| 摘要 |
PURPOSE:To obtain the title composition which is excellent in moldability and can give a vulcanized molding excellent in heat resistance, low-temperature resistance, oil resistance, friction resistance, abrasion resistance, and dimensional accuracy, by mixing a millable urethane elastomer or its components with a specified prepolymer and a crosslinking agent. CONSTITUTION:Either a commercially avilable millable urethane elastomer (a) or a mixture (b) of its components comprising a polyol component (1) such as polyester-polyol of an MW of 500-3,000, a diisocyanate (2) such as 4,4'- diphenylmethane diisocyanate and a chain extender (3) such as 1,4-butanediol is mixed with 5-30pts.wt. prepolymer (B), as an additive, obtained by reacting a polyol comprising polydimethylsiloxanediol of a weight-average MW of 1,000-3,000 with component (b), and the optimal amount of a crosslinking agent (c) comprising an organic peroxide (e.g., dicumyl peroxide), etc.
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