TW201817801A - Acrylic rubber and crosslinked rubber product - Google Patents

Abstract

Provided are: an acrylic rubber containing an anionic emulsifier in an amount of 10-4,500 weight ppm inclusive; and a crosslinked rubber product using the acrylic rubber. According to the present invention, an acrylic rubber capable of providing a crosslinked rubber product which has high tensile strength, excellent compression set resistance and excellent water resistance and a crosslinked rubber product using the same can be provided.

Description

Acrylic rubber and its manufacturing method, acrylic rubber composition and rubber crosslinked product

The present invention relates to acrylic rubber and rubber cross-linked products, and more specifically, it relates to acrylic rubbers which provide rubber cross-linked materials with high tensile strength, compression resistance and excellent water resistance, and rubbers using the same. Cross-linking.

Acrylic rubber is a polymer containing acrylate as a main component. It is generally known as a rubber having excellent heat resistance, oil resistance, and ozone resistance, and is widely used in automobile-related fields.

Generally, such an acrylic rubber is produced by subjecting a monomer mixture constituting the acrylic rubber to emulsion polymerization, adding a coagulant to the obtained emulsion polymerization solution to agglomerate it, and drying the agglomerated water-containing pellets. (For example, refer to Patent Document 1: Japanese Patent Laid-Open No. 7-145291).

On the other hand, in recent years, among various components for automobiles such as sealing materials, hose materials, shock-proof materials, pipes, tapes, and dust-proof covers, in addition to excellent heat resistance and oil resistance, compression resistance is also required. Excellent permanent deformation and water resistance. However, conventional acrylic rubbers such as the acrylic rubber described in Patent Document 1 may not have sufficient water resistance, and therefore, the demand for water resistance has not been satisfied in recent years.

In view of such circumstances, an object of the present invention is to provide an acrylic rubber that imparts a rubber crosslinked product having high tensile strength, compression set resistance, and water resistance, and a rubber crosslinked product using the acrylic rubber.

The present inventors have devoted themselves to research in order to achieve the above-mentioned object, and as a result, they have found that the above-mentioned object can be achieved by setting the amount of the anionic emulsifier contained in the acrylic rubber to a specific range, and have completed the present invention.

That is, according to the present invention, there can be provided an acrylic rubber whose content of the anionic emulsifier is 10 ppm by weight or more and 4,500 ppm by weight or less.

In the acrylic rubber of the present invention, the content of the non-ionic emulsifier is preferably from 10 ppm by weight to 20,000 ppm by weight, and more preferably from 10 ppm by weight to 15,000 ppm by weight.

In the acrylic rubber of the present invention, the content of the coagulant is preferably 10 ppm by weight or more and 9,000 ppm by weight or less, and more preferably 10 ppm by weight or more and 3,500 ppm by weight or less.

In the acrylic rubber of the present invention, the content of the slip agent is preferably 0.1 to 0.4% by weight, and more preferably 0.2 to 0.3% by weight.

In the acrylic rubber of the present invention, the content of the anti-aging agent is preferably 500 ppm by weight or more, and more preferably 12,000 ppm by weight or less.

In the acrylic rubber of the present invention, the content of the acrylic rubber component is preferably 95% by weight or more.

The acrylic rubber of the present invention is preferably a unit containing a monomer having a halogen atom.

In addition, according to the present invention, there can be provided a method for manufacturing acrylic rubber, which is a method for manufacturing the above-mentioned acrylic rubber and includes the following steps: an emulsification polymerization step, which is used to form the aforementioned acrylic rubber in the presence of an anionic emulsifier The monomers are subjected to emulsion polymerization to obtain an emulsion polymerization solution; and a coagulation step, in which a coagulant is added to the aforementioned emulsion polymerization solution to agglomerate to obtain water-containing pellets.

In the method for producing an acrylic rubber of the present invention, it is preferable that the emulsification polymerization step is performed in such a manner that the monomer is subjected to emulsion polymerization in the presence of a nonionic emulsifier and the anionic emulsifier.

The method for manufacturing the acrylic rubber of the present invention preferably further includes an addition step, wherein the emulsification polymerization solution contains the slip agent and the anti-aging agent before the aggregation.

It is preferred that the method for producing an acrylic rubber of the present invention further includes an addition step in which the emulsifier polymerization solution contains the lubricant and the ethylene oxide polymer before the aggregation.

The method for producing the acrylic rubber of the present invention preferably further includes an addition step in which the anti-aging agent and the ethylene oxide-based polymer are contained in the emulsion polymerization solution before coagulation.

The method for producing the acrylic rubber of the present invention preferably further includes an addition step, wherein the emulsification polymerization solution contains the lubricant, the anti-aging agent, and the ethylene oxide polymer before the aggregation.

Furthermore, according to the present invention, an acrylic rubber composition containing the above-mentioned acrylic rubber and a cross-linking agent, and a rubber cross-linked product, which is obtained by cross-linking such an acrylic rubber composition, can be provided.

According to the present invention, it is possible to provide an acrylic rubber which imparts a rubber crosslinked material having high tensile strength, compression resistance and excellent water resistance, and a high tensile strength and compression resistance obtained by using such an acrylic rubber. Rubber crosslinked material with excellent permanent deformation and water resistance.

＜ Acrylic rubber ＞

The acrylic rubber of the present invention contains (meth) acrylic acid ester monomers [acrylic acid ester monomers and / Or methacrylate monomer. The same applies to the following methyl (meth) acrylate. A rubbery polymer of a unit and the content of the anionic emulsifier is 10 ppm by weight or more and 4,500 ppm by weight or less.

The (meth) acrylic acid ester monomer which is a (meth) acrylic acid ester monomer unit which forms the main component of the acrylic rubber of this invention is not specifically limited, For example, a (meth) acrylic acid alkyl ester monomer, and ( Alkoxyalkyl meth) monomers and the like.

The (meth) acrylic acid alkyl ester monomer is not particularly limited, but is preferably an ester formed from an alkanol having 1 to 8 carbon atoms and (meth) acrylic acid. Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate , Isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate. Among them, ethyl (meth) acrylate and n-butyl (meth) acrylate are preferable, and ethyl acrylate and n-butyl acrylate are more preferable. These can be used alone or in combination of two or more.

The alkoxyalkyl (meth) acrylate monomer is not particularly limited, but is preferably an ester formed from an alkoxyalkyl alcohol having 2 to 8 carbon atoms and (meth) acrylic acid. Specifically, for example, methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate Ester, 2-propoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, and 4-methoxybutyl (meth) acrylate Wait. Among them, 2-ethoxyethyl (meth) acrylate and 2-methoxyethyl (meth) acrylate are preferred, and 2-ethoxyethyl acrylate and 2-methoxyethyl acrylate are preferred. good. These can be used alone or in combination of two or more.

In the acrylic rubber of the present invention, the content of the (meth) acrylate monomer unit is usually 50 to 99.9% by weight, preferably 60 to 99.5% by weight, and most preferably 70 to 99.5% by weight. If the content of the (meth) acrylate monomer unit is too small, the weather resistance, heat resistance, and oil resistance of the obtained rubber crosslinked material may be reduced; on the other hand, if it is too large, the obtained rubber The heat resistance of the crosslinked product may be reduced.

In the acrylic rubber of the present invention, as the (meth) acrylate monomer unit, 30 to 100% by weight of the (meth) acrylate monomer unit and an (meth) acrylate alkoxy group are used. The alkyl ester monomer unit is preferably 70 to 0% by weight.

In addition to the alkyl (meth) acrylate monomer unit, the acrylic rubber of the present invention may contain a crosslinkable monomer unit as required. The crosslinkable monomer that forms the crosslinkable monomer unit is not particularly limited, and examples include: α, β-ethylene unsaturated carboxylic acid monomers; monomers having an epoxy group; monomers having a halogen atom; Diene monomer; etc. Among them, from the viewpoint of greatly improving the characteristics by setting the content of the anionic emulsifier to the range specified in the present invention, the crosslinkable monomer unit is preferably one containing a monomer unit having a halogen atom. .

The α, β-ethylene unsaturated carboxylic acid monomer is not particularly limited, and examples thereof include α, β-ethylene unsaturated monocarboxylic acid having 3 to 12 carbon atoms, and α, β-ethylene unsaturated having 4 to 12 carbon atoms. Monoesters formed from a saturated dicarboxylic acid, an α, β-ethylene unsaturated dicarboxylic acid having 4 to 12 carbon atoms, and an alkanol having 1 to 8 carbon atoms. By using an α, β-ethylene unsaturated carboxylic monomer, the acrylic rubber is made into a carboxyl group-containing acrylic rubber having a carboxyl group as a crosslinking point, and thus, in the case of being a rubber crosslinked product, it can be further improved. Compression resistance.

Specific examples of the α, β-ethylene unsaturated monocarboxylic acid having 3 to 12 carbon atoms include acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, and cinnamic acid.

Specific examples of the α, β-ethylene unsaturated dicarboxylic acid having 4 to 12 carbon atoms include butenedioic acids such as fumaric acid and maleic acid; itaconic acid; citraconic acid; Chloromaleic acid; etc.

Specific examples of the monoester formed from an α, β-ethylene unsaturated dicarboxylic acid having 4 to 12 carbons and an alkanol having 1 to 8 carbons include monomethyl fumarate, fumarate Maleic acid monoethyl ester, maleic fumarate mono-n-butyl ester, maleic acid mono-methyl ester, maleic acid mono-ethyl ester, maleic acid mono-n-butyl ester, etc. Alkyl alkanoate; fumaric acid monocyclopentyl ester, fumaric acid monocyclohexyl ester, fumaric acid monocyclohexene ester, maleic acid monocyclopentyl ester, maleic acid Acid monocyclohexyl ester, maleic acid monocyclohexenyl ester, and other butylic acid monoesters having an alicyclic structure; monomethyl iconate, monoethyl iconate, mono-n-butyl iconate , Iconic acid monocyclohexyl esters and other Iconic acid monoesters; etc.

Among them, monoesters formed by α, β-ethylene unsaturated dicarboxylic acids having 4 to 12 carbons and alkanols having 1 to 8 carbons are preferred, and butadiene acid single-chain alkyl esters, or Butadiene monoesters having an alicyclic structure are preferred, and fumaric acid mono-n-butyl ester, maleic acid mono-n-butyl ester, fumaric acid mono-cyclohexyl ester, and maleic acid are preferred. Monocyclohexyl diacid is more preferred, and mono-n-butyl fumarate is particularly preferred. These α, β-ethylene unsaturated carboxylic acid monomers may be used singly or in combination of two or more kinds. In addition, among the above-mentioned monomers, dicarboxylic acids also include those that exist in the form of acid anhydride.

The monomer having an epoxy group is not particularly limited, and examples thereof include epoxy-containing (meth) acrylates such as glycidyl (meth) acrylate; allyl glycidyl ether and vinyl groups Epoxy group-containing ethers and the like; and the like.

The monomer having a halogen atom is not particularly limited, and examples thereof include esters formed of a halogen-containing saturated carboxylic acid and an unsaturated alcohol, a halogenated (meth) acrylate, and a halogenated (meth) acrylate. Haloacyloxyalkyl (meth) acrylate, (haloacetylcarbamoyloxy) alkyl (meth) acrylate, halogen-containing unsaturated ethers, halogen-containing Unsaturated ketones, aromatic vinyl compounds containing a halogenated methyl group, unsaturated halogenated amines containing halogen, and unsaturated monomers containing an ethyl halogenated group.

Specific examples of the ester formed from a halogen-containing saturated carboxylic acid and an unsaturated alcohol include vinyl chloroacetate, vinyl 2-chloropropionate, and allyl chloroacetate.

Specific examples of the haloalkyl (meth) acrylate include chloromethyl (meth) acrylate, 1-chloroethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, and (meth) 1,2-dichloroethyl acrylate, 2-chloropropyl (meth) acrylate, 3-chloropropyl (meth) acrylate, and 2,3-dichloropropyl (meth) acrylate.

Specific examples of the halooxyalkyl (meth) acrylate include 2- (chloroethylfluorenyloxy) ethyl (meth) acrylate, and 2- (chloroethylfluorenyloxy) propyl (meth) acrylate. , 3- (chloroethylacetoxy) propyl (meth) acrylate, and 3- (hydroxychloroethylacetoxy) propyl (meth) acrylate.

Specific examples of the (meth) acrylic acid (halogenated ethylamidomethylformoxy) alkyl ester include 2- (chloroethylamidomethylformoxy) ethyl (meth) acrylate, and (methyl) ) 3- (Chloroethylammoniummethylformoxy) propyl acrylate and the like.

Specific examples of the halogen-containing unsaturated ethers include chloromethyl vinyl ether, 2-chloroethyl vinyl ether, 3-chloropropyl vinyl ether, 2-chloroethyl allyl ether, and 3-chloropropyl allyl ether and the like.

Specific examples of the halogen-containing unsaturated ketones include 2-chloroethyl vinyl ketone, 3-chloropropyl vinyl ketone, and 2-chloroethyl allyl ketone.

Specific examples of the halogenated methyl-containing aromatic vinyl compound include p-chloromethylstyrene, m-chloromethylstyrene, o-chloromethylstyrene, and p-chloromethyl-α-methylstyrene.

Specific examples of the halogen-containing unsaturated amidines include N-chloromethyl (meth) acrylamido and the like.

Specific examples of the unsaturated monomer containing a halogenated acetamyl group include 3- (hydroxychloroethylacetoxy) propylallyl ether, p-vinylbenzyl chloroacetate, and the like.

Examples of the diene monomer include a conjugated diene monomer and a non-conjugated diene monomer.

Specific examples of the conjugated diene monomer include 1,3-butadiene, isoprene, and 1,3-pentadiene.

Specific examples of the non-conjugated diene monomer include ethylene norbornene, dicyclopentadiene, dicyclopentadienyl (meth) acrylate, and (meth) Base) 2-dicyclopentadienylethyl acrylate and the like.

In the case where an α, β-ethylene unsaturated carboxylic monomer is used in the above-mentioned crosslinkable monosystem, the acrylic rubber can be made into an acrylic rubber containing a carboxyl group. By making the acrylic rubber containing a carboxyl group, the acrylic rubber can have good oil resistance and heat resistance, and can further improve compression set resistance. In the case where a monomer having a halogen atom is used in the above-mentioned crosslinkable single system, the acrylic rubber can be made into an acrylic rubber containing a halogen atom. By making the acrylic rubber containing halogen-containing acrylic rubber, the oil resistance and heat resistance can be improved, and the tensile strength can be further improved.

In the acrylic rubber of the present invention, the content of the crosslinkable monomer unit is preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight, and even more preferably 0.5 to 5% by weight. By setting the content of the crosslinkable monomer unit within the above range, the mechanical properties and heat resistance of the obtained rubber crosslinked product can be made good, and the compression set resistance can be more appropriately improved.

In addition to the (meth) acrylic acid ester monomer unit and the crosslinkable monomer unit used as required, the acrylic rubber of the present invention may have other monomer units that can be copolymerized with the acrylic rubber. Examples of such other copolymerizable monomers include aromatic vinyl monomers, α, β-ethylene unsaturated nitrile monomers, acrylic amine-based monomers, and other olefin-based monomers.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, and divinylbenzene.

Examples of the α, β-ethylene unsaturated nitrile monomer include acrylonitrile, methacrylonitrile, and the like.

Examples of the acrylamide-based monomer include acrylamide, methacrylamide, and the like.

Examples of other olefin-based monomers include ethylene, propylene, vinyl chloride, vinylidene chloride, vinyl acetate, ethyl vinyl ether, and butyl vinyl ether.

Among other monomers that can be copolymerized, styrene, acrylonitrile, methacrylonitrile, ethylene, and vinyl acetate are preferred, and acrylonitrile, methacrylonitrile, and ethylene are more preferred.

The other copolymerizable monomers may be used alone or in combination of two or more. In the acrylic rubber of the present invention, the content of these other monomer units capable of copolymerization is usually 49.9% by weight or less, preferably 39.5% by weight or less, and most preferably 29.5% by weight or less.

In the acrylic rubber of the present invention, the content of the anionic emulsifier is 10 ppm by weight or more and 4,500 weight ppm or less, preferably 500 ppm by weight or more and 4,400 weight ppm or less, and more preferably 4,300 weight ppm or less. It is more preferably 4,000 ppm by weight or less. In addition, the acrylic rubber of the present invention is obtained by emulsion polymerization of the above monomers, and an emulsifier is usually used when performing the emulsion polymerization. Furthermore, in the present invention, an anionic emulsifier is used as such an emulsifier based on the following viewpoints: the viewpoint of excellent emulsification; and the ability to effectively prevent the aggregation of aggregates caused by the polymerization from adhering to the polymerization device during the emulsion polymerization (for example, (Polymerization tank) to form dirt; further, to improve the cohesiveness of the emulsified polymerization solution obtained by performing polymerization, so that the cohesive operation can be performed with a smaller amount of coacervation. Under these circumstances, the present inventors have paid attention to the anionic emulsifier remaining in the acrylic rubber and devoted themselves to the discussion, and have found the following circumstances to complete the present invention: By mixing the anionic emulsifier in the acrylic rubber The residual amount (content) in the control is 4,500 ppm by weight or less, and the rubber crosslinked product obtained by using this acrylic rubber has high tensile strength, compression resistance, and excellent water resistance. The content of the anionic emulsifier can be determined, for example, by performing GPC measurement on acrylic rubber and measuring the peak area corresponding to the molecular weight of the anionic emulsifier in a graph obtained by GPC measurement. Although the content of the anionic emulsifier may be set to 4,500 ppm by weight or less, the lower limit thereof is preferably 10 ppm by weight or more, and preferably 500 ppm by weight or more. By setting the content of the anionic emulsifier to 500 ppm by weight or more, the type of the crosslinkable group contained in the acrylic rubber can be adjusted (for example, the crosslinkable group is a halogen atom). Time) and further increase the tensile strength, so it is better.

The anionic emulsifier is not particularly limited, and examples thereof include salts of fatty acids such as myristic acid, palmitic acid, oleic acid, and linolenic acid, alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate, and laurel Higher alcohol sulfates such as sodium sulfate, higher phosphate salts such as sodium alkyl phosphate, and alkyl sulfosuccinates. Among these anionic emulsifiers, higher phosphate salts and higher alcohol sulfate salts are preferred. These anionic emulsifiers may be used singly or in combination.

As mentioned above, although the acrylic rubber of the present invention contains an anionic emulsifier, the content of the acrylic rubber component in the acrylic rubber of the present invention is preferably 95% by weight or more, and more preferably 97% by weight or more. It is more preferably 98% by weight or more. That is, the acrylic rubber of the present invention may be an acrylic rubber composition containing an acrylic rubber component of 95% by weight or more (preferably 97% by weight or more, more preferably 98% by weight or more).

＜ Manufacturing method of acrylic rubber ＞

The acrylic rubber of the present invention can be produced by, for example, the following production method. That is, it can be produced by a method for producing an acrylic rubber including the following steps: an emulsification polymerization step that obtains emulsification by emulsifying and polymerizing a monomer used to form acrylic rubber in the presence of an anionic emulsifier, A polymerization step; adding a coagulant to the aforementioned emulsion polymerization solution to obtain water-containing pellets; a washing step, washing the water-containing pellets; and a drying step, drying the washed water-containing pellets.

<Emulsion polymerization step>

In the manufacturing method of the present invention, the emulsification polymerization step is a step of obtaining an emulsion polymerization solution by subjecting a monomer for forming an acrylic rubber to emulsion polymerization in the presence of an anionic emulsifier.

In the emulsification polymerization step, an ordinary method may be used as a method of the emulsion polymerization. Moreover, it does not specifically limit as an anionic emulsifier, The said thing can be used without limitation. From the viewpoint of setting the residual amount of the anionic emulsifier in the obtained acrylic rubber to the above range, the amount of the anionic emulsifier is 0.1 to 2.0 with respect to 100 parts by weight of the monomer used for polymerization. It is preferably parts by weight, more preferably 0.2 to 1.9 parts by weight, more preferably 0.3 to 1.8 parts by weight, even more preferably 0.3 to 0.75 parts by weight, and particularly preferably 0.35 to 0.65 parts by weight.

In addition, in the emulsification polymerization step, as the emulsifier, in addition to the anionic emulsifier, an emulsifier other than the anionic emulsifier is preferably used in combination, such as a nonionic emulsifier and a cationic emulsifier.

The nonionic emulsifier is not particularly limited, and examples thereof include polyoxyethylene alkyl ether such as polyoxyethylene dodecyl ether, and polyoxyethylene nonylphenyl ether. polyoxyethylene alkylphenol ether such as nonylphenyl ether, polyoxyethylene alkyl ester such as polyoxyethylene stearate, polyoxyethylene sorbitan alkyl ester (Polyoxyethylene sorbitan alkyl ester), ethylene oxide-propylene oxide copolymer (ethylene oxide-propylene oxide copolymer), etc. Among these nonionic emulsifiers, polyoxyethylene polypropylene glycol, polyethylene glycol monostearate, polyoxyethylene alkyl ether, and polyoxyethylene alkyl phenol ether are preferred. . In addition, as the nonionic emulsifier, a weight average molecular weight of less than 10,000 is preferable, a weight average molecular weight of 500 to 8000 is more preferable, and a weight average molecular weight of 600 to 5,000 is more preferable. The cationic emulsifier is not particularly limited, and examples thereof include alkyltrimethylammonium chloride, dialkylammonium chloride, and benzylammonium chloride. Emulsifiers other than these anionic emulsifiers may be used alone or in combination of two or more.

Among these emulsifiers other than the anionic emulsifier, a nonionic emulsifier is preferably used. That is, in the emulsification polymerization step, it is preferable to use an anionic emulsifier and a nonionic emulsifier in combination, and thereby the emulsification effect can be further enhanced and the emulsification can be performed more favorably. Even when the use amount of the anionic emulsifier is set to the above range, it is possible to more appropriately prevent a polymer or the like from adhering to a polymerization device (for example, a polymerization tank) during the emulsion polymerization to form a dirt. Therefore, the amount of the anionic emulsifier contained in the obtained acrylic rubber can be reduced more moderately.

When an anionic emulsifier and a nonionic emulsifier are used in combination, the amount of the nonionic emulsifier is more than 0 parts by weight and 4 parts by weight relative to 100 parts by weight of the monomer used for polymerization. It is preferably at most parts by weight, more preferably 0.1 to 3 parts by weight, more preferably 0.5 to 2 parts by weight, and particularly preferably 0.7 to 1.7 parts by weight. In addition, in the case where an anionic emulsifier and a nonionic emulsifier are used in combination, if the weight ratio of the anionic emulsifier / nonionic emulsifier is used, the use ratio of the two is 1 / 99 to 99/1 is preferable, 20/80 to 90/10 is preferable, 25/75 to 75/25 is more preferable, 50/50 to 75/25 is more preferable, and 65/35 is particularly preferable. ~ 75/25 is better.

In addition, in the emulsification polymerization step, in addition to using an emulsifier containing an anionic emulsifier when performing the emulsion polymerization, a polymerization initiator, a polymerization terminator, and the like may be used in accordance with a conventional method.

As the polymerization initiator, azo compounds such as azobisisobutyronitrile can be used; organic peroxides such as dicumyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, and benzoyl peroxide. Substances; inorganic peroxides such as sodium persulfate, potassium persulfate, hydrogen peroxide, ammonium persulfate; etc. These polymerization initiators can be used individually or in combination of two or more kinds. The amount of the polymerization initiator used is preferably 0.001 to 1.0 part by weight with respect to 100 parts by weight of the monomer used for the polymerization.

In addition, the organic peroxide and the inorganic peroxide as the polymerization initiator are preferably used as a redox polymerization initiator in combination with a reducing agent. The reducing agent used in combination therewith is not particularly limited, and examples thereof include compounds containing reduced metal ions such as ferrous sulfate, sodium hexamethylenediamine tetraacetate, and copper (II) naphthenate; ascorbic acid and ascorbic acid Ascorbic acid (salt) such as sodium, potassium ascorbate; erythorbic acid (salt) such as erythorbic acid, sodium erythorbic acid, potassium erythorbic acid; saccharides; sodium sulfinate such as sodium hydroxymethanesulfinate; sodium sulfite, potassium sulfite, and sulfurous acid Sodium bisulfite, aldehyde-sodium bisulfite adduct, sulfite of potassium bisulfite; coke such as sodium metabisulfite, potassium metabisulfite, sodium metabisulfite, potassium metabisulfite Sulfites; thiosulfates such as sodium thiosulfate and potassium thiosulfate; phosphorous acid (salt) of phosphorous acid, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite; pyrophosphorous acid, Pyrophosphite (salts) such as sodium pyrophosphite, potassium pyrophosphite, sodium pyrobiphosphite, and potassium pyrophosphite; sodium formaldehyde sulfoxylate and the like. These reducing agents may be used singly or in combination of two or more kinds. The amount of the reducing agent to be used is preferably 0.0003 to 0.5 parts by weight based on 100 parts by weight of the monomers used in the polymerization.

Examples of the polymerization terminator include osmium, osmium sulfate, diethylamidine, bis (hydroxylamine) sulfonate and alkali metal salts thereof, sodium dimethyldithioamine formate, and hydroquinone. Although the amount of the polymerization terminator used is not particularly limited, it is preferably 0.1 to 2 parts by weight based on 100 parts by weight of the monomer used for polymerization.

The amount of water used is preferably 80 to 500 parts by weight, and more preferably 100 to 300 parts by weight, with respect to 100 parts by weight of the monomer used for polymerization.

When carrying out the emulsion polymerization, a polymerization aid such as a molecular weight adjuster, a particle size adjuster, a chelating agent, and an oxygen trapping agent can be used as required.

Although the emulsion polymerization can be carried out by any method of batch type, semi-batch type, and continuous type, the semi-batch type is preferred. Specifically, the method is as follows: within the time range from the start of the polymerization reaction to an arbitrary time, the monomers used in the polymerization are continuously dropped into the reaction system and the emulsion polymerization reaction is simultaneously performed, etc., the reaction system is Contains a polymerization initiator and a reducing agent. Among them, at least one of a monomer, a polymerization initiator, and a reducing agent used for polymerization is continuously dropped into the polymerization reaction system and the polymerization reaction is simultaneously performed within a time range from the start of the polymerization reaction to an arbitrary time. It is preferable that all the monomers, polymerization initiator, and reducing agent used for polymerization are continuously dropped into the polymerization reaction system and the polymerization reaction is performed simultaneously within the time range from the start of the polymerization reaction to an arbitrary time. The continuous dropwise addition and simultaneous polymerization reaction can stably perform emulsion polymerization, thereby increasing the polymerization reaction rate. In addition, the polymerization is usually performed at a temperature range of 0 to 70 ° C, and preferably at a temperature range of 5 to 50 ° C.

In addition, in the case where a monomer used for polymerization is continuously dropped and a polymerization reaction is performed simultaneously, a monomer is emulsified by mixing a monomer used for polymerization with an emulsifier containing an anionic emulsifier and water to form a monomer. It is preferable that the liquid is continuously dropped in the state of the monomer emulsion. The method for preparing the monomer emulsion is not particularly limited, and examples thereof include the total amount of monomers used for polymerization using a homomixer, a disc turbine, or the like, the total amount of an emulsifier including an anionic emulsifier, And how to stir water. With respect to 100 parts by weight of the monomer used for polymerization, the amount of water used in the monomer emulsion is preferably 10 to 70 parts by weight, and more preferably 20 to 50 parts by weight.

In addition, when all the monomers, polymerization initiators, and reducing agents used in the polymerization are continuously dropped into the polymerization reaction system and the polymerization reaction is performed within a time range from the start of the polymerization reaction to an arbitrary time, it can be used An individual dropping device drops these into the polymerization system, or at least a polymerization initiator and a reducing agent can be mixed in advance, and the state of an aqueous solution can be prepared as required, and the same drops can be obtained from the state of the aqueous solution. The drip device is dropped into the polymerization system. It is also possible to continue the reaction for an arbitrary time after the completion of the dropping to further increase the polymerization reaction rate.

＜ Coagulation step ＞

In the above-mentioned manufacturing method, the aggregation step is a step of adding a coagulant to the obtained emulsion polymerization solution after performing the above-mentioned emulsion polymerization step, thereby obtaining water-containing pellets.

The coagulant is not particularly limited, and examples thereof include metal salts having 1 to 3 valences. The metal salts of 1 to 3 valence include metal salts that become metal ions of 1 to 3 valence when dissolved in water, and are not particularly limited. Examples thereof include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, and acetic acid. Salts formed from organic acids and metals selected from sodium, potassium, lithium, magnesium, calcium, zinc, titanium, manganese, iron, cobalt, nickel, aluminum, and tin. In addition, hydroxides of these metals can also be used.

Specific examples of the 1 to 3 valence metal salts include sodium chloride, potassium chloride, lithium chloride, magnesium chloride, calcium chloride, zinc chloride, titanium chloride, manganese chloride, iron chloride, and chlorine. Cobalt, nickel chloride, aluminum chloride, tin chloride and other metal chlorides; sodium nitrate, potassium nitrate, lithium nitrate, magnesium nitrate, calcium nitrate, zinc nitrate, titanium nitrate, manganese nitrate, iron nitrate, cobalt nitrate, nitric acid Nitrates such as nickel, aluminum nitrate, tin nitrate; sodium sulfate, potassium sulfate, lithium sulfate, magnesium sulfate, calcium sulfate, zinc sulfate, titanium sulfate, manganese sulfate, iron sulfate, cobalt sulfate, nickel sulfate, aluminum sulfate, tin sulfate, etc. Sulfate; etc. Among these, calcium chloride, sodium chloride, aluminum sulfate, magnesium chloride, magnesium sulfate, zinc chloride, zinc sulfate, and sodium sulfate are preferred. Among them, monovalent or divalent metal salts are preferred, calcium chloride, sodium chloride, magnesium sulfate, and sodium sulfate are more preferred, and magnesium sulfate and sodium sulfate are more preferred. And, these may be used singly or in combination.

With respect to 100 parts by weight of the acrylic rubber component in the emulsion polymerization solution, the amount of the coagulant used is preferably 1 to 100 parts by weight, more preferably 2 to 40 parts by weight, and even more preferably 3 to 20 parts by weight. It is particularly preferably 3 to 12 parts by weight. According to the present invention, by using an anionic emulsifier as an emulsifier used in the emulsion polymerization, the acrylic rubber can be well agglomerated even when the amount of the aggregating agent used is set to be as small as described above. In addition, the amount of agglutination remaining in the obtained acrylic rubber can be appropriately reduced by this, and various characteristics can be effectively prevented from being reduced due to the aggregating agent remaining.

The aggregation temperature is not particularly limited, but is preferably 50 to 90 ° C, and more preferably 60 to 90 ° C.

In addition, when the acrylic rubber of the present invention is produced, it is preferable that a part of the admixture among the admixtures blended with the acrylic rubber is previously contained in the emulsified polymerization solution before the coagulant is added to perform the coagulation operation. Specifically, it is at least any one of an anti-aging agent, a lubricant, and an ethylene oxide-based polymer. That is, at least any one of an anti-aging agent, a slip agent, and an ethylene oxide-based polymer has been blended into the emulsion polymerization solution, and in this state, it is better to perform coagulation on the emulsion polymerization solution that has been blended with these. .

For example, the anti-aging agent is contained in the emulsion polymerization solution before the aggregation, so that the deterioration of the acrylic rubber due to heat during drying can be effectively suppressed in the drying step described later. Specifically, it can effectively suppress the decrease in the Mooney viscosity due to the deterioration caused by heating during drying, and in the case of a rubber crosslinked product, it can effectively improve the tensile strength and elongation at break under normal conditions. In addition, the anti-aging agent has been blended in the emulsified polymerization solution before coagulation, so that the anti-aging agent can be appropriately dispersed, so that it can be sufficient even in the case where the amount of the anti-aging agent is reduced. Play this added effect. Specifically, even if the blending amount of the anti-aging agent is set to 0.1 to 2 parts by weight and more preferably 0.2 to 1.2 parts by weight relative to 100 parts by weight of the acrylic rubber component in the emulsion polymerization solution. A smaller blending amount can also give full play to this addition effect. In addition, even when the anti-aging agent is contained in the emulsified polymerization solution before the aggregation, the added anti-aging agent is not substantially removed when performing subsequent operations such as aggregation, cleaning, and drying, so the addition of the anti-aging agent can be fully utilized. effect. In addition, examples of the method for making the emulsion polymerization solution contain an anti-aging agent include a method of adding the emulsion polymerization solution to the emulsion polymerization solution after the emulsion polymerization and before aggregation, or a method of adding the solution to the solution before the emulsion polymerization. method. However, if it is added to the solution before the emulsion polymerization, there is a possibility that dirt and the like may be generated in the polymerization device. Therefore, the method is preferably added to the emulsion polymerization solution after the emulsion polymerization and before the aggregation.

The anti-aging agent is not particularly limited, and examples thereof include 4-methyl-2,6-bis-tertiary butyl phenol, 2,6-bis-tertiary butyl phenol, butylhydroxymethoxybenzene, and 2,6-bis-tri phenol Butyl-α-dimethylamino p-cresol, 3- (3,5-bis-tertiary-butyl-4-hydroxyphenyl) propanoic acid octadecyl ester (octadecyl-3- (3,5-di- t-butyl-4-hydroxyphenyl) propionate), styrenated phenols, 2,2'-methylenebis (6-α-methyl-benzyl-p-cresol), 4,4'-methylenebis ( 2,6-bis-tertiary butylphenol), 2,2'-methylenebis (4-methyl-6-tertiary butylphenol), 3- (3,5-bis-tertiary butyl-4-hydroxybenzene ) Stearyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), alkylated bisphenols, butylated products of p-cresol and dicyclopentadiene ( butylated reaction product of p-cresol and dicyclopentadiene) and other phenolic anti-aging agents without sulfur atoms; 2,4-bis [(octylthio) methyl] -6-methylphenol, 2,2'-thiobis -(4-methyl-6-tertiary butyl phenol), 4,4'-thiobis- (6-tertiary butyl o-cresol), 2,6- bis tertiary butyl-4- (4, 6-bis (octylthio) -1,3,5-tri &#134116; -2-ylamino) phenol (2,6-di-t-butyl-4- (4,6-bis (octylthio) -1,3,5- triazin-2-ylamino phenol) and other thiophenol-based anti-aging agents; tris (nonylphenyl) phosphite, diphenylisodecyl phosphite, diphenylisodecyl phosphite Phosphite-based anti-aging agents such as tetraphenyl dipropylene glycol diphosphite; thioester-based anti-aging agents such as dilauryl thiodipropionate; phenyl-α-naphthylamine, phenyl-β-naphthylamine , P- (p-toluenesulfonamide) diphenylamine, 4,4 '-(α, α-dimethylbenzyl) diphenylamine, N, N-diphenyl-p-phenylenediamine, N-isopropyl-N '-Phenyl-p-phenylenediamine, butyraldehyde-aniline condensate and other amine-based anti-aging agents; 2-mercaptobenzimidazole and other imidazole-based anti-aging agents; 2,2,4-trimethyl-6-ethoxy-1, Quinoline-based anti-aging agents such as 2-dihydroquinoline; Hydroquinone-based anti-aging agents such as 2,5-di- (tertiary-pentyl) hydroquinone; etc. These anti-aging agents may be used alone or in combination of two or more.

In addition, by including a lubricant in the emulsified polymerization solution before the aggregation, the lubricant can be contained in the obtained acrylic rubber in a good dispersion state, and the adhesion of the obtained acrylic rubber can be reduced moderately. This can prevent it from adhering to the dryer during drying, and can improve the operability during drying. Even in the case of an acrylic rubber composition, its excellent roll processability can be exhibited. With respect to 100 parts by weight of the acrylic rubber component in the emulsion polymerization solution, the amount of the lubricant added is preferably 0.1 to 0.4 parts by weight, more preferably 0.15 to 0.3 parts by weight, and even more preferably 0.2 to 0.3 parts by weight. . In addition, even if the emulsified polymerization solution contains a lubricant before the aggregation, when the subsequent aggregation, cleaning, and drying operations are performed, the pre-blended lubricant is not substantially removed. In the case where a lubricant is contained, this addition effect can also be fully exerted.

The lubricant is not particularly limited, and examples thereof include phosphate esters, fatty acid esters, stearylamine, and higher fatty acids. In addition, examples of the method for making the emulsion polymerization solution contain a lubricant include a method that has been added to the emulsion polymerization solution after the emulsion polymerization and before aggregation, or a method that has been added to the solution before the emulsion polymerization operation. .

In addition, the ethylene oxide polymer has been contained in the emulsion polymerization solution before the aggregation, so that the aggregation properties of the emulsion polymerization solution can be improved, and the amount of the coagulant used in the aggregation step can be reduced. Reducing the residual amount in the finally obtained acrylic rubber can effectively prevent various characteristics from being reduced due to the residue of the coagulant. The ethylene oxide polymer is not particularly limited as long as it is a polymer having a polyoxyethylene structure as a main chain structure, and examples thereof include polyoxyethylene, polyoxypropylene, and an ethylene oxide-propylene oxide copolymer. oxide-propylene oxide copolymer). Among them, polyoxyethylene is preferred. With respect to 100 parts by weight of the acrylic rubber component in the emulsion polymerization solution, the blending amount of the ethylene oxide polymer is preferably 0.01 to 1 part by weight, more preferably 0.01 to 0.6 part by weight, and 0.02 to 0.5 part by weight. Serve is better. The weight average molecular weight of the ethylene oxide-based polymer is preferably 10,000 to 1 million, more preferably 10,000 to 200,000, and even more preferably 20,000 to 120,000. Examples of the method for making the emulsion polymerization solution contain an ethylene oxide polymer include a method of adding the emulsion polymerization solution to the emulsion polymerization solution before the aggregation, or a method of adding the solution to the solution before the emulsion polymerization. Methods.

In addition, in a case where an anti-aging agent, a slip agent, and an ethylene oxide-based polymer have been previously contained in the emulsified polymerization solution before coagulation, the order of addition is not particularly limited and can be selected appropriately.

Furthermore, even when the anti-aging agent, lubricant, and / or ethylene oxide polymer are contained in the emulsion polymerization solution before the aggregation, the aggregation agent can be added to the emulsion polymerization under the same conditions as described above. The coagulation operation is performed in a liquid to obtain water-containing pellets.

＜ Cleaning steps ＞

In the above manufacturing method, the washing step is a step of washing the water-containing pellets obtained in the agglomeration step.

The method of washing is not particularly limited, and examples thereof include a method of washing with water by using water as a washing liquid and mixing the water-containing pellets with the added water. The temperature during water washing is not particularly limited, but is preferably 5 to 60 ° C, more preferably 10 to 50 ° C, and the mixing time is 1 to 60 minutes, and more preferably 2 to 30 minutes.

In addition, the amount of water added to the water-containing pellets during the water washing is not particularly limited; however, from the viewpoint of effectively reducing the residual amount of the aggregating agent in the acrylic rubber finally obtained, compared to the solid content contained in the water-containing pellets (Mainly an acrylic rubber component) For 100 parts by weight, the amount of water to be washed each time is preferably 50 to 9,800 parts by weight, and more preferably 300 to 1,800 parts by weight.

The number of times of washing with water is not particularly limited, and may be once; however, from the viewpoint of reducing the residual amount of the anionic emulsifier in the acrylic rubber finally obtained, it is preferably 2 to 10 times, and 3 to 8 times. Is better. In addition, from the viewpoint of reducing the residual amount of the anionic emulsifier in the finally obtained acrylic rubber, the number of times of washing with water is better; however, if the number of washings exceeds the above range, not only the removal of the anionic emulsifier is removed. Since the effect is small and the number of steps is increased, the productivity is greatly reduced. Therefore, the number of times of washing with water is preferably set to the above range.

In addition, in the above-mentioned manufacturing method, after washing with water, an acid may be used as a cleaning solution for acid washing. By performing acid cleaning, it can further improve its compression set resistance when used as a rubber crosslinked product, especially in the case that acrylic rubber is a carboxyl-containing acrylic rubber having a carboxyl group, and by this acid cleaning, its compression set resistance is improved. The deformability effect is particularly noticeable. The acid used for the acid cleaning is not particularly limited, and sulfuric acid, hydrochloric acid, phosphoric acid, and the like can be used without limitation. In addition, in the acid cleaning, when adding acid to the water-containing pellets, it is better to add it in an aqueous solution, and it is better to add it in an aqueous solution having a pH as follows: pH = 6 or less Preferably, pH = 4 or lower is more preferred, and pH = 3 or lower is more preferred. Moreover, the method of performing acid cleaning is not specifically limited, For example, the method of mixing the water-containing pellet with the aqueous solution of the acid added is mentioned.

In addition, the temperature when performing acid cleaning is not particularly limited, but it is preferably 5 to 60 ° C, more preferably 10 to 50 ° C, and the mixing time is 1 to 60 minutes, and more preferably 2 to 30 minutes. . The pH value of the acid-washing cleaning solution is not particularly limited, and is preferably pH = 6 or less, more preferably pH = 4 or less, and more preferably pH = 3 or less. In addition, for example, the pH value of the cleaning solution for acid cleaning can be obtained by measuring the pH value of water contained in the water-containing pellets after the acid cleaning.

After the acid cleaning, it is better to perform water washing again. As for the conditions for water washing, the above conditions may be compared.

＜ Drying step ＞

In the above manufacturing method, the drying step is a step of drying the washed water-containing pellets after performing the above-mentioned cleaning step.

The drying method for performing the drying step is not particularly limited, and examples thereof include a method using a screw-type extruder, a kneading-type dryer, an expander dryer, a hot-air dryer, and a reduced-pressure dryer for drying. Further, a method of combining these and drying may be used. Furthermore, a sieve such as a rotary sieve, a vibrating sieve, a centrifugal dehydrator, or the like may be used to filter the water-containing pellets before performing the drying step, as required.

For example, when the drying step is performed, the drying temperature is not particularly limited, and it depends on the dryer used for the drying. For example, when a hot air dryer is used, the drying temperature is preferably set to 80 to 200 ° C, and more preferably 100 to 170 ° C.

According to the manufacturing method described above, the acrylic rubber of the present invention can be obtained as described above.

The acrylic rubber of the present invention thus produced has a Mooney viscosity (ML1 + 4, 100 ° C) (Polymer Mooney) of preferably 10 to 80, more preferably 20 to 70, and even more preferably 25 to 60. .

Further, in the acrylic rubber of the present invention, the residual amount of the coagulant is preferably 9,000 ppm by weight or less, more preferably 7,000 ppm by weight or less, more preferably 5,000 ppm by weight or less, and particularly 3,500 ppm or less good. The lower limit of the residual amount of the coagulant is not particularly limited, but is preferably 10 ppm by weight or more. By setting the remaining amount of the aggregating agent to the above range, it is possible to make it more excellent in water resistance in the case of being a rubber crosslinked product. In addition, for example, the acrylic rubber can be subjected to elemental analysis to measure the content of elements contained in the flocculant, thereby determining the residual amount of the flocculant. In addition, the method of setting the remaining amount of the aggregating agent to the above amount is not particularly limited, and examples thereof include a method of setting the amount of the aggregating agent to the above range, or a method of adjusting water washing conditions as described above.

Furthermore, in the acrylic rubber of the present invention, the residual amount of the nonionic emulsifier is preferably 20,000 ppm by weight or less, more preferably 18,000 ppm by weight or less, even more preferably 15,000 ppm by weight or less, particularly 13,000 ppm by weight is preferred. The lower limit of the residual amount of the nonionic emulsifier is not particularly limited, but it is preferably 10 ppm by weight or more. By setting the residual amount of the nonionic emulsifier to the above range, the effect of the present invention can be further improved, and especially its tensile strength, compression set resistance, and water resistance can be further improved. In addition, for example, the residual amount of the nonionic emulsifier can be determined by the following method: GPC measurement of acrylic rubber, and the peak area corresponding to the molecular weight of the nonionic emulsifier in the graph obtained from the GPC measurement. The remaining amount was determined.

In the acrylic rubber of the present invention, the residual amount of the lubricant is preferably 0.1 to 0.4% by weight, more preferably 0.15 to 0.3% by weight, and even more preferably 0.2 to 0.3% by weight. By setting the residual amount of the lubricant in the above range, the occurrence of bleeding can be suppressed and the handleability and roll processability can be more effectively improved when the acrylic rubber is dried. In addition, the residual amount of the lubricant can be determined by dissolving acrylic rubber in tetrahydrofuran, and performing GPC measurement using tetrahydrofuran as a developing solvent, thereby determining the residual amount. Specifically, the integral value corresponding to the peak value of the molecular weight of the lubricant can be obtained from the measured graph, and the integral value can be compared with the integral value of the peak value of the acrylic rubber. The weight ratio of the molecular weight was determined, and then the content of the lubricant was determined.

In the acrylic rubber of the present invention, the residual amount of the anti-aging agent is preferably 500 ppm by weight or more, more preferably 1,000 ppm by weight or more, and even more preferably 2,000 ppm by weight or more. The upper limit of the content of the anti-aging agent is not particularly limited, but it is preferably 12,000 ppm by weight or less. By setting the residual amount of the anti-aging agent to the above range, it is possible to prevent the deterioration of the anti-aging agent more appropriately due to drying, thereby further improving the tensile strength of the obtained rubber crosslinked product. In addition, for example, the residual amount of the anti-aging agent can be determined by the following method: GPC measurement of acrylic rubber, and the peak area corresponding to the molecular weight of the anti-aging agent in the graph obtained from the measurement.

＜ Acrylic rubber composition ＞

The acrylic rubber composition of the present invention is obtained by blending a crosslinking agent with the acrylic rubber of the present invention.

The cross-linking agent is not particularly limited, and examples thereof include polyvalent amine compounds such as diamine compounds and their carbonates; sulfur; sulfur donors; tri &#134116; thiol compounds; polyvalent epoxy compounds; organic Ammonium carboxylic acid salts; organic peroxides; metal salts of dithiamine formic acid; polycarboxylic acids; quaternary onium salts; imidazole compounds; isocyanuric compounds; organic peroxides; and other conventionally known crosslinking agents . These crosslinking agents may be used singly or in combination of two or more kinds. The crosslinking agent is preferably selected in consideration of the type of the crosslinkable monomer unit.

Among these, in the case where the acrylic rubber of the present invention has an α, β-ethylene unsaturated carboxylic monomer unit as a crosslinkable monomer unit, the crosslinking agent is a polyvalent amine compound and Carbonate is preferred. In addition, in the case where the acrylic rubber of the present invention has a monomer unit having a halogen atom as a crosslinkable monomer unit, the crosslinking agent is made of sulfur, a sulfur donor, or a trithiol compound as good.

The polyvalent amine compound and its carbonate are not particularly limited, but a polyvalent amine compound having 4 to 30 carbon atoms and its carbonate are preferred. Examples of such a polyvalent amine compound and its carbonate include an aliphatic polyvalent amine compound and its carbonate, and an aromatic polyvalent amine compound.

The aliphatic polyvalent amine compound and its carbonate are not particularly limited, and examples thereof include hexamethylenediamine, hexamethylenediamine carbamate, and N, N'-diamethylene Phenyl-1,6-hexanediamine (N, N'-dicinnamylidene-1,6-hexanediamine), etc. Among these, hexamethylene diamine carbamate is preferred.

The aromatic polyvalent amine compound is not particularly limited, and examples thereof include 4,4'-methylenediphenylamine, p-phenylenediamine, m-phenylenediamine, and 4,4'-diaminodiphenyl ether. , 3,4'-diaminodiphenyl ether, 4,4 '-(m-phenylene diisopropylidene) diphenylamine, 4,4'-(p-phenylene diisopropylidene) di Aniline, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-diaminobenzylamine benzene, 4,4'-bis (4-amino (Phenoxy) biphenyl, m-xylylenediamine, p-xylenediamine, and 1,3,5-phenyltriamine. Among these, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane is preferred.

The sulfur donor is not particularly limited, and examples thereof include dipentamethylene thiuram hexasulfide, triethyl thiuram disulfide, and the like.

The tri &#134116; thiol compound is not particularly limited, and examples thereof include: 1,3,5-tri &#134116; -2,4,6-trithiol (1,3,5-triazine-2, 4,6-trithiol), 6-anilino-1,3,5-tri &#134116; -2,4-dithiophenol (6-anilino-1,3,5-triazine-2,4-dithiol) , 6-dibutylamine-1,3,5-tri &#134116; -2,4-dithiol (6-dibutylamino-1,3,5-triazine-2,4-dithiol), 6-diene Propylamine-1,3,5-tri &#134116; -2,4-dithiol (6-diallylamino-1,3,5-triazine-2,4-dithiol), and 6-octylamine-1 3,5-tri &#134116; -2,4-dithiol (6-octylamino-1,3,5-triazine-2,4-dithiol) and the like. Among these, 1,3,5-tri &#134116; -2,4,6-trithiol is preferred.

In the acrylic rubber composition of the present invention, the content of the crosslinking agent is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and 0.2 to 100 parts by weight of the acrylic rubber. 4 parts by weight is more preferred. By setting the content of the crosslinking agent to the above range, the rubber elasticity can be made sufficient and the mechanical strength as a rubber crosslinked product can be made excellent.

The acrylic rubber composition of the present invention preferably further contains a crosslinking accelerator. The crosslinking accelerator is not particularly limited. In the case where the acrylic rubber of the present invention has a carboxyl group as a crosslinkable group and the crosslinking agent is a polyvalent amine compound or a carbonate thereof, a guanidine compound, Diazabicyclic olefins, imidazole compounds, quaternary onium salts, tertiary phosphine compounds, aliphatic monovalent secondary amine compounds, and aliphatic monovalent tertiary amine compounds. Among these, guanidine compounds, diazabicyclic olefins, and aliphatic monovalent secondary amine compounds are preferable, and guanidine compounds are more preferable. These basic crosslinking accelerators may be used singly or in combination of two or more kinds.

Specific examples of the guanidine-based compound include 1,3-di-o-tolylguanidine, 1,3-diphenylguanidine, and the like. Specific examples of the diazabicyclic olefin include 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3.0] non-5-ene, and the like. Specific examples of the imidazole-based compound include 2-methylimidazole and 2-phenylimidazole. Specific examples of the quaternary onium salt include tetra-n-butylammonium bromide, octadecyltri-n-butylammonium bromide, and the like. Specific examples of the tertiary phosphine compound include triphenylphosphine, tri-p-toluylphosphine, and the like.

An aliphatic monovalent secondary amine compound is a compound obtained by replacing two hydrogen atoms of ammonia with an aliphatic hydrocarbon group. The aliphatic hydrocarbon group substituted for a hydrogen atom is preferably one having 1 to 30 carbon atoms. Specific examples of the aliphatic monovalent secondary amine compounds include dimethylamine, diethylamine, dipropylamine, diallylamine, diisopropylamine, di-n-butylamine, bis-tertiary butylamine, and bis-dibutylamine Diamine (di-sec-butylamine), dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, diundecylamine, didodecylamine, ditridecylamine, double fourteen Amine, dipentadecylamine, dihexadecylamine, di-2-ethylhexylamine, and dioctadecylamine.

Aliphatic monovalent tertiary amine compounds are compounds in which all three hydrogen atoms on ammonia are replaced by aliphatic hydrocarbon groups. The aliphatic hydrocarbon group substituted for a hydrogen atom is preferably one having 1 to 30 carbon atoms. Specific examples of the aliphatic monovalent tertiary amine compound include trimethylamine, triethylamine, tripropylamine, triallylamine, triisopropylamine, tri-n-butylamine, tris (tertiary butyl) amine, and tris (di) Butyl) amine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, tri (undecyl) amine, and tris (dodecyl) amine.

Furthermore, in the case where the acrylic rubber of the present invention has a halogen atom as a crosslinkable group and the crosslinking agent is sulfur or a sulfur donor, fatty acid metal soaps such as sodium stearate and potassium stearate (fatty) can be used. acid metallic soap) and the like as a crosslinking accelerator. Alternatively, in the case where the acrylic rubber system of the present invention has a halogen atom as a crosslinkable group and the crosslinking agent is a thiol compound, dithiocarbamate and its derivative, sulfur Urea compounds, and thiuram sulfide compounds are used as crosslinking accelerators. Among them, from the viewpoint of the tensile strength of the obtained rubber cross-linked product, the crosslinking agent is preferably sulfur or sulfur preform, and from the viewpoint of compression compression set resistance and water resistance, it is based on three &#134116; Thiol compounds are preferred.

In the acrylic rubber composition of the present invention, the content of the crosslinking accelerator is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 7.5 parts by weight, and 1 to 100 parts by weight of the acrylic rubber. 5 parts by weight is more preferred. By setting the content of the cross-linking accelerator to the above range, the tensile strength and compression set resistance of the obtained rubber cross-linked product can be further improved.

Further, in addition to the above components, a blending agent generally used in the field of rubber processing may be blended in the acrylic rubber composition of the present invention. Examples of such admixtures include: reinforcing fillers such as silica and carbon black; non-reinforcing fillers such as calcium carbonate and clay; anti-aging agents; light stabilizers; coking inhibitors; plasticizers; processing aids; Adhesives; Lubricants; Lubricants; Flame retardants; Antifungal agents; Antistatic agents; Colorants; Crosslinking retarders; etc. The blending amount of these admixtures is not particularly limited as long as it does not interfere with the purpose and effect of the present invention, and the blending amount may be determined according to the blending purpose.

Furthermore, as long as the effect of the present invention is not impaired, rubbers, elastomers, resins, and the like other than the acrylic rubber of the present invention may be further blended into the acrylic rubber composition of the present invention. For example, it can be blended: acrylic rubber other than the acrylic rubber of the present invention, natural rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber Rubber other than acrylic rubber such as silicone rubber, fluororubber; olefin-based elastomer, styrene-based elastomer, vinyl chloride-based elastomer, polyester-based elastomer, polyamide-based elastomer, polyurethane-based elastomer, polymer Elastomers such as silicone elastomers; polyolefin resins, polystyrene resins, polyacrylic resins, polyphenylene ether resins, polyester resins, polycarbonate resins, polyamide resins, Vinyl chloride resin, fluororesin and other resins; etc. In addition, with respect to 100 parts by weight of the acrylic rubber, the total blending amount of the rubber, elastomer, and resin other than the acrylic rubber of the present invention is preferably 50 parts by weight or less, and more preferably 10 parts by weight or less. It is more preferably 1 part by weight or less.

The acrylic rubber composition of the present invention is prepared by the following methods: a cross-linking agent and various admixtures used in accordance with demand are blended in the acrylic rubber, and a Banbury mixer and a kneading agent are used; It is mixed and kneaded by a machine, etc. Next, a kneading roller is used for kneading and the like.

The mixing order of the components is not particularly limited, and it is preferable to mix the components that are difficult to cause reaction or decomposition under heat, and then it will be easy to use a temperature that does not cause reaction or decomposition. The cross-linking agent or the like that generates a reaction or decomposes under heat is mixed, and the mixing is performed for a short period of time.

＜ Rubber crosslinked products ＞

The rubber crosslinked product of the present invention is obtained by crosslinking the acrylic rubber composition of the present invention.

The rubber crosslinked product of the present invention can be produced by using the acrylic rubber composition of the present invention and a molding machine corresponding to a desired shape, such as an extruder, an injection molding machine, a compressor, and a roll Molding and the like are performed, a crosslinking reaction is performed by heating, and the shape is fixed to be a rubber crosslinked product. In this case, the cross-linking may be performed after forming in advance, or the forming and cross-linking may be performed simultaneously. The molding temperature is usually 10 to 200 ° C, preferably 25 to 120 ° C. The crosslinking temperature is usually 130 to 220 ° C, preferably 150 to 190 ° C, and the crosslinking time is usually 2 minutes to 10 hours, and preferably 3 minutes to 5 hours. As for the heating method, the method used when the rubber is crosslinked may be selected, such as pressure heating, steam heating, oven heating, and hot air heating.

In addition, the rubber cross-linked product of the present invention may be further heated for secondary cross-linking in accordance with the shape, size, and the like of the rubber cross-linked product. Although the secondary crosslinking varies depending on the heating method, the crosslinking temperature, the shape, etc., it is preferably carried out for 1 to 48 hours. You can choose the heating method and heating temperature.

Moreover, the rubber crosslinked product of the present invention thus obtained is suitable for use as a sealing material such as O-rings, packaging, oil seals, and bearing seals in a wide range of fields such as transportation machinery such as automobiles, general machinery, and electrical equipment; Gaskets; buffer materials, shock-proof materials; wire covering materials; industrial tapes; pipes and hoses; sheets; etc.

Examples are described below.

Hereinafter, the present invention will be specifically described with examples and comparative examples. In addition, the "part" in each case is a weight basis as long as it is not specifically limited.

Various physical properties are evaluated in accordance with the following methods.

[Muni viscosity (ML1 + 4, 100 ° C)]

The Mooney viscosity (polymer Mooney) of acrylic rubber is measured in accordance with JIS K6300.

[Residual amount of anionic emulsifier and nonionic emulsifier]

Acrylic rubber was dissolved in tetrahydrofuran, and GPC measurement was performed using tetrahydrofuran as a developing solvent to measure the residual amount of anionic emulsifier and nonionic emulsifier in acrylic rubber. Specifically, the integral value corresponding to the peak value of the molecular weight of the anionic emulsifier and nonionic emulsifier used in the production can be obtained from the measured graph, and the integral value and the The integrated values of the peaks are compared, and the weight ratio is calculated from the molecular weight corresponding to these integrated values, and the residual amounts of the anionic emulsifier and the nonionic emulsifier are calculated.

[Residual amount of coagulant]

ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometer) was used for elemental analysis of acrylic rubber, and the residual amount of coagulant in acrylic rubber was measured. Specifically, the content ratio of the elements in the aggregating agent used was determined by elemental analysis, and the remaining amount of the aggregating agent was calculated from the obtained content ratio.

[Residual amount of lubricant and anti-aging agent]

Acrylic rubber was dissolved in tetrahydrofuran, and GPC measurement was performed using tetrahydrofuran as a developing solvent to measure the residual amount of the slip agent and anti-aging agent in acrylic rubber. Specifically, the integral value corresponding to the peak value of the molecular weight of the lubricant and the anti-aging agent used in the manufacture can be obtained from the measured graph, and the integral value of these integral values and the peak value of the acrylic rubber can be calculated. The comparison is performed, and the residual amounts of the weight ratio lubricant and the anti-aging agent are obtained from the molecular weights corresponding to these integrated values.

[Tensile strength and elongation]

The acrylic rubber composition was put into a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm. The cross-linking was performed once by pressing at a pressure of 10 MPa and a temperature of 170 ° C. for 20 minutes. Next, the obtained primary cross-linked product was heated at 170 ° C. for 4 hours to perform secondary cross-linking in a gear oven, thereby obtaining a sheet-like rubber cross-linked product. The obtained rubber cross-linked product was punched with a No. 3 dumbbell to prepare a test piece. Next, use this test piece and measure its tensile strength and elongation under normal conditions in accordance with JIS K 6251.

[Compression resistance to permanent deformation]

The acrylic rubber composition was pressurized at 170 ° C for 20 minutes using a mold, thereby subjecting it to primary cross-linking to obtain a cylindrical primary cross-linked product having a diameter of 29 mm and a height of 12.7 mm. Next, the obtained primary crosslinked product was further heated at 170 ° C. for 4 hours using a gear oven to perform secondary crosslinking, thereby obtaining a cylindrical rubber crosslinked product. Next, using the obtained rubber crosslinked product and in accordance with JIS K 6262, the rubber crosslinked product was placed in a state of being compressed by 25% under an environment of 175 ° C for 70 hours. Then, the compression-resistant permanent deformation rate was measured. The smaller this value, the better the compression set resistance.

[Water resistance]

The acrylic rubber composition was put into a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm. The cross-linking was performed once by pressing at a pressure of 10 MPa and a temperature of 170 ° C. for 20 minutes. Next, the obtained primary crosslinked product was further heated in a gear oven at 170 ° C. for 4 hours to perform secondary crosslinking, thereby obtaining a sheet-like rubber crosslinked product. Next, a 3 cm × 2 cm × 0.2 cm test piece was cut out of the obtained sheet-shaped rubber cross-linked product, and the obtained test piece was immersed in distilled water whose temperature was adjusted to 80 ° C. for 70 hours in accordance with JIS K6258. In order to carry out the immersion test. The volume change rate of the test piece before and after immersion was measured according to the following formula. The smaller the volume change rate before and after immersion, it can be judged that the swelling of water is suppressed and the water resistance is superior. Volume change rate before and after immersion (%) = (volume of test piece after immersion-volume of test piece before immersion) ÷ volume of test piece before immersion × 100

[Manufacturing example 1]

46.294 parts of pure water, 49.3 parts of ethyl acrylate, 49.3 parts of n-butyl acrylate, 1.4 parts of n-butyl fumarate, and sodium lauryl sulfate (brand name "EMAL 2FG") as an anionic emulsifier, Kao Corporation 0.624 parts) and 1.5 parts of polyoxyethylene lauryl ether (trade name "EMULGEN 105", weight average molecular weight: about 1500, manufactured by Kao Corporation) as a nonionic surfactant, and filled in a mixer equipped with a homomixer The mixture was stirred in a container to obtain a monomer emulsion.

Next, 170.853 parts of pure water and 2.97 parts of the monomer emulsion obtained above were put into a polymerization reaction tank equipped with a thermometer and a stirring device, and the temperature was cooled to 12 ° C. under a nitrogen stream. Then, 145.44 parts of the monomer emulsion obtained above, 0.00033 parts of ferrous sulfate as a reducing agent, 0.264 parts of sodium ascorbate as a reducing agent, and 7.72 parts of a 2.85% by weight potassium persulfate aqueous solution as a polymerization initiator ( The amount of potassium persulfate was 0.22 parts) continuously dropped into the polymerization reaction tank for 3 hours. Thereafter, the temperature in the polymerization reaction tank was maintained at 23 ° C. and the reaction was continued for 1 hour. It was confirmed that the polymerization conversion rate was 95%, and hydroquinone was added as a polymerization terminator to stop the polymerization reaction to obtain an emulsion polymerization solution.

Next, 100 parts of the emulsion polymerization solution obtained by polymerization was mixed with the following components to obtain a mixed solution: 3- (3,5-bis-tertiary-butyl-4-hydroxyphenyl) propane as an anti-aging agent. Octadecyl acid (trade name "Irganox 1076", manufactured by BASF Corporation) 0.3 parts (total of monomers used in the preparation of the emulsion polymerization solution (ie, ethyl acrylate, n-butyl acrylate, transbutyl) Total of mono-n-butyl phthalate) 1 part for 100 parts), 0.011 part of polyoxyethylene (weight average molecular weight (Mw) = 100,000) (relative to the monomers used in the production of the emulsion polymerization solution) 0.036 parts for a total of 100 parts), and polyoxyethylene stearyl ether phosphate (trade name "Phosphanol RL-210") as a lubricant, weight average molecular weight: about 500, Toho Chemical Industry (Manufactured by the company) 0.075 parts (0.25 parts with respect to 100 parts in total of the monomers used for filling the emulsion polymerization liquid). The obtained mixed liquid was transferred to a coagulation tank, and 60 parts of industrial water was added to 100 parts of this mixed liquid and the temperature was raised to 85 ° C. Thereafter, while stirring the mixed solution at 85 ° C., 3.3 parts of sodium sulfate as a coagulant (11 parts relative to 100 parts of the polymer contained in the mixed solution) were continuously continuously added to aggregate the polymer, thereby Water-containing pellets of acrylic rubber (A1) were obtained.

Next, 388 parts of industrial water was added to 100 parts of the solid content of the water-containing pellets obtained above, and the mixture was stirred at room temperature for 5 minutes. After that, the water-containing pellets are washed with water by draining the water from the coagulation tank. In addition, in this manufacturing example, this water washing was repeated 4 times.

Next, an aqueous sulfuric acid solution (pH = 3) was added to 100 parts of the solid components of the water-containing pellets which had been washed with water. This sulfuric acid aqueous solution was obtained by mixing 388 parts of industrial water and 0.13 parts of concentrated sulfuric acid. Stir for 5 minutes in the coagulation tank at room temperature. Thereafter, the water-containing pellets are acid-washed by draining water from the coagulation tank. In addition, the pH value (the pH value of water in the water-containing pellets) of the water-containing pellets after acid washing was measured, and the result was pH = 3. Next, 388 parts of pure water was added to 100 parts of the solid components of the water-containing pellets that had been pickled, and the mixture was stirred at room temperature for 5 minutes. Thereafter, the water-containing pellets were purged with pure water by draining water from the coagulation tank. The hot water drier was used to dry the water-containing pellets at 110 ° C. for 1 hour, thereby obtaining a solid acrylic rubber (A1).

The obtained acrylic rubber (A1) had a Mooney viscosity (ML1 + 4, 100 ° C) of 33, and the composition of the acrylic rubber (A1) was: 49.3% by weight of ethyl acrylate units, 49.3% by weight of n-butyl acrylate units, butane Mono-n-butyl oxalate unit was 1.4% by weight. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, anti-aging agent, and lubricant in the acrylic rubber (A1) were measured according to the method described above. The results are shown in Table 1.

[Manufacture example 2]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.624 parts to 0.567 parts, and the amount of polyoxyethylene lauryl ether used as a nonionic emulsifier was changed from 1.5 parts to 1.4 parts; The external comparison was made with Production Example 1 to obtain a monomer emulsion. Next, in addition to using the obtained monomer emulsion, a solid acrylic rubber (A2) was obtained in accordance with Production Example 1 by comparison.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A2) was 34, and the composition of the acrylic rubber (A2) was: 49.3% by weight of ethyl acrylate units, 49.3% by weight of n-butyl acrylate units, and Mono-n-butyl oxalate unit was 1.4% by weight. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, anti-aging agent, and lubricant in the acrylic rubber (A2) were measured according to the method described above. The results are shown in Table 1.

[Manufacture example 3]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.624 parts to 0.283 parts, the amount of polyoxyethylene lauryl ether used as a nonionic emulsifier was changed from 1.5 parts to 1.4 parts, and water washes The number of times was changed from 4 times to 8 times; otherwise, a monomer emulsion was obtained in accordance with Production Example 1. Next, a solid acrylic acid rubber (A3) was obtained in the same manner as in Production Example 1 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A3) was 34, and the composition of the acrylic rubber (A3) was: 49.3% by weight of ethyl acrylate units, 49.3% by weight of n-butyl acrylate units, Mono-n-butyl oxalate unit was 1.4% by weight. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, anti-aging agent, and lubricant in the acrylic rubber (A3) were measured according to the method described above. The results are shown in Table 1.

[Manufacture example 4]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.624 to 0.709 parts, and the amount of polyoxyethylene lauryl ether used as a nonionic emulsifier was changed from 1.5 to 1.82 parts. The external comparison was made with Production Example 1 to obtain a monomer emulsion. Next, a solid acrylic acid rubber (A4) was obtained in the same manner as in Production Example 1 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A4) was 31, and the composition of the acrylic rubber (A4) was: 49.3% by weight of ethyl acrylate units, 49.3% by weight of n-butyl acrylate units, and antibutyl Mono-n-butyl oxalate unit was 1.4% by weight. Then, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, anti-aging agent, and lubricant in the acrylic rubber (A4) were measured in accordance with the above method. The results are shown in Table 1.

[Example 1]

Using a Banbury mixer, the following components were added to 100 parts of the acrylic rubber (A1) obtained in Production Example 1 and mixed at 50 ° C for 5 minutes. The components described above are clay (trade name) "Satintone 5A", 30 parts by Takehara Chemical Industry Co., Ltd., calcined kaolin, 15 parts by silica (trade name "CARPLEX 1120", manufactured by Evonik), 35 parts by silica (trade name "CARPLEX 67", manufactured by Evonik) 2 parts of stearic acid, 1 part of ester wax (trade name "Gleck G-8205", manufactured by DAINIPPON INK AND CHEMICALS), 1 part of 4, 4'-bis (α, α-dimethylbenzyl) diphenylamine (commodity Named "Nocrac CD", manufactured by Onai Shinko Chemical Industry Co., Ltd., and 3-methacryloxypropyltrimethoxysilane (trade name "KBM-503", Shin-Etsu Silicone Co., Ltd. System, silane coupling agent) 1 part. Next, the obtained mixture was transferred to a roller at 50 ° C., and 0.6 part of hexamethylenediamine carbamate (trade name “Diak # 1”, manufactured by DowDuPont, an aliphatic polyvalent amine compound) was blended. And 2,3-di-o-tolylguanidine (trade name "Nocceler DT", manufactured by Onai Shinko Chemical Co., Ltd., crosslinking accelerator), and kneaded to obtain an acrylic rubber composition.

Next, the obtained acrylic rubber composition was used to measure and evaluate tensile strength, elongation, compression set resistance, and water resistance in accordance with the methods described above. The results are shown in Table 1.

[Example 2]

The acrylic rubber (A2) obtained in Manufacturing Example 2 was used in place of the acrylic rubber (A1) obtained in Manufacturing Example 1. Otherwise, an acrylic rubber composition was obtained in accordance with Example 1, and measurement and evaluation were performed in the same manner. The results are shown in Table 1.

[Example 3]

The acrylic rubber (A3) obtained in Manufacturing Example 3 was used in place of the acrylic rubber (A1) obtained in Manufacturing Example 1. Otherwise, an acrylic rubber composition was obtained in accordance with Example 1, and similarly measured and evaluated. The results are shown in Table 1.

[Comparative Example 1]

The acrylic rubber (A4) obtained in Manufacturing Example 4 was used instead of the acrylic rubber (A1) obtained in Manufacturing Example 1. Otherwise, an acrylic rubber composition was obtained in accordance with Example 1, and the same measurement and evaluation were performed. The results are shown in Table 1.

[Table 1]

(* 1) The addition amount of the admixture used to prepare the monomer emulsion is expressed as the blending amount with respect to 100 parts of the loading monomer.

(* 2) The amount of the admixture to be added to the emulsified polymerization solution before coagulation is expressed as a blended amount of 100 parts with respect to the emulsified polymerization solution.

(* 3) The addition amount of the coagulant used in the coagulation step is expressed as the blending amount with respect to 100 parts of the mixed liquid, which is an anti-aging agent, polyoxyethylene, and a slip agent. It is obtained by emulsifying the polymerization solution.

[Evaluation of Examples 1 to 3 and Comparative Example 1]

As shown in Table 1, a rubber crosslinked product obtained by using an acrylic rubber having a residual amount (content) of at least 10 ppm by weight and not more than 4,500 ppm by weight has high tensile strength and resistance to compression and permanent Both deformability and water resistance are excellent (Examples 1 to 3).

On the other hand, a rubber crosslinked product obtained using an acrylic rubber having a residual amount (content) of more than 4,500 ppm by weight has poor water resistance (Comparative Example 1).

[Manufacturing example 5]

46.294 parts of pure water, 50 parts of ethyl acrylate, 35 parts of n-butyl acrylate, 12.9 parts of 2-methoxyethyl acrylate, 2.1 parts of vinyl chloroacetate, and sodium lauryl sulfate (brand name "EMAL" 2FG ", manufactured by Kao Corporation), 0.421 parts, and 1.4 parts of polyoxyethylene dodecyl ether (trade name" EMULGEN 非 105 ", weight average molecular weight: about 1500, manufactured by Kao Corporation) as a nonionic surfactant A monomer emulsion is obtained by stirring in the mixing container of a homomixer.

Next, 170.853 parts of pure water and 2.96 parts of the monomer emulsion obtained above were put into a polymerization reaction tank equipped with a thermometer and a stirring device, and the temperature was cooled to 12 ° C. under a nitrogen stream. Next, 145.16 parts of the monomer emulsion obtained above, 0.00033 parts of ferrous sulfate as a reducing agent, 0.264 parts of sodium ascorbate as a reducing agent, and 2.85% by weight potassium persulfate aqueous solution 7.72 as a polymerization initiator. Parts (the amount of potassium persulfate was 0.22 parts) were continuously dropped into the polymerization reaction tank and performed for 3 hours. Thereafter, the temperature in the polymerization reaction tank was maintained at 23 ° C. and the reaction was continued for 1 hour. It was confirmed that the polymerization conversion rate was 95%, and hydroquinone was added as a polymerization terminator to stop the polymerization reaction to obtain an emulsion polymerization solution.

Next, 100 parts of the emulsion polymerization solution obtained by the polymerization are mixed with the following components to obtain a mixed solution, wherein each component is 3- (3,5-bis-tertiary-butyl- 4-Hydroxyphenyl) octadecyl propionate (trade name "Irganox 1076", manufactured by BASF Corporation) 0.3 parts (total of monomers used in the preparation of the emulsion polymerization solution (ie, ethyl acrylate, acrylic acid N-butyl ester, 2-methoxyethyl acrylate, and vinyl chloroacetate (total 100 parts); and polyoxyethylene (weight average molecular weight (Mw) = 100,000) 0.011 (for manufacturing emulsion polymerization) For a total of 100 parts of the monomer used in the liquid filling, 0.036 parts). The obtained mixed liquid was transferred to a coagulation tank, and 60 parts of industrial water was added to 100 parts of this mixed liquid and the temperature was raised to 85 ° C. Thereafter, while stirring the mixed solution at 85 ° C., 3.3 parts of sodium sulfate as a coagulant (11 parts relative to 100 parts of the polymer contained in the mixed solution) were continuously continuously added to aggregate the polymer, thereby Water-containing pellets of acrylic rubber (A5) were obtained.

Next, 388 parts of industrial water was added to 100 parts of the solid content of the water-containing pellets obtained above, and after stirring at room temperature for 5 minutes in the coalescence tank, the water was discharged from the coalescence tank, thereby washing the water-containing pellets with water. In addition, in this manufacturing example, this water washing was repeated 4 times. Next, the washed water-containing pellets were dried at 110 ° C. for 1 hour using a hot-air dryer, thereby obtaining a solid acrylic rubber (A5).

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A5) was 38, and the composition of the acrylic rubber (A5) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. Then, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A5) were measured in accordance with the above method. The results are shown in Table 2-2.

[Manufacturing example 6]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.567 parts; otherwise, a monomer emulsion was obtained in accordance with Production Example 5. Next, a solid acrylic acid rubber (A6) was obtained in the same manner as in Production Example 5 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A6) was 38, and the composition of the acrylic rubber (A6) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A6) were measured according to the above method. The results are shown in Table 2-2.

[Manufacturing Example 7]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.283 parts, and the number of washing times was changed from 4 to 8 times; otherwise, a monomer emulsion was obtained in accordance with Manufacturing Example 5. Next, a solid acrylic acid rubber (A7) was obtained in the same manner as in Production Example 5 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A7) was 38, and the composition of the acrylic rubber (A7) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A7) were measured according to the method described above. The results are shown in Table 2-2.

[Manufacture example 8]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.661 parts; otherwise, a monomer emulsion was obtained in accordance with Production Example 5. Next, it carried out similarly to the manufacturing example 5 except using the obtained monomer emulsion, and obtained the solid acrylic rubber (A8).

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A8) was 38, and the composition of the acrylic rubber (A8) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. Then, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A8) were measured according to the method described above. The results are shown in Table 2-2.

[Manufacturing Example 9]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.704 parts; otherwise, a monomer emulsion was obtained in accordance with Production Example 5. Next, a solid acrylic acid rubber (A9) was obtained in the same manner as in Production Example 5 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A9) was 38, and the composition of the acrylic rubber (A9) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A9) were measured according to the method described above. The results are shown in Table 2-2.

[Manufacturing example 10]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.754 parts; otherwise, a monomer emulsion was obtained in accordance with Production Example 5. Next, a solid acrylic acid rubber (A10) was obtained in the same manner as in Production Example 5 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A10) was 38, and the composition of the acrylic rubber (A10) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A10) were measured according to the above method. The results are shown in Table 2-2.

[Manufacturing Example 11]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.788 parts; otherwise, a monomer emulsion was obtained in accordance with Production Example 5. Next, a solid acrylic acid rubber (A11) was obtained in the same manner as in Production Example 5 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A11) was 38, and the composition of the acrylic rubber (A11) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A11) were measured according to the method described above. The results are shown in Table 2-2.

[Manufacture example 12]

The amount of sodium lauryl sulfate used as an anionic emulsifier was changed from 0.421 parts to 0.854 parts; otherwise, a monomer emulsion was obtained in accordance with Production Example 5. Next, a solid acrylic acid rubber (A12) was obtained in the same manner as in Production Example 5 except that the obtained monomer emulsion was used.

The acrylic viscosity (ML1 + 4, 100 ° C) of the obtained acrylic rubber (A12) was 38, and the composition of the acrylic rubber (A12) was: 50% by weight of ethyl acrylate units, 35% by weight of n-butyl acrylate units, and acrylic acid 2 -12.9% by weight of methoxyethyl units and 2.1% by weight of vinyl chloroacetate units. In addition, the residual amounts of the anionic emulsifier, nonionic emulsifier, coagulant, and anti-aging agent in the acrylic rubber (A12) were measured in accordance with the method described above. The results are shown in Table 2-2.

[Example 4]

Using a Banbury mixer, the following components were added to 100 parts of the acrylic rubber (A5) obtained in Production Example 5, and mixed at 50 ° C for 5 minutes. The components described above are: FEF carbon black (Brand name "SEAST SO", manufactured by Tokai Carbon) 60 parts, 2 parts of stearic acid, ester wax (product name "Gleck G-8205", manufactured by DAINIPPON INK AND CHEMICALS) 1 part, and 4, 4'- 2 parts of bis (α, α-dimethylbenzyl) diphenylamine (trade name "Nocrac CD", manufactured by Onai Shinko Chemical Industry Co., Ltd.). Next, the obtained mixture was transferred to a roll at 50 ° C, and 0.3 parts of sulfur (trade name "SULFAX (registered trademark) PMC", manufactured by Tsurumi Chemical Industry Co., Ltd.) and sodium stearate (trade name "NS SOAP") were blended. , Made by Kao Corporation, 3 parts of cross-linking accelerator, and 0.5 parts of potassium stearate (trade name "Nonsoul (registered trademark) SK-1", made by Japan Oil & Fat Co., Ltd., cross-linking accelerator). This gives an acrylic rubber composition.

Next, the obtained acrylic rubber composition was used to measure and evaluate tensile strength, elongation, compression set resistance, and water resistance in accordance with the method described above. The results are shown in Table 2-2.

[Example 5]

The acrylic rubber (A6) obtained in Production Example 6 was used instead of the acrylic rubber (A5) obtained in Production Example 5. Except that, the acrylic rubber composition was obtained in the same manner as in Example 4, and the same amount was obtained. Testing and Evaluation. The results are shown in Table 2-2.

[Example 6]

Using a Banbury mixer, the following components were added to 100 parts of the acrylic rubber (A6) obtained in Production Example 6, and mixed at 50 ° C for 5 minutes. Each component described above: FEF carbon black (Brand name "SEAST SO", manufactured by Tokai Carbon) 60 parts, 2 parts of stearic acid, ester wax (product name "Gleck G-8205", manufactured by DAINIPPON INK AND CHEMICALS) 1 part, and 4, 4'- 2 parts of bis (α, α-dimethylbenzyl) diphenylamine (trade name "Nocrac CD", manufactured by Onai Shinko Chemical Industry Co., Ltd.). Next, the obtained mixture was transferred to a roller at 50 ° C, and 1,3,5-tri &#134116; -2,4,6-trithiol (trade name "ZISNET F", Sankyo Kasei Co., Ltd.) was blended. (Manufactured) 0.5 parts, dibutylamine zinc dithioformate (trade name "Nocceler BZ", manufactured by Onai Shinko Chemical Industry, cross-linking accelerator), 1.5 parts, diethylthiourea (trade name "Nocceler EUR", Onai Shinko 0.3 parts by cross-linking accelerator manufactured by Chemical Industry Co., Ltd. and N- (cyclohexylthio) phthalimide (trade name "RETARDER CTP, manufactured by Onai Shinko Chemical Industry Co., Ltd., anti-scorch" Agent) 0.2 parts, and kneading was performed to obtain an acrylic rubber composition.

Next, the obtained acrylic rubber composition was measured and evaluated in accordance with Example 4. The results are shown in Table 2-2.

[Example 7]

Except that the acrylic rubber (A7) obtained in Manufacturing Example 7 was used in place of the acrylic rubber (A5) obtained in Manufacturing Example 5, the acrylic rubber composition was obtained in accordance with Example 4, and measurement and evaluation were performed in the same manner. The results are shown in Table 2-2.

[Comparative Examples 2 to 6]

The acrylic rubbers (A8) to (A12) obtained in Manufacturing Examples 8 to 12 were used in place of the acrylic rubber (A5) obtained in Manufacturing Example 5, respectively; otherwise, an acrylic rubber composition was obtained in accordance with Example 4, and the same Measure and evaluate. The results are shown in Table 2-2.

[table 2-1]

[Table 2-2]

(* 4) The amount of the admixture used to prepare the monomer emulsion is expressed as the amount of the blending agent relative to 100 parts of the loading monomer.

(* 5) The amount of the admixture added to the emulsified polymerization solution before the coagulation is expressed in terms of 100 parts of the emulsified polymerization solution.

(* 6) The addition amount of the coagulant used in the coagulation step is expressed as a blending amount with respect to 100 parts of the mixed liquid, which is obtained by adding an anti-aging agent and polyoxyethylene to Obtained by emulsifying the polymerization solution.

(* 7) The blending amount of the crosslinking agent is expressed as a blending amount with respect to 100 parts of acrylic rubber.

[Evaluation of Examples 4 to 7 and Comparative Examples 2 to 6]

As shown in Table 2, the rubber crosslinked products obtained by using acrylic rubber having an anionic emulsifier with a residual amount (content) of 10 wt ppm or more and 4,500 wt ppm or less have high tensile strength and resistance to compression set and Water resistance was balanced and excellent (Examples 4 to 7). In particular, compared with Examples 4, 5, and 7 in which sulfur was used as a crosslinking agent, in the case of using a monomer unit containing a chlorine atom in an acrylic rubber system, it was confirmed that the residual amount of the anionic emulsifier was set to At least 500 ppm by weight, the elongation can be further increased. In addition, comparing Examples 4, 5, and 7 using sulfur as a cross-linking agent with Example 6 using a tri- &#134116; compound as a cross-linking agent, it was confirmed that by using sulfur as a cross-linking agent, the following can be confirmed: In order to improve the tensile strength and elongation, compression resistance can be further improved by using three compounds as cross-linking agents.

On the other hand, a crosslinked rubber obtained by using an acrylic rubber having an anionic emulsifier with a residual amount (content) exceeding 4,500 weight ppm has poor tensile strength, compression set resistance, and water resistance, especially tensile resistance. The strength decreases (Comparative Examples 2 to 6).

no

no

Claims (19)

An acrylic rubber having an anionic emulsifier content of 10 ppm by weight to 4,500 ppm by weight. The acrylic rubber according to claim 1, wherein the content of the nonionic emulsifier is 10 ppm by weight or more and 20,000 ppm by weight or less. The acrylic rubber according to claim 2, wherein the content of the nonionic emulsifier is 10 ppm by weight or more and 15,000 ppm by weight or less. The acrylic rubber according to claim 1 or 2, wherein the content of the coagulant is 10 ppm by weight or more and 9,000 ppm by weight or less. The acrylic rubber according to claim 4, wherein the content of the coagulant is 10 ppm by weight or more and 3,500 ppm by weight or less. The acrylic rubber according to claim 1 or 2, wherein the content of the slip agent is 0.1 to 0.4% by weight. The acrylic rubber according to claim 6, wherein the content of the lubricant is 0.2 to 0.3% by weight. The acrylic rubber according to claim 1 or 2, wherein the content of the anti-aging agent is 500 ppm by weight or more. The acrylic rubber according to claim 8, wherein the content of the anti-aging agent is 12,000 ppm by weight or less. The acrylic rubber according to claim 1 or 2, wherein the content of the acrylic rubber component is 95% by weight or more. The acrylic rubber according to claim 1 or 2, wherein the acrylic rubber contains a monomer unit having a halogen atom. A method for manufacturing an acrylic rubber, which is a method for manufacturing the acrylic rubber according to claim 1 or 2, and includes the following steps: an emulsification polymerization step, which is a method of forming monomers for forming the acrylic rubber in an anionic emulsifier. A step of obtaining an emulsified polymerization solution by performing emulsification polymerization in the presence; and a coagulation step, which is a step of adding a coagulant to the emulsified polymerization solution to agglomerate to obtain water-containing pellets. The method for producing an acrylic rubber according to claim 12, wherein in the emulsification polymerization step, the single system is subjected to emulsion polymerization in the presence of a nonionic emulsifier and the anionic emulsifier. The method for manufacturing an acrylic rubber according to claim 12, further comprising an adding step, wherein the emulsifying polymerization solution contains the lubricant and the anti-aging agent before the aggregation. The method for producing an acrylic rubber according to claim 12, further comprising an addition step of adding the lubricant and an ethylene oxide-based polymer to the emulsified polymerization solution before aggregation. The method for manufacturing an acrylic rubber according to claim 12, further comprising an addition step of adding the anti-aging agent and an ethylene oxide-based polymer to the emulsion polymerization solution before the aggregation. The method for manufacturing an acrylic rubber according to claim 12, further comprising an adding step, wherein the emulsifying polymerization solution contains the lubricant, the anti-aging agent, and an ethylene oxide polymer before the aggregation. An acrylic rubber composition comprising the acrylic rubber and a crosslinking agent according to claim 1 or 2. A rubber crosslinked product obtained by crosslinking the acrylic rubber composition according to claim 18.