| 摘要 |
<p>1520296 Decomposing polyurethanes DAIICHI KOGYO SEIYAKU CO Ltd 15 Sept 1975 [14 Sept 1974 11 Oct 1974 25 July 1975 12 Aug 1975 13 Aug 1975] 37777/75 Heading C3R Polyetherurethane resins are decomposed by heating at a temperature of 50‹ C. to 180‹ C. in the presence of (1) an alkali metal alcoholate obtained by alcoholating some or all of the OH groups of an alcohol or of an alkylene oxide adduct of an alcohol or amine with an alkali metal or alkali hydroxide, or (2) the alcoholate (1) and an alkali hydroxide, or (3) a combination of (1) or (2) with a decomposition accelerator selected from: (a) straight or branched chain aliphatic amines, alicyclic amines, heterocyclic amines and aromatic amines, (b) compounds prepared by cyanoethylating the amines (a) or by adding alkylene oxide to partially alkoxylate the amines (a) and (c) compounds containing amide or urea groups. The resins may be in the form of foams or elastomers. The decomposition products after separation and for addition polymerization with an alkylene oxide may be re-used in the preparation of polyurethanes.</p> |
