| 摘要 |
A process for the production of non-cellular polyurethanes comprises reacting an organic polyisocyanate with at least one polyhydroxyl compound having a MW of at least 500, and, simultaneously or subsequently, with a cross-linking agent having a M.W. of up to 400, wherein the polyisocyanate is used in an excess of from 1147% up to 4000% calculated on the hydroxyl groups of the polyhydroxyl compound. The polyhydroxyl compound may be a linear saturated or unsaturated polyester, polyesteramide, polyether, polythioether or polyacetal of M.W. from 1000-3000. The unsaturated polyester may be copolymerized with a vinyl compound e.g. styrene acrylonitrile, acrylic and methacrylic ester, in the presence of an accelerator e.g. dibenzoyl peroxide, azodiisobutyronitrile or cumene-tertiary butyl peroxide. The polyisocyanate may be aliphatic, cycloaliphatic or aromatic. In Example (1) an adipic acid ethylene glycol polyester was reacted with tolylene diisocyanate and butane 1 : 4 diol the diisocyanate being present in an excess of 1336%. In Example (6) an ethylene glycol adipic acid polyester was mixed with a polyester derived from perhydrogenated di-(b -hydroxy ethoxy) diphenyl dimethyl methane and maleic acid, styrene, trimethylol propane and reacted with tolylene diisocyanate to provide an excess of 1666%. |
