JPH06228402A - Acrylic rubber composition - Google Patents

Abstract

PURPOSE:To obtain an acrylic rubber excellent in tensile strength and oil resistance at high temperature. CONSTITUTION:The acrylic rubber composition consist essentially of a composition obtained by melting and blending (A) 60-99 pts. wt. acrylic rubber having a functional group capable of reacting with a carboxyl group or an amino group with (B) 1-40 pts.wt. polyamide resin (with the proviso that total amounts of the component A + the component B are 100 pts.wt.) at a temperature higher than the melting point of the polyamide resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an acrylic rubber composition which improves mechanical strength and maintains excellent strength at high temperatures without impairing various properties such as excellent heat resistance and oil resistance of acrylic rubber. Regarding

[0002]

2. Description of the Related Art In recent years, the properties required of rubber materials have become extremely severe. For example, in the field of automobiles, due to the higher performance of automobiles, stricter operating conditions due to compactness, and maintenance-free operation, the properties required for rubber materials used in these are much more stringent. Has become. Such a tendency is no exception in general industrial fields, and it is desired to further improve various properties such as heat resistance and oil resistance required for rubber materials.

Under such circumstances, acrylic rubber is a special synthetic rubber having excellent heat resistance, oil resistance, and ozone resistance, and is cheaper than fluororubber and silicone rubber, and therefore economical. In terms of heat resistance and oil resistance, there is an increasing demand to replace conventional nitrile-butadiene rubbers. Acrylic rubber crosslinked products are widely used in oil seals, O-rings, gaskets, backings, automobile hoses, etc., and the demand for them tends to increase. However, although acrylic rubber is excellent in heat resistance and oil resistance, it has low mechanical strength, especially low tensile strength. Therefore, it is necessary to use mechanical strength to improve heat resistance in acrylonitrile-butadiene rubber applications. Is a necessary condition.

For improving the mechanical strength, a method of reinforcing with short fibers has been used for a long time, but in order to improve the strength and stabilize the physical properties, it is important to adhere the interface between the short fibers and the matrix rubber. Therefore, a special adhesive or reaction agent is required, and it is desired to omit these for cost reduction and labor saving of the processing process. Attempts to blend rubber and polyamide resin into a composite have already been made. For example, JP-A-5
4-31456, JP-A-60-184556, and JP-A-6-184556.
2-57452, JP-A-63-191857, JP-A-6-
3-199755, JP-A-01-51449, JP-A-0
1-51459, JP-A-04-120167 and the like are aimed at a nylon-based thermoplastic elastomer, and are not intended to chemically crosslink rubber, but to obtain a soft polyamide resin.

JP-A-63-179945, JP-A-63-
179946 and JP-A-02-16138 propose a composite of non-oil resistant rubber such as natural rubber or ethylene-propylene-diene copolymer rubber and fibrous nylon. Adhesion between nylon and rubber is proposed. It is necessary to use a coupling agent or the like in order to improve, and the stability of quality becomes negative and the oil resistance is poor. In addition, it is intended to improve heat resistance, gasoline resistance, gasohol resistance, sour gasoline resistance, permeation resistance, and cold resistance by combining acrylonitrile-butadiene rubber, which is an oil resistant rubber, and polyamide resin. Kaihei 01-19334
No. 0, JP-A No. 01-198644, etc.), but it is limited to a polyamide resin having a low melting point and does not consider the chemical reaction between the resin and the matrix rubber.

[0006]

DISCLOSURE OF THE INVENTION The present invention improves the mechanical strength and the strength at high temperature without deteriorating various properties such as excellent heat resistance and oil resistance of acrylic rubber, and has a special reaction. It is intended to provide an acrylic rubber composition aiming to easily develop anisotropy such as short fiber reinforced rubber without using an agent.

[0007]

In order to solve the above problems, the present invention provides (A) 60 to 99 parts by weight of an acrylic rubber having a functional group capable of reacting with a carboxyl group or an amino group, and (B) a polyamide resin 1 -40 parts by weight (however,
(A) + (B) = 100 parts by weight) is provided to provide an acrylic rubber composition containing a composition obtained by melt-blending (A) + (B) = 100 parts by weight at a temperature equal to or higher than the melting point of a polyamide resin as a main component.

The acrylic rubber (A) used in the present invention has a functional group capable of addition reaction with an amino group such as a halogen element, an epoxy group or a carboxyl group as a reaction point, or a hydroxyl group, an amino group, an amide group or the like. It contains a functional group capable of addition reaction with a carboxyl group. Among these functional groups, a halogen element and an epoxy group are preferable, and an epoxy group is particularly preferable. Acrylic rubbers having functional groups can be obtained by copolymerization of monomers having these functional groups, addition and graft reaction of these functional groups to acrylic rubber, partial hydrolysis of acrylic rubber, and the like. it can. The content of the functional group can be appropriately adjusted according to the purpose.

As the acrylate-based monomer containing no functional group, which is the main component of the acrylic rubber, at least one selected from copolymerizable alkyl and alkoxyalkyl acrylates is used. Examples of alkyl acrylates include methyl acrylate, ethyl acrylate,
Alkyl acrylates in which the alkyl group has 1 to 8 carbon atoms, such as propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate are mentioned. Examples of alkoxyalkyl acrylates include alkoxy groups such as methoxymethyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, and alkoxy acrylates where the alkylene groups each have 1 to 4 carbon atoms.

The content of the acrylate-based monomer in the acrylic rubber is usually 50 to 99.8% by weight, preferably 8
It is in the range of 0 to 99.5% by weight. When it is less than 50% by weight, the balance of oil resistance, cold resistance and heat resistance is not good, and when it exceeds 99.8%, the effect of the functional group cannot be obtained. The acrylic rubber used in the present invention may be copolymerized with a copolymerizable monomer in an amount of less than 20% by weight, if desired, in order to impart a more preferable balance of physical properties. Examples of the copolymerizable monomer include α-methylstyrene, styrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride and ethylene.

To introduce a reactive group with a polyamide resin by copolymerization, halogen-containing monomers such as vinyl chloroacetate, vinyl bromoacetate, vinyl α-chloropropionate, allyl chloroacetate, allyl bromoacetate,
Examples thereof include chloroethyl acrylate, chloro-n-propyl acrylate, chloroethyl vinyl ether, and chloromethylstyrene. Examples of the epoxy group-containing monomer include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, and allyl glycidyl ether.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, monomethyl maleate, monoethyl maleate and monobutyl maleate. Is mentioned. Examples of the amino group-containing monomer include N, N-dimethylaminoethyl methacrylate, N, N-dimethyl acrylate, p-aminostyrene and the like.

Examples of the amide group-containing monomer include acrylamide, methacrylamide, N-methylol acrylamide and the like. Examples of the hydroxyl group-containing monomer include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate. The content of the reactive group-containing monomer in the acrylic rubber is usually 0.1 to 30% by weight, preferably 0.2 to 10%.
%, And more preferably 0.5 to 5 parts by weight.

As the crosslinking group of the acrylic rubber, the following unsaturated groups can be copolymerized in addition to the above reactive groups. For example, ethylidene norbornene, dicyclopentenyl acrylate, dicyclopentenyloxymethyl acrylate, dicyclopentenyloxyethyl acrylate, divinylbenzene, piperylene, isoprene, pentadiene, vinylcyclohexene, chloroprene, butadiene, dicyclopentadiene, ethylene glycol diacrylate, etc. Is mentioned.

The content of the monomer responsible for crosslinking in the acrylic rubber is preferably in the range of 0.1 to 10% by weight, more preferably 0.5 to 5% by weight. 0.1
If it is less than 10% by weight, the crosslinking will be insufficient, and if it exceeds 10% by weight, it will be over-crosslinked, resulting in poor normal state physical properties. The Mooney viscosity of the acrylic rubber used in the present invention (ML1 + 4, 100
C.) is usually 20 to 90.

As the polyamide resin (B), for example, a polyamide resin represented by the following general formula or a copolyamide resin can be used. (HN (CH ₂ ) mCO) k (1) (HN (CH ₂ ) mNHCO (CH ₂ ) nCO) k (2) (where n and m are integers of 1 to 12 and k is 100 to 6)
It is 10,000. )

Specific examples of the polyamide resin include nylon-46, nylon-6, nylon-66, nylon-
610, nylon-11, nylon-12, nylon-
6 and nylon-66 copolymer and the like. Among these, nylon-46, nylon-6, nylon-6
6, nylon-610, nylon-6 and nylon-66
The copolymers and the like have a melting point of higher than 200 ° C. and are preferable because an acrylic rubber composition having higher heat resistance can be obtained. When the melting point of the polyamide resin is 200 ° C. or lower, the compression set of the acrylic rubber composition tends to increase. From the viewpoint of workability of blending with acrylic rubber, a polyamide resin having a melting point of 300 ° C. or lower is preferably used.

Further, in order to prevent thermal deterioration of the acrylic rubber during melt blending, it is preferable to add an antioxidant. The antiaging agent is not particularly limited, and all usual antiaging agents can be used. Preferably, an amine anti-aging agent is effective, and examples thereof include 4,4 ′-(α, α-dimethylbenzyl) diphenylamine. The addition amount is 10% by weight or less, preferably 3% by weight or less, based on 100% by weight of the total of the blended products of (A) and (B).

As a method for blending the acrylic rubber and the polyamide resin, the temperature at the time of blending is set to a melting temperature of (B) or higher, and (A) and (B) are simultaneously charged and blended, and (A) is plasticized. A method in which (B) is added and blended, a method in which (B) is melted and then (A) is added and blended, and (A) and (B) are pre-blended at a low temperature and then kneaded at a high temperature. The method etc. are used.

Melt blending is carried out at a temperature above the melting point of the polyamide resin, preferably 15 to 15 above the melting point of the polyamide resin.
It is better to carry out at a temperature higher by 30 ° C. Therefore, as long as the processing machine can raise the temperature to 15 to 30 ° C. higher than the melting point of the polyamide resin to be used, an ordinary mixer such as a closed mixer or an extruder can be used. The mixing time varies depending on various conditions such as the number of rotations of the rotor and the filling rate of the blend with respect to the capacity, but it is necessary to have sufficient time to sufficiently carry out the addition reaction between (A) and (B). It is preferably 1 minute to 60 minutes. If the blending time is short, the reaction is difficult to be uniform, and if the blending time is long, the productivity is low and it is not preferable.

Before the polyamide resin is agglomerated, the blend is rapidly cooled from above the melting point of the polyamide resin to below the crystallization temperature, usually within 5 minutes, preferably within 1 minute, more preferably within 30 seconds. Is preferred. Immobilization of the polyamide resin by quenching can improve the tensile strength and stabilize the physical properties. Cooling includes water cooling, a mist cut method, cooling with a roll, and the like, but cooling with a roll is preferable.

The immobilized polyamide resin is finely dispersed in the acrylic rubber matrix. When such an acrylic rubber composition is sheet-rolled out or extruded by an extruder, the tensile strength in the sheet-out or extrusion direction is preferably 1.2 or more as compared with the tensile strength in the direction perpendicular to the direction. It is more than double, and sometimes 1.5 to 2.5 times improved. In the swelling with methyl ethyl ketone, the swelling in the grain direction is reduced by 10% or more, further by 15% or more, as compared with the swelling in the vertical direction, and the swelling property is improved.

As the cross-linking agent used for cross-linking the acrylic rubber, a suitable compound can be selected according to the kind of the cross-linking monomer introduced into the acrylic rubber. For example, in the case of halogen or epoxy group-containing acrylic rubber, hexamethylenediaminecarbamate / dibasic lead phosphite system, potassium stearate / promoter dipentamethylenethiuram tetrasulfide / promoter N, N′-diethylthiourea or ethylthiourea. System, soap (potassium stearate, sodium stearate, etc.) / Sulfur system, soap (potassium stearate, sodium stearate, etc.) / Accelerator dipentamethylene thiuram tetrasulfide system, diamine carbamate system (methylene biscyclohexyl amine carbamate etc.) , Organic carboxylic acid ammonium salt type (benzoate, adipine salt, etc.), dithiocarbamate type (accelerator zinc dimethyldithiocarbamate), polyamine type, polyamine /
Accelerator Guanidine compound system, polyepoxy compound / basic accelerator system, polyhalogen compound / soap / basic accelerator system, triazine compound / carbamate accelerator system and the like can be used.

When a diene compound or a dihydrodicyclopentadiene group-containing (meth) acrylic acid ester is copolymerized, a sulfur / vulcanization accelerator or organic peroxide used for crosslinking carbon-carbon double bonds and the like. A cross-linking agent used for general diene rubbers (styrene-butadiene rubbers, isoprene rubbers, etc.) can be preferably used.

The amount of the acrylic rubber crosslinking agent blended is (A)
And 0.05 to 10 parts by weight of component (B).
Parts by weight, preferably 1 to 7 parts by weight.

As the organic peroxide, di-t-butyl peroxide, di-t-amyl peroxide, t-butylcumyl peroxide, dicumyl peroxide,
1,4- (or 1,3-) di-t-butylperoxyisopropylbenzene, 2,2-di-t-butylperoxybutane, 2,2-di-t-butylperoxyoctane, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-
Butyl peroxy) hexyne-3, n-butyl-4,4
-Di-t-butylvalerate, 1,1-di-t-butylperoxycyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-di-t-butylperoxy-3 , 3,5-trimethylcyclohexane,
Dialkyl peroxides such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane;

T-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxypivalate, t-butylperoxymaleic acid, t-butylperoxyneodecanoate, t-butylperoxy Benzoate, di-t-butylperoxyphthalate, t-butylperoxydilaurate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane,
Peroxyesters such as t-butylperoxyisopropyl carbonate; ketone peroxides such as dicyclohexanone peroxide, and mixtures thereof. Above all, it is preferable to use an organic peroxide having a temperature giving a half-life of 1 minute in the range of 130 to 200 ° C., and particularly 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane, 2,5-dimethyl-
2,5-di (t-butylperoxy) hexyne-3, n
-Butyl-4,4-di-t-butyl valerate, t-butyl cumyl peroxide, dicumyl peroxide,
Organic peroxides such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane and 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferably used. it can.

Further, as a crosslinking aid for the organic peroxide,
For example, ethylene glycol diacrylate, trimethylolpropane triacrylate, triethylene glycol diacrylate, polyoxyethylene diacrylate,
Acrylic acid compounds such as pentaerythritol triacrylate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, methacrylic acid ester compounds such as triethylene glycol dimethacrylate, polyoxyethylene dimethacrylate, pentaerythritol trimethacrylate, ethylene bismaleimide, metaphenylene Maleimide compounds such as bismaleimide, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl itaconate, allyl compounds such as tetraallyloxyethane,
Other examples include divinylbenzene and divinyltoluene.

In the acrylic rubber composition of the present invention, other reinforcing agents and extenders such as carbon black, various silicates such as wet and dry silica, clay, talc and wollastonite, calcium carbonate, Surface treatment fillers such as carbonates such as magnesium carbonate, metal oxides such as zinc oxide, aluminum oxide and titanium oxide and their coupling agents, stabilizers, plasticizers, processing aids, dispersion aids, colorants Additives such as a pigment, an ultraviolet absorber, a flame retardant, a foaming agent, an anti-scorch agent, a tackifier, and a lubricant can be appropriately used if necessary. These additives can be mixed by a general kneader such as a roll or a Banbury mixer during or after melt blending.

The acrylic rubber composition is molded into a shape according to the purpose and undergoes a crosslinking step to obtain a final product. As the crosslinking temperature, a temperature of 120 ° C. or higher is usually suitable, and the crosslinking temperature is preferably 150 to 200 ° C. for 5 minutes to 1 hour. 1 to 10 at a temperature of 150 to 200 ° C, if necessary
Secondary vulcanization in time can be performed.

[0031]

EXAMPLES Next, examples of the present invention will be shown, but the present invention is not limited to these examples unless the gist thereof is exceeded. The percentages and parts shown in the examples are
All means% by weight and parts by weight. For the physical property evaluation test, the high temperature physical property test was conducted in accordance with JIS except that the measurement temperature was 150 ° C.
It carried out according to K6301.

In the swelling anisotropy test, the length of the vulcanized sheet is adjusted to the length of 38 by aligning the lengthwise direction of the punch with the grain direction and the vertical direction.
mm, width 2 mm, and thickness 2 mm test pieces were prepared, and the dimensional ratio before and after immersion in methyl ethyl ketone at 25 ° C. for 4 hours was determined, and this was taken as the swelling rate. That is, (swelling rate)
= (Length after swelling) ÷ (length before swelling). There were three test pieces, and the average value was taken. The swelling anisotropy was evaluated by the difference in swelling ratio between the grain direction and the vertical direction. If this difference is large, the anisotropy becomes remarkable. The grain direction in the physical property evaluation test is the sheet withdrawal direction when the acrylic rubber composition is withdrawn with a roll or the like, or the extrusion direction when the acrylic rubber composition is extruded with an extruder or the like. The direction perpendicular to the direction of pulling out or extruding the sheet or the thickness direction of the sheet was taken as the vertical direction. The formulations are shown in Tables 1 and 2, and the obtained results are shown in Tables 3 and 4, respectively.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

Example 1 As the acrylic rubber of (A), an epoxy group-containing acrylic rubber (acrylic rubber manufactured by Nippon Synthetic Rubber Co., Ltd .: AREX)
120) as the polyamide resin of (B), melting point 225
C. Nylon-6 (manufactured by Allied Chemical Co., Ltd., DL-
INT) pellets (particle size 1-2 mm) were used. Acrylic rubber 80 parts, polyamide resin 20 parts and amine anti-aging agent (Ouchi Shinko Chemical Co., Ltd., Nocrac CD)
Two parts by weight were heated and kneaded at 245 ° C. for 15 minutes with a 332 cc Haake kneader to melt-blend the acrylic rubber and the polyamide resin. To the resulting blend, 2 parts of stearic acid and carbon black (Tokai Carbon Co., Ltd.)
(Manufactured by MAF Carbon Black, Seast 116) 50 parts by mixing using a 200 cc Labo Plastomill, and finally by a roll, as a cross-linking agent, ammonium benzoate (manufactured by Ouchi Shinko Chemical Co., Ltd., Varnox AS-S) 1.5 parts was added. The composition to which the crosslinking agent was added was press-vulcanized at 170 ° C. for 20 minutes, and secondary vulcanization was performed at 175 ° C. for 4 hours in an oven to measure the vulcanized physical properties.

Examples 2, 3 Ratio of acrylic rubber (A) and polyamide resin (B),
(A) / (B) = 90/10, 70/30 except that
The same experiment as in Example 1 was performed. Example 4 A chlorine-containing acrylic rubber (manufactured by Japan Synthetic Rubber Co., Ltd., acrylic rubber: AREX 110) was used as the acrylic rubber, and the crosslinking agent (sodium stearate 2.
An experiment was performed in the same manner as in Example 1 except that 5 parts, 0.5 part of potassium stearate, and sulfur (0.3 parts by Tsurumi Chemical Industry Co., Ltd., Salfax PMC) were used.

Example 5 As a carboxyl group-containing acrylic rubber, a copolymer (prototype 1) of 98% by weight of ethyl acrylate, 1% by weight of acrylic acid and 1% by weight of vinyl acrylate was used.
Cross-linking aid (N, N'-m-phenylene dimaleimide, manufactured by Ouchi Shinko Kagaku, Barnock PM) 1.5 parts, organic peroxide (1,3-bis (tertiary butylperoxyisopropyl) benzene, chemical agent Akzo, Perkadox 14)
An experiment was conducted in the same manner as in Example 1 except that 1.5 parts was used.

Example 6 A copolymer (prototype 2) of 98% by weight of ethyl acrylate, 1% by weight of acrylamide and 1% by weight of dicyclopentadiphenylethyl acrylate was used as the amide group-containing acrylic rubber, and the same procedure as in Example 5 was performed. I experimented with.

Example 7 Nylon-12 having a melting point of 175 ° C. as a polyamide resin
(Toray Industries, Inc., Rilsan AMN) was used, and the experiment was performed in the same manner as in Example 1 except that the temperature of the melt blending was 210 ° C.

Example 8 As a polyamide resin, nylon-11 having a melting point of 186 ° C.
(Toray Industries, Ltd., Rilsan BMN) was used, and the same experiment as in Example 1 was performed except that the temperature of the melt blending was 220 ° C.

Example 9 Nylon-66 having a melting point of 255 ° C. was used as a polyamide resin.
(Ube Industries, Ltd., 2020B) was used, and the experiment was performed in the same manner as in Example 1 except that the temperature at the time of melt blending was 280 ° C.

Example 10 5 parts of 50 parts of carbon black were mixed and kneaded simultaneously with the melt blending of acrylic rubber and polyamide resin,
The remaining 45 parts were kneaded together with 2 parts of stearic acid, and finally 1.5 parts of a crosslinking agent (ammonium benzoate) was added by a roll. Others were the same as in Example 1.

Example 11 Using the same formulation as in Example 1, an acrylic rubber and a polyamide resin were mixed on a roll at room temperature before melt blending, and the mixture was set to L / D = 26, 270 ° C. in a twin-screw extruder. The same experiment as in Example 1 was carried out, except that melt blending was carried out with a residence time of 3 minutes.

Comparative Example 1 An acrylic rubber containing an epoxy group (AR
EX 120) was 100 parts and the polyamide resin was not used, and the same experiment as in Example 1 was carried out.

Comparative Example 2 Acrylic rubber containing chlorine (AREX)
110) 100 parts and no polyamide resin was used, and the same experiment as in Example 4 was carried out. Comparative Example 3 The blend ratio of acrylic rubber and polyamide resin was (A).
The same experiment as in Example 1 was carried out except that / (B) = 50/50.

Comparative Example 4 The same experiment as in Example 5 was carried out except that 80 parts of a homopolymer of ethyl acrylate (prototype 3) and 20 parts of nylon-6 were used as the acrylic rubber. Comparative Example 5 An experiment was conducted in the same manner as in Example 1 except that the polyamide resin was pulverized into fine powder (50 mesh) and the temperature at the time of melt blending was 200 ° C.

As can be seen from Tables 3 and 4, the examples have higher tensile strengths, especially tensile strength in the grain direction and 1
It can be seen that the tensile strength at 50 ° C. is greatly improved.

[0050]

The acrylic rubber composition of the present invention obtained by melt-blending a polyamide resin with an acrylic rubber having a functional group capable of reacting with a carboxyl group or an amino group of the polyamide resin has excellent heat resistance of the acrylic rubber. ,
It was clarified that it has more excellent mechanical strength and high temperature physical properties than acrylic rubber without impairing various properties such as oil resistance. Utilizing these properties, various sealing materials (gaskets, O-rings, packings, oil seals, etc.), various hoses (fuel hoses, hydraulic oil hoses,
Widely used for various rubber parts and products that use oil-resistant rubber such as inner tubes and outer skins of lubricating oil hoses, car cooler hoses, high-pressure hoses, diaphragms, various belts (transmission belts, conveyor belts, etc.) and rolls. It can be used effectively.

Continuation of the front page (72) Inventor Ken Akiyama 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. (A) 60 to 99 parts by weight of an acrylic rubber having a functional group capable of reacting with a carboxyl group or an amino group, and (B) 1 to 40 parts by weight of a polyamide resin (however,
An acrylic rubber composition comprising as a main component a composition obtained by melt-blending (A) + (B) = 100 parts by weight) at a temperature equal to or higher than the melting point of a polyamide resin.