 or more. After adjusting the state in JIS K7100: 1999 notation "23/50" (temperature 23°C, relative humidity 50%), and a level 2 standard gas environment, it takes 16 hours to adjust the condition. Measure under the same standard gas environment. The arithmetic average value of the compressive elastic modulus of each test piece was taken as the compressive elastic modulus of the foamed molded article.

The compressive modulus of elasticity is calculated using the straight part at the beginning of the load-deformation curve according to the following formula.

E=△σ/△ε

E: bending elastic modulus (MPa)

△σ: The difference in stress between two points on the straight line (MPa)

△ε: The difference in deformation between the same two points (%)

In addition, the flexural modulus per unit density is calculated by dividing the flexural modulus by the density of the foamed molded article.

Example 1a

(Procedure for manufacturing resin particles)

The polycarbonate resin particles (PANLITE L-1250Y manufactured by Teijin Corporation, density 1.2×10 ³ kg/m ³ ) were dried at 120° C. for 4 hours. The obtained dried product was supplied to a uniaxial extruder with a diameter of 40 mm at a rate of 10 kg/hr per hour, and was melt-kneaded at 290°C. Next, it was extruded from the die hole (equipped with 4 nozzles with a diameter of 1.5 mm) of the die head (temperature: 290°C, inlet side resin pressure: 13 MPa) installed at the tip of the single-screw extruder to approximately 10°C. In the processing chamber of the cooling water, the rotating shaft of the rotating blade with 4 cutting blades is rotated at 5000 rpm to cut into granules, and the cooling water is used to cool the resin particles (average particle size) 1.4mm).

(Impregnation step)

After sealing 100 parts by weight of the resin particles in a pressure vessel and replacing the inside of the pressure vessel with carbon dioxide gas, the carbon dioxide gas was pressure-injected to an impregnation pressure of 1.5 MPa. Let it stand in an environment of 20°C and after 24 hours of impregnation time, it takes 5 minutes to slowly depressurize the pressure vessel. In this way, the resin particles are impregnated with carbon dioxide gas to obtain expandable particles. In addition, the foaming agent impregnation amount at this time was 4.8% by weight.

(Foaming step)

After depressurization in the above impregnation step, the expandable particles are immediately taken out from the pressure vessel, and then stirred with water vapor at a foaming temperature of 142°C for 48 seconds. At the same time, the above-mentioned impregnation is made by water vapor in a high-pressure foaming tank.物foaming. After foaming, it was dried with a jet dryer to obtain expanded particles. The bulk density of the obtained expanded particles measured by the above-mentioned method was 109 kg/m ³ (expansion ratio 10.95 times).

(Forming step)

After the obtained expanded particles were left at room temperature (23°C) for one day, the pressure vessel was sealed in a pressure vessel and the pressure vessel was replaced with nitrogen, and then the nitrogen gas was pressure-injected to an impregnation pressure (gauge pressure) of 1.6 MPa. It was allowed to stand still in an environment of 20°C and subjected to pressure maturation for 24 hours. After taking it out, it is filled into a molding mold of 30mm×300mm×400mm, heated with 0.85MPa steam for 40 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05MPa. A foamed molded body having an expansion ratio of 11.64 times (density 103 kg/m ^{3) was obtained.}

Example 2a

Except that it was pressed to the impregnation pressure of 1.3MPa, the impregnation amount of the blowing agent was 4.5% by weight, and the foaming time was set to 60 seconds, the same procedure as in Example 1a was carried out to obtain a volume multiple of 11.7 (volume density of 103kg / m ³⁾ of the expanded particles and the expansion ratio 13.3 times (density of 90kg / m ³⁾ molded foam.

Example 3a

Except that it was pressed to the impregnation pressure of 1.0 MPa, the impregnation amount of the blowing agent was 3.9% by weight, and the foaming time was 102 seconds, the same procedure as in Example 1a was carried out to obtain a volume multiple of 11.89 times (volume density of 101kg / m ³⁾ of the expanded particles and the expansion ratio 7.75 times (density 155kg / m ³⁾ molded foam.

Example 4a

Except for pressing into the impregnation pressure of 1.0 MPa, the impregnation amount of the foaming agent was 4.0% by weight, and the foaming time was 59 seconds, the same procedure as in Example 1a was carried out to obtain a volume multiple of 5.5 (volume density of 218kg / m ³⁾ of the expanded particles and the expansion ratio 4.30 times (density 279kg / m ³⁾ molded foam.

Example 5a

Except for pressing in to the impregnation pressure of 1.5MPa, the impregnation amount of the foaming agent was set to 5.2% by weight, and Teijin's PANLITE Z-2601 (density 1.2×10 ³ kg/m ³ ) was used as the polycarbonate resin And, except that the foaming temperature was set to 145°C and the foaming time was set to 31 seconds, the system was carried out in the same manner as in Example 1a to obtain ^{expanded particles with a volume ratio of 10.4 times (bulk density 116kg/m 3} ) and hair A foamed molded body with a foam ratio of 10.25 times (density 117 kg/m ^{3 ).}

Example 6a

Except for press-fitting to an impregnation pressure of 1.3 MPa, the impregnation amount of the foaming agent was set to 4.5% by weight, and PANLITE Z-2601 manufactured by Teijin was used as the polycarbonate resin, and the foaming temperature was set to 145°C. Except that the foaming time was set to 32 seconds, it was performed in the same manner as in Example 1a to obtain ^{expanded particles with a volume ratio of 9.4 times (bulk density 128kg/m 3} ) and an expansion ratio of 9.64 times (density 125 kg/m ³ ).的foaming molded body.

Comparative example 1a

Except for pressing into the impregnation pressure of 4.0 MPa, the impregnation amount of the blowing agent was 9.5% by weight, and the foaming time was set to 32 seconds, the same procedure as in Example 1a was carried out to obtain a volume multiple of 9.91 times (volume density of 121kg / m ³⁾ of the expanded particles and the expansion ratio 6.83 times (density 176kg / m ³⁾ molded foam.

Comparative example 2a

Except that it was pressed into the impregnation pressure of 4.0MPa, the impregnation amount of the blowing agent was 9.5% by weight, and the foaming time was set to 32 seconds, the same procedure as in Example 1a was carried out to obtain a volume multiple of 7.95 times (volume density of 151kg / m ³⁾ of the expanded particles and the expansion ratio 4.65 times (density 258kg / m ³⁾ molded foam.

Comparative example 3a

Except for press-fitting to an impregnation pressure of 4.0 MPa, the impregnation amount of the foaming agent was set to 7.8% by weight, and PANLITE Z-2601 manufactured by Teijin was used as the polycarbonate resin, and the foaming temperature was set to 145°C. Except that the foaming time was 23 seconds, it was performed in the same manner as in Example 1a to obtain ^{expanded particles with a volume ratio of 6.4 times (bulk density 188kg/m 3} ) and an expansion ratio of 4.62 times (density 260 kg/m ³ )的foaming molded body.

The average bubble diameter C, volume multiple, bulk density, apparent multiple, apparent density D, bubble number density, and average bubble wall thickness of the primary expanded particles of Examples 1a to 6a and Comparative Examples 1a to 3a and hair The evaluations of the average cell diameter C, open cell ratio, expansion ratio, density D, cell density X, average cell wall thickness, bending test results, and compression test results of the foam formed body are shown in Table 1 and Table 2.

In addition, the cross-sections of the expanded particles and foamed molded articles of Examples 1a to 6a and Comparative Examples 1a to 3a are magnified from 30 to 600 times using a scanning electron microscope, and are shown in Figures 1 to 3.

[Table 1]

[Table 2]

From Table 1 and Table 2 described above, it is known that by setting the cell density X and the average cell wall thickness in a specific range, a foamed molded product with high mechanical strength can be obtained. Specifically, it is known that when comparing Examples 1a to 4a and Comparative Examples 1a to 2a that also use L1250Y as the polycarbonate resin, compared with the Comparative Example, the maximum per unit density in the bending test of the Example The point stress and the elastic modulus, and the elastic modulus per unit density in the compression test have been improved. Moreover, when comparing Examples 5a to 6a, which also use Z-2601 as the polycarbonate resin, and Comparative Example 3a, it is found that compared to the Comparative Example, the Example is the maximum point stress per unit density in the bending test. And the modulus of elasticity, the modulus of elasticity per unit density in the compression test has been improved.

In addition, from the first to third figures, it is known that the fusion between the expanded particles of the expanded molding system of Comparative Examples 1a to 3a is insufficient, and there are many gaps between the expanded particles, so the appearance is somewhat poor; In contrast, the foamed molded articles of Examples 1a to 6a have almost no gaps between the expanded particles, and have good appearance.

Example 1b

(Procedure for manufacturing resin particles)

The polycarbonate resin particles (PANLITE L-1250Y manufactured by Teijin Corporation, density 1.20×10 ³ kg/m ³ ) were dried at 120° C. for 4 hours. The obtained dried product was supplied to a uniaxial extruder with a diameter of 40 mm at a rate of 10 kg/hr per hour, and was melt-kneaded at 290°C. Next, it was extruded from the die hole (equipped with 4 nozzles with a diameter of 1.5 mm) of the die head (temperature: 290°C, inlet side resin pressure: 13 MPa) installed at the tip of the single-screw extruder to approximately 10°C. In the processing chamber of the cooling water, the rotating shaft of the rotating blade with 4 cutting blades is rotated at 5000 rpm to cut into granules, and the cooling water is used to cool the resin particles (average particle size) 1.4mm).

(Impregnation step)

After sealing 100 parts by weight of the above-mentioned resin particles in a pressure vessel and replacing the inside of the pressure vessel with carbon dioxide gas, the carbon dioxide gas was pressure-injected to an impregnation pressure of 2.0 MPa. After being allowed to stand in an environment of 20°C and the impregnation time of 24 hours has elapsed, it took 5 minutes to slowly depressurize the pressure vessel. In this way, the resin particles are impregnated with carbon dioxide gas to obtain expandable particles. In addition, the foaming agent impregnation amount at this time was 5.8% by weight.

(Foaming step)

After depressurization in the above impregnation step, the expandable particles were immediately taken out of the pressure vessel, and then stirred with water vapor at a foaming temperature of 142°C for 39 seconds. At the same time, the impregnated material was made by steam in a high-pressure foaming tank. Foaming. After foaming, it was dried using a jet dryer to obtain expanded particles. The bulk density of the obtained expanded particles measured by the above method was 109 kg/m ³ (volume ratio 11.05 times).

(Forming step)

After the obtained expanded particles were left at room temperature (23°C) for one day, sealed in a pressure vessel, and after replacing the inside of the pressure vessel with nitrogen, the nitrogen was pressure-injected to an impregnation pressure (gauge pressure) of 1.0 MPa. It was allowed to stand still in an environment of 20° C., and subjected to pressure maturation for 24 hours. After taking it out, it is filled into a molding mold of 30mm×300mm×400mm, heated with 0.85MPa steam for 40 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05MPa. A foamed molded body having an expansion ratio of 11.45 times (density 105 kg/m ^{3) was obtained.}

Example 2b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and hair Bubble shaped body.

Impregnation pressure: 1.7MPa

Foaming agent impregnation amount: 5.6% by weight

Foaming time: 42 seconds

Example 3b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Impregnation pressure: 1.5MPa

Foaming agent impregnation amount: 5.0% by weight

Foaming time: 48 seconds

Example 4b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Impregnation pressure: 1.3MPa

Foaming agent impregnation amount: 4.5% by weight

Weight% foaming time: 61 seconds

Example 5b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Impregnation pressure: 2.0MPa

Foaming agent impregnation amount: 5.8% by weight

Foaming temperature: 144℃

Foaming time: 22 seconds

Example 6b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Impregnation pressure: 2.0MPa

Foaming agent impregnation amount: 5.6% by weight

Foaming time: 8 seconds

Example 7b

Except the following conditions, it carried out similarly to Example 1b, and obtained expanded particle|grains.

Polycarbonate resin particles: PANLITE Z-2601 manufactured by Teijin Corporation (density 1.2×10 ³ kg/m ³ )

Impregnation pressure: 2.0MPa

Foaming agent impregnation amount: 5.3% by weight

Foaming temperature: 144℃

Foaming time: 21 seconds

In addition, the molding step was performed in the same manner as in Example 1b, except that nitrogen was pressure-injected until the impregnation pressure (gauge pressure) became 1.6 MPa to obtain a foamed molded body.

Example 8b

Except the following conditions, it carried out similarly to Example 1b, and obtained expanded particle|grains.

Polycarbonate resin particles: PANLITE K-1300Y manufactured by Teijin Corporation (density 1.2×10 ³ kg/m ³ )

Impregnation pressure: 2.0MPa

Foaming agent impregnation amount: 5.5% by weight

Foaming temperature: 148℃

Foaming time: 26 seconds

In addition, the molding step was performed in the same manner as in Example 1b, except that nitrogen was pressure-injected until the impregnation pressure (gauge pressure) became 1.6 MPa to obtain a foamed molded body.

Example 9b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Polycarbonate resin particles: WONDERLITE PC-110 manufactured by Chi Mei Corporation (density 1.2×10 ³ kg/m ³ )

Impregnation pressure: 2.0MPa

Foaming agent impregnation amount: 5.8% by weight

Foaming temperature: 139℃

Foaming time: 41 seconds

Comparative example 1b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Impregnation pressure: 4.0MPa

Foaming agent impregnation amount: 9.5% by weight

Foaming time: 8 seconds

Comparative example 2b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and hair Bubble shaped body.

Polycarbonate resin particles: Lexan153 manufactured by SABIC (density 1.2×10 ³ kg/m ³ )

Impregnation pressure: 4.0MPa

Foaming agent impregnation amount: 9.9% by weight

Foaming time: 10 seconds

Comparative example 3b

Except for the following conditions, the same procedure as in Example 1b was carried out to obtain expanded particles and expanded molded articles.

Impregnation pressure: 1.0MPa

Foaming agent impregnation amount: 3.5% by weight

Foaming time: 147 seconds

Various physical properties of the expanded particles and foamed molded articles of Examples 1b to 9b and Comparative Examples 1b to 3b are shown in Tables 3 to 6.

In addition, photographs of the cross-sections of the expanded particles and molded foams of Examples 1b to 9b and Comparative Examples 1b to 3b enlarged to 30 times to 600 times with a scanning electron microscope are shown in Figs. 4 to 6.

[table 3]

[Table 4]

[table 5]

[Table 6]

From Table 3 to Table 6 above, it is known that by setting the volume ratio and the average bubble diameter in a specific range, a foamed molded product with high mechanical strength can be obtained.

In addition, it can be seen from Figures 4 to 6 that the fusion of the foamed particles of the foamed molding system of Comparative Examples 1b to 3b is insufficient, and there are many gaps between the foamed particles, so the appearance is poor; Therefore, the foaming molding system of Examples 1b to 9b has almost no gaps between the expanded particles, and the appearance is good.

Example 1c

(Procedure for manufacturing resin particles)

The polycarbonate resin particles (PANLITE L-1250Y manufactured by Teijin Corporation, density 1.20×10 ³ kg/m ³ ) were dried at 120° C. for 4 hours. The obtained dried product was supplied to a uniaxial extruder with a diameter of 40 mm at a rate of 10 kg/hr per hour, and was melt-kneaded at 290°C. Next, it was extruded from the die hole (equipped with 4 nozzles with a diameter of 1.5 mm) of the die head (temperature: 290°C, inlet side resin pressure: 13 MPa) installed at the tip of the single-screw extruder to approximately 10°C. In the processing chamber of the cooling water, the rotating shaft of the rotating blade with 4 cutting blades is rotated at 5000 rpm to cut into granules, and the cooling water is used to cool them to produce resin particles (average particle size 1.4 mm).

(Impregnation step)

After sealing 100 parts by weight of the above-mentioned resin particles in a pressure vessel and replacing the inside of the pressure vessel with carbon dioxide gas, the carbon dioxide gas was pressure-injected to an impregnation pressure of 2.0 MPa. After being allowed to stand in an environment of 20°C and the impregnation time of 24 hours has elapsed, it took 5 minutes to slowly depressurize the pressure vessel. In this way, the resin particles are impregnated with carbon dioxide gas to obtain expandable particles.

(Foaming step)

After depressurization in the above impregnation step, the expandable particles were immediately taken out of the pressure vessel, and then stirred with steam at a foaming temperature of 136°C for 54 seconds. At the same time, the impregnated substance Foaming. After foaming, it was dried using a jet dryer to obtain expanded particles.

(Forming step)

The obtained expanded particles were left at room temperature (23°C) for one day, and then sealed in a pressure vessel, and after replacing the pressure vessel with nitrogen, nitrogen was pressured in to an impregnation pressure (gauge pressure) of 1.0 MPa. It was allowed to stand still in an environment of 20° C., and subjected to pressure maturation for 24 hours. After taking it out, fill it into a molding mold of 30mm×300mm×400mm, and add 0.85MPa water vapor. It is heated for 40 seconds, and then cooled until the maximum surface pressure of the foamed molded body is reduced to 0.05 MPa, thereby obtaining a foamed molded body having an expansion ratio of 14 times.

Example 2c

Except that the foaming time of the foaming step was set to 8 seconds and the expansion ratio of the foamed molded article was approximately 5 times, the same procedure as in Example 1c was carried out to obtain expanded particles and a foamed molded article.

Example 3c

Except for using polycarbonate resin particles (PANLITE Z-260 manufactured by Teijin, density 1.20×10 ³ kg/m ³ ), the foaming temperature in the foaming step was set to 144°C, and the foaming time was set to 31 seconds Except that the impregnation pressure (gauge pressure) of the molding step was set to 1.6 MPa, and the expansion ratio of the foamed molded product was set to about 10 times, the same procedure as in Example 1c was carried out to obtain expanded particles and foams. Formed body.

Example 4c

Except for using polycarbonate resin particles (Lexan 153 manufactured by SABIC, density 1.20×10 ³ kg/m ³ ), the foaming temperature in the foaming step is set to 141°C, and the foaming time is set to 59 seconds, and Except that the expansion ratio of the foamed molded article was about 12 times, the same procedure as in Example 1c was carried out to obtain expanded particles and a foamed molded article.

Example 5c

Except for using polycarbonate resin particles (Lexan 101R manufactured by SABIC, density 1.20×10 ³ kg/m ³ ), the foaming temperature in the foaming step is set to 139°C, and the foaming time is set to 28 seconds, and Except that the expansion ratio of the foamed molded article was approximately 13 times, the same procedure as in Example 1c was carried out to obtain expanded particles and a foamed molded article.

Example 6c

Except for using polycarbonate resin particles (PANLITE K-1300Y manufactured by Teijin, density 1.20×10 ³ kg/m ³ ), the foaming temperature in the foaming step was set to 148°C, and the foaming time was set to 26 seconds Except that the impregnation pressure (gauge pressure) of the molding step was set to 1.6 MPa, and the expansion ratio of the foamed molded product was set to about 11 times, the same procedure as in Example 1c was carried out to obtain expanded particles and expanded molding. body.

Example 7c

Except for using polycarbonate resin particles (WONDERLITE PC-110 manufactured by Chi Mei Corporation, density 1.20×10 ³ kg/m ³ ), the foaming temperature in the foaming step is set to 141°C, and the foaming time is set to 41 Second, except that the expansion ratio of the foamed molded article was set to approximately 12 times, the same procedure as in Example 1c was carried out to obtain expanded particles and a foamed molded article.

Example 8c

Except for using polycarbonate resin particles (PANLITE L-1250Y manufactured by Teijin, density 1.20×10 ³ kg/m ³ ), the foaming temperature in the foaming step was set to 136°C, and the foaming time was set to 39 seconds Except that the expansion ratio of the foamed molded article was approximately 11 times, the same procedure as in Example 1c was carried out to obtain expanded particles and a foamed molded article.

Comparative example 1c

Except for using polycarbonate resin particles (Lexan 153 manufactured by SABIC, density 1.20×10 ³ kg/m ³ ), the impregnation pressure of the impregnation step was set to 4.0 MPa, and immediately after the expandable particles were taken out, the mixture was mixed with 100 parts by weight of the polycarbonate resin is 0.3 parts by weight of calcium carbonate as an anti-blocking agent, and the foaming time of the foaming step is set to 120 seconds, and the steam pressure of 0.35 MPa is heated for 60 seconds in the forming step Except for the above, the same procedure as in Example 1c was carried out to obtain expanded beads and expanded molded articles.

Comparative example 2c

(1) Manufacturing of PET foamed particles

Polyethylene terephthalate (PET) resin (Mitsui PET SA-135 manufactured by Mitsui Chemicals Co., Ltd.) 95% by weight, polyethylene naphthalate (PEN) resin (Teonex TN8050SC manufactured by Teijin Co., Ltd.) 5% by weight, Air bubble regulator (PET-F40-1 manufactured by Terabo) 1.8% by weight and crosslinking agent (pyromellitic anhydride manufactured by Daicel) 0.24% by weight were supplied to a uniaxial extrusion with a diameter of 65 mm and an L/D ratio of 35 Machine, and melt-kneading at 290°C. Next, from the middle of the extruder, butane composed of 35% by weight of isobutane and 65% by weight of n-butane was pressed into 0.5 parts by weight relative to 100 parts by weight of the total amount of PET resin and PEN resin To the resin composition in a molten state, and make it uniformly dispersed in the resin composition. After doing so, the molten resin composition was cooled to 250°C at the tip of the extruder, and then the resin composition was extruded and foamed from each nozzle of the multi-nozzle die installed at the tip of the extruder.

(2) Manufacturing of foamed molded products

Prepare an in-mold foam molding machine equipped with molds (male mold and female mold). In the state where the male mold and the female mold are clamped, a rectangular parallelepiped cavity with an internal dimension of 300 mm in length × 400 mm in width × 30 mm in height is formed between the male and female molds.

Then, the expanded beads were filled into the mold with the 3mm die gap cracked, and water vapor was introduced from the master mold so that the cavity became 0.05 MPa (gauge pressure) for 30 seconds, and then the water vapor Introduce from the male mold to 0.05MPa (gauge pressure) in the mold cavity for 30 seconds, and then supply water vapor from the male and female molds to 0.1MPa (gauge pressure) in the mold cavity for 30 seconds. The expanded particles are heated, and the secondary expanded particles are foamed secondarily, and the secondary expanded particles are thermally fused and integrated with each other. After that, after stopping the introduction of water vapor into the mold cavity for 900 seconds (heat preservation step), Finally, cooling water is supplied into the mold cavity to cool the foamed molded body in the mold, and then the mold cavity is opened and the foamed molded body is taken out. At this time, the time (molding cycle time) required from the step of filling the expanded particles in the mold to obtaining the expanded molded body was 1200 seconds.

Comparative example 3c

100 parts by weight of ethylene-propylene random copolymer and 0.10 parts by weight of zinc borate powder (bubble regulator) are supplied to the extruder, and are heated, melted and kneaded to form the first molten resin for forming the core layer. At the same time, the ethylene-propylene random copolymer is supplied to another extruder, and heated, melted and kneaded to form a second molten resin for forming a coating layer.

Next, the first molten resin for forming the core layer and the second molten resin for forming the coating layer are supplied to the coextrusion die, in which the second molten resin is used to cover the strands of the first molten resin The second molten resin is laminated on the first molten resin in a surrounding manner.

Next, the laminated molten resin is extruded from the co-extrusion die into a strand shape, and cut so that the diameter becomes about 1 mm and the length becomes about 1.8 times the diameter, to obtain the average weight per particle It is 1.8 mg of multilayer resin particles.

The aforementioned multilayer resin particles are used and expanded particles are produced in the following manner.

Add 100 parts by weight (1000 g) of the aforementioned multilayer resin particles, 300 parts by weight of water, 0.05 parts by weight of sodium dodecylbenzene sulfonate (surfactant), 0.3 parts by weight of kaolin (dispersant), and carbon dioxide in a 5 liter autoclave. The gas (foaming agent) is heated to a temperature 5°C lower than the foaming temperature while stirring, and the temperature is kept at this temperature for 15 minutes. Next, the temperature is raised to the foaming temperature and kept at the same temperature for 15 minutes. Next, open one end of the autoclave and release the contents of the autoclave to atmospheric pressure to obtain expanded particles.

In addition, during the release of the multilayer resin particles from the autoclave, the pressure in the autoclave is maintained The carbon dioxide gas is supplied into the autoclave by maintaining the pressure in the autoclave just before the release, and the release is performed at the same time.

The obtained expanded particle was used and molded into an expanded particle molded body in the following manner. The molding machine uses a small-scale molding machine that can withstand a saturated water vapor pressure of 0.48MPa(G). In a mold with a molding space of 50mm×200mm×50mm, there is a gap (about 5mm) that is not completely closed. Filling is performed in the state of, and then the mold is completely closed and the air in the mold is vented with water vapor pressure, and then 0.42 MPa of water vapor is supplied into the mold to perform heating and molding. After heating and molding, the water is cooled until the surface pressure of the molded body in the mold becomes 0.03 gMPa, and then the foamed molded body is taken out from the mold and aged at 80° C. for 24 hours, and then cooled to room temperature.

Table 7 shows various physical properties of the foamed molded articles of Examples 1c to 8c and Comparative Examples 1c to 3c. In Table 7, PC refers to polycarbonate resin, PET refers to polyester resin, and PP refers to acrylic resin.

[Table 7]

From Table 7 above, it is known that the foam molding systems of Examples 1c to 8c can further suppress changes in mechanical strength even if the ambient temperature changes. On the other hand, it is known that the foamed molded articles of Comparative Examples 1c to 3c have large fluctuations, or they are melted or deformed.

Also, for the maximum point stress system of the bending test, the calculated stress change values at -40°C and 23°C are shown in Table 8. The stress change means [(maximum point stress in the bending test at -40°C)-(maximum point stress in the bending test at 23°C)] ÷ (maximum point stress in the bending test at 23°C).

[Table 8]

In addition, for the maximum point stress in the bending test, the calculated stress changes at 80°C and 23°C are shown in Table 9. The stress change means [(maximum point stress in a bending test at 23°C)-(maximum point stress in a bending test at 80°C)]÷(maximum point stress in a bending test at 23°C).

[Table 9]

It is also known from Table 8 and Table 9 that, compared with the foamed molded articles of Comparative Examples 1c to 3c, the foamed molded articles of Examples 1c to 8c can further suppress the change in mechanical strength even if the ambient temperature changes.

Claims (10)

An expanded particle that uses a polycarbonate resin as a base resin, wherein the aforementioned expanded particle has (i) 1.0×10 ⁶ particles/cm ³ or more and less than 1.0×10 ^{8 particles} /cm ³ bubble density X[The bubble density X is calculated according to the following formula: bubble density X=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ } where , C means the average bubble diameter (μm), ρ means the density of the polycarbonate resin (kg/m ³ ), D means the apparent density of the expanded particles (kg/m ³ )], ( ii) An average cell wall thickness of 1 to 15 μm, and (iii) an open cell rate of 0 to 10%; the average cell diameter is 20 to 200 μm, and the density of the polycarbonate resin is 1.0×10 ³ to 1.4×10 ³ kg/m ³ , the apparent density of the aforementioned expanded particles is 20 to 640 kg/m ³ , and the aforementioned average cell wall thickness is calculated by the following formula: average cell wall thickness (μm) = average cell diameter C(μm)×(1 /(1-(1/apparent multiple)) ^(1/3) -1) In the formula, the apparent multiple is calculated by accumulating the density of the polycarbonate resin (kg/m ³ ) from the reciprocal of the apparent density The aforementioned continuous bubble rate is calculated by the following formula: continuous bubble rate (%)=100×(EB)/E where E=A+(CD), A is the aforementioned hair that is to be placed in an empty container made of metal mesh The total weight (g) of the foam particles, B is the volume (cm ³ ) of the foamed particles as a whole, C is the weight (g) of the empty container made of gold mesh in the state immersed in water, and D is the weight (g) The combined weight (g) of the aforementioned metal mesh container and the total amount of the aforementioned expanded particles put into this metal mesh container in the state of, E is the apparent volume (cm ³ ) of the aforementioned expanded particles. An expanded particle that uses a polycarbonate resin as a base resin, wherein (i) the aforementioned expanded particle is based on dividing the average cell diameter of the aforementioned expanded particle by the volume of the aforementioned expanded particle When the multiplier, it has a value in the range of 2.5 to 12μm/time; (ii) the continuous cell rate of 0 to 10%; the aforementioned volume multiplier is the reciprocal of the volume density to calculate the density of the polycarbonate resin (kg/m ³ ), the volume ratio is 2 to 20 times, the average bubble diameter is 20 to 200 μm, the volume density is 12 to 600 kg/m ³ , and the continuous cell rate is calculated by the following formula: continuous cell rate (%) =100×(EB)/E In the formula, E=A+(CD), A is the total weight (g) of the aforementioned expanded particles to be placed in an empty container made of metal mesh, and B is the overall volume of the aforementioned expanded particles (cm ³ ), C is the weight (g) of the aforementioned empty container made of gold mesh in the state of being immersed in water, D is the container made of the aforementioned metal net in the state of being immersed in water and the metal mesh made into this state The combined weight (g) of the total amount of the aforementioned expanded particles in the container, E is the apparent volume (cm ³ ) of the aforementioned expanded particles. The expanded particles described in item 2 of the scope of patent application, wherein the aforementioned expanded particles show ^{a cell number density of 1.0×10 7} to 1.0×10 ⁹ cells/cm ³ ; the aforementioned cell number density is calculated by the following formula: Number density=(ρ/D-1)/{(4/3)‧π‧(C/10000/2) ³ } where C is the average bubble diameter (mm) and ρ is the density of polycarbonate resin (kg/m ³ ), D is the apparent density of the expanded particles (kg/m ³ ); the density of the aforementioned polycarbonate resin is 1.0×10 ³ to 1.4×10 ³ kg/m ³ , the aforementioned expanded particles The apparent density is 20 to 640kg/m ³ . A foamed molded product obtained from the foamed particles described in item 1 or 2 of the scope of patent application. A foamed molded product is a foamed molded product obtained from a plurality of foamed particles using a polycarbonate resin as a base resin, wherein the foamed particles have an open cell ratio of 0 to 10%; For the foam molding system, measure the maximum stress value of the 4-point bending test at each temperature of -40℃, 23℃, 80℃ and 140℃, and calculate the average value of the maximum stress of the above four points of the bending test. When the value, the variation rate of the maximum point stress of the 4-point bending test with respect to the average value is in the range of 0 to 50%; the continuous cell rate of the foamed particles is calculated by the following formula: continuous cell rate ( %)=100×(EB)/E In the formula, E=A+(CD), A is the total weight (g) of the aforementioned foamed particles to be placed in an empty container made of metal mesh, and B is the whole of the aforementioned foamed particles The volume (cm ³ ) of, C is the weight (g) of the aforementioned empty container made of gold net in the state of being immersed in water, D is the container made of the aforementioned metal net in the state of being immersed in water and the metal The combined weight (g) of the total amount of the aforementioned expanded particles in the mesh container, E is the apparent volume (cm ³ ) of the aforementioned expanded particles. The foamed molded article as described in item 5 of the scope of patent application, wherein the aforementioned foamed The molding system has an open cell rate of 0 to 50%; the open cell rate of the aforementioned foamed molded body is calculated by the following formula: open cell rate (%) = (apparent volume-volume measured with an air comparison hydrometer)/ Apparent volume×100. The foamed molded article described in item 5 of the scope of patent application, wherein the foaming molding system has a foaming multiple of 3 to 30 times; the foaming multiple is the reciprocal of the density of the polycarbonate resin. (kg/m ³ ), the density of the aforementioned polycarbonate resin is 1.0×10 ³ to 1.4×10 ³ kg/m ³ . The foamed molded article as described in claim 5, wherein the four-point value of the maximum point stress in the bending test is divided by the density of the foamed molded article to calculate 4 points for the foamed molded article. "Maximum point stress/density of bending test" and the average value of "Maximum point stress/density of bending test" of the aforementioned 4 points, the value of "Maximum point stress/density of bending test" of the aforementioned 4 points is relative to The aforementioned average rate of change is in the range of 0 to 50%. The foamed molded article described in claim 5, wherein the polycarbonate resin has an MFR of 1.0 to 15.0 g/10 min. The foamed molded article described in item 5 of the scope of the patent application, wherein the aforementioned "maximum point stress of the bending test" at -40°C is 0 to 0.88 relative to the aforementioned "maximum point stress of the bending test" at 23°C Changes within the range.

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