JPH03160008A - Acrylic copolymer rubber and its production - Google Patents

Abstract

PURPOSE:To obtain an acrylic copolymer rubber excellent in tensile strength, heat resistance, low-temperature resistance, oil resistance, etc.,by copolymerizing a specified (meth)acrylic ester with an alkyl acrylate and a crosslinking monomer in a specified weight ratio by using a radical polymerization initiator. CONSTITUTION:5-30wt. % (meth)acrylic ester of formula I (wherein R<1> is H or a methyl group; R<2> is a 3-20 C alkylene group; R<3> is a 1-20C hydrocarbon group or the like; and l is 1-20) is mixed with 50-94.9 wt. % alkyl acrylate of formula II (wherein R<4> is a 3-10 C hydrocarbon group) and/or alkoxy- substituted alkyl acrylate of formula III (wherein R<5> is a 2-10 C hydrocarbon group; and R<6> is a 1-10 C hydrocarbon group), 0.1-10wt. % crosslinking monomer (e.g. butadiene) and 0-30 wt. % copolymerizable unsaturated monomer. An acrylic copolymer rubber of a Mooney viscosity >=15 is obtained by polymerizing the obtained mixture by using a radical polymerization initiator.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides heat resistance,
This invention relates to an acrylic copolymer rubber with excellent cold resistance and oil resistance, and a method for producing the same.

[Conventional technology]

Traditionally, natural rubber, styrene-butadiene copolymer rubber (SBR),
Polybutadiene rubber (BR), polyisoprene rubber (I
R), butyl rubber (IIR), acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber (CR)
, ethylene-propylene-diene ternary copolymer rubber (EP
DM) and acrylic rubber (ACM) are known.

However, in recent years, rubber, which is an industrial material, is required to have advanced functions that cannot be satisfied at the conventional levels of heat resistance, cold resistance, and oil resistance.

In order to improve the physical properties of these rubbers, changes are mainly made to the polymer composition and the types and amounts of compounding agents.

However, even if these changes are made, it is difficult to improve all of the heat resistance, cold resistance, and oil resistance.

For example, in acrylonitrile looptadiene copolymer rubber, increasing the acrylonitrile content improves oil resistance and
Although it is possible to improve heat resistance, cold resistance deteriorates. Therefore, attempts have been made to introduce unsaturated carboxylic acid esters as a means to improve the heat resistance, cold resistance, and oil resistance of acrylonitrile-butadiene copolymer rubber. However, although this method improves heat resistance, cold resistance and oil resistance deteriorate.

In addition, for acrylic rubber, a method is known to improve cold resistance by introducing 2-methoxyethyl acrylate as the main monomer [Journal of the Japan Rubber Association, 53 (6) P.
367 (1980)).

However, although this method improves oil resistance, heat resistance deteriorates.

Furthermore, as a method for improving low temperature properties without impairing oil resistance and heat resistance, a method is known in which a (meth)acrylic ester of an ε-caprolactone adduct of a l-valent saturated alcohol is copolymerized with ethyl acrylate. (Unexamined Japanese Patent Publication No. 63-2
68717). However, with this method, ■
As the amount of copolymerized (meth)acrylic acid ester of ε-caprolactone adduct of a saturated alcohol increases, the glass transition temperature decreases, but the compression set properties at low temperatures decrease.
It could not be said that it exhibited practically sufficient low-temperature properties.

(Problems to be Solved by the Invention) The present invention has been made against the background of the above-mentioned problems of the prior art. An object of the present invention is to provide an acrylic copolymer rubber from which a rubber composition can be obtained, and a method for producing the same.

[Means to solve the problem]

The present invention is based on (A) general formula (1). ．． ．． ．． , (1) (wherein Rl is a hydrogen atom or a methyl group, R2 is an alkylene group having 3 to 20 carbon atoms, R3 is a hydrocarbon group having 1 to 20 carbon atoms or a derivative thereof, and l is an integer of 1 to 20. 5 to 30% by weight of (meth)acrylic ester (hereinafter referred to as "(meth)acrylic ester (I)") represented by
, (B) General formula (II) CHt==CH-C-0-R4 ・− ・− ・
(n) 11 0 (in the formula, R4 represents a hydrocarbon group having 3 to 10 carbon atoms) (hereinafter referred to as "acryno-U acid alkyl ester (■)") and/or the general formula (In) CHt-richCl{-C-0-RS-OR"11 0... (III) (wherein, RS is a hydrocarbon group having 2 to 10 carbon atoms, and R6 is a hydrocarbon group having 1 to 10 carbon atoms. acrylic acid alkoxy-substituted alkyl ester (hereinafter referred to as "acrylic acid alkoxy-substituted alkyl ester (■)") 50 to 94.9% by weight, (C) crosslinkable monomer 0.1 ~10% by weight, and (D)
Unsaturated monomer O copolymerizable with the components (A) to (C) above
Mooney viscosity (ML, .4, 10
The present invention provides an acrylic copolymer rubber having 0"C) of 15 or more and a method for producing the same.

First, (meth)acrylic acid ester (1
), in the general formula (1), R'
is a hydrogen atom or a methyl group, preferably a hydrogen atom.

Further, R2 is an alkylene group having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, and examples thereof include a propylene group and a butylene group.

Further, R3 is a hydrocarbon group having 1 to 20 carbon atoms, or a derivative of a hydrocarbon group containing an oxygen atom, a nitrogen atom, a halogen atom, etc., and preferably 1 to 1 carbon atoms.
O is a hydrocarbon group.

This hydrocarbon group having 1 to 10 carbon atoms includes a methyl group,
Alkyl groups such as ethyl group and butyl group; aromatic hydrocarbon groups such as phenyl group, tolyl group and xylyl group; alicyclic hydrocarbon groups such as cyclopentyl group and cyclohexyl group; preferred are alkyl groups;゛Preferable are methyl group and ethyl group.

Furthermore, in general formula (1), l is an integer of 1 to 20, preferably 1 to 10.

(Meth)acrylic acid ester represented by general formula (1) (
Specific examples of 1) include the following compounds.

CH! =CHCOO C3 H6CO. OCH
3.CHZ=CHCOO Ca He Coo
CH3, CHt=CHCOO-CS H,. Coo-
CH,,CH! =CHC○OCsH+. Coo-C,H
S, CH,=CHC00-CS H+1IcOO-C4
H9, CH. =CHCOO-C,H,. COO-C.
H. ,,CH. C H Z CH2 CH. CH2 CH2 CH2 =CHCO○1=CHCOO- =CHCOO- =CHCOO- =CHCOO- =CHCO○1=CHCOO- (Cs (C4 (Cs (CS (CS (CS (C, H.COO) H.Coo) H,.COO) H..COO) H..COO) H..COO) H..COO) Cz Cz Cz -C! -C! -C2 -CCl H,, HS% H,, H,, H,, H,, Hat・ The (meth)acrylic acid ester (1) is, for example, an unsaturated carboxylic acid represented by the following general formula (IV) (hereinafter referred to as "unsaturated carboxylic acid (■)") and an alcohol represented by the following general formula (V) (hereinafter referred to as "alcohol (V)").

．． ．． ．． ．． ．． (IV) [wherein R I , R 2 and l represent the general formula (
Same as 1). ] R'-OH,, . ．． , (y) [
In the formula, R3 is the same as in the above general formula (1). ] The alcohols (IV) used in the conoesterification reaction include methyl alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol, hexyl alcohol, 2-
Examples include aliphatic alcohols such as ethylhexyl alcohol; alicyclic alcohols such as cyclopentanol and cyclohexanol; and aromatic alcohols such as benzyl alcohol. Among these, aliphatic alcohols are preferred from the viewpoint of the balance between oil resistance and cold resistance of the resulting copolymer rubber, and methyl alcohol and ethyl alcohol are even more preferred. This esterification reaction is preferably carried out in the presence of a catalyst. Esterification catalysts include inorganic acids such as sulfuric acid and hydrochloric acid, aromatic compounds and sulfonic acid derivatives such as formic acid, acetic acid, propionic acid, p-toluenesulfonic acid, phosphorus oxychloride, polyphosphoric acid, boron trifluoride, and phosphorus pentoxide. Examples include.

These catalysts are characterized by the fact that all reactants [unsaturated carboxylic acid (IV)
+alcohol (■)], usually 0.01-10
It can be used in a range of 0.1 to 5% by weight, and is preferably used in a range of 0.1 to 5% by weight.

This esterification reaction is an equilibrium reaction, and in order to transfer the equilibrium reaction to a production system, for example, (1) using a large excess of alcohol, (2) using benzene or tonoleene as a vehicle, and Methods include separating raw water by azeotropic distillation using a water tank, or placing a desiccant such as anhydrous magnesium sulfate or molecular sieve 5A in a Soxhlet extractor and refluxing the solvent for dehydration. Implemented.

The reaction temperature for esterification is usually in the range of 0 to 200°C, preferably o-too''C.

This esterification reaction can also be carried out using a solvent. Examples of the medium include aromatic solvents such as benzene, toluene, and xylene, as well as ethers, aliphatic hydrocarbons,
Esters etc. can be used. Among these solvents, benzene, toluene, xylene, n-hexane, etc. are preferred because they can be easily and smoothly distilled out of the system by azeotropically forming water produced by the esterification reaction. In addition, in order to prevent gelation due to radical polymerization during the esterification reaction, 50 to 1,000 ppm of a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, methyl hydroquinone, p-penzoquinone, or phenothiazine should be added to the reaction solution. is preferred.

The completion of the esterification reaction can be confirmed by measuring the amount of water produced and distilled off. Another method for obtaining the (meth)acrylic ester (1) is to use a (meth)acrylic ester represented by the following general formula (Vl) and a hydroxy ester represented by the following general formula (■). An example of a method is to combine these by a so-called transesterification reaction, in which the alcohol that is eliminated by heating in the presence of a catalyst is distilled out of the reaction system. R1 [wherein, Rl is the same as in the general formula (1) above, and R4 represents a hydrocarbon group having 1 to 20 carbon atoms or a derivative thereof. ] HO- (R"-C-0) Il-R3... (
■) 11 0 [In the formula, Rf , R3 and 1 are the same as in the above general formula (1). ] Note that the catalyst, solvent, and polymerization inhibitor used in this transesterification reaction can be the compounds used in the esterification reaction described above.

A useful copolymer rubber of the present invention can be obtained by copolymerizing the (meth)acrylic acid ester (1) of the present invention with other monomers described below.

At this time, the content of (meth)acrylic acid ester (1) in the copolymer rubber is 5 to 30% by weight, preferably 10 to 30% by weight.
If it is less than 5% by weight, the effect of improving the low temperature properties of the obtained copolymer rubber will be small, while if it exceeds 30% by weight, the compression set properties and tensile strength at low temperatures will deteriorate.

Next, R4 of the acrylic acid alkyl ester (II) represented by the general formula (n), which is one component of component CB), is a proyl group, n-butyl group, hexyl group, 2-
Ethylhexyl group, isobutyl group, pentyl group, 2-methylpentyl group, isoaxiyl group, n-octyl group, n-
Examples include decyl group, n-dodecyl group, and n-octadecyl group. Specific examples of acrylic acid alkyl ester (n) include:
These include probyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, with n-butyl acrylate being preferred.

In addition, the other component of component (B) is the general formula (I[I)
R5 in the acrylic acid alkoxy-substituted alkyl ester (III) represented by is ethylene group, propylene group, butylene group, Rh is methyl group, ethyl group, n-butyl group, n
-probyl group, n-octyl group, n-bentyl group, etc.

Acrylic acid alkoxy-substituted alkyl ester (I[[)
Specific examples include 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2-(n-proboxy)ethyl acrylate, 3-methoxybrobyl acrylate, and 3-methoxyethyl acrylate. Ethoxib pill and the like, preferably 2-methoxyethyl acrylate.

The content of component (B) in the copolymer rubber is 50 to 94.
9% by weight, preferably 60 to 90% by weight; less than 50% by weight results in insufficient low temperature properties;
If it exceeds % by weight, oil resistance and heat resistance will be poor.

Next, examples of the crosslinkable monomer for (C)Fj; c include the following compounds. ■Diene monomer, ■Unsaturated carboxylic acid ester containing unsaturated group, ■Vinyl monomer containing epoxy group, ■Vinyl monomer containing carboxyl group, ■Vinyl monomer containing reactive halogen atom, ■Containing hydroxyl group Vinyl monomer, ■ Vinyl monomer containing amide group.

Here, ■ diene monomers include butadiene, ethylidene norbornene, isoprene, biperylene,
Divinylbenzene, vinylcyclohexene, chloroprene, methylbutadiene, cyclopentadiene, methylpentadiene, dimethylvinylstyrylsilane, etc.
As an unsaturated carboxylic acid ester containing an unsaturated group. , such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dihydrodicyclopentadienyl(meth)acrylate, dihydrodicyclobentadienyloxyethyl(meth)acrylate, vinyl(meth)acrylate, dimethylvinylmethacryloxy Methylsilane, etc.; (1) Eboxy group-containing vinyl monomers include, for example, glycidyl (meth)acrylate, allyl glycidyl ether; (2) Carboxyl group-containing vinyl monomers, such as (meth)acrylic acid, itaconic acid, Mono n-butyl fumarate, monoethyl maleate, mono n-butyl maleate, 2-methacryloyloxyethylsuccinic acid, 2-methacryloyloxyethyl phthalate, 2-methacryloyloxyethyl hexahydrophthalic acid, 2 - methacryloyloxyethylmaleic acid, etc.; ■ Reactive halogen atom-containing vinyl monomers include, for example, 2-chloroethyl vinyl ether, vinyl chloroacetate, allyl chloroacetate, chloromethylstyrene, etc.; ■ hydroxyl group-containing vinyl monomers. For example, 2-hydroxyethyl acrylate, 2-
Hydroxypyl methacrylate, 2-hydroxyethyl methacrylate, N-methylol (meth)acrylamide, etc.;
Examples include acrylamide and methacrylamide.

The content of the crosslinkable monomer (C) in the copolymer rubber is 0.
1 to 10% by weight, preferably 0.1 to 5% by weight,
If it is less than 0.1% by weight, the resulting copolymer rubber will have poor tensile strength, while if it exceeds 10% by weight, its elongation will tend to decrease.

Next, unsaturated monomers (D) copolymerizable with the components (A) to (C) include (meth)trifluoroethyl (meth)acrylate, pentafluoropropyl (meth)acrylate, and the like. ) Carboxylic acid vinyl esters such as perfluoroalkyl acrylate, vinyl acetate, vinyl propionate, and vinyl cabroate, vinyl cyanide compounds such as (meth)acrylonitrile, α-methylacrylonitrile, methyl (meth)acrylate, (meth) )
Ethyl acrylate, styrene, ethylene, vinyl chloride,
Examples include vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, and the like.

The content of (D) unsaturated monomer in the copolymer rubber is 30
It can be copolymerized in a range of up to 20% by weight, preferably up to 20% by weight, and when it exceeds 30% by weight, (A), (B)
IIi. The amount of water is reduced, and the balance between cold resistance and oil resistance cannot be achieved.

The copolymerization method for the acrylic copolymer rubber of the present invention includes conventional emulsion polymerization, suspension polymerization,
It can be easily produced by bulk polymerization or solution polymerization.

As an emulsifier when producing a copolymer rubber by emulsion polymerization, an anionic or nonionic surfactant may be used alone or as a mixture, and various dispersants may also be used. Examples of these emulsifiers include alkyl sulfates, alkylaryl sulfonates, salts of higher fatty acids, such as polyoxyethylene alkyl ether sulfate salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, and polyoxyethylene fatty acid esters. , polyoxyethylene oxypropylene block polymer, and the like.

The copolymerization reaction can be carried out at a temperature of -lOO to +200'C, preferably 0 to +60'C.

Examples of radical initiators for initiating polymerization include organic peroxides such as penzoyl peroxide, cumene hydroperoxide, and paramencun hydroperoxide, organic hydroperoxides such as hydroperoxide, and t-butyl hydroperoxide. oxide, azo compounds represented by azobisisoprodylonitrile, inorganic persulfates such as potassium persulfate and ammonium persulfate,
Examples include redox catalysts typified by a combination of organic peroxides and iron monosulfate.

These radical initiators are usually used at a concentration of 0.0% relative to the monomer mixture. Ol~2% by weight is used.

Molecule IIIJ1 moderators are used as necessary, and specific examples thereof include t-dodecylmercabutane, dimethylxanthogen disulfide, and the like. After the polymerization reaction reaches a predetermined polymerization conversion rate, N,N-
The polymerization reaction is stopped by adding a reaction terminator such as diethyl hydroxide, and then unreacted monomers in the resulting latex are removed by steam distillation, and anti-aging agents such as phenols and amines are added. A copolymer can be produced by adding the latex and coagulating the latex using a conventional coagulation method, for example, by mixing with an aqueous metal salt solution such as an aqueous solution of aluminum sulfate, an aqueous calcium chloride solution, an aqueous sodium chloride solution, or an aqueous solution of ammonium sulfate, and then drying the latex. You can get rubber. In addition, when producing copolymer rubber by Qi radical polymerization, saponified polyvinyl alcohol is added as a dispersant, and polymerization is carried out using an oil-soluble radical initiator such as azobisisobutyronitrile or penzoyl peroxide. After polymerization is complete, copolymer rubber can be obtained by removing water. Furthermore, when producing copolymer rubber by solution radical polymerization, generally known methods can be employed. The polymerization method can be either continuous or batchwise.

The molecular weight of the copolymer rubber of the present invention thus obtained is determined by various factors such as the type and amount of the molecular weight regulator, the type and amount of the radical initiator, the polymerization temperature, the type and amount of the solvent, and the monomer concentration. By changing the reaction conditions, a viscosity average molecular weight of 1 to 5,000,000, preferably 10 to 2,000,000 can be obtained. In addition, the Mooney viscosity (ML..., 100"C) of the obtained copolymer rubber is 15 or more, preferably 15 to 100; if it is less than 15, the copolymer rubber has poor tensile strength, and on the other hand, 100" Exceeding this is not preferable since workability may deteriorate.

The acrylic copolymer rubber of the present invention can be blended with a vulcanization accelerator, a crosslinking agent, etc., and then vulcanized by a commonly known vulcanization method.

As the crosslinking agent, the following can be selected depending on the type of crosslinkable monomer (C) used in the copolymerization.

That is, the crosslinking monomer is a diene monomer and/or
Alternatively, in the case of an unsaturated carboxylic acid ester containing an unsaturated group, sulfur, an organic sulfur-containing compound, or an organic peroxide is used as a crosslinking agent.

In addition, when an epoxy group-containing vinyl monomer is used as a crosslinkable monomer, polyamine, polycarboxylic acid,
Acid anhydrides, polyamides, sulfonamides, dithiocarbamates, organic ammonium carboxylates, and the like are used as crosslinking agents.

Further, when a carboxyl group-containing vinyl monomer is used as the crosslinking monomer, polyamines, polyeboxides, polyols, etc. are used as the crosslinking agent.

Furthermore, when (1) a reactive halogen atom-containing vinyl monomer is used as a crosslinking monomer, metal soaps, ammonium salts of organic carboxylic acids, polyamines, polycarbamates, trithiocyanuric acid, etc. are used as crosslinking agents.

Furthermore, when a hydroxyl group-containing vinyl monomer is used as a crosslinking monomer, polyisocyanate, polycarboxylic acid, alkoxymethyl melamine, etc. are used as a crosslinking agent.

Furthermore, when an amide group-containing vinyl monomer is used as a crosslinkable monomer, acnoformaldehyde or the like is used as a crosslinking agent.

Among these crosslinking agents, unmixed sulfur,
Any of precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly degradable sulfur can be used.

The organic sulfur-containing compound is a compound that releases active sulfur by thermal dissociation, and includes, for example, thiuram promoters such as tetramethylthiuram disulfide and 4,4'-dithiomorpholine.

Examples of organic peroxides include 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(L-butylperoxy)hexane, 1.
3-bis(L-butylperoxyisobutyl)benzene, dicumyl peroxide, dibutyl peroxide, 1.1-di-L-butylperoxy-3.3.5-trimethylcyclohexane, t-butylcumyl Peroxide, L-butylperoxyisopropylene carbonate, etc. are used.

Examples of metal oxides include zinc oxide, magnesium oxide, and lead oxide.

Examples of the quinone dioxime include p-quinone dioxime and P,P'-dibenzoylquinone oxime.

Examples of modified alkylphenol resins include alkylphenol formaldehyde resins and brominated alkylphenol formaldehyde resins.

Examples of the polyisocyanate include hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and the like.

As the borian ξane, for example, triethylenetetramine,
Examples include methylene dianiline and diethylene triamine.

Examples of metal soaps include sodium stearate and potassium stearate.

Examples of organic carboxylic acid ammonium salts include ammonium benzoate and ammonium adibate.

Examples of polycarboxylic acids include adipic acid and octadecyldicarboxylic acid.

Examples of the acid anhydride include pyromellitic anhydride, maleic anhydride, and dodecenylsuccinic anhydride.

Examples of the dithiocarbamic acid include hexamethylene diamine carbamate, zinc dimethyl dithiocarbamate, and the like.

Examples of the polyeboxide include ethylene glycol diglycidyl ether and 1,6-hexanediol diglycidyl ether.

Examples of the polyol include 1,4-butanediol,
Examples include 1,1,1-1-limethylolpropane.

A crosslinking aid can be added to these crosslinking agents in order to shorten the crosslinking time, lower the crosslinking temperature, and improve the performance of the crosslinked product.

For example, when using sulfur as a crosslinking agent, thiazoles such as mercaptobenzothiazole, thiurams such as tetramethylthiuram disulfide, guanidines such as diphenylguanidine, dithiocarbamates such as zinc dimethyldithiocarhamate, etc. can be effectively used as a crosslinking aid.

When using an organic peroxide as a crosslinking agent, ethylene glycol dimethacrylate, 1. 3=butanediol dimethacrylate, 1.4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, polyethylene glycol dimethacrylate, 1.4-butanediol diacrylate, 1.6-
Hexanediol diacrylate, 2,2'-bis(4
-methacryljethoxyphenyl)propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, divinylbenzene, N,N'-methylenebisacrylate, p-quinonedioxime, p
, ρ'-dibenzoylquinone dioxime, triazine dithiol, triallyl cyanurate, triallylisocyanurate, bismaleimide, silicone oil with a high vinyl content, and the like can be effectively used as crosslinking aids.

When using a metal oxide as a crosslinking agent, for example, dibentamethylenethiuram tetrasulfide can be effectively used as a crosslinking aid if necessary.

When using quinone dioxime as a crosslinking agent, an oxidizing agent such as red lead can be effectively used as a crosslinking aid.

When using modified phenolic resin as a crosslinking agent,
For example, halides such as chlorinated polyethylene and tin chloride can be effectively used as crosslinking aids. When a metal soap is used as a crosslinking agent, for example, sulfur or dipentamethylenethiuram tetrasulfide can be effectively used as a crosslinking aid.

When using an amine as a crosslinking agent, for example, diphenylguanidine and diorthotolylguanidine can be effectively used as a crosslinking aid.

When trithiocyanuric acid is used as a crosslinking agent, dithiocarbamates, metal oxides, alkali metal salts of organic carboxylic acids, dicyandiamide and aluminum-containing compounds can be effectively used as crosslinking aids.

The amount of these crosslinking agents in the rubber composition of the present invention is usually 0.1 to 10 parts by weight, and 0.1 parts by weight per 100 parts by weight of the acrylic copolymer rubber. If it is less than 10 parts by weight, crosslinking will hardly proceed, while if it exceeds 10 parts by weight, the physical properties of the resulting copolymer rubber composition will be impaired, which is not preferable.

The copolymer rubber of the present invention is prepared by adding various compounding agents as necessary in addition to the above-mentioned crosslinking agent, and mixing the mixture using a conventional mixer such as a two-roll mixer or a Banbury mixer. .

Among the compounding agents, fillers include carbon black and white fillers such as silica, calcium carbonate, talc, and magnesium carbonate. In addition, among the compounding agents, examples of dispersants include higher fatty acids and their metal salts or amide salts; plasticizers include:
For example, phthalic acid derivatives, adipic acid derivatives, polyether esters; softening agents, such as lubricating oils, process oils, castor oil; anti-aging agents, such as 4.4
Amines such as '-(α,α-dimethylbenzyl)diphenyluane Foaming agents, anti-scorch agents, tackifiers, lubricants, etc. can be added as desired. The rubber composition containing the copolymer rubber of the present invention obtained in this way as a main component can be shaped and crosslinked to form a crosslinked product under normal crosslinked rubber manufacturing conditions. That is, after the precept, it is usually 150 to 180°C for 10 to 60 minutes.
Primary crosslinking under heating and pressure of 50 to 1' 50 kg/cd, and further crosslinking as necessary to 150 to 180'
By performing secondary crosslinking with C for 1 to 20 hours, a crosslinked product having excellent heat resistance, cold resistance, and oil resistance can be obtained.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded.

In the examples, parts and percentages are based on weight unless otherwise specified.

In addition, in the examples, the methods for measuring various properties of the copolymer rubber and crosslinked product are as follows.

The chlorine content in the polymers of chlorvinyl and chloralyl was determined by measuring by fluorescent X-ray method.

After dissolving PoIJ7-4 of allylg tau sidyl ale in chloroform, the epoxy equivalent was determined by the acetic acid method.

The quantitative determination of acrylic acid esters such as butyl acrylate and 2-methoxyethyl acrylate in the alcohol of rubber was determined from 13C nuclear magnetic resonance spectroscopy.

A rubber sheet or block was prepared from a composite material containing an acrylic copolymer rubber, and crosslinked for a predetermined period of time using a crosslinking press device. In addition, crosslinking was further carried out for a predetermined time using a gear oven if necessary.

The obtained crosslinked sheet or block was shaped using a dumbbell cutter, and its heat resistance, cold resistance, compression set, and oil resistance were measured in accordance with JIS K6301.

Examples 1 to 5, Comparative Examples 1 to 4 (Production of acrylic copolymer rubber) 100 parts of monomer mixture, 4 parts of sodium lauryl sulfate, 0.25 parts of ρ-menthane hydroperoxide, sulfuric acid 0.01 part of the first tank, 0.025 part of sodium ethylenediaminetetraacetate, and 0.04 part of sodium formaldehyde sulfoxylate were charged into an autoclave purged with nitrogen, and the monomer conversion rate was increased at a reaction temperature of 30°C. 9
The reaction was continued until the concentration reached 0%, and 0.5 part of N,N-diethylhydroxylamine was added to stop the reaction.

Next, the reacted raw materials were taken out and steam was blown into them to remove unreacted monomers. The rubber latex thus obtained was coagulated by adding it to a 0.25% calcium chloride aqueous solution, and the coagulated product was thoroughly washed with water and dried at about 90°C for 3 hours to obtain a copolymer corresponding to Example 1. I got an A.

The composition of copolymer A was calculated from the chemical shift of the C-NMR spectrum. However, the vinyl chloroacetate content and allyl chloroacetate content were determined by fluorescent X-ray method, and allyl glycidyl ether was determined from the quantification of epoxy groups. The results are shown in Table I.

Copolymer rubber B-1 was also produced in the same manner.

Next, 100 parts of each copolymer rubber obtained was added with 60 parts of FEF carbon plaque, 1 part of stearic acid, and the additions shown in Table 2 depending on the type of crosslinkable monomer used in the production of each copolymer rubber. A sulfur accelerator and a crosslinking agent were added and mixed with a roll, and then crosslinked at 170'C for 20 minutes to produce a crosslinked sheet and block. The crosslinked sheets and blocks were further crosslinked in an oven at 175°C for 4 hours.

The resulting crosslinked sample was measured for tensile strength, cold resistance, and oil resistance in accordance with JIS K6301. The results are shown in Table 2.

From the results in Table 2, the rubber composition using the acrylic copolymer rubber of the present invention has a better balance of heat resistance, cold resistance, and oil resistance than the conventional copolymer rubber using acrylic acid ester. It can be seen that it has excellent compression set properties, especially at low temperatures.

(The following is a blank space) (Effects of the Invention) The acrylic copolymer rubber of the present invention has excellent properties in tensile strength, heat resistance, cold resistance (particularly compression set properties at low temperatures), and oil resistance.

Taking advantage of these properties, the acrylic copolymer rubber of the present invention can be used in various industrial materials such as hair ring seals, oil seals, packings, gaskets, O-rings, and other sealing materials, as well as belts, hoses, and rolls. It can be used in rubber-coated fabrics, rubber gloves, additives for synthetic resins, adhesives, etc.

Claims (2)

[Claims] (1) (A) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) (In the formula, R^1 is a hydrogen atom or a methyl group, R^2 is a carbon number of 3 to 20 alkylene group, R^3 has 1 to 20 carbon atoms
5 to 30% by weight of a (meth)acrylic ester represented by a hydrocarbon group or a derivative thereof, l is an integer of 1 to 20)
, (B) General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (In the formula, R^4 represents a hydrocarbon group having 3 to 10 carbon atoms) Acid alkyl ester and/or general formula (III) ▲Mathematical formulas, chemical formulas, tables, etc.▼...(III) (In the formula, R^5 is a hydrocarbon group having 2 to 10 carbon atoms, R^6
represents a hydrocarbon group having 1 to 10 carbon atoms) acrylic acid alkoxy-substituted alkyl ester 50 to 94.9
% by weight, (C) 0.1 to 10% by weight of crosslinkable monomer, and (D)
0 unsaturated monomers copolymerizable with the components (A) to (C) above
Mooney viscosity (ML_1_+_4
, 100°C) is 15 or more. (2) By polymerizing the components (A), (B), (C) and (D) using a radical polymerization initiator, (
An acrylic copolymer having a polymer composition of A) component 5 to 30% by weight, (B) component 50 to 94.9% by weight, (C) component 0.1 to 10% by weight, and (D) component 0 to 30% by weight. Method for producing polymer rubber.