JP6965898B2 - Composition for rubber - Google Patents

Description

The present invention relates to a composition for rubber containing an epichlorohydrin-based polymer as an essential component and a rubber material obtained from the composition. The rubber material is preferably a heat-resistant rubber material obtained from a heat-resistant rubber composition, and the crosslinked heat-resistant rubber material may be referred to as a “crosslinked rubber material”.

In the fields of buildings, aircraft, automobiles, railroad vehicles, computers, automobile tires, etc., materials mainly using natural rubber are used as materials for the purpose of seismic isolation, vibration control, vibration control, and vibration control. There is. However, the natural rubber material has a problem of insufficient heat resistance and ozone resistance. Therefore, in order to improve the heat resistance, a technique using EPDM having excellent heat resistance without a double bond in the main chain has been disclosed (Patent Documents 1 and 2), and these are particularly engine mounts, body mounts, and cabs. It was developed as an anti-vibration rubber for automobiles that is placed and used in high temperature environments such as mounts, member mounts, strut mounts, center bearing supports, torsional dampers, muffler hangers, and suspension bushes.

Japanese Unexamined Patent Publication No. 2005-113093 JP-A-2009-298949

The EPDM rubber is not always excellent in oil resistance, and further improvement is required. By the way, as a rubber having excellent oil resistance, an epichlorohydrin rubber material using an epichlorohydrin polymer is known. Epichlorohydrin rubber materials are widely used as fuel hoses, air hoses, tube materials, and sealing materials even in automobile applications by taking advantage of their heat resistance, oil resistance, ozone resistance, and the like.

However, epichlorohydrin rubber materials do not have sufficient low dynamic magnification, and in the fields of buildings, aircraft, automobiles, railroad vehicles, computers, automobile tires, etc., sound absorption, seismic isolation, vibration control, vibration control, and vibration control It was not used as a material for vibration.
That is, there are currently few options for materials that are excellent in heat resistance, oil resistance, and ozone resistance, and are also excellent in sound absorption, seismic isolation, vibration control, vibration control, or vibration control.

Therefore, it is an object of the present invention to provide a rubber material using an epichlorohydrin-based polymer and a composition for the above rubber material.

The present inventors have found an epichlorohydrin-based rubber material obtained from a composition containing carbon black, an epichlorohydrin-based polymer having a constituent unit derived from ethylene oxide in a specific range.

That is, the rubber composition and rubber material of the present invention that have solved the above problems are as follows.
Item 1 (A) An epichlorohydrin-based polymer having a structural unit derived from ethylene oxide and (B) an epichlorohydrin-based polymer containing carbon black and having a structural unit derived from (A) ethylene oxide. , A composition for rubber having 3 to 30 mol% of a structural unit derived from ethylene oxide.
Item 2 (A) For rubber according to Item 1, wherein the content of (B) carbon black is 5 to 25 parts by weight with respect to 100 parts by weight of the epichlorohydrin-based polymer having a structural unit derived from ethylene oxide. Composition.
Item 3 The rubber composition according to Item 1 or 2, further comprising (C) a cross-linking agent.
Item 4 A rubber material produced from the composition for rubber according to any one of Items 1 to 3.
Item 5 An automobile hose material, a tube material, a mounting material, and a sealing material made from the rubber material according to Item 4.

The rubber material obtained by the present invention has good heat resistance and has an excellent balance between low dynamic ratio and damping property, so that it is used as a mounting material (particularly used for an engine mount) in which both characteristics are required at the same time. Material) is suitable.

Hereinafter, the rubber composition and the rubber material of the present invention will be described in detail, with the heat-resistant rubber composition obtained by cross-linking the heat-resistant rubber composition and the heat-resistant rubber composition as a representative. The heat-resistant rubber composition contains (A) an epichlorohydrin-based polymer having a structural unit derived from ethylene oxide and (B) carbon black, and epichloro having a structural unit derived from (A) ethylene oxide. The hydrin-based polymer has 3 to 30 mol% of structural units derived from ethylene oxide.

The (A) epichlorohydrin-based polymer having a structural unit derived from ethylene oxide used in the composition for heat-resistant rubber is a polymer having a structural unit derived from epichlorohydrin and a structural unit derived from ethylene oxide. Containing structural units derived from alkylene oxides other than ethylene oxide such as propylene oxide and n-butylene oxide, and glycidyls such as methylglycidyl ether, ethylglycidyl ether, n-glycidyl ether, allylglycidyl ether and phenylglycidyl ether. May be good.

The epichlorohydrin-based polymer having a structural unit derived from (A) ethylene oxide preferably contains 40 mol% or more of the structural unit derived from epichlorohydrin, and more preferably 50 mol% or more. It is particularly preferably contained in an amount of 70 mol% or more, more preferably contained in an amount of 97 mol% or less, and particularly preferably contained in an amount of 95 mol% or less.

(A) The epichlorohydrin-based polymer having a structural unit derived from ethylene oxide contains 3 mol% or more of the structural unit derived from ethylene oxide. Further, the constituent unit derived from the ethylene oxide preferably contains 5 mol% or more, and more preferably 7 mol% or more. Further, the constituent unit derived from ethylene oxide is contained in an amount of 30 mol% or less, preferably 20 mol% or less, and more preferably 15 mol% or less. Within these ranges, it is preferable in that both low dynamic magnification and excellent damping properties are satisfied.

In the present invention, the molar ratio derived from each structural unit in the epichlorohydrin-based polymer having the structural unit derived from (A) ethylene oxide is applied as it is if it is composed of a single polymer. If it is composed of a plurality of polymers, it can be calculated from the molar ratio of each polymer and the ratio of the weight occupied by each polymer in (A) epichlorohydrin-based polymer.

(A) When the epichlorohydrin-based polymer having a structural unit derived from ethylene oxide is composed of a plurality of polymers, the epichlorohydrin homopolymer, the epichlorohydrin-ethylene oxide copolymer, and the epichlorohydrin-ethylene oxide copolymer are used. Chlorohydrin-propylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer, epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymer, etc. The coalescence or copolymer can be used alone or in combination of two or more. Examples of these homopolymers or copolymers include Epichromer H, Epichromer C, Epichromer CG, Epichromer D, Epichromer DG, and Epion manufactured by Osaka Soda Co., Ltd.

The copolymer composition of the epichlorohydrin homopolymer, the epichlorohydrin-ethylene oxide copolymer, and the epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer is determined by the chlorine content and the iodine value.
The chlorine content is measured by potentiometric titration according to the method described in JIS K7229. From the obtained chlorine content, the mole fraction of the constituent unit derived from epichlorohydrin is calculated.
The iodine value is measured by a method according to JIS K6235. From the obtained iodine value, the mole fraction of the constituent unit derived from allyl glycidyl ether is calculated.
The mole fraction of the constituent unit derived from ethylene oxide is calculated from the mole fraction of the constituent unit derived from epichlorohydrin and the molar fraction of the constituent unit derived from allylglycidyl ether.

(A) The molecular weight of the epichlorohydrin-based polymer having a structural unit derived from ethylene oxide is not particularly limited, but if the molecular weight is usually _{about ML 1 + 4} (100 ° C.) = 30 to 150 on the Mooney viscosity display. good.

The epichlorohydrin-based polymer can be produced by a solution polymerization method, a slurry polymerization method, or the like in a temperature range of 20 to 100 ° C. using a catalyst capable of ring-opening polymerization of an oxylan compound. Examples of such a catalyst include a catalyst system in which organic aluminum is mainly used and reacted with an oxo acid compound such as water or phosphorus or acetylacetone, a catalyst system in which organic zinc is mainly used and water is reacted with the catalyst system, and organic tin. -A phosphate ester condensate catalyst system and the like can be mentioned. For example, the polyether copolymer of the present invention can be produced using the organic tin-phosphate ester condensate catalyst system described in US Pat. No. 3,773,694. When copolymerizing by such a production method, it is preferable to copolymerize these components substantially randomly.

Examples of the (B) carbon black used in the heat-resistant rubber composition of the present invention include furnace black, acetylene black, thermal black, channel black, graphite, and the like, and specific examples thereof include SAF, ISAF, HAF, and EPC. , XCF, FEF, GPF, HMF, SRF, FT, MT can be exemplified. These carbon blacks may be used alone or in combination of two or more.

The (B) carbon black, the nitrogen adsorption specific surface area (N2SA) is preferably at least 5 m ² / g, more preferably not less than 7m ² / g, more 10 m ² / g is particularly preferred. ^{The upper limit is preferably 180 m 2} / g or less from the viewpoint of generally being easily available.

As the carbon black, the dibutyl phthalate (DBP) oil absorption is preferably 15 ml / 100 g or more, more preferably 20 ml / 100 g or more, and particularly preferably 30 ml / 100 g or more. The upper limit is preferably 175 ml / 100 g or less, more preferably 170 ml / 100 g or less, from the viewpoint of generally being easily available.

In the heat-resistant rubber composition, the content of (B) carbon black is preferably 5 parts by weight or more, preferably 7 parts by weight or more, based on 100 parts by weight of the (A) epichlorohydrin-based polymer. It is more preferably 25 parts by weight or less, and more preferably 15 parts by weight or less. Satisfying these ranges enables both low dynamic magnification and excellent damping at an even better level.

The heat-resistant rubber composition may further contain (C) a cross-linking agent. The cross-linking agent (C) is not particularly limited as long as it can cross-link the epichlorohydrin-based polymer. Known cross-linking agents that utilize the reactivity of chlorine atoms, that is, polyamine-based cross-linking agents, thiourea-based cross-linking agents, thiadiazol-based cross-linking agents, triazine-based cross-linking agents, quinoxaline-based cross-linking agents, bisphenol-based cross-linking agents, and the like. Known cross-linking agents that utilize the reactivity of the side chain double bond, for example, organic peroxide-based cross-linking agents, sulfur, morpholine polysulfide-based cross-linking agents, thiuram polysulfide-based cross-linking agents, and the like can be exemplified.

Examples of polyamine-based cross-linking agents include ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, p-phenylenediamine, cumenediamine, N, N'-dicinnamylidene-1,6-hexanediamine, ethylenediamine carbamate, and hexamethylene. Examples include diamine carbamate.
Examples of the thiourea-based cross-linking agent include 2-mercaptoimidazoline (ethylene thiourea), 1,3-diethyl thiourea, 1,3-dibutyl thiourea, and trimethyl thiourea.
Examples of the thiadiazole-based cross-linking agent include 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-1,3,4-thiadiazole-5-thiobenzoate and the like.
Examples of the triazine-based cross-linking agent include 2,4,6-trimercapto-1,3,5-triazine, 2-hexylamino-4,6-dimercaptotriazine, 2-diethylamino-4,6-dimercaptotriazine, 2 -Cyclohexylamino-4,6-dimercaptotriazine, 2-dibutylamino-4,6-dimercaptotriazine, 2-anilino-4,6-dimercaptotriazine, 2-phenylamino-4,6-dimercaptotriazine, etc. Can be mentioned.
Examples of the quinoxaline-based cross-linking agent include 2,3-dimercaptoquinoxaline, quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline-2,3-dithiocarbonate, 5,8-dimethylquinoxaline-2,3-dithiocarbonate and the like. Can be mentioned.
Examples of the bisphenol-based cross-linking agent include bisphenol AF and bisphenol S.
Examples of the organic peroxide-based cross-linking agent include tert-butyl hydroperoxide, p-menthan hydroperoxide, dicumyl peroxide, tert-butyl peroxide, and 1,3-bis (tert-butyl peroxyisopropyl) benzene. Examples thereof include 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, benzoyl peroxide, and tert-butylperoxybenzoate.
Examples of the morpholine polysulfide-based cross-linking agent include morpholine disulfide.
Examples of the thiuram polysulfide-based cross-linking agent include tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, dipentamethylene thiuram tetrasulfide, and dipentamethylene thiuram hexasulfide.

Among these, thiourea-based cross-linking agents, quinoxaline-based cross-linking agents, and triazine-based cross-linking agents are preferable, and 2-mercaptoimidazoline (also referred to as ethylene thiourea), 6-methylquinoxaline-2,3-dithiocarbonate, 2,4. 6-Trimercapto-1,3,5-triazine (also referred to as 2,4,6-trimercapto-S-triazine) is particularly preferred. (C) The cross-linking agent may be used alone or in combination of two or more.

In the heat-resistant rubber composition, the content of the (C) cross-linking agent is 0.1 part by weight or more with respect to 100 parts by weight of the epichlorohydrin-based polymer having a structural unit derived from (A) ethylene oxide. It is preferably 10 parts by weight or less. The lower limit is particularly preferably 0.3 parts by weight or more, and the upper limit is particularly preferably 5 parts by weight or less.

Addition of compounding agents other than the above, for example, acid receiving agents, lubricants, antioxidants, antioxidants, ultraviolet absorbers, light stabilizers, etc., to the heat-resistant rubber composition as long as the effects of the present invention are not impaired. Agents, reinforcing agents, plasticizers, processing aids, flame retardants, cross-linking accelerators, cross-linking retarders, kneading accelerators and the like can be further optionally blended. Further, it is also possible to blend rubber, resin and the like, which are usually performed in the art, as long as the characteristics of the present invention are not lost.

In the composition for heat-resistant rubber, a known (D) acid receiving agent can be used depending on the cross-linking agent, and a metal compound and / or an inorganic microporous crystal is used.

Examples of the metal compound include oxides of Group II (Groups 2 and 12) metals in the periodic table, hydroxides, carbonates, carboxylates, silicates, borates, phosphites, and Periodic Table IV. Metal compounds such as oxides of non-lead metals of groups (Groups 4 and 14), basic carbonates, basic carboxylates, basic subphosphates, basic sulfites, tribasic sulfates, etc. Can be mentioned.

Specific examples of the metal compound include magnesium oxide, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, sodium carbonate, quicklime, calcium phosphate, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, and calcium phthalate. , Calcium silicate, Zinchua, tin oxide, tin stearate, basic tin phosphite, and the like. Particularly preferable acid receiving agents include magnesium oxide, calcium carbonate, slaked lime, and quicklime.

The inorganic microporous crystal means a crystalline porous body, and is clearly distinguishable from an amorphous porous body such as silica gel or alumina. Examples of such inorganic microporous crystals include zeolites, alumina phosphate type molecular sieves, layered silicates, hydrotalcites, alkali metal titanates and the like. Particularly preferable acid receiving agents include hydrotalcites.

Zeolites are not only natural zeolites, but also various zeolites such as A-type, X-type, and Y-type synthetic zeolites, sodalites, natural or synthetic mordenites, and ZSM-5, and metal substituents thereof. It may be used or may be used in combination of two or more kinds. The metal of the metal substituent is often sodium. As the zeolites, those having a large acid receptivity are preferable, and type A zeolites are preferable.

The hydrotalcites have the following general formula (1).
Mg _X Zn _Y Al _Z (OH) _{(2 (X + Y) + 3Z-2)} CO ₃・ wH ₂ O (1)
In the formula, X and Y are represented by 0 to 10 real numbers having a relationship of X + Y = 1 to 10, Z is a 1 to 5 real number, and W is a 0 to 10 real number.
Specific examples of hydrotalcites include Mg _4.5 Al ₂ (OH) ₁₃ CO ₃・ 3.5H ₂ O, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ , Mg ₄ Al ₂ (OH) ₁₂ CO ₃・ 3. _{5H 2 O, Mg 5 Al 2} (OH) 14 CO 3 · 4H 2 O, Mg 3 Al 2 (OH) 10 CO 3 · 1.7H 2 O, Mg 3 ZnAl 2 (OH) 12 CO 3 · 3.5H ₂ O, Mg ₃ ZnAl ₂ (OH) ₁₂ CO ₃ , Mg _4.3 Al ₂ (OH) _12.6 CO ₃・ 3.5H ₂ O and the like can be mentioned.

In the heat-resistant rubber composition, the content of the (D) acid-receiving agent is preferably 0.2 parts by weight or more with respect to 100 parts by weight of the (A) epichlorohydrin-based polymer, and is preferably 1 part by weight. It is particularly preferably parts or more, more preferably 50 parts by weight or less, and particularly preferably 20 parts by weight or less. (D) If the content of the acid receiving agent is less than 0.2 parts by weight, the cross-linking becomes insufficient, and if it exceeds 50 parts by weight, the cross-linked product becomes too rigid, and the epichlorohydrin-based rubber composition is cross-linked. There is a risk that the physical properties normally expected as the obtained crosslinked product cannot be obtained.

Specific examples of the lubricant include paraffin waxes such as paraffin waxes and hydrocarbon waxes and hydrocarbon resins; fatty acids such as stearic acid and palmitic acid; fatty acid amides such as stearic acid and oleyl amide; n-butyl. -Fatty acid esters such as stearate; sorbitan fatty acid esters; fatty alcohols; etc. may be mentioned, and these may be used alone or in combination of two or more.

Known anti-aging agents include amine-based anti-aging agents, phenol-based anti-aging agents, benzimidazole-based anti-aging agents, dithiocarbamate-based anti-aging agents, thiourea-based anti-aging agents, and organic thioic acid-based anti-aging agents. , Hypophosphate-based anti-aging agents are exemplified, and these may be used alone or in combination of two or more. Preferably, it is an amine-based anti-aging agent, a phenol-based anti-aging agent, a benzimidazole-based anti-aging agent, a dithiocarbamate-based anti-aging agent, and more preferably a dithiocarbamate-based anti-aging agent.

As the plasticizer, a phthalic acid derivative such as dioctyl phthalate, an adipic acid derivative such as dibutyldiglycol-adipate or di (butoxyethoxy) ethyl adipate, a sebacic acid derivative such as dioctyl sebacate, and a trimellitic acid such as trioctyl remeritate. Merit acid derivatives and the like can be mentioned, and these may be used alone or in combination of two or more.

As the kneading accelerator, an aromatic mercaptan compound, an aromatic disulfide compound, an aromatic mercaptan metal compound, or a mixed compound thereof can be used, and typically o, o-dibenzamide diphenyl disulfide can be used. Can be mentioned.

In order to produce the heat-resistant rubber composition, any mixing means conventionally used in the field of polymer processing, for example, a mixing roll, a Banbury mixer, various kneaders and the like can be used.

The heat-resistant rubber material is produced from the heat-resistant rubber composition. Since it is generally obtained by cross-linking, it can also be described as a cross-linked product or a cross-linked rubber material.

The heat-resistant rubber material is usually obtained by heating to 100 to 200 ° C. The cross-linking time varies depending on the temperature, but is usually between 0.5 and 300 minutes. As the method of cross-linking molding, any method such as compression molding by a mold, injection molding, steam can, air bath, heating by infrared rays or microwaves can be used.

The tensile strength (TB) of the rubber material of the present invention is, for example, 1 MPa or more, preferably 3 MPa or more, and more preferably 5 MPa or more. The upper limit is not particularly limited, but for example, there is no problem in practical use even if it is about 20 MPa or less or about 15 MPa or less.

The elongation (EB) of the rubber material of the present invention is, for example, 100% or more, preferably 200% or more, and more preferably 300% or more. The upper limit of the elongation (EB) is not particularly limited, but for example, even if it is about 800% or less or 600% or less, there is no practical problem.

The heat resistance of the rubber material of the present invention can be evaluated based on the rate of change of each physical property before and after the heat resistance test at 125 ° C. for 168 hours (see the following formula).
Rate of change (%) = {(Physical characteristics after heat resistance test-Physical properties before heat resistance test) / Physical properties before heat resistance test} x 100
In addition, the physical characteristics before the heat resistance test may be referred to as normal physical properties in the present specification.
The rate of change in the tensile strength (TB) of the rubber material of the present invention may be, for example, -30% or more, preferably -25% or more, more preferably -20% or more, for example, 30% or less. , 20% or less, and may be 10% or less.
The rate of change in elongation (EB) of the rubber material of the present invention may be, for example, -40% or more, preferably -30% or more, more preferably -20% or more, and may be, for example, 10% or less.

The rubber material of the present invention can be suitably used for anti-vibration and seismic isolation rubber for rubber for railway vehicles, rubber for industrial machinery, seismic isolation rubber for construction, seismic isolation rubber support, rubber for automobiles such as mounts, etc. In particular, it is suitably used for a mount material (particularly a material used for an engine mount) having an excellent balance between heat resistance, low dynamic ratio and damping property.

This application claims the benefit of priority under Japanese Patent Application No. 2017-022559 filed on February 9, 2017. The entire contents of the specification of Japanese Patent Application No. 2017-022559 filed on February 9, 2017 are incorporated herein by reference.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to this description.

Examples 1 to 3 and Comparative Examples 1 to 5
Each material was kneaded with a kneader and an open roll according to the formulation shown in Table 1 to prepare an uncrosslinked rubber sheet having a thickness of 2 to 2.5 mm. Further, the uncrosslinked rubber sheet was press-crosslinked at 170 ° C. for 15 minutes to obtain a primary crosslinked product having a thickness of 2 mm. Further, this was heated in an air oven at 150 ° C. for 2 hours to obtain a secondary crosslinked product.
In order to determine the dynamic characteristics of the secondary crosslinked product (rubber material), the displacement amount of the rubber material test piece with respect to the load was measured using a dynamic servo manufactured by Saginomiya Seisakusho Co., Ltd. The static spring constant (Ks) is calculated based on the ratio of the static load to the displacement in the 1 to 2 mm section when the test piece is compressed to 0 to 3 mm, and the dynamic spring constant (Kd) is the preset compression of the test piece. It was calculated based on the ratio of dynamic load and displacement when the rate was 5%, the strain amplitude was ± 0.1%, and the frequency was 100 Hz.
In order to determine the tan δ of the secondary crosslinked product (rubber material), the displacement amount of the rubber material test piece with respect to the load was measured using a dynamic servo manufactured by Saginomiya Seisakusho Co., Ltd. Tan δ was determined from the load-displacement amount relationship when the preset compressibility of the test piece during dynamic measurement was 5%, the strain amplitude was 0.25 mm, and the frequency was 15 Hz.
The tensile properties (tensile strength (TB), elongation (EB)) of the secondary crosslinked product under normal conditions were determined by performing a tensile test according to JIS K6251.
Further, the secondary crosslinked product (rubber material) was subjected to a heat resistance test at 125 ° C. for 168 hours according to the JIS K6257 accelerated aging test A-2 method, and the tensile properties (tensile strength (TB)) of the rubber material after the heat resistance test. , Elongation (EB)) was determined by performing a tensile test according to JIS K6251. Then, the rate of change (ΔTB, ΔEB) of each physical property (TB, EB) before and after the heat resistance test was calculated based on the following formula, and the heat resistance was evaluated.
Rate of change (%) = {(Physical characteristics after heat resistance test-Normal physical properties) / Normal physical properties} x 100
Table 2 shows the results of each evaluation of the rubber material.

From the examples in Tables 1 and 2, it is shown that the heat-resistant rubber material obtained from the rubber composition of the present invention has excellent heat resistance and an excellent balance between low dynamic ratio and damping property. Was done.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a crosslinked rubber material based on an epichlorohydrin-based polymer and having an excellent low dynamic ratio. Therefore, from the heat-resistant rubber composition and heat-resistant rubber material of the present invention, vibration isolation of rubber for railway vehicles, rubber for industrial machinery, seismic isolation rubber for construction, seismic isolation rubber support, rubber for automobiles such as mounts, etc. It can be suitably used for seismic isolation rubber, and is particularly preferably used for a mounting material having an excellent balance between heat resistance, low dynamic ratio and damping property.

Claims (5)

The epichlorohydrin-based polymer having a structural unit derived from (A) ethylene oxide and the epichlorohydrin-based polymer containing (B) carbon black and having a structural unit derived from (A) ethylene oxide are ethylene oxide. A composition for rubber used as a mounting material, which has 3 to 30 mol% of a structural unit derived from. The composition for rubber according to claim 1, wherein the content of (B) carbon black is 5 to 25 parts by weight with respect to 100 parts by weight of the epichlorohydrin-based polymer having a structural unit derived from (A) ethylene oxide. thing. The rubber composition according to claim 1 or 2, further comprising (C) a cross-linking agent. A rubber material produced from the rubber composition according to any one of claims 1 to 3. Automotive mount materials made of a rubber material according to claim 4.