JP2005248022A - Crosslinkable rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crosslinkable rubber composition having good workability and storage stability and excellent in adhesion to a metal and glass. <P>SOLUTION: The crosslinkable rubber composition comprises (A) 100 pts. mass epoxidized diene rubber having 0.15-7 meq/g of epoxy groups in the molecule and a number average molecular weight of 10,000-100,000, (B) 0.1-300 pts. mass solid rubber, (C) 0.1-1,500 pts. mass filler, and (D) 0.1-50 pts. mass crosslinking agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a crosslinkable rubber composition that can be suitably used for automobile bodies, sealing materials for building materials, and the like.

Conventionally, as a sealing material for automobile bodies, for example, a composition mainly composed of rubber, a softening agent and an inorganic filler is formed into a tape shape by extrusion molding. The rubber was vulcanized and foamed by heating in the baking process after electrodeposition coating and pasting to the vehicle body (see Patent Document 1). However, the sticking work by a person may vary, resulting in poor filling.
In order to solve such problems and improve the filling accuracy and workability, it has been proposed to paste the sealing material composition into a paste and mechanically apply it. For example, paste-type heat foam filling that blends liquid rubber, unvulcanized rubber, vulcanizing agent, vulcanization accelerator, softener, foaming agent, foaming aid, scaly inorganic filler and thixotropic agent in specific quantity ratio Material (refer to Patent Document 2); inorganic filler, tackifier, sulfur-based crosslinking agent for a mixture of a crosslinkable rubber having a number average molecular weight of 500 to 20000 and a crosslinkable solid rubber having a number average molecular weight of 50000 or more And a rubber composition in which a foaming agent is blended in a specific amount ratio as required (see Patent Document 3); an inorganic filler and a tackifier for a mixture of a rubber having a number average molecular weight of 500 to 20000 and a thermoplastic elastomer A steel sheet reinforcing sheet provided with a foamed resin layer and a constraining layer containing a crosslinking agent, a foaming agent and, if necessary, a softening agent (see Patent Document 4); a rubber component having a vulcanizable double bond, and center Heat vulcanizable rubber composition comprising a room-temperature solid vulcanizing agent and / or a room-temperature solid vulcanization accelerator having a surface coated with a fine powder (eg, titanium oxide) having a diameter of 2 μm or less at a specific ratio (Patent Document 5) Reference); Reinforcing sheet for automobile body steel sheet, in which a constrained layer is laminated on an unvulcanized sheet obtained by blending a modified liquid rubber with an inorganic filler, a tackifier, and a sulfur-based cross-linking agent in a specific ratio. (See Patent Document 6).

JP-A-1-167392 JP-A-5-59345 JP-A-5-339429 JP 7-68695 A JP-A-9-95561 JP 2001-38842 A

The “liquid rubber” that is a component of the composition of Patent Document 2 is disclosed as being substantially useful as liquid synthetic natural rubber (LIR), liquid butadiene rubber (LBR), and the like. In the case of a composition containing a liquid rubber not having a group, the adhesion to an adherend such as a metal is not always sufficient, and there is room for improvement.
It is polybutadiene that is substantially useful as “a crosslinkable rubber” having a number average molecular weight of 500 to 20000, which is a component of the composition of Patent Document 3 and a component of the foamed resin layer of Patent Document 4. Rubber (BR), styrene-butadiene rubber (SBR) and the like, and particularly preferred molecular weight is disclosed to be 1000 to 10,000. In addition, Patent Document 3 describes that these rubbers preferably have a functional group such as a hydroxyl group, a carboxyl group, an amino group, an isocyanato group, an epoxy group, and a vinyl group. However, since sulfur vulcanization does not proceed sufficiently, there is a problem that uncrosslinked components remain and the physical properties of the resulting composition are lowered.

What is disclosed as substantially useful as a “rubber having a vulcanizable double bond”, which is a constituent of the composition of Patent Document 5, is solid at room temperature or liquid and does not have a functional group 1,4-polybutadiene rubber, polybutadiene isoprene rubber, and the like, and no description is given about the degree of improvement in adhesion to an adherend such as metal.
Furthermore, as the “modified liquid rubber” which is a constituent component of the unvulcanized sheet of Patent Document 6, it is possible to use a maleic compound modified, an epoxidized modified, a phenolized modified, an acrylate modified, an amine using a double bond of the main chain. Although it has been described that it has been subjected to modification treatment such as modification with imide, imidization, modification with esterification, modification with carboxylation, etc., what is substantially useful is the reaction of maleic anhydride with liquid polybutadiene This is a modified maleic acid-modified polybutadiene rubber, and the liquid rubber subjected to carboxy modification such as maleic acid group is a metal contained in zinc di-n-butyldithiocarbide (ZnBDC) used as a vulcanization accelerator. In other words, the storage stability of the unvulcanized sheet is poor.
Therefore, an object of the present invention is to provide a crosslinkable rubber composition having good workability and storage stability and excellent adhesion to metals and glass.

According to the present invention, the above object is
(1) (A) With respect to 100 parts by mass of epoxidized diene rubber containing an epoxy group in the range of 0.15 to 7 meq / g and a number average molecular weight of 10,000 to 100,000, (B ) Containing 0.1 to 300 parts by weight of solid rubber, (C) 0.1 to 1500 parts by weight of filler, and (D) 0.1 to 50 parts by weight of crosslinking agent. A crosslinkable rubber composition comprising:
(2) From the structural unit selected from epoxidized diene rubber (A) isoprene; butadiene; a mixture of isoprene and butadiene; a mixture of isoprene and styrene; a mixture of butadiene and styrene; a mixture of butadiene, isoprene and styrene; (1) a crosslinkable rubber composition obtained by epoxidizing a carbon-carbon double bond possessed by a (co) polymer; and (3) the crosslinkability of (1) or (2) A sealing material, characterized by using a rubber composition;
Is achieved by providing

  According to the present invention, a crosslinkable rubber composition having good workability and storage stability and excellent adhesion to metals and glass can be obtained.

  The epoxidized diene rubber (A) that is a constituent of the crosslinkable rubber composition of the present invention is preferably composed of a butadiene unit and / or an isoprene unit and, if necessary, a styrene unit, for example, polybutadiene, polyisoprene. Diene rubbers such as styrene-butadiene random copolymer, styrene-isoprene random copolymer, butadiene-isoprene random copolymer, styrene-butadiene-isoprene random copolymer, polybutadiene-polyisoprene block copolymer It is obtained by epoxidizing the carbon-carbon double bond part. The epoxidized diene rubber of the present invention is a styrene-conjugated diene block copolymer such as polystyrene-polybutadiene block copolymer, polystyrene-polyisoprene block copolymer, polystyrene-polybutadiene-polyisoprene block copolymer. The carbon-carbon double bond portion possessed may be epoxidized.

The epoxidized diene rubber (A) is characterized by containing an epoxy group in the range of 0.15 to 7 meq / g and a number average molecular weight in the range of 10,000 to 100,000. The more preferable range of the epoxy value of the epoxidized diene rubber (A) is 0.5 to 4 meq / g, and the preferable number average molecular weight is in the range of 13,000 to 80000, more preferably in the range of 15000 to 70000. . When the epoxy value of the epoxidized diene rubber (A) is lower than 0.15 meq / g, the adhesiveness when adhering the crosslinkable rubber composition of the present invention to an adherend (metal, glass, etc.) decreases. On the other hand, when the epoxy value is higher than 7 meq / g, the affinity between the resulting crosslinkable rubber composition and the oil is lowered, and in particular, the adhesion to the oil surface-treated metal plate is deteriorated. In addition, when the number average molecular weight is lower than 10,000, the mechanical properties of the cross-linked product obtained by cross-linking the resulting cross-linkable rubber composition are greatly reduced. Processability at the time of preparing the rubber composition is deteriorated.
In addition, the number average molecular weight in this specification means the number average molecular weight of polystyrene conversion measured by gel permeation chromatography (GPC).

  As the epoxidized diene rubber (A), one obtained by epoxidizing one of the above-described diene rubber or styrene-conjugated diene block copolymer may be used alone, or two or more of them may be epoxidized. Those may be mixed and used as the epoxidized diene rubber (A).

  The production method of the diene rubber or styrene-conjugated diene block copolymer used as a raw material for the epoxidized diene rubber (A) is not particularly limited, and for example, an anionic polymerization method can be employed. In that case, an alkali metal such as metallic sodium or metallic lithium in an inert gas atmosphere such as argon or nitrogen in a solvent inert to the polymerization reaction such as hexane, cyclohexane, benzene or toluene; methyllithium or ethyllithium , N-butyllithium, alkyllithium compounds such as s-butyllithium, etc., as an initiator, and usually by polymerization in a polymerization temperature range of −100 to 100 ° C. and a polymerization time range of 0.01 to 200 hours. It can be carried out.

  Next, the carbon-carbon double bond portion of the molecular main chain of the obtained diene rubber or styrene-conjugated diene block copolymer is epoxidized to obtain an epoxidized diene rubber (A). The method for epoxidation is not particularly limited. For example, (i) a method of treating with a peracid such as peracetic acid (see JP-A-8-134135), (ii) a method of treating with a molybdenum complex and t-butyl hydroperoxide. (See Journal of Chemical Society, Chemical Communications (J. Chem. Soc., Chem. Commun.), Page 1686 (1989)), (iii) A method of treating with a tungstic acid catalyst and hydrogen peroxide ( Journal of Polymer Science, C (see J. Polym. Sci., C.) 28, 285 (1990)), (iv) tungsten compounds selected from ammonium tungstate or phosphotungstic acid, 4th Treatment with quaternary ammonium salt, phosphoric acid and hydrogen peroxide solution See JP 2002-249516) and the like.

  The site to be epoxidized is not particularly limited, and an epoxy group may be randomly introduced into the molecular chain of the diene rubber or styrene-conjugated diene block copolymer, or derived from a specific site such as isoprene. It is also possible to selectively epoxidize the carbon-carbon double bond moiety. For example, when a polyisoprene polymer block of a polybutadiene-polyisoprene diblock copolymer is selectively epoxidized, an epoxidized diene rubber (A) having a terminal block portion epoxidized can be obtained.

  The solid rubber (B), which is a component of the crosslinkable rubber composition of the present invention, is not particularly limited as long as it can be crosslinked by the crosslinking agent (D). For example, natural rubber (NR), polyisoprene rubber ( IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), styrene-isoprene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, chloroprene rubber, ethylene propylene diene rubber (EPDM), butyl rubber (IIR) and the like. Further, as the solid rubber, the above-described rubber may be used alone, or two or more kinds may be used in combination.

  The compounding amount of the solid rubber (B) is in the range of 0.1 to 300 parts by mass, more preferably in the range of 1 to 250 parts by mass, with respect to 100 parts by mass of the epoxidized diene rubber (A). More preferably, it is the range of 5-200 mass parts. When the blending amount of the solid rubber (B) is less than 0.1 parts by mass with respect to 100 parts by mass of the epoxidized diene rubber (A), the strength after crosslinking of the resulting crosslinkable rubber composition decreases, On the other hand, when the amount is more than 300 parts by mass, the viscosity of the crosslinkable rubber composition is increased and workability is deteriorated.

  As the filler (C) that is a constituent of the crosslinkable rubber composition of the present invention, those conventionally used as fillers for rubber can be used without particular limitation, such as channel black, furnace black, acetylene black, Carbon black such as thermal black; dry method white carbon, wet method white carbon, synthetic silicate white carbon, colloidal silica, precipitated silica, etc .; light calcium carbonate, heavy calcium carbonate, clay, talc, diatomaceous earth, mica And inorganic fillers such as magnesium hydroxide, barium sulfate, aluminum sulfate, calcium sulfate, graphite, and glass fiber. In addition, the above-mentioned filler (C) may be used independently and may be used in combination of 2 or more type.

  The blending amount of the filler (C) is in the range of 0.1 to 1500 parts by mass and more preferably in the range of 1 to 1400 parts by mass with respect to 100 parts by mass of the epoxidized diene rubber (A). More preferably, it is in the range of 5 to 1300 parts by mass. When the blending amount of the filler (C) is less than 0.1 parts by mass with respect to 100 parts by mass of the epoxidized diene rubber (A), the strength after crosslinking of the resulting crosslinkable rubber composition decreases, On the other hand, when the amount is more than 1500 parts by mass, the viscosity of the crosslinkable rubber composition is increased and workability is deteriorated.

  As the crosslinking agent (D) which is a constituent component of the crosslinkable rubber composition of the present invention, those usually used for rubber crosslinking can be used without particular limitation, and examples thereof include sulfur, morpholine disulfide, alkylphenol disulfide and the like. Sulfur crosslinking agent; cyclohexanone peroxide, methyl acetoacetate peroxide, t-butyl peroxyisobutyrate, t-butyl peroxybenzoate, benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, di-t-butyl peroxide, Examples thereof include organic peroxide crosslinking agents such as 1,3-bis (t-butylperoxyisopropyl) benzene.

  The compounding quantity of a crosslinking agent (D) is the range of 0.1-50 mass parts with respect to 100 mass parts of epoxidized diene rubber (A), and it is more the range of 0.1-45 mass parts. Preferably, it is 0.1-40 mass parts. When the blending amount of the crosslinking agent (D) is less than 0.1 parts by mass with respect to 100 parts by mass of the epoxidized diene rubber (A), the strength after crosslinking of the resulting crosslinkable rubber composition decreases, On the other hand, when the amount is more than 50 parts by mass, the flexibility after crosslinking of the crosslinkable rubber composition is impaired, and the storage stability of the crosslinkable rubber composition is deteriorated.

  In the crosslinkable rubber composition of the present invention, a crosslinking accelerator or a crosslinking aid may be blended as necessary. Such a crosslinking accelerator or crosslinking aid is not particularly limited, and can be appropriately selected and used depending on the crosslinking agent to be used. Examples of the crosslinking accelerator include thiuram accelerators such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide and tetraethylthiuram disulfide; thiazole accelerators such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide; N-cyclohexyl-2 Sulfenamide accelerators such as benzothiazylsulfenamide and N-oxydiethylene-2-benzothiazolylsulfenamide; guanidine accelerators such as diphenylguanidine and diortolylguanidine; n-butyraldehyde -An aldehyde-amine accelerator such as an aniline condensate and butyraldehyde-monobutylamine condensate; an aldehyde-ammonia accelerator such as hexamethylenetetramine; a thiourea accelerator such as thiocarbanilide And the like. When blending these crosslinking accelerators, one type may be used alone, or two or more types may be used in combination.

  Moreover, as a crosslinking aid, metal oxides such as zinc oxide and magnesium oxide; metal hydroxides such as calcium hydroxide; metal carbonates such as zinc carbonate and basic zinc carbonate; fatty acids such as stearic acid and oleic acid; Aliphatic metal salts such as zinc stearate and magnesium stearate; amines such as di-n-butylamine and dicyclohexylamine; ethylene dimethacrylate, diallyl phthalate, N, Nm-phenylene dimaleimide, triallyl isocyanurate, trimethylol Examples include propane trimethacrylate. When blending these crosslinking aids, one type may be used alone, or two or more types may be used in combination.

  Moreover, you may mix | blend a foaming agent with the crosslinkable rubber composition of this invention as needed. Such a foaming agent is not particularly limited, and examples thereof include sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, azodicarbonamide, azobisisobutyronitrile, barium azodicarboxylate, and the like. When blending these foaming agents, one type may be used alone, or two or more types may be used in combination.

  Further, the crosslinkable rubber composition of the present invention includes various compounding agents such as an anti-aging agent, a plasticizer, a silane coupling agent, a light stabilizer, an antibacterial agent, a flame retardant, and a pigment within a range that does not impair the characteristics. Furthermore, it can also mix | blend.

  The crosslinkable rubber composition of the present invention can be produced by applying a method generally used as a method for producing a rubber composition. For example, a predetermined amount of epoxidized diene rubber (A), solid rubber (B), filler (C), cross-linking agent (D) and other additives as required is used using a Brabender, Banbury mixer or the like. It is obtained by mixing.

  The crosslinkable rubber composition obtained above can be crosslinked, for example, by hot pressing with a press molding machine, or by crosslinking with a mold, to obtain a crosslinked product.

  The crosslinkable rubber composition of the present invention is excellent in workability at the time of application, and has excellent rubber elasticity after heat crosslinking, so that it can be suitably used as a sealing material for automobile bodies and building materials.

  Hereinafter, the present invention will be specifically described with reference to Examples. In addition, this invention is not limited at all by these Examples.

Reference example 1
<1> 2000 g of hexane and 2.5 g of n-butyllithium were charged in an autoclave having a capacity of 5 liters subjected to nitrogen substitution, and then the temperature was raised to 50 ° C., 650 g of isoprene was added, and polymerization was performed for 3 hours. . When a part of the reaction solution was sampled and the product was analyzed by GPC, polyisoprene having a number average molecular weight (Mn) = 27,000 in terms of polystyrene and a molecular weight distribution (Mw / Mn) = 1.16 was produced.
<2> After washing 300 g of the polymerization reaction solution obtained in the above <1> with water, it was charged into a 1 liter autoclave, 0.16 g of phosphotungstic acid, 0.15 g of phosphoric acid, 13 g of 35% by mass aqueous hydrogen peroxide solution 90 g of water and 0.26 g of trioctylmethylammonium chloride were added and reacted at 80 ° C. for 3 hours. The obtained reaction solution was poured into methanol to reprecipitate the polymer, filtered, and vacuum-dried at 80 ° C. for 7 hours to obtain 70 g of epoxidized polyisoprene (hereinafter abbreviated as e-IR-1). Got. When obtained e-IR-1 was analyzed by GPC, it was Mn = 27600 and Mw / Mn = 1.16. Further, about 0.5 g of e-IR-1 was precisely weighed and dissolved in 10 ml of tetrahydrofuran (THF) at 25 ° C., 10 ml of 0.2N hydrochloric acid in THF was added to this solution, and the mixture was stirred for 30 minutes. After reacting with the epoxy group in -1, the excess of hydrochloric acid was titrated with 0.1N potassium hydroxide ethanol solution to measure the epoxy value (hereinafter, this method is referred to as hydrochloric acid back titration method). It was 1.5 meq / g.

Reference example 2
After washing 300 g of the polyisoprene polymerization reaction solution obtained in the same manner as in <1> of Reference Example 1 with water, it was charged into a 1 liter autoclave and phosphotungstic acid 0.48 g, phosphoric acid 0.45 g, 35 A 39% by mass aqueous hydrogen peroxide solution, 90 g of water and 0.78 g of trioctylmethylammonium chloride were added and reacted at 80 ° C. for 3 hours. The obtained reaction solution was poured into methanol to reprecipitate the polymer, filtered, and vacuum dried at 80 ° C. for 7 hours to obtain 70 g of epoxidized polyisoprene (hereinafter abbreviated as e-IR-2). Got. When the obtained e-IR-2 was analyzed by GPC, it was Mn = 27900 and Mw / Mn = 1.16. Moreover, it was 3.6 meq / g when the epoxy value was measured by the hydrochloric acid back titration method similarly to <2> of Reference Example 1.

Reference example 3
The polyisoprene polymerization reaction solution obtained by the same operation as in <1> of Reference Example 1 was washed with water and then vacuum dried at 80 ° C. for 7 hours to obtain polyisoprene. 200 g of the obtained polyisoprene was charged into a 1 liter autoclave, 3 g of maleic anhydride was added, and the mixture was reacted at 180 ° C. for 15 hours to obtain maleic anhydride-modified polyisoprene (hereinafter abbreviated as MAn-IP). It was. When the obtained MAn-IP was analyzed by GPC, Mn = 33000 and Mw / Mn = 1.28.

Examples 1-2
Epoxidized polyisoprene (e-IR-1, e-IR-2), butadiene rubber (trade name “Diene NF35R”, manufactured by Asahi Kasei Co., Ltd.) obtained by the method of Reference Examples 1 and 2, and calcium carbonate (trade name “ “Shiraka Hana CCR” (manufactured by Shiraishi Kogyo), zinc oxide, stearic acid, sulfur, and anti-aging agent [trade name “NOCRACK NS-6” (2,2′-methylene-bis (4-methyl-6-tert-butylphenol) ), Manufactured by Ouchi Shinsei Co., Ltd.], naphthenic oil (trade name “Sunthene 250”, manufactured by Sunoco, Inc.) at a blending ratio shown in Table 1 and setting the Brabender at 50 ° C. and kneading for 10 minutes. Next, cross-linking accelerators [trade name “Noxeller DM” (dibenzothiazyl disulfide), trade name “Noxeller DT” (diortolyl guanidine), both manufactured by Ouchi Shinsei Co., Ltd.] are used at the blending ratio shown in Table 1. Added and kneaded for 3 minutes. The obtained crosslinkable rubber composition was applied to a steel plate having a width of 25 mm and a thickness of 1 mm (SPCC as defined in JIS G 3141, cold rolled steel plate) with a width of 25 mm, and the same material was passed through a spacer having a thickness of 1.5 mm. The steel plates were stacked. Further, as shown in FIG. 1, a support made of the same material as that of the steel plate was attached, and after heat crosslinking at 140 ° C. for 20 minutes, the spacer was removed to obtain a test piece. Next, in accordance with JIS K 6830, the support portions at both ends are gripped and pulled in the 180 ° direction, and the maximum load (N) applied until the steel sheet and the crosslinkable rubber composition are peeled off is measured. Say it. A similar test was performed using an aluminum plate (A1050P specified in JIS H 4000, an aluminum plate having a thickness of 1.0 mm) and a glass plate (borosilicate glass, thickness 1.5 mm) as adherends. . The results are also shown in Table 1.

Comparative Example 1
Except that the polyisoprene obtained in <1> of Reference Example 1 was used in place of the epoxidized polyisoprene in Examples 1-2, the same operation as in Examples 1-2 was performed to obtain a crosslinkable rubber composition. It was. Table 1 shows the evaluation results obtained in the same manner as in Examples 1 and 2.

Comparative Example 2
Except having used MAn-IP obtained in Reference Example 3 in place of epoxidized polyisoprene in Examples 1-2, the same operation as in Examples 1-2 was performed to obtain a crosslinkable rubber composition. Table 1 shows the evaluation results obtained in the same manner as in Examples 1 and 2.

Comparative Example 3
In Examples 1-2, epoxidized polybutadiene instead of epoxidized polyisoprene: trade name “Epolide PB3600” (manufactured by Daicel Chemical Industries, Ltd., Mn = 5600, Mw = 19300 (both Mn and Mw are values in terms of polystyrene), epoxy A crosslinkable rubber composition was obtained by performing the same operation as in Examples 1 and 2 except that the valence of 4.8 meq / g) was used. Table 1 shows the evaluation results obtained in the same manner as in Examples 1 and 2.

From Table 1, it can be seen that the crosslinkable rubber compositions obtained in Examples 1 and 2 have improved adhesion to steel plates, aluminum plates, and glass plates than the crosslinkable rubber compositions obtained in Comparative Example 1. .
On the other hand, when maleic anhydride-modified polyisoprene is used as in Comparative Example 2, crosslinking proceeds during kneading and solidifies so that it cannot be applied to the adherend, and the adhesion strength can be evaluated. could not. Further, when a commercially available epoxidized polybutadiene was used as in Comparative Example 3, the rubber component and the oil were separated, and a good sealing material could not be obtained, so the adhesion strength could not be evaluated.
As described above, the crosslinkable rubber composition of the present invention in which the epoxidized diene rubber (A) having a specific range of molecular weight and epoxy value is blended does not crosslink epoxy groups with additives such as a crosslinking aid. Low viscosity and good wettability to metals and glass. In addition, since the epoxidized diene rubber (A) has ether oxygen (epoxy group) having high affinity with metal or glass in the molecule, adhesion to the metal or glass is improved.

  The crosslinkable rubber composition of the present invention is excellent in workability at the time of application, and has excellent rubber elasticity after heat crosslinking, so that it can be suitably used as a sealing material for automobile bodies and building materials.

It represents the positional relationship between the adherend (steel plate, aluminum plate or glass) and the crosslinkable rubber composition when evaluating the adhesive strength of the crosslinkable rubber compositions obtained in Examples and Comparative Examples. . DESCRIPTION OF SYMBOLS 1 Adhering body (steel plate, aluminum plate or glass) 2 Crosslinkable rubber composition 3 Spacer 4 Support body (same material as adherend)

Claims (3)

(A) For 100 parts by mass of an epoxidized diene rubber having an epoxy group in the range of 0.15 to 7 meq / g and a number average molecular weight of 10,000 to 100,000, (B) a solid rubber Of 0.1 to 300 parts by weight, (C) 0.1 to 1500 parts by weight of filler, and (D) 0.1 to 50 parts by weight of crosslinking agent. Rubber composition. The epoxidized diene rubber (A) is composed of isoprene; butadiene; a mixture of isoprene and butadiene; a mixture of isoprene and styrene; a mixture of butadiene and styrene; a mixture of butadiene, isoprene and styrene; 2. The crosslinkable rubber composition according to claim 1, which is obtained by epoxidizing a carbon-carbon double bond of a polymer. A sealing material, wherein the crosslinkable rubber composition according to claim 1 or 2 is used.

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