JP3293177B2 - Chloroprene rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chloroprene rubber composition. More specifically, the present invention relates to a chloroprene rubber composition suitably used for forming a dust cover incorporated in a ball joint.

[0002]

2. Description of the Related Art Normally, the surface of a vulcanized molded product of rubber is 1.0
It has the above friction coefficient. Similarly, the vulcanized molded product of chloroprene rubber used for dust covers incorporated in ball joints has a large coefficient of friction.When a chloroprene rubber dust cover is incorporated in a ball joint, the lip of the dust cover and the ball joint There is a problem that the sliding resistance between the shaft or the skirt portion (fixed portion) of the dust cover and the ball seat of the ball joint is large, and the assembling property is poor.

[0003] If the assembling property is poor, it is difficult to automate the assembling, and it is not possible to improve the productivity of the ball joint. In order to solve such problems, paraffin, higher fatty acid amide, polyethylene wax, etc. are blended in the chloroprene rubber composition and bleed them on the rubber surface of the vulcanized molded product, so that the frictional resistance of the rubber surface is reduced. Has been adopted, but it is not possible to achieve its purpose sufficiently, or it blooms on the surface in the state of the cloth before vulcanization, and vulcanization adhesion with metals and resin molded products Problems such as lowering

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vulcanization molding having an improved vulcanization adhesion and a surface friction coefficient, which is suitably used for molding a dust cover incorporated in a ball joint. An object of the present invention is to provide a chloroprene rubber composition capable of giving a product.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
This is achieved by a chloroprene rubber composition in which a silicone oil having a phenyl group in a molecule is added to the chloroprene rubber.

[0006] As the silicone oil having a phenyl group in the molecule, an oily polymer which is a polysiloxane having a terminal blocked with an alkyl group and has at least one phenyl group in a monomer unit is used. This phenyl silicone oil has a viscosity (25 ° C.) of about 50 to 10,000 cst, preferably about 100 to 1000 cst, and is preferably chloroprene rubber 100.
It is used in an amount of about 0.5 to 10 parts by weight, preferably about 1 to 5 parts by weight, based on parts by weight. If the addition ratio is less than this, the intended purpose of the present invention is not achieved, while if it is added at a higher ratio, the strength, adhesiveness, workability, and the like are undesirably deteriorated.

The composition is prepared by adding various compounding agents and phenyl silicone oil generally used to chloroprene rubber and kneading them with an open roll or the like, and vulcanizing the mixture. This is performed according to general vulcanization conditions for chloroprene rubber.

[0008]

By adding silicone oil having a phenyl group in the molecule to chloroprene rubber, the rubber surface friction coefficient of the vulcanized molded product can be significantly reduced. Moreover, the vulcanization adhesion to metals and the like is good. Therefore, chloroprene rubber composition of the present invention, das
The dust cover which is suitably used for molding the cover and has good incorporation into a ball joint due to a low surface friction coefficient.

[0009]

Next, the present invention will be described with reference to examples.

Examples 1 to 3 100 parts by weight of chloroprene rubber (Denka chloroprene electrochemical product DCR31) FEF carbon black 45 (Showa Black N550G from Showa Cabot) Antioxidant IPPD 2 (Ouchi Shinko Chemical Nocrack 810NA) Magnesium oxide 4 (Kamijima Chemical Starmag U) Zinc Oxide 5 (Shodo Chemical Zinchua Special Number) Stearic Acid 1 (Miyoshi Oil / Fat Product Stearic Acid TST) 2-Mercaptoimidazole 1 (Bayer Vulkatit NPV / C) Tetramethylthiuram Disulfide 1 (Ouchi Emerging Chemical Noxeller TT-P) methylphenyl silicone oil 2 (Example 1) (Shin-Etsu Chemical KF54; viscosity 400 cst) 5 (Example 2) 10 (Example 3)

Each of the above components was kneaded with an open roll at 60 to 70 ° C., and was molded under pressure at 150 ° C., 10 MPa for 30 minutes. (Measurement items) Rubber surface friction coefficient: HEIDON-14 manufactured by HEIDON Measured at a sliding speed of 50 mm / min under a load of 50 g Adhesion: 50% toluene solution of Chemrock 205 as an undercoat and Chemlock 252 as an overcoat on SPCC As applied,
After natural drying, heat and pressure are applied simultaneously with the kneaded material for vulcanization bonding, and the peel strength of the bonded surface and the residual rubber ratio (residual rubber after peeling) are measured

[0012] In Comparative Examples 1 to 10 Examples 1 to 3, in place of the methyl phenyl silicone oil, the following additives were used, respectively. Additive parts by weight No comparative example 0 1 Paraffin wax 5 2 (Nippon Petroleum Products 135 degree paraffin wax pellets) Dimethyl silicone oil 23 (Shin-Etsu Chemical KF96) 5 4 Oleic acid amide 2 5 (Nippon Kasei Chemicals Daiamide O) 5 6 Ethylene bisstearyl amide 10 7 (Lion Afuzo product armowax EBS-P) Stearyl amide 10 8 (Lion product armide HT-P) Polybutene 10 9 (Nippon Soda product polybutene 5H) Polyethylene wax 10 10 (Sanyo Chemical product sun wax 171P) )

The measurement results in the above Examples and Comparative Examples are shown in the following table. Table Example Surface friction coefficient Peel strength (KN / m) Rubber residual ratio Example 1 0.2 9.5 95 〃2 0.06 8.5 95 ３3 0.05 7.0 85 Comparative Example 1> 2.0 10.2 100 〃2 1.7 9.9 100 ３3 1.4 8.4 95 ４4 0.9 8.0 80 ５ 5 1.6 9.5 80 〃 6 0.6 9.3 70 ７ 7 1.0 8.4 75 ８ 8 1.0 8.1 80 ９ 9 1.4 7.2 80 〃 10 1.9 7.4 85

From the above results, the following can be said. (1) In each of Comparative Examples except Comparative Example 6, the friction coefficient of the rubber surface was not sufficiently reduced. (2) In Comparative Example 6, although the coefficient of friction decreases, the adhesiveness also decreases. (3) In each of the examples, the coefficient of friction is significantly reduced and the adhesiveness is sufficient.

Claims (2)

(57) [Claims] 1. A ball join comprising a chloroprene rubber and a silicone oil having a phenyl group in the molecule.
A chloroprene rubber composition used for molding a dust cover to be incorporated into a rubber cover . 2. The chloroprene rubber composition according to claim 1.
Vulcanized from, incorporated into a ball joint
Dust cover.