| 摘要 |
PURPOSE:The title foam low in heat sensitivity and excellent in sound-absorbing and vibration-proof performances, prepared by polymerizing and foaming an organic polyisocyanate and a polyol by a one-shot process in the presence of a blowing agent, a catalyst and a specified foam stabilizer. CONSTITUTION:A foam stabilizer (E) is obtained by mixing the following two copolymers (I) and (II) of the formula: a random dimethylsiloxane (a)/ oxyalkylenesiloxane (b) polymer (I) represented by the formula (wherein R is a random copolymer, average MW of 1,600-2,000, which comprises 75pts.wt. ethylene oxide and 25pts.wt. propylene oxide and whose end groups are capped with methoxy groups, m=4-8, n+m=43-53) and a random copolymer (II) which is quite the same as copolymer I except that R has an average MW of 200-500, m=11-22 and n+m=13-25 in the formula. An organic polyisocyanate (A) and a mixed (at least two) polyoxyalkylenepolyol (B) of a functionality of 2-3 and an average hydroxyl value of 150-250 are polymerized and foamed in the presence of a blowing agent (C), a catalyst (D), component E, etc.
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