| 摘要 |
Tolylene diiscyanate, prepared by phosgenating tolylenediamine in a solvent, is modified by reacting with either (1) 0.5-4 weight per cent of a polyol having 3-8 OH groups or (2) less than 7 weight per cent of a difunctional active-H containing substance (e.g. a diol), the mixture being then distilled to remove volatile matter until the distilland has a viscosity of at least 20 c.p.s. at 25 DEG C. and an amine equivalent of 90-130.ALSO:Cellular polyurethanes are prepared from tolylene diisocyanate (made by phosgenating tolylenediamine) which has been modified by reacting with either (1) 0.5-4 weight per cent of a polyol having 3-8 OH groups, or (2) less than 7 weight per cent of a difractional active -H containing substance (e.g. a diol), the mixture being then distilled to remove volatile matter until the distilland has a viscosity of at least 20 c.p.s. at 25 DEG C. and an amine equivalent of 90-130. In an example, such a modified diisocyanate is reacted at 20 degrees with a premix of a polyether triol, tetra-hydroxy-propyl) ethylene diamine, dibutyl Sn dilaurate and CFCl3. |
