JPH11343378A - Rubber composition for oil resistant hose, and oil-resistant hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber compsn. which gives a steam-vulcanized article exhibiting a small decrease in strength after thermal loading and having improved pressure resistance retention and oil resistance by compounding an acrylic rubber obtd. by the copolymn. of an alkyl acrylate, a fumaric acid monoester, or the like, with a vulcanizing agent. SOLUTION: An acrylic rubber having a Mooney viscosity (ML1+4 , 100 deg.C) of 1-150, pref. 15-100, and a carboxy-functional group content of 0.0005-0.06 mol/100 g acrylic rubber, pref. 0.003-0.020 mol/100 g acrylic rubber, is obtd. by the copolymn. of 10-99.9 wt.%, pref. 50-97.8 wt.%, alkyl acrylate, 0.1-40 wt.%, pref. 0.2-20 wt.%, fumaric acid monoester, 0-50 wt.%, pref., 2-30 wt.%, alkoxyalkyl acrylate, and if necessary, 0-30 wt.% monomer copolymerizable with the foregoing monomers. 100 pts.wt. acrylic rubber above-obtd. is compounded with 0.1-10 pts.wt., pref. 0.2-5 pts.wt., vulcanizing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition for producing an oil-resistant hose, and more particularly, to a rubber for producing an oil-resistant hose using an acrylic rubber copolymerized with a fumaric acid monoester as a carboxyl group-containing monomer. Composition.

[0002]

2. Description of the Related Art Oil-resistant hoses are generally manufactured by using an acrylate copolymer rubber such as an epoxy group-containing acrylic rubber or an ethylene-acrylate copolymer rubber as a raw rubber, forming the hose into a shape, and then steam vulcanizing. When a rubber composition containing an epoxy group-containing acrylic rubber is used to produce a hose by steam vulcanization after molding, there is a problem that the vulcanization properties are lower than when press vulcanizing the same rubber composition. On the other hand, a composition containing an ethylene-acrylate copolymer rubber as a main component has a problem in that it is strongly adhered when extruded into a hose and hinders handling of the molded article.

In order to solve such a problem, Japanese Patent Application Laid-Open No. 6-99515 discloses an oil-resistant hose made of an acrylic rubber obtained by copolymerizing a monoalkyl maleate as a carboxyl group-containing monomer as a raw rubber. I have.
In this hose, the vulcanization properties are reduced by steam vulcanization, and the adhesiveness during extrusion molding is improved.

[0004]

However, a hose made of an acrylic rubber copolymerized with a monoalkyl maleate as a raw rubber has a high pressure resistance, particularly a pressure resistance after a heat load (after receiving a heat history). There was a problem of shortage. An object of the present invention is to provide a rubber composition for producing an oil-resistant hose, in which a steam vulcanizate has the same vulcanizate properties as a press vulcanizate and has a small decrease in strength after heat load.

[0005] By the way, a butenedioic acid monoester such as a maleic acid monoalkyl ester and an acrylic acid alkyl ester or an acrylic rubber obtained by copolymerizing these with ethylene are known from JP-A-50-45031. It has been shown that vulcanizable compositions using acrylic rubber have good scorch properties. However, although this publication discloses the physical properties of a vulcanized product obtained by press-vulcanizing a vulcanizable composition, there is no disclosure suggesting the physical properties of a steam vulcanized product. Also, there is no description in JP-A-6-99515 mentioned above for predicting the physical properties of a steam vulcanizate of an acrylic rubber copolymerized with a butenedioic acid monoester other than a monoalkyl maleate.

The inventors of the present invention have studied to achieve the above object in consideration of these known techniques, and as a result, as a carboxyl group-containing monomer, fumaric acid monoester is used in a relatively large amount with alkyl acrylate. It has been found that the object can be achieved by using the obtained acrylic rubber which can be polymerized, and the present invention has been completed.

[0007]

According to the present invention, there is provided a rubber composition for an oil-resistant hose, comprising an acrylic rubber obtained by copolymerizing an alkyl acrylate and a monoester of fumaric acid, and a vulcanizing agent. And an oil-resistant hose obtained by molding and vulcanizing the composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to embodiments. The acrylic rubber used in the present invention is obtained by copolymerizing a monoester of fumaric acid and an alkyl acrylate, and a copolymer thereof with an alkoxyalkyl acrylate. Examples of the monoester of fumaric acid in the present invention include, for example, monomethyl fumarate, monoethyl fumarate, mono-n- or iso-propyl fumarate, mono-n- or iso- or ter-fumarate.
Butyl, mono-n-amyl fumarate, mono-n-hexyl fumarate, mono-n-heptyl fumarate, mono-n-fumarate
Monoalkyl esters of fumaric acid having about 1 to 10 carbon atoms in an alkyl group such as octyl and mono (2-ethylhexyl) fumarate; monomethoxymethyl fumarate, monomethoxyethyl fumarate, monoethoxyethyl fumarate, mono fumarate Monoalkoxyalkyl fumarate having an alkylene group having about 1 to 5 carbon atoms and an alkoxy group having about 1 to 5 carbon atoms, such as methoxybutyl. Among them, monomethyl fumarate, monoethyl fumarate, mono-n-propyl fumarate, mono-n-butyl fumarate, monomethoxymethyl fumarate, monomethoxyethyl fumarate and the like are preferable, and monoethyl fumarate and mono fumarate are more preferable. n-butyl and the like.

In the present invention, as the alkyl acrylate copolymerized with the fumaric acid monoester, any of those conventionally used in acrylic rubbers can be used and is not particularly limited. For example, acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid n- or iso-propyl ester, acrylic acid n- or iso- or ter-butyl ester, acrylic acid n-
Amyl ester, n-hexyl acrylate, n-heptyl acrylate, (2-ethylhexyl) acrylate, n-octyl acrylate, n-nonyl acrylate, n-decyl acrylate, acrylic acid 2 Acrylate alkyl esters having an alkyl group having about 1 to 10 carbon atoms, such as cyanoethyl; Among them, ethyl acrylate or n-butyl acrylate is preferred. These acrylic acid alkyl esters may be used alone or in combination.
More than one species can be used in combination.

As the alkoxyalkyl acrylate used together with the alkyl acrylate, any of those conventionally used in acrylic rubbers can be used and is not particularly limited. For example, alkylene groups having about 1 to 5 carbon atoms, such as methoxymethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, and 2-butoxyethyl acrylate; An alkoxyalkyl acrylate having an alkoxy group having about 1 to 5 carbon atoms is exemplified. Of these, acrylic acid 2-methoxyethyl ester and acrylic acid 2-ethoxyethyl ester are preferred. These acrylic acid alkoxyalkyl esters can be used alone or in combination of two or more.

In the present invention, if necessary, a monomer copolymerizable with the above-mentioned monomer can be used. Examples of such a monomer include unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile; Α-olefins such as propylene; aromatic vinyl compounds such as styrene and α-methylstyrene; vinyl monomers such as vinyl chloride, vinylidene chloride, vinyl acetate, ethyl vinyl ether and butyl vinyl ether; alkoxyalkyl methacrylate; Furfuryl acrylate,
Other derivatives of acrylic acid and methacrylic acid such as acrylamide; conjugated dienes such as isoprene, butadiene, chloroprene, and piperylene; non-conjugated dienes such as dicyclopentadiene, norbornene, ethylidene norbornene, hexadiene, norbornadiene; divinylbenzene, ethylene glycol Examples include polyfunctional compounds such as diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, and propylene glycol dimethacrylate. These can be used alone or in combination of two or more.

The acrylic rubber used in the present invention can be obtained by radical polymerization of the above-mentioned monomers in the same manner as ordinary polymerization of acrylic rubber. In the present invention, the polymerization form such as emulsion polymerization, solution polymerization, suspension polymerization, batch system, polymerization system such as continuous system, polymerization conditions such as polymerization temperature, recovery method and the like are not particularly limited, and any polymerization method It may be.

The ratio of each monomer in the monomer mixture used in producing the acrylic rubber used in the present invention is appropriately determined according to the properties required for a hose using the acrylic rubber, and is particularly limited. Not done. Usually, the fumaric acid monoester is 0.1 to 40% by weight, preferably 0.2 to 20% by weight,
More preferably, it is 0.5 to 10% by weight, and the alkyl acrylate is 10 to 99.9% by weight, preferably 50 to 97.8% by weight, and more preferably 70 to 94.5%.
% By weight, and the content of the alkoxyalkyl acrylate is 0 to 50% by weight, preferably 2 to 30% by weight, more preferably 5 to 20% by weight. If necessary, other monomers copolymerized with these monomers are contained in the monomer mixture at 0%.
It is used within a range that does not impair the inherent properties of the acrylic rubber of up to 30% by weight.

The acrylic rubber used in the present invention thus obtained has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of usually 1
It is about 0 to 150. Preferably it is 15-100, More preferably, it is 20-60. The amount of each monomer in the acrylic rubber coincides with the above-mentioned amount used (the amount charged during polymerization). The preferred amount of fumaric acid monoester in the acrylic rubber is 0.0005 to 0.06 mol, preferably 0.003 to 0.020 mol, in terms of the amount of carboxyl functional group (ephr) in 100 g of the acrylic rubber. Preferably it is 0.005 to 0.010 mol. 0.000
If it is less than 5 moles, vulcanization becomes insufficient and it is difficult to use as a vulcanized rubber. On the other hand, if it exceeds 0.06 mol, vulcanization becomes excessive, elongation is reduced, and strength and heat resistance are insufficient, which is not preferable.

The rubber composition for producing a hose of the present invention is obtained by blending a vulcanizing agent with the above acrylic rubber.
Incidentally, the term “vulcanization” is originally used when crosslinking is performed by using an unsaturated rubber such as a diene rubber or the like as a crosslinking agent by using sulfur or a sulfur-donating compound. Even when a rubber having no oxide or unsaturated bond is cross-linked by using a cross-linking agent specific to the rubber, these cross-linking agents are called vulcanizing agents, and the cross-linking is called vulcanization. Therefore, also in the present invention, a vulcanizing agent,
Crosslinking is called vulcanization.

In the present invention, any conventionally known vulcanizing agent used for vulcanizing a carboxyl group-containing acrylic rubber can be used, and is not particularly limited. Preferred vulcanizing agents include, for example, primary amines such as polyvalent aliphatic primary amines and polyvalent aromatic primary amines and derivatives thereof, and polyhydrazide group-containing compounds. As polyvalent aliphatic primary amines and derivatives thereof, for example,
Hexamethylene diamine, hexamethylene diamine carbamate, tetramethylene pentamine, hexamethylene diamine-cinnamaldehyde condensate, hexamethylene diamine-dibenzoate salt, and the like, and aromatic primary amines include, for example, 4,4 ′ -Methylene dianiline, 4,4'-diaminodiphenyl ether, m
-Phenylenediamine, p-phenylenediamine, 4,
4'-methylenebis (o-chloroaniline) and the like. Among them, hexamethylenediaminecarbamate, hexamethylenediamine-cinnamaldehyde condensate, 4,4'-methylenedianiline, and 4,4'-diaminodiphenylether are particularly preferred. These can be used alone or in combination of two or more.

Examples of the polyhydrazide group-containing compound include, for example, isophthalic dihydrazide, terephthalic dihydrazide, phthalic dihydrazide, 2,6-dinaphthalenedicarboxylic dihydrazide, oxalic dihydrazide, malonic dihydrazide, adipic dihydrazide, sebacic acid A reaction product of a carboxylic acid such as an aliphatic carboxylic acid or an aromatic carboxylic acid such as dihydrazide, maleic dihydrazide, or fumaric hydrazide with hydrazine is exemplified. These can be used alone or in combination of two or more.

Usually, a vulcanizing agent is often used together with a vulcanization accelerator, and the use of a vulcanization accelerator is also desirable in the present invention. Examples of the vulcanization accelerator include (1) alkali metal salts and alkali metal hydroxides of inorganic weak acids (for example, sodium hydroxide, sodium carbonate, potassium hydroxide, sodium hydrogen carbonate, etc.), and (2) organic weak acids. Alkali metal salts, alkali metal alcoholates and phenolates (eg, sodium stearate, potassium stearate, sodium laurate, sodium benzoate, sodium ethoxide, etc.), (3) quaternary ammonium salts and quaternary phosphonium salts , Hydroxide, alcoholate, phenolate and the like (tetrabutylammonium hydroxide, tetramethylammonium bromide, benzyltriphenylphosphonium chloride, tetrabutylammonium methoxide, octadecyltrimethylammonium bromide and the like), ( ) A tertiary amine (e.g., triethylenediamine, N, N, N ', N'-tetramethyl-1,4-butanediamine, N, N, N',
N'-tetramethyl-2,6-diaminophenol,
N, N-dimethylaminoethanol, etc.), (5) guanidines (diphenylguanidine, di-o-tolylguanidine, tetramethylguanidine, dibutylguanidine, etc.), (6) heterocyclic tertiary amines (imidazole, pyridine, Quinoline, etc.). These can be used alone or in combination of two or more.

Although the amount of the vulcanizing agent is not particularly limited,
Usually, the ratio is 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, per 100 parts by weight of the acrylic rubber. 0.
If the amount is less than 1 part by weight, it is difficult to obtain a vulcanizate having insufficient tensile strength and satisfactory tensile strength, while if it exceeds 10 parts by weight, the vulcanizate becomes too hard and the elongation is reduced. growing. The amount of the vulcanizing agent used is a general guideline, and the more accurate amount of the vulcanizing agent used is based on the acrylic rubber 100
The amount of the functional group in the vulcanizing agent per g is 0.0002 to 0.
1 mol, preferably 0.0015 to 0.035 mol, more preferably 0.002 to 0.02 mol. The amount of the vulcanization accelerator used is usually the same as the acrylic rubber 10 of the present invention.
0.1 to 20 parts by weight, preferably 0.2 to 0 parts by weight
The amount is 10 to 10 parts by weight, more preferably 0.4 to 5 parts by weight. At a use ratio of less than 0.1 part by weight, it is difficult to obtain a vulcanized product having insufficient tensile strength and satisfactory tensile strength.
On the other hand, if it exceeds 20 parts by weight, there is no effect corresponding to the use ratio in terms of vulcanization properties and it is uneconomical, and processing stability is undesirably lost.

The rubber composition for producing an oil-resistant hose of the present invention comprises the above-mentioned acrylic rubber and a vulcanizing agent, if necessary, together with other compounding agents, such as a commonly used roll, Banbury or internal mixer. Mixing using a mixer,
It can be manufactured by kneading. As other compounding agents, for example, reinforcing materials, fillers, antioxidants, antioxidants, light stabilizers, anti-scorch agents, crosslinking retarders, plasticizers, processing aids, lubricants, adhesives, lubricants, Flame retardants, fungicides, antistatic agents, coloring agents, and the like, but in the present invention, the type and amount of these compounding agents are not particularly limited, and may be selected according to the characteristics required for an oil-resistant hose. It can be determined appropriately.

In the present invention, if necessary, other rubber components or resin components can be mixed with the acrylic rubber of the present invention as long as the effects of the present invention are not impaired. As other rubber components, for example,
Acrylic rubber other than the acrylic rubber of the present invention, ethylene-
Acrylate copolymer rubber, olefin rubber such as EPDM, natural rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, chloroprene rubber, vinyl chloride elastomer, polyester elastomer, polyamide system Elastomers, polyurethane elastomers, polysiloxane elastomers and the like can be mentioned. Particularly preferred is the use of ethylene acrylate copolymer rubber,
By mixing the copolymer rubber with the above-mentioned acrylic rubber, a vulcanizate having an extremely small strength characteristic and a low elongation change after heat aging can be obtained.

The ethylene-acrylate copolymer rubber is obtained by copolymerizing ethylene and at least one of the above-mentioned alkyl acrylates, or at least one of the above-mentioned alkoxy acrylates, and a monomer for a crosslinking site. Rubber. The proportion of each of these monomers used in producing the copolymer rubber is not particularly limited, but ethylene is 20 to 75% by weight, preferably 30 to 65% by weight, more preferably 40 to 55% by weight, The monomer is 0 to 30% by weight, preferably 0.5 to 15% by weight,
More preferably, a copolymer rubber obtained by copolymerizing a monomer mixture containing 3 to 5% by weight, with the balance being an alkyl acrylate, is preferred. In this case, the alkyl acrylate is preferably methyl acrylate or ethyl acrylate. When the copolymer rubber is crosslinked with a crosslinking agent different from the acrylic rubber of the present invention, conventionally known various crosslinking site monomers can be used and are not particularly limited. When crosslinking with the same crosslinking agent as the acrylic rubber of the present invention, butenedioic acid monoesters such as monoalkyl maleate, monoalkoxyalkyl maleate, monoalkyl fumarate and monoalkoxyalkyl fumarate are preferred. The monoester in this case is the same as the monoester of fumaric acid monoester described above. The proportions of these cross-linking site monomers used are the same as the proportions used in the acrylic rubber of the present invention. The Mooney viscosity of the ethylene-acrylate copolymer rubber is the same as that of the acrylic rubber of the present invention.

When the acrylic rubber of the present invention and the ethylene-acrylate copolymer rubber are used as a mixture, the acrylic rubber is 50 to 90% by weight, preferably 70 to 85% by weight, and the copolymer rubber is 10 to 50% by weight. % By weight, preferably 15
３０30% by weight. Depending on the purpose of mixing the ethylene-acrylate copolymer rubber, it may not be necessary to cross-link the copolymer rubber, and in such a case, the copolymer rubber is not copolymerized with a monomer for a crosslinking site. The copolymer rubber can also be used. The ethylene-acrylate copolymer rubber is usually cross-linked, but a cross-linking agent different from the acrylic rubber of the present invention can be used, but it is preferable to co-cross-link with the same cross-linking agent as the acrylic rubber. In this case, the amounts of the crosslinking agent and the crosslinking accelerator are appropriately adjusted so as to satisfy the performance required for the oil-resistant rubber hose.

When the hose is manufactured using the rubber composition for manufacturing a hose of the present invention, the method of manufacturing the hose itself may be in accordance with a conventionally known method of manufacturing a hose, and is not particularly limited. or,
The structure of the hose is not particularly limited, and examples thereof include a fiber coating, a thread core, and a laminate with other rubber or resin.
Usually, a hose is manufactured by molding a rubber composition into a hose shape using an extruder, performing primary vulcanization in a steam can, and then performing secondary vulcanization in an oven under hot air. The oil-resistant hose of the present invention can be used for applications such as automobile fuel hoses, automobile ATF hoses, and air duct hoses.

[0025]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following, parts and percentages are by weight unless otherwise specified.

Examples 1 to 7 and Comparative Examples 1 to 16 Acrylic rubbers obtained by copolymerizing a fumaric acid monoester used in the present invention and acrylic rubbers of Comparative Examples were produced by ordinary emulsion polymerization. Table 1 shows the monomer composition of each acrylic rubber and the amount of carboxyl groups in the rubber.

Table 1

According to the compounding recipes shown in Tables 2 to 5, each acrylic rubber and each compounding agent excluding a vulcanizing agent and a vulcanization accelerator and optionally ethylene-acrylate copolymer rubber were mixed with a small Banbury (0.8 liter). By volume), and a vulcanizing agent and a vulcanization accelerator were mixed and kneaded with a 6-inch roll to the resulting mixture to prepare a vulcanizable rubber composition. Each vulcanizable rubber composition is press-vulcanized (primary vulcanization: 160 ° C. × 30
2) to obtain a vulcanized sheet having a thickness of 2 mm, which was secondarily vulcanized with heated air (170 ° C. × 4 hours). The vulcanization conditions when the primary vulcanization is performed in a steam can are the same as the above primary vulcanization conditions. Using this vulcanized sheet, the tensile strength elongation and 100% tensile stress under normal conditions are determined according to JIS K6251.
The hardness was measured according to JIS K6253. The heat aging property was measured according to JIS K6257, and indicated by a rate of change before heat load. Tables 2 to 5 show the results.
It was shown to.

Table 2 Note) Common to Tables 2 to 5 (D) Vamac G manufactured by Du Pont (ethylene about 46 to 48%, methyl acrylate about 50 to 50%)
48%, copolymer of about 3.5 to 4.5% of monomethyl maleate) (1) Seast 116 manufactured by Tokai Carbon Co., Ltd. (2) Grec G-8205 manufactured by Dainippon Ink and Chemicals, Inc. (3) 4,4'- Diamino diphenyl ether (4) Diak No. manufactured by Du Pont 3 (N, N'-dicinnamylidene-1,6-hexanediamine)

Table 3

Table 4

Table 5

As shown in Tables 2 to 5, when an acrylic rubber copolymerized with a fumaric acid monoester was used, regardless of the primary vulcanization method (press vulcanization, steam vulcanization),
Even after receiving a slow and severe heat load, the rate of change in strength (tensile strength) compared to the case of using an acrylic rubber copolymerized with a carboxyl group-containing monomer other than the fumaric acid monoester of the comparative example. Has been significantly improved. Using the rubber composition of each of the Examples and Comparative Examples, a primary vulcanization was performed by steam vulcanization, and a secondary vulcanization was performed in an oven to prepare a hose. Although it was excellent in characteristics, it was confirmed that all the hoses similarly manufactured using the rubber composition of the comparative example had a large decrease in strength after heat load, which hindered use. Further, in the present invention, by blending ethylene-acrylate copolymer rubber with fumaric acid monoester copolymerized acrylic rubber, excellent tensile strength, and excellent performance with a very small elongation change after heat aging. It can be seen that a vulcanizate having the same is obtained.

[0034]

According to the present invention, as in the case of press vulcanization or vulcanization under heated air, the decrease in strength after heat load is extremely small even when steam vulcanization is performed, and the pressure resistance is maintained. An oil-resistant hose having excellent resistance is provided. Such an oil resistant hose is suitable for a hose for transferring various control oils such as ATF oil transfer and power steering.

A preferred embodiment of the present invention is as follows. (1) In claim 1 or 2, the acrylic rubber is an alkyl acrylate or an alkyl acrylate and an alkoxyalkyl acrylate;
Acrylic rubber obtained by copolymerizing fumaric acid monoester in an amount of 0.1 to 40% by weight (based on a mixture of these monomers), preferably 0.2 to 20% by weight, and more preferably 0.5 to 10% by weight. It is. (2) The carboxyl content in the acrylic rubber described in (1) is 0.0005 to 0.06 mol in terms of a carboxyl functional group content (ephr) per 100 g of the acrylic rubber.
Preferably it is 0.003-0.020 mol, More preferably, it is 0.005-0.010 mol. (3) Mooney viscosity in the acrylic rubber according to (1) or (2) is 10 to 150, preferably 15 to 100,
More preferably, it is 20 to 60.

(4) The acrylic rubber according to any one of (1) to (3) has an alkyl acrylate content of 10 to 99.9% by weight, preferably 50 to 97.
8% by weight, more preferably 70 to 94.5% by weight, and the content of the alkoxyalkyl acrylate is 0 to
The rubber composition for an oil-resistant hose according to claim 1, which is 50% by weight, preferably 2 to 30% by weight, more preferably 5 to 20% by weight, and the oil-resistant hose according to claim 2. (5) In any one of (1) to (4), the fumaric acid monoester is an alkyl group having 1 to 10 carbon atoms of a fumaric acid monoalkyl ester or an alkylene group having 1 to 5 carbon atoms, Monoalkoxyalkyl fumarate having an alkoxy group having 1 to 5 carbon atoms, alkyl acrylate is an alkyl acrylate having 1 to 10 carbon atoms, and alkoxyalkyl acrylate is an alkylene group having an alkylene group. It has 1 to 5 carbon atoms and has an alkoxy group having 1 to 5 carbon atoms. (6) In any one of (1) to (5), the vulcanizing agent is a polyvalent primary amine or a compound containing a polyhydrazide group. (7) In claim 1 or 2, the acrylic rubber is used by being mixed with an ethylene acrylate copolymer rubber.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 35/02 C08L 35/02 F16L 11/04 F16L 11/04

Claims (2)

[Claims] 1. A rubber composition for an oil-resistant hose, comprising: an acrylic rubber obtained by copolymerizing an alkyl acrylate and a monoester of fumaric acid; and a vulcanizing agent. 2. An oil-resistant hose obtained by vulcanizing the rubber composition according to claim 1.