JPH0679828A - Rubber laminated body - Google Patents

Abstract

PURPOSE:To obtain a rubber laminated body holding excellent adhesive force after thermal deterioration by bonding strongly a fluororubber and an acryllc rubber with crosslinking. CONSTITUTION:A crosslinked rubber laminated body is obtd. by laminating an uncrosslinked rubber layer wherein a fluororubber is a main ingredient and an uncrosslinked rubber layer wherein an acrylic rubber is a main ingredient. In addition, in at least one of the fluororubber layer and the acrylic rubber layer, a liq. diene rubber with a functional group and a compd. contg. an element of the second group in the periodic table is compounded. It is possible thereby to obtain a laminated body with the acrylic rubber while heat resistance, oil resistance, chemical resistance and weatherability which are features of the fluororubber are kept.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate of fluororubber and acrylic rubber, and in the adhesion of fluororubber and acrylic rubber, they are firmly bonded by cross-linking without using an intermediate or an adhesive, and further heat aged. The present invention also relates to a laminate of a fluororubber and an acrylic rubber which has excellent adhesive strength afterwards.

[0002]

2. Description of the Related Art In recent years, the demands on the performance of rubber materials have become stricter year by year, and the types of rubber materials used have changed. Among the rubbers, fluororubber has outstanding performance in solvent resistance, heat resistance, chemical resistance, and weather resistance compared to other special rubbers, and its demand is increasing year by year in the field of industrial goods, automobiles and aircraft. It has increased. However, its price is extremely high compared to elastomers other than fluororubber, and its high specific gravity causes a marked increase in product price, so that the fields of use have been limited. In this way, it can be said that it has become difficult to deal with one kind of rubber material in order to simultaneously satisfy the contradictory requirements of high performance and low price. To meet such demands, a method of mixing or laminating an elastomer other than fluororubber with fluororubber has been proposed. However, in the former case, it is difficult to obtain a uniform mixed state, and sufficient performance has not yet been achieved. Further, in the case of lamination, strong adhesion to an elastomer other than fluororubber is difficult due to the low surface energy and low reactivity that are characteristics of fluororubber, and as a laminated structure with an elastomer other than fluororubber, The use was limited. Therefore, various studies have been made in the past to obtain a rubber laminate having a structure in which a fluororubber layer and an acrylic rubber layer having a good balance between heat resistance and oil resistance are vulcanized and bonded. For example, those which are cross-linked by addition of a triazine compound (Japanese Patent Laid-Open Nos. 55-159975 and 58-2207).
No. 32 publication), a fluororubber compound layer is cross-linked with polyol /
Acrylic rubber compound layer cross-linked with a guanidine compound (JP-A-61-169243), fluororubber compound layer polyol cross-linking / acrylic elastomer with peroxide, quaternary ammonium bromide, and epoxidation A composition comprising a compound layer containing a fatty acid ester (Japanese Patent Laid-Open No. 61-189934) has been proposed. These have obtained relatively good adhesive strength by vulcanization adhesion, but when practicability was taken into consideration and a heat aging test was performed, the performance deteriorated and the requirements could not be sufficiently satisfied. .

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to obtain a rubber laminate in which fluororubber and acrylic rubber are firmly adhered to each other, and even after heat aging, excellent adhesive strength is maintained.

[0004]

DISCLOSURE OF THE INVENTION According to the present invention, a rubber obtained by superposing and cross-linking an uncrosslinked rubber layer (A) containing a fluororubber as a main component and an uncrosslinked rubber layer (B) containing an acrylic rubber as a main component. A laminated body, in which at least one of (A) layer and (B) layer is blended with a liquid diene rubber having a functional group and a compound containing a Group II element of the periodic table. Laminate.

The present invention will be described in more detail below. The fluororubber in the present invention includes the following.
As the fluorine-containing monomer, vinylidene fluoride,
Hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro (methyl vinyl ether), perfluoro (propyl vinylidene), etc. can be used and further copolymerized with them. As a monomer, a rubber obtained by copolymerizing a vinyl compound such as an acrylate ester, an olefin compound such as propylene or a diene compound, a halogen-containing vinyl compound containing chlorine, bromine, or iodine can be given. Specifically, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-propylene copolymer, tetrafluoride Ethylene-vinylidene fluoride-propylene terpolymer and the like,
Of these, the tetrafluoroethylene-propylene binary copolymer and the tetrafluoroethylene-vinylidene fluorolide-propylene terpolymer are preferable.

Next, the acrylic rubber of the present invention is (meth)
Examples thereof include a polymer of an acrylic acid alkyl ester or a copolymer containing the alkyl ester as a main component and a second component having an active group. Among these, as the alkyl ester of (meth) acrylic acid,
One or more of ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and the like can be mentioned. Examples of the second component having an active group include dicyclopentadiene, ethylidene norbornene, vinyl chloroacetate, allyl chloroacetate, 2-chloroethyl vinyl ether, vinyl acrylate, allyl methacrylate, glycidyl methacrylate, dimethylstyryl vinyl silane, dicyclopentenyl. One or more of acrylate, dicyclopentenyloxyethyl acrylate, alkyl glycidyl ether, vinyl glycidyl ether, 2-chloroethyl acrylate, vinyl monochloroacetate, vinyl norbornene, acrylic acid, methacrylic acid, itaconic acid, etc. may be mentioned. it can. The second component having these active groups is 15% by weight or less, preferably 10% by weight of (meth) acrylic acid alkyl ester.
It is used in the following range. Furthermore, in the acrylic rubber, as the third component, acrylonitrile, styrene,
One or two or more kinds of monomers such as 1,3-butadiene, isoprene, chloroprene, ethylene, propylene and vinyl acetate can be used together in an amount of about 40% by weight or less.

In the present invention, a liquid diene rubber having a functional group is compounded in at least one of the rubber layer (A) and the rubber layer (B) and a compound containing a periodic group II element.

Examples of the functional group include a hydroxyl group, an isocyanate group, a carboxy group, an epoxy group, an acryloyl group, an amino group and a mercapto group, and among them, the hydroxyl group is preferable. Examples of the liquid diene rubber include liquid polybutadiene, liquid polyisoprene, liquid styrene-butadiene copolymer, liquid acrylonitrile-butadiene copolymer, and liquid polychloroprene, among which liquid polybutadiene is preferable.

The functional group content of the liquid diene rubber is
Preferably 0.01 to 30 per 1 g of liquid diene rubber
It is milliequivalent, more preferably 0.1 to 5 meq, and the bonding position of the functional group is preferably at the molecular end. The number average molecular weight of the liquid diene rubber is preferably 500 to 50,
000, and more preferably 800 to 10,000. The amount of the liquid diene rubber used is 0.1 to 30 parts by weight, preferably 0.5 to 15 parts by weight, per 100 parts by weight of the fluororubber or acrylic rubber of at least one layer. If the amount of the liquid diene rubber added is less than 0.1 part by weight, sufficient adhesive force cannot be obtained, and if it exceeds 30 parts by weight, the physical properties of the compound are impaired.

The elements of Group II of the periodic table include beryllium, magnesium, calcium, zinc, strontium, cadmium, barium, mercury and radium, of which magnesium is preferred. Examples of the compound include oxides, hydroxides, carbonates and metallic soaps,
Of these, oxides are preferred. You may use 2 or more types of compounds containing the said group II element.

The compounding amount of the compound containing the Group II element is 0.1 to 30 parts by weight, preferably 0.5 to 15 parts by weight, per 100 parts by weight of the fluororubber or acrylic rubber of at least one layer. . If the compounding amount of the compound containing the Group II element is less than 0.1 parts by weight, sufficient adhesive force cannot be obtained, and if it exceeds 30 parts by weight, the physical properties of the compounding,
The workability is impaired.

In the present invention, an organic peroxide is mixed with fluororubber as a crosslinking agent. Examples of the organic peroxide to be mixed include diacyl peroxide such as dibenzoyl peroxide, dicumyl peroxide, di-t-
Monoperoxy compounds such as peroxyesters such as butyl peroxide, t-butyl peroxide acetate, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, and 2,
5-dimethyl-2,5-di- (t-butylperoxy)
-Hexyne-3,2,5-dimethyl-2,5-di- (t
-Butylperoxy) -hexane, α, α'-bis (t
-Butylperoxy) -p-diisopropylbenzene,
Examples include diperoxy compounds such as 2,5-dimethyl-2,5-di- (benzoylperoxy) -hexane. These may be used alone or in combination of two or more. The blending amount of the organic peroxide is preferably 0.01 to 10 with respect to 100 parts by weight of the fluororubber.
Parts by weight, more preferably 0.05 to 5 parts by weight.
If the amount is less than 0.01 parts by weight, the strength of the material is remarkably poor,
If it exceeds the weight part, the adhesive strength will decrease.

Upon crosslinking the organic peroxide, a bifunctional vinyl monomer or the like can be used as a crosslinking aid. Examples of the crosslinking aid that can be used include ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol-dimethacrylate, and polyethylene glycol dimethacrylate. Acrylate, 1,4-butanediol diacrylate, 1,6-
Hexanediol acrylate, 2,2'-bis (4-
Methacryloyldiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate, divinylbenzene, N, N'-methylenebisacrylamide, p-quinonedioxime, p, p'-
Examples thereof include dibenzoylquinone dioxime, triazine dithiol, triallyl cyanurate, triallyl isocyanurate, N, N'-phenylene bismaleimide and the like. The amount of the crosslinking aid added is usually 0.1 to 20 parts by weight, and preferably 0.5 to 100 parts by weight of the fluororubber.
~ 7 parts by weight.

The cross-linking agent for the acrylic rubber in the present invention may be any of sulfur or its derivatives or organic peroxides, which are generally used as a cross-linking agent for rubber, or an alkylphenol resin, which is further contained in the acrylic rubber. A polyfunctional crosslinking agent having two or more functional groups having reactivity with the crosslinking group can be mentioned. Examples of the organic peroxide used as the crosslinking agent include 2,5
-Dimethyl-2,5-di (t-butylperoxy) hexene-3,2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,2'-bis (t-butylperoxy) (Oxy) -p-diisopropylbenzene, dicumyl peroxide, di-t-butylperoxide, t-butylperbenzoate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane,
2,4-dichlorobenzoyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, azobisisobutyronitrile and the like, preferably 2,5-dimethyl-2,5-di (t-butylperoxy) ) Hexene-3,2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane, 2,2'-bis (t-
Butylperoxy) -p-diisopropylbenzene.

Upon crosslinking the acrylic rubber with an organic peroxide, a bifunctional vinyl monomer or the like can be used as a crosslinking aid. Examples of the crosslinking aid include the following compounds. That is, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol-dimethacrylate,
Polyethylene glycol dimethacrylate, 1,4-
Butanediol diacrylate, 1,6-hexanediol diacrylate, 2,2'-bis (4-methacryloyldiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, divinylbenzene. , N, N′-methylenebisacrylamide, p-quinonedioxime, p, p′-dibenzoylquinonedioxime, triazinedithiol, triallyl cyanurate, triallyl isocyanurate, bismaleimide and the like. The amount of the crosslinking aid added is 0.1 to 10 parts by weight, preferably 0.5 to 7 parts by weight, based on 100 parts by weight of the rubber component.

The polyfunctional crosslinking agent having two or more functional groups having reactivity with the crosslinking group present in the acrylic rubber is preferably an amino group, an isocyanate group, a maleimide group, an epoxy group, a hydroxyl group and It is a polyfunctional crosslinking agent having two or more functional groups of at least one selected from the group consisting of carboxyl groups, and is diamines, polyamines, diisocyanates, polyisocyanates, maleimides, diepoxides, diols, polyols. And compounds such as dicarboxylic acids. Specific examples of these compounds include hexamethylenediamine and ammonium benzoate.

Further, when an epoxy group-introduced elastomer is used as the acrylic rubber, polyamine carbamates, organic carboxylic acid ammonium salts, dithiocarbamate salts or organic carboxylic acid alkali metal salts are combined with a sulfur compound for crosslinking. Agents can also be used. Furthermore, when an elastomer having a halogen group introduced into acrylic rubber is used, a cross-linking agent in which a polyamine carbamate, an organic carboxylic acid ammonium salt or an organic carboxylic acid alcal metal salt, and a sulfur compound are combined may also be used. it can.

The amount of the crosslinking agent added is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the acrylic rubber. If the amount of the crosslinking agent used is too small, the mechanical strength and oil resistance will be insufficient, and if it is too large, the adhesive strength will decrease.

In the present invention, various commonly used compounding agents may be added to the fluororubber and acrylic rubber. Examples thereof include carbon black, fumed silica, wet silica, fine quartz powder, diatomaceous earth, zinc white, basic magnesium carbonate, activated calcium carbonate, magnesium silicate, aluminum silicate,
Titanium dioxide, talc, mica powder, aluminum sulfate,
Calcium sulfate, barium sulfate, asbestos, graphite, wollastonite, molybdenum disulfide, carbon fiber,
Examples include aramid fiber, various whiskers, glass fiber, organic reinforcing agent, and organic filler.

Further, as the dispersion aid, higher fatty acid and its metal amine salt; as the plasticizer, for example, phthalic acid derivative, adipic acid derivative, sebacic acid derivative; as the softening agent, for example, lubricating oil, process oil, coal Tar, castor oil, calcium stearate; Antiaging agents such as phenylenediamines, hindered amines, phosphates, quinolines, cresols, phenols, dithiocarbamate metal salts; other colorants, UV absorbers, flame retardants , An oil resistance improver, a foaming agent, an anti-scorch agent, a tackifier, a lubricant and the like can be optionally mixed. These blends can be kneaded by a usual kneading machine such as a roll or a Banbury mixer, and then molded and crosslinked under the usual production conditions of a crosslinked rubber. The crosslinking temperature, crosslinking time, and pressure are not particularly limited, but an uncrosslinked rubber layer containing a fluororubber as a main component and an uncrosslinked rubber layer containing an acrylic rubber as a main component are contacted in an uncrosslinked state, and usually 2 to 100 to ²⁰ under the pressure of 100 kg / cm ² G
A crosslinked laminate is obtained by heating to 0 ° C.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Examples 1 to 11 and Comparative Examples 1 to 6 Fluorine rubber and acrylic rubber were compounded according to Tables 1 and 2,
The mixture was kneaded on a 40 ° C. roll. The kneaded and non-crosslinked 2 mm thick sheets were brought into contact with each other, press-crosslinked for 40 minutes at 160 ° C., punched out to a width of 1 cm, and JIS K6854 was used.
A T-peel test was performed according to -1973. The results are shown in Table 3. Aging test is air heating aging 150 ℃ × 2
It was carried out for 4 hours.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

As shown in the table, it can be seen that the laminate obtained by mixing liquid polybutadiene rubber having a hydroxyl group on at least one of the sheets and magnesium oxide has a significantly improved adhesive strength not only in the original but also after heat aging. .

[0026]

According to the present invention, a rubber laminate in which fluororubber and acrylic rubber are strongly crosslinked and bonded can be obtained. Further, the present invention is heat resistance, oil resistance, which is a feature of fluororubber,
It is possible to obtain a laminate with acrylic rubber while maintaining chemical resistance and weather resistance. The laminate of the present invention is used as a chemical plant, food plant equipment and food equipment, nuclear power plant equipment, general industrial parts, and various hoses in vehicles such as automobiles, ships and aircraft, for example, steam resistant hoses, oil hoses, Gas hoses, brake oil hoses, chemical resistant hoses, freon hoses, and the like. Examples of industrial parts include packing, diaphragms, linings, rolls, blankets, pads, and
It can be used for rubber parts such as belts, mandrels, flexible joints, rubber plates, and weather strips where fluororubber and acrylic rubber are used.

Claims (1)

[Claims] 1. A rubber laminate in which an uncrosslinked rubber layer (A) containing a fluororubber as a main component and an uncrosslinked rubber layer (B) containing an acrylic rubber as a main component are superposed and crosslinked,
A rubber laminate comprising a liquid diene rubber having a functional group and a compound containing a Group II element of the periodic table in at least one of the layers (A) and (B).