JP6167692B2 - Rubber laminate - Google Patents

Description

  The present invention relates to a rubber laminate obtained by cross-linking and bonding an acrylic rubber layer made of an acrylic rubber composition and a fluororubber layer made of a fluororubber composition, and more specifically, has excellent heat resistance and is an acrylic rubber layer. It is related with the rubber laminated body excellent in the cross-linking adhesiveness between a fluororubber layer.

  Gasohol, which is a mixture of gasoline and alcohol, is attracting attention as a fuel for automobiles due to the recent petroleum situation. As a material for a gas hose fuel hose, fluororubber having gasohol resistance is used. Fluoro rubber has excellent performance in heat resistance, oil resistance, solvent resistance, chemical resistance, etc. Especially among fluorinated rubbers, those of terpolymers have excellent gasohol resistance. Are known.

  In recent years, vehicles equipped with a turbocharger system have been widely used in response to exhaust gas regulations. The air hose used in the turbocharger system uses fluororubber having heat resistance, oil resistance, and the like because deteriorated oil and fuel mist flow with hot air.

  However, on the other hand, since fluoro rubber is expensive, when manufacturing a fuel hose or air hose, fluoro rubber is used as the thin inner layer, and the outer layer is made of rubber with excellent cold resistance and weather resistance. Structure is adopted.

  As a fuel hose having such a laminated structure, for example, in Patent Document 1, a fluorine rubber layer containing iodine-containing fluorine rubber, an organic peroxide crosslinking agent, triallyl isocyanurate and ethylene glycol dimethacrylate, and epichlorohydrin- Ethylene oxide copolymer rubber (ECO), blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride (NBR-PVC), acrylic rubber (ACM), ethylene-acrylic rubber (AEM), chlorosulfonated polyethylene (CSM), etc. A fuel hose formed by laminating other rubber layers is disclosed. In Patent Document 1, an epoxy group-containing acrylic rubber (Nipol AR31) is disclosed as a specific example of an acrylic rubber (ACM) constituting a layer made of other rubber. However, none of the rubbers constituting the layers composed of other rubbers disclosed in Patent Document 1 has sufficient heat resistance, and the excellent heat resistance of fluororubber cannot be fully utilized. There was a problem that the field of application would be limited.

JP 2007-271077 A

  The present invention has been made in view of such a situation, and in a rubber laminate formed by crosslinking and bonding an acrylic rubber layer made of an acrylic rubber composition and a fluororubber layer made of a fluororubber composition, An object of the present invention is to provide a rubber laminate having improved properties and excellent cross-linking adhesion between an acrylic rubber layer and a fluororubber layer.

  As a result of intensive studies to achieve the above object, the present inventors have formed an acrylic rubber layer from an acrylic rubber composition containing at least a carboxyl group-containing acrylic rubber and a polyvalent amine compound, and the acrylic rubber layer An isocyanurate compound and a diazabicycloalkene compound are blended in at least one of the acrylic rubber composition for forming the fluororubber and the fluororubber composition for forming the fluororubber layer, and the acrylic rubber layer and the fluororubber layer It was found that the above-mentioned object can be achieved by crosslinking and bonding, and the present invention has been completed.

  That is, according to the present invention, an acrylic rubber layer (A) comprising an acrylic rubber composition containing at least a carboxyl group-containing acrylic rubber and a polyvalent amine compound, and a fluororubber comprising a fluororubber composition containing at least a fluororubber. A rubber laminate formed by crosslinking and bonding the layer (B), wherein at least one of the acrylic rubber composition and the fluororubber composition contains an isocyanurate compound and a diazabicycloalkene compound. A rubber laminate is provided.

  In the rubber laminate of the present invention, it is preferable that the fluororubber composition further contains an organic peroxide crosslinking agent.

  Moreover, according to this invention, the hose which uses the said rubber laminated body is provided.

  According to the present invention, a rubber laminate formed by crosslinking and bonding an acrylic rubber layer made of an acrylic rubber composition and a fluororubber layer made of a fluororubber composition has improved heat resistance, and A rubber laminate excellent in cross-linking adhesion between the acrylic rubber layer and the fluororubber layer can be provided.

  The rubber laminate of the present invention comprises an acrylic rubber layer (A) comprising an acrylic rubber composition containing at least a carboxyl group-containing acrylic rubber and a polyvalent amine compound, and a fluororubber comprising a fluororubber composition containing at least a fluororubber. Layer (B) is a rubber laminate formed by crosslinking and bonding, and at least one of the acrylic rubber composition and the fluororubber composition contains an isocyanurate compound and a diazabicycloalkene compound. Features.

<Acrylic rubber composition>
First, the acrylic rubber composition for forming the acrylic rubber layer (A) of the rubber laminate of the present invention will be described. The acrylic rubber composition for forming the acrylic rubber layer (A) used in the present invention contains at least a carboxyl group-containing acrylic rubber and a polyvalent amine compound. In the present invention, by using a carboxyl group-containing acrylic rubber as the acrylic rubber for forming the acrylic rubber layer (A), the carboxyl group-containing acrylic rubber is particularly excellent in heat resistance. The heat resistance of the resulting rubber laminate can be improved.

  The carboxyl group-containing acrylic rubber used in the present invention is an acrylic rubber having a carboxyl group, and a (meth) acrylic acid ester monomer [acrylic acid ester monomer and / or methacrylic acid ester as a main component in the molecule. Meaning of monomer. The same applies to methyl (meth) acrylate. It is not particularly limited as long as it contains units and has a carboxyl group. In addition, the carboxyl group contained in the carboxyl group-containing acrylic rubber used in the present invention reacts with the polyvalent amine compound (crosslinking agent) contained in the acrylic rubber composition used in the present invention, whereby the acrylic rubber composition contains In this case, it acts as a crosslinkable group, whereby the heat resistance of the acrylic rubber layer (A) and the rubber laminate containing the acrylic rubber layer (A) can be further improved.

  The carboxyl group-containing acrylic rubber used in the present invention is (a) an acrylic rubber obtained by using an α, β-ethylenically unsaturated carboxylic acid monomer as a monomer used for polymerization, and (b) an acrylic rubber. An acrylic rubber obtained by addition reaction of a carbon-carbon unsaturated bond-containing compound having a carboxyl group in the presence of a radical initiator, or (c) a carboxylic acid ester group, an acid amide group, etc. in the acrylic rubber molecule Any acrylic rubber obtained by converting a part of the carboxylic acid-derived group into a carboxyl group by hydrolysis may be used. In addition, (a) acrylic rubber obtained by using an α, β-ethylenically unsaturated carboxylic acid monomer as a monomer used for polymerization is formed from an α, β-ethylenically unsaturated carboxylic acid monomer. The α, β-ethylenically unsaturated carboxylic acid monomer unit. In the present invention, among these, it is preferable that (a) an acrylic rubber obtained by using an α, β-ethylenically unsaturated carboxylic acid monomer as a monomer used for polymerization, specifically, As the carboxyl group-containing acrylic rubber used in the present invention, (meth) acrylic acid ester monomer unit as a main component is 50 to 99.9% by weight, α, β-ethylenically unsaturated carboxylic acid unit A polymer containing 0.1 to 10% by weight of a monomer unit is preferable.

  Although it does not specifically limit as a (meth) acrylic acid ester monomer which forms the (meth) acrylic acid ester monomer unit which is a main component of the carboxyl group-containing acrylic rubber used by this invention, For example, (meth) acrylic Examples include acid alkyl ester monomers and (meth) acrylic acid alkoxyalkyl ester monomers.

  Although it does not specifically limit as a (meth) acrylic-acid alkylester monomer, The ester of C1-C8 alkanol and (meth) acrylic acid is preferable, Specifically, (meth) acrylic acid methyl, ( (Meth) ethyl acrylate, (meth) acrylic acid n-propyl, (meth) acrylic acid isopropyl, (meth) acrylic acid n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid n-hexyl, (meth) Examples include 2-ethylhexyl acrylate and cyclohexyl (meth) acrylate. Among these, ethyl (meth) acrylate and n-butyl (meth) acrylate are preferable, and ethyl acrylate and n-butyl acrylate are particularly preferable. These can be used individually by 1 type or in combination of 2 or more types.

  Although it does not specifically limit as a (meth) acrylic-acid alkoxyalkylester monomer, The ester of a C2-C8 alkoxyalkyl alcohol and (meth) acrylic acid is preferable, Specifically, (meth) acrylic acid Methoxymethyl, ethoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-propoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate , (Meth) acrylic acid 3-methoxypropyl, (meth) acrylic acid 4-methoxybutyl and the like. Among these, 2-ethoxyethyl (meth) acrylate and 2-methoxyethyl (meth) acrylate are preferable, and 2-ethoxyethyl acrylate and 2-methoxyethyl acrylate are particularly preferable. These can be used individually by 1 type or in combination of 2 or more types.

  The content of the (meth) acrylic acid ester monomer unit in the carboxyl group-containing acrylic rubber used in the present invention is preferably 50 to 99.9% by weight, more preferably 60 to 99.5% by weight, and still more preferably. Is 70 to 99.5% by weight. If the content of the (meth) acrylic acid ester monomer unit is too small, the weather resistance and heat resistance of the acrylic rubber layer (A) may be lowered. On the other hand, if the content is too large, the acrylic rubber layer (A). There is a risk that the heat resistance of the will decrease.

  In the present invention, the (meth) acrylic acid ester monomer unit is a (meth) acrylic acid alkyl ester monomer when the total amount of (meth) acrylic acid ester monomer units is 100% by weight. It is preferable to consist of 30 to 100% by weight of units and 70 to 0% by weight of (meth) acrylic acid alkoxyalkyl ester monomer units.

  Although it does not specifically limit as an alpha, beta-ethylenically unsaturated carboxylic acid monomer, For example, C3-C12 alpha, beta-ethylenically unsaturated monocarboxylic acid, C4-C12 alpha, beta -Ethylenically unsaturated dicarboxylic acid, monoester of C4-C12 alpha, beta-ethylenically unsaturated dicarboxylic acid and C1-C8 alkanol, etc. are mentioned. The α, β-ethylenically unsaturated carboxylic acid monomer acts as a crosslinkable monomer unit in the carboxyl group-containing acrylic rubber.

Specific examples of the α, β-ethylenically unsaturated monocarboxylic acid having 3 to 12 carbon atoms include acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, and cinnamic acid.
Specific examples of the α, β-ethylenically unsaturated dicarboxylic acid having 4 to 12 carbon atoms include butenedionic acid such as fumaric acid and maleic acid; itaconic acid; citraconic acid; chloromaleic acid;
Specific examples of monoesters of α, β-ethylenically unsaturated dicarboxylic acid having 4 to 12 carbon atoms and alkanol having 1 to 8 carbon atoms include monomethyl fumarate, monoethyl fumarate, mono n-butyl fumarate, malein Butenedionic acid mono-chain alkyl esters such as monomethyl acid, monoethyl maleate, mono-n-butyl maleate; monocyclopentyl fumarate, monocyclohexyl fumarate, monocyclohexenyl fumarate, monocyclopentyl maleate, monocyclohexyl maleate, maleic acid Butenedionic acid monoesters having an alicyclic structure such as acid monocyclohexenyl; itaconic acid monoesters such as monomethyl itaconate, monoethyl itaconate, mono n-butyl itaconate, monocyclohexyl itaconate; and the like.
Among these, butenedionic acid mono-chain alkyl ester or butenedionic acid monoester having an alicyclic structure is preferable, and mono n-butyl fumarate, mono n-butyl maleate, monocyclohexyl fumarate, and monocyclohexyl maleate are preferable. More preferred is mono n-butyl fumarate. These α, β-ethylenically unsaturated carboxylic acid monomers can be used alone or in combination of two or more. Among the above monomers, dicarboxylic acids include those that exist as anhydrides.

  The content of the α, β-ethylenically unsaturated carboxylic acid monomer unit in the carboxyl group-containing acrylic rubber used in the present invention is preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight. %, More preferably 0.5 to 5% by weight. If the content of the α, β-ethylenically unsaturated carboxylic acid monomer unit is too large, the elongation of the acrylic rubber layer (A) after crosslinking may be decreased, or the compression set may be increased. On the other hand, if the amount is too small, the mechanical properties of the crosslinked acrylic rubber layer (A) may be insufficient or the heat resistance may be reduced.

The carboxyl group content of the carboxyl group-containing acrylic rubber used in the present invention, that is, the mole number of carboxyl groups per 100 g of acrylic rubber (ephr) is preferably 4 × 10 ⁻⁴ to 4 × 10 ⁻¹ (ephr), More preferably, it is 1 * 10 < ^-3 > -2 * 10 < ^-1 > (ephr), More preferably, it is 5 * 10 < ^-3 > ^-1 * 10 < ^-1 > (ephr). When there is too little content of a carboxyl group, there exists a possibility that the mechanical characteristic of the acrylic rubber layer (A) after bridge | crosslinking may become inadequate, or heat resistance may fall. On the other hand, if the amount is too large, the elongation of the acrylic rubber layer (A) after crosslinking may decrease, or the compression set may increase.

  The carboxyl group-containing acrylic rubber used in the present invention may have other crosslinkable monomer units as needed in addition to the α, β-ethylenically unsaturated carboxylic acid monomer units. The crosslinkable monomer that forms the other crosslinkable monomer unit is not particularly limited. For example, a monomer having a halogen atom; a monomer having an epoxy group; a monomer having a hydroxyl group; Is mentioned.

  These crosslinkable monomers that form the other crosslinkable monomer units may be used alone or in combination of two or more. The content of the other crosslinkable monomer unit in the carboxyl group-containing acrylic rubber used in the present invention can be appropriately determined within a range that does not impair the object and effect of the present invention.

  Moreover, the carboxyl group-containing acrylic rubber used in the present invention has, in addition to the above monomer units, other monomer units that can be copolymerized with the respective monomers as required. Also good.

  Although it does not specifically limit as another monomer which can be copolymerized, For example, it has an aromatic vinyl monomer, an alpha, beta-ethylenically unsaturated nitrile monomer, and two or more (meth) acryloyloxy groups. Examples thereof include monomers (hereinafter sometimes referred to as “polyfunctional (meth) acrylic monomers”), olefinic monomers, and vinyl ether compounds.

Specific examples of the aromatic vinyl monomer include styrene, α-methylstyrene, divinylbenzene, and the like.
Specific examples of the α, β-ethylenically unsaturated nitrile monomer include acrylonitrile and methacrylonitrile.
Specific examples of the polyfunctional (meth) acrylic monomer include ethylene glycol di (meth) acrylate and propylene glycol di (meth) acrylate.
Specific examples of the olefin monomer include ethylene, propylene, 1-butene, and 1-octene.
Specific examples of the vinyl ether compound include vinyl acetate, ethyl vinyl ether, and n-butyl vinyl ether.

  Among these, styrene, acrylonitrile, methacrylonitrile, ethylene and vinyl acetate are preferable, and acrylonitrile, methacrylonitrile and ethylene are more preferable.

Other copolymerizable monomers can be used singly or in combination of two or more. The content of other copolymerizable monomer units in the carboxyl group-containing acrylic rubber used in the present invention is preferably 49.9% by weight or less, more preferably 39.5% by weight or less, and still more preferably 29.5% by weight or less.

  The carboxyl group-containing acrylic rubber used in the present invention can be obtained by polymerizing the above monomers. As the form of the polymerization reaction, any of an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, and a solution polymerization method can be used. From the viewpoint of easy control of the polymerization reaction, a conventionally known acrylic rubber It is preferable to use an emulsion polymerization method under normal pressure, which is generally used as a production method of the above.

  The emulsion polymerization may be any of batch, semi-batch and continuous. The polymerization is usually performed in a temperature range of 0 to 70 ° C, preferably 5 to 50 ° C. After the polymerization, solid carboxyl group-containing acrylic rubber is obtained through solidification and drying.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) (polymer Mooney) of the carboxyl group-containing acrylic rubber used in the present invention thus produced is preferably 10 to 80, more preferably 20 to 70, and even more preferably 25. ~ 60.

  The polyvalent amine compound used in the present invention acts as a crosslinking agent for crosslinking the carboxyl group-containing acrylic rubber described above. The polyvalent amine compound is not particularly limited as long as it is in the form of (1) a compound having two or more amino groups, or (2) a compound having two or more amino groups at the time of crosslinking. And those having a non-conjugated nitrogen-carbon double bond are not included.

  Specific examples of the polyvalent amine compound include aliphatic polyvalent amine compounds such as hexamethylene diamine, hexamethylene diamine carbamate, N, N′-dicinnamylidene-1,6-hexane diamine, or carbonates thereof; 4,4′- Methylene dianiline, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4 '-(m-phenylenediisopropylidene) dianiline, 4,4'- (P-phenylenediisopropylidene) dianiline, 2,2′-bis [4- (4-aminophenoxy) phenyl] propane, 4,4′-diaminobenzanilide, 4,4′-bis (4-aminophenoxy) Biphenyl, m-xylylenediamine, p-xylylenediamine, 1,3, - aromatics such as benzene triamine polyvalent amine compounds; and the like. Among these, an aliphatic polyvalent amine compound or a carbonate thereof is preferable from the viewpoint that the effect of improving the cross-linking adhesion between the acrylic rubber layer (A) and the fluororubber layer (B) is higher, and hexamethylenediamine carbamate is preferable. More preferred. These can be used individually by 1 type or in combination of 2 or more types.

  The content of the polyvalent amine compound in the acrylic rubber composition used in the present invention is preferably 0.05 to 20 parts by weight, preferably 0.1 to 10 parts per 100 parts by weight of the carboxyl group-containing acrylic rubber. Part by weight, more preferably 0.3 to 5 parts by weight. If the content of the polyvalent amine compound is too small, the acrylic rubber may be insufficiently crosslinked. On the other hand, if the amount is too large, the elongation of the acrylic rubber layer (A) after crosslinking may decrease, or the compression set may increase.

  In the present invention, at least one of the acrylic rubber composition for forming the acrylic rubber layer (A) and the fluororubber composition for forming the fluororubber layer (B) includes an isocyanurate compound, and Contains a diazabicycloalkene compound.

  In the present invention, the acrylic rubber layer (A) in the rubber laminate obtained by containing an isocyanurate compound and a diazabicycloalkene compound in at least one of the acrylic rubber composition and the fluororubber composition, Cross-linking adhesiveness with the fluororubber layer (B) can be improved. In particular, the present inventors have studied a rubber used in combination with a fluororubber in order to improve the heat resistance of the rubber laminate, and the heat resistance of the rubber laminate obtained by using a carboxyl group-containing acrylic rubber. Found to improve. However, on the other hand, the carboxyl group-containing acrylic rubber does not necessarily have sufficient cross-linking adhesiveness to fluororubber. On the other hand, when the improvement of cross-linking adhesiveness was studied, isocyanurate compound and diazabicycloalkene compound In combination, and by blending them in at least one of the acrylic rubber layer (A) and the fluororubber layer (B), the acrylic rubber layer (A) and the fluororubber layer (B It has been found that the cross-linking adhesiveness to the above can be improved. Thus, according to the present invention, it is possible to provide a rubber laminate excellent in heat resistance and excellent in cross-linking adhesion between the acrylic rubber layer (A) and the fluororubber layer (B). is there.

  In the following, the acrylic rubber composition for forming the acrylic rubber layer (A) will be described by exemplifying a case where an isocyanurate compound and a diazabicycloalkene compound are contained. When it is contained in the fluororubber composition for forming B), the acrylic rubber composition does not necessarily need to contain these isocyanurate compounds and diazabicycloalkene compounds.

  The isocyanurate compound is a compound formed by substituting the H portion of the —NH— group of isocyanuric acid, and is not particularly limited. For example, 1-allyl isocyanurate, 1,3-diallyl isocyanurate, 1,3-diallyl -5-benzylallyl isocyanurate, triallyl isocyanurate, 1-allyl-3,5-dibenzyl isocyanurate, 1-allyl-3,5-diglycidyl isocyanurate, 1,3-diallyl-5-glycidyl isocyanurate, And triglycidyl isocyanurate. These can be used individually by 1 type or in combination of 2 or more types. Among these, triallyl isocyanurate is preferable from the viewpoint that the effect of addition is higher.

  When the isocyanurate compound is contained in the acrylic rubber composition used in the present invention, the content of the isocyanurate compound is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the carboxyl group-containing acrylic rubber. Yes, more preferably 0.1 to 10 parts by weight, still more preferably 0.5 to 10 parts by weight. If the content of the isocyanurate compound is too low, it is difficult to obtain the effect of blending the isocyanurate compound, that is, the effect of improving the cross-linking adhesion between the acrylic rubber layer (A) and the fluororubber layer (B). If the content is too high, the elongation of the acrylic rubber layer (A) after crosslinking may decrease.

  The diazabicycloalkene compound is not particularly limited as long as it is an alkene compound having a diazabicyclo structure. For example, 1,8-diazabicyclo [5.4.0] undec-7-ene (also referred to as “DBU”), 1 , 4-diazabicyclo [2.2.2] octane (also referred to as “DABCO”), 1,5-diazabicyclo [4.3.0] non-5-ene (also referred to as “DPN”), and the like. These diazabicycloalkene compounds may form a salt, and examples of the compound that forms the salt include hydrochloric acid, sulfuric acid, carboxylic acid, sulfonic acid, phenol and the like. Examples of the carboxylic acid include octylic acid, oleic acid, formic acid, orthophthalic acid, adipic acid and the like. Examples of the sulfonic acid include benzenesulfonic acid, toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid and the like. These can be used individually by 1 type or in combination of 2 or more types. Among these, 1,8-diazabicyclo [5.4.0] undec-7-ene or a salt thereof is preferable from the viewpoint that the addition effect is higher, and 1,8-diazabicyclo [5.4.0]. More preferred is the phenol salt of undec-7-ene.

  When the diazabicycloalkene compound is contained in the acrylic rubber composition used in the present invention, the content ratio of the diazabicycloalkene compound is preferably 0.01 to 100 parts by weight of the carboxyl group-containing acrylic rubber. 20 parts by weight, more preferably 0.1 to 10 parts by weight, still more preferably 0.1 to 5 parts by weight. When the content ratio of the diazabicycloalkene compound is too low, the effect of blending the diazabicycloalkene compound, that is, the effect of improving the cross-linking adhesion between the acrylic rubber layer (A) and the fluororubber layer (B) is obtained. On the other hand, if the content is too high, the elongation of the crosslinked acrylic rubber layer (A) may be reduced.

  Moreover, in the acrylic rubber composition used in the present invention, in addition to the above components, a compounding agent usually used in the rubber processing field can be blended. Examples of such compounding agents include reinforcing fillers such as carbon black and silica; non-reinforcing fillers such as calcium carbonate and clay; cross-linking accelerators; anti-aging agents; light stabilizers; plasticizers; Agents; lubricants; pressure-sensitive adhesives; lubricants; flame retardants; antifungal agents; antistatic agents; coloring agents; silane coupling agents; The compounding amount of these compounding agents is not particularly limited as long as it does not impair the object and effect of the present invention, and an amount corresponding to the compounding purpose can be appropriately compounded.

  The method for preparing the acrylic rubber composition used in the present invention is not particularly limited, and each component may be kneaded according to a conventional method. For example, a component excluding a thermally unstable component such as a polyvalent amine compound as a crosslinking agent may be used. After kneading the carboxyl group-containing acrylic rubber, a heat-unstable component such as a polyvalent amine compound can be mixed in the kneaded material in a short time to obtain the desired composition.

<Fluorine rubber composition>
Next, the fluororubber composition for forming the fluororubber layer (B) of the rubber laminate of the present invention will be described. The fluororubber composition used in the present invention contains at least fluororubber.

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

  In the present invention, as the fluororubber, binary copolymer rubber such as vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-perfluoromethyl vinyl ether copolymer, And a terpolymer rubber of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, and a rubber obtained by copolymerizing such a terpolymer rubber with a crosslinkable monomer. Among these, a terpolymer rubber and a rubber obtained by copolymerizing a crosslinkable monomer are particularly preferable from the viewpoint of particularly excellent gasohol resistance.

Further, as described above, in the present invention, at least one of the acrylic rubber composition for forming the acrylic rubber layer (A) and the fluororubber composition for forming the fluororubber layer (B) It contains a nurate compound and a diazabicycloalkene compound.
Hereinafter, the acrylic rubber composition described above will be described by exemplifying the case where the fluororubber composition for forming the fluororubber layer (B) contains an isocyanurate compound and a diazabicycloalkene compound. Similarly, when these are contained in the acrylic rubber composition for forming the acrylic rubber layer (A), the fluororubber composition does not necessarily contain these isocyanurate compounds and diazabicycloalkene compounds. You don't have to.

  As the isocyanurate compound, the compounds exemplified in the description of the acrylic rubber composition can be used. When the isocyanurate compound is contained in the fluororubber composition, the content of the isocyanurate compound is 100 parts by weight of the fluororubber. The amount is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and still more preferably 0.5 to 10 parts by weight. If the content of the isocyanurate compound is too low, it is difficult to obtain the effect of blending the isocyanurate compound, that is, the effect of improving the cross-linking adhesion between the acrylic rubber layer (A) and the fluororubber layer (B). If the content is too high, the elongation of the fluororubber layer (B) after crosslinking may decrease.

  In addition, as the diazabicycloalkene compound, the compounds exemplified in the description of the acrylic rubber composition can be used. When the diazabicycloalkene compound is contained in the fluororubber composition, the diazabicycloalkene compound is contained. The ratio is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and still more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the fluororubber. When the content ratio of the diazabicycloalkene compound is too low, the effect of blending the diazabicycloalkene compound, that is, the effect of improving the cross-linking adhesion between the acrylic rubber layer (A) and the fluororubber layer (B) is obtained. On the other hand, if the content ratio is too high, the elongation of the fluororubber layer (B) after crosslinking may decrease.

  Moreover, it is preferable that the fluororubber composition used by this invention contains the crosslinking agent for bridge | crosslinking fluororubber in addition to said each component. The crosslinking agent is not particularly limited, and conventionally known crosslinking agents such as a polyol-based crosslinking agent, an organic peroxide-based crosslinking agent, and an amine-based crosslinking agent can be used for crosslinking the fluororubber. . In particular, the fluororubber composition used in the present invention has an organic peroxide cross-linking as a cross-linking agent from the viewpoint that the effect of improving the cross-linking adhesion between the acrylic rubber layer (A) and the fluoro rubber layer (B) is higher. More preferably, it further contains an agent. Although it does not specifically limit as an organic peroxide type crosslinking agent, For example, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) -3 -Dialkyl peroxides such as hexyne, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 1,3-bis (t-butylperoxyisopropyl) benzene; benzoyl peroxide, isobutyryl per And diacyl peroxides such as oxide; and peroxy esters such as 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane and t-butylperoxyisopropyl carbonate; Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is preferable. These can be used individually by 1 type or in combination of 2 or more types.

  The content ratio of the organic peroxide crosslinking agent in the fluororubber composition used in the present invention is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 100 parts by weight of the fluororubber. -5 parts by weight, more preferably 0.1-5 parts by weight. When the content ratio of the organic peroxide crosslinking agent is too low, the crosslinking of the fluororubber may be insufficient. On the other hand, if the content is too high, the elongation of the fluororubber layer (B) after crosslinking may be reduced.

  In addition to the above components, the fluororubber composition used in the present invention may contain a compounding agent usually used in the rubber processing field. Examples of such compounding agents include reinforcing fillers such as carbon black and silica; acid acceptors such as magnesium oxide; cross-linking accelerators; anti-aging agents; light stabilizers; plasticizers; processing aids; Adhesives; lubricants; flame retardants; antifungal agents; antistatic agents; coloring agents; silane coupling agents; The compounding amount of these compounding agents is not particularly limited as long as it does not impair the object and effect of the present invention, and an amount corresponding to the compounding purpose can be appropriately compounded.

  The method for preparing the fluororubber composition used in the present invention is not particularly limited, and each component may be kneaded according to a conventional method. For example, the target composition can be obtained by kneading fluororubber and each compounding agent. it can.

<Rubber laminate>
Next, the rubber laminate of the present invention will be described. The rubber laminate of the present invention is a rubber laminate obtained by crosslinking and bonding the acrylic rubber layer (A) made of the above-described acrylic rubber composition and the fluororubber layer (B) made of the fluororubber composition.

  Although the manufacturing method of the rubber laminated body of this invention is not limited, For example, it can manufacture by the following method. That is, first, the acrylic rubber composition and the fluororubber composition described above are separately separated from each other by a known method such as press molding, roll molding, extrusion molding, and the thickness is preferably 0.1 to 5 mm, more preferably 0. It is molded into a sheet having an arbitrary area of 5 to 3 mm (acrylic rubber layer (A) sheet, fluorine rubber layer (B) sheet) in an uncrosslinked state. Next, the rubber laminate of the present invention can be obtained by bringing the obtained sheets into contact with each other, followed by pressure-heat crosslinking using a hot press or a vulcanizing can and bonding them. Alternatively, a method in which the acrylic rubber composition and the fluororubber composition are molded into a laminated tube in an uncrosslinked state by a layer extrusion method, and then subjected to pressure-heat crosslinking using a vulcanizing can and bonded. Also good. Hot pressing is usually performed at a temperature of 140 to 200 ° C. and a pressure of 0.2 to 15 MPa for 5 to 60 minutes. Moreover, when using a vulcanizing can, it is normally performed for 30 to 120 minutes under the pressure of 0.18 MPa at the temperature of 130-160 degreeC.

  Further, by further heat-treating (post-cure) the obtained rubber laminate, it is possible to shorten the crosslinking time for crosslinking (primary crosslinking) and to improve the compression set of the rubber laminate.

  The rubber laminate of the present invention is not limited to the form in which the acrylic rubber layer (A) and the fluororubber layer (B) are laminated one by one, as long as they have portions laminated alternately. One or both of these may be formed in a plurality of layers. Further, the rubber laminate of the present invention may have other layers made of other materials, and such other materials are suitable depending on required characteristics, intended use, etc. For example, epichlorohydrin rubber, acrylonitrile-butadiene rubber, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, chlorosulfonated polyethylene rubber, and the like can be used.

  The rubber laminate of the present invention obtained in this way is formed by using a carboxyl group-containing acrylic rubber, which is a rubber having excellent heat resistance, as the acrylic rubber constituting the acrylic rubber layer (A). It has excellent heat resistance and excellent cross-linking adhesiveness between the acrylic rubber layer (A) and the fluororubber layer (B) constituting the rubber laminate. Therefore, the rubber laminate of the present invention takes advantage of these characteristics, for example, O-rings, gaskets, packings, oil seals, bearing seals and the like in a wide range of transportation machines such as automobiles, general equipment, and electrical equipment. Sealing materials; oil tubes, fuel hoses, air hoses, turbo air hoses, PCV hoses, inlet hoses, and other hoses; transmission belts, endless belts, and other industrial belts; Useful as sheets; boots; dust covers; Especially, the rubber laminated body of this invention can be used especially suitably for a hose use.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples. In the following, “part” and “%” are based on weight unless otherwise specified. Moreover, the test and evaluation followed the following.

[Peel test]
Using the obtained rubber laminate, a peel test was performed according to JIS K6256 to evaluate the cross-linking adhesiveness between both layers constituting the rubber laminate. Specifically, the obtained rubber laminate was punched into a strip shape 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 at a speed of 50 mm / min, 180 °. A peel test was performed, the load at the time of peeling was read with a load cell of a tensile tester, and the peel strength T _F (N / mm) was obtained.
In addition to the measurement of the peel strength, the state of the adhesive interface after the peel test was visually confirmed to evaluate the peel state. The condition of the adhesive interface is to check whether one rubber layer remains on the other rubber layer on the peeled surface after the peel test, and one rubber layer remains on the other rubber layer. (Ie, one rubber layer is completely destroyed), it is determined as “rubber destruction”, and one rubber layer is not left on the other rubber layer (ie, each rubber layer is broken). In the case where the rubber layer was peeled along the interface without being broken, it was determined as “interface peeling”.
As the value of the peel strength _TF is larger, and when the state of the adhesive interface is “rubber breakage”, it means that the rubber laminate is excellent in cross-linking adhesion.

[Production Example 1]
[Production of carboxyl group-containing acrylic rubber]
A polymerization reactor equipped with a thermometer and a stirrer was charged with 200 parts of water, 3 parts of sodium lauryl sulfate, 58 parts of ethyl acrylate, 40 parts of n-butyl acrylate, and 2 parts of mono n-butyl fumarate. Then, after depressurization and nitrogen substitution twice to sufficiently remove oxygen, 0.005 part of cumene hydroperoxide and 0.002 part of sodium formaldehydesulfoxylate were added and emulsified at a temperature of 30 ° C. under normal pressure. Polymerization was started and the reaction was continued until the polymerization conversion reached 95%. And the obtained emulsion polymerization liquid was coagulated with calcium chloride aqueous solution, washed with water and dried to obtain carboxyl group-containing acrylic rubber (A-1). The resulting carboxyl group-containing acrylic rubber (A-1) has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 45, and as a result of ¹ H-NMR measurement, the composition is 58% ethyl acrylate monomer units, It was 40% of n-butyl acrylate monomer unit and 2% of mono n-butyl fumarate monomer unit.

[Example 1]
[Preparation of acrylic rubber composition]
Using a Banbury mixer, 100 parts of the carboxyl group-containing acrylic rubber (A-1) obtained in Production Example 1, 50 parts of carbon black (trade name “Seast SO”, manufactured by Tokai Carbon Co., Ltd., filler), stearic acid 1 part, ester wax (trade name “Greg G-8205”, manufactured by Dainippon Ink & Chemicals, lubricant), 1 part, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine (trade name “NOCRACK CD” 2 parts of an anti-aging agent manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) was added and kneaded at 50 ° C. for 5 minutes. Subsequently, the obtained kneaded material was transferred to an open roll at 50 ° C., and 0.5 parts of hexamethylenediamine carbamate (trade name “Diak No. 1”, manufactured by DuPont Dow Elastomer Japan Co., Ltd.), 1,3- 2 parts of di-o-tolylguanidine (trade name “Noxeller DT”, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., crosslinking accelerator), phenol salt of 1,8-diazabicyclo [5.4.0] undec-7-ene ( By adding 0.5 part of the trade name “U-CAT SA1” (manufactured by San Apro) and 1 part of triallyl isocyanurate (trade name “TAIC”, manufactured by Nippon Kasei Co., Ltd.) and kneading at 50 ° C. An acrylic rubber composition was obtained.

[Preparation of fluororubber composition]
Using an open roll, 100 parts of fluororubber (trade name “VITON GBL200S”, manufactured by DuPont, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer rubber copolymerized with olefin bromide) In addition, MT carbon black (trade name “Thermax MT”, manufactured by cancarb, a filler) 30 parts, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane 40% purity product (product) Add the name “Perhexa 25B-40”, 2 parts by Nippon Oil & Fats Chemical Co., Ltd., organic peroxide cross-linking agent, and 3 parts triallyl isocyanurate (trade name “TAIC”, produced by Nippon Kasei Co., Ltd.) at 50 ° C. The fluororubber composition was obtained by kneading.

[Manufacture of rubber laminate]
Then, the acrylic rubber composition and the fluororubber composition obtained above are each kneaded with an open roll, dispensed into a sheet having a uniform thickness of about 2 mm, and molded into a 6 cm × 10 cm square. A sheet-like molded body was obtained. Next, the obtained sheet-like molded bodies are bonded together, put into a mold having a length of 6 cm, a width of 10 cm, and a depth of 0.4 cm, and subjected to cross-linking adhesion at 170 ° C. for 20 minutes while pressing at a press pressure of 50 kg / cm ² . Thus, a rubber laminate was produced. At this time, in order to perform the above-described peel test, the cellophane paper was previously sandwiched between the portions gripped by the air chuck during the peel test, thereby forming a portion where both sheets were not adhered.

  And the peeling test was done using the rubber laminated body obtained in this way. The results are shown in Table 1.

[Comparative Example 1]
In preparing the acrylic rubber composition, 0.5 parts of 1,8-diazabicyclo [5.4.0] undec-7-ene phenol salt and 1 part of triallyl isocyanurate were not blended. An acrylic rubber composition was produced in the same manner as in Example 1, and a rubber laminate was obtained in the same manner as in Example 1 and was similarly tested and evaluated. The results are shown in Table 1.

  From Table 1, an acrylic rubber composition comprising a carboxyl group-containing acrylic rubber and a polyamine compound, 1,8-diazabicyclo [5.4.0] undec-7-ene phenol salt, and triallyl isocyanurate. The rubber laminate obtained by crosslinking and bonding the acrylic rubber layer (A) comprising the acrylic rubber composition and the fluororubber layer (B) has a high peel strength, This situation was also “rubber failure” and was excellent in cross-linking adhesion between both layers. Moreover, since the carboxyl group-containing acrylic rubber excellent in heat resistance is used as the acrylic rubber forming the acrylic rubber layer (A), it also has excellent heat resistance (Example 1).

  On the other hand, as an acrylic rubber composition for forming the acrylic rubber layer (A), a composition containing no phenol salt of 1,8-diazabicyclo [5.4.0] undec-7-ene and triallyl isocyanurate When used, the resulting rubber laminate has a low peel strength, and the adhesive interface is also “interfacial peel”, resulting in poor cross-linking adhesion between the two layers (Comparative Example 1). .

Claims (3)

An acrylic rubber layer (A) comprising an acrylic rubber composition containing at least a carboxyl group-containing acrylic rubber and a polyvalent amine compound and a fluororubber layer (B) comprising a fluororubber composition containing at least a fluororubber are crosslinked. It is a rubber laminate formed by bonding,
At least one of the acrylic rubber composition and the fluororubber composition contains an isocyanurate compound and a diazabicycloalkene compound.   The rubber laminate according to claim 1, wherein the fluororubber composition further contains an organic peroxide crosslinking agent.   A hose comprising the rubber laminate according to claim 1.