| 摘要 |
PURPOSE:To provide a cement compsn. having an improved bonding strength before and after vulcanization, prepared by adding a specified amount of carbon master batch in powder contg. non-oil-extended macromolecular SBR as rubber component, to a raw material rubber. CONSTITUTION:The cement compsn. is prepared by adding carbon master batch in powder which contains non-oil-extended styrene/butadiene rubber (SBR) having a weight-average M.W. of 500,000 or higher to a raw material rubber in an amt. of 5pts.wt. or higher as rubber. For higher self-adhesiveness and bonding strength, the SBR should pref. have a weight-average M.W. of about 1,500,000-1,600,000 and an M.W. distribution which is broader on the higher M.W. side. It is preferable that the carbon master batch in powder contain 40-120pts.wt. carbon black per 100pts.wt. non-oil-extended macromolecular SBR.
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