Verfahren zur Herstellung von Polyesterschaumstoffen

摘要

1,216,158. Polyester-based foams. TH. GOLDSCHMIDT A.G. 16 June, 1969 [4 July, 1968], No. 30443/69. Headings C3C, C3R and C3T. Polyester urethane foams or foams prepared from hardenable unsaturated polyesters are prepared in the presence of a foam stabilizer which is a polyoxyalkylene-polysiloxane mixed block polymer wherein (a) the polyoxyalkylene blocks have an average M.W. of 1400 to 3000 and consist of 65 to 100% by weight of ethylene oxide and (b) the polysiloxane blocks contain an average of 3 to 15 silicon atoms of which 2 to 12 are present as dimethylsiloxy radicals while the remaining Si atoms form trifunctional siloxy units and/or are connected to the polyoxyalkylene block. The polyoxyalkylenepolysiloxane block polymers exemplified are those of the formula wherein X is [-C n H 2n O] n Z, m and n are integers, Z is an alkyl, aryl or acyl radical, M is -O-; -CH 2 O-; -(CH 2 ) 3 O-; R1 and R2 are each an alkyl radical containing 1 to 4 carbon atoms or MX, R3 is the same as R1 or R4 is a divalent hydrocarbon radical, a = 0 to 10; b = 0 to 3; c = 1 to 10; d = 0 to 3 and c + d = 1 to 13 with the proviso that the values of m, n, a, b, c and d provide a polymer as defined above.