JP2020049691A - Rubber laminate and hose - Google Patents

Abstract

To provide a rubber laminate comprising an epihalohydrin-based rubber layer and a fluororubber layer which is excellent in balance between permanent compression set resistance and elongation at break, has excellent heat resistance and is excellent in adhesiveness between an epihalohydrin-based rubber layer and a fluororubber layer.SOLUTION: There is provided a rubber laminate which comprises: an epihalohydrin-based rubber layer (A) composed of an epihalohydrin-based rubber composition comprising an epihalohydrin-based rubber containing 55 to 90 mol% of an epihalohydrin monomer unit and 10 to 45 mol% of an alkylene oxide monomer unit, silica, a quinoxaline-based crosslinking agent, an acid acceptor and a sulfur atom-containing silane coupling agent; and a fluororubber layer (B) composed of a fluororubber composition comprising a fluororubber and a polyol-based crosslinking agent.SELECTED DRAWING: None

Description

  The present invention relates to a rubber laminate comprising an epihalohydrin-based rubber layer composed of an epihalohydrin-based rubber composition and a fluororubber layer composed of a fluororubber composition, and more particularly, to a balance between compression set resistance and elongation at break. The present invention relates to a rubber laminate having excellent, excellent heat resistance, and excellent adhesion between an epihalohydrin-based rubber layer and a fluororubber layer.

  Fluororubber has excellent heat resistance, oil resistance, solvent resistance, chemical resistance, and the like, and is therefore widely used in various fields such as the automobile industry, the semiconductor industry, and the chemical industry. For example, for automotive applications, they are used as hoses and sealing materials for engines and peripheral devices, AT devices, fuel systems, and peripheral devices.

  However, since fluororubber is expensive, hoses and sealing materials are not usually made of fluororubber alone.For example, when manufacturing a fuel hose or air hose, fluororubber is used as an inner thin layer. For the outside, a laminated structure using a rubber other than fluororubber is employed.

  For example, Patent Document 1 discloses that 0.1 to 10 parts by weight of a 2,3-dimercaptoquinoxaline derivative and 1 to 20 parts by weight of hydrotalcite, based on 100 parts by weight of an unvulcanized fluororubber composition and epichlorohydrin rubber. A vulcanized rubber laminate is disclosed in which an unvulcanized epichlorohydrin-based rubber composition containing a compounding agent consisting of parts is bonded by heating and vulcanizing. However, the rubber laminate disclosed in Patent Literature 1 has a problem that compression set is high, and adhesion between the fluororubber layer and the epichlorohydrin-based rubber layer is insufficient.

JP-A-9-85898

  The present invention has been made in view of such circumstances, has an excellent balance between compression set resistance and elongation at break, has excellent heat resistance, and an epihalohydrin-based rubber layer and a fluorine rubber layer. An object of the present invention is to provide a rubber laminate having excellent adhesiveness.

  The present inventors have conducted intensive studies to achieve the above object, and as a result, a fluororubber and a fluororubber layer composed of a fluororubber composition containing a polyol-based crosslinking agent, an epihalohydrin-based rubber having a specific composition, According to the rubber laminate obtained by laminating an epihalohydrin-based rubber layer composed of an epihalohydrin-based rubber composition containing silica, a quinoxaline-based crosslinking agent, an acid acceptor, and a sulfur atom-containing silane coupling agent, The inventors have found that the problem can be solved, and have completed the present invention.

That is, according to the present invention, an epihalohydrin-based rubber containing 55 to 90 mol% of an epihalohydrin monomer unit and 10 to 45 mol% of an alkylene oxide monomer unit, silica, a quinoxaline-based crosslinking agent, An epihalohydrin-based rubber layer (A) comprising an epihalohydrin-based rubber composition containing an agent and a sulfur atom-containing silane coupling agent;
A rubber laminate including a fluororubber layer (B) made of a fluororubber composition containing a fluororubber and a polyol-based crosslinking agent is provided.

  In the rubber laminate of the present invention, the sulfur atom-containing silane coupling agent is preferably a mercapto group-containing silane coupling agent.

  Further, according to the present invention, there is provided a hose using the above-described rubber laminate.

  According to the present invention, there is provided a rubber laminate having an excellent balance between compression set resistance and elongation at break, excellent heat resistance, and excellent adhesion between an epihalohydrin-based rubber layer and a fluororubber layer. can do.

The rubber laminate of the present invention comprises an epihalohydrin-based rubber containing 55 to 90 mol% of an epihalohydrin monomer unit and 10 to 45 mol% of an alkylene oxide monomer unit, silica, a quinoxaline-based crosslinking agent, and an acid acceptor. An epihalohydrin-based rubber layer (A) comprising an epihalohydrin-based rubber composition containing an agent and a sulfur atom-containing silane coupling agent;
A fluororubber layer (B) comprising a fluororubber composition containing a fluororubber and a polyol-based crosslinking agent is provided.

<Epihalohydrin rubber composition>
The epihalohydrin-based rubber composition constituting the epihalohydrin-based rubber layer (A) of the rubber laminate of the present invention comprises an epihalohydrin-based rubber, silica, a quinoxaline-based crosslinking agent, an acid acceptor, and a sulfur atom-containing silane coupling agent. And

<Epihalohydrin rubber>
The epihalohydrin rubber used in the present invention is a rubber polymer containing an epihalohydrin monomer unit as an essential constituent monomer unit, and contains 55 to 90 mol% of an epihalohydrin monomer unit and 10 to 10 mol% of an alkylene oxide monomer unit. Contains 45 mol%.

  The epihalohydrin rubber used in the present invention may be any as long as the epihalohydrin monomer unit and the alkylene oxide monomer unit are in the above ranges. One type may be used alone, or two or more copolymers of epihalohydrin monomers and alkylene oxide monomers having different monomer compositions may be used in combination. Furthermore, a homopolymer of an epihalohydrin monomer or a copolymer of two or more epihalohydrin monomers and a copolymer of one or more epihalohydrin monomers and an alkylene oxide monomer May be used in combination. When two or more polymers having different monomer compositions are used in combination, the amounts of the epihalohydrin monomer unit and the alkylene oxide monomer unit in the entire polymer having the different monomer composition are set in the above ranges. And it is sufficient.

  Examples of the epihalohydrin monomer forming the epihalohydrin monomer unit include, for example, epichlorohydrin, epibromohydrin, epiiodohydrin, 2-methylepichlorohydrin, 2-methylepibromohydrin, Ethyl epichlorohydrin and the like. These may be used alone or in combination of two or more. Among these, epichlorohydrin is preferred from the viewpoint that the obtained rubber laminate can have excellent compression set resistance and elongation at break.

  The content ratio of the epihalohydrin monomer unit in the epihalohydrin rubber is 55 to 90 mol%, preferably 67 to 90 mol%, more preferably 67 to 90 mol%, based on all the monomer units constituting the epihalohydrin rubber. 70-85 mol%. When an unsaturated epoxide monomer unit described later is contained in the epihalohydrin rubber, the content ratio of the epihalohydrin monomer unit is 55% with respect to all monomer units constituting the epihalohydrin rubber. It is preferably at most 70 mol%, more preferably at most 55 to 65 mol%. If the content of the epihalohydrin monomer unit is too small, the resulting rubber laminate will have reduced compression set and heat resistance. On the other hand, if the amount is too large, the adhesive strength between the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) in the obtained rubber laminate decreases, and problems such as peeling tend to occur. When two or more polymers having different monomer compositions are used in combination, the amount of epihalohydrin monomer units in the entire polymer having different monomer compositions may be within the above range.

  Examples of the alkylene oxide monomer forming the alkylene oxide monomer unit include ethylene oxide, propylene oxide, 1,2-epoxybutane, 1,2-epoxy-4-chloropentane, 1,2-epoxyhexane, Or branched chains such as 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxyoctadecane, 1,2-epoxyeicosane, 1,2-epoxyisobutane, and 2,3-epoxyisobutane Alkylene oxide; cyclic alkylene oxide such as 1,2-epoxychloropentane, 1,2-epoxycyclohexane, 1,2-epoxycyclododecane; butyl glycidyl ether, 2-ethylhexyl glycidyl ether, 2-methyloctyl glycidyl ether, neopentyl Glycol glycol Glycidyl ethers having an alkyl long chain or a branched chain such as jyl ether, decyl glycidyl ether and stearyl glycidyl ether; glycidyl ethers having an oxyethylene side chain such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether; And these may have a substituent such as a halogen atom. One of these alkylene oxide monomers may be used alone, or two or more thereof may be used in combination. Among these, linear alkylene oxides are preferred, and ethylene oxide and propylene oxide are more preferred from the viewpoint that the resulting rubber laminate can have better compression set resistance and elongation at break, Ethylene oxide is particularly preferred.

  The content ratio of the alkylene oxide monomer unit is 10 to 45 mol%, preferably 10 to 33 mol%, more preferably 15 to 30 mol%, based on all the monomer units constituting the epihalohydrin rubber. . In the case where an unsaturated epoxide monomer unit described below is contained in the epihalohydrin rubber, the content ratio of the alkylene oxide monomer unit is based on all monomer units constituting the epihalohydrin rubber. The content is preferably from 22 to 44.9 mol%, more preferably from 29 to 44.5 mol%. If the content ratio of the alkylene oxide monomer unit is too small, the adhesive strength between the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) in the obtained rubber laminate is reduced, and defects such as peeling are caused. It is easy to occur. On the other hand, if it is too large, the resulting rubber laminate will have reduced compression set resistance and heat resistance. When two or more polymers having different monomer compositions are used in combination, the amount of the alkylene oxide monomer unit in the entire polymer having a different monomer composition may be within the above range.

  The epihalohydrin rubber used in the present invention may further contain an unsaturated epoxide monomer unit as a unit of a copolymerizable monomer.

  Examples of the unsaturated epoxide monomer forming the unsaturated epoxide monomer unit include unsaturated glycidyl ethers such as vinyl glycidyl ether, allyl glycidyl ether and o-allylphenyl glycidyl ether; butadiene epoxide, chloroprene epoxide, 4, Diene monoepoxides such as 5-epoxy-2-pentene, epoxy-1-vinylcyclohexene, 1,2-epoxy-5,9-cyclododecadiene; glycidyl acrylate, glycidyl methacrylate, glycidyl crotonate, glycidyl-4-heptenate; Glycidyl sorbate, glycidyl linoleate, glycidyl 3-cyclohexenecarboxylate, glycidyl 4-methyl-3-cyclohexenecarboxylate, glycidyl-4-methyl-3-pe Glycidyl esters of ethylenically unsaturated carboxylic acids such as Teneto; and the like, they may have a substituent such as a halogen atom. One of these unsaturated epoxide monomers may be used alone, or two or more thereof may be used in combination. Among these, unsaturated glycidyl ether is preferred, and allyl glycidyl ether is more preferred.

  When the unsaturated epoxide monomer unit is contained in the epihalohydrin rubber, the content ratio of the unsaturated epoxide monomer unit is preferably 0.1% with respect to all the monomer units constituting the epihalohydrin rubber. To 8 mol%, more preferably 0.5 to 6 mol%, still more preferably 1 to 4 mol%. When two or more polymers having different monomer compositions are used in combination, it is preferable that the amount of unsaturated epoxide monomer units in the entire polymer having different monomer compositions be within the above range. .

  The weight average molecular weight of the epihalohydrin rubber used in the present invention is preferably from 200,000 to 2,000,000, and more preferably from 400,000 to 1,500,000. When the weight average molecular weight is in the above range, the mechanical strength of the obtained rubber laminate can be further increased while improving the processability of the epihalohydrin rubber composition.

  The Mooney viscosity [ML1 + 4 (100 ° C.)] of the epihalohydrin rubber is preferably 10 to 200, more preferably 20 to 150, and further preferably 30 to 100. By setting the Mooney viscosity within the above range, the mechanical strength of the obtained rubber laminate can be further increased while improving the processability of the epihalohydrin-based rubber composition.

  The epihalohydrin rubber used in the present invention can be obtained by ring-opening polymerization of each of the above monomers by a solution polymerization method or a solvent slurry polymerization method. The polymerization catalyst is not particularly limited as long as it is a catalyst for general epihalohydrin rubber. Examples of the polymerization catalyst include a catalyst in which water and acetylacetone are reacted with organic aluminum (Japanese Patent Publication No. 35-15797), and a catalyst in which triisobutylaluminum is reacted with phosphoric acid and triethylamine (Japanese Patent Publication No. 46-27534). , A catalyst obtained by reacting triisobutylaluminum with an organic acid salt of diazabiacycloundecene and phosphoric acid (Japanese Patent Publication No. 56-51171), a catalyst comprising a partial hydrolyzate of aluminum alkoxide and an organozinc compound (JP-B-43-2945), a catalyst comprising an organic zinc compound and a polyhydric alcohol (JP-B-45-7751), a catalyst comprising dialkylzinc and water (JP-B-36-3394), an organic A catalyst comprising a tin compound (JP-A-2000-63656) is exemplified.

  Examples of the polymerization solvent include aromatic hydrocarbons such as benzene and toluene; linear saturated hydrocarbons such as n-pentane and n-hexane; and cyclic saturated hydrocarbons such as cyclopentane and cyclohexane. Further, the polymerization reaction can be carried out usually at 0 to 100 ° C, preferably 30 to 80 ° C, by any method such as a batch system, a semi-batch system, and a continuous system.

  When the epihalohydrin rubber used in the present invention is a copolymer, it may be any copolymer type of block copolymer or random copolymer, but in particular, when ethylene oxide is used as the monomer, the random copolymer may be used. It is more preferable to lower the crystallinity of polyethylene oxide and to hardly impair the rubber elasticity.

<Silica>
The silica is not particularly limited, and includes, for example, dry silica, wet silica, colloidal silica, and precipitated silica. Dry silica is preferred.

  Further, as the silica, a surface-treated silica surface-treated with a surface-treating agent is preferable, and by using the surface-treated silica, the obtained rubber laminate is made to have more excellent compression set resistance and elongation at break. Can be. The surface treatment agent used at this time is not particularly limited, but from the viewpoint that the effect of improving compression set resistance and elongation at break can be further enhanced, a surface capable of introducing a non-reactive group to the silica surface. Treatment agents are preferred. That is, it is preferable to use silica surface-treated with a non-reactive group. Here, the non-reactive group is a group that is non-reactive (or inactive) with respect to the epihalohydrin rubber (particularly, a halogen atom contained in the epihalohydrin rubber). In addition, for example, a group that reacts with an epihalohydrin-based rubber via a cross-linking agent including a quinoxaline-based cross-linking agent can also be said to exhibit reactivity with the epihalohydrin-based rubber. Even if the group does not directly react with the system rubber, a group that reacts with the epihalohydrin rubber through a cross-linking agent including a quinoxaline-based cross-linking agent does not correspond to a non-reactive group. Examples of the surface treatment agent capable of introducing a non-reactive group include a coupling agent having a non-reactive group and a silicone oil having a non-reactive group.

  Examples of such a non-reactive group include an alkyl group, an alkoxy group, an aryl group, an N, N-disubstituted amino group, and a cyano group. Among these, the silica surface can be hydrophobized, whereby the affinity between the epihalohydrin rubber and the silica surface-treated with a non-reactive group can be improved, and as a result, From the viewpoint that the compression set resistance and the elongation at break can be more highly balanced, an alkyl group and an aryl group are more preferred, and an alkyl group is even more preferred. Further, as the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group and the like are preferable, and a methyl group is particularly preferable.

The nitrogen adsorption specific surface area (BET specific surface area) of the silica used in the present invention measured by the BET method is not particularly limited, but is preferably 50 to 300 m ² / g, more preferably 80 to ²⁰⁰ m ² / g, and furthermore preferably 80~140m ² / g, particularly preferably 80 to 120 ² / g. When the nitrogen adsorption specific surface area of the silica is in the above range, the obtained rubber laminate can have excellent compression set resistance, which is preferable. The nitrogen adsorption specific surface area of the non-reactive group surface-treated silica can be measured by a BET method according to ASTM D3037-81.

  The number average primary particle size of the silica used in the present invention is not particularly limited, but is preferably 7 to 30 nm, more preferably 13 to 20 nm, and further preferably 14 to 18 nm.

  The pH of the silica used in the present invention is not particularly limited, but is preferably 10 or less. In the case of silica obtained by a dry method, the pH is preferably 3 to 10, more preferably 3 to 10. -8, particularly preferably 3.5-6. In the case of silica obtained by a wet method, the pH is preferably 3 to 10, more preferably 4 to 8, and particularly preferably 6 to 8.

  The content of silica in the epihalohydrin rubber composition used in the present invention is preferably 5 to 100 parts by weight, more preferably 10 to 80 parts by weight, and still more preferably 15 to 60 parts by weight, per 100 parts by weight of the epihalohydrin rubber. Parts by weight. By setting the content of silica within the above range, the obtained rubber laminate can be made more excellent in balance between resistance to compression set and elongation at break.

<Quinoxaline crosslinking agent>
The quinoxaline-based cross-linking agent is not particularly limited, and may be a compound having a quinoxaline structure and a reactivity with a chlorine atom contained in the epihalohydrin-based rubber. For example, 2,3-dimercapto Quinoxaline, quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline-2,3-dithiocarbonate, 5,8-dimethylquinoxaline-2,3-dithiocarbonate and the like. Among these, 6-methylquinoxaline- 2,3-dithiocarbonate is preferably used.

  The content of the quinoxaline-based crosslinking agent in the epihalohydrin-based rubber composition used in the present invention is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the epihalohydrin-based rubber. And more preferably 1.0 to 5 parts by weight. By setting the content of the quinoxaline-based crosslinking agent in the above range, the obtained rubber laminate can have more excellent compression set resistance and elongation at break.

<Acid acceptor>
As the acid acceptor, those generally used as an acid acceptor at the time of molding and crosslinking of an epihalohydrin rubber can be used without limitation. Examples of the acid acceptor include magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, calcium carbonate, calcium borate, zinc stearate, calcium phthalate, calcium phosphite, Zinc oxide, calcium silicate, magnesium silicate, magnesium borate, magnesium metaborate, calcium metaborate, oxides, hydroxides, carbonates, carboxylate salts of Group 2 metals such as barium metaborate, Silicate, borate, phosphite, metaborate; tin oxide, basic tin carbonate, tin stearate, basic tin phosphite, basic tin sulfite, silicon oxide, silicon stearate; Group metal oxides, basic carbonates, basic carboxylates, basic phosphites, basic suboxides Salt; hydrotalcites; aluminum hydroxide gel compound; and the like. Among these, hydrotalcites are preferable, and hydrotalcites represented by the following formula are particularly preferable.
_{Mg x Al y (OH) 2x} + 3y-2 CO 3 · mH 2 O
(In the above formula, x = 1 to 10, y = 1 to 5, and m represents 0 or a positive real number.)

  The content of the acid acceptor in the epihalohydrin rubber composition used in the present invention is preferably 1 to 30 parts by weight, more preferably 3 to 20 parts by weight, and still more preferably 5 parts by weight, based on 100 parts by weight of the epihalohydrin rubber. １５15 parts by weight. By setting the content of the acid acceptor in the above range, the obtained rubber laminate can have more excellent compression set resistance and elongation at break.

<Sulfur atom-containing silane coupling agent>
The sulfur atom-containing silane coupling agent is not particularly limited as long as it is a compound containing a sulfur atom and acting as a silane coupling agent.

  Examples of the sulfur atom-containing silane coupling agent include 3-mercaptopropyltrimethoxysilane, 3-mercaptomethyltrimethoxysilane, 3-mercaptomethyltriethoxysilane, 3-mercaptohexamethyldisilazane, 3-octanoylthio-1- Propyl-triethoxysilane, bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, 3-trimethoxysilylpropyldimethylthiocarbamyltetrasulfide, and 3-tri Methoxysilylpropyl benzothiazyl tetrasulfide and the like. Among these, the obtained rubber laminate can have a higher compression set resistance, and can improve the adhesive strength between the pyrohalohydrin-based rubber layer (A) and the fluororubber layer (B). From the viewpoint of being able to further increase, a silane coupling agent containing a mercapto group is preferable, and 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropyltriethoxysilane are more preferable.

  In the epihalohydrin rubber composition used in the present invention, the content of the sulfur atom-containing silane coupling agent is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the epihalohydrin rubber. 7 parts by weight, more preferably 0.3 to 5 parts by weight. By setting the content of the sulfur atom-containing silane coupling agent in the above range, the obtained rubber laminate has resistance to compression set, and adhesion between the pyrohalohydrin-based rubber layer (A) and the fluororubber layer (B). Sex can be further enhanced.

<Other compounding agents to be added to the epihalohydrin rubber composition>
The epihalohydrin-based rubber composition used in the present invention preferably further contains carbon black in addition to the above components. Examples of carbon black include furnace black, acetylene black, thermal black, channel black, austin black, graphite, and the like. These can be used alone or in combination.

  In the epihalohydrin rubber composition used in the present invention, the content of carbon black is preferably 1 to 100 parts by weight, more preferably 5 to 70 parts by weight, and still more preferably 10 to 100 parts by weight, based on 100 parts by weight of the epihalohydrin rubber. 50 parts by weight.

  The epihalohydrin rubber composition used in the present invention includes natural rubber, polybutadiene rubber, polyisoprene rubber, acrylic rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, and the like, as long as the effects of the present invention are not impaired. Rubber; thermoplastic elastomers such as olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, polyurethane-based thermoplastic elastomer; polyvinyl chloride, cumarone resin And a resin such as a phenolic resin. The compounding amount of these rubbers, thermoplastic elastomers or resins is preferably at most 30 parts by weight, particularly preferably at most 10 parts by weight, based on 100 parts by weight of the epihalohydrin rubber.

  Further, the epihalohydrin rubber composition used in the present invention may contain other compounding agents usually compounded in known rubbers, in addition to the compounding agents described above. Examples of such a compounding agent include, but are not particularly limited to, a plasticizer; a reinforcing agent; a crosslinking agent other than a quinoxaline-based crosslinking agent; a crosslinking retarder; a crosslinking accelerator; an activator; a processing aid; Absorbent; light stabilizer; tackifier; surfactant; conductivity-imparting agent; electrolyte substance; colorant (dye / pigment); flame retardant;

  The epihalohydrin rubber composition used in the present invention is obtained by adding silica, a quinoxaline-based cross-linking agent, an acid acceptor, and a sulfur atom-containing silane coupling agent to an epihalohydrin rubber, and various compounding agents used as required. It can be prepared by blending and kneading according to the method. For example, after kneading a compounding agent excluding a quinoxaline-based crosslinking agent and a crosslinking accelerator used as needed and an epihalohydrin-based rubber, a quinoxaline-based crosslinking agent and a crosslinking accelerator used as needed are mixed with the mixture. Thus, an epihalohydrin rubber composition can be obtained. In mixing and kneading, for example, kneading and molding may be performed using one or a plurality of arbitrary kneading and molding machines such as a kneader, a Banbury, an open roll, a calender roll, and an extruder. The kneading temperature of the epihalohydrin rubber and the additives excluding the quinoxaline-based crosslinking agent and the crosslinking accelerator used as necessary and the epihalohydrin-based rubber are preferably from 20 to 200 ° C, more preferably from 20 to 150 ° C. The temperature is preferably from 30 seconds to 30 minutes, and the mixing temperature of the kneaded product with the quinoxaline-based crosslinking agent and the crosslinking accelerator is preferably 100 ° C or lower, more preferably 0 to 80 ° C.

<Fluorine rubber composition>
The fluororubber composition constituting the fluororubber layer (B) of the rubber laminate of the present invention contains a fluororubber and a polyol-based crosslinking agent.

  As the fluororubber, a homopolymer rubber of a fluorinated unsaturated monomer, a copolymer rubber of a fluorinated unsaturated monomer or another monomer copolymerizable with a fluorinated unsaturated monomer And copolymer rubber. Examples of the fluorine-containing unsaturated monomer for forming a fluororubber include vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, pentafluoropropylene, trifluoroethylene, trifluorochloroethylene, vinyl fluoride, and perfluoromethyl vinyl ether. And perfluoroethyl vinyl ether, and crosslinkable monomers such as brominated and / or iodinated unsaturated fluorohydrocarbons. Other monomers copolymerizable with the fluorine-containing unsaturated monomer include ethylene and propylene.

  Specific examples of the fluororubber include binary copolymer rubbers such as vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-perfluoromethylvinyl ether copolymer, and vinylidene fluoride. And a terpolymer rubber of a ride-hexafluoropropylene-tetrafluoroethylene copolymer.

  Further, the polyol-based cross-linking agent is not particularly limited, but from the viewpoint that the adhesive strength between the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) in the obtained rubber laminate can be further increased, Hydroxy compounds are preferred, and polyhydroxy aromatic compounds are more preferred.

  The polyhydroxy aromatic compound is not particularly limited, and for example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes referred to as “bisphenol A”), 2,2-bis (4-hydroxy Phenyl) perfluoropropane (hereinafter sometimes referred to as “bisphenol AF”), resorcinol, 1,3-dihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis (4-hydroxyphenyl) butane, 4,4-bis (4-hydroxyphenyl) Valeric acid, 2,2-bis (4-hydroxyphenyl) te Lafluorodichloropropane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylketone, tri (4-hydroxyphenyl) methane, 3,3 ', 5,5'-tetrachlorobisphenol A, 3,3 ', 5,5'-Tetrabromobisphenol A and the like. In addition, these polyhydroxy aromatic compounds may be alkali metal salts, alkaline earth metal salts, or the like.

  The content of the polyol-based crosslinking agent in the fluororubber composition used in the present invention is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 6 parts by weight, based on 100 parts by weight of the fluororubber. Preferably, it is 1 to 4 parts by weight.

  Further, the fluororubber composition used in the present invention may contain other compounding agents usually compounded in known rubbers, in addition to the polyol-based crosslinking agent. Such a compounding agent is not particularly limited, but includes, for example, a plasticizer; a reinforcing agent; a crosslinking agent other than a polyol-based crosslinking agent; a crosslinking retarder; a crosslinking accelerator; an acid acceptor; an activator; Inhibitors; ultraviolet absorbers; light stabilizers; tackifiers; surfactants; conductivity-imparting agents; electrolyte substances; coloring agents (dyes / pigments); flame retardants;

  The fluororubber composition used in the present invention can be prepared by mixing and kneading the fluororubber with a polyol-based crosslinking agent and various compounding agents used as required by a desired method. In mixing and kneading, for example, kneading and molding may be performed using one or a plurality of arbitrary kneading and molding machines such as a kneader, a Banbury, an open roll, a calender roll, and an extruder.

<Rubber laminate>
The rubber laminate of the present invention is a laminate including the epihalohydrin-based rubber layer (A) composed of the above-described epihalohydrin-based rubber composition and a fluororubber layer (B) composed of the fluororubber composition.

  The rubber laminate of the present invention may be any one provided with an epihalohydrin-based rubber layer (A) composed of the above-described epihalohydrin-based rubber composition and a fluororubber layer (B) composed of the fluororubber composition. It is preferable that the rubber layer (A) is a layer composed of a crosslinked product of an epihalohydrin rubber composition, and the fluororubber layer (B) is a layer composed of a crosslinked product of a fluororubber composition. Further, the lamination mode of the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) is not particularly limited, but it is preferable that these are cross-linked and adhered.

  The rubber laminate of the present invention can be produced, for example, by the following method. That is, first, the epihalohydrin-based rubber composition and the fluororubber composition described above are each separately separated by a known method such as press molding, roll molding, or extrusion molding, and the thickness is preferably 0.1 to 5 mm, more preferably It is formed in a non-crosslinked state into a sheet (sheet of acrylic rubber layer (A), sheet of fluororubber layer (B)) having an arbitrary area of 0.5 to 3 mm. Next, the obtained sheets are brought into contact with each other, and are press-heated and cross-linked using a hot press or a vulcanizer to bond them, whereby the rubber laminate of the present invention can be obtained.

  Alternatively, a method in which the epihalohydrin-based rubber composition and the fluororubber composition described above are formed into a laminated tube shape in an uncrosslinked state by a layer extrusion method, and then pressurized and heated and crosslinked using a vulcanizing can to bond them. May be adopted.

Hot pressing is usually performed at a temperature of 140 to 200 ° C. under a pressure of 0.2 to 15 MPa for 5 to 60 minutes. In the case of using a vulcanizing can, it is usually performed at a temperature of 130 to 160 ° C. under a pressure of 0.18 MPa for 30 to 120 minutes.
Further, the obtained rubber laminate may be further heat-treated (post-cured).

  It should be noted that the rubber laminate of the present invention is not limited to a form in which the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) are laminated one by one, as long as they have a portion where these are laminated. One or both of these may be formed as a plurality of layers. Further, another layer made of another material may be provided. As such other material, an appropriate material may be selected according to the required properties, the intended use, etc., for example, acrylic rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene rubber, and polyvinyl chloride. And chlorosulfonated polyethylene rubber.

  The rubber laminate of the present invention thus obtained has an excellent balance between compression set resistance and elongation at break, has excellent heat resistance, and has an epihalohydrin rubber layer (A) and a fluoro rubber layer ( It has excellent adhesion to B). For this reason, the rubber laminate of the present invention takes advantage of these characteristics to provide, for example, O-rings, gaskets, packings, oil seals, bearing seals, and the like in a wide range of fields such as transportation machinery such as automobiles, general equipment, and electrical equipment. Hose such as oil tubes, fuel hoses, air hoses, turbo air hoses, PCV hoses, inlet hoses; industrial belts such as transmission belts and endless belts; cushioning materials, vibration damping materials; It is useful as sheets, boots, dust covers, and the like. Among them, the rubber laminate of the present invention can be particularly suitably used for hose applications, especially for fuel hose applications.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The “parts” in each example are based on weight unless otherwise specified.
Various physical properties were evaluated according to the following methods.

[Mooney viscosity of epihalohydrin rubber composition]
Mooney viscosity (ML1 + 4, 100 ° C.) was measured at 100 ° C. according to JIS K6300.

[Normal physical properties (tensile strength, elongation at break, hardness, 100% tensile stress) of crosslinked product of epihalohydrin rubber]
The epihalohydrin-based rubber composition was placed in a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm, and press-molded at 160 ° C. for 30 minutes while applying a pressure of 10 MPa to obtain a sheet-like primary crosslinked product. Next, the obtained primary cross-linked product was transferred to a gear oven and subjected to secondary cross-linking at 150 ° C. for 4 hours to obtain a sheet-like rubber cross-linked product. Then, a test piece was prepared by punching out the obtained sheet-like rubber cross-linked product with a No. 3 dumbbell, and using the obtained test piece, in accordance with JIS K6251, the tensile strength and breaking elongation of the rubber cross-linked product. And 100% tensile stress, and the hardness of the rubber crosslinked product was measured using a durometer hardness tester (type A) according to JIS K6253.

[Heat Aging Test of Crosslinked Epihalohydrin Rubber]
A heat aging test was performed on a test piece (a test piece obtained by punching out a sheet-like rubber cross-linked product with a No. 3 dumbbell) in the same manner as in the measurement of the above-mentioned normal physical properties. The heat aging test was performed at 150 ° C. for 158 hours in accordance with JIS K6257 (2010), and the tensile strength, elongation at break, hardness, and 100% tensile stress were measured. The evaluation of tensile strength, elongation at break, and 100% tensile stress was determined as the rate of change of the measured values after the heat aging test with respect to the measured values obtained in the above-described measurement of the physical properties in the normal state. The evaluation of the hardness was determined as the amount of change in the measured value after the heat aging test with respect to the measured value obtained in the measurement of the physical properties in the normal state.

[Compression set test of crosslinked epihalohydrin rubber]
The epihalohydrin-based rubber composition was cross-linked by pressing at a temperature of 160 ° C. for 30 minutes using a mold to obtain a columnar primary cross-linked product having a diameter of 29 mm and a height of 12.5 mm. Next, the obtained primary cross-linked product was further subjected to secondary cross-linking by heating at 150 ° C. for 4 hours in a gear oven to obtain a cylindrical test piece. Then, using the obtained test piece, in accordance with JIS K6262, the test piece was placed in an environment of 135 ° C. for 22 hours in a state of being compressed by 25%, and the compression set was measured. The smaller the value, the more excellent the compression set resistance.

[Peeling test of rubber laminate]
A peel test was performed on the rubber laminate according to JIS K6256 to evaluate the adhesiveness between both layers constituting the rubber laminate. Specifically, the obtained rubber laminate was punched into a strip having a width of 25.4 mm and a length of 100 mm, and both ends thereof were gripped by an air chuck of a tensile tester, and were rotated at a speed of 50 mm / min at a speed of 180 °. A peeling test was performed, and the load at the time of peeling was read by a load cell of a tensile tester, and the load was determined by a peel strength _TF (N / mm). It can be determined that the higher the peel strength, the better the adhesiveness.

[Production Example 1, Production of polymerization catalyst]
The sealed pressure-resistant glass container was replaced with nitrogen, and 200 parts of toluene and 60 parts of triisobutylaluminum were supplied. After cooling this glass container by immersing it in ice water, 230 parts of diethyl ether was added and stirred. Next, 13.6 parts of phosphoric acid was added while cooling with ice water, followed by further stirring. At this time, the internal pressure of the container was increased due to the reaction between triisobutylaluminum and phosphoric acid, so depressurization was performed as appropriate. Next, the obtained reaction mixture was aged for 1 hour in a hot water bath at 60 ° C. to obtain a catalyst solution.

[Production Example 2, Production of Epichlorohydrin Rubber (a-1)]
An autoclave was charged with 250 parts of epichlorohydrin, 16 parts of ethylene oxide, and 279 parts of toluene. The internal solution was heated to 60 ° C. while stirring under a nitrogen atmosphere, and 10 parts of the catalyst solution obtained above was added and reacted. Started. Next, a solution prepared by dissolving 103 parts of ethylene oxide in 150 parts of toluene was continuously added at a constant rate over 5 hours from the start of the reaction. Also, every 30 minutes after the start of the reaction, 7 parts of the catalyst solution were added over 5 hours. Then, 15 parts of water was added and stirred to terminate the reaction. Further, 45 parts of a 5% by weight toluene solution of 4,4′-thiobis- (6-tert-butyl-3-methylphenol) was added as an antioxidant, and the mixture was stirred. After removing the toluene by performing steam stripping and removing the supernatant water, vacuum drying was performed at 60 ° C. to obtain 369 parts of epichlorohydrin rubber (a-1). The monomer composition ratio of this epichlorohydrin rubber (a-1) was 50 mol% of an epichlorohydrin monomer unit and 50 mol% of an ethylene oxide monomer unit as a result of measurement by ¹ H-NMR. Was. The Mooney viscosity of the obtained epichlorohydrin rubber (a-1) was 69.

[Production Example 3, production of epichlorohydrin rubber (a-2)]
100 parts of epichlorohydrin and 560 parts of toluene were put into an autoclave, the temperature of the internal solution was raised to 60 ° C. while stirring under a nitrogen atmosphere, and 10 parts of the catalyst solution obtained above was added to start the reaction. Every 30 minutes after the start of the reaction, 7 parts of the catalyst solution was added over 5 hours. Then, 15 parts of water was added and stirred to terminate the reaction. Further, 45 parts of a 5% by weight toluene solution of 4,4′-thiobis- (6-tert-butyl-3-methylphenol) was added as an antioxidant, and the mixture was stirred. The toluene was removed by steam stripping, and the supernatant water was removed, followed by vacuum drying at 60 ° C. to obtain 100 parts of epichlorohydrin rubber (a-2). The monomer composition ratio of this epichlorohydrin rubber (a-2) was measured by ¹ H-NMR, and as a result, was 100 mol% of epichlorohydrin monomer units. The Mooney viscosity of the obtained epichlorohydrin rubber (a-2) was 75.

[Production Example 4, production of epichlorohydrin rubber (a-3)]
265.2 parts of epichlorohydrin, 13.0 parts of allyl glycidyl ether, 9.76 parts of ethylene oxide, and 3250 parts of toluene were put into an autoclave, and the internal solution was heated to 60 ° C. while stirring under a nitrogen atmosphere. The reaction was started by adding 8 parts of the catalyst solution obtained in the above. Next, a solution prepared by dissolving 60.91 parts of ethylene oxide in 300 parts of toluene from the start of the reaction was continuously added at a constant rate over 5 hours. Also, every 30 minutes after the start of the reaction, 7 parts of the catalyst solution were added over 5 hours. Then, 15 parts of water was added and stirred to terminate the reaction. Further, 45 parts of a 5% by weight toluene solution of 4,4′-thiobis- (6-tert-butyl-3-methylphenol) was added as an antioxidant, and the mixture was stirred. The toluene was removed by steam stripping, the supernatant water was removed, and then vacuum drying was performed at 60 ° C. to obtain 349 parts of epichlorohydrin rubber (a-3). The monomer composition ratio of this epichlorohydrin rubber (a-3) was measured by ¹ H-NMR. As a result, 62.5 mol% of epichlorohydrin monomer units and 35 mol% of ethylene oxide monomer units were obtained. And allyl glycidyl ether monomer unit was 2.5 mol%. The Mooney viscosity of the obtained epichlorohydrin rubber (a-3) was 69.

[Example 1]
[Preparation of Epihalohydrin Rubber Composition]
30 parts of the epichlorohydrin rubber (a-1) obtained in Production Example 2 and 70 parts of the epichlorohydrin rubber (a-2) obtained in Production Example 3 were put into an open roll at 40 ° C., and then , 20 parts of HAF carbon black (product name "Seast 3", manufactured by Tokai Carbon Co., Ltd.), dimethylsilyl treated silica (product name "Aerosil R972V", manufactured by EVONIC, dry silica treated with dimethyldichlorosilane, BET specific surface area: 110 m) ² / g, pH: 3.5-5.5, apparent specific gravity: about 90 g / L) 20 parts, polyetherester plasticizer (product name "ADEKASIZER RS735", manufactured by ADEKA) 5 parts, ester wax (Product name "Splendor R300", Kao Corporation, processing aid) 3 parts, hydrotalcite (Product name "DHT-4A", Kyowa Chemical Industry Co., Ltd.) 1 part of polyethylene glycol 400 (activator), 3-mercaptopropyltrimethoxysilane (product name "KBM-803", product of Shin-Etsu Silicone, silane coupling agent containing sulfur atom) 1 Part, 2-mercaptobenzimidazole (product name "Nocrack MB", manufactured by Ouchi Shinko Chemical Co., Ltd., antioxidant) 0.5 part, 4,4'-di- (α, α-dimethylbenzyl) diphenylamine (product Name: "Nocrack CD", 1 part of Ouchi Shinko Chemical Co., Ltd., anti-aging agent), 1 part of copper dimethyldithiocarbamate (product name "Noxeller TTCU", product of Ouchi Shinko Chemical Co., anti-aging agent), 1 part, N- 1 part of (cyclohexylthio) phthalimide (product name "RETARDER CTP", manufactured by Ouchi Shinko Chemical Co., Ltd., crosslinking retarder), 1,8-diazabicyclo [5.4] .0] 1 part of a phenol salt of undec-7-ene (DBU) (product name "U-CAT SA831", manufactured by San Apro, 42% by weight of DBU, crosslinking accelerator), and 6-methylquinoxaline-2,3-dithio An epihalohydrin-based rubber composition was prepared by charging 1.2 parts of carbonate (quinoxaline-based crosslinking agent), kneading and mixing for 10 minutes.
Using the obtained epihalohydrin-based rubber composition, measurements and tests of Mooney viscosity, normal physical properties (tensile strength, elongation at break, hardness, 100% tensile stress), heat aging test, and compression set were performed. Was. Table 1 shows the results.

[Preparation of fluororubber composition]
100 parts of a fluororubber containing a polyol-based crosslinker (product name "VITON A-401C", manufactured by Chemers Co., Ltd., containing bisphenol AF as a polyol-based crosslinker) was mixed with 100 parts of MT carbon black (product name "Thermax MT"). ", 30 parts of magnesium oxide (product name" Kyowa Mag 150 ", manufactured by Kyowa Chemical Industry Co., Ltd., acid acceptor), and 30 parts of calcium hydroxide (product name" Cardic # 1000 ", Omi) 6 parts of an acid acceptor (manufactured by Chemical Industry Co., Ltd.) were added and kneaded with an open roll to obtain a fluororubber composition.

[Manufacture of rubber laminate]
The epihalohydrin-based rubber composition and the fluororubber composition obtained above were each kneaded with an open roll, dispensed into a sheet having a uniform thickness of about 2 mm, and formed into a 6 cm × 10 cm square. A sheet-shaped molded body was obtained. Next, the obtained sheet-shaped molded bodies were laminated, placed in a mold having a length of 6 cm, a width of 10 cm, and a depth of 0.4 cm, and cross-linked at 160 ° C. for 30 minutes while applying a pressure of 50 kg / cm ^2. Further, secondary cross-linking (secondary cross-linking conditions: 150 ° C., 4 hours) was performed to produce a rubber laminate. At this time, in order to perform the above-described peeling test, a portion where both sheets were not bonded was formed by previously sandwiching cellophane paper in a portion to be gripped by the air chuck during the peeling test. Then, a peeling test was performed using the obtained rubber laminate according to the above method. Table 1 shows the results.

[Example 2]
When preparing the epihalohydrin rubber composition, bis (3- (triethoxysilyl) propyl) tetrasulfide (product name “Si69”, manufactured by Evonik Industries, Inc.) was used instead of 1 part of 3-mercaptopropyltrimethoxysilane. An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained in the same manner as in Example 1 except that 1 part of an atom-containing silane coupling agent) was used and evaluated in the same manner. Table 1 shows the results.

[Example 3]
When preparing the epihalohydrin rubber composition, the amount of the epichlorohydrin rubber (a-1) obtained in Production Example 2 was changed from 30 parts to 40 parts, and the epichlorohydrin rubber obtained in Production Example 3 ( a-2) An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained and evaluated in the same manner as in Example 1 except that the amount was changed from 70 parts to 60 parts. Table 1 shows the results.

[Example 4]
When preparing the epihalohydrin rubber composition, the amount of the epichlorohydrin rubber (a-1) obtained in Production Example 2 was changed from 30 parts to 50 parts, and the epichlorohydrin rubber obtained in Production Example 3 ( a-2) An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained in the same manner as in Example 1 except that the parts were changed from 70 parts to 50 parts, respectively, and were similarly evaluated. Table 1 shows the results.

[Example 5]
When preparing the epihalohydrin rubber composition, the amount of the epichlorohydrin rubber (a-1) obtained in Production Example 2 was changed from 30 parts to 70 parts, and the epichlorohydrin rubber obtained in Production Example 3 ( a-2) An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained in the same manner as in Example 1 except that the parts were changed from 70 parts to 30 parts, respectively, and were similarly evaluated. Table 1 shows the results.

[Example 6]
When preparing the epihalohydrin rubber composition, instead of the epichlorohydrin rubber (a-1) and epichlorohydrin rubber (a-2) obtained in Production Example 2, epichlorohydrin rubber obtained in Production Example 4 was used. An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained in the same manner as in Example 1 except that 100 parts of hydrin rubber (a-3) was used, and evaluated in the same manner. Table 1 shows the results.

[Comparative Example 1]
In preparing the epihalohydrin rubber composition, the amount of the epichlorohydrin rubber (a-2) obtained in Production Example 3 was changed from 70 parts to 100 parts, and the epichlorohydrin rubber (a-2) obtained in Production Example 2 was used. An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained and evaluated in the same manner as in Example 1 except that the chlorohydrin rubber (a-1) was not used. Table 2 shows the results.

[Comparative Example 2]
When preparing the epihalohydrin rubber composition, the amount of the epichlorohydrin rubber (a-1) obtained in Production Example 2 was changed from 30 parts to 100 parts, and the epichlorohydrin rubber (a-1) obtained in Production Example 3 was used. An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained and evaluated in the same manner as in Example 1 except that the chlorohydrin rubber (a-2) was not used. Table 2 shows the results.

[Comparative Example 3]
An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were prepared in the same manner as in Example 1 except that 3-mercaptopropyltrimethoxysilane was not used when preparing the epihalohydrin-based rubber composition. Obtained and evaluated similarly. Table 2 shows the results.

[Comparative Example 4]
When preparing an epihalohydrin-based rubber composition, 3-glycidyloxypropyltrimethoxysilane (product name "Dynasylan GLYMO", manufactured by Evonik Industries, Inc., containing no sulfur atom) instead of 1 part of 3-mercaptopropyltrimethoxysilane An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained in the same manner as in Example 1 except that 1 part of (silane coupling agent) was used, and evaluated in the same manner. Table 2 shows the results.

[Comparative Example 5]
When preparing an epihalohydrin-based rubber composition, 3-aminopropyltriethoxysilane (product name "Dynasylan AMEO", manufactured by Evonik Industries, Inc., a sulfur-free silane) is used instead of 1 part of 3-mercaptopropyltrimethoxysilane. An epihalohydrin-based rubber composition, a fluororubber composition, and a rubber laminate were obtained in the same manner as in Example 1 except that 1 part of (coupling agent) was used, and similarly evaluated. Table 2 shows the results.

As shown in Tables 1 and 2, an epihalohydrin-based rubber containing 55 to 90 mol% of an epihalohydrin monomer unit and 10 to 45 mol% of an alkylene oxide monomer unit, silica, a quinoxaline-based crosslinking agent, An epihalohydrin-based rubber layer (A) comprising an epihalohydrin-based rubber composition containing an acid acceptor and a sulfur atom-containing silane coupling agent; and a fluororubber composition containing a fluororubber and a polyol-based crosslinking agent. The rubber laminate provided with the fluororubber layer (B) had high peel strength and excellent adhesion between the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) (Examples 1 to 6). ).
Further, a crosslinked product of an epihalohydrin rubber obtained by using the epihalohydrin rubber composition forming the epihalohydrin rubber layer (A) has an excellent balance between compression set resistance and elongation at break, and has excellent heat resistance. Thus, a rubber laminate comprising an epihalohydrin-based rubber layer (A) and a fluororubber layer (B) is also excellent in balance between compression set resistance and elongation at break, and has excellent heat resistance. It can be said that there is (Examples 1 to 6).

On the other hand, when an epihalohydrin rubber which does not contain an alkylene oxide monomer unit is used as the epihalohydrin rubber constituting the epihalohydrin rubber composition, the adhesive property between the epihalohydrin rubber layer (A) and the fluororubber layer (B) is reduced. (Comparative Example 1).
When the epihalohydrin-based rubber constituting the epihalohydrin-based rubber composition contains too little epihalohydrin monomer unit, the tensile strength after heat resistance is low, and the heat resistance is poor. As a result, the compression set was also increased (Comparative Example 2).
When the epihalohydrin-based rubber composition does not contain a sulfur atom-containing silane coupling agent, the adhesion between the epihalohydrin-based rubber layer (A) and the fluororubber layer (B) is poor, and As a result, the compression set was also increased (Comparative Example 3).

Furthermore, when 3-glycidyloxypropyltrimethoxysilane (epoxy group-containing silane coupling agent) as a silane coupling agent containing no sulfur atom is blended with the epihalohydrin rubber composition, the hardness and compression set are reduced. The result was higher (Comparative Example 4).
Further, when 3-aminopropyltriethoxysilane (amino group-containing silane coupling agent) as a silane coupling agent containing no sulfur atom is added to the epihalohydrin-based rubber composition, the epihalohydrin-based rubber layer (A) And the fluororubber layer (B) were inferior in adhesiveness, resulting in a low elongation at break (Comparative Example 5).

Claims (4)

An epihalohydrin-based rubber containing 55 to 90 mol% of an epihalohydrin monomer unit and 10 to 45 mol% of an alkylene oxide monomer unit, silica, a quinoxaline-based crosslinking agent, an acid acceptor, and a sulfur atom-containing silane cup. An epihalohydrin-based rubber layer (A) comprising an epihalohydrin-based rubber composition containing a ring agent;
A rubber laminate comprising a fluororubber layer (B) made of a fluororubber composition containing a fluororubber and a polyol-based crosslinking agent.   The rubber laminate according to claim 1, wherein the sulfur atom-containing silane coupling agent is a mercapto group-containing silane coupling agent.   The epihalohydrin-based rubber layer (A) is a layer composed of a crosslinked product of the epihalohydrin-based rubber composition, and the fluororubber layer (B) is a layer composed of a crosslinked product of the fluororubber composition. Or the rubber laminate according to 2.   A hose using the rubber laminate according to claim 3.