JPH09278943A - Rubber composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber composite capable of providing cross-linked rubber excellent in heat resistance, low-temperature characteristics and compression characteristics by sufficiently homogenizing a fluorine rubber with an acrylic rubber in micro state. SOLUTION: This rubber composite is composed of (A) 20-70wt.% fluorine rubber having polymerization unit derived from at least tetrafluoroethylene and propylene and (B) 80-30wt.% acrylic rubber in which a cross-linking point selected from epoxy group and vinyl group is introduced, and fluorine rubber particles are dispersed in the acrylic rubber and the average particle diameter of the fluorine rubber is 20-600nm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rubber composite in which a fluororubber and an acrylic rubber are composited, and more specifically, a rubber composite capable of obtaining a crosslinked rubber excellent in heat resistance, low temperature characteristics and compression characteristics. Regarding the body

[0002]

Acrylic rubber is a rubber material having heat resistance, oil resistance, and weather resistance, and is widely used as a rubber component for automobiles. However, along with the recent advancement in the functionality of automobiles, further improvements in various properties such as heat resistance have been demanded for acrylic rubbers constituting rubber parts for automobiles.

In order to meet these demands, it has been studied to make a composite with fluororubber, which is a rubber material having excellent heat resistance and chemical resistance. Specifically, a technique of blending acrylic rubber and fluororubber by mechanically kneading them together with a vulcanizing agent (JP-A-55-55).
No. 23128, JP-A-6-298899), the affinity between the acrylic rubber and the fluororubber is improved by introducing a monomer having a high affinity for the fluororubber as a monomer constituting the acrylic rubber. Techniques for enhancing (see JP-A-4-100846 and JP-A-7-26098), and dissolving / swelling a fluororubber in a monomer constituting an acrylic rubber, and then polymerizing the monomer (increase in molecular weight) By doing so, a technique for homogenizing the fluororubber and the acrylic rubber (Japanese Patent Laid-Open No. 4-363352, Japanese Patent Laid-Open No. 5-363352)
No. 98116) is disclosed.

[0004]

However, even with the above technique, it is extremely difficult to compound the acrylic rubber and the fluororubber having a small chemical affinity with each other.
That is, the above techniques (1) to (4) cannot obtain a sufficiently homogenized mixture in the micro state. Further, the above technique is not suitable for industrial production because it is difficult to dissolve / disperse the fluororubber in the monomer constituting the acrylic rubber.

The present invention has been made based on the above circumstances. An object of the present invention is to obtain a crosslinked rubber which is a composite in which fluororubber and acrylic rubber are sufficiently homogenized in a micro state, and which is excellent in heat resistance, low temperature characteristics (cold resistance) and compression characteristics. To provide a rubber composite.

[0006]

The rubber composite of the present invention comprises:
[A] Fluorine rubber 20 to 70 having at least polymerized units derived from tetrafluoroethylene and propylene
%, And 30 to 80% by weight of an acrylic rubber introduced with a cross-linking point selected from [B] epoxy group and vinyl group, wherein the particles of the fluororubber are dispersedly contained in the acrylic rubber, and an average particle thereof is contained. The diameter is 20 to 600 nm.

In the rubber composite of the present invention, (1) it is obtained by polymerizing (for example, graft polymerization) a monomer constituting acrylic rubber in the presence of fluororubber, and (2) fluororubber latex Obtained by mixing and dispersing acrylic rubber latex,
(3) The fluororubber constituting the rubber composite (fluororubber having polymerized units derived from tetrafluoroethylene and propylene) further has polymerized units derived from vinylidene fluoride, (4) constituting the rubber composite The fluororubber has a polymerized unit derived from a copolymerizable monomer capable of introducing a crosslinking point in a proportion of 0.1 to 10% by weight, (5) the acrylic rubber constituting the rubber composite, 0.1-10 wt% of polymerized units derived from a monomer capable of introducing a crosslinking point (epoxy group-containing monomer and monomer having two or more unsaturated double bonds in the molecule) It is preferable to have a ratio.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

<[A] Fluororubber> The fluororubber constituting the rubber composite of the present invention is a copolymer having at least polymerized units derived from tetrafluoroethylene and propylene. Specific examples of such fluororubber include tetrafluoroethylene / propylene copolymer, tetrafluoroethylene / propylene / vinylidene fluoride copolymer, tetrafluoroethylene / propylene / pentafluoropropylene copolymer, tetrafluoroethylene / propylene /
Trifluoroethylene copolymer, tetrafluoroethylene / propylene / chlorotrifluoroethylene copolymer, tetrafluoroethylene / propylene / perfluoromethyl vinyl ether copolymer, tetrafluoroethylene / propylene / perfluorohexyl vinyl ether copolymer, etc. Can be mentioned. Of these,
Tetrafluoroethylene / propylene copolymer and tetrafluoroethylene / propylene / vinylidene fluoride copolymer are preferred.

Further, from the viewpoint of improving the physical properties of the crosslinked rubber, the fluororubber constituting the rubber composite of the present invention contains a polymerized unit derived from a copolymerizable monomer capable of introducing a crosslinking point. It is preferable to have. Specific examples of such a copolymerizable monomer include glycidyl vinyl ether,
Examples thereof include allyl glycidyl ether, 2-chloroethyl vinyl ether, vinyl chloroacetate, allyl chloroacetate, 2-chloroethyl acrylate, vinyl acrylate, vinyl methacrylate and allyl methacrylate. Of these, glycidyl vinyl ether, 2-chloroethyl vinyl ether and vinyl acrylate are preferable. The proportion of polymerized units derived from the monomer in the fluororubber is preferably 0 to 10% by weight, more preferably 0 to 8% by weight. If this proportion exceeds 10% by weight, the original properties of the fluororubber may be impaired.

<[B] Acrylic rubber> The acrylic rubber constituting the rubber composite of the present invention is an acrylic rubber having a crosslinking point selected from an epoxy group and a vinyl group (unsaturated double bond) introduced therein. Such an acrylic rubber comprises a monomer component (a) composed of an acrylic acid alkyl ester and / or an acrylic acid alkoxyalkyl ester, an epoxy group-containing monomer, and two or more unsaturated double bonds in the molecule. It is prepared by copolymerizing a monomer mixture containing a crosslinking monomer component (b) selected from the contained monomers and another monomer component (c) copolymerizable therewith. be able to.

Examples of the alkyl acrylate ester as the monomer component (a) include those having an alkyl group having 1 to 8 carbon atoms such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and octyl acrylate. be able to. Of these, ethyl acrylate and n-butyl acrylate are preferred.

As the acrylic acid alkoxyalkyl ester which is the monomer component (a), methoxymethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, methoxyethoxyethyl acrylate and the like have 1 to 4 carbon atoms. The thing which has an alkyl group and an alkylene group can be mentioned. Of these, methoxyethyl acrylate is preferred.

Monomer component (a) in the monomer mixture
The content ratio of is usually 99.9 to 80% by weight, preferably 99.5 to 86% by weight.

The monomer component (b) is a crosslinking monomer for introducing a crosslinking point (epoxy group or vinyl group) into the resulting acrylic rubber. When the introduced crosslinking point is an epoxy group and / or a vinyl group, co-crosslinking with fluororubber becomes easy, and a crosslinked rubber excellent in heat resistance, compression characteristics and low temperature characteristics can be obtained.

Examples of the epoxy group-containing monomer for introducing an epoxy group into acrylic rubber include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, and methacryl glycidyl ether. Of these, glycidyl methacrylate and allyl glycidyl ether are preferred.

Examples of the monomer used for introducing a vinyl group into the acrylic rubber and having two or more unsaturated double bonds in the molecule include, for example, vinyl methacrylate, vinyl acrylate, allyl methacrylate and cidiclopentenyl. Oxyethyl acrylate, 1,1-dimethylpropenyl methacrylate, 1,1-dimethylpropenyl acrylate, 1,1-dimethyl-3-butenyl methacrylate, 1,1-dimethyl-3-butenyl acrylate, divinyl itaconate, maleic acid Divinyl, vinyl 1,1-dimethylpropenyl ether, vinyl 1,1
-Dimethyl-3-butenyl ether, 1-acryloyloxy-1-phenylethene and the like can be mentioned. Of these, vinyl methacrylate, allyl methacrylate and dicyclopentenyloxyethyl acrylate are preferred.

Monomer component (b) in the monomer mixture
The content ratio of is usually 0.1 to 10% by weight, preferably 0.5 to 8% by weight. If the proportion of the monomer component (b) for crosslinking is less than 0.1% by weight, the crosslinking density will be too small to obtain a crosslinked rubber having good physical properties. On the other hand, when this proportion exceeds 10% by weight, the rubber composition containing the obtained rubber composite tends to scorch, which is not preferable from the viewpoint of storage stability.

The monomer component (c) is not particularly limited as long as it is another monomer copolymerizable with the above-mentioned monomer components (a) and (b). For example, trifluoroethyl acrylate. , Pentafluoroethyl acrylate, perfluoroalkyl acrylate, vinyl acetate,
Examples thereof include vinyl caproate, acrylonitrile, α-methylacrylonitrile, styrene, ethylene, vinyl chloride and vinylidene chloride. Of these,
Acrylonitrile and α-methylacrylonitrile are preferred.

Monomer component (c) in the monomer mixture
The content ratio of is usually 0 to 10% by weight, preferably 0 to 8% by weight.

<Content ratio of fluororubber and acrylic rubber>
Regarding the content ratio of the fluororubber and the acrylic rubber constituting the rubber composite of the present invention, "fluororubber: acrylic rubber (weight ratio)" is usually 20:80 to 70:30,
Preferably 30:70 to 60:40, more preferably 3
It is 5:65 to 55:45. If the proportion of the fluororubber is too small, the resulting crosslinked rubber cannot fully exhibit the effect of improving the properties such as heat resistance. On the other hand, if the proportion of fluororubber is too high, the uniform dispersibility of the fluororubber particles in the acrylic rubber will decrease, and a crosslinked rubber that is practically satisfactory cannot be obtained.

<Dispersion Particle Diameter of Fluoro Rubber> The rubber composite of the present invention is constituted by acryl rubber particles containing fluoro rubber dispersed therein. Here, the average particle diameter of the fluororubber is usually 20 to 600 nm, and preferably 50.
˜500 nm, more preferably 60 to 400 nm. It is difficult to prepare fluororubber particles having an average particle size of less than 20 nm. On the other hand, if the average particle diameter of the fluororubber exceeds 600 nm, the fluororubber in the rubber composite becomes a continuous phase, and the heat resistance, low temperature characteristics and compression characteristics of the resulting crosslinked rubber are deteriorated, which is not preferable.

<Method for producing rubber composite> As a method for producing the rubber composite of the present invention, (1) a monomer (the above-mentioned monomer mixture) which constitutes acrylic rubber is added to fluororubber latex. A method in which the monomer is polymerized in the presence of fluororubber and then coagulated according to a conventional method (hereinafter referred to as "graft polymerization method"), and (2) a fluororubber latex and an acrylic rubber latex are mixed and dispersed, Then, a method of coagulating according to a conventional method (hereinafter referred to as "latex mixing method") can be mentioned.

The average particle size of the fluororubber particles dispersed in the acrylic rubber can be controlled by adjusting the latex particle size of the fluororubber latex used for producing the rubber composite. .

<Preparation and Crosslinking of Rubber Composition> The rubber composite of the present invention can be suitably used as a raw material rubber constituting a rubber composition. Examples of the compounding agent for rubber used with the rubber composite of the present invention include cross-linking agents, cross-linking aids, cross-linking retarders, reinforcing agents, fillers, antioxidants, stabilizers, plasticizers, lubricants and processing aids. And so on.

The above rubber composition is obtained by mixing the rubber composite of the present invention with a compounding agent for rubber to obtain a rubber compound. The rubber compound is used in a Banbury type mixer, a pressure kneader, an open roll, etc. Can be prepared by kneading. By crosslinking the rubber composition thus prepared, a crosslinked rubber excellent in heat resistance, low temperature characteristics and compression characteristics can be obtained. As a method for crosslinking the rubber composition containing the rubber composite of the present invention, press vulcanization applied to ordinary rubber compositions, injection molding vulcanization,
Hot air vulcanization, steam vulcanization, etc. can be adopted. If one example of the crosslinking method (condition) is shown, it is 150 to 180 ° C., and
Examples thereof include a method in which primary crosslinking is performed for a certain period of time under heating / pressurization of 0 to 150 kg / cm ² , and then secondary crosslinking is performed under heating / normal pressure of 150 to 230 ° C. The crosslinked rubber obtained as described above is a roll,
It is suitable as various industrial rubber products that require higher characteristics, including automotive parts such as seals, gaskets, packings, O-rings, oil seals, hoses, and diaphragms.

[0026]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, "part" means "part by weight".

<Production of Rubber Composite> [Example 1] A monomer mixture (60% by weight of tetrafluoroethylene, 15% by weight of propylene, 25% by weight of vinylidene fluoride) constituting a fluororubber is copolymerized by a conventional method. As a result, fluororubber latex (average particle diameter of latex particles: 200 nm) was obtained. 1250 g of the obtained fluororubber latex (content of fluororubber: 37
5 g) was put into a glass separable flask (volume: 2 liters) purged with nitrogen, and then 10 g of sodium lauryl sulfate dissolved in distilled water and a monomer mixture (52% by weight of ethyl acrylate) constituting acrylic rubber. ，
Butyl acrylate 30% by weight, methoxyethyl acrylate 15% by weight, allyl glycidyl ether 3% by weight)
375 g was added and emulsified. The reaction mixture is mixed with 80
The temperature was raised to ℃, and 0.25 g of benzoyl peroxide,
Polymerization was initiated by adding 0.01 g of ferrous sulfate, 0.025 g of sodium ethylenediaminetetraacetate, and 0.04 g of sodium formaldehyde sulfoxylate.
When the polymerization conversion rate reached 95%, 0.5 g of N, N-diethylhydroxyamine was added to terminate the polymerization reaction. Then, the reaction product was taken out from the separable flask, and unreacted monomers were removed by blowing steam to obtain a graft polymerization latex. The graft-polymerized latex thus obtained was added to a 0.25% calcium chloride aqueous solution to coagulate, the coagulated product was thoroughly washed with water and dried at about 90 ° C. for 3 hours, and further using a 6-inch test roll. The rubber composite (G-1) of the present invention was produced by carrying out mastication for 3 minutes. This rubber composite (G-1) is press-molded to produce a test piece,
Observation with a transmission electron microscope (TEM) confirmed that the fluororubber particles were uniformly dispersed. Average particle size of fluororubber particles (10 measured arbitrarily
The average value of the particle diameters of individual particles was 220 nm.

Example 2 The rubber composite (G-2 of the present invention was prepared in the same manner as in Example 1 except that the composition of the monomer mixture constituting the fluororubber was changed according to the formulation shown in Table 1 below. ) Was manufactured. Obtained rubber composite (G-2)
For a test piece prepared in the same manner as in Example 1 was observed with a transmission electron microscope, and it was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 185 nm.

Example 3 In the same manner as in Example 1 except that the compositions of the monomer mixture forming the fluororubber and the monomer mixture forming the acrylic rubber were changed according to the formulation shown in Table 1 below. Rubber composite (G-3) of the present invention
Was manufactured. Regarding the obtained rubber composite (G-3),
When a test piece prepared in the same manner as in Example 1 was observed with a transmission electron microscope, it was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 180 nm.

Example 4 The rubber composite of the present invention (G-4) was prepared in the same manner as in Example 1 except that the composition of the monomer mixture constituting the fluororubber was changed according to the formulation shown in Table 1 below. ) Was manufactured. Obtained rubber composite (G-4)
For a test piece prepared in the same manner as in Example 1 was observed with a transmission electron microscope, and it was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 150 nm.

Example 5 According to the formulation shown in Table 1 below, the weight ratio of fluororubber to acrylic rubber was 60:40.
A rubber composite (G-5) of the present invention was produced in the same manner as in Example 1 except that the above was changed to. With respect to the obtained rubber composite (G-5), a test piece produced in the same manner as in Example 1 was observed with a transmission electron microscope.
It was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 380 nm.

Example 6 According to the formulation shown in Table 1 below, the weight ratio of fluororubber to acrylic rubber was 30:70.
A rubber composite (G-6) of the present invention was produced in the same manner as in Example 1 except that the above was changed to. With respect to the obtained rubber composite (G-6), a test piece produced in the same manner as in Example 1 was observed with a transmission electron microscope.
It was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 195 nm.

[Example 7] A fluororubber latex (60% by weight of tetrafluoroethylene, 15% by weight of propylene, 25% by weight of vinylidene fluoride) constituting a fluororubber was copolymerized by a conventional method to give a fluororubber latex ( The average particle diameter of the latex particles was 450 nm). Acrylic rubber latex was prepared by copolymerizing a monomer mixture constituting the acrylic rubber (52% by weight of ethyl acrylate, 30% by weight of butyl acrylate, 15% by weight of methoxyethyl acrylate, 3% by weight of allyl glycidyl ether) according to a conventional method. Obtained. The fluororubber latex and the acrylic rubber latex obtained as described above were mixed in a weight ratio of fluororubber and acrylic rubber of 50: 5.
It was mixed and dispersed so as to be 0, and then a mixed and dispersed latex was obtained. The mixed and dispersed latex thus obtained was coagulated, washed with water, dried and masticated in the same manner as in Example 1 to produce the rubber composite (M-1) of the present invention. Regarding the obtained rubber composite (M-1), Example 1
When a test piece manufactured in the same manner as in (1) was observed with a transmission electron microscope, it was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 450 nm.

[Example 8] A fluororubber latex ( The average particle diameter of the latex particles was 80 nm). A rubber composite (M-2) of the present invention was produced in the same manner as in Example 7 except that the fluororubber latex obtained as described above was used. Obtained rubber composite (M-2)
For a test piece prepared in the same manner as in Example 1 was observed with a transmission electron microscope, and it was confirmed that the fluororubber particles were uniformly dispersed. The average particle size of the fluororubber particles was 80 nm.

[0035]

[Table 1]

[Comparative Example 1] A fluororubber latex (copolymerized with a monomer mixture (60% by weight of tetrafluoroethylene, 15% by weight of propylene, 25% by weight of vinylidene fluoride) constituting the fluororubber according to a conventional method The average particle size of the latex particles was 680 nm). A rubber composite for comparison (M-3) was produced in the same manner as in Example 7 except that the fluororubber latex obtained as described above was used. Obtained rubber composite (M-3)
For a test piece prepared in the same manner as in Example 1, the piece was observed with a transmission electron microscope. As a result, fluororubber was present as a continuous phase, and the average particle size was 680.
It was as large as nm.

Comparative Example 2 According to the formulation shown in Table 2 below, the weight ratio of fluororubber to acrylic rubber was 80:20.
A rubber composite (M-4) for comparison was produced in the same manner as in Example 7 except that the above was changed to. With respect to the obtained rubber composite (M-4), a test piece produced in the same manner as in Example 1 was observed with a transmission electron microscope.
Fluorine rubber was present as a continuous phase, and the particle size could not be measured.

Comparative Example 3 According to the formulation shown in Table 2 below, the weight ratio of fluororubber and acrylic rubber was 10:90.
A rubber composite for comparison (M-5) was produced in the same manner as in Example 7 except that the above was changed to. With respect to the obtained rubber composite (M-5), a test piece produced in the same manner as in Example 1 was observed with a transmission electron microscope.
It was confirmed that the fluororubber particles were uniformly dispersed, and the average particle size was 210 nm.

[Comparative Example 4] Each of the fluororubber latex and the acrylic rubber latex obtained in the same manner as in Example 7 was coagulated, washed with water and dried to obtain a fluororubber and an acrylic rubber. The resulting fluororubber and acrylic rubber were kneaded using a 6-inch test roll to prepare a comparative rubber composite (M-6).
With respect to the obtained rubber composite (M-6), a test piece prepared in the same manner as in Example 1 was observed with a transmission electron microscope. As a result, fluororubber and acrylic rubber were dispersed unevenly, and the particle size was Could not be measured.

[0040]

[Table 2]

Comparative Example 5 Same as Example 1 except that 3% by weight of hydroxystyrene was used in place of allyl glycidyl ether to introduce a crosslinkable hydroxyl group into the acrylic rubber according to the formulation shown in Table 3 below. Then, a rubber composite (G-7) for comparison was produced. With respect to the obtained rubber composite (G-7), a test piece produced in the same manner as in Example 1 was observed with a transmission electron microscope. As a result, it was confirmed that the fluororubber particles were uniformly dispersed. The average particle diameter was 210 nm.

Comparative Example 6 Same as Example 1 except that active chlorine was introduced into the acrylic rubber by using 3% by weight of chloromethylstyrene instead of allyl glycidyl ether according to the formulation shown in Table 3 below. Then, a rubber composite (G-8) for comparison was produced. With respect to the obtained rubber composite (G-8), a test piece produced in the same manner as in Example 1 was observed with a transmission electron microscope. As a result, it was confirmed that the fluororubber particles were uniformly dispersed. The average particle diameter was 220 nm.

[0043]

[Table 3]

<Preparation of Rubber Composition> [Preparation Example 1] 100 parts of the rubber composite (G-1) obtained in Example 1 above, 1.0 part of stearic acid, and MT.
15.0 parts of carbon black, 10.0 parts of wet silica "Nipseal ER" (manufactured by Nippon Silica Co., Ltd.), 1.0 part of diphenylamine derivative "Now Guard 445" (manufactured by Uniroyal Co.), and magnesium oxide "Kyowamag # 3"
0 "(manufactured by Kyowa Chemical Industry Co., Ltd.), 3.0 parts of calcium hydroxide" Carbit "(manufactured by Omi Chemical Co., Ltd.), 1.0 part of tetrabutylammonium bromide, and hexamethylenediaminecarbamate" Diak No. " 1 "(manufactured by DuPont) and kneaded with a 6-inch test roll to prepare a rubber composition containing the rubber composite of the present invention.

[Preparation Example 2] Instead of the rubber composite (G-1), the rubber composite (G-2) obtained in the above Example 2 was used.
Similar to Preparation Example 1 except that 100 parts were used,
A rubber composition containing the rubber composite of the present invention was prepared.

[Preparation Example 3] 100 parts of the rubber composite (G-3) obtained in Example 3 above and 1.0 part of stearic acid.
Parts, MT carbon black 15.0 parts, wet silica “Nipseal ER” (manufactured by Nihon Silica Co., Ltd.) 10.0 parts, diphenylamine derivative “Now Guard 445” (manufactured by Uniroyal Co.) 1.0 part, and magnesium oxide "Kyowamag # 30" (Kyowa Chemical Industry Co., Ltd.) 5.0 parts and calcium hydroxide "Carbit" (Omi Chemical Co., Ltd.) 3.0
Parts, 1.0 part of tetrabutylammonium bromide, 3.0 parts of triallyl isocyanurate "TAIQ" (manufactured by Nippon Kasei Co., Ltd.), 1,3-bis (t-butylperoxy-isopropyl) benzene "Perkadox 14". "
A rubber composition containing the rubber composite of the present invention was prepared by kneading a mixture of 1.0 part (manufactured by Kayaku Akzo Co., Ltd.) using a 6-inch test roll.

Preparation Examples 4 to 8 Instead of the rubber composite (G-1), the rubber composites (G-4) to (G-6) and the rubber composites obtained in the above Examples 4 to 8 were obtained. (M-1) ~
A rubber composition containing the rubber composite of the present invention was prepared in the same manner as in Preparation Example 1 except that 100 parts of each of (M-2) was used.

[Comparative Preparation Examples 1 to 4] Rubber composite (G-
Comparative Example 1 was prepared in the same manner as in Preparation Example 1 except that 100 parts of each of the rubber composites (M-3) to (M-6) obtained in Comparative Examples 1 to 4 were used instead of 1). A rubber composition containing the rubber composite of was prepared.

Comparative Preparation Example 5 100 parts of the rubber composite (G-7) obtained in Comparative Example 5 above, 1.0 part of stearic acid, 15.0 parts of MT carbon black, and wet silica “nip seal”. ER "(manufactured by Nippon Silica) 10.
0 parts and diphenylamine derivative "Naugard 445"
1.0 part (manufactured by Uniroyal), 5.0 parts magnesium oxide "Kyowamag # 30" (manufactured by Kyowa Chemical Industry Co., Ltd.), and calcium hydroxide "Carbit" (manufactured by Omi Chemical Co., Ltd.)
3.0 parts and tetrabutylammonium bromide 1.
A rubber composition containing a rubber composite for comparison was prepared by kneading a compound consisting of 0 part with a 6-inch test roll.

Comparative Preparation Example 6 100 parts of the rubber composite (G-8) obtained in Comparative Example 6 above, 1.0 part of stearic acid, 15.0 parts of MT carbon black, and wet silica “nip seal”. ER "(manufactured by Nippon Silica) 10.
0 parts and diphenylamine derivative "Naugard 445"
1.0 part (manufactured by Uniroyal), 5.0 parts magnesium oxide "Kyowamag # 30" (manufactured by Kyowa Chemical Industry Co., Ltd.), and calcium hydroxide "Carbit" (manufactured by Omi Chemical Co., Ltd.)
3.0 parts and tetrabutylammonium bromide 1.
0 part, powdered sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd.) 0.3 part, aliphatic monocarboxylate potassium "NONSAR SK-1" (manufactured by NOF CORPORATION), and aliphatic monocarboxylate sodium "Nonsar SN-1" (Nippon Yushi Co., Ltd.)
A rubber composition containing a comparative rubber composite was prepared by kneading a mixture of 0.3 part and a 6-inch test roll.

<Evaluation of Rubber Composition> With respect to each of the rubber compositions obtained by the above Preparation Examples and Comparative Preparation Examples,
According to the cross-linking conditions shown in Tables 4 to 5, primary cross-linking by hot pressing and secondary cross-linking by a gear oven were performed to prepare a test piece (cross-linked rubber) according to the following test method. For each of the obtained crosslinked rubbers, a normal state physical property test (JIS K6251 and JIS K625
3), air heating aging test (JIS K6257)
), Immersion test (according to JIS K6258), low temperature torsion test (according to JIS K6261)
And compression set test (according to JIS K6262)
Was done. The evaluation results are also shown in Tables 4 to 5.

[0052]

[Table 4]

[0053]

[Table 5]

As is clear from the above evaluation results, the compositions according to Preparation Example 1 and Preparation Examples 5 to 6 are obtained even if the rubber compositions have the same kinds and proportions of the monomers constituting the rubber composite. Comparative Preparation Example 1 in which the dispersed particle size of fluororubber is excessive
A crosslinked rubber which is more excellent in heat aging resistance, low temperature characteristics and compression characteristics than the composition according to Comparative Preparation Example 4 containing the rubber composite obtained by kneading the composition according to Example 1 and fluororubber and acrylic rubber is obtained. be able to. Further, the composition according to Preparation Example 5 containing the rubber composite (G-5) in which the proportion of the fluororubber is 60% by weight contains the rubber composite (M-4) in which the proportion is 80% by weight. It is possible to obtain a crosslinked rubber that is more excellent in heat aging resistance and low temperature properties than the composition according to Comparative Preparation Example 2 described above. Furthermore, the ratio of fluororubber is 30
Preparation Example 6 containing the rubber composite (G-6) in an amount of wt%
The composition according to (1) has a heat aging resistance, compression characteristics and chemical resistance (oil resistance) that is higher than that of the composition according to Comparative Preparation Example 3 containing the rubber composite (M-5) in which the proportion is 10% by weight. An excellent crosslinked rubber can be obtained. Furthermore, the composition containing the rubber composite of the present invention in which an epoxy group or a vinyl group is introduced as a cross-linking point of acrylic rubber is a comparative preparation example containing a rubber composite (G-7) in which a hydroxyl group is introduced. 5 composition, rubber complex into which active chlorine is introduced (G-
It is possible to obtain a crosslinked rubber which is more excellent in normal state physical properties, heat aging resistance, low temperature characteristics and compression characteristics than the composition of Comparative Preparation Example 6 containing 8).

[0055]

Since the rubber composite of the present invention is a composite in which fluororubber and acrylic rubber are sufficiently homogenized in a micro state, they are excellent in various characteristics such as heat resistance, low temperature characteristics and compression characteristics. A crosslinked rubber can be obtained.

Claims (1)

[Claims] 1. [A] 20 to 70% by weight of a fluororubber having polymerized units derived from at least tetrafluoroethylene and propylene, and [B] an acrylic rubber 30 having a crosslinking point selected from an epoxy group and a vinyl group.
To 80% by weight, the particles of the fluororubber are dispersed and contained in the acrylic rubber, and the average particle diameter thereof is 20 to 600 nm.