| 摘要 |
PURPOSE:A liquid rubber composition, obtained by reacting a mixture of a hydrogenated hydroxyl-terminated 1,4- and 1,2-polybutadiene with a specific NCO compound, and incorporating an NCO compound and hydrated alumina, etc., and capable of giving a cured article having electrical insulating property and flame retardancy. CONSTITUTION:A liquid rubber composition obtained by adding 0.05-0.2 NCO equivalent, based on one hydroxyl group equivalent of a mixture prepared by adding 30-50pts.wt. hydrogenated hydroxyl-terminated-1,2-polybutadiene polymer having >=80% 1,2-bond of 2,000-5,000 molecular weight to 100pts.wt. hydrogenated hydroxyl-terminated-1,4-polybutadiene polymer having >=70% 1,4-bond of 2,000-5,000 molecular weight, NCO compound expressed by the formula (R1-R3 are lower alkyl; n is an integer 1-4) thereto, reacting them to give a prepolymer, adding 0.8-1.0 NCO equivalent, based on one hydroxyl group equivalent of the prepolymer, compound expressed by the formula thereto and incorporating 50-130pts.wt. hydrated alumina and 3-25pts.wt. magnesium hydroxide with the resultant mixture.
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