Silicone-containing polyurethane foam

摘要

Low density silicone-containing polyurethane foams with excellent surface characteristics are prepared by reacting a foamable composition containing a siloxane of the formula;
and an isocyanate, in the presence of at least one blowing agent.

主权项

1. A foamable composition, comprising
(A) at least one siloxane of the formulawhere
R in each occurrence is the same or different and is hydrogen or a monovalent, optionally substituted hydrocarbon radical, R1 in each occurrence is the same or different and is a divalent, optionally substituted hydrocarbon radical optionally interrupted by heteroatoms, R2 in each occurrence is the same or different and is a divalent, optionally substituted hydrocarbon radical optionally interrupted by heteroatoms, R3 in each occurrence is the same or different and is hydrogen or a monovalent, optionally substituted hydrocarbon radical, X in each occurrence is the same or different and is —O—, —S— or —NR4—, R4 is hydrogen or a monovalent, optionally substituted hydrocarbon radical, n is the same or different and is an integer not less than 1, and m is an integer not less than 1, with the proviso that at least one R3 radical in formula (I) is an optionally substituted hydrocarbon radical having at least one hydroxyl group and/or thiol group, and (B) a polyisocyanate.