METHOD OF OBTAINING ELASTIC, FOAMED BLOCK POLURETHANE POLYMER MATERIALS

摘要

A method for the preparation of elastic block soft foam materials comprises reacting the following components together :(A) polyisocyanates ; (B) polyol compounds with a molecular weight of 400-10000 containing at least two hydrogen atoms that can react with (A) ; (C) water and optional organic propellants ; (D) standard stabilisers ; (E) standard activators ; and (F) other standard auxiliary agents and additives. (B) comprise : (B1) compounds with a molecular weight of 2000-10000, functionality of 2-4 and containing at least two hydrogen atoms that can react with (A) ; (B2) compounds with a molecular weight of 400-4000 (500-3000), functionality of 4-8 (4-6) and containing at least four hydrogen atoms that can react with (A) ; and (B3) optional cross-linking agents with a molecular weight of 32-399. Liquid carbon dioxide (G) is used as an extra propellant in the preparation of the foam and depressurised in a decompression chamber containing a fine mesh before the foam is dispensed.