JPS60239237A - Composite material and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial Application Field The present invention relates to a fluororesin composite material having a fluororesin layer heated and fired on the surface of a rubber material, and a method for producing the same.

(2) Conventional technology Fluororesins, such as tetrafluoroethylene resin (hereinafter referred to as PTFE), tetrafluoroethylene-perfluorovinylether copolymer (hereinafter referred to as PFA), tetrafluoroethylene-hexafluoropropylene copolymer As is well known, FEP (hereinafter referred to as FEP) has excellent properties such as chemical resistance, heat resistance, electrical insulation, self-lubricating property, and non-adhesion, and is used in the industrial field.
Although it has a wide range of applications in daily life, these properties make it difficult to process. In particular, PTFE has a transition point at 327°C, and PFA has a melting point at 306°C, and both can exhibit the above-mentioned excellent characteristics only when heated above this temperature.

For this purpose, we have formed a PTFE or PFA layer on the surface of the rubber material, which improves the non-adhesiveness and chemical resistance of the rubber material itself.
Attempts have been made to improve solvent resistance and oil resistance, but P
When heating and baking TFE and PFA, even if highly heat-resistant rubber such as silicone rubber or fluorine comb is used, the rubber material itself decomposes and deteriorates, and in reality, PT is deposited on the surface of the rubber material.
A heat-sintered layer of FE' and PFA was formed, and there was no single one.

For this first step, in the past, a fired sheet, tube, sleeve, etc. of PTFES'PFA, etc. was first manufactured, then a rubber material was pasted, and P, TFE was placed inside the tube.

PFA was poured in, or a fired shrink tube of PFA or PTFE was created, and the shrink tube was placed over the surface of a rubber sheet, roll, rod, etc. and heat-shrinked. With these methods, there is a limit to how thin the layer of PTFE, PFA, etc. can be to reduce the price, and in terms of characteristics, the thick layer of PTFE and PF'A does not have the elasticity that is originally a characteristic of rubber materials. Furthermore, due to the non-adhesive nature of PTFE-PFA, it is extremely difficult to adhere to the surface of rubber materials. It is necessary to use a very complicated method of adhering the adhesive using a physical anchor effect and pasting it on top of the adhesive.Also, in order to improve the adhesiveness, the PTFE itself is made porous. A method of bonding a porous material and rubber has also been developed.

(3) Problems to be Solved by the Invention The present invention solves the above-mentioned problems that cannot be obtained by the conventional methods, but without impairing the elasticity of the rubber material. The aim is to form an extremely thin heat-sintered layer of fluororesin that is highly adhesive, releasable, corrosion resistant, and solvent resistant.

(4) Means for Solving the Problems The composite material of the present invention has a heat-sintered layer of fluororesin on the surface of the rubber material.

In the method for manufacturing the composite material described above, the surface of a rubber material is coated with a fluororesin, and then the fluororesin is heated and fired at a temperature of 400° C. or higher for a very short time.

(5) Effect The present invention uses unfired PTFE, PFA, and
FEP etc. are applied using methods such as laminating, dipping, and painting.
After coating, this PTFE, pFA: F
It is obtained by heating for a very short time at a temperature of 400° C. or higher, which is higher than the transition point or melting point of EP and is beyond conventional wisdom.

That is, conventionally, PTFE is usually fired at a temperature of 360°C to 380°C for 8 minutes or more.
).

Therefore, in the specialized instruction manual for fluororesin, it is stated that ``When compounding with fluororesin, the material to be coated is iron, stainless steel, aluminum, glass, etc., and the baking temperature (400
℃)" (Published by Daikin, POLYFLON Handbook, p. 73). With conventional existing technology, PTFE, PFA, and FEP can be baked at temperatures of 360 to 380 degrees Celsius, or at most 400 degrees Celsius. It was said that it was necessary to take a long time to bake the product.

The present invention surpasses such existing technology and somehow manages to process PTFE and PFA without applying heat to the rubber material.

This is possible because the idea of firing only the FED allows the product to pass through temperatures of over 4,000 degrees Celsius, and essentially over 500 degrees Celsius, which is unimaginable under conventional wisdom. Therefore, when analyzed structurally, the fluororesin is melted and fired by rapidly applying radiant heat as high as 500°C to the fluororesin surface, which is within the narrow temperature range in which fluororesin melts as previously thought. This seems to overturn the logic that the product will not be fired unless it is heated for a certain period of time.

In the manner described above, a composite material having a heat-sintered layer of PTFE, PFA, etc. on the rubber material is manufactured.
Depending on the temperature selection, materials made of butyl rubber, ethylene vinyl acetate copolymer, and acrylic rubber can all be used. In addition, the shape of the rubber material can be processed into various complicated shapes such as roll, sheet, tube, O-ring, and loft shapes. It can be processed into various materials such as fiber material, composite material with metal, glass, and aromatic polyamide, and is not limited to the shape or structure of the rubber material. In addition, rubber materials can be processed depending on the situation, such as applying fluorine treatment to the rubber material before vulcanization and post-vulcanization, or applying fluorine treatment to the rubber material after vulcanization. Treatments may include mechanical polishing, liquid honing, chemical surface treatment, and of course, no surface treatment, depending on the intended use and required characteristics.

Fluororesin coatings can also be applied to sheets, tubes, and rods by methods including aqueous dispersion, enamel dipping, painting, powder coating, and molding, extrusion, and rolling of fluororesin formulations containing liquid lubricants. This includes all products in which a rubber material is manufactured, crimped onto a rubber material as it is, the liquid lubricant is removed, the material is pasted together by crimping, etc., and the material is composited with a rubber material and then fired.

Therefore, the coating thickness of the fluororesin on the rubber material is 10 parts to 1
It is possible to freely select up to WW.

(6) Examples Example 1 Silicone rubber was bonded to a metal shaft, and the surface of the rubber roller, which had already been vulcanized and finished, with a diameter of 80 mm and a roll length of 600 mm, was polished with sand vapor #320, and then subjected to tetrafluorocarbonization. Approximately 18μ of ethylene resin aqueous dispersion (Asahi Glass AD-1)
After applying the coating to a thickness of
A tunnel furnace with a length of 0 mm and 2 gn was manufactured, and the roll was passed through the furnace for about 4 minutes while rotating slowly in the furnace.

As a result, it remains white and unfired until it passes through the furnace.
The tetrafluoroethylene resin becomes completely transparent and is fired.
The surface of the silicone rubber roll is covered with tetrafluoroethylene resin to obtain a composite roller of silicone rubber and tetrafluoroethylene resin. After that, the hardness of this rubber was measured, and the shear hardness was 50, which was exactly the same as the initial stage, and there was no rubber deterioration.

Example 2 PTFE fine powder (trade name: Polyflon F103, manufactured by Daikin Industries, Ltd.) was placed on one side of an unvulcanized fluororubber sheet with a thickness of 3s+m, a width of 150mm, and a length of 20.01111mm.
After blending 100 parts with 23 parts of naphtha oil, extrusion and pressure processing were carried out, and the sheet was rolled, dried and stretched to a thickness of 120μ with calendar rolls, and one sheet was heated to 310°C and placed in a gamma hot plate press. A pressure of about 3 Kf/cd was applied and the mixture was allowed to stand for 1 hour for heating and vulcanization.

As a result, one rubber plate with a PTFE sheet composite on one side was obtained.

However, the attached PTFE sheet was still in an unfired state.

The thus obtained rubber plate was passed under a radiant heat plate (50 m long) at a temperature of 530°C for about 4 minutes.

As a result, completely baked P was formed on one side of the fluororubber sheet.
A TFE sheet was attached to obtain an elastic sheet.

Example 3 An acrylic rubber string with a diameter of 10 mm was coated with powdered PFA (manufactured by DuPont) to a thickness of about 20 μm using a powder coating method.
After drying by heating at 20° C. for about 15 minutes, it was run at a speed of 20 m/min in a 1 m long furnace controlled at 900° C.

As a result, the PFA was translucent and milky white, and one composite material was obtained by placing the fired PFA around the rubber string.

When this material was subjected to a tensile test, it showed a tensile strength of 156 h/Cd and an elongation of 140%, which was almost the same as that of a single rubber string, indicating that it is an elastic composite material.

(7) Effects According to the manufacturing method of the present invention, PTFE
, has the non-adhesive properties, mold releasability, corrosion resistance, and solvent resistance of PFA, and can also form an extremely thin film layer, and can be manufactured at a lower cost.

In addition, the rubber and calcined PTFE, PF obtained from the ship of the present invention
Composite materials with A etc. can be sheet-shaped, roll-shaped, tube-shaped,
It can be formed into strips or any complex shape.

Additionally, gamma products processed into composite materials require chemical resistance, corrosion resistance, mold release resistance, and elasticity. 0 ring rubber roll,
It can be applied to rubber sheets, rubber belts, coated cables, etc. Furthermore, if fluororubber or silicone rubber is used as the rubber material, it can be applied to the above-mentioned products that are used at high temperatures within the range of their heat resistance.

[Brief explanation of the drawing]

The drawing is an enlarged cross-sectional view of the composite material of the present invention. 1...Rubber material, 2...Heat-sintered layer of fluororesin Patent applicant: I, Nis, T Co., Ltd. Agent: Kama 1)
Sentence 2

Claims (4)

[Claims] (1) A composite material having a heat-sintered layer of fluororesin on the surface of a rubber material. (2) The composite material according to claim 1, comprising any one of the above-mentioned com material, silicone rubber, fluorine rubber, ethylene vinyl acetate copolymer, butyl rubber, and acrylic rubber. (3) Claims in which the fluororesin comprises any one of 4. fluorinated ethylene resin, tetrafluorinated ethylene-perfluorovinyl ether copolymer, and tetrafluorinated ethylene-hexafluorinated propylene copolymer. Composite material according to item 1. (4) In a method for producing a composite material of a fluororesin and a rubber material, which is obtained by coating the surface of a rubber material with a fluororesin and then firing the fluororesin at a temperature equal to or higher than its melting point, the fluororesin is
A private selection method for composites of fluororesin and rubber materials, which is characterized by heating and firing at a temperature of 0°C or higher in an extremely short period of time.