| 摘要 |
1529821 Polyurethane-modified polyisocyanurate foams M & T CHEMICALS Inc 17 Sept 1975 [9 April 1975] 38258/75 Heading C3R A process for the preparation of a polyurethane modified polyisocyanurate foam comprises reacting an organic polyol contianing at least two reactive hydrogen atoms with an organic polyisocyanate simultaneously to trimerize the polyisocyanate and to form urethane groups, the reaction being carried out in the presence of 0À01 to 5 parts by weight of a 1,3,5-tris(N,N-dialkylamino alkyl) hexahydrotriazine, or an adduct thereof with an alkylene oxide and water, and 0À01 to 5 parts by weight of an alkali metal salt of a carboxylic acid containing from 2 to 19 carbon atoms per 100 parts by weight of the organic polyisocyanate. The preferred alkali metal salt is potassium-2- ethyl hexoate and the preferred triazine is 1,3,5-tris-(dimethylaminopropyl)-hexahydrotriazine. The preferred polyisocyanate is polymethylene polyphenylene polyisocyanate and suitable polyols are castor oil, OH-containing polyesters, polyalkylene polyethers, polyurethanes and polythioethers, and monomeric, oligomeric or polymeric aliphatic glycols. Optional additives include surfactants, fillers, pigments and blowing agents. |
