METHOD OF PREPARING RIGID POLYURETHANE FOAM Russian patent published in 2000 - IPC

FIELD: chemistry of polymers. SUBSTANCE: described is method of preparing rigid polyurethane foam by reacting polyisocyanate with compound having at least two hydrogen atoms which are active with respect to isocyanate groups with molecular weight from 92 to 10,000, in the presence of water, dissolving agent and alkane as blowing agent. Dissolving agent is diethyl carbonate or tributyl phosphate, or product of reaction of tall oil fatty acid and 3-dimethylaminopropyl amine-1 at 2:1 molar ratio or methyltrioctyl ammonium chloride in amount of 15-20 parts per 100 weight parts of compound having at least two alkanes, e.g. cyclopentane in amount of 15-20 weight parts per 100 weight parts of compound having at least two hydrogen atoms which are active with respect to isocyanate groups. EFFECT: problem-free preparation of rigid polyurethane foams due to increased solubility of halide-free alkane blowing agent in polyol with retention of quality characteristics of polyurethane foams prepared by using halide-containing alkanes. 1 tbl