| 摘要 |
1,144,250. Curable polyurethane compositions. WYANDOTTE CHEMICALS CORP. 7 Aug., 1967 [15 Aug., 1966], No. 36198/67. Heading C3R. [Also in Division B2] Curable polyurethane compositions comprise (1) a prepolymer having terminal hydroxyl groups and which is the reaction product of (a) a polyoxyalkylene polyol with (b) an organic polyisocyanate, (2) an alkoxyalkylamino compound and (3) an acid catalyst. The polyurethane prepolymers may be prepared in a conventional manner from polyethers containing 2 to 8 hydroxyl groups in an OH: NCO ratio of 8: 1 to 1000: 999. Suitable alkoxyalkylamino compounds are alkoxyalkyl substituted guanamines, thioureas, acrylamides, benzene sulphonamides and toluene sulphonamides, alkylated urea - formaldehyde and alkylated melamine-formaldehyde compounds either in the monomeric or polymeric form. In general, there should be 0À5 to 5 alkoxyalkylamino compound equivalents for each hydroxyl group of the prepolymer. The acid catalyst (3) is preferably p-toluenesulphonic acid and may also be xylene sulphonic acids, o- and m-toluene sulphonic acids, ethyl acid phosphate, n-butyl phosphoric acid, inorganic acids, ammonium chloride or sulphate, acetyl-, propionyl, benzoyl and adipyl chlorides and organic acids. The amount of catalyst is suitably 0À001 to 5À0% of the combined weight of prepolymer and alkoxyalkylamino compound. The composition may also contain a solvent, so as to give a composition containing 5 to 90% weight per cent solids. The compositions are cured by heating at 150‹ to 500‹ F. |
