JP2950200B2 - Rubber laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vulcanized rubber composition layer selected from epichlorohydrin rubber or nitrile rubber and a vulcanized rubber composition layer of a chlorinated polyethylene and a nitrile rubber, which is strongly vulcanized and adhered. The present invention relates to a rubber laminate and is suitable for, for example, a multilayer hose for an automobile.

[0002]

2. Description of the Related Art In order to obtain a rubber laminate, it is common practice to vulcanize and bond two types of rubber having different characteristics. That is, a laminate of rubber having heat resistance and weather resistance and rubber having oil resistance is a laminate having both properties, but if the adhesion between the rubbers is not good,
Practical problems arise. For example, a two-layer hose in which the outer layer is made of a laminate of chlorinated polyethylene and the inner layer of epichlorohydrin rubber can be a hose having both the weather resistance of chlorinated polyethylene and the oil resistance of epichlorohydrin rubber, but these laminates are usually used. It is known that vulcanization adhesion is not good. A method for improving the adhesive strength of the laminate has been proposed by the present applicant (JP-A-63-12).
8047), however, in that method, the chlorinated polyethylene composition adheres well only to the rubber composition containing the specific vulcanizing agent,
When the vulcanizing agent of the rubber composition of the adherend is different, there is a problem that the adhesive strength is reduced.

[0003]

In view of the above, the present inventors have developed a laminate having good adhesion to epichlorohydrin rubber or nitrile rubber without impairing the heat resistance and weather resistance of chlorinated polyethylene. As a result of intensive research for the purpose of obtaining, a vulcanizing rubber composition obtained by adding a specific vulcanizing agent to a blend rubber of chlorinated polyethylene and nitrile rubber and a vulcanizing rubber selected from epichlorohydrin rubber and nitrile rubber It has been found that a laminate of the composition has good vulcanization adhesion.

It is known that the above vulcanized composition for a blended rubber can be obtained as a vulcanized composition having an additive property according to the ratio of each rubber (Japanese Patent Publication No. 59-23579). ) Is not known to use this blend rubber in a laminate with epichlorohydrin rubber or nitrile rubber.

[0005]

According to the present invention, a blend rubber of a chlorinated polyethylene and a nitrile rubber is provided with the following (a) to
A rubber laminate comprising a vulcanizing rubber composition containing the vulcanizing agent (d) and a vulcanizing rubber composition containing a rubber selected from epichlorohydrin-based rubber and nitrile rubber, which are vulcanized and adhered. is there. (A) sulfur (b) trithiocyanuric acid (c) thiuram sulfides, aliphatic amines having 5 to 20 carbon atoms having a boiling point of about 110 ° C. or higher, organic acid salts of amines, diarylguanidine, condensation of aniline with aldehyde Product, one or two selected from 2-benzothiazylsulfenamides of primary or secondary amines;
(D) Group IIA metal compound of the periodic table

The chlorinated polyethylene used in the present invention refers to a polyethylene homopolymer or a monomer which can be copolymerized with ethylene such as propylene, 1-butene, vinyl acetate or ethyl acetate as an auxiliary component. Chlorinated copolymer means substantially amorphous chlorinated polyethylene having a chlorine content of 30 to 45% by weight. If the chlorine content exceeds 45% by weight, the rubber elasticity decreases. If the amount is less than 30% by weight, the adhesive strength after immersion in the lubricating oil decreases.

The nitrile rubber for blending with chlorinated polyethylene used in the present invention includes NBR comprising a binary copolymer of acrylonitrile and butadiene, and NBR and acrylate copolymer obtained by copolymerizing an antioxidant component. In addition to nitrile rubbers selected from NBR, blends of these nitrile rubbers and polyvinyl chloride are also included. These nitrile rubbers may be used alone or as a mixture. The acrylonitrile content in the nitrile rubber used here is preferably 20 to 40% by weight. If the acrylonitrile content is outside this range, the adhesion to the epichlorohydrin rubber or the nitrile rubber layer will be reduced.

In the present invention, the blend ratio of the chlorinated polyethylene to the nitrile rubber is as follows:
When the content is 8 to 60% by weight, preferably 95 to 70% by weight, the nitrile rubber is 2 to 40% by weight, preferably 5 to 30% by weight, and the chlorinated polyethylene is 98% by weight or more, the adhesive strength to epichlorohydrin or nitrile rubber is sufficient. If it is less than 60% by weight, various properties such as ozone resistance of the blended rubber deteriorate. The thiuram sulfide used in the present invention is a compound represented by the following general formula (I).

[0009]

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In the formula (I), R ¹ and R ² or R ³ and R ⁴ may be the same or different, or R ¹ and R ² or R ³ and R ⁴ are bonded to each other. And a group forming a ring. For example, an alkyl group, an aryl group, a cycloalkyl group, a heterocyclic ring, or the like can be given. x is a positive integer satisfying 1 ≦ x ≦ 6.

Specific examples of these thiuram sulfides include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram monosulfide, tetrabutylthiuram disulfide, N, N'-dimethyl-N, N '
-Diphenylthiuram disulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide and the like.

The aliphatic amine having a boiling point of about 110 ° C. or higher in the present invention is an aliphatic or cycloaliphatic primary, secondary or tertiary amine having 5 to 20 carbon atoms and having a pK value of about 110 or less. 4.5 or less is preferred. Representative examples of such amines include n-hexylamine, octylamine, dibutylamine, tributylamine, trioctylamine, di (2-ethylhexyl) amine, dicyclohexylamine, hexamethylenediamine, and the like. .

The organic acid salt of an amine is preferably a salt of an amine having a pK value of about 4.5 or less and an organic acid having a pK value of about 2.0 or more. Representative examples of such an organic acid salt of an amine include n-butylamine acetate, dibutylamine oleate, hexamethylenediamine carbamate, and dicyclohexylamine salt of 2-mercaptobenzothiazole. . Examples of the diarylguanidine in the present invention include basic amine compounds such as diphenylguanidine and ditolylguanidine.

The condensation product of aniline and aldehyde includes aniline and at least one kind of carbon having 1 to 7 carbon atoms.
Condensates with aldehydes are preferred. As a specific example,
There are condensates of aniline and butyraldehyde aldehyde.
The primary or secondary amine 2-benzothiazylsulfenamide of the present invention is represented by the following general formula (II).

[0015]

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However, in the formula (II), R ⁵ and R ⁶ are
May be the same or different, and have 1 to 1 carbon atoms selected from hydrogen, an alkyl group, a cycloalkyl group, and an aralkyl group.
And is a group having no substituent containing a hetero atom. R ⁵ and R ⁶ are not both hydrogen.

The primary or secondary amine which forms the above-mentioned sulfenamide preferably has a pK value of about 4.5 or less, and specific examples thereof include cyclohexylamine, butylamines, diethylamine and dipropylamine. , Dioctylamines, dilaurylamines, dicyclohexylamine, piperidine, pipecoline, morpholine, piperazine and the like.

The Group IIA metal compound used in the present invention includes oxides, hydroxides, carbonates, carboxylates, silicates, phosphites and borates. Typical examples thereof include magnesia, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, calcium silicate, calcium stearate, magnesium phosphite and the like.

In the present invention, in addition to the above-mentioned vulcanizing agents, various reinforcing agents and fillers necessary for adjusting various practical properties are added to the blended rubber of chlorinated polyethylene and nitrile rubber.
A plasticizer, a processing aid, a stabilizer, an antioxidant, an ultraviolet absorber, a pigment, a flame retardant, a foaming agent and the like can be arbitrarily compounded.

The rubber component in the epichlorohydrin rubber composition for lamination used in the present invention includes epichlorohydrin homopolymer, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether Refers to a rubber selected from terpolymers. In the case of copolymer rubber, its composition ratio (mol)
Are from 85 to 99:15 to 1 in the case of an epichlorohydrin-allyl glycidyl ether copolymer and from 20 to 8 in the case of an epichlorohydrin-ethylene oxide copolymer.
0: 80-20, in the case of an epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer,
20-79: 79-20: 1-20 are preferred. These rubbers may be used alone or as a mixture.

The rubber component in the nitrile rubber composition for lamination used in the present invention includes NBR composed of a binary copolymer of acrylonitrile and butadiene, NBR obtained by copolymerizing an antioxidant component, acrylate copolymerized NBR,
It refers to a nitrile rubber selected from a blend of polyvinyl chloride and a nitrile rubber, and a hydrogenated nitrile rubber, and these rubbers may be used alone or as a mixture.

The above epichlorohydrin rubber or nitrile rubber composition contains a vulcanizing agent, a vulcanization accelerator, a vulcanization retarder necessary for vulcanization of each rubber, and a vulcanizing agent necessary for processing.
Alternatively, various reinforcing agents, fillers, plasticizers, processing aids, stabilizers, anti-aging agents necessary for adjustment of practical physical properties,
An ultraviolet absorber, a pigment, a flame retardant, a foaming agent and the like can be arbitrarily compounded.

In the present invention, the blended rubber composition of chlorinated polyethylene and nitrile rubber, the epichlorohydrin rubber composition, and the method of mixing the nitrile rubber composition may be any of those conventionally used in the field of rubber processing. For example, a mixing roll, a Banbury mixer, various kneaders, and the like can be used.

The vulcanization adhesion is usually 0.02 mm to 10 mm in thickness.
mm of both unvulcanized rubber sheets, 100-250
C. by heating for 1 to 300 minutes. Specifically, after the laminate is manufactured by an extruder, an injection molding machine, a transfer molding machine, or by any method such as simply superimposing both unvulcanized rubber sheets directly, or by heating at the same time as the production, the cross-linking is performed. Molded. As a heating method, any heating method using electric heating, steam, hot air, infrared rays, microwaves or the like can be used.

[0025]

The present invention will be described below with reference to examples. In the examples,% is based on weight. The following chlorinated polyethylene (1)
To (4), nitrile rubbers (5) to (10), kneaded with a mixing roll at 60 ° C. for 15 minutes into a sheet with the composition shown in Table 1 and put into a mold at 160 ° C., 80 kg
/ Cm ² for 25 minutes to obtain a sheet having a thickness of 2 mm. Each of the obtained vulcanized compositions was subjected to a physical property test according to JIS K6301, and the results are shown in Table 3.

Chlorinated polyethylene (1): Chlorine content 40%, ML130 manufactured by Daiso Corporation MR104 Chlorinated polyethylene (2): Chlorine content 35%, ML125 manufactured by Daiso Corporation H135 Chlorinated polyethylene (3): Chlorine content 30%, ML125 Daiso Co., Ltd. N130 Chlorinated polyethylene (4): 25% chlorine content, ML120 Daiso Co., Ltd. trial product Nitrile rubber (5): Acrylonitrile content 48%, ML45 Nippon Synthetic Rubber Co., Ltd. N215SL Nitrile rubber (6): 35% acrylonitrile content, ML55 N230S nitrile rubber manufactured by Nippon Synthetic Rubber Co., Ltd. (7): 26% acrylonitrile content, ML55 N240S nitrile rubber manufactured by Nippon Synthetic Rubber Co., Ltd. (8): 20% acrylonitrile content , ML65 Nippon Synthetic Rubber Co., Ltd. N250S nitrile rubber (9): acrylonitrile content 15%, ML60 manufactured by Nippon Synthetic Rubber Co., Ltd. N260S nitrile rubber (10): NBR / PVC blend (70/30%) acrylonitrile content 20%, ML70 manufactured by Nippon Synthetic Rubber Co., Ltd. NV75

[0027]

[Table 1]

Next, each of the sheets A having a thickness of about 2 mm was obtained by kneading the mixture of each Example shown in Table 1 with a mixing roll at 60 ° C. for 15 minutes. Similarly, the following (11) to
The epichlorohydrin-based rubber or nitrile-based rubber of (13) was kneaded with the composition shown in Table 2 to obtain each sheet B having a thickness of about 2 mm. Then, the above sheets A and B were superimposed, placed in a mold and pressed at 160 ° C. and 80 kg / cm ² for 25 minutes to obtain a vulcanized rubber laminate having a thickness of 4 mm. A rectangular test piece having a width of 25 mm and a length of 100 mm was cut out from the obtained laminate, and the adhesive strength was measured at a moving speed of 50 mm / min for gripping the test piece in accordance with JIS K6301, and the results are shown in Table 4.

Epichlorohydrin rubber (11): terpolymer of epichlorohydrin-ethylene oxide-allyl glycidyl ether-tereyl, ML55 Daiso Co., Ltd. Epichromer CG nitrile rubber (12): acrylonitrile content 35%, ML55 Nippon Synthetic Rubber Co., Ltd. N230S Hydrogenated nitrile rubber (13): acrylonitrile content 36%, ML75, Zptol 2020 manufactured by Zeon Corporation

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

[0033]

According to the present invention, a vulcanizing rubber composition containing a blend rubber of chlorinated polyethylene and nitrile rubber, and a vulcanizing rubber composition containing a rubber selected from epichlorohydrin rubber and nitrile rubber. Is strongly vulcanized and bonded to obtain a rubber laminate.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 C08J 5/12

Claims (2)

(57) [Claims] 1. A vulcanizing rubber composition comprising the following vulcanizing agents (a) to (d) blended in a blend rubber of chlorinated polyethylene and nitrile rubber, and epichlorohydrin rubber and nitrile rubber. A rubber laminate comprising a rubber composition for vulcanization and a rubber, which is vulcanized and bonded. (A) sulfur (b) trithiocyanuric acid (c) thiuram sulfides, aliphatic amines having 5 to 20 carbon atoms having a boiling point of about 110 ° C. or higher, organic acid salts of amines, diarylguanidine, condensation of aniline with aldehyde Product, one or two selected from 2-benzothiazylsulfenamides of primary or secondary amines;
(D) Group IIA metal compound of the periodic table 2. A blend rubber comprising 98 to 60% by weight of chlorinated polyethylene having a chlorine content of 30 to 45% by weight, and a nitrile rubber having a acrylonitrile content of 20 to 40% by weight.
The laminate according to claim 1, which is a blend rubber with 40% by weight.