JP2003238714A - Method for producing sealing medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a sealing medium of a rubber-like elastic material coated with a poly-p-xylylene film which has a low carbon dioxide gas permeability and does not cause the peeling of the film even when subjected to flex deformation. <P>SOLUTION: The method for producing the sealing medium having the film of the poly-p-xylylene, a polymonochloro-p-xylylene or a polydichloro-p-xylylene formed on the surface of the rubber-like elastic material composed of an NBR, or the like, comprises treating the surface of the rubber-like elastic material with an alkali detergent, then subjecting the resulting surface to adhesion treatment with a silane coupling agent, and forming the poly-p-exylylene film on the obtained surface by the gas phase deposition polymerization method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sealing material having excellent permeation resistance to natural refrigerants used as refrigerants for compressors of air conditioners or refrigerators, such as ammonia, hydrocarbons, especially carbon dioxide. .

[0002]

2. Description of the Related Art Conventionally, Freon gas is generally used as a refrigerant used in refrigerators and car air conditioners. Due to the problems of ozone layer depletion and environmental destruction such as global warming, the development of new refrigerants for these CFCs has been advanced recently. Although ammonia, hydrocarbons, carbon dioxide, etc. are candidates, carbon dioxide is the most promising from the viewpoint of safety.

Conventionally, in the case of CFC gas refrigerant, acrylonitrile-butadiene rubber (NBR), hydrogenated NB
A rubber elastic body for a sealing material such as R or EPDM is used. When these rubber elastic bodies are used as a carbon dioxide sealing material, carbon dioxide gas permeates the rubber elastic body,
As a result, the rubber elastic body is swollen and foamed. In order to reduce the gas permeability of the sealing material, there is generally a method of adding a non-reinforcing filler such as mica or graphite, but this method tends to cause foaming of the rubber elastic body.

Also, NBR, hydrogenated NBR or EP
There is also a method of mixing a material having low carbon dioxide gas permeability with DM. However, these materials generally have poor compatibility with NBR, hydrogenated NBR or EPDM, and the mixture of these materials has a problem of poor workability.

Further, there is a method of using a vinylidene fluoride resin, which is a material having a low carbon dioxide permeability, but it is inferior to a rubber material in processability and flexibility, and when used as a sealing material, the deformation followability is poor and the sealing medium becomes This will cause a leak. Moreover, when the sealing material made of vinylidene fluoride resin is attached to a member that has been splined, it is likely to be damaged by the spline and the sealing performance cannot be maintained.

In this technical field, there are the following prior arts. Japanese Patent Laid-Open No. 11-193332 discloses that
Fluorine rubber type thermoplastic elastomer with 100 nm particle size
The following molding materials for carbon dioxide have been disclosed, which contain the following reinforcing fillers. Further, Japanese Patent Application Laid-Open No. 11-172231 discloses a carbon dioxide gas sealing material in which the surface layer of a fluororubber sealing material is formed of a fluoroplastic elastomer. Further, Japanese Patent Laid-Open No. 2001-280509 discloses a ring-shaped gasket body made of a vulcanized product of a main rubber compound based on NBR rubber, and a vulcanized product of a rubber elastic body based on fluorine rubber. , A gasket having a barrier layer formed on the surface thereof is disclosed. Further, Japanese Patent Laid-Open No. 2001-182837 discloses a rubber component for fuel seal, which is characterized in that fluorosilicone rubber is coated with nylon.

Further, Japanese Patent Laid-Open No. 6-313059 discloses a technique of forming a polyparaxylylene film by a vapor phase vapor deposition polymerization method in order to improve gas permeability and friction coefficient of silicone rubber. In addition, Japanese Patent Laid-Open No. 2000-485
No. 52 discloses a technique of coating a hard disk component with polyparaxylylene or a derivative thereof. Further, Japanese Patent Laid-Open No. 2001-240846 discloses a technique of coating rubber packing with polyparaxylylene or its derivative.

[0008] These prior arts do not have a sufficient sealing property as a carbon dioxide sealing material, and in particular, a rubber elastic sealing material having a film formed of polyparaxylylene has a film Since the adhesion of the rubber elastic body is insufficient, the coating cannot follow the deformation of the rubber elastic body when repeatedly subjected to bending deformation, and the coating peels off.

[0009]

SUMMARY OF THE INVENTION The present invention is a rubber elastic sealing material coated with polyparaxylylene, which has low carbon dioxide gas permeability and does not cause peeling of the coating film even when subjected to bending deformation. A method for manufacturing a material is provided.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a sealing material in which a polyparaxylylene film is formed on the surface of a rubber elastic body, after the surface of the rubber elastic body is treated with an alkaline cleaning agent, and then a silane cup is used. The method for producing a sealing material is characterized in that the polyparaxylylene film is adhered with a ring agent and a polyparaxylylene film is formed by a vapor deposition polymerization method.

In the method for producing the sealing material, it is preferable that the surface of the rubber elastic body is etched by corona discharge after the treatment with the alkaline cleaner.

In the method for producing a sealing material of the present invention, the polyparaxylylene is preferably polyparaxylylene, polymonochloroparaxylylene or polydichloroparaxylylene. Further, the rubber elastic body is acrylonitrile-butadiene rubber (NBR) or hydrogenated acrylonitrile-butadiene rubber (hydrogenated NBR).
Is preferred.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a method for producing a sealing material in which a polyparaxylylene film is formed on the surface of a rubber elastic body.

(Rubber Elastic Body) In the present invention, the rubber elastic body contains acrylonitrile-butadiene rubber (NBR), hydrogenated NBR or EPDM, a fluorine-based rubber, a fluorine-based thermoplastic elastomer, and an epichlorohydrin-based rubber as a rubber component. A single rubber or a mixture of these may be used, especially acrylonitrile-butadiene rubber (NB
R), hydrogenated NBR or EPDM-based systems are preferred. A diene rubber such as polyisoprene, polybutadiene, or styrene-butadiene copolymer rubber may be mixed in the rubber component in an amount of 30% by mass or less.

Acrylonitrile-butadiene rubber (NB
R) is low nitrile (acrylonitrile content 24
Mass% to high nitrile (acrylonitrile content 36-
42% by mass) can be used. Further, in order to maintain the oil resistance of NBR and improve the aging resistance, a hydrogenated NBR in which the cyano group of the side chain of NBR is left as it is and the double bond portion of carbon and carbon is selectively hydrogenated can also be used.

Examples of trade names of NBR include Nipol manufactured by Nippon Zeon Co., JSR manufactured by Nippon Synthetic Rubber Co., Ltd., and Perbunan N manufactured by Buyer AG. In addition, as trade names of hydrogenated NBR, 0029, 1020, 10 of Nippon Zeon Co., Ltd.
10 and Bayer 1706, 17071746 and the like.

The fluorinated rubber is a highly fluorinated elastic copolymer such as vinylidene fluoride and hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl. One or more copolymers of fluoride, perfluoro (methyl vinyl ether), perfluoro (propyl vinyl ether) and the like are used.

As the fluorine-based thermoplastic elastomer, two types, block type and graft type, can be used. A block type fluorine-based thermoplastic elastomer is a thermal polymer obtained by block-bonding a fluororubber component (soft segment) and a fluororesin component (hard segment) by utilizing telomerization by an iodine compound in radical polymerization of a fluoromonomer. It is a plastic elastomer. Then, the structure is such that the soft segment is reinforced by the hard segment in the molecule by chemical bonding.

The thermoplastic elastomer exhibits the properties of rubber at high temperature and the properties of resin at low temperature, and can be molded without crosslinking, and the molded product has rubber elasticity. As the monomer constituting the soft segment, vinylidene fluoride, tetrafluoroethylene, hexafluoropropene or the like is used, and for example, vinylidene fluoride-hexafluoropropene-tetrafluoroethylene terpolymer segment or the like is formed. . Further, examples of the monomer constituting the hard segment include vinylidene fluoride, ethylene, tetrafluoroethylene and the like. For example, polyvinylidene fluoride segment, tetrafluoroethylene-ethylene copolymer segment and the like are formed.

The epichlorohydrin type rubber is a ring-opening polymer of a cyclic ether mainly containing epichlorohydrin. As a monomer, usually epichlorohydrin (hereinafter,
ECH), ethylene oxide (hereinafter referred to as EO), and allyl glycidyl ether (hereinafter referred to as AGE) are used. From these monomers, ECH homopolymers such as polyepichlorohydrin (CO), ECH-EO
Epichlorohydrin-ethylene oxide copolymer (ECO) of copolymer, epichlorohydrin-allyl glycyl ether copolymer (GC of ECH-AGE copolymer
O), and also the ECH-EO-AGE terpolymer epichlorohydrin-ethylene oxide-allyl glycyl ether terpolymer (GECO).

(Polyparaxylylene) In the present invention, polyparaxylylene includes polyparaxylene and derivatives thereof, and the basic structure and manufacturing method thereof are described in US Pat. No. 3,379.
No. 803 and Japanese Patent Publication No. 52-37479. A specific example of the basic structure is represented by chemical formula (1)-
It shows in (6).

[0022]

[Chemical 1]

(Here, n is an integer of 5000 or more.) The polyparaxylene derivative is vapor-deposited on the surface of the rubber elastic body, and the film thickness is in the range of 0.1 to 100 μm, preferably 1 to 30 μm. Adjusted to. The film thickness is 0.
If it is less than 1 μm, the chemical resistance is lowered and pinholes are generated. On the other hand, when the coating thickness exceeds 100 μm, the ability of the coating to follow the rubber elastic body is poor, and whitening or cracking of the coating easily occurs due to bending or the like.

(Surface treatment of rubber elastic body) <Alkali detergent treatment> In the present invention, in order to form a film of the polyparaxylene derivative on the surface of the rubber elastic body, first the surface of the rubber elastic body is treated with an alkali detergent. To do. The alkaline detergent is an aqueous solution having a pH of 7 or more and 14 or less, and for example, an aqueous solution of an alkali metal salt such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, calcium hydroxide or calcium carbonate, or an alkaline earth metal salt can be used.
Further, an alkaline buffer solution may be used to stabilize the cleaning effect of the alkaline cleaner. Further, electrolytic reduced water obtained by electrolyzing an electrolytic aqueous solution of sodium chloride or sodium hydroxide can also be used.

As the alkaline cleaning agent, for example, "Eye Clean" commercially available from Inei Seieido Co., Ltd. as a cleaning agent for ultrasonic cleaners can be used. It contains nonionic surfactants, special builders, chelating agents and purified water as ingredients,
It has a specific gravity of 1.01 to 1.02 at pH 12.

In order to treat the surface of the rubber elastic body with the alkali cleaner, for example, the rubber elastic body is immersed in the alkali cleaner, and the temperature is in the range of room temperature to 60 ° C. and the cleaning is performed for about 5 to 30 minutes. In this case, ultrasonic waves may be used together.
It is also possible to wash only a part of the surface of the rubber elastic body with an alkaline detergent.

<Treatment with Silane Coupling Agent> The surface of the rubber elastic body treated with the alkali detergent is treated with the silane coupling agent. The silane coupling agent is soluble in an organic solvent such as alcohol, benzene or toluene.
Here, the solution concentration of the silane coupling agent is 5 to 30 wt.
It is preferably adjusted to the range of%. Then, the solvent is dried and removed, washed with purified water, and further dried. The method of treating these silane coupling agents is an example, and the present invention is not limited to this method.

As the silane coupling agent used in the present invention, a commonly used one can be used. Here, the silane coupling agent is represented by the following general formula (7).

[0029]

[Chemical 2]

(Here, OR is an alkoxy group, R'is an amino group, a mercapto group, a vinyl group, an epoxy group, etc.) As a specific silane coupling agent, bis (3-triethoxysilylpropyl) tetrasulfide is used. , Screw (2
-Triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane,
3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, 3
-Chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane and the like can be mentioned.

<Etching by Corona Discharge> Although not essential in the present invention, it is preferable to etch the surface of the rubber elastic body by corona discharge after the treatment with the alkali cleaner. Corona discharge can be applied as it is as a general-purpose technology, but for example, it has a structure with an insulator between the electrode and the counter electrode (earth), so that a high frequency high voltage and an air gap between the electrode and the work are generated. The characteristic corona treatment device manufactured by Tantech Co., Ltd. can be preferably used.

(Formation of Polyparaxylylene Film) To form a polyparaxylylene film on a rubber elastic body, a vapor deposition method is used. The vapor deposition method comprises the following three steps.
A method of vapor-depositing the polyparaxylylene of the formula (1) will be described below. In the first step, vaporization of diparaxylylene, which is a solid dimer as a raw material, occurs as shown in formula (8). In the second step, diradical paraxylylene is generated by thermal decomposition of the dimer as shown in formula (9). In the third step, the paraparaxylylene film of the formula (10) is formed on the surface of the rubber elastic body.

[0033]

[Chemical 3]

The temperature in the first step is 170 ° C. or lower,
The degree of vacuum is 135pa or less, the temperature in the second step is 680 ° C or less, the degree of vacuum is 70pa or less, the temperature in the third step is 35 ° C or less, and the degree of vacuum is 15p.
It is preferably a or less. In this series of steps, the diradical para-xylene, which is a thermal decomposition product of the dimer produced in the gas phase, has excellent penetrability into the details, so double bonds and radicals in the rubber molecular chain on the rubber elastic body surface It is presumed to polymerize to form a stable chemical bond.

An apparatus used in the vapor deposition method is shown in FIG. 1 for example. In FIG. 1, the vapor deposition apparatus comprises a vaporization chamber 1 for carrying out the first step, a thermal decomposition chamber 2 for carrying out the second step, a vapor deposition chamber 3 for carrying out the third step, and a deodorant / cooling tube 4 is additionally provided. ing.

The paraxylylene film formed on the surface of the rubber elastic body thus formed adheres to the surface and is firmly bound to the rubber molecules, and follows the extreme repeated deformation of the rubber elastic body, The film does not peel off.

(Rubber Elastic Body Compounding Agent) In the present invention, the rubber elastic body preferably contains carbon black as a filler. Various grades of carbon black are used, for example, SAF (N-110), I
SAF-LS (N-219), ISAF-HM (N-2
20), ISAF-LM (N-231), ISAF-H
S (N-242), CF (N-293), SCF (N-
294), EPC (S-300), MPC (S-30)
1), HAF-LS-SC (S-315), HAF-L
S (N-326), HAF (N-330), HAF-H
S (N-347), SPF (N-358), FF (N-
440), XCF (N-472), FEF-LS (N-
539), FEF (N-550), FEF-HS (N-
568), HMF (N-601), GPF (N-66).
0), APF (N-683), SRF-LM (N-76).
1) or SRF-HM (N-770) or the like can be used.

Among these carbon blacks, those having an average particle size of 100 μm or less, particularly 20 to 50 μm are preferably used. The blending amount of carbon black is 100 parts by mass or less, and more preferably 10 to 70 parts by mass with respect to 100 parts by mass of the rubber component.

The rubber elastic body may use silica as a reinforcing agent. As silica, either wet white carbon or dry white carbon can be used. For example, as the trade name of silica, curverex,
There are wet white carbons such as Nipseal, Tokuseal, Vitaseal and Himedil. Dry white carbon has Aerosil as its product name. Here, white carbon having an average particle size of 10 to 80 μm is preferably used, and the blending amount thereof is preferably less than 30 parts by mass with respect to 100 parts by mass. Further, a non-reinforcing filler together with the reinforcing filler, such as calcium silicate, diatomaceous earth, graphite, mica, calcium carbonate,
Zinc oxide or the like can be used, and these non-reinforcing fillers can be blended in less than 50 parts by mass with respect to 100 parts by mass of the rubber component.

A vulcanization accelerator is added to the rubber elastic body in an amount of 0.5 to 10 parts by mass, more preferably 2.0 to 7.0 parts by mass, based on 100 parts by mass of the rubber component. Here, as the vulcanization accelerator, aldehyde-ammonia-based vulcanization accelerators such as hexamethylenetetramine, guanidine-based vulcanization accelerators such as diphenyl and guanidine, and thiazole-based vulcanization agents such as 2-mercaptobenzothiazole and dibenzothiazyldisulfide. Sulfenamide-based vulcanization accelerators such as sulfur accelerator, cyclohexyl benzothiazyl sulfenamide, N-oxydiethylene benzothiazyl-2-sulfenamide, Nt-butyl-2-benzothiazole sulfenamide Tetramethylthiuram disulfide,
Thiuram vulcanization accelerators such as tetraethyl thiuram disulfide, tetramethyl thiuram monosulfide, etc., dithioate salts such as Zn-dimethyl dithiocarbamate, Zn-diethyl dithiocarbamate, Zn-di-n-butyl dithiocarbamate Vulcanization accelerators, thiourea-based vulcanization accelerators such as ethylene / thiourea and diethyl / thiourea are used, but the types thereof are not particularly limited.

A plasticizer may be added for the purpose of improving the fluidity, cold resistance and oil resistance of the rubber elastic body.
Here, as the plasticizer, DBP, DOP, DOA, TCP,
W320 or the like can be used. The plasticizer is blended in less than 30 parts by mass with respect to 100 parts by mass of the rubber component. Further, an antioxidant can be blended in order to improve the heat resistance and ozone resistance of the rubber elastic body. The antiaging agent is not particularly limited, but examples thereof include 2-mercaptobenzimidazole (MBI), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMDQ), nickel dibutyldithiocarbamate (NiDBC), and the like. Can be used. The anti-aging agent is usually used in the amount of 3.
It is blended in an amount of 0 part by mass or less.

As the kneading method of the rubber elastic body, a Banbury mixer, an intermix and a roll are used.
The kneading temperature in the roll is preferably 40 to 80 ° C. in consideration of tackiness. The extrusion die temperature is 80 to 1200 ° C, the calendar temperature during rolling is 40 to 80 ° C, and the vulcanization temperature is usually 120.
~ 180 ° C.

In order to adjust the rubber elastic body, for example, each compounding component except the crosslinking agent is kneaded with a kneader, and then the mixture is kneaded with a heating roll, and then the crosslinking agent is added, and a biaxial extruder is used. Method of adding compounding agent by a feeder and mixing from the middle, introducing each compounding component excluding the cross-linking agent from the twin-screw extruder to the single-screw extruder, then adding the cross-linking agent and processing it into a sheet with a T-die etc. The method of doing can be adopted.

(Use of Sealing Material) Since the sealing material of the present invention has excellent gas permeation resistance to carbon dioxide gas and excellent bending peeling resistance, a sealing material that comes into contact with carbon dioxide gas, such as an O-ring, a gasket or a packing. It can also be used for molding dies such as hoses or tubes and diaphragms. In addition, in the field of OA, electric and electronic equipment, it can be effectively used as a material for gas permeation resistance in the field of automobiles such as anode caps, various packings, and perkids.

[0045]

EXAMPLES (1) Rubber Elastic Body A rubber composition having the following composition was kneaded at 130 ° C. with a 10-inch open roll, and the kneaded product was press-vulcanized at 170 ° C. for 20 minutes. The test piece was prepared according to the Demachia flex crack test method for vulcanized rubber and thermoplastic rubber defined in JIS K6260. The test piece is 140 ~
The width was 155 mm, the width was 25 mm, and the thickness was 6.3 mm.
No groove is provided in the center of the test piece in the width direction.

(Rubber composition blend) Hydrogenated NBR (Note 1) 100 parts Carbon black (Note 2) 40 parts Zinc white 5 parts Stearic acid 2 parts Sulfur 0.5 parts Vulcanization accelerator ZTC (Note 3) 4 parts Vulcanization accelerator CZ (Note 4) 2 parts (Note 1) ZP0020 (hydrogenated acrylonitrile-budadiene rubber) manufactured by Zeon Corporation (Note 2) ISAF N220 (average particle diameter: 20 to 2)
5 μm) (Note 3) ZTC: Ouchi Shinko Chemical Co., Ltd. (zinc dibenzyldithiocarbamate) (Note 4) CZ: Ouchi Shinko Chemical Co., Ltd. (cyclohexyl
(Benzothiazylsulfenamide) (2) Treatment with Alkali Detergent The rubber elastic body was treated with an alkali detergent under the following conditions.

Alkaline cleaning agent (Note 1): Eyeclean A (Iuchi Seieidou Co., Ltd.) Cleaning agent concentration: 5% Cleaning temperature: 50 ° C. Cleaning time: 20 minutes (Note 1) Nonionic surfactant, special builder, chelate Contains agent and purified water, specific gravity 1.01 to 1.0 at pH 12
It is 2.

(3) Silane Coupling Agent Treatment Silane Coupling Agent: S310 Treatment Solution: 10% Toluene Solution Treatment Temperature: Room Temperature Treatment Time: 60 minutes The rubber elastic body is dipped in the above treatment solution, and 50 minutes at 50 ° C. It was dried, washed with water, and dried under reduced pressure for 30 minutes.

(4) Vapor phase vapor deposition Using the apparatus shown in FIG. 1, vapor phase vapor deposition was carried out on the surface of the rubber elastic body under the following conditions to form a vapor deposited thin film of 7 μm.

Raw material: Monochloroparaxylylene dimer Vaporization temperature / pressure: 150 ° C./100 pa Thermal decomposition temperature / pressure: 680 ° C./60 pa Deposition temperature / pressure: 30 ° C./10 pa (5) Corona discharge etching alkaline cleaner, rubber After treating the elastic body, corona discharge etching was performed under the following conditions.

Generator: HV2010 Transformer: HT10-28 (electrode is a quartz electrode having a width of 75 mm) Test conditions: Output 95 W, voltage 25 kv, processing speed 20 mm / sec For a sample obtained by subjecting the rubber elastic body to the above treatment, the following method is used. Then, the bending peeling test and the gas permeability were evaluated. Table 1 shows these examples and comparative examples.

<Peeling test> According to the de-matching bending crack test method defined in JISK6260, the test piece was bent 1000 times without forming a groove in the central width direction to peel the film on the surface of the rubber elastic body. The condition was evaluated according to the following criteria.

◯: All were not peeled off. Δ: Partially peeled.

X: All were peeled off. <Gas Permeability (Carbon Dioxide)> Rubber Cloth / Plastic Cloth Test Method-Part 10: Gas Permeability Measurement Method (K64
It was measured according to 04-10 (1999). The size of the test piece is 140 mm × 140 mm × 2 mm in a sheet form. The measurement principle is that a test piece is placed between two bahts of an airtight measurement cell and one surface of the test piece is exposed to carbon dioxide gas at a constant pressure, while carrier gas is introduced into the cell on the other surface. Flow at a constant speed to contact the test piece. The concentration of carbon dioxide gas in the carrier gas is measured by an analyzer provided at the outlet of the cell, and the transmittance of carbon dioxide gas in the test piece is measured from the result. The value without a coating is taken as 100 and shown as a relative value. The smaller the value, the better the carbon dioxide permeability. For those without numerical values, carbon dioxide gas leaked from the side surface of the test piece measurement cell, and measurement could not be performed.

[0055]

[Table 1]

<Evaluation Results> In Example 1, a polyparaxylylene film was formed after corona discharge etching, treatment with an alkaline cleaner and treatment with a silane coupling agent.
Flexibility and gas permeability are low. In Example 2, since the corona discharge etching was not performed, the bending releasability was slightly inferior.

In the comparative example, the polyparaxylylene film was formed after the treatment with either the alkaline detergent or the treatment with the silane coupling agent was omitted. Therefore, the flexural releasability and the gas permeability were poor. In particular, Comparative Examples 2, 3, 4, 5,
In No. 6, carbon dioxide gas leaked from the side surface of the measuring cell due to poor adhesion of the film.

[0058]

As described above, according to the present invention, a polyparaxylylene film is formed on the surface of a rubber elastic body after treatment with an alkaline detergent and a silane coupling agent. small. Furthermore, by performing corona discharge etching after the treatment with the alkaline cleaning agent, the bending releasability is improved and the gas permeability is reduced.

[Brief description of drawings]

FIG. 1 shows a schematic diagram of an apparatus for vapor deposition.

[Explanation of symbols]

1 vaporization chamber, 2 pyrolysis chamber, 3 vapor deposition chamber.

Claims (4)

[Claims] 1. A method for producing a sealing material having a polyparaxylylene film formed on the surface of a rubber elastic body, wherein the surface of the rubber elastic body is treated with an alkali cleaning agent and then treated with a silane coupling agent for adhesion. The method for producing a sealing material as described above, wherein the paraxylylene film is formed by a vapor deposition polymerization method. 2. The method for producing a sealing material according to claim 1, wherein the surface of the rubber elastic body is etched by corona discharge after the treatment with the alkaline detergent. 3. The method for producing a sealing material according to claim 1, wherein the polyparaxylylene is polyparaxylylene, polymonochloroparaxylylene or polydichloroparaxylylene. 4. The rubber elastic body is acrylonitrile-butadiene rubber (NBR) or hydrogenated acrylonitrile-butadiene rubber (hydrogenated NBR).
A method for producing the described sealing material.