WO2007026596A1 - Rubber composition and cross-linked product - Google Patents

Abstract

A rubber composition comprising an acrylic rubber having at least one group selected from a carboxyl group and an epoxy group, a compound having a ketimine structure, carbon black and a cross-linking agent. Preferably, the acrylic rubber has a group selected from a carboxyl group and an epoxy group in an amount of 4 × 10-4 to 4 × 10-1 equivalent per 100 g of the rubber, and the composition contains 100 parts by weight of the acrylic rubber, 0.01 to 10 parts by weight of the compound having a ketimine structure, 20 to 200 parts by weight of carbon black, and 0.05 to 20 parts by weight of the cross-linking agent (preferably a polyvalent amine cross-linking agent). Preferably, the composition further comprises a silane coupling agent. The rubber composition is excellent in scorch stability, and shows a high cross-linking rate. A product produced by cross-linking the composition has a high tensile strength and a low permanent compression set.

Description

 Specification

 Rubber composition and cross-linked product

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a rubber composition and a crosslinked product thereof, and more specifically, a rubber composition having excellent scorch stability and high crosslinking speed, and a tensile composition obtained by crosslinking the rubber composition. The present invention relates to a crosslinked product having high strength and low compression set.

 Background art

 [0002] Acrylic rubber (for example, ethyl acrylate-normal butyl acrylate copolymer) is excellent in heat resistance and oil resistance, and is used in rubber parts in a wide range of fields including automobiles. . Recently, with seal materials, hose materials, anti-vibration materials, tube materials, belt materials and boot materials! For each member! On the other hand, there is a strong demand for acrylic rubbers that are further superior in tensile strength and compression set resistance.

 [0003] Patent Document 1 proposes an acrylic rubber composition containing a chlorine group-containing acrylic rubber, a silane coupling agent, carbon black, and a quaternary ammonium salt. However, this composition has a problem of lack of scorch stability in the process from molding to crosslinking. In addition, since a crosslinked product obtained by crosslinking this composition contains chlorine groups, it has a problem if it generates wrinkles when used in contact with a metal material.

 [0004] In Patent Document 2, an acrylic elastomer containing a specific amount of a mono-lower alkyl ester monomer of fumaric acid, an aromatic diamine compound vulcanizing agent, and a guanidine compound vulcanizing agent. An elastomer composition is disclosed. However, this composition has a problem in that the molding cycleability (productivity) is inferior because the vulcanization speed is low.

 Patent Document 1: Japanese Patent Application Laid-Open No. 2002-179874

 Patent Document 2: JP-A-11-92614

 Disclosure of the invention

 Problems to be solved by the invention

[0006] The present invention has been made in view of such a situation, and an object thereof is excellent in scorch stability, high crosslinking speed, high tensile strength, and low compression set. It is to provide a rubber composition that can give a cross-linked product.

 Means for solving the problem

 [0007] As a result of intensive studies to achieve the above object, the present inventors have found that a carboxyl group and

It has been found that the above object can be achieved by a crosslinkable rubber composition obtained by blending carbon black as a reinforcing agent, a ketimine structure-containing compound, and a crosslinking agent with Z or an epoxy group-containing acrylic rubber. The present invention has been completed based on the findings.

 That is, according to the present invention, an acrylic rubber, a ketimine structure-containing compound, a carbon black, and a rubber containing a cross-linking agent containing at least one kind of group having a selected carboxyl group and epoxy group. A composition is provided.

[0009] Preferably, the rubber composition of the present invention, acrylic rubber 100 a group forces also Barre selected among carboxyl group and an epoxy group, per the rubber LOOG, containing ⁴ X 10- 4 ~4 X 10- ¹ eq The ketimine structure-containing compound is contained in an amount of 0.01 to: L0 parts by weight, carbon black 20 to 200 parts by weight, and a crosslinking agent, preferably a polyvalent amine crosslinking agent 0.05 to 20 parts by weight. Preferably, it further contains a silane coupling agent.

 The crosslinked product of the present invention is obtained by crosslinking the above rubber composition. The invention's effect

 [0010] The rubber composition of the present invention is excellent in scorch stability and has a high crosslinking rate. Further, by crosslinking this rubber composition, a bridge structure having a high tensile strength and a small compression set can be obtained. Therefore, the rubber composition of the present invention can be suitably used as a sealing material, a hose material, a vibration isolating material, a tube material, a belt material, a boot material and the like by making full use of these characteristics.

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0011] The acrylic rubber, the ketimine structure-containing compound, the carbon black and the cross-linking agent containing at least one group selected from the carboxyl group and the epoxy group, which are components constituting the rubber composition of the present invention, are described below. I will explain in order.

[0012] An acrylic rubber containing at least one kind of group selected from the carboxyl group and epoxy group used in the present invention (hereinafter sometimes referred to as "carboxyl group- or epoxy group-containing acrylic rubber") (Meth) acrylic acid ester monomer [“acrylic acid ester Meaning "mer or z and methacrylate monomer". Hereinafter, (meth) acrylic acid methyl and the like are also used in the same meaning. ] A polymer having a unit as a main component and containing a carboxyl group as a crosslinking point and z or an epoxy group.

 [0013] The carboxyl group- or epoxy-group-containing acrylic rubber used in the present invention contains (meth) acrylic acid ester monomer units in the molecule, preferably 70% by weight or more, more preferably 80% by weight or more. .

 [0014] Examples of the (meth) acrylic acid ester monomer that is the main raw material of the monomer unit constituting the carboxyl group-containing acrylic rubber include (meth) acrylic acid alkyl ester monomers, (meth) Examples include acrylic acid alkoxyalkyl ester monomers.

 [0015] The (meth) acrylic acid alkyl ester monomer is preferably an ester of an alkenol having 1 to 8 carbon atoms and (meth) acrylic acid. Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid. Examples include isobutyl, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate. Of these, ethyl (meth) acrylate and n-butyl (meth) acrylate are preferred.

 [0016] The (meth) acrylic acid alkoxyalkyl ester monomer is preferably an ester of an alcohol having 2 to 8 carbon atoms and (meth) acrylic acid! /. Specific examples thereof include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-butoxetyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, (Meth) acrylic acid 2-propoxycetyl, (meth) acrylic acid 3-methoxypropyl, (meth) acrylic acid 4-methoxybutyl and the like. Of these, 2-ethoxyethyl (meth) acrylate and 2-methoxyethyl (meth) acrylate are preferred, and 2-ethoxyethyl acrylate and 2-methoxyethyl acrylate are particularly preferred.

[0017] The carboxyl group- or epoxy-group-containing acrylic rubber used in the present invention is a polymer in which cross-linking is formed substantially using a force-loxyl group and z or an epoxy group as a cross-linking point. This polymer has a glass transition temperature of preferably 20 ° C or lower, more preferably 10 ° C or lower, and particularly preferably 0 ° C or lower. This cross-linked product of carboxyl group or epoxy group-containing acrylic rubber has characteristics that are excellent in metal corrosion resistance and contamination as compared with a cross-linked product of a chlorine group having a cross-linking point.

[0018] The total content of carboxyl group and Epoki sheet group of a carboxyl group or an epoxy group-containing acrylic rubber, per rubber LOOG, preferably ⁴ X 10- 4 ~4 X 10- ¹ equivalents, more preferred properly is 1 X 10 - ³ ~2 X 10- ¹ equivalent, particularly preferably 5 X 10- ³ ~1 X 10- ¹ eq. When the carboxyl group and Z or epoxy group content is within the above range, a crosslinked product having sufficient mechanical strength and elongation can be obtained by crosslinking.

 [0019] To prepare an acrylic rubber containing at least one group selected from a carboxyl group and an epoxy group, (i) a carboxyl group-containing monomer unit at the time of polymerization for preparing the acrylic rubber And a method of copolymerizing at least one kind of monomer selected from among epoxy group-containing monomer units, (mouth) for acrylic rubber having neither carboxyl group nor epoxy group A method of grafting at least one compound selected from a carbon-carbon unsaturated bond-containing compound having a carboxyl group and a carbon-carbon unsaturated bond-containing compound having an epoxy group in the presence of a radical initiator (C) Hydrolysis of some of the carboxylic acid derivative groups of acrylic rubber having carboxylic acid derivative groups such as carboxylic acid ester groups and acid amide groups by hydrolysis. The method of converting to, etc. is taken. What is necessary is just to select the method suitable for the target acrylic rubber crosslinked material.

 [0020] Preferably, the method for producing a carboxyl group- and Z- or epoxy-group-containing acrylic rubber comprises the method (i), ie, a monomer containing a (meth) acrylate monomer, a carboxyl group and Z or an epoxy group. This is a method of copolymerizing a monomer and other copolymerizable monomers that can be prepared as required.

[0021] In the method (i), the (meth) acrylic acid ester monomer used as the main raw material is, as described above, (meth) acrylic acid alkyl ester monomer, (meth) acrylic acid alkylalkyl. An ester monomer or the like is used. Among them, as the alkyl ester monomer (meth) acrylate, ethyl (meth) acrylate and n-butyl (meth) acrylate are preferable. (Meth) acrylic acid alkoxyalkyl ester monomers are preferably (meth) acrylic acid 2-ethoxyethyl and (meth) acrylic acid 2-methoxyethyl, especially 2-acrylic acid acrylic acid and 2-methoxyethyl acrylic acid. Is preferred! These monomers can be used alone or in combination of two or more.

[0022] The carboxyl group-containing monomer used in the production of the carboxyl group-containing acrylic rubber by the method (i) is a carboxyl group-containing monomer copolymerizable with a (meth) acrylic acid ester monomer. If so, there is no particular limitation. Examples of such carboxyl group-containing monomers include α, β ethylenically unsaturated monocarboxylic acids having 3 to 12 carbon atoms, a 4 to 12 carbon atoms, β ethylenically unsaturated dicarboxylic acids, and 4 carbon atoms. To: monoesters of L 1 o, β-ethylene unsaturated dicarboxylic acid and C 1-8 alkanol.

 [0023] Examples of the α, β-ethylenically unsaturated monocarboxylic acid having 3 to 12 carbon atoms include acrylic acid, methacrylic acid, ethylacrylic acid, crotonic acid, and cinnamic acid.

 Examples of the α, β unsaturated dicarboxylic acid having 4 to 12 carbon atoms include butenedionic acid such as fumaric acid and maleic acid, itaconic acid and citraconic acid.

 [0024] Carbon number 4 to: Specific examples of monoesters of a 1, j8-unsaturated dicarboxylic acid of L 1 and alunol having 1 to 8 carbon atoms include monomethyl fumarate, monoethyl fumarate, and monofumarate. Non-butyl, monomethyl maleate, monoethyl maleate, mono-n-butyl maleate butenedionic acid mono-chain alkyl esters; monocyclopentyl fumarate, monocyclohexyl fumarate, monocyclohexyl fumarate, Butenedionic acid monoesters having an alicyclic structure such as monocyclopentyl maleate, monocyclohexyl maleate, monocyclohexyl maleate; itaconic acid monoesters such as monomethyl itaconate, monoethyl itaconate, monobutyl itaconate; fumarate Butenedionate hydroxy, such as acid mono 2-hydroxyethyl Monoesters; and the like.

 [0025] Of these, butenedionic acid mono-chain alkyl esters and butenedionic acid monoesters having an alicyclic structure are preferred, particularly mono n-butyl fumarate, mono n-butyl maleate, and monocyclo fumarate. Xylyl and monocyclohexyl maleate are preferred. These can be used alone or in combination of two or more.

[0026] The content of the carboxyl group-containing monomer unit is preferably 0.5 to 20% by weight, more preferably 0.7 to 15% by weight based on 100% by weight of the total monomer units. % It is preferably 1 to 12% by weight. If there are too few carboxyl group-containing monomer units, the cross-linked density of the cross-linked product may be insufficient, and good mechanical properties may not be obtained, and the surface skin of the molded product may lack slippery force. On the other hand, when there are too many carboxyl group-containing monomer units, there is a possibility that the elongation of the cross-linked product is lowered or the hardness becomes too high.

 [0027] Among the above monomers, when copolymerization is performed using a dicarboxylic acid, an anhydrous product thereof may be used. In this case, it is hydrolyzed before crosslinking to generate carboxyl groups to form crosslinking points.

 [0028] The epoxy group-containing monomer used in the production of the epoxy group-containing acrylic rubber by the method (i) above may be an epoxy group-containing monomer copolymerizable with a (meth) acrylic acid ester monomer. If it does not specifically limit. Examples of such an epoxy group-containing monomer include an epoxy group-containing unsaturated hydrocarbon compound, a glycidyl ester group-containing unsaturated hydrocarbon compound, and a glycidyl ether group-containing unsaturated hydrocarbon compound.

 [0029] Examples of the epoxy group-containing unsaturated hydrocarbon compound include 3, 4 epoxy 1-butene, 1, 2 epoxy-3 pentene, 1, 2 epoxy 5, 9 cyclododecadiene, and the like.

 Examples of the unsaturated hydrocarbon compound containing a glycidyl ester group include glycidyl (meth) atalylate, glycidyl crotonate, glycidyl 4-heptenoate, glycidyl sorbate, glycidyl linoleate, glycidyl ester of 3-cyclohexene carboxylic acid, Examples include 4-methyl-3-cyclohexenecarboxylic acid glycidyl ester, glycidyl 4-methyl-3-pentenoate, and the like.

[0030] Examples of the glycidyl ether group-containing unsaturated hydrocarbon compound include burglycidyl ether, allyl glycidyl ether, o-aryl glycidyl ether, and the like.

 Of these, glycidyl ether group-containing unsaturated hydrocarbon compounds are preferred, especially allyl glycidyl ether! /.

[0031] In addition, the carboxyl group- or epoxy-group-containing acrylic rubber contains, for example, a hydroxyl group-containing monomer unit having a carboxyl group and a crosslinkable group other than Z or an epoxy group. A monomer having a crosslinkable group such as a monomer; a monomer having a conjugated or non-conjugated monomer; and the like.

 [0032] The hydroxyl group-containing monomer is not particularly limited, and examples thereof include a hydroxyl group-containing (meth) acrylate compound, a hydroxyl group-containing (meth) acrylamide compound, and a vinyl alcohol compound.

 Specific examples of hydroxyl-containing (meth) acrylic acid ester compounds include (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2 hydroxypropyl, (meth) acrylic acid 3 hydroxypropyl, (meth) Examples include 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.

 Examples of the hydroxyl group-containing (meth) acrylamide compound include N-hydroxy (meth) acrylamide.

 [0033] Examples of the conjugation monomer include 1,3 butadiene, 1,3 pentagen, isoprene, 2,3 dimethyl-1,3 butadiene, 1,3 pentagen, and the like, among which 1,3-butadiene is preferable. .

 Examples of the non-conjugated diene monomer include 5-ethylidene-2-norbornene and dicyclopentadiene.

 [0034] These monomers having a crosslinkable group other than a carboxyl group or an epoxy group can be used singly or in combination of two or more.

 The content of the monomer unit having a crosslinkable group other than the carboxyl group and Z or epoxy group in the acrylic rubber is preferably 0 with respect to 100% by weight of the total monomer units.

-5% by weight, more preferably 0-3% by weight.

[0035] In addition to the above, the carboxyl group- or epoxy-group-containing acrylic rubber is a unit of a monomer that can be copolymerized with each of the above-described monomers, if necessary, as long as the object of the present invention is not impaired. Containing, may be.

 Examples of such copolymerizable monomers include aromatic vinyl monomers, α, β-ethylenically unsaturated-tolyl monomers, and monomers having two or more attaryloxy groups (multifunctional Acryl monomer) and other olefin monomers.

[0036] Examples of the aromatic bur monomer include styrene, a-methyl styrene, and dibulene benzene. And so on.

 Examples of the a, β-ethylenically unsaturated-tolyl monomer include acrylonitrile and meta-tallow-tolyl.

 Examples of the polyfunctional acrylic monomer include (meth) acrylic acid diester of ethylene glycol and (meth) acrylic acid diester of propylene glycol.

 Other olefin-based monomers include ethylene, propylene, butyl acetate, ethyl butyl ether, butyl butyl ether, and the like.

 Among these copolymerizable monomers, acrylonitrile and methallyl-tolyl are preferred.

[0037] The content of such copolymerizable monomer units is preferably ^{0 to} 49.9 weights 0/0, more preferably _{0 to} 20 weights, based on 100 weight percent of all monomer units. _^0/0.

 [0038] For the production of carboxyl group- or epoxy-group-containing acrylic rubber, (meth) acrylate monomer, carboxyl group- or epoxy-group-containing monomer, other than carboxyl group or epoxy group used as necessary As a polymerization method for copolymerizing a monomer mixture such as a monomer having a cross-linking point and a monomer copolymerizable therewith, a known emulsion polymerization method, suspension polymerization method, bulk polymerization method and solution can be used. Any of the polymerization methods can be used. Among these, the emulsion polymerization method under normal pressure is preferable because of easy control of the polymerization reaction.

 [0039] In the production of the carboxyl group-containing acrylic rubber by the above (mouth) method, as the carbon-carbon unsaturated bond-containing compound having a carboxyl group for graft-modifying acrylic rubber, the above-mentioned a , j8—ethylenically unsaturated monocarboxylic acid, α, β—ethylenically unsaturated dicarboxylic acid and its anhydride, a, j8—ethylenically unsaturated dicarboxylic acid monoesterol, etc.

[0040] In the production of the epoxy group-containing acrylic rubber by the above-mentioned (mouth) method, the carbon-carbon unsaturated bond-containing compound having an epoxy group for graft-modifying the acrylic rubber is described above. An epoxy group-containing unsaturated hydrocarbon compound, a glycidyl ester group-containing unsaturated hydrocarbon compound, a glycidyl ether group-containing unsaturated hydrocarbon compound, or the like may be used. [0041] As the above (mouth) method, for example, a carbon-carbon unsaturated bond-containing compound having the above carboxyl group and Z or epoxy group in an acrylic rubber dissolved in an organic solvent in the presence of a radical initiator. The method of making this react is mentioned.

 [0042] The carboxylic acid derivative group in the acryl rubber molecule used in preparing the carboxyl group-containing acrylic rubber by the method (c) includes a carboxylic acid ester group possessed by a (meth) acrylic acid ester monomer unit. Are preferable. For example, a carboxyl group-containing acrylic rubber can be obtained by hydrolyzing a part of the carboxylic acid ester group of an acrylic rubber dissolved in an organic solvent in the presence of hydrochloric acid, sulfuric acid, sodium hydroxide or the like.

[0043] It should be noted that the carboxyl group or epoxy group-containing acrylic rubber obtained by the above method (mouth) and the method (c) can be converted into monomer units containing carboxyl groups and Z or epoxy groups. The content of the carboxyl group of is the same as in the case of the method (ii) above.

 [0044] Mu-one viscosity (ML) of acrylic rubber containing carboxyl group or epoxy group

 1 + 4, 100 ° C

) Is preferably 10 to 90, more preferably 15 to 80, and particularly preferably 20 to 70. If the mu-one viscosity is too small, the shape-retaining property of the acrylic rubber composition may be reduced, which may reduce the moldability and the mechanical strength of the crosslinked product. On the other hand, if the Mooney viscosity is too high, the moldability may be reduced due to a decrease in fluidity.

 [0045] The ketimine structure-containing compound used in the present invention is a compound having a chemical structure represented by the following general formula (1) in the molecule.

[0046],

— ^{N = c} \ ₂ (1)

Here, R ¹ and R ² are alkyl groups having 1 to 12 carbon atoms.

[0047] Specific examples of the ketimine structure-containing compound include dimethylketoiminopropyltrimethoxysilane, dimethylketoiminopropyltriethoxysilane, methylethylketoiminopropyltrimethoxysilane, and methylketylketoiminopropyltri. Ethoxysilane, methyl isobuty Luketominopropyltrimethoxysilane, methylisobutylketoiminopropyldimethoxymethylsilane, methylisobutylketoiminopropyltriethoxymethylsilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, 3-trimethoxysilyl — Ketimine-based silane coupling agents such as N- (1,3-dimethylbutylidene) propylamine. Of these, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine and 3-trimethoxysilyl-N- (1,3-dimethylbutylidene) propylamine are preferred.

 [0048] In the rubber composition of the present invention, the effect obtained by the ketimine structure-containing compound is not always clear, but is stable at the stage of rubber yarn and composition, and heated at the stage of crosslinking reaction. It is presumed that hydrolysis with residual moisture produces an amine compound that promotes cross-linking between the carboxyl group and z or epoxy group of acrylic rubber. For this reason, it is considered that the speed of crosslinking is increased without impairing the stability of the scorch, thereby reducing the number of free crosslinking points in the crosslinked product, thereby reducing the compression set.

 [0049] The content of the ketimine structure-containing compound in the rubber composition of the present invention is preferably from 0.01 to 10 parts by weight, more preferably from 0.1 to 10 parts by weight, based on 100 parts by weight of the carboxyl group or epoxy group-containing acrylic rubber. 05 to 5 parts by weight, particularly preferably 0.1 to 2 parts by weight. If the content of the ketimine structure-containing compound is too small, the crosslinking rate of the rubber composition may not be improved. Conversely, if the content is too large, the scorch stability may be lacking.

 [0050] The carbon black used in the present invention is not particularly limited as long as it is used for blending rubber processing. For example, furnace black, acetylene black, thermal black, channel black, graphite and the like can be used.

[0051] Among these, furnace black is particularly preferred as SAF, IS AF, ISAF—HS, ISAF—LS, IISAF—HS, HAF, HAF—HS, HAF—LS, M AF ゝ. Various grades such as FEF-FEF-LS, GPF-GPF-HS-GPF-LS, SRF, SRF-HS, SRF-LM are listed. The particle size, specific surface area and oil absorption are not particularly limited. The particle size is preferably 15 to 200 nm, more preferably 18 to: LOOnm, the specific area is preferably 10 to 260 m ² / g, more preferably 20 to 240 m ² / g, and the oil absorption is preferred. Or 50 to 200 ml Zl00g, more preferably 70 to 180 ml Zl00g.

[0052] Carbon black has a function of reinforcing the cross-linked product of the present invention. The content of carbon black in the rubber composition of the present invention is preferably 20 to 200 parts by weight, more preferably 30 to 150 parts by weight, and particularly preferably 40 parts by weight based on 100 parts by weight of a carboxyl group or epoxy group-containing acrylic rubber. ~: L 00 parts by weight. If the carbon black content is too small, the strength of the resulting crosslinked product may be reduced. Conversely, if the content is too large, the elongation of the crosslinked product may be reduced.

[0053] The cross-linking agent used in the rubber composition of the present invention is not limited as long as it is a compound that can cross-link with the carboxyl group and z or epoxy group of the acrylic rubber containing carboxyl group or epoxy group.

 Examples of the carboxyl group crosslinking agent include polyvalent amine compounds, polyhydric hydrazide compounds, polyvalent epoxy compounds, polyvalent isocyanate compounds, aziridine compounds, basic metal oxides, and organometallic halides.

 [0054] Examples of the epoxy group crosslinking agent include polyvalent amine compounds, imidazole compounds, polyvalent carboxylic acid compounds, carboxylic acid ammonium salts, acid anhydrides, active hydrogen compounds, and isocyanuric acid compounds. It is done.

 [0055] The polyvalent amine compound used as a crosslinking agent for carboxyl groups or a crosslinking agent for epoxy groups preferably has 4 to 30 carbon atoms. Examples of such polyvalent amine compounds include aliphatic polyvalent amine compounds and aromatic polyvalent amine compounds, and have a non-conjugated nitrogen-carbon double bond like guanidine compounds. Things are not included.

 Aliphatic polyvalent amine compounds include hexamethylenediamine, hexamethylenediamine carbamate, N, N'-dicinnamylidene 1, 6 hexanediamin, etc.

[0056] Examples of the aromatic polyamine compound include 4,4, -methylenedialine, m-phenylenediamine, 4,4'-diaminodiphenylenoate, 3,4'-diaminodiphenolatenore. 4, 4,,-(m-Phenolenediisopropylidene) dialine, 4, 4,-(p-Dienediisopropylidene) dialine, 2, 2, 1 bis [4— (4 aminophenoxy ) Fuel] Propane, 4,4,1-diaminobenzaldehyde, 4,4,1bis (4-aminophenoxy) biphenyl, m-xy Polyvalent amine compounds such as rylenediamine, p-xylylenediamine, 1,3,5-benzenetriamine can be used alone or in combination of two or more.

[0057] Examples of the polyhydric hydrazide compound include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, dartalic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, Diacid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-Naphthalenedicarboxylic acid dihydrazide, naphthalic acid dihydrazide, acetone dicarboxylic acid dihydrazide, fumaric acid dihydrazide, maleic acid dihydrazide, itaconic acid dihydrazide Examples include acid dihydrazide, 1,3,5-benzenetricarboxylic acid dihydrazide, pyromellitic acid dihydrazide, and aconitic acid dihydrazide. These can be used alone or in combination of two or more.

[0058] Examples of the polyvalent epoxy compound include phenol novolac type epoxy compound, cresol novolac type epoxy compound, talesol type epoxy compound, bisphenol A type epoxy compound, bisphenol F type epoxy compound, brominated bisphenol A type ester. Poxy compounds, brominated bisphenol F-type epoxy compounds, hydrogenated bisphenol A-type epoxy compounds and other glycidyl ether-type epoxy compounds; alicyclic epoxy compounds, glycidyl ester-type epoxy compounds, glycidylamine types Other polyvalent epoxy compounds such as epoxy compounds and isocyanurate type epoxy compounds; compounds having two or more epoxy groups in the molecule. These can be used alone or in combination of two or more.

[0059] As the polyvalent isocyanate compound, the diisocyanates and triisocyanates having 6 to 24 carbon atoms are preferable. Specific examples of diisocyanates include 2, 4-tolylene diisocyanate (2, 4-TDI), 2,6-tolylene diisocyanate (2, 6-TDI), 4, 4'-diphenyl. Methane diisocyanate (HMDI), hexamethylene diisocyanate, p-phenolic diisocyanate, m-phenolic diisocyanate, 1,5-naphthylene diisocyanate. Specific examples of triisocyanates include 1, 3, 6-hexamethylene triisocyanate, 1, 6, 11-undecane triisocyanate, and bicyclohept. Tantriisocyanate and the like. These can be used alone or in combination of two or more.

 [0060] Examples of the aziridine compound include tris-2,4,6- (1 aziridyl) -1,3,5 triazine, tris [1- (2-methyl) aziridyl] phosphinoxide, hexa [1 — (2-Methyl) aziridinyl] triphosphatriazine. These can be used alone or in combination of two or more.

 [0061] Examples of the basic metal oxide include zinc oxide, lead oxide, calcium oxide, magnesium oxide, and the like, and these can be used alone or in combination of two or more.

 [0062] Examples of the organometallic halide include dicyclopentagenyl metal dihalides, and examples of the metal preferably used in this case include titanium, zirconium, hafnium, and the like.

 [0063] Examples of the imidazole compound include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzylimidazole, and 1 benzyl-2. -Methylimidazole, 2,4-diamino-6- [2-methylimidazoline mono (1)]-ethynole S-triazine and the like.

 [0064] Examples of the polyvalent carboxylic acid compound include aliphatic polyvalent carboxylic acids and aromatic polyvalent carboxylic acids having 3 to 20 carbon atoms.

 Examples of the aliphatic polycarboxylic acid include malonic acid, succinic acid, dartaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

 Examples of the aromatic polyvalent carboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalic acid and the like.

[0065] Examples of the carboxylic acid ammonium salt include ammonium benzoate and ammonium adipate.

 Examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, naphthalic anhydride, and the like.

Examples of the active hydrogen compound include acids, alcohols and phenols. Examples of the isocyanuric acid compound include isocyanuric acid and cyanuric acid. [0066] Among the carboxyl group crosslinking agents, aliphatic polyvalent amine compounds, aromatic polyvalent amine compounds, and polyhydric hydrazide compounds are preferred, and aliphatic polyvalent amine compounds and aromatic polyvalent amines. Particularly preferred are aliphatic and aromatic diamines in which the amine-based crosslinking agent of the compound is more preferred. Among the aliphatic diamines, hexamethylene diamine is particularly preferred, and among aromatic diamines, 2,2,1-bis [4- (4-aminophenoxy) phenol] propane is particularly preferred. I like it!

 Among epoxy group crosslinking agents, ammonium benzoate and isocyanuric acid are preferred.

 [0067] When the carboxyl group- or epoxy-group-containing acrylic rubber has a crosslinkable addition group other than a carboxyl group or an epoxy group or an unsaturated bond as a crosslinking point and also crosslinks them, the rubber composition of the present invention Can contain a crosslinking agent corresponding to the type and content of the crosslinking points.

 [0068] The content of the crosslinking agent in the rubber composition of the present invention is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 0.1 parts by weight based on 100 parts by weight of the carboxyl group and Z or epoxy group-containing rubber. LO parts by weight, particularly preferably 0.2 to 7 parts by weight. If the content of the cross-linking agent is too small, the cross-linking may be insufficient and it may be difficult to maintain the shape of the cross-linked product. On the other hand, if the amount is too large, the crosslinked product becomes too hard, and the elasticity as a crosslinked rubber may be impaired.

 [0069] The rubber composition of the present invention preferably further contains an epoxy group-containing silane coupling agent for the purpose of enhancing the scorch stability.

 [0070] The epoxy group-containing silane coupling agent preferably has the general formula X—Si (OR), or

 Three

 X—A compound represented by SiR, (OR). Where R and R are alkyl groups, X

 2

 Is an atomic group containing an epoxy group. In such a silane coupling agent, X acts as a functional group capable of reacting with a carboxyl group-containing acrylic rubber.

[0071] The epoxy group-containing silane coupling agent is preferably an aliphatic alkyl group having 1 to 8 carbon atoms containing an X force epoxy group in the above formula. The alkoxy group (—OR) in the above formula is preferably an alkoxy group having 1 to 8 carbon atoms, such as a methoxy group, an ethoxy group, and a methoxyethoxy group. In addition, the —R ′ (OR) group is Examples thereof include a methyldimethoxy group and an ethyldimethoxy group.

Specific examples of such an epoxy group-containing silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropinoletriethoxysilane, and γ-glycid.

Glycidoxy group-containing silane coupling agent such as β-glycidoxypropylmethyldimethoxysilane; Epoxycyclohexyl group-containing silane coupling agent such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane And so on. Of these, y-glycidoxypropyl trimethoxysilane and 13-glycidoxypropylmethyldimethoxysilane are particularly preferred, where glycidoxy group-containing silane coupling agents are preferred.

 [0073] The content of the epoxy group-containing silane coupling agent is preferably 0.2 to 5 parts by weight, more preferably 0.3 to 4 parts by weight with respect to 100 parts by weight of the carboxyl group or epoxy group-containing acrylic rubber. More preferably, it is 0.5 to 3 parts by weight. If the content of the epoxy group-containing silane coupling agent is too large, the elongation of the crosslinked product may be reduced.

 [0074] The acrylic rubber composition of the present invention includes a crosslinking accelerator, a processing aid, an anti-aging agent, a light stabilizer, a plasticizer, a filler (for example, silica, calcium carbonate), a lubricant, an adhesive as necessary. Additives such as additives, lubricants, flame retardants, antifungal agents, antistatic agents, colorants, fillers and the like may be included.

[0075] The cross-linking accelerator is not particularly limited. Particularly, when a polyvalent amine is used as the cross-linking agent, the cross-linking accelerator used in combination with the polyvalent amine is a base at 25 ° C in water. dissociation constant is 10 ¹² ~: it shall preferably L0 ^6. Examples of such crosslinking accelerators include aliphatic monovalent secondary amine compounds, aliphatic monovalent tertiary amine compounds, guanidine compounds, imidazole compounds, quaternary onium salts, Examples include tertiary phosphine compounds and alkali metal salts of weak acids.

 [0076] The aliphatic monovalent secondary amine compound has an aliphatic hydrocarbon group preferably having 1 to 30 carbon atoms, more preferably 8 to 20 carbon atoms.

Specifically, dimethylamine, jetylamine, dipropylamine, diarylamine, diisopropylamine, di-n-butylamine, di-t-butylamine, di-sec-butyl Amine, Dihexylamine, Diheptylamine, Dioctylamine, Dinonylamine, Didecylamine, Didecylamine, Didodecylamine, Ditridecylamine, Ditetradecylamine, Dipentadecylamine, Dicetylamine, Di-2-ethylhexylamine, Dioctadecyl, Dioctadecylamine Examples include di-cis 9-octadecylamine, dinonadecylamine and the like. Among these, dioctylamine, didecylamine, didodecylamine, ditetradecylamine, dicetylamine, dioctadecylamine, dicis-9-octadecylamine, dinonadecylamine, dicyclohexylamine and the like are preferable.

[0077] The aliphatic monovalent tertiary amine compound has an aliphatic hydrocarbon group that is substituted with three hydrogen atoms of ammonia, preferably having 1 to 30, more preferably 1 to 22 carbon atoms. . Specifically, trimethylamine, triethylamine, tripropylamine, triallylamine, triisopropylamine, tri- _n -butylamine, tri-t-butylamine, tri-sec butyramine, trihexylamine, triheptylamine, tri Octylamine, trinonylamine, tridecylamine, triunedecylamine, tridodecylamine, tritridecylamine, tritetradecylamine, tripentadecylamine, tricetylamine, tri-2-ethylhexylamine, trioctadecyl Amine, tricis-9-octadecylamine, trinonadecylamine, N, N dimethyldecylamine, N, N dimethyldodecylamine, N, N dimethyltetradecylamine, N, N dimethylcetylamine, N, N Dimethyloctadecylamide N, N Dimethylbenzylamine, N-methyldidecylamine, N-methyldidodecylamine, N-methylditetradecylamine, N-methyldiscetylamine, N-methyldioctadecylamine, N- Examples thereof include methyldibe-lamine, dimethylcyclohexylamine and the like. Among these, N, N dimethyldodecylamine, N, N dimethyltetradecylamine, N, N dimethyl cetylamine, N, N dimethyloctadecylamine, N, N dimethyl berylamine and the like are preferable.

 [0078] Examples of the guanidine compound include 1,3 di-o-tolyl guanidine, 1,3 diphenyl guanidine, and the like.

 Examples of the imidazole compound include 2-methylimidazole and 2-phenolimidazole.

Quaternary o-um salts include tetra-n-butylammo-um bromide and octadeci. Lutri n-butylammo-um bromide.

[0079] Examples of the tertiary phosphine compound include triphenylphosphine, tri-p-tolylphosphine, and the like.

 Examples of alkali metal salts of weak acids include inorganic weak acid salts such as sodium or potassium phosphates and carbonates, or organic weak acid salts such as stearates and laurates.

 [0080] The amount of the crosslinking accelerator used is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 15 parts by weight, particularly preferably 100 parts by weight of the acrylic rubber containing carboxyl group or epoxy group. Is 0.3 to 10 parts by weight. If the amount of the crosslinking accelerator is too large, the crosslinking rate may become too fast at the time of crosslinking, the crosslinking accelerator may bloom on the surface of the crosslinked product, or the crosslinked product may become too hard. If the amount of the crosslinking accelerator is too small, the tensile strength of the crosslinked product may be remarkably lowered, or the elongation and the change in tensile strength after heat load may be too large.

 [0081] In addition, the rubber composition of the present invention may be blended with a polymer such as rubber other than the acrylic rubber, elastomer, and resin if necessary.

 Examples of the compoundable rubber include natural rubber, acrylic rubber not containing a carboxyl group, nitrile rubber, styrene butadiene rubber, polybutadiene rubber, and polyisoprene rubber.

 [0082] Examples of elastomers that can be blended include olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, polysiloxane-based elastomers, and the like.

 Examples of the resin that can be blended include olefin-based resin, styrene-based resin, acrylic resin, polyphenylene ether, polyester, polycarbonate, and polyamide.

 [0083] As a method for preparing the rubber composition of the present invention, a mixing method such as roll mixing, Banbury mixing, screw mixing, and solution mixing can be appropriately employed. The order of blending is not particularly limited, but after sufficiently mixing components that are not easily reacted or decomposed by heat, components that are easily reacted by heat or components that are easily decomposed, such as crosslinking agents and crosslinking accelerators, are reacted or reacted. Mix in a short time at temperature, without decomposition!

[0084] The rubber composition of the present invention has excellent scorch stability, and has a high strength and a high crosslinking rate. Yes. Therefore, it is excellent in productivity with a short molding cycle.

 [0085] The crosslinked product of the present invention is obtained by molding and crosslinking the rubber composition of the present invention described above by a molding method such as extrusion molding, injection molding, transfer molding, compression molding or the like.

[0086] A general rubber processing procedure can be employed for extrusion molding. In other words, a rubber composition prepared by roll mixing or the like is supplied to the feed port of the extruder and softened by heating from the barrel in the process of being sent to the head part with a screw, so that a predetermined shape provided in the head part is obtained. By passing through a die, a long extruded product (plate, bar, pipe, hose, deformed product, etc.) having the desired cross-sectional shape is obtained.

 [0087] In injection molding, transfer molding, and compression molding, the mold composition having a shape corresponding to one or several products is filled with the rubber composition of the present invention and shaped, and the mold is preferably used. Preferably, crosslinking (primary crosslinking) is performed by heating to 130 to 220 ° C, more preferably 140 to 200 ° C to obtain a crosslinked product (primary crosslinked product).

 Furthermore, if necessary, the crosslinked product is heated at 130 ° C to 220 ° C, more preferably 140 ° C to 200 ° C for 1 to 48 hours in an oven using electricity, hot air, steam or the like as a heat source. A secondary cross-linked product is obtained as a cross-linked product (secondary cross-linked product).

 Example

 [0088] The present invention will be specifically described below with reference to production examples, examples and comparative examples. However, the present invention is not limited to these examples.

 [Part] in these examples is based on weight unless otherwise specified. The test and evaluation were performed according to the following methods.

 (1) Carboxyl group content

 The carboxyl group content of acrylic rubber was determined by titrating an acetone solution in which acrylic rubber was dissolved with a potentiometric titrator COMTITE-101 (manufactured by Hiranuma Sangyo Co., Ltd.) using a 0.01N ethanol solution of potassium hydroxide, and the carboxyl group relative to rubber lOOg. (Number of moles, unit is ephr).

[0089] (2) Epoxy group content

The epoxy group content of acrylic rubber is a methyl ethyl ketone solution in which acrylic rubber is dissolved. After adding 0.01N acetone solution and reacting with epoxy group at about 40 ° C for 3 hours, the remaining hydrochloric acid was titrated using potentiometric titration with 0.01N ethanol solution of potassium hydroxide. It was titrated with Oki COMTITE-101 (manufactured by Hiranuma Sangyo Co., Ltd.) to determine the number of epoxy groups (mole number, unit: ephr) relative to rubber lOOg.

 (3) Mooney viscosity

 The mu-one viscosity ML of rubber at a measurement temperature of 100 ° C. was measured according to the mu-one viscosity test of the uncrosslinked rubber physical test method of JISK6300.

 1 + 4

 [0090] (4) Scorch stability (Mooney scorch)

 The Mooney scorch of the rubber composition was measured using an L-shaped rotor at a temperature of 125 ° C. according to JISK 6300-1. From this measurement result, the Mooney scorch time t5 (min) of the rubber composition was determined. The greater the value of t5 (min), the better the scorch stability.

 (5) Cross-linking properties

 In accordance with JISK6300-2 mm, measurements were made using a rotorless rheometer type vibration crosslinking tester. Torque was measured at a temperature of 180 ° C for 8 minutes, and the cross-linking characteristics were evaluated by determining the maximum torque MH (dN'm). The larger the value of MH (dN'm), the higher the crosslinking speed and the faster the bridge speed, and the better the molding cycle (productivity).

[0091] (6) Normal physical properties

 The rubber composition was molded and primary cross-linked by compression molding at 180 ° C for 6 minutes to produce a sheet 15cm long, 15cm wide and 2mm thick, and then left in an electric oven at 170 ° C for 4 hours for secondary treatment. Cross-linking was performed to obtain a sheet-like cross-linked product. Next, this sheet-like cross-linked product was punched with a No. 3 dumbbell, and normal properties were evaluated by measuring tensile strength and elongation according to JISK6251 at room temperature using the test pieces prepared.

[0092] (7) Heat resistance

 A test piece obtained in the same manner as in (4) above was placed in an environment at a temperature of 150 ° C. for 72 hours, and then the tensile strength and elongation were measured according to JISK6251.

In evaluating the heat resistance, the tensile strength and elongation were determined as the rate of change (percentage) of the measured value after heating with respect to the measured value of the normal physical properties. The closer these values are to 0, the better the heat resistance. [0093] (8) Compression set

 (4) Cylindrical cross-linked product in the same manner as the cross-linked product for measurement of normal physical properties, except that a cylindrical mold with an inner diameter of 29 mm and a height of 12.5 mm was used and heating of the primary cross-linking was performed at 180 ° C for 8 minutes. Was used as a test piece. The obtained test piece was placed in a 150 ° C environment for 72 hours in a state of being compressed by 25% according to JISK6262, and then the compression was released and the compression set was measured. The compression set rate is better as the numerical value is smaller and the material is more difficult to deform.

 [0094] (Production Example 1) Production of carboxyl group-containing acrylic rubber (Rubber A)

 In a polymerization reactor equipped with a thermometer and a stirrer, 200 parts of ion exchange water, 3 parts of sodium lauryl sulfate, 10 parts of ethyl acrylate, 50 parts of mono-n-butyl acrylate, 35 parts of 2-methoxyethyl acrylate and fumar Charge 5 parts of mono-n-butyl acid. After degassing and substituting with nitrogen twice to sufficiently remove oxygen, add 0.055 parts cumene hydride peroxide and 0.002 parts sodium formaldehyde sulfoxylate and add under normal pressure at a temperature of 30 ° C. Emulsion polymerization was started and the reaction was continued until the polymerization conversion reached 95% by weight. The resulting polymerization solution was coagulated with an aqueous calcium chloride solution, filtered, washed with water and dried to obtain a carboxylinole group-containing attalinole rubber (rubber A).

[0095] The composition of the rubber A obtained was 10% ethenyl acrylate monomer unit, 50% n-butyl acrylate monomer unit, 35% 2-methoxyethyl acrylate monomer unit, and fumarate mono an n- butyl monomeric units 5% (content of carboxyl group 1. 08 X 10- ² ephr [rubber 100g per equivalent]), arm one - a viscosity (ML

 1 + 4, 100 ° C) was 35.

 [0096] (Production Example 2) Production of epoxy group-containing acrylic rubber (Rubber B)

Polymerization was carried out in the same manner as in Production Example 1 except that the type and amount of the monomer used for the polymerization were changed. Ethyl acrylate monomer unit 40%, n-butyl acrylate monomer unit 38%, An epoxy group-containing acrylic rubber (rubber B) having 20% 2-methoxyethyl acrylate monomer units and 2% glycidyl methacrylate monomer units was obtained. Epoxy group content 1. a 0 X 10- ² ephr, arm one - A viscosity (ML

 1 + 4, 100 ° C) was 40.

 [Example 1]

Rubber A: 100 parts, FEF carbon black (SEAST SO, manufactured by Tokai Carbon Co., Ltd., reinforcing agent): 60 parts, stearic acid (strengthening aid): 2, 4, 4, bis (α, a-dimethyl) Benzyl) Diph Nylamine (Norack CD, Ouchi Shinsei Co., Ltd., anti-aging agent): 2 parts, glycidoxy group-containing silane coupling agent Ί-glycidoxypropyltrimethoxysilane: 1 part and ketimine structure-containing 3 Triethoxysilyl-N— (1,3 dimethylbutylidene) propylamine (the following general formula (2)): 1 part is put into a Banbury mixer and kneaded at 50 ° C, and then into an open roll. transferred by 2, 2 'single-bis [4 i (4 one aminophenoxy) full E - le] propane (crosslinking agent): 1 part and 1, _3-di o Torirugua - Jin (Nocceler _DT

, Manufactured by Ouchi Shinsei Chemical Co., Ltd., crosslinking accelerator): 1 part was added and kneaded at 40 ° C to prepare rubber composition A.

 Scorch stability and crosslinking characteristics of the obtained rubber composition, and normal properties (tensile strength and elongation), heat resistance and compression set of the crosslinked product obtained by crosslinking the rubber composition Tested and evaluated. The results are shown in Table 1.

 [0098]

C ₂ H ₃

IH ₃

 0 I

1 ^ CH ₂ — Cii — CH ₃

C ₂ H ₅ O—— ¾—— C ₃ H ₆ —— N = C \ (2)

I, CH ₃

 o

 t

C ₂ H ₅

[0099] (Example 2)

 In Example 1, γ-glycidoxypropyltrimethoxysilane, which is a glycidoxy group-containing silane coupling agent, is not used, but 3-triethoxysilyl-Ν- (1,3 dimethylbutylidene) propylamine is a ketimine structure-containing compound. A rubber composition was prepared in the same manner as in Example 1 except that the amount was changed to 0.5 part, and tested and evaluated in the same manner as in Example 1. The results are shown in Table 1.

 [0100] (Example 3)

Rubber Β: 100 parts, HAF carbon black (Seast 3, manufactured by Tokai Carbon Co., Ltd., reinforcing agent): 65 parts, stearic acid (processing aid): 0.5 parts, 4, 4, bis (α, a— Dimethylbenzyl) diphenylamine (NOCRACK CD, manufactured by Ouchi Shinsei Chemical Co., Ltd., anti-aging agent): 2 parts, 3 triethoxysilyl-N- (1,3 dimethylbutylidene) propylamine: 1 part Banburymi Kneaded at 50 ° C and then transferred to an open roll and isocyanuric acid (ZEON ETA, Nippon Zeon Co., Ltd., cross-linking agent): 0.6 part and stearyltrimethylammonum bromide (ZEONETBF, Nippon Zeon Co., Ltd.) , Crosslinking accelerator): 1. 8 parts and diphenol-rea (ZEONETU, manufactured by Nippon Zeon Co., Ltd., scorch inhibitor) were added and kneaded at 40 ° C. to prepare rubber composition B. The obtained rubber composition was tested and evaluated in the same manner as in Example 1. The results are shown in Table 1.

 [0101] (Comparative Example 1)

 The rubber composition was the same as in Example 1, except that γ-glycidoxypropyltrimethoxysilane and 3-triethoxysilyl-Ν- (1,3-dimethylbutylidene) propylamine were added in Example 1. A product was prepared and tested and evaluated in the same manner as in Example 1. The results are shown in Table 1.

 [0102] (Comparative Example 2)

 In Example 1, 3-triethoxysilyl mono- (1,3-dimethylbutylidene) propylamine, which is a ketimine structure-containing compound, was not used, and γ-a was used as the amino group-containing silane coupling agent. A rubber composition was prepared in the same manner as in Example 1 except that 1 part of minopropyltriethoxysilane was added, and tested and evaluated in the same manner as in Example 1. The results are shown in Table 1.

 [0103] (Comparative Example 3)

 The rubber composition in Example 3 was the same as in Example 3 except that 3-triethoxysilyl mono (1,3-dimethylbutylidene) propylamine, which is a compound containing ketimine structure, was used. A product was prepared and tested and evaluated in the same manner as in Example 1. The results are shown in Table 1.

表 1が示すように、カルボキシル基含有アクリルゴム（ゴム A)にケチミン構造含有化 合物を配合した実施例 1および 2では、同じゴム Aを用いてケチミン構造含有ィ匕合物 を配合していない比較例 1に比して、最大トルク MHが高くなつたことから、ゴム組成 物はスコーチ安定性に優れ、し力も架橋速度が速いことが確認できる。実施例 1およ び 2の架橋物は、常態物性の引っ張り強さが大きぐ耐熱性も良好で、また、圧縮永 久ひずみが小さい。グリシドキシ基含有シランカップリング剤を添加することにより、ス コーチが長くなり、さらに最大トルク MHがより高くなることから、成形加工性が非常に 優れることが判る（実施例 1と 2との対比)。ケチミン構造含有化合物に代えて、ァミノ 基含有シラン化合物を用いた場合、スコーチ安定性が低下している (比較例 2)。 [0104] [Table 1]

As shown in Table 1, in Examples 1 and 2 in which the ketimine structure-containing compound was blended with the carboxyl group-containing acrylic rubber (rubber A), the ketimine structure-containing compound was blended using the same rubber A. Since the maximum torque MH was higher than that of Comparative Example 1 It can be confirmed that the product is excellent in scorch stability and has a fast crosslinking speed. The crosslinked products of Examples 1 and 2 have a high tensile strength of normal properties, a good heat resistance, and a small compression set. By adding a glycidoxy group-containing silane coupling agent, the scorch becomes longer and the maximum torque MH becomes higher, so it can be seen that the molding processability is very good (contrast with Examples 1 and 2). . When an amino group-containing silane compound is used in place of the ketimine structure-containing compound, the scorch stability is reduced (Comparative Example 2).

[0106] The rubber composition of Example 3 in which the epoxy group-containing acrylic rubber (rubber B) was blended with the ketimine structure-containing compound was also blended with the ketimine structure-containing compound. In contrast, Mooney scorch t5 has a slightly shorter force Maintaining good scorch stability, maximum torque MH is higher, and cross-linked products have higher tensile strength and lower compression set. Speak.

 Industrial applicability

[0107] The cross-linked product (primary cross-linked product or secondary cross-linked product) of the rubber composition of the present invention maintains the basic properties of an acrylic rubber such as tensile strength, elongation, and hardness, and has a compression set. Is small.

 For this reason, this cross-linked product is used in a wide range of fields such as transportation equipment such as automobiles, general equipment, and electrical equipment. It is preferably used as a covering material; industrial belts; tubes, hoses; sheets;

Claims

The scope of the claims  [1] A rubber composition comprising an acrylic rubber containing at least one group selected from a carboxyl group and an epoxy group, a ketimine structure-containing compound, carbon black and a crosslinking agent.  [2] The acrylic rubber containing at least one group selected from a carboxyl group and an epoxy group is a polymer containing 70% by weight or more of a (meth) acrylate monomer unit. The rubber composition as described.  [3] (meth) acrylic acid ester monomer unit is (meth) acrylic acid alkyl ester monomer The rubber composition according to claim 1, wherein the rubber composition is a unit derived from at least one monomer force selected from (1) and (meth) acrylic acid alkoxyalkyl ester monomers. [4] The total content of carboxyl group and an epoxy group of the acrylic rubber containing at least one group forces were also selected in the carboxyl group and epoxy group, or those of the rubber 100 g, 4 X 10- ⁴ to 4 X a rubber composition according to claim 1 10 ¹ is equivalent. [5] The acrylic rubber containing at least one group selected from among carboxyl group and an epoxy group, containing (I) (meth) acrylic acid ester monomer units 70 wt _^0/0 or more, and et al A copolymer containing at least one monomer unit selected from a carboxyl group-containing monomer unit and an epoxy group-containing monomer unit; (mouth) (meth) acrylic acid ester monomer unit Is contained in a carbon-carbon unsaturated bond-containing compound having a carboxyl group and a carbon-carbon unsaturated bond-containing compound having an epoxy group with respect to a polymer having neither a carboxyl group nor an epoxy group. A polymer obtained by grafting at least one compound selected from the group consisting of: (c) (meth) acrylic acid ester monomer units containing 70% by weight or more and carboxylic acid 5. The rubber composition according to claim 1, wherein a part of the carboxylic acid derivative group of the polymer containing a derivative group is converted into a carboxyl group by hydrolysis.  [6] Mu-one viscosity (ML) of acrylic rubber containing at least one selected group of carboxyl group and epoxy group  The rubber composition according to any one of claims 1 to 5, which has a force of 1 to 4 and 100 ° C) of 10 to 90. [7] A ketimine structure-containing compound has the following general formula (1):

The rubber composition according to any one of claims 1 to 6, which is a compound having a chemical structure represented by (wherein R ¹ and R ² are alkyl groups having 1 to 12 carbon atoms).  [8] The content of the ketimine structure-containing compound is 0.01 to 10 parts by weight with respect to 100 parts by weight of an acrylic rubber containing at least one group selected from a carboxyl group and an epoxy group. Item 8. A rubber composition according to any one of Items 1 to 7.  [9] The rubber composition according to any one of [1] to [8], wherein the carbon black is one selected from among furnace black, acetylene black, thermal black, channel black, and graphite.  [10] Carbon black content power Medium power of carboxyl group and epoxy group 20 to 200 parts by weight per 100 parts by weight of acrylic rubber containing at least one selected group. The rubber composition as described in 2.  [11] Middle force of carboxyl group and epoxy group The acrylic rubber containing at least one selected group is an acrylic rubber containing a carboxyl group, and the crosslinking agent is a polyvalent amine compound, a polyhydric hydrazide The rubber composition according to any one of claims 1 to 10, which is selected from a compound, a polyvalent epoxy compound, a polyvalent isocyanate compound, an aziridine compound, a basic metal oxide, and an organometallic halide. object.  [12] The acrylic rubber containing at least one kind of the selected group of carboxyl group and epoxy group is an acrylic rubber containing an epoxy group, and the crosslinking agent is a polyvalent amine compound, an imidazole compound, The rubber composition according to any one of claims 1 to 10, which is selected from among polyvalent carboxylic acid compounds, carboxylic acid ammonium salts, acid anhydrides, active hydrogen compounds and isocyanuric acid compounds. object.  [13] The rubber composition according to any one of [1] to [10], wherein the crosslinking agent is a polyvalent amine compound crosslinking agent. [14] The content of the cross-linking agent is at least selected between the carboxyl group and the epoxy group The rubber composition according to any one of claims 1 to 13, which is 0.05 to 20 parts by weight with respect to 100 parts by weight of an acrylic rubber containing one kind of group. [15] The rubber composition according to any one of claims 1 to 14, further comprising an epoxy group-containing silane coupling agent. [16] The epoxy group-containing silane coupling agent has the general formula  X-Si (OR) or X—SiR, (OR)  3 2  16. The rubber composition according to claim 15, wherein R and R ′ are alkyl groups, and X is an atomic group containing an epoxy group. [17] Content power of epoxy group-containing silane coupling agent Acrylic rubber containing at least one kind of selected carboxyl group and epoxy group medium force The rubber composition according to claim 15 or 16, which is 0.2 to 5 parts by weight. [18] The present invention further comprises 0.1 to 20 parts by weight of a crosslinking accelerator with respect to 100 parts by weight of acrylic rubber containing at least one kind of group selected from among carboxyl groups and epoxy groups. The rubber composition according to any one of -17. [19] Water, a base dissociation constant = 25 ° C in the 10- ¹² ~: a crosslinking accelerator is L0 ^6, acryl rubber 100 weight containing at least one group forces were also selected in the carboxyl group and an epoxy group 19. The rubber composition according to claim 18, containing 0.1 to 20 parts by weight with respect to parts. [20] A crosslinked product obtained by crosslinking the rubber composition according to any one of claims 1 to 19.