JPH05262831A - Production of acrylic copolymer rubber - Google Patents

Abstract

PURPOSE:To obtain the title rubber excellent in heat resistance, low-temperature resistance and oil resistance by radical-polymerizing a (meth)acrylic ester with an alkyl acrylate and/or an alkoxyalkyl acrylate, chlorinated and/or epoxidized cross-linking monomers, and a polyene monomer. CONSTITUTION:A (meth)acrylic ester of formula I (wherein R<1> is hydrogen or methyl; R<2> is 3-20 C alkylene; R<3> is a 1-20 C hydrocarbon group or its derivative; and l is an integer of 1-20), an alkyl (meth)acrylate of formula II (wherein R<4> is a 1-20 C hydrocarbon group) and/or an alkoxyalkyl acrylate of formula III (wherein R<5> is a 2-10 C hydrocarbon group; and R<6> is a 1-10 C hydrocarbon group), a chlorinated and/or epoxidized cross-linking monomers, a polyene monomer, and an unsaturated monomer copolymerizable therewith are polymerized in the presence of a radical polymerization initiator.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an acrylic copolymer having heat resistance, cold resistance and oil resistance suitable for industrial materials and having good kneading processability, roll processability and extrusion properties. The present invention relates to a method of manufacturing rubber.

[0002]

2. Description of the Related Art Conventionally, as a rubber for industrial materials mainly for automobile parts, natural rubber, styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), polyisoprene rubber (IR), butyl rubber (IIR), Acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber (CR), ethylene-propylene-diene terpolymer rubber (EPDM), and acrylic rubber (AC
M) and the like are known. However, in recent years,
With respect to rubber of such an industrial material, at a conventional level of heat resistance, cold resistance, and oil resistance, a high level of function that cannot satisfy the required performance is being demanded.

In order to improve the physical properties of these rubbers, mainly rubber is used.
Change of limer composition, change of combination type and amount
Has been done. However, making these changes
However, it is not possible to improve heat resistance, cold resistance, and oil resistance.
Have difficulty. For example, acrylonitrile-butadiene copolymer
In polymerized rubber, to increase the content of acrylonitrile
Although it is possible to improve oil resistance and heat resistance,
Cold resistance deteriorates. Therefore, acrylonitrile-butadiene
Improve the heat resistance, cold resistance and oil resistance of ene copolymer rubber
Introducing unsaturated carboxylic acid ester
Is being attempted. However, with this method,
Although heat resistance is improved, cold resistance and oil resistance deteriorate.
I will. For acrylic rubber, as the main monomer
Improved cold resistance by introducing 2-methoxyethyl acrylate
There are known ways to do good [Journal of Japan Rubber Association,53
(6) P367 (1980)]. However, this person
Although the oil resistance is improved by the method, the heat resistance is deteriorated.
I will.

Therefore, the applicant of the present application has proposed the above general formula (I)
By copolymerizing an ester group-containing (meth) acrylic acid ester represented by (hereinafter referred to as “(A) component” or “(meth) acrylic acid ester (I)”), heat resistance, cold resistance, and oil resistance are obtained. The inventors have found an acrylic copolymer rubber that simultaneously satisfies the properties and has improved compression set characteristics, especially at low temperatures (JP-A-3-160008). However, this acrylic copolymer rubber cannot be said to have sufficient processability, particularly kneading processability, roll processability, and extrusion properties.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and satisfies heat resistance, cold resistance and oil resistance at the same time, and particularly has excellent compression set characteristics at low temperature, Another object of the present invention is to provide an acrylic copolymer rubber having good kneading processability, roll processability, and extrusion properties.

[0006]

The present invention provides (A) general formula (I) (In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 3 to 20 carbon atoms, R ³ is a hydrocarbon group having 1 to 20 carbon atoms or a derivative thereof, and l is an integer of 1 to 20. )
A (meth) acrylic acid ester represented by: (B) general formula (II) (Wherein R ⁴ represents a hydrocarbon group having 1 to 10 carbon atoms) and / or an alkyl acrylate represented by the general formula (III) (In the formula, R ⁵ represents a hydrocarbon group having 2 to 10 carbon atoms, and R ⁶ represents a hydrocarbon group having 1 to 10 carbon atoms), an acrylic acid alkoxy-substituted alkyl ester represented by the formula (C) chlorine-based and / Alternatively, an epoxy-based crosslinkable monomer, a (D) polyene monomer, and (E) an unsaturated monomer copolymerizable with the components (A) to (D) are polymerized using a radical polymerization initiator. (A) component 3 to 30% by weight, (B)
Component 50 to 95% by weight, component (C) 0.1 to 10% by weight, component (D) 0.01 to 5% by weight, component (E) 0 to 3
0 wt% [(A) + (B) + (C) + (D) +
(E) = 100% by weight] The present invention provides a method for producing an acrylic copolymer rubber having a polymerization composition.

First, the (meth) acrylic acid ester (I) used in the present invention will be described.
In, R ¹ is a hydrogen atom or a methyl group, preferably a hydrogen atom. R ² 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, R ³ is a hydrocarbon group having 1 to 20 carbon atoms or a derivative of a hydrocarbon group containing an oxygen atom, a nitrogen atom or a halogen atom, and preferably a hydrocarbon group having 1 to 10 carbon atoms. . Examples of the hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl group, ethyl group and butyl group; aromatic hydrocarbon groups such as phenyl group, toluyl group and xylyl group; Examples thereof include cyclic hydrocarbons, preferably an alkyl group, and more preferably a methyl group or an ethyl group. Further, in the general formula (I), l is an integer of 1 to 20, preferably 1 to 10.

The following compounds can be mentioned as specific examples of the (meth) acrylic acid ester (I) represented by the general formula (I). _{CH 2 = CHCOO-C 3 H} 6 CO
_{O-CH 3, CH 2 =} CHCOO-C 4 H 8 COO-C
_{H 3, CH 2 = CHCOO-} C 5 H 10 COO-CH 3,
_{CH 2 = CHCOO-C 5 H} 10 COO-C 2 H 5, CH
_{2 = CHCOO-C 5 H 10} COO-C 4 H 9, CH 2 =
_{CHCOO-C 5 H 10 COO-} C 8 H 17, CH 2 = CH
_{COO- (C 3 H 6 COO)} 2 -C 2 H 5, CH 2 = CHC
_{OO- (C 4 H 8 COO)} 2 -C 2 H 5, CH 2 = CHCO
_{O- (C 5 H 10 COO)} 2 -C 2 H 5, CH 2 = CHCOO
_{- (C 5 H 10 COO)} 3 -C 2 H 5, CH 2 = CHCOO-
_{(C 5 H 10 COO) 4} -C 2 H 5, CH 2 = CHCOO-
_{(C 5 H 10 COO) 5} -C 2 H 5, CH 2 = CHCOO-
_{(C 5 H 10 COO) 2} -C 8 H 17,

The (meth) acrylic acid ester (I)
Is, for example, an unsaturated carboxylic acid represented by the following general formula (IV) (hereinafter referred to as “unsaturated carboxylic acid (IV)”) and an alcohol represented by the following general formula (V) (hereinafter referred to as “alcohol (V)”). The above) can be obtained by an esterification reaction with [In formula, R < ¹ > -R < ² > and l are the same as the said General formula (I). ] R ³ -OH. ． ． ． ． (V) [In formula, R < ³ > is the same as the said General formula (I). As the alcohol (V) used in this esterification reaction, aliphatic alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol, hexyl alcohol and 2-ethylhexyl alcohol; cyclopentanol, cyclohexanol Alicyclic alcohols such as; and aromatic alcohols such as benzyl alcohol. Of these, aliphatic alcohols are preferable from the viewpoint of the balance between oil resistance and cold resistance of the obtained copolymer rubber, and methyl alcohol and ethyl alcohol are more preferable.

By copolymerizing the (meth) acrylic acid ester (I) of the present invention with another monomer described below, the useful copolymer rubber of the present invention can be obtained.
At this time, the content of the (meth) acrylic acid ester (I) in the copolymer rubber is 3 to 30% by weight, preferably 10 to
It is 20% by weight, and if it is less than 3% by weight, the effect of improving the low temperature property of the obtained copolymer rubber is small, while if it exceeds 30% by weight, the compression set characteristics and the tensile strength at low temperature are deteriorated. A specific example of the method for synthesizing the (meth) acrylic acid ester (I) is described in detail in JP-A-3-160008.

Next, one of the components (B), an alkyl acrylate (II) represented by the general formula (II)
R ⁴ has 1 to 10 carbon atoms, preferably 3 to 10 carbon atoms.
Is a hydrocarbon group. Specific examples of R ⁴ include propyl group, n-butyl group, hexyl group, 2-ethylhexyl group, isobutyl group, pentyl group, 2-methylpentyl group, isoamyl group, n-octyl group, n-decyl group, n
Examples include -dodecyl group and n-octadecyl group.
Specific examples of the acrylic acid alkyl ester (II) include:
Propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate and the like are preferable, and n-butyl acrylate is preferable. Further, in the acrylic acid alkoxy-substituted alkyl ester (III) represented by the general formula (III) which is the other component of the component (B), R ⁵ is an ethylene group, a propylene group, a butylene group, R ⁶ is a methyl group, Ethyl group, n-
Examples thereof include a butyl group, an n-propyl group, an n-octyl group and an n-pentyl group.

Specific examples of the acrylic acid alkoxy-substituted alkyl ester (III) include 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, and 2-acrylic acid acrylate.
Butoxyethyl, 2- (n-propoxy) ethyl acrylate, 3-methoxypropyl acrylate, acrylic acid 3
-Ethoxypropyl and the like, preferably 2-methoxyethyl acrylate. The content of the component (B) in the copolymer rubber is 50 to 95% by weight, preferably 60 to 9%.
When it is 0% by weight and less than 50% by weight, low temperature properties are insufficient, while when it exceeds 95% by weight, oil resistance and heat resistance are poor.

Next, examples of the chlorine-based or epoxy-based crosslinkable monomer as the component (C) include the following compounds. First, examples of the chlorine-based crosslinkable monomer include a reactive halogen atom-containing vinyl monomer, and specific examples thereof include 2-chloroethyl vinyl ether, vinyl chloroacetate, allyl chloroacetate, and chloromethylstyrene. Be done. Examples of the epoxy crosslinkable monomer include glycidyl (meth) acrylate and allyl glycidyl ether. These (C) crosslinkable monomers may be used alone or in admixture of two or more.
The content of the component (C) in the copolymer rubber is 0.1-10.
% By weight, preferably 0.1 to 5% by weight. When the amount is less than 0.1% by weight, the copolymer rubber obtained has poor tensile strength.
On the other hand, if it exceeds 10% by weight, the elongation tends to decrease.

Next, the (D) component polyene monomer is
It is a monomer having two or more non-conjugated double bonds and causing a crosslinking reaction during the copolymerization reaction. Specific examples of the (D) polyene monomer include divinylbenzene, divinyl sulfide, divinyl sulfone, divinyl oxalate,
N, N-methylenebisacrylamide, allyl acrylate, allyl methacrylate, vinyl acrylate, vinyl methacrylate, allyl vinyl ether, allyl acrylamide, allyl methacrylamide, diallyl acrylamide, diallyl ether, diallyl oxalate, diallyl malonate, diallyl adipate, ethylene glycol Diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, butanediol dimethacrylate, hexanediol diacrylate, glycerin dimethacrylate, bisphenol A diacrylate, dicyclopentadienyl diacrylate Trimethylolpropane triari Ether, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate. The content of the (D) polyene monomer in the copolymer rubber is 0.01 to 5% by weight, preferably 0.01 to 0.1.
If the amount is less than 0.01% by weight, the processability improving effect is small. On the other hand, if the amount exceeds 5% by weight, gelation of the acrylic copolymer rubber is promoted, which makes it difficult to disperse carbon and not only the crosslinked product. The elongation tends to decrease significantly.

Next, examples of the (E) unsaturated monomer copolymerizable with the components (A) to (D) include trifluoroethyl (meth) acrylate and pentafluoropropyl (meth) acrylic acrylate. Perfluoroalkyl (meth) acrylate; carboxylic acid vinyl esters such as vinyl acetate, vinyl propionate, and vinyl caproate; vinyl cyan compounds such as (meth) acrylonitrile and α-methylacrylonitrile, methyl (meth) acrylate,
Examples thereof include ethyl (meth) acrylate, styrene, ethylene, vinyl chloride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene. The content of the (E) unsaturated monomer in the copolymer rubber can be copolymerized in the range of 30% by weight or less, preferably 20% by weight or less, and when it exceeds 30% by weight (A), The amount of the component (B) becomes small, and cold resistance and oil resistance cannot be balanced.

The method for copolymerizing the acrylic copolymer rubber of the present invention can be easily produced by ordinary emulsion polymerization, suspension polymerization, bulk polymerization or solution polymerization in the presence of a radical polymerization initiator. it can. As an emulsifier for producing a copolymer rubber by an emulsion polymerization method, an anionic or nonionic surfactant may be used alone or as a mixture, and various dispersants may be used. Examples of these emulsifiers include alkyl sulfates,
Alkylaryl sulfonates, salts of higher fatty acids, such as polyoxyethylene alkyl ether sulfate ester salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene oxypropylene block polymers, etc. To be

The copolymerization reaction is carried out at a temperature of -100 to +200.
C., preferably 0 to + 60.degree. C. As the radical initiator for initiating the polymerization,
For example, organic peroxides such as benzoyl peroxide, cumene hydroperoxide and paramenthane hydroperoxide, organic hydroperoxides such as hydroperoxide and t-butyl hydroperoxide,
Azo compounds represented by azobisisobutyronitrile,
Examples thereof include inorganic persulfates such as potassium persulfate and ammonium persulfate, and redox catalysts represented by a combination of organic peroxide-iron sulfate. These radical initiators are usually used in an amount of 0.01 to 2% by weight based on the monomer mixture.
Used.

The molecular weight modifier is used as needed, and specific examples thereof include t-dodecyl mercaptan and dimethylxanthogen disulfide. After reaching a predetermined polymerization conversion rate, the polymerization reaction is stopped by adding a reaction terminator such as N, N-diethylhydroxylamine, and then the unreacted monomer in the obtained latex is vaporized. Remove by distillation, add anti-aging agents such as phenols, amines, etc., and mix it with a usual coagulation method, for example, an aqueous solution of aluminum sulfate, an aqueous solution of calcium chloride, an aqueous solution of sodium chloride, an aqueous solution of ammonium sulfate, etc. to form a latex. A copolymer rubber can be obtained by solidifying and then drying.

When a copolymer rubber is produced by suspension radical polymerization, a saponification product of polyvinyl alcohol or the like is added as a dispersant, and an oil-soluble radical initiator such as azobisisobutyronitrile or benzoyl peroxide is added. It is possible to obtain a copolymer rubber by carrying out polymerization using the above and removing water after completion of the polymerization. Further, in the case of producing a copolymer rubber by solution radical polymerization, a generally known method can be adopted. The polymerization method may be either continuous or batch.

The molecular weight of the copolymer rubber of the present invention thus obtained depends on 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. By changing the reaction conditions such as the concentration, the viscosity average molecular weight is 1 to 5,000,000, preferably 1
0 to 2 million can be obtained. The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the obtained copolymer rubber is 15
As described above, it is preferably 15 to 100, and when it is less than 15, the tensile strength of the copolymer rubber is inferior, and when it exceeds 100, the processability may be lowered, which is not preferable.

The acrylic copolymer rubber of the present invention can be vulcanized by a generally known vulcanization method by adding a vulcanization accelerator, a crosslinking agent and the like. As the cross-linking agent, the following can be selected depending on the type of the (C) cross-linking monomer used for the copolymerization. That is, when the crosslinkable monomer is a chlorine-based crosslinkable monomer, metal soap, organic carboxylic acid ammonium salt, polyamine, polycarbamate, trithiocyanuric acid, etc. are used as the crosslinker. When an epoxy-based cross-linking monomer is used as the cross-linking monomer, polyamine, polycarboxylic acid, acid anhydride, polyamide, sulfonamide, dithiocarbamate, ammonium organic carboxylate or the like is a cross-linking agent. Used as. As the cross-linkable monomer (C), there are diene-based monomers which are excellent in peroxide crosslinking, but when a polyene monomer is used in this system, the crosslinking is significantly advanced and the elongation is greatly reduced. Not preferable.

Among these, examples of the metal soap include sodium stearate and potassium stearate. Examples of the organic carboxylic acid ammonium salt include ammonium benzoate and ammonium adipate. Examples of polyamines include triethylenetetramine, methylenedianiline, and diethylenetriamine. Examples of the polycarboxylic acid include adipic acid and octadecyldicarboxylic acid. Examples of the acid anhydride include pyromellitic dianhydride, maleic anhydride, dodecenyl succinic anhydride, and the like. Examples of the dithiocarbamate salt include hexamethylenediamine carbamate and zinc dimethyldithiocarbamate.

A cross-linking aid can be added to these cross-linking agents in order to shorten the cross-linking time, lower the cross-linking temperature, and improve the performance of the cross-linked product. For example, when a metal oxide is used as a cross-linking agent, dipentamethylene thiuram tetrasulfide can be effectively used as a cross-linking aid if necessary. When a metal soap is used as a crosslinking agent, for example, sulfur or dipentamethylene thiuram tetrasulfide can be effectively used as a crosslinking aid. When an amine is used as a crosslinking agent, for example, diphenylguanidine and diorsotolylguanidine can be effectively used as a crosslinking aid. When using trithiocyanuric acid as a cross-linking agent, dithiocarbamate, metal oxide,
Alkali metal salts of organic carboxylic acids, dicyandiamide and aluminum-containing compounds can be effectively used as crosslinking aids. The compounding amount of these crosslinking agents in the rubber composition of the present invention is usually 0.1 to 10 parts by weight relative to 100 parts by weight of the acrylic copolymer rubber, and 0.1 parts by weight. If it is less than 10 parts by weight, crosslinking hardly progresses, while if it exceeds 10 parts by weight, the physical properties of the obtained copolymer rubber composition are impaired, which is not preferable.

The copolymer rubber of the present invention is prepared by adding various compounding agents, if necessary, in addition to the above-mentioned cross-linking agent, and mixing them by using an ordinary mixer such as a two-roll or Banbury mixer. Is prepared. Among the compounding agents, examples of the filler include carbon black, and white fillers such as silica, calcium carbonate, talc, and magnesium carbonate. Among the compounding agents, examples of dispersants include higher fatty acids and metal salts or amide salts thereof; examples of plasticizers include phthalic acid derivatives, adipic acid derivatives, polyether esters; examples of softening agents include lubricating oils, Process oils, castor oils; Antiaging agents include amines such as 4,4 '-(α, α'-dimethylbenzyl) diphenylamine, 2,2'
-Imidazoles such as methylenebis (4-methyl-6-t-butylphenol); other pigments, crosslinking accelerators, flame retardants, foaming agents, scorch inhibitors, tackifiers, lubricants and the like can be optionally blended.

The rubber composition containing the copolymer rubber of the present invention as the main component thus obtained can be formed into a crosslinked product by molding and crosslinking under ordinary conditions for producing a crosslinked rubber. That is, after molding, it is usually 1 at 150 to 180 ° C.
Primary cross-linking under heat and pressure of 50 to 150 kg / cm ² for 0 to 60 minutes, and if necessary, at 150 to 180 ° C. for 1
Secondary cross-linking can be performed for up to 20 hours to give a cross-linked product having excellent heat resistance, cold resistance, and oil resistance.

[0026]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. In the examples, parts and% are based on weight unless otherwise specified. Also,
In the examples, the methods for measuring various properties of the copolymer rubber and the crosslinked product are as follows. Quantitative analysis of chlorovinyl acetate The chlorine content in the polymer was measured and determined by the fluorescent X-ray method. A quantitative polymer of glycidyl methacrylate was dissolved in chloroform, and then the epoxy equivalent was measured by the acetic acid method. Quantification of acrylic acid ester in copolymer rubber The quantitative determination of acrylic acid ester such as n-butyl acrylate, 2-methoxyethyl acrylate, and ethyl acrylate was determined from ¹³ C-nuclear magnetic resonance spectrum.

Evaluation of processability Kneading processability: Using a Banbury mixer with an internal volume of 1.7 liters, the time required for dispersing the acrylic copolymer rubber and carbon black was evaluated. The evaluation method is
As shown in FIG. 1, after adding carbon black,
The time to the second peak was defined as t, and this was used as an index of kneading workability. Roll processability: Adhesion to a roll before and after addition of a vulcanization accelerator and a crosslinking agent was evaluated. ⊚ indicates no adhesion, ○ indicates almost no adhesion, and Δ indicates slightly adhesion. Extrusion characteristics: Extrusion characteristics, die swell and surface smoothness were evaluated. Here, the extrusion property is a degree of extrusion length per unit time by a Gerbe die extrusion test. The die swell is calculated by the following formula. Die swell (%) = [(cross-sectional area of extruded sample / die area) -1] × 100 Furthermore, the surface smoothness is the degree of smoothness of the surface of the extruded sample. Yes, Δ indicates that it is slightly rough.

Properties of Crosslinked Material A rubber sheet or block was prepared from a composition containing an acrylic copolymer rubber, and was crosslinked for a predetermined time using a crosslinking press machine. If necessary, a gear oven was used for further crosslinking for a predetermined time. The obtained crosslinked sheet or block is molded with a dumbbell cutter, and JIS K6
According to No. 301, cold resistance, heat resistance and oil resistance were measured. Here, the cold resistance was measured by impact embrittlement test Tb (° C.) and low temperature compression set [−30 ° C. × 24 hours, CS (%)]. The heat resistance was measured by measuring the change in hardness after deterioration by heating in air at 175 ° C. for 168 hours. Furthermore, the oil resistance is J
IS # 3 oil, ΔV after immersion at 150 ° C for 70 hours
(%) Is measured.

Examples 1 to 5, Comparative Examples 1 to 4 100 parts of monomer mixture, 4 parts of sodium lauryl sulfate,
0.25 part of p-menthane hydroperoxide, 0.01 part of ferrous sulfate, 0.025 part of sodium ethylenediaminetetraacetate and 0.04 part of sodium formaldehyde sulfoxylate were charged into a nitrogen-substituted autoclave at a reaction temperature. The reaction was carried out at 30 ° C. until the conversion of the monomer reached 90%, and 0.5 part of N, N-diethylhydroxylamine was added to stop the reaction. Next, the reaction product was taken out and steam was blown into it to remove unreacted monomers. The rubber latex thus obtained was added to 0.25
% Calcium chloride aqueous solution for coagulation, the coagulated product was thoroughly washed with water and dried at about 90 ° C. for 3 hours to obtain a copolymer A corresponding to Example 1. The composition of the copolymer A is ¹³ C-
It was calculated from the chemical shift of the NMR spectrum. However,
The chlorovinyl acetate content was determined by the fluorescent X-ray method, and glycidyl methacrylate was determined by the quantitative determination of epoxy groups, and the results are shown in Table 1. Copolymer rubbers B to I were similarly prepared.

Next, 60 parts of FEF carbon black and 1 part of stearic acid were added to 100 parts of each copolymer rubber obtained, and the mixture was kneaded with a Banbury mixer having an internal volume of 1.7 liters. The vulcanization accelerators and cross-linking agents shown in Tables 2 to 3 were added according to the type of cross-linkable monomer used in the production of the integrated rubber, and the mixture was mixed with a roll, and then the extrusion characteristics were evaluated. In addition, some samples at 170 ℃ for 20 minutes,
Crosslinked to produce a crosslinked sheet and block. The crosslinked sheet and block were placed in an oven at 175 ° C for 4 hours.
Further cross-linked for time. The obtained crosslinked sample is J
Tensile strength characteristics, cold resistance and oil resistance were measured according to IS K6301. The results are shown in Tables 2-3.

From the results shown in Table 2, a rubber composition using the acrylic copolymer rubber of the present invention is disclosed in JP-A-3-16000.
It has a good balance of heat resistance, cold resistance, and oil resistance as proposed in Japanese Patent Publication No. 8, while maintaining the performance of being excellent in compression set characteristics of low temperature property, while having good processability, particularly It can be seen that it has kneading processability, roll processability, and extrusion properties. On the other hand, as is clear from Table 3,
Comparative Examples 1 to 3 are inferior to Examples 1 to 3 in kneading processability, roll processability, and extrusion properties. Further, as in Comparative Example 4, when the polyene monomer is used in excess, it becomes difficult to disperse the carbon black itself.

[0033]

[Table 1] * 1) CH ₂ = CHCOO (C ₅ H ₁₀ COO) _n C ₂ H
₅ [n = 2 (average)], * 2) pentaerythritol triacrylate, * 3) ethylene glycol dimethacrylate, * 4) methyl ethyl ketone solvent, * 5) measurement not possible

[0034]

[Table 2] * 1) 30 rpm, L / D = 12, head temperature = 90 ° C, inlet temperature = 60 ° C, * 2) Crosslinking conditions; primary vulcanization (press) 170 ° C
× 20 minutes, secondary vulcanization (oven) 175 ℃ × 4 hours

[0035]

[Table 3] * 1) The evaluation was stopped because it was not dispersed in carbon black.

[0036]

The acrylic copolymer rubber obtained by the present invention has tensile strength, heat resistance, cold resistance (especially compression set characteristics at low temperature), oil resistance, and good kneading processability. It has roll processability and extrusion properties. Taking advantage of these properties, the acrylic copolymer rubber obtained by the present invention is various industrial materials such as bearing seals,
In addition to various sealing materials such as oil seals, packings, gaskets and O-rings, it can be used for belts, hoses, rolls, rubberized cloth, rubber gloves, additives for synthetic resins, adhesives, etc.

[Brief description of drawings]

FIG. 1 is a graph showing changes over time in the temperature and stirring power of a kneaded product in a Banbury mixer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Nobu 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. (A) General formula (I) (In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 3 to 20 carbon atoms, R ³ is a hydrocarbon group having 1 to 20 carbon atoms or a derivative thereof, and l is an integer of 1 to 20. )
A (meth) acrylic acid ester represented by: (B) general formula (II) (Wherein R ⁴ represents a hydrocarbon group having 1 to 10 carbon atoms) and / or an alkyl acrylate represented by the general formula (III) (In the formula, R ⁵ represents a hydrocarbon group having 2 to 10 carbon atoms, and R ⁶ represents a hydrocarbon group having 1 to 10 carbon atoms), an acrylic acid alkoxy-substituted alkyl ester represented by the formula (C) chlorine-based and / Alternatively, an epoxy-based crosslinkable monomer, a (D) polyene monomer, and (E) an unsaturated monomer copolymerizable with the components (A) to (D) are polymerized using a radical polymerization initiator. (A) component 3 to 30% by weight, (B)
Component 50 to 95% by weight, component (C) 0.1 to 10% by weight, component (D) 0.01 to 5% by weight, component (E) 0 to 3
0 wt% [(A) + (B) + (C) + (D) +
(E) = 100% by weight] for producing an acrylic copolymer rubber having a polymerization composition.