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Preparation method of high-thermal-conductivity polytetrafluoroethylene composite membrane material

A polytetrafluoroethylene and composite film technology, which is applied in the preparation of high thermal conductivity tetrafluoroethylene composite films and the preparation of high thermal conductivity polytetrafluoroethylene composite films, can solve the influence of film quality, limited improvement of material thermal conductivity, and filler filling. problems such as low volume, to achieve the effect of improving production efficiency and automation level, excellent thermal conductivity and mechanical properties, and improving comprehensive performance

Active Publication Date: 2021-12-28
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Although the above studies have improved the thermal conductivity of polytetrafluoroethylene plates or sheets and other shaped products, these products are all processed by the traditional "powder metallurgy method". The preparation of the sheet does not involve the preparation of PTFE composite membrane materials. It is difficult to meet the application requirements of high-frequency circuits, 5G communications, and micro-sensors for materials that are increasingly lightweight, miniaturized, and thin. The compounding of thermally conductive fillers has limited improvement in the thermal conductivity of materials
[0005]The disadvantage of using traditional pure PTFE membrane material preparation method (pre-compression molding-sintering-turning film) to prepare PTFE filled high thermal conductivity composite membrane material is that the whole preparation The process goes through the process of blending, pre-pressing, sintering for 24 hours or more, the use of alloys, blank turning, film forming, shaping and winding. It is very cumbersome, energy-consuming, and any problem occurs Significant effect on film quality
For example, in the pre-press molding and sintering process of the billet, it is easy to cause uneven stress and heat transfer in the billet, resulting in poor uniformity of the film; Particles are easy to separate from the PTFE matrix, resulting in more defects in the film produced, resulting in greater internal stress, making the film unable to be formed or poor in performance
How to develop a new preparation method of PTFE-filled high thermal conductivity composite membrane material is particularly important to overcome the inherent shortcomings of cumbersome preparation process, poor film uniformity, low filler filling, and large internal stress of the product.

Method used

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  • Preparation method of high-thermal-conductivity polytetrafluoroethylene composite membrane material

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preparation example Construction

[0034] The invention provides a preparation method of a polytetrafluoroethylene composite film material with high thermal conductivity, which adopts the following steps:

[0035] (1) Preparation of function-enhanced thermally conductive filler: modify the thermally conductive filler with a silane coupling agent, and mix the two types of thermally conductive fillers, the skeleton thermally conductive filler and the enhanced thermally conductive filler, to obtain a functionally enhanced thermally conductive filler;

[0036] (2) Composite dispersion preparation: Mix PTFE concentrated dispersion, function-enhanced thermal conductivity filler, dispersant, modifier, stabilizer, activator, defoamer, stir evenly, and prepare a composite dispersion;

[0037] (3) Film coating: Coating the composite dispersion liquid prepared in step (2), and controlling the coating thickness to be between 20 and 500 microns, and then drying;

[0038](4) Film sintering and stretching: the dried film is s...

Embodiment 1

[0062] The weight fraction content of each component:

[0063] Component Component parts by mass

[0064] PTFE concentrated dispersion 100

[0065] Flake boron nitride 40

[0066] Silica powder 80

[0067] In the first step, use 0.5~2.0% of the filler mass as a silane coupling agent to modify the surface of boron nitride and silicon dioxide; in the second step, mix the filler with 2 parts of dispersant, 2 parts of Add PTFE concentrated dispersion liquid and mix uniformly to make composite dispersion liquid; the third step, use composite dispersion liquid to coat one deck thickness and be the coating of 50 μ m, at 60 Drying at ℃ for 15 minutes; step 4, sintering at 375 ℃ for 30 minutes, and stretching at a speed difference of 0.3 m / min between the two rollers; step 5, cutting and winding. A high thermal conductivity PTFE composite membrane with a filler filling content of 63.8wt% was prepared through the above steps.

[0068] The performance test of the film prepared in th...

Embodiment 2

[0070] The weight fraction content of each component:

[0071] Component Component parts by mass

[0072] PTFE concentrated dispersion 100

[0073] Acicular alumina 40

[0074] Silica powder 60

[0075] In the first step, use 0.5~2.0% of the mass of the filler to modify the surface of aluminum nitride and silicon dioxide; in the second step, mix the filler with 2 parts of dispersant, 2 parts of Add the polytetrafluoroethylene concentrated dispersion and mix uniformly to make a composite dispersion; the third step is to use the composite dispersion to coat a coating with a thickness of 50 μm, at 80 Drying at ℃ for 10 minutes; step 4, sintering at 380 ℃ for 35 minutes, stretching under the condition that the speed difference between the two rolls is 0.3m / min; step 5, cutting and winding. A high thermal conductivity PTFE composite membrane with a filler loading of 59.52wt% was prepared through the above steps.

[0076] The performance test of the film prepared in this exampl...

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Abstract

The invention provides a preparation method of a high-thermal-conductivity polytetrafluoroethylene composite film material. The preparation method comprises the following steps: preparing a function-enhanced thermal-conductivity filler, mixing polytetrafluoroethylene and the function-enhanced thermal-conductivity filler, preparing a composite dispersion liquid, coating a thin film, carrying out gradient sintering on the thin film, stretching to orientate the filler, and cutting and rolling the material. The high-thermal-conductivity tetrafluoroethylene composite film provided by the invention has the characteristics of good thermal conductivity, excellent mechanical properties, good dimensional stability and adjustable and controllable functions.

Description

technical field [0001] The invention belongs to the technical field of high-performance composite materials, and in particular relates to a method for preparing a high-thermal-conductivity tetrafluoroethylene composite film, and more specifically relates to a kind of thermally conductive filler with a large filling amount, good thermal conductivity, excellent mechanical properties, and good dimensional stability. The preparation method of the high thermal conductivity polytetrafluoroethylene composite film. Background technique [0002] Polytetrafluoroethylene (PTFE) is a polymer formed by the polymerization of monomer tetrafluoroethylene. PTFE has a unique molecular structure, so it has excellent dielectric properties, chemical stability, thermal stability, tribological properties and low temperature ductility. Products with different structures and functions are used in electronics, construction, national defense, aerospace, filtration, Textile and machinery industry has ...

Claims

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Application Information

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IPC IPC(8): C08L27/18C08K13/06C08K9/06C08K7/00C08K3/36C08K7/08C08K7/06C08K3/34C08K3/04C08K3/08C08J5/18C09K5/14B29C67/04B29C55/02
CPCC08J5/18C09K5/14B29C67/04B29C55/02C08J2327/18C08K13/06C08K9/06C08K7/00C08K3/36C08K7/08C08K7/06C08K3/34C08K3/041C08K2201/011C08K2003/0812C08K2201/003C08K2201/004Y02P20/10
Inventor 陈蓉刘治宇郭少云
Owner SICHUAN UNIV