Opt. foamed isocyanurate gp. cong. polyurethane prepn. - by reacting poly:isocyanate(s) with crude polyether poly:ol(s) contg. alkali ions functioning as trimerisation catalyst

摘要

Opt. foamed, isocyanurate gp. contg. polyurethane are prepd. by reacting organic polyisocyanates and opt. additives and blowing agents with crude polyether polyols. The crude polyols contain alkali ions which act as a trimerisation catalyst and are cheaper than the alkali-free purified polyols. The polyols are also more reactive than alkali salts of organic carboxylic acids and alkali alcoholates. catalyst which must also be dissolved in monovalent alcohol solvent which acts as a chain stopper. The polyol shows no sedimentation after lengthy storage as with the above catalyst. The polyurethanes can be used as machine parts or when foamed as insulation mouldings can be removed from the mould after a short time.