JPS6351464B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reinforced polyamide resin molded article. More specifically, the present invention relates to a reinforced polyamide resin molded product that more effectively exhibits the toughness of polyamide resin and the rigidity of inorganic reinforcing material.

Conventionally, thermoplastic reinforced composites made by kneading thermoplastic resin with glass fiber, etc., have significantly improved heat resistance and mechanical properties compared to resin alone, and have been used in the automobile industry,
Widely used in the electrical industry, etc.

Particularly in the automobile industry, the use of resin for various functional parts is being considered as an alternative to cast iron and aluminum from the standpoint of energy and resource conservation.
There is a trend that the amount of reinforced composite materials used is increasing.

However, as the amount of polyamide used increases, the environment in which it is used has become harsher than before, and as a result, reinforced polyamide resin, which has excellent mechanical properties and heat resistance among reinforced composite materials, has attracted attention.

However, even the well-known reinforced polyamide resin still does not satisfy the performance requirements of functional parts, and there was a desire for a reinforced polyamide resin molded product with even higher strength, high elasticity, and elongation, that is, a reinforced polyamide resin molded product with a large amount of energy absorption. .

As a result of intensive study on this point, the present inventor found that by selecting the surface treatment agent for the inorganic reinforcing material to be kneaded with the polyamide resin based on a completely different idea from the conventional one, the result is a high strength and high strength that is not seen in conventional reinforced polyamide resin molded products. It was discovered that an elastic and extensible molded article can be obtained, leading to the present invention.

That is, the reinforced polyamide resin molded article of the present invention uses a composition formed by blending a rubber oligomer and a chain extender (crosslinking agent) as a surface treatment agent for an inorganic reinforcing material so that it itself can have a three-dimensional network structure. The molded product is added to a silane coupling agent, etc., and carefully considered to prevent it from curing during the composite process of polyamide resin and inorganic reinforcing material, and adjusted so that this curing reaction progresses during the injection molding process. That is.

A reinforced polyamide resin molded product having such a structure has a crosslinked rubber layer at the interface between the polyamide resin and the inorganic reinforcing material, and this allows it to react with the silane coupling agent etc. on the surface of the inorganic reinforcing material. By reacting with polyamide resin, it exhibits strong interfacial bonding and extensibility.

That is, the reinforced polyamide resin molded article of the present invention is
In a reinforced polyamide resin molded article having a certain shape and in which fibrous, flaky or powdery inorganic reinforcing material is almost uniformly dispersed in the polyamide resin,
The present invention is characterized in that a crosslinked rubber is chemically bonded and integrated between the inorganic reinforcing material and the polyamide resin.

Various well-known polyamide resins can be used as the polyamide resin that can be used in the composition of the present invention. for example,
Polymers of ε-caprolactam, aminocaproic acid, enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, α-piperidone, etc. and polycondensation of diamines such as hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and metaxylylene diamine with dicarboxylic acids such as adipic acid, terephthalic acid, isophthalic acid, sebacic acid, and dodecanedicarboxylic acid. Refers to the resulting polymer or copolymer. Specifically, nylon 4, 6, 7, 8, 9, 11, 12,
Examples include 6.6, 6.9, 6.10, 6.11, 6.12, etc. In addition to these polyamide resins, it may contain 50% by weight or less of other resins.

As the inorganic reinforcing material used in the present invention, fibers such as glass fibers, metal fibers, carbon fibers, and silicon carbide fibers, mica, vermiculite flakes, talc flakes, and powders such as clay and glass beads can be used. As the glass fiber, a commercially available roving type glass fiber can be used, and there is no particular restriction.

The rubber-like elastic body that constitutes the interface between the inorganic reinforcing material such as glass fiber and the polyamide resin, which is the most important element in the present invention, is composed of a liquid polymer having a functional group at the end and a chain extender. is commonly referred to as a telekeylic polymer.

Telekylic polymers include 1.4-polybutadiene, 1.4-polybutadiene-acrylonitrile, 1.4-polybutadiene-styrene, 1.2-polybutadiene-chloroprene, polysulfide, etc., and have functional groups such as carboxyl groups, epoxy groups, amino groups, and hydroxyl groups at both ends. The functional groups do not necessarily have to be the same on both ends, and those that suit the properties of the material are selected.

Furthermore, the chain extender mentioned in the present invention is, for example, glycidyl ether of glycol, bisphenol A
glycidyl ether, diepoxy compounds such as epoxy novolak, phenylbis[1-(2-methyl)-aziridinyl]phosphine oxide,
diaziridinyl compounds such as bis[1-(2-ethyl)-aziridinyl]sebacyic acid amide;
2.4 diamino-6 undecyl-1.3.5 triazine,
diamino compounds such as diaminodiphenyl sulfone and diaminodiphenylmethane; diisocyanate compounds such as prepolymers of toluidine isocyanate and hexamethylene diisocyanate;
Examples include dihydroxy compounds such as 1.4-butanediol, 2-ethylhexanediol, resorcinol, and bisphenol A.

The blending ratio of the inorganic reinforcing material in the present invention is as follows:
It can be used in an amount of 1 to 150 parts by weight, more preferably 10 to 50 parts by weight, based on 100 parts by weight of the polyamide resin. The blending ratio of the crosslinked rubber is in the range of 0.1 to 20 parts by weight, more preferably 0.5 to 5 parts by weight, per 100 parts by weight of the inorganic reinforcing material. Also,
The amount of the chain extender may be approximately the chemically equivalent amount determined from the functional groups of the telechelic polymer, and may be in generally known proportions.

In addition to the above-mentioned essential components, the reinforced polyamide resin molded article of the present invention contains coupling agents such as silane coupling agents and titanium coupling agents used for surface treatment of inorganic reinforcing materials, anti-aging agents, ultraviolet absorbers, and oxidizing agents. Inhibitors, flame retardants, pigments, etc. can be added depending on the purpose. In particular, a coupling agent such as a silane coupling agent is interposed between the inorganic reinforcing material and the crosslinked rubber, and greatly contributes to improving the mechanical strength of the molded article.

The method for producing the reinforced polyamide resin molded article of the present invention involves blending the above-mentioned composition raw materials for the molded article, kneading, mixing, heating and melting in a molding machine, injecting into a mold, and cooling to obtain a molded article. . Note that the composition raw materials for the crosslinked rubber are in an uncrosslinked state, that is, a telechelic polymer and a chain extender are blended.
The telechelic polymer and chain extender react with each other by kneading and heating in a molding machine, producing a crosslinked rubber having a three-dimensional network structure.

As for the composition raw material, it is preferable that the surface of the inorganic reinforcing material is coated with a rubber composition raw material in advance. When the inorganic reinforcing material is a roving-like fiber, its surface is coated with a rubber composition raw material consisting of a mixture of a telechelic polymer and a chain extender, and then a polyamide resin is further applied to the surface by the crosshead of an extrusion molding machine. The rods can be coated using a die and then shredded into pellets. In this case, the rubber composition raw material is heated with molten polyamide resin while passing through the crosshead die of an extrusion molding machine, but by making the heating time extremely short, the above rod-shaped body can be manufactured without crosslinking the rubber. can do. The pellets obtained by this method can be used as raw materials for injection molding.

When the inorganic reinforcing material is in the form of thin flakes or granules, the inorganic reinforcing material and rubber composition raw materials are mixed and granular pellets are made from only them. This is mixed with pellet-shaped polyamide resin to form a mixed pellet, which is used as a raw material for injection molding.

The raw material may be prepared by methods other than those described above. However, the raw material before being fed into the injection molding machine must have the above-mentioned raw material composition, and the rubber component must be uncrosslinked.

Examples are shown below.

Example 1 50 parts by weight of polybutadiene-acrylonitrile copolymer with 1.40 unterminated carboxyl groups (manufactured by Ube Industries, Ltd.)
CTBN1300×13), 50 parts by weight of glycidyl ether type epoxy (Epicote 828 manufactured by Ciel Chemical Co., Ltd.), and 0.1 part by weight of triphenylphosphine at 300 c.c.
Place in a glass reaction vessel and heat at 130℃3 in an oil bath.
The mixture was heated and stirred for an hour, and then degassed using a water jet pump for an hour. This produced a 1.4 polybutadiene-acrylonitrile copolymer having epoxy groups at the ends. A surface treatment solution was prepared by adding 2 parts by weight of diaminodiphenylsulfon as a chain extender (crosslinking agent) and 1000 parts by weight of methyl ethyl ketone as a solvent to 10 parts by weight of the obtained reaction product.

Next, 5 rovings with an average diameter of 13 μm and a bundled number of 800 fibers were spun using a silane coupling agent, lubricant, etc.
The book was continuously introduced into a stainless steel container containing the treatment solution prepared above and immersed for about 0.2 seconds, then squeezed with a ceramic roller and introduced into a drying oven to distill off the solvent methyl ethyl ketone. The treated roving, which remained tacky, was passed through a continuous crosshead die and coated with polyamide resin. The coating amount of the rubber component was 1 part by weight per 100 parts by weight of glass fiber. The extruder is set at a cylinder temperature of 260℃ and a crosshead die of 265℃, and the nylon 66 (Leona 1300S manufactured by Asahi Kasei) is extruded through the crosshead die.
The resin temperature was 260°C.

The time required for coating with a crosshead dye and rapid cooling was adjusted to 0.1 seconds or less to prevent a curing reaction.

The roving coated with nylon 66 was then cut into pellets.

This pellet is used as a molding raw material, and the cylinder temperature is
It was molded into a tensile test piece in accordance with ASTM standards using an injection molding machine under molding conditions of 270°C, mold temperature 80°C, and injection pressure 1000Kg/cm ² . Immediately after molding, it was placed in a desiccator filled with silica gel and kept in an absolutely dry state. The obtained molded article had a smooth surface with no discoloration and glass fibers were uniformly dispersed therein, and the glass fiber content determined by the combustion method was 30.1% by weight.

In order to examine the mechanical properties of this molded article, it was tested under tensile conditions of a chuck distance of 100 mm, a tensile speed of 10 mm/min, and a temperature of 23°C. As a result, the tensile strength of this compact is
1750Kg/cm ² , elongation at break 6.7%, tensile modulus 41000Kg/
It was warm in ^cm2 .

In addition, the average diameter used in Example 1 as a comparative example
A roving of 13 μm and 800 bundles was dried without the treatment of the present invention, introduced into a crosshead die, coated with nylon 66, and formed into a composite in the same manner as in Example 1 for molding evaluation. The appearance of the test piece was the same as in Example 1, it was smooth, and the glass fiber content was
It was 30.4wt%. The mechanical properties of this molded body are tensile strength 1710Kg/cm ² , elongation at break 4.5%, and tensile modulus.
It was 42000Kg/ ^cm2 .

Example 2 As a rubber oligomer, unterminated epoxy, carboxyl-based liquid chloroprene rubber (Denka Kagaku Co., Ltd.) was used as a rubber oligomer.
10 parts by weight of LCR-CE) and glycidyl ether type epoxy (Ciel Chemical Co., Ltd. Epicoat) as a chain extender.
834), 0.01 part by weight of benzyldimethylamine as a catalyst, and 1000 parts by weight of methyl ethyl ketone as a solvent to prepare a treatment liquid.

Next, a glass roving was treated with this treatment liquid in the same manner as in Example 1. The proportion of the coated rubber component was 1 part by weight per 100 parts by weight of glass fiber. Further, in the same manner as in Example 1, the glass roving was continuously passed through a crosshead die and coated with nylon 6 (Amilan 1001N manufactured by Toray Industries, Ltd.), rapidly cooled, and continuously cut into pellets. The cylinder temperature of the extruder used for coating was set at 240°C, and the temperature of the crosshead die was set at 245°.

Next, this pellet was used as a raw material and molded in the same manner as in Example 1. Molding was carried out at a cylinder temperature of 240°C, a mold temperature of 80°C, and an injection pressure of 1000 Kg/cm ² .

The obtained molded product had a smooth surface, no discoloration, and glass fibers were uniformly dispersed. The glass fiber content of this molded article was 30% by weight by the combustion method. The mechanical strength of this molded body is tensile strength.
1620Kg/cm ² , elongation at break 7.0%, tensile modulus 37000Kg/
It was warm in ^cm2 .

As a comparative example, the same glass roving was introduced into a crosshead die without being treated with the rubber solution, coated with the same nylon 6, and cut into pellets. Next, this pellet was used as a raw material and molded in the same manner as in this example. The appearance of this molded product was smooth and the glass fibers were evenly dispersed. The glass fiber content was 30.2% by weight, and the mechanical strength was 1,650 Kg/cm ² in tensile strength, 5.2% in elongation at break, and 39,000 Kg/cm ² in tensile modulus.

Claims (1)

[Scope of Claims] 1. A reinforced polyamide resin molded article having a certain shape and in which a fibrous, flaky, or powdery inorganic reinforcing material is almost uniformly dispersed in a polyamide resin, the inorganic reinforcing material and the polyamide resin A reinforced polyamide resin molded article characterized in that a cross-linked rubber is chemically bonded and integrated in between. 2. Reinforcement according to claim 1, wherein the inorganic reinforcing material is 1 to 150 parts by weight per 100 parts by weight of the polyamide resin, and the crosslinked rubber is 0.1 to 20 parts by weight per 100 parts by weight of the inorganic reinforcing material. Polyamide resin molded body. 3. The reinforced polyamide resin molded article according to claim 1, wherein the inorganic reinforcing material is glass fiber.