| 摘要 |
<p>1510231 Polyurethane foams TH GOLDSCHMIDT AG 29 Aug 1975 [30 Aug 1974] 35799/75 Heading C3R Polyurethane foams are prepared by reacting a polyether polyol, water and an organic polyisocyanate in the presence of a urethane-forming catalyst and 0À003 to 2% by weight, based on the weight of polyether of an organopolysiloxane or mixture of organopolysiloxanes of the general Formula I wherein if only one organopolysiloxane is used n=2 to 10, and, if a mixture of organopolysiloxanes I is used, the average value of n for the mixture is 2 to 10, the mixture containing not more than 0À5% of individual polysiloxanes in which n is 10 to 20 the mixture being substantially free from individual polysiloxanes where n is greater than 20, each R<1>, which may be the same or different, represents a hydrocarbon or substituted hydrocarbon radical which is free from groups which readily undergo reaction with isocyanate groups, R<2> is R<1> or OR<3> wherein R<3> is an alkyl, aryl, alkaryl or [CmH2mO]pR<4> radical wherein R<4> is a C1-5 alkyl radical, m is 2, 3 or 4 and p is chosen such that the molecular weight of the entire R<3> radical does not exceed 400.</p> |
