JPH0734061A - Fluororubber-based sealing material and sealing method using the same - Google Patents

Abstract

(57) [Summary] [Structure] A fluororubber-based coating composed of fluororubber obtained by copolymerizing tetrafluoroethylene and propylene, a silane coupling agent containing an alkenyl group, a solvent, and an organic peroxide is cured. And a sealing method in which, when sealing a base material, the above-mentioned fluororubber-based coating material is applied to the sealing portion, the base materials are superposed, and the fluororubber-based coating material is cured by heating to adhere. . [Effect] It has a strong adhesive force and excellent characteristics of fluororubber composed of tetrafluoroethylene and propylene, and can seal various natural or synthetic resins, metals, ceramics, concrete and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluororubber sealant, and more particularly to a fluororubber sealant having good adhesion to metal or the like without using a primer or the like and a sealing method using the same.

[0002]

2. Description of the Related Art Fluororubber obtained by copolymerizing tetrafluoroethylene and propylene has oil resistance, heat resistance,
It is used in a wide range of fields because of its excellent weather resistance and electrical insulation, and it is often required to bond an inorganic material such as metal or glass or an organic material such as natural or synthetic resin as a sealing material.

[0003]

In this case, in order to use the above-mentioned coating material containing fluororubber as a main component as a sealing material, it is necessary to firmly bond it to an inorganic or organic material. It was necessary to apply a coating, or to perform surface treatment. Further, the sealing material is usually molded in advance by a mold or the like and then incorporated in the assembly stage, and it is desired to perform on-site molding because the process can be omitted.

[0004]

The present invention has been made to solve the above-mentioned problems, and it comprises (A) a fluororubber obtained by copolymerizing tetrafluoroethylene and propylene, and (B) an alkenyl group. A fluororubber-based sealant comprising (C) a solvent for dissolving or dispersing components (C), (A) and (B), and a fluororubber-based sealant, and a base material are sealed. On the occasion,
The present invention provides a sealing method in which the sealing material is applied to the sealing portion, the base materials are overlapped with each other, and the sealing material is cured by heating and adhered.

The fluororubber of the component (A) used in the present invention contains tetrafluoroethylene and propylene in an amount of 30.
/ 70 to 70/30 (molar ratio), preferably 40/60
The copolymer is copolymerized at a ratio of 60/40, and various conventionally known polymerization methods such as bulk polymerization, suspension polymerization, emulsion polymerization and solution polymerization can be adopted in the production of this fluororubber. The fluororubber used in the present invention can be used in any molecular weight range.

The alkenyl group-containing silane coupling agent as the component (B) used in the present invention is a component for enhancing the adhesiveness between the fluororubber sealant and various substrates, and is represented by Chemical Formula 1. . This is because the component (B) adheres to the substrate due to hydrolysis of the alkoxy group, and one alkenyl group reacts with the fluororubber polymer during vulcanization to adhere the sealant to the substrate. It is considered to be a thing. As a result, a large adhesive force can be obtained even for those which cannot be adhered sufficiently or which cannot be adhered without using a conventional primer or the like.

[0007]

[Chemical 1]

Specific examples of the component (B) include vinyltrimethoxysilane and vinyltris (2-methoxyethoxy).
Examples thereof include silane, vinyltriethoxysilane, methylvinyldiethoxysilane, allyltrimethoxysilane, vinyltris (t-butylperoxy) silane, partial hydrolysates and partial cohydrolysates thereof, and these compounds are used alone. Or as a mixture of two or more kinds.

The amount of the component (B) used is 0.1 to 20 parts by weight, preferably 0.3 to 100 parts by weight, based on 100 parts by weight of the component (A).
It is in the range of 10 parts by weight. The solvent of the component (C) used in the present invention is for making a fluororubber into a coating material, and its kind and amount used are not particularly limited.
It is appropriately selected according to the purpose and usage. For example, at least one selected from aromatic and aliphatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, esters, ethers and the like can be used.

When the fluororubber sealing material of the present invention is applied to a base material and then heated and vulcanized, the organic peroxide of the component (D) is used as a vulcanizing agent. Organic peroxides include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, and 2,5-dimethyl-
2,5-di (peroxybenzoate) hexyne-3,
1,4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-
Butyl peracetate, 2,5-dimethyl-2,5-di (tert-butyl peroxy) hexyne-3,2,5
-Dimethyl-2,5-di (tert-butylperoxy) hexane, tert-butylperbenzoate, t
ert-butyl perphenylacetate or the like is used. The type and amount of the organic peroxide used are appropriately selected according to the application and method of use.

The organic titanate ester of component (E), organic tin ester of carboxylic acid, or aluminum alkoxide used in the present invention is a silane coupling containing an alkenyl group of component (B) when a sealing material is applied. It is a component for promoting the hydrolysis of the agent and increasing the adhesive force, and specific examples thereof include tetrabutyl titanate, tetrapropyl titanate, diisopropyl titanium acetylacetonate, dibutyltin diacetate, dibutyltin dilaurate, aluminum acetylacetonate. , Aluminum tributoxide, and the like. These may be used alone or as a mixture of two or more. (E)
The amount of the component used is in the range of 0.1 to 100 parts by weight based on 100 parts by weight of the total of the amounts of the component (B) and the component (F) described later, and is appropriately determined depending on the use conditions of the coating material.

The organic silicic acid ester of the component (F) used in the present invention has the effect of further increasing the adhesiveness of the coating material when used together with the component (B). Specific examples include tetramethyl orthosilicate and tetraethyl orthosilicate. Silicate, tetraisopropyl orthosilicate,
Examples thereof include tetrakis (2-methoxyethyl) orthosilicate and the like, or partial hydrolysates and partial cohydrolysates thereof. These may be used alone or as a mixture of two or more. The amount of the component (F) used is 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight, based on 100 parts by weight of the component (A).

The unsaturated polyfunctional compound as the component (G) used in the present invention acts as a vulcanization aid when vulcanizing the fluororubber sealant, and specific examples include triallyl isocyanurate and triary. Lucyanurate, trimethylolpropane trimethacrylate, polybutadiene and the like are used. The amount of component (G) used is 0.1 to 20 parts by weight, preferably 0.3 to 100 parts by weight, of component (A).
It is in the range of 10 parts by weight.

In the present invention, the fluororubber-based sealing material is an optional component such as silica, carbon, a filler such as glass fiber or carbon fiber, a pigment, a plasticizer and the like, if necessary, within a range not impairing the performance of the sealing material. Can be mixed. Moreover, it is also possible to use it by mixing with other sealing materials.

In the present invention, the fluororubber type sealing material can be easily manufactured by uniformly mixing the above-mentioned respective components. The fluororubber sealant thus obtained can be applied to other polymers or organic materials such as wood or metals, inorganic materials such as glass and ceramics by any method such as dipping, spraying, brush coating, etc. is there.

The coated sealing material can be vulcanized by heating and adhered to a base material to form a sealing material. As a result, it becomes possible to omit the step of molding the sealing material in advance by using a mold or the like, and it becomes possible to perform on-site molding work. The vulcanization conditions are determined depending on the working conditions and the like, but for example, at 100 ° C to 400 ° C for several seconds to
About 24 hours is common.

[0017]

In the present invention, the fluororubber sealant is such that the silane coupling agent having an alkenyl group reacts with the base material and the fluororubber to chemically bond the fluororubber to another inorganic or organic material, It is considered that it can be used as a sealing material without using a primer.

[0018]

EXAMPLES The present invention will be specifically described with reference to examples. In the examples, “part” means “part by weight”.

Example 1 100 parts of fluororubber of tetrafluoroethylene / propylene = 55/45 (molar ratio) and 30 parts by weight of MT carbon were uniformly mixed in two rolls. This and 3 parts of vinyltrimethoxysilane and 1 part of 1,4-bis (tert-butylperoxyisopropyl) benzene were mixed with 400 parts of butyl acetate.
To obtain a fluororubber-based sealing material.

The fluororubber sealing material thus obtained was applied to a stainless steel plate in a thickness of 0.5 mm, a stainless steel plate was further stacked thereon, dried at room temperature for 1 hour, and then heated at 170 ° C. for 10 minutes. . After cooling to room temperature, the adhesion was examined, and the rubber layer was cohesively broken.

Example 2 In Example 1, further 3 parts of tetraethyl orthosilicate,
A sealing material containing 3 parts of tetrabutyl titanate and 3 parts of triallyl isocyanurate was produced. When the adhesion to the stainless steel plate was examined in the same manner as in Example 1,
The rubber layer was cohesively broken.

Example 3 When the adhesion was examined in the same manner as in Example 2 except that the glass plate was used instead of the stainless steel plate, the rubber layer was cohesively broken.

Comparative Example 1 When a similar test was carried out in Example 1 without using vinyltrimethoxysilane, the sealing material was not adhered at all.

Comparative Example 2 A similar test was carried out in Example 3, except that vinyltriethoxysilane and 1,4-bis (tert-butylperoxyisopropyl) benzene were not used, but the sealing material was not adhered at all. .

[0025]

The sealing material of the present invention has a strong adhesive force and excellent characteristics of fluororubber composed of tetrafluoroethylene and propylene, and various natural or synthetic resins,
By applying it to metal, ceramics, concrete, wood, etc., it becomes possible to easily form a sealing material and it can be used in various industrial fields.

Claims (5)

[Claims] 1. A fluororubber obtained by copolymerizing (A) tetrafluoroethylene and propylene, (B) a silane coupling agent containing an alkenyl group, and (C) components (A) and (B) dissolved or A fluororubber-based sealing material comprising a solvent to be dispersed and (D) an organic peroxide. 2. The fluororubber sealant according to claim 1, which contains (E) an organic titanate ester, an organic tin ester of a carboxylic acid, and at least one compound selected from aluminum alkoxides. 3. The fluororubber sealant according to claim 1, which contains (F) an organic silicate ester. 4. The fluororubber sealant according to claim 1, which contains (G) an unsaturated polyfunctional compound. 5. A sealing method in which, when sealing a base material, the fluororubber sealing material according to claim 1 is applied to the sealing portion, the base materials are superposed, and then the sealing material is cured by heating to adhere. .