CN113845740A - Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material - Google Patents
Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material Download PDFInfo
- Publication number
- CN113845740A CN113845740A CN202010526794.0A CN202010526794A CN113845740A CN 113845740 A CN113845740 A CN 113845740A CN 202010526794 A CN202010526794 A CN 202010526794A CN 113845740 A CN113845740 A CN 113845740A
- Authority
- CN
- China
- Prior art keywords
- thermal
- conductivity
- filler
- mass
- conducting filler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
- B29C67/02—Moulding by agglomerating
- B29C67/04—Sintering
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/08—Materials not undergoing a change of physical state when used
- C09K5/14—Solid materials, e.g. powdery or granular
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08J2327/18—Homopolymers or copolymers of tetrafluoroethylene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K13/00—Use of mixtures of ingredients not covered by one single of the preceding main groups, each of these compounds being essential
- C08K13/06—Pretreated ingredients and ingredients covered by the main groups C08K3/00 - C08K7/00
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/08—Metals
- C08K2003/0812—Aluminium
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/002—Physical properties
- C08K2201/003—Additives being defined by their diameter
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/002—Physical properties
- C08K2201/004—Additives being defined by their length
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/011—Nanostructured additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/04—Carbon
- C08K3/041—Carbon nanotubes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
- C08K3/36—Silica
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K7/00—Use of ingredients characterised by shape
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K7/00—Use of ingredients characterised by shape
- C08K7/02—Fibres or whiskers
- C08K7/04—Fibres or whiskers inorganic
- C08K7/06—Elements
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K7/00—Use of ingredients characterised by shape
- C08K7/02—Fibres or whiskers
- C08K7/04—Fibres or whiskers inorganic
- C08K7/08—Oxygen-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
- C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
The invention provides a preparation method of a high-thermal-conductivity polytetrafluoroethylene composite membrane material, which is realized by the following steps: preparing a function-enhanced heat-conducting filler, mixing polytetrafluoroethylene and the function-enhanced heat-conducting filler, preparing a composite dispersion liquid, coating a film, performing gradient sintering on the film, stretching the film to orient the filler, cutting and rolling. The high-thermal-conductivity tetrafluoroethylene composite membrane provided by the invention has the characteristics of good thermal conductivity, excellent mechanical property, good dimensional stability and adjustable and controllable functions.
Description
Technical Field
The invention belongs to the technical field of high-performance composite materials, particularly relates to a preparation method of a high-thermal-conductivity polytetrafluoroethylene composite film, and more particularly relates to a preparation method of a high-thermal-conductivity polytetrafluoroethylene composite film with large filling amount of a thermal-conductivity filler, good thermal conductivity, excellent mechanical properties and good dimensional stability.
Background
Polytetrafluoroethylene (PTFE) is a polymer made from the polymerization of the monomer tetrafluoroethylene. PTFE has a unique molecular structure, so that the PTFE has excellent dielectric property, chemical stability, thermal stability, tribological property and low-temperature ductility, and products with different structures and functions are widely applied to the industries of electronics, buildings, national defense, aerospace, filtration, textiles and machinery. The PTFE film material can be widely applied to multilayer circuit boards, capacitors, filtering devices and the like. However, PTFE has the characteristics of low thermal conductivity, large linear expansion coefficient and easy cold flow, so that PTFE cannot meet the heat dissipation requirements of products with high heat productivity, such as a new generation of high-frequency circuit board and a microelectronic chip. Therefore, attention has been paid to the researchers and the industry to improve the thermal conductivity and dimensional stability of PTFE while maintaining its excellent properties.
The preparation method comprises the steps of mixing silane coupling agent modified graphene and polytetrafluoroethylene resin in a high-speed mixer, performing cold press molding by using a molding press, and sintering by using a sintering furnace to prepare the graphene modified PTFE composite plate, wherein the heat conductivity and the wear resistance of the polytetrafluoroethylene plate are improved, and the volume resistivity of the composite plate is reduced by a small margin. And (3) adding 5-60 wt% of copper powder into PTFE (polytetrafluoroethylene) by using a tappet relieving agent and the like to prepare a Cu/PTFE composite material, and pressing and sintering the Cu/PTFE composite material into a cylindrical sample. The test result shows that the heat-conducting property of the Cu/PTFE composite material is obviously improved. The carbon nano tube/PTFE composite sheet is prepared by adopting a powder metallurgy method, such as Zhu Lei Ning and the like, the heat conductivity of the composite sheet is improved compared with that of a pure PTFE sheet, and the heat conductivity has an activation amplification effect when the temperature is increased.
Although the research improves the thermal conductivity of products in shapes such as polytetrafluoroethylene plates or sheets, the products are prepared by the traditional powder metallurgy method, the preparation of PTFE composite film materials is not involved, the application requirements of high-frequency circuits, 5G communication, micro sensors and the like on increasingly lightweight, small and thin materials are difficult to meet, the compounding of different types and forms of thermal conductive fillers is not carried out, and the improvement of the thermal conductivity of the materials is limited.
The PTFE filled high heat conduction composite membrane material prepared by adopting the traditional preparation method of pure PTFE membrane material (prepressing molding-sintering-turning film forming) has the defects that the whole preparation process is subjected to the processes of blending, prepressing molding, sintering for 24 hours or more, turning and film forming of blanks, shaping, rolling and the like by adopting alloy, is very complicated, has high energy consumption, and has obvious influence on the membrane quality when problems occur in any link. For example, during the pre-pressing and sintering processes of the blank, the uneven transmission of stress and heat in the blank is easy to occur, resulting in poor uniformity of the produced film; in the process of turning film formation, the filler particles are easy to generate interface separation with the PTFE matrix due to the action of strong cutting force, so that the prepared film has more defects, generates larger internal stress, and can not be formed or has poor service performance. How to develop a new preparation method of a PTFE filled high thermal conductivity composite membrane material is important to overcome the inherent defects of complex preparation process, poor film uniformity, low filling amount of filler, large internal stress of products and the like.
Disclosure of Invention
In view of the above problems, the present invention aims to provide a preparation method of a high thermal conductivity polytetrafluoroethylene composite film material, which uses a polytetrafluoroethylene concentrated dispersion as a main raw material, compounds and mixes different types, forms and functions of thermal conductive fillers to prepare a function-enhanced thermal conductive filler, and compounds the polytetrafluoroethylene concentrated dispersion and the function-enhanced thermal conductive filler. The prepared high-thermal-conductivity polytetrafluoroethylene composite film material has the functions of high thermal conductivity, low thermal expansion coefficient, excellent mechanical property, adjustable function and the like. The technical basic principle of the invention is as follows: preparing functional reinforced heat-conducting filler by compounding the skeleton heat-conducting filler and the reinforced heat-conducting filler, wherein the fibrous, needle-shaped or flaky skeleton heat-conducting filler with larger average particle size and higher length-diameter ratio is mutually overlapped in a matrix to form an effective three-dimensional heat-conducting network; the reinforced heat-conducting filler is granular, spherical or spheroidal with relatively small average particle size and is filled in gaps between the framework heat-conducting filler and the matrix resin to form more lap joints, further improve a three-dimensional heat-conducting network and improve the heat-conducting property of the system; meanwhile, the PTFE colloidal particles can be mutually lapped and wound with the framework heat-conducting filler and keep good interface action with the reinforced heat-conducting filler, so that the mechanical property of the composite membrane is further improved, and the high-heat-conductivity polytetrafluoroethylene composite membrane material with excellent comprehensive performance is further prepared.
The technical scheme provided by the invention is as follows:
the invention provides a preparation method of a high-thermal-conductivity polytetrafluoroethylene composite film, which is realized by the following steps:
(1) preparing a functional reinforcing filler: modifying the heat-conducting filler by using a silane coupling agent, and mixing the skeleton heat-conducting filler and the reinforced heat-conducting filler to obtain a functional reinforced filler;
(2) preparing a composite dispersion liquid: mixing the PTFE concentrated dispersion liquid, the function-strengthening filler, the dispersing agent, the modifier, the stabilizer, the activator and the defoaming agent, and uniformly stirring to prepare a composite dispersion liquid;
(3) film coating: coating the composite dispersion liquid prepared in the step (2), controlling the coating thickness to be 20-500 microns, and then drying;
(4) film sintering and stretching: sintering the dried film in a four-stage gradient heating mode, and stretching the film by utilizing the speed difference between two rollers in the fourth stage sintering process;
(5) cutting and rolling: and cutting and rolling the prepared film according to the required size.
The function-reinforced heat-conducting filler in the step (1) is a composite filler formed by mixing a skeleton heat-conducting filler modified by a silane coupling agent and a reinforced heat-conducting filler.
Preferably, the framework heat-conducting filler is one or more of carbon nano tube, fibrous carbon powder, needle-shaped alumina, flaky boron nitride and flaky silicon carbide.
Preferably, the reinforced heat-conducting filler is one or more of spherical alumina, granular silicon carbide, silicon dioxide micropowder, copper powder, silver powder and aluminum powder.
Preferably, the mass of the skeleton heat-conducting filler accounts for 20-40% of the total mass of the function-reinforced heat-conducting filler, and the average particle size is as follows: 300nm to 2 μm.
Preferably, the mass of the reinforced heat-conducting filler accounts for 60-80% of the total mass of the function-reinforced heat-conducting filler, and the average particle size is as follows: 5nm to 200 nm.
Preferably, the silane coupling agent used in the step (1) is one or more of a vinyl silane coupling agent, an epoxy silane coupling agent, a phenyl silane coupling agent, an amino silane coupling agent and a fluorocarbon silane coupling agent.
Preferably, the added mass of the silane modifier is 0.5-2.0% of the mass of the filler.
The mass parts of the components in the step (2) are as follows: 100 parts of PTFE concentrated dispersion liquid, 30-300 parts of heat-conducting filler, 0-4 parts of dispersing agent, 0-4 parts of modifying agent, 0-4 parts of stabilizing agent, 0-4 parts of activating agent and 0-2 parts of defoaming agent.
Preferably, the solid content of the polytetrafluoroethylene in the PTFE concentrated dispersion liquid is 60wt%, and the particle size is 0.1-0.5 μm.
In the step (3), the coating thickness is 20 to 500 μm.
Preferably, the drying temperature is 40-80 ℃, and the drying time is 5-30 min.
Preferably, the gradient temperature in the step (4) is divided into four sections, wherein the temperature of the first section is 60-160 ℃, the temperature of the second section is 161-250 ℃, the temperature of the third section is 251-350 ℃, and the temperature of the fourth section is 351-390 ℃.
Preferably, the sintering time of the first three sections at the gradient temperature is 10-15 min, and the sintering time of the fourth section is 10-60 min. The speed difference between the two stretching rollers is 0.01-1.0 m/min.
And (5) cutting the steel strip in the step (5) and then winding the steel strip to the maximum width of 1.5 m.
Compared with the prior art for preparing the high-thermal-conductivity polytetrafluoroethylene composite membrane, the preparation method has the following outstanding advantages:
1. the defects that the traditional PTFE membrane material preparation process is complex (the sintering process is carried out by blending, prepressing and forming for 24 hours or more, the processes from alloy to blank turning, film forming, sizing, rolling and the like are adopted), the sintering time is long, the energy consumption is high and the like are overcome, the process is simple, the whole film forming time is greatly shortened, the production efficiency and the automation level of a production line can be improved, and the PTFE membrane material has great application potential.
2. The prepared high-thermal-conductivity polytetrafluoroethylene composite film has the advantages of uniform dispersion of the functional reinforced thermal-conductivity filler, good film size stability, good flexibility and uniform thickness, and simultaneously the thermal conductivity and mechanical properties of the composite film material are excellent, the reinforced thermal-conductivity filler can be selected from fillers with other functions of thermal conductivity, electric conductivity, wear resistance, insulation and the like, so that the composite film is endowed with more functionality, the comprehensive performance of the composite film can be further improved, and the application range of the composite film is expanded.
3. According to the invention, the dried film is sintered by adopting four-section gradient temperature, the micromolecule auxiliary agents with different decomposition temperatures are decomposed and removed by the gradient temperature, and in the fourth-section sintering process, the temperature reaches above the melting temperature of PTFE, molecular chains of PTFE particles stretch and entangle, so that the structural defect caused by auxiliary agent removal is filled, the adverse effect of the micromolecule auxiliary agents on the performance of the composite film is avoided, and the comprehensive performance of the film is improved.
4. According to the invention, the high-thermal-conductivity polytetrafluoroethylene composite membrane is stretched by utilizing the difference of the speeds between the two rollers in the sintering process, so that the PTFE and the filler particles are oriented to a certain degree, the crystallization of the PTFE is more perfect, and the structural defects of the composite membrane are further reduced. Therefore, the mechanical property and the heat conductivity of the composite film can be further improved.
Drawings
FIG. 1 is a flow chart of a process for preparing a high thermal conductivity polytetrafluoroethylene composite membrane.
Detailed Description
The invention provides a preparation method of a high-thermal-conductivity polytetrafluoroethylene composite membrane material, which comprises the following steps:
(1) preparing a function-reinforced heat-conducting filler: modifying the heat-conducting filler by using a silane coupling agent, and mixing the skeleton heat-conducting filler and the reinforced heat-conducting filler to obtain a function-reinforced heat-conducting filler;
(2) preparing a composite dispersion liquid: mixing the PTFE concentrated dispersion liquid, the function-reinforced heat-conducting filler, the dispersing agent, the modifier, the stabilizer, the activator and the defoaming agent, and uniformly stirring to prepare a composite dispersion liquid;
(3) film coating: coating the composite dispersion liquid prepared in the step (2), controlling the coating thickness to be 20-500 microns, and then drying;
(4) film sintering and stretching: sintering the dried film in a four-stage gradient heating mode, and stretching the film by utilizing the speed difference between two rollers in the fourth stage sintering process;
(5) cutting and rolling: and cutting and rolling the prepared film according to the required size.
In the invention, the function-enhancing heat-conducting filler is preferably a mixture of a skeleton heat-conducting filler and a reinforced heat-conducting filler.
In the invention, the framework heat-conducting filler is preferably one or more of carbon nano tube, fibrous carbon powder, acicular alumina, flaky boron nitride and flaky silicon carbide.
In the invention, the reinforced heat-conducting filler is preferably one or more of spherical alumina, granular silicon carbide, silicon dioxide micropowder, copper powder, silver powder and aluminum powder.
In the invention, the proportion of the mass of the skeleton heat-conducting filler in the total mass of the function-reinforced heat-conducting filler is preferably 20-40%, and the average particle size is preferably as follows: 300nm to 2 μm.
In the invention, the mass of the reinforced heat-conducting filler accounts for 60-80 wt% of the total mass of the functional reinforced heat-conducting filler, and the average particle size is preferably as follows: 5nm to 200nm, and more preferably 50nm to 150 nm.
In the invention, the composite dispersion liquid comprises the following components in parts by weight: 100 parts of PTFE concentrated dispersion liquid, 30-300 parts of function-reinforced heat-conducting filler, 0-4 parts of dispersing agent, 0-4 parts of modifying agent, 0-4 parts of stabilizing agent, 0-4 parts of activating agent and 0-2 parts of defoaming agent.
In the invention, the polytetrafluoroethylene dispersion liquid is a commercial product, the solid content of polytetrafluoroethylene is 60wt%, and the particle size is 0.1-0.5 μm.
In the present invention, the dispersant is preferably a high molecular block copolymer.
In the present invention, the active agent is preferably a nonionic surfactant having a polyethylene glycol group or a polyol structure.
In the present invention, the modifier is preferably a titanate coupling agent.
In the invention, the stabilizing agent is preferably organic fluoride ion and nano silicon titanium ion ligand.
In the invention, the leveling agent is preferably one or more of polyacrylic acid, carboxymethyl cellulose, an organic silicon leveling agent and a fluorocarbon compound.
In the present invention, the defoaming agent is preferably an aqueous defoaming agent.
In the present invention, the antioxidant is preferably a water-soluble antioxidant, and more preferably sodium sulfite and/or sodium thiosulfate.
In the present invention, the coating thickness is preferably 20 to 500 μm, and more preferably 50 to 100 μm.
In the invention, the drying temperature is preferably 40-80 ℃, and the drying time is preferably 5-30 min, and more preferably 10-20 min.
In the invention, the gradient temperature is preferably four stages, the temperature of the first stage is preferably 60-160 ℃, further preferably 150 ℃, the temperature of the second stage is preferably 161-250 ℃, further preferably 180 ℃, the temperature of the third stage is preferably 251-350 ℃, further preferably 220 ℃, and the temperature of the fourth stage is preferably 351-390 ℃, further preferably 380 ℃.
In the invention, the sintering time of the first three sections at the gradient temperature is preferably 10-15 min, and the sintering time of the fourth section is preferably 10-60 min.
In the invention, the speed difference between the two stretching rollers is preferably 0.01-1.0 m/min.
In the invention, the winding width after harvesting is 1.5m at most.
The preparation method of the high thermal conductivity polytetrafluoroethylene composite membrane provided by the present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the present invention.
Example 1
The weight fraction of each component is as follows:
the mass portions of the components
Polytetrafluoroethylene concentrated dispersion 100
Boron nitride flakes 40
Fine silica powder 80
Firstly, carrying out surface modification on boron nitride and silicon dioxide by using a silane coupling agent accounting for 0.5-2.0% of the mass of the filler; secondly, adding the filler, 2 parts of dispersing agent, 2 parts of active agent, 1 part of modifying agent, 2 parts of stabilizing agent and 1 part of defoaming agent into the polytetrafluoroethylene concentrated dispersion liquid, and uniformly mixing to prepare composite dispersion liquid; thirdly, coating a layer of coating with the thickness of 50 mu m by using the composite dispersion liquid, and drying for 15min at the temperature of 60 ℃; fourthly, sintering at 375 ℃ for 30min, and stretching at the speed difference of two rollers of 0.3 m/min; and fifthly, cutting and rolling. The high-thermal-conductivity PTFE composite membrane with the filler filling amount of 63.8wt% is prepared through the steps.
The film prepared in the embodiment is subjected to performance test, and the measured thermal conductivity is 6.7W/(m.K), the tensile strength is 27MPa, the elongation at break is 82%, the coefficient of linear expansion CTE (coefficient of expansion) within the range of 0-200 ℃ is less than or equal to 20ppm/K, the dielectric constant epsilon =2.35, the dielectric loss tan delta =0.0025, and the use temperature is more than or equal to 250 ℃. Therefore, the composite film prepared by the embodiment has good thermal conductivity, good mechanical property, stable size and excellent dielectric property, and can be used for producing and manufacturing parts of key parts such as 5G communication, fire control radar, communication satellites and the like.
Example 2
The weight fraction of each component is as follows:
the mass portions of the components
Polytetrafluoroethylene concentrated dispersion 100
Acicular alumina 40
Fine silica powder 60
Firstly, using a silane coupling agent accounting for 0.5-2.0% of the mass of the filler to carry out surface modification on aluminum nitride and silicon dioxide; secondly, adding the filler, 2 parts of dispersing agent, 2 parts of active agent, 1 part of modifying agent, 2 parts of stabilizing agent and 1 part of defoaming agent into the polytetrafluoroethylene concentrated dispersion liquid, and uniformly mixing to prepare composite dispersion liquid; thirdly, coating a layer of coating with the thickness of 50 mu m by using the composite dispersion liquid, and drying for 10min at the temperature of 80 ℃; fourthly, sintering at 380 ℃ for 35min, and stretching under the condition that the speed difference between two rollers is 0.3 m/min; and fifthly, cutting and rolling. The high-thermal-conductivity PTFE composite membrane with the filler filling amount of 59.52wt% is prepared through the steps.
The film prepared by the embodiment is subjected to performance test, and the measured thermal conductivity can reach 5.6W/(m.K), the coefficient of linear expansion CTE is less than or equal to 15ppm/K within the range of 0-200 ℃, and the volume wear rate is only 1.1 percent of that of pure PTFE. Therefore, the composite film prepared by the embodiment has high thermal conductivity and excellent wear resistance, and can be widely applied to the fields of mechanical industry, automobile industry, aerospace and the like.
Example 3
The weight fraction of each component is as follows:
the mass portions of the components
Polytetrafluoroethylene concentrated dispersion 100
Fibrous carbon powder 40
Granular silicon carbide 60
Firstly, using a silane coupling agent accounting for 0.5-2.0% of the mass of the filler to carry out surface modification on carbon powder; secondly, adding 3 parts of dispersing agent, 2 parts of active agent, 1 part of modifying agent, 2 parts of stabilizing agent and 1 part of defoaming agent into the polytetrafluoroethylene concentrated dispersion liquid, and uniformly mixing to prepare composite dispersion liquid; thirdly, coating a layer of coating with the thickness of 50 mu m by using the composite dispersion liquid, and drying for 7min at the temperature of 80 ℃; fourthly, sintering at 365 ℃ for 40min, and stretching at the speed difference of two rollers of 0.4 m/min; and fifthly, cutting and rolling. The high-thermal-conductivity PTFE composite membrane with the filler filling amount of 59.17wt% is prepared through the steps.
The film prepared in the embodiment is subjected to performance test, and the measured thermal conductivity is 7.4W/(m.K), the tensile strength is 35MPa, the elongation at break is 90%, the coefficient of linear expansion CTE (coefficient of expansion) within the range of 0-200 ℃ is less than or equal to 25 ppm/K, the dielectric constant epsilon =4.5, and the use temperature is more than or equal to 250 ℃. Therefore, the composite film prepared by the embodiment has excellent heat-conducting property, mechanical property and dimensional stability.
Example 4
The weight fraction of each component is as follows:
the mass portions of the components
Polytetrafluoroethylene concentrated dispersion 100
Carbon nanotube 10
Aluminum powder 50
Firstly, carrying out surface modification on a filler by using a silane coupling agent accounting for 0.5-2.0% of the mass of the filler; secondly, adding the filler, 2 parts of dispersing agent, 2 parts of active agent, 1 part of modifying agent, 3 parts of stabilizing agent and 1 part of defoaming agent into the polytetrafluoroethylene concentrated dispersion liquid, and uniformly mixing to prepare composite dispersion liquid; thirdly, coating a coating with the thickness of 50 mu m by using the composite dispersion liquid; fourthly, drying for 8min at 75 ℃; fourthly, sintering at 375 ℃ for 25min, and stretching at the speed difference of two rollers of 0.3 m/min; and fifthly, cutting and rolling. The high-thermal-conductivity PTFE composite membrane with the filler filling amount of 46.51wt% is prepared through the steps.
The film prepared by the embodiment is subjected to performance test, and the measured thermal conductivity is 8.7W/(m.K), the volume resistivity is less than or equal to 0.05 omega.cm, the tensile strength is 39MPa, the elongation at break is 101%, the coefficient of linear expansion CTE (coefficient of expansion) within the range of 0-200 ℃ is less than or equal to 20ppm/K, and the service temperature is more than or equal to 250 ℃. Therefore, the composite film prepared by the embodiment has excellent heat-conducting property, good electric conductivity, stable size and certain flexibility, can be used as a substrate of a flexible circuit board, and has great application potential in the fields of intelligent wearing, microelectronic apparatuses and the like.
Claims (8)
1. A preparation method of a high-thermal-conductivity polytetrafluoroethylene composite film material is characterized by comprising the following steps:
(1) preparing a function-reinforced heat-conducting filler: modifying the heat-conducting filler by using a silane coupling agent, and mixing the skeleton heat-conducting filler and the reinforced heat-conducting filler to obtain a function-reinforced heat-conducting filler;
(2) preparing a PTFE composite dispersion liquid: mixing the PTFE concentrated dispersion liquid, the function-reinforced heat-conducting filler, the dispersing agent, the modifier, the stabilizer, the activator and the defoaming agent, and uniformly stirring to prepare a PTFE composite dispersion liquid;
(3) film coating: coating the composite dispersion liquid prepared in the step (2), controlling the coating thickness to be 20-500 microns, and then drying;
(4) film sintering and stretching: sintering the dried film in a four-stage gradient heating mode, and stretching the film by utilizing the speed difference between two rollers in the fourth stage sintering process;
(5) cutting and rolling: and cutting and rolling the prepared film according to the required size.
2. The preparation method of the high thermal conductivity polytetrafluoroethylene composite film material according to claim 1, wherein the function-enhancing thermal conductive filler in step (1) is a mixture of a skeleton thermal conductive filler and a reinforcing thermal conductive filler, and the skeleton thermal conductive filler is one or more of carbon nanotubes, fibrous carbon powder, needle-like alumina, flaky boron nitride and flaky silicon carbide; the reinforced heat-conducting filler is one or more of spherical alumina, granular silicon carbide, silicon dioxide micro powder, copper powder, silver powder and aluminum powder.
3. The preparation method of the high-thermal-conductivity polytetrafluoroethylene composite film material according to claim 1, wherein in the step (1), the mass of the skeleton heat-conducting filler accounts for 20-40% of the total mass of the function-reinforcing heat-conducting filler, and the average particle size is 300 nm-2 μm; the mass of the reinforced heat-conducting filler accounts for 60-80% of the total mass of the function-reinforced heat-conducting filler, and the average particle size is 5 nm-200 nm.
4. The preparation method of the high-thermal-conductivity polytetrafluoroethylene composite film material according to claim 1, wherein the silane coupling agent adopted in the step (1) is one or more of a vinyl silane coupling agent, an epoxy silane coupling agent, a phenyl silane coupling agent, an aminosilane coupling agent and a fluorocarbon silane coupling agent, and the addition amount is 0.5-2.0% of the mass of the filler.
5. The preparation method of the high-thermal-conductivity polytetrafluoroethylene composite film material as claimed in claim 1, wherein the composite dispersion liquid in step (2) is prepared from 100 parts by mass of a PTFE concentrated dispersion liquid, 30-300 parts by mass of a function-enhanced thermal-conductive filler, 0-4 parts by mass of a dispersant, 0-4 parts by mass of a modifier, 0-4 parts by mass of a stabilizer, 0-4 parts by mass of an active agent and 0-2 parts by mass of a defoaming agent, and the addition sequence is as follows: PTFE concentrated dispersion liquid, a function-reinforced heat-conducting filler, an active agent, a modifier, a dispersant, a stabilizer and a defoaming agent.
6. The preparation method of the high-thermal-conductivity polytetrafluoroethylene composite film material as claimed in claim 1, wherein the drying temperature in step (3) is 40-80 ℃ and the drying time is 5-30 min.
7. The preparation method of the high-thermal-conductivity polytetrafluoroethylene composite film material according to claim 1, wherein the gradient temperature in the step (4) is divided into four sections, the temperature of the first section is 60-160 ℃, the temperature of the second section is 161-250 ℃, the temperature of the third section is 251-350 ℃, the temperature of the fourth section is 351-390 ℃, the sintering time of the first three sections is 10-15 min, the sintering time of the fourth section is 10-60 min, and the speed difference between two stretching rollers is 0.01-1.0 m/min.
8. The preparation method of the high thermal conductivity polytetrafluoroethylene composite film material as claimed in claim 1, wherein the winding width after cutting in step (5) is up to 1.5 m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010526794.0A CN113845740B (en) | 2020-06-11 | 2020-06-11 | Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010526794.0A CN113845740B (en) | 2020-06-11 | 2020-06-11 | Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113845740A true CN113845740A (en) | 2021-12-28 |
| CN113845740B CN113845740B (en) | 2023-03-21 |
Family
ID=78972015
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010526794.0A Active CN113845740B (en) | 2020-06-11 | 2020-06-11 | Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113845740B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114181482A (en) * | 2021-11-29 | 2022-03-15 | 山东东岳高分子材料有限公司 | Filled polytetrafluoroethylene dispersion resin and preparation method thereof |
| CN114874485A (en) * | 2022-06-22 | 2022-08-09 | 山东大学 | High-thermal-conductivity polytetrafluoroethylene nanofiber membrane and manufacturing process thereof |
| CN116333368A (en) * | 2023-05-31 | 2023-06-27 | 天津理工大学 | Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013209542A (en) * | 2012-03-30 | 2013-10-10 | Nippon Valqua Ind Ltd | Thermally conductive fluororesin film |
| CN103435895A (en) * | 2013-09-11 | 2013-12-11 | 四川大学 | Method for preparing insulating high-thermal-conductivity composite material |
| CN104175686A (en) * | 2014-08-01 | 2014-12-03 | 广东生益科技股份有限公司 | Preparation method of polytetrafluoroethylene (PTFE) composite dielectric substrate |
| CN105175842A (en) * | 2015-09-18 | 2015-12-23 | 四川大学 | Polymer-based insulating and heat conducting composite material with efficient heat conductivity and excellent mechanical properties |
| CN107639906A (en) * | 2017-07-17 | 2018-01-30 | 常州中英科技股份有限公司 | A kind of high heat conduction fluorine resin base prepreg and its copper-clad plate of preparation |
| CN108656683A (en) * | 2018-04-16 | 2018-10-16 | 常州中英科技股份有限公司 | A kind of fluorine resin base copper-clad plate of high-k and preparation method thereof |
| CN109328135A (en) * | 2016-06-17 | 2019-02-12 | 忍冬电子株式会社 | Thermally conductive film piece and product comprising it |
| CN110343315A (en) * | 2019-07-04 | 2019-10-18 | 江苏新奥碳纳米材料应用技术研究院有限公司 | Containing Monodispersed, polymer bond's film of highly oriented graphene and preparation method thereof |
-
2020
- 2020-06-11 CN CN202010526794.0A patent/CN113845740B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013209542A (en) * | 2012-03-30 | 2013-10-10 | Nippon Valqua Ind Ltd | Thermally conductive fluororesin film |
| CN103435895A (en) * | 2013-09-11 | 2013-12-11 | 四川大学 | Method for preparing insulating high-thermal-conductivity composite material |
| CN104175686A (en) * | 2014-08-01 | 2014-12-03 | 广东生益科技股份有限公司 | Preparation method of polytetrafluoroethylene (PTFE) composite dielectric substrate |
| CN105175842A (en) * | 2015-09-18 | 2015-12-23 | 四川大学 | Polymer-based insulating and heat conducting composite material with efficient heat conductivity and excellent mechanical properties |
| CN109328135A (en) * | 2016-06-17 | 2019-02-12 | 忍冬电子株式会社 | Thermally conductive film piece and product comprising it |
| CN107639906A (en) * | 2017-07-17 | 2018-01-30 | 常州中英科技股份有限公司 | A kind of high heat conduction fluorine resin base prepreg and its copper-clad plate of preparation |
| CN108656683A (en) * | 2018-04-16 | 2018-10-16 | 常州中英科技股份有限公司 | A kind of fluorine resin base copper-clad plate of high-k and preparation method thereof |
| CN110343315A (en) * | 2019-07-04 | 2019-10-18 | 江苏新奥碳纳米材料应用技术研究院有限公司 | Containing Monodispersed, polymer bond's film of highly oriented graphene and preparation method thereof |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114181482A (en) * | 2021-11-29 | 2022-03-15 | 山东东岳高分子材料有限公司 | Filled polytetrafluoroethylene dispersion resin and preparation method thereof |
| CN114874485A (en) * | 2022-06-22 | 2022-08-09 | 山东大学 | High-thermal-conductivity polytetrafluoroethylene nanofiber membrane and manufacturing process thereof |
| CN114874485B (en) * | 2022-06-22 | 2023-03-10 | 山东大学 | High-thermal-conductivity polytetrafluoroethylene nanofiber membrane and manufacturing process thereof |
| CN116333368A (en) * | 2023-05-31 | 2023-06-27 | 天津理工大学 | Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof |
| CN116333368B (en) * | 2023-05-31 | 2023-08-08 | 天津理工大学 | Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113845740B (en) | 2023-03-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113845740B (en) | Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material | |
| CN109181178B (en) | Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material | |
| KR101575944B1 (en) | Composite material, high-frequency circuit baseboard made therefrom and production method thereof | |
| US7998367B2 (en) | Metal-carbon nanotube composites for enhanced thermal conductivity for demanding or critical applications | |
| CN108943779B (en) | Preparation method of polytetrafluoroethylene composite film material with high filler filling amount | |
| CN102181168B (en) | Polymer matrix composite material and production method of polymer matrix composite material | |
| CN109161167B (en) | Boron nitride-silver/epoxy resin composite material and preparation method and application thereof | |
| CN110734614A (en) | PTFE (Polytetrafluoroethylene) substrate material for high-frequency copper-clad plate and preparation method thereof | |
| CN112679890B (en) | Flexible copper-clad plate base material, preparation method and application thereof, and circuit board | |
| Yuan et al. | Effects of perfluorooctyltriethoxysilane coupling agent on the properties of silica filled PTFE composites | |
| CN115891137A (en) | Method for 3D printing of electromagnetic shielding part with porous structure on basis of polyolefin elastomer | |
| Yuan et al. | Effects of compound coupling agents on the properties of PTFE/SiO 2 microwave composites | |
| CN112551945A (en) | Modified PTFE composite dielectric material with high thermal conductivity and low dielectric constant and preparation method thereof | |
| CN111621253A (en) | Graphite-based high-strength heat-conducting epoxy resin adhesive and preparation method thereof | |
| CN115594512B (en) | PTFE-ceramic slurry for high-frequency microwaves and sintering film thereof, and preparation method and application thereof | |
| CN113306227B (en) | High-frequency ultralow-dielectric-loss microwave ceramic copper-clad plate and preparation method thereof | |
| CN107686635B (en) | Preparation method of graphene/solid epoxy resin high-thermal-conductivity composite material | |
| CN115216151B (en) | Construction method of polyimide film heat conduction channel | |
| CN113337077B (en) | High-thermal-conductivity electromagnetic shielding polyether-ether-ketone composite material with isolation structure and preparation method and application thereof | |
| CN114409866B (en) | Preparation method of polymer-based damping composite material with local directional arrangement structure | |
| CN112812476B (en) | Polytetrafluoroethylene composite material and preparation method and application thereof | |
| CN114835987B (en) | Micron-sized surface porous SiO 2 Base microwave composite medium substrate and preparation method thereof | |
| CN114644846A (en) | Fluorine-containing polymer emulsion copper-clad plate and preparation method thereof | |
| Zhang et al. | New method to prepare corona resistant polyimide composite film | |
| CN114369266A (en) | Composite material sheet for microwave circuit substrate, preparation method thereof and microwave circuit substrate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |