JP2019026662A - Crosslinking composition - Google Patents

Abstract

To provide a rubber material that comprises an epichlorohydrin polymer and has excellent dynamic characteristics (e.g. it has low dynamic-to-static moduli while maintaining excellent damping performance), and a composition for the rubber material.SOLUTION: The present invention provides a crosslinking composition containing (A) epichlorohydrin polymer, (B) acrylic polymer, and (C) crosslinker, and a rubber material prepared from the crosslinking composition.SELECTED DRAWING: None

Description

  The present invention relates to a crosslinking composition comprising an epichlorohydrin polymer and an acrylic polymer as essential components, and a rubber material obtained by crosslinking the composition. Hereinafter, the material obtained by crosslinking may be referred to as “crosslinked rubber material”.

  In the fields of buildings, aircraft, automobiles, railway vehicles, computers, automobile tires, etc., materials mainly using natural rubber are used for the purpose of vibration isolation. However, the natural rubber material has a problem that heat resistance and ozone resistance are insufficient. Therefore, for improving heat resistance, a technique using EPDM which has no double bond in the main chain and has excellent heat resistance is disclosed (Patent Documents 1 and 2).

  Epichlorohydrin rubber materials using epichlorohydrin polymers are widely used as fuel hoses, air hoses, and tube materials in automotive applications, taking advantage of their heat resistance, oil resistance, ozone resistance and the like.

  However, epichlorohydrin rubber materials are not sufficiently low in dynamic magnification and are used as materials for vibration isolation in the fields of buildings, aircraft, automobiles, railway vehicles, computers, automobile tires, etc. There wasn't.

JP 2005-113093 A JP 2009-298949 A

  To provide a rubber material having excellent dynamic characteristics using an epichlorohydrin polymer (having a low dynamic magnification while maintaining good damping properties), and a composition for the rubber material Let it be an issue.

  The inventors have found (A) an epichlorohydrin polymer, (B) an acrylic polymer, (C) a crosslinking composition containing a crosslinking agent, and a rubber material produced from the crosslinking composition. It was.

That is, the crosslinking composition and rubber material of the present invention that have solved the above problems are as follows.
Item 1 A crosslinking composition comprising (A) an epichlorohydrin polymer, (B) an acrylic polymer, and (C) a crosslinking agent.
Item 2 The crosslinking composition according to Item 1, wherein the (B) acrylic polymer has a structural unit derived from an unsaturated monomer having a halogen group.
Item 3 The crosslinking composition according to Item 1 or 2, wherein the (C) crosslinking agent is a dechlorinated crosslinking agent.
Item 4 (C) The crosslinking composition according to any one of Items 1 to 3, wherein the crosslinking agent is a triazine-based crosslinking agent or a thiourea-based crosslinking agent.
Item 5. A rubber material produced from the crosslinking composition according to any one of Items 1 to 4.
Item 6 An automotive hose material, a tube material, a mount material, and a seal material produced from the rubber material according to Item 5.

  The rubber material obtained by the present invention is produced from an epichlorohydrin polymer and an acrylic polymer, so that it has good heat resistance and excellent dynamic characteristics, and both characteristics are required at the same time. It is suitable as a mounting material. In addition, there is an effect that there is little influence due to temperature change.

  Hereinafter, the rubber composition obtained by crosslinking the crosslinking composition and the crosslinking composition of the present invention will be described in detail. The crosslinking composition of the present invention contains (A) an epichlorohydrin polymer, (B) an acrylic polymer, and (C) a crosslinking agent.

The (A) epichlorohydrin polymer used in the crosslinking composition of the present invention has a ring opening as a structural unit derived from epichlorohydrin (—CH ₂ —CH (CH ₂ Cl) —O—). A ring-opening polymer of epichlorohydrin, specifically a ring-opening polymer of epichlorohydrin and a monomer copolymerizable with epichlorohydrin, and epichlorohydrin- Examples include ring-opening polymers of alkylene oxides, ring-opening polymers of epichlorohydrin-glycidyls, and ring-opening polymers of epichlorohydrin-alkylene oxides-glycidyls, and epichlorohydrin rubber and It can also be described. Monomers copolymerizable with epichlorohydrin include alkylene oxides such as ethylene oxide, propylene oxide, and n-butylene oxide, methyl glycidyl ether, ethyl glycidyl ether, n-glycidyl ether, allyl glycidyl ether, and phenyl glycidyl ether. And the like.

  (A) The epichlorohydrin-based polymer preferably contains 40 mol% or more of a structural unit derived from epichlorohydrin, more preferably contains 50 mol% or more, and particularly preferably contains 70 mol% or more. Preferably, it may contain 97 mol% or less, and may contain 95 mol% or less.

  (A) As an epichlorohydrin-type polymer, the minimum of the structural unit derived from alkylene oxide may contain 3 mol% or more, may contain 5 mol% or more, and contains 60 mol% or less. Is preferable, it is more preferable to contain 50 mol% or less, and it is especially preferable to contain 30 mol% or less.

  (A) As an epichlorohydrin polymer, the minimum of the structural unit derived from glycidyls may contain 1 mol% or more, may contain 2 mol% or more, and contains 10 mol% or less. Is more preferable, 8 mol% or less is more preferable, and 5 mol% or less is particularly preferable.

  In the present application, the molar ratio derived from each structural unit in the (A) epichlorohydrin polymer is applied as it is if it is composed of a single polymer, and may be composed of a plurality of polymers. For example, it can be calculated from the molar ratio of each polymer and the ratio in mass occupied by each polymer in the (A) epichlorohydrin polymer.

  (A) When the epichlorohydrin polymer is composed of a plurality of polymers, epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer 1 type of these homopolymers or copolymers, such as a polymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer, epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymer, Or it can be used in combination of two or more.

The copolymer composition of epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer is determined by the chlorine content and iodine value.
Chlorine content is measured by potentiometric titration according to the method described in JIS K7229. The molar fraction of the structural unit derived from epichlorohydrin is calculated from the obtained chlorine content.
The iodine value is measured by a method according to JIS K6235. The mole fraction of the structural unit derived from allyl glycidyl ether is calculated from the obtained iodine value.
The mole fraction of the structural unit derived from ethylene oxide is calculated from the mole fraction of the structural unit derived from epichlorohydrin and the mole fraction of the structural unit derived from allyl glycidyl ether.

The molecular weight of the (A) epichlorohydrin polymer is not particularly limited, but may be any molecular weight that is usually about ML _{1 + 4} (100 ° C.) = 30 to 150 in Mooney viscosity display.

  The epichlorohydrin polymer can be produced by a solution polymerization method, a slurry polymerization method, or the like at a temperature in the range of -20 to 100 ° C. using a catalyst capable of ring-opening polymerization of an oxirane compound. As such a catalyst, for example, a catalyst system in which organic aluminum is mainly used and this is reacted with water or phosphorus oxo acid compound or acetylacetone, a catalyst system in which organic zinc is mainly used and water is reacted therewith, organic tin- Examples include phosphate ester condensate catalyst systems. For example, the epichlorohydrin polymer of the present invention can be produced using the organotin-phosphate ester condensate catalyst system described in US Pat. No. 3,773,694 by the present applicant. In addition, when making it copolymerize by such a manufacturing method, it is preferable to copolymerize these components substantially randomly.

  The (B) acrylic polymer used in the rubber composition for crosslinking of the present invention is a polymer having a structural unit derived from an acrylate ester, and can also be described as an acrylic rubber.

(B) The acrylic polymer preferably has a structural unit derived from an alkyl acrylate ester and / or a structural unit derived from an alkoxyalkyl acrylate ester, and an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms. It is preferable to have a structural unit derived from an ester derived from an ester and / or an acrylic acid alkoxyalkyl ester having an alkoxyalkyl group having 2 to 8 carbon atoms, and an alkyl acrylate ester having an alkyl group having 2 to 6 carbon atoms. It is more preferable to have a structural unit derived from an acrylic acid alkoxyalkyl ester having a structural unit derived from and / or an alkoxyalkyl group having 2 to 6 carbon atoms, and an alkyl acrylate ester having an alkyl group having 2 to 4 carbon atoms Structural units and / or carbon number derived from Particularly preferably has a constituent unit derived from an alkoxyalkyl acrylate ester having to 4 alkoxyalkyl group.
Specific examples of structural units derived from alkyl acrylate esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, and acrylic. Examples of the structural unit derived from an acrylate ester such as n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, etc. include ethyl acrylate, acrylic acid n A structural unit derived from -butyl is preferable.
Specific examples of structural units derived from alkoxyalkyl acrylates include methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, 2-ethoxyethyl acrylate, 2-propoxyethyl acrylate, and 2-butoxy acrylate. Derived from acrylic esters such as ethyl, 2-methoxypropyl acrylate, 2-ethoxypropyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 4-methoxybutyl acrylate, 4-ethoxybutyl acrylate, etc. And a structural unit derived from methoxyethyl acrylate is preferable.

  In the (B) acrylic polymer of the present invention, the content of the structural unit derived from the acrylate ester is 5 to 99.9% by mass in the total structural unit of the (B) acrylic polymer, It is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, still more preferably 50% by mass or more, and 70% by mass or more. Is particularly preferably 99.5% by mass or less, and particularly preferably 99% by mass or less.

  In the (B) acrylic polymer of the present invention, the content of the structural unit derived from the acrylic acid alkyl ester is more than 30% by mass in the total structural unit of the (B) acrylic polymer. Preferably, it is more preferably 40% by mass or more, and particularly preferably 50% by mass or more.

  The (B) acrylic polymer of the present invention preferably has a structural unit derived from an unsaturated monomer having a crosslinking group, and the unsaturated group has a halogen group (for example, a chlorine group) as the crosslinking group. The structural unit derived from the body, the structural unit derived from the unsaturated monomer having a carboxyl group, the structural unit derived from the unsaturated monomer having an epoxy group can be exemplified, and the structural unit derived from a unsaturated group having a halogen group (particularly a chlorine group). A structural unit derived from a saturated monomer is particularly preferred.

  Examples of the unsaturated monomer having a halogen group include 2-chloroethyl vinyl ether, 2-chloroethyl acrylate, vinyl benzyl chloride, vinyl monochloroacetate, and allyl chloroacetate.

  Examples of unsaturated monomers having a carboxyl group include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, 2-pentenoic acid and cinnamic acid, and unsaturated acids such as fumaric acid, maleic acid and itaconic acid. Dicarboxylic acid, maleic anhydride, carboxylic anhydrides such as citraconic anhydride, butenedionate mono, such as monomethyl fumarate, monoethyl fumarate, mono n-butyl fumarate, monomethyl maleate, monoethyl maleate, mono n-butyl maleate Chain alkyl esters; butenedionic acid monocyclic alkyl esters such as monocyclopentyl fumarate, monocyclohexyl fumarate, monocyclopentyl maleate, monocyclohexyl maleate; monomethyl itaconate, monoethyl itaconate, mono n-butyl itaconate, itaconic acid Mo Itaconic acid monoesters, such as cyclohexyl; and the like. Among these, unsaturated dicarboxylic acid monoesters such as monoethyl fumarate, monopropyl fumarate, monobutyl fumarate, monoethyl itaconate, monopropyl itaconate, monobutyl itaconate and the like can be mentioned.

  Examples of the unsaturated monomer having an epoxy group include glycidyl (meth) acrylate and (meth) allyl glycidyl ether.

  When the structural unit derived from the unsaturated monomer having a crosslinking group is contained, the content ratio of the structural unit in the acrylic polymer is preferably 0.1% by mass or more, and 0.3% by mass or more. More preferably, it is particularly preferably 0.5% by mass or more, preferably 15% by mass or less, more preferably 12% by mass or less, and particularly preferably 10% by mass or less. .

  Furthermore, the acrylic polymer of this invention may contain the other monomer structural unit copolymerizable with these in addition to said structural unit. As other structural units, structural units derived from methacrylic acid esters, structural units derived from ethylenically unsaturated nitriles, structural units derived from (meth) acrylamide monomers, structural units derived from aromatic vinyl monomers, conjugated diene monomers Examples include a structural unit derived from, a structural unit derived from non-conjugated dienes, a structural unit derived from esters, and a structural unit derived from other olefinic monomers.

  Methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, and n-methacrylate. Methacrylic acid alkyl esters such as heptyl, n-octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, methoxymethyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, 2-ethoxyethyl methacrylate, 2-methacrylic acid 2- Propoxyethyl, 2-butoxyethyl methacrylate, 2-methoxypropyl methacrylate, 2-ethoxypropyl methacrylate, 3-methoxypropyl methacrylate, 3-methacrylic acid 3- Tokishipuropiru, 4-methoxybutyl methacrylate, methacrylic acid alkoxyalkyl esters such as methacrylic acid 4-ethoxy-butyl

  Examples of the ethylenically unsaturated nitrile include acrylonitrile, methacrylonitrile, α-methoxyacrylonitrile, vinylidene cyanide and the like.

  Examples of (meth) acrylamide monomers include acrylamide, methacrylamide, diacetone acrylamide, diacetone methacrylamide, N-butoxymethyl acrylamide, N-butoxymethyl methacrylamide, N-butoxyethyl acrylamide, N-butoxyethyl methacrylamide, N -Methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-propoxymethylacrylamide, N-propoxymethylmethacrylamide, N-methylacrylamide, N-methylmethacrylamide, N, N-dimethylacrylamide, N, N-dimethyl Methacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, Takuriruamido, crotonamide, cinnamic acid amide, maleic diamide, Itakonjiamido, methyl maleate amide, methyl itaconate amides, maleimide, itaconimide, and the like.

  Examples of aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, α-fluorostyrene, p-trifluoromethylstyrene, p-methoxy. Styrene, p-aminostyrene, p-dimethylaminostyrene, p-acetoxystyrene, styrenesulfonic acid or its salt, α-vinylnaphthalene, 1-vinylnaphthalene-4-sulfonic acid or its salt, 2-vinylfluorene, 2- Examples include vinyl pyridine, 4-vinyl pyridine, divinyl benzene, diisopropenyl benzene, and vinyl benzyl chloride.

  Conjugated diene monomers include 1,3-butadiene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,2-dichloro-1,3-butadiene, and 2,3-dichloro -1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-neopentyl-1,3-butadiene, 2-bromo-1,3-butadiene, 2-cyano-1,3-butadiene, 1 , 3-pentadiene, 1,3-hexadiene, chloroprene, piperylene and the like.

  Non-conjugated dienes include 1,4-pentadiene, 1,4-hexadiene, ethylidene norbornene, norbornadiene, dicyclopentadiene, and the like.

  Esters include dicyclopentanyl acrylate, dicyclopentanyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxyethyl methacrylate, and the like. .

  Other olefinic monomers include ethylene, propylene, vinyl chloride, vinylidene chloride, 1,2-dichloroethylene, vinyl acetate, vinyl fluoride, vinylidene fluoride, 1,2-difluoroethylene, vinyl bromide, vinylidene bromide, 1,2-dibromoethylene, ethyl vinyl ether, butyl vinyl ether and the like can be mentioned.

  When these other copolymerizable monomer constituent units are contained, the content ratio is 0 to 45% by mass, may be 1% by mass or more, and may be 2% by mass or more. 20 mass% or less, or 10 mass% or less.

  (B) The glass transition temperature of the acrylic polymer is preferably −70 ° C. or higher, more preferably −50 ° C. or higher, preferably −10 ° C. or lower, and −20 ° C. or lower. It is more preferable.

  (B) The acrylic polymer may be composed of a plurality of different acrylic polymers, and two or more acrylic polymers having structural units derived from unsaturated monomers having different crosslinking groups are used in combination. Can also be used.

<Method for producing acrylic polymer>
The acrylic polymer used in the present invention can be obtained by polymerizing the various known monomers. Any of the monomers used may be a commercially available product and is not particularly limited.

  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 polymer is used. It is preferable to use an emulsion polymerization method under normal pressure, which is generally used as a method for producing a coalescence.

  In the case of polymerization by emulsion polymerization, conventional methods may be used, and conventionally known polymerization initiators, emulsifiers, chain transfer agents, polymerization terminators and the like that are generally used can be used.

  The emulsifier used in the present invention is not particularly limited, and nonionic emulsifiers, anionic emulsifiers and the like generally used in emulsion polymerization methods can be used. Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether, polyoxyethylene alcohol ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polycyclic phenyl ether, polyoxyalkylene alkyl ether, sorbitan fatty acid ester, polyoxyethylene fatty acid ester and Polyoxyethylene sorbitan fatty acid esters and the like, and as anionic emulsifiers, alkylbenzene sulfonates, alkyl sulfate esters, polyoxyethylene alkyl ether sulfate esters, polyoxyalkylene alkyl ether phosphate esters or salts thereof, fatty acid salts , Sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, dodecyl sulfate triethanolamine, etc. It may be used alone or in combination.

  The amount of the emulsifier used in the present invention may be an amount generally used in the emulsion polymerization method. Specifically, it is preferably in the range of 0.01 to 10% by mass, more preferably 0.03% by mass or more, still more preferably 0.05% by mass or more, and more preferably, with respect to the monomer amount charged. It is 7 mass% or less, More preferably, it is 5 mass% or less. When a reactive surfactant is used as the monomer component, it is not always necessary to add an emulsifier.

  The polymerization initiator used by this invention is not specifically limited, The polymerization initiator generally used in an emulsion polymerization method can be used. Specific examples thereof include inorganic peroxide polymerization initiators represented by persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, 2,2-di (4,4-di- (t-butyl). Peroxy) cyclohexyl) propane, 1-di- (t-hexylperoxy) cyclohexane, 1,1-di- (t-butylperoxy) cyclohexane, 4,4-di- (t-butylperoxy) valeric acid n-butyl, 2,2-di (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3 -Tetramethylbutyl hydroperoxide, t-butylcumyl peroxide, di-t-butyl peroxide, -T-hexyl peroxide, di (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, diisobutyryl peroxide, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, Disuccinic acid peroxide, dibenzoyl peroxide, di (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (4- t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, cumylperoxyneodecanate, 1,1,3,3-tetramethylbutane Luperoxyneodecanate, t-hexylperoxyneodecanate, t-butylperoxyneodecanate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5- Di (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, t-hexylperoxy-2-ethylhexanate, t-butylperoxy- 2-ethylhexanate, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanate, t-hexylperoxyisopropylmonocarbonate, t-butylperoxyisopropylmonocarbonate, t- Butyl peroxy 2-ethylhexyl monocarbonate, 2,5-dimethyl -2,5-di (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxybenzoate, 2,5-dimethyl-2,5-di (t-butylperoxy) Oxy) organic peroxide polymerization initiators such as hexane, hydroperoxide, azobisisobutyronitrile, 4-4′-azobis (4-cyanovaleric acid), 2-2′-azobis [2- ( 2-Imidazolin-2-yl) propane, 2-2'-azobis (propane-2-carboamidine) 2-2'-azobis [N- (2-carboxyethyl) -2-methylpropanamide, 2-2 ' -Azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane}, 2-2'-azobis (1-imino-1-pyrrolidino-2-me Trimethylolpropane) and 2-2'-azobis {2-methyl-N-[1,1-bis (hydroxymethyl) -2-hydroxyethyl] propanamide} like azo-based polymerization initiators, and the like. These polymerization initiators may be used alone or in combination of two or more.

  The amount of the polymerization initiator used in the present invention may be an amount generally used in the emulsion polymerization method. Specifically, the amount is preferably 0.01 to 5% by mass, more preferably 0.01% by mass or more, still more preferably 0.02% by mass or more, and more preferably 4% by mass or less, based on the amount of monomer charged. More preferably, it is 3% by mass or less.

  Moreover, the organic peroxide and inorganic peroxide as a polymerization initiator can be used as a redox polymerization initiator by combining with a reducing agent. Although it does not specifically limit as a reducing agent used in combination, Compounds containing metal ions in a reduced state such as ferrous sulfate and cuprous naphthenate; Methane compounds such as sodium methanesulfonate; Amines such as dimethylaniline Ascorbic acid and its salts; inorganic salts having reducibility such as alkali metal salts of sulfurous acid and thiosulfuric acid. These reducing agents can be used alone or in combination of two or more. The amount of the reducing agent used is preferably 0.0003 to 10.0 parts by mass with respect to 100 parts by mass of the peroxide.

  A chain transfer agent can be used as needed. Specific examples of the chain transfer agent include n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan and other alkyl mercaptans, 2,4-diphenyl-4 -Xanthogen compounds such as methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene, dimethylxanthogen disulfide, diisopropylxanthogen disulfide, terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram mono Thiuram compounds such as sulfide, phenol compounds such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol, allyl compounds such as allyl alcohol, di Halogenated hydrocarbon compounds such as lormethane, dibromomethane, carbon tetrabromide, vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile, α-benzyloxyacrylamide, triphenylethane, pentaphenylethane, acrolein, methacrolein , Thioglycolic acid, thiomalic acid, 2-ethylhexyl thioglycolate, and the like, and these may be used alone or in combination. The amount of these chain transfer agents is not particularly limited, but is usually 0 to 5 parts by mass with respect to 100 parts by mass of the charged monomer amount.

  Examples of the polymerization terminator include hydroxylamine, hydroxyamine sulfate, diethylhydroxyamine, hydroxyaminesulfonic acid and its alkali metal salt, sodium dimethyldithiocarbamate and the like. Although the usage-amount of a polymerization terminator is not specifically limited, Usually, it is 0-2 mass parts with respect to 100 mass parts of monomer amounts of preparation.

  Furthermore, the polymer obtained by the above method can be adjusted in pH by using a base as a pH adjuster as necessary. Specific examples of the base include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, inorganic ammonium compounds, organic amine compounds and the like. The pH range is preferably pH 1 to 11, more preferably pH 1.5 or more, still more preferably pH 2 or more, more preferably pH 10.5 or less, still more preferably pH 10 or less.

  Other than these, if necessary, polymerization auxiliary materials such as a particle size adjusting agent, a chelating agent, and an oxygen scavenger can be used.

  The emulsion polymerization may be any of batch, semi-batch and continuous. The polymerization time and polymerization temperature are not particularly limited. Although it can select suitably from the kind etc. of the polymerization initiator to be used, generally polymerization temperature is 20-100 degreeC and superposition | polymerization time is 0.5 to 100 hours.

The molecular weight range of the acrylic polymer used in the present invention produced as described above is preferably expressed as Mooney viscosity (ML _{1 + 4} ) at 100 ° C. in the Mooney scorch test defined in JIS K 6300, preferably 10 to 100. More preferably, it is 15 or more, More preferably, it is 20 or more, More preferably, it is 90 or less, More preferably, it is 80 or less.

  In the crosslinking composition of the present invention, the mass ratio (A / B) of (A) epichlorohydrin polymer and (B) acrylic polymer is preferably 5/95 to 95/5, It is more preferable that it is 20/80 to 80/20, and it is preferable that it is 30/70 to 70/30.

  In the crosslinking composition of the present invention, examples of the crosslinking agent (C) include a dechlorinating crosslinking agent that is a crosslinking agent that utilizes the reactivity of chlorine atoms, and a crosslinking agent that utilizes the reactivity of side chain double bonds. It is done. Examples of the dechlorination crosslinking agent that is a crosslinking agent that utilizes the reactivity of chlorine atoms include polyamine crosslinking agents, thiourea crosslinking agents, thiadiazole crosslinking agents, triazine crosslinking agents, quinoxaline crosslinking agents, bisphenol crosslinking agents, etc. Examples of the crosslinking agent that utilizes the reactivity of the side chain double bond include organic peroxide crosslinking agents, sulfur, morpholine polysulfide crosslinking agents, thiuram polysulfide crosslinking agents, and the like. It is preferably a dechlorinated crosslinking agent that is a crosslinking agent that utilizes the reactivity of atoms, and in terms of the balance between low dynamic power and damping, it is preferably a thiourea crosslinking agent or a triazine crosslinking agent. In terms of dynamic magnification, a triazine-based crosslinking agent is preferable. (C) A crosslinking agent may be used individually by 1 type, or may be used in combination of 2 or more types.

Examples of the polyamine-based crosslinking agent include ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, p-phenylenediamine, cumenediamine, N, N′-dicinnamylidene-1,6-hexanediamine, ethylenediamine carbamate, hexamethylene. Examples include diamine carbamate.
Examples of the thiourea crosslinking agent include 2-mercaptoimidazoline (ethylene thiourea), 1,3-diethylthiourea, 1,3-dibutylthiourea, trimethylthiourea and the like.
Examples of thiadiazole-based crosslinking agents include 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-1,3,4-thiadiazole-5-thiobenzoate and the like.
Examples of triazine crosslinking agents include 2,4,6-trimercapto-1,3,5-triazine, 2-hexylamino-4,6-dimercaptotriazine, 2-diethylamino-4,6-dimercaptotriazine, 2 -Cyclohexylamino-4,6-dimercaptotriazine, 2-dibutylamino-4,6-dimercaptotriazine, 2-anilino-4,6-dimercaptotriazine, 2-phenylamino-4,6-dimercaptotriazine, etc. Is mentioned.
Examples of quinoxaline crosslinking agents include 2,3-dimercaptoquinoxaline, quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline-2,3-dithiocarbonate, 5,8-dimethylquinoxaline-2,3-dithiocarbonate, and the like. Is mentioned.
Examples of the bisphenol crosslinking agent include bisphenol AF and bisphenol S.
Examples of the organic peroxide crosslinking agent include tert-butyl hydroperoxide, p-menthane hydroperoxide, dicumyl peroxide, tert-butyl peroxide, 1,3-bis (tert-butylperoxyisopropyl) benzene, Examples include 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, benzoyl peroxide, tert-butylperoxybenzoate, and the like.
Examples of the morpholine polysulfide crosslinking agent include morpholine disulfide.
Examples of the thiuram polysulfide crosslinking agent include tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, dipentamethylene thiuram tetrasulfide, dipentamethylene thiuram hexasulfide and the like.

  In the crosslinking composition of the present invention, the content of the (C) crosslinking agent is 0.1 with respect to a total of 100 parts by mass of the (A) epichlorohydrin polymer and the (B) acrylic polymer. It is preferable that it is 10 parts by mass or more. The lower limit is particularly preferably 0.3 parts by mass or more, and the upper limit is particularly preferably 5 parts by mass or less.

  As long as the effects of the present invention are not impaired, the crosslinking composition of the present invention includes compounding agents other than those described above, such as acid acceptors, lubricants, anti-aging agents, antioxidants, ultraviolet absorbers and light stabilizers. Additives, reinforcing agents, plasticizers, processing aids, flame retardants, cross-linking accelerators, cross-linking retarders, peptizers and the like can be further optionally blended. Furthermore, it is possible to perform blending of rubber, resin, etc., which is usually performed in the technical field, as long as the characteristics of the present invention are not lost.

  In the crosslinking composition of the present invention, a known (D) acid acceptor can be used depending on the crosslinking agent, and a metal compound and / or an inorganic microporous crystal is used.

  Metal compounds include Group II of the Periodic Table (Group 2 and Group 12 metal oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites, Periodic Table Group IV. (Group 4 and Group 14) non-lead metal oxides, basic carbonates, basic carboxylates, basic phosphites, basic sulfites, tribasic sulfates and the like. It is done.

  Specific examples of the metal compound include magnesium oxide, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, sodium carbonate, quicklime, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate , Calcium phosphite, zinc white, tin oxide, tin stearate, basic tin phosphite, and the like. Particularly preferred acid acceptors include magnesium oxide, calcium carbonate, slaked lime, and quicklime.

  The inorganic microporous crystal means a crystalline porous body, and can be clearly distinguished from an amorphous porous body such as silica gel, alumina and the like. Examples of such inorganic microporous crystals include zeolites, alumina phosphate type molecular sieves, layered silicates, hydrotalosites, alkali metal titanates and the like. Particularly preferred acid acceptors include hydrotalcites.

  Zeolites are natural zeolite, A-type, X-type, Y-type synthetic zeolite, sodalite, natural or synthetic mordenite, various zeolites such as ZSM-5, and metal substitutes thereof. It may be used or a combination of two or more. Further, the metal of the metal substitution product is often sodium. As the zeolite, those having a large acid-accepting ability are preferable, and A-type zeolite is preferable.

The hydrotalcite is represented by the following general formula (1)
_{Mg X Zn Y Al Z (OH} ) (2 (X + Y) + 3Z-2) CO 3 · wH 2 O (1)
[Wherein, x and y are each a real number of 0 to 10 having a relation of x + y = 1 to 10, z is a real number of 1 to 5, and w is a real number of 0 to 10, respectively].
Specific examples of the _{hydrotalcite, Mg 4.5 Al 2 (OH)} 13 CO 3 · 3.5H 2 O, Mg 4.5 Al 2 (OH) 13 CO 3, Mg 4 Al 2 (OH) 12 CO _{3 · 3.5H 2 O, Mg 5} Al 2 (OH) 14 CO 3 · 4H 2 O, Mg 3 Al 2 (OH) 10 CO 3 · 1.7H 2 O, Mg 3 ZnAl 2 (OH) 12 CO 3 _{· 3.5H 2 O, Mg 3 ZnAl} 2 (OH) may be mentioned _{12 CO 3, Mg 4.3 Al 2} (OH) 12.6 CO 3 · 3.5H 2 O and the like.

  In the crosslinking composition of the present invention, the content of the (D) acid acceptor is 0.000 based on a total of 100 parts by mass of the (A) epichlorohydrin polymer and the (B) acrylic polymer. It is preferably 2 to 50 parts by mass, particularly preferably 1 to 20 parts by mass. (D) If content of an acid acceptor is this range, a crosslinked material will not become too rigid and the physical property normally anticipated as a crosslinked material will be obtained.

  Specific examples of the lubricant include paraffins and hydrocarbon resins such as paraffin wax and hydrocarbon wax; fatty acids such as stearic acid and palmitic acid; fatty acid amides such as stearamide and oleyl amide; n-butyl -Fatty acid ester, such as a stearate; Sorbitan fatty acid ester; Fatty alcohol; etc. are mentioned, These may be used individually by 1 type and may use 2 or more types together.

  As the anti-aging agent, known amine-based anti-aging agents, phenol-based anti-aging agents, benzimidazole-based anti-aging agents, dithiocarbamate-based anti-aging agents, thiourea-based anti-aging agents, organic thio acid-based anti-aging agents And phosphorous acid type antioxidants are exemplified, and these may be used alone or in combination of two or more. Preferred are amine-based anti-aging agents, phenol-based anti-aging agents, benzimidazole-based anti-aging agents, and dithiocarbamate-based anti-aging agents, and more preferred are dithiocarbamate-based anti-aging agents.

  Examples of the plasticizer include phthalic acid derivatives such as dioctyl phthalate, adipic acid derivatives such as dibutyl diglycol-adipate and di (butoxyethoxy) ethyl adipate, sebacic acid derivatives such as dioctyl sebacate, and trioctyl trimellitate. A merit acid derivative etc. are mentioned, These may be used individually by 1 type and may use 2 or more types together.

  As the peptizer, aromatic mercaptan compounds, aromatic disulfide compounds, aromatic mercaptan metal compounds, or mixed compounds thereof can be used, and typically o, o-dibenzamide diphenyl disulfide. Is mentioned.

  Examples of the carbon black used in the crosslinking composition of the present invention include furnace black, acetylene black, thermal black, channel black, and graphite. Specifically, SAF, ISAF, HAF, EPC, XCF, FEF, GPF, HMF, SRF, FT, and MT can be exemplified. These carbon blacks may be used alone or in combination of two or more.

The carbon black, the nitrogen adsorption specific surface area (N2SA) is preferably ^{5 m} 2 / g or more, more preferably more than ^7m 2 / g, more ^{10 m} 2 / g is particularly preferred. The upper limit is preferably 180 m ² / g or less from the viewpoint of easy availability.

  The carbon black preferably has a dibutyl phthalate (DBP) oil absorption of 15 ml / 100 g, more preferably 20 ml / 100 g or more, particularly preferably 30 ml / 100 g or more. The upper limit is preferably 175 ml / 100 g, more preferably 170 ml / 100 g, from the viewpoint of easy availability.

  In the crosslinking composition of the present invention, the carbon black content is 5 parts by mass or more with respect to a total of 100 parts by mass of the (A) epichlorohydrin polymer and the (B) acrylic polymer. Is preferably 7 parts by mass or more, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less.

  In order to produce the crosslinking composition according to the present invention, any mixing means conventionally used in the field of polymer processing, such as a mixing roll, a Banbury mixer, various kneaders, and the like can be used.

  The rubber material of the present invention is produced from the crosslinking composition of the present invention. Specifically, since it is obtained by crosslinking, it can also be described as a crosslinked product or a crosslinked rubber material.

  The rubber material of the present invention is usually obtained by heating to 100 to 200 ° C. The crosslinking time varies depending on the temperature, but is usually between 0.5 and 300 minutes. As a method of cross-linking molding, any method such as compression molding using a mold, injection molding, steam can, air bath, infrared ray, or heating using microwaves can be used.

  The rubber material of the present invention can be suitably used for anti-vibration rubber such as rubber for railway vehicles, rubber for industrial machinery, rubber for automobiles such as mounts, etc., particularly with heat resistance, low dynamic magnification and damping. It is suitably used for a mount material with excellent balance.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to this description.

  The glass transition temperature (Tg) of the acrylic polymer used in the examples and comparative examples was measured by using a differential scanning calorimeter “DSC8000” manufactured by Perkin Elmer Co., Ltd. The temperature was lowered to −80 ° C. at a rate of 10 ° C./min, held at that temperature for 1 minute, and then the glass transition temperature (Tg) was determined from the thermogram when the temperature was raised to 60 ° C. at 10 ° C./min.

  Each material was kneaded with a kneader and an open roll with the formulation shown in Tables 1 to 3 to prepare an uncrosslinked rubber sheet having a thickness of 2 to 2.5 mm. The uncrosslinked rubber sheet was press-crosslinked at 170 ° C. for 15 minutes, and further heated in an air oven at 150 ° C. for 2 hours to obtain a crosslinked product.

The dynamic characteristics of the crosslinked product were measured with a dynamic servo manufactured by Ashinomiya Seisakusho. The measurement conditions are a temperature of 23 ° C., a relative humidity of 50%, and a static spring constant (Ks) is a ratio of a static load and a displacement in a section of 1 to 2 mm when the test piece is compressed to 0 to 3 mm. Kd) is the ratio of dynamic load to displacement when the preset compression ratio of the test piece is 5%, the strain amplitude is ± 0.1%, and the frequency is 100 Hz. The ratio (Kd / (Ks)) between the dynamic spring constant (Kd) and the static spring constant (Ks) is evaluated as a dynamic magnification. The lower the dynamic magnification, the better. The results are shown in Tables 4-6.
The attenuation of the crosslinked product was measured with a dynamic servo manufactured by Ashinomiya Seisakusho Co., Ltd., and evaluated according to the following evaluation criteria. The results are shown in Tables 4-6. The measurement conditions are tan δ when the temperature is 23 ° C., the relative humidity is 50%, the preset compression rate of the dynamic measurement specimen is 5%, the strain amplitude is 0.25 mm, and the frequency is 15 Hz.
○: tan δ is 0.20 or more ×: tan δ is less than 0.20

Viscoelastic property test A test piece having a width of 4 mm, a length of 40 mm and a thickness of 2 mm is punched from the cross-linked product, and dynamic characteristics are obtained with a DMS6100 manufactured by Seiko Instruments Inc. under an initial load of 1000 mN, a tensile strain of 10 μm, and a vibration frequency of 15 Hz. (Loss tangent: tan δ) was measured. The measurement temperature range was −80 ° C. to 150 ° C., and the temperature was increased at a rate of 2 ° C./min. The absolute value of the difference between tan δ at 23 ° C. (normal state) and tan δ at −25 ° C. (low temperature) was evaluated according to the following evaluation criteria, and the results are shown in Tables 4-6.
○: absolute value of tan δ difference is less than 0.25 ×: absolute value of tan δ difference is 0.25 or more

The compounding materials used in Examples and Comparative Examples in Tables 1 to 3 are shown below.
* 1 “Epichlorohydrin homopolymer: Epichromer H” manufactured by Osaka Soda Co., Ltd.
* 2 "Acrylic polymer (ethyl acrylate-butyl acrylate-methoxyethyl acrylate-monochlorovinyl acetate copolymer, glass transition temperature -42 ° C) manufactured by Osaka Soda Co., Ltd .: Lacrester AUC"
* 3 “Surface acrylic polymer (ethyl acrylate-butyl acrylate-methoxyethyl acrylate-monochlorovinyl acetate copolymer, glass transition temperature-41 ° C.) manufactured by Osaka Soda Co., Ltd .: Lacrester AUC-2”
* 4 “Seast TA” manufactured by Tokai Carbon Co., Ltd. ((N2SA) is 19 m ² / g, DBP oil absorption is 42 ml / 100 g)
* 5 “Seast SO” manufactured by Tokai Carbon Co., Ltd. ((N2SA) is 42 m ² / g, DBP oil absorption is 115 ml / 100 g)

  From Examples 1 to 9 in Tables 4 to 6, the rubber material obtained by crosslinking the crosslinking composition of the present invention is excellent in low dynamic magnification while maintaining the damping property, and is affected by viscoelasticity due to temperature change. Less was shown.

  According to the present invention, it is possible to provide a rubber material excellent in low dynamic magnification using an epichlorohydrin polymer. Therefore, it can be suitably used for vibration-proof rubbers such as rubber for railway vehicles, rubber for industrial machines, rubber for automobiles such as mounts, etc. from the crosslinking composition and rubber material of the present invention. It is suitably used for a mount material that has an excellent balance with damping properties.

Claims (6)

  A crosslinking composition containing (A) an epichlorohydrin polymer, (B) an acrylic polymer, and (C) a crosslinking agent.   (B) The composition for crosslinking according to claim 1, wherein the acrylic polymer has a structural unit derived from an unsaturated monomer having a halogen group.   (C) The crosslinking composition according to claim 1 or 2, wherein the crosslinking agent is a dechlorinated crosslinking agent.   (C) The crosslinking composition according to any one of claims 1 to 3, wherein the crosslinking agent is a triazine-based crosslinking agent or a thiourea-based crosslinking agent.   The rubber material produced from the composition for bridge | crosslinking in any one of Claims 1-4.   An automotive hose material, a tube material, a mount material, and a seal material produced from the rubber material according to claim 5.