| 摘要 |
PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer which is excellent in the balance between hardness and mechanical strengths and gives a molding exhibiting very little surface bleeding by mixing specific polymers to obtain a mixture in a specified state. SOLUTION: This elastomer comprises an olefin copolymer rubber (A), a crystalline propylene copolymer modified with anα-olefin or polar groups (B), and anα-olefin-linear polyethylene (C), the three ingredients having been mixed homogeneously. In the elastomer, ingredient A is cross-linked with an org. peroxide; ingredient C is left uncross-linked; and particles of ingredient A are covered with ingredient B and then further with uncross-linked ingredient C. The elastomer is prepd. by homogeneously melt mixing ingredients A and B, adding an org. peroxide and a cross-linking aid to the resulting mixture, kneading it at the 5-min half-life temp. of the peroxide or higher, continuing kneading for several min after the kneading torque reaches the max., and adding ingredient C to and kneading it with the mixture.
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