| 摘要 |
A fire retardant polyurethane has 3-bromo-2,2 - bis(bromoethyl) - propanol, 2,2 - bis-(bromoethyl) -1,3-propandiol or a mixture thereof incorporated therein. The polyurethane may be prepared by reacting (1) a polyether polyol of equivalent weight 600-1200 with (2) an organic polyisocyanate and (3) the brominated alcohol in such amount that the final product contains 6-20% Br and (4) additional polyhydric alcohol in amount to maintain the -NCO/OH ratio of 1.0 to 1.8. The polyurethane may contain a flow control agent, e.g. cellulose acetate butyrate, an antioxidant, e.g. 2,6-di-tert.-butyl-4-methyl phenol and an aromatic solvent, e.g. benzene.ALSO:A fire resistant polyurethane obtained by reaction of polypropylene glycol with tolylene diisocyanate and 2,2 bis (bromoethyl)-1,3 propanediol in the presence of an antioxidant, solvent and flow control agent is painted on to the untreated side of fibre board panels and allowed to cure in moist air. |
