| 摘要 |
Hot-curing soft polyurethane moulded foams are prepared by reacting… a) polyisocyanates of the diphenylmethane diisocyanate and/or tolylene diisocyanate and/or hexamethylene diisocyanate and/or isophorone diisocyanate type with… b) compounds which contain at least two hydrogen atoms which are active towards isocyanates and have a molecular weight of 400 to 10,000 and, if desired,… c) chain extenders and crosslinking agents containing at least two hydrogen atoms which are active towards isocyanates and have a molecular weight of 32-399, in the presence of… d) carbonic acid diamide as catalyst in an amount of from 0.05 to 1.0 parts by weight, based on 100 parts by weight of component b) and… e) water as blowing agent in an amount of from 5 to 15 parts by weight, based on 100 parts by weight of component b), and, if desired, in the presence of… f) other blowing agents, catalysts and further assistants and additives which are known per se, in a closed mould, the reaction of all the components being carried out at a characteristic number of less than 90, preferably 75-85. |
