| 摘要 |
Novel, liquid polyisocyanate mixtures containing urethane groups and having an NCO content of from 15 to 30 % by weight are obtained by reacting… a1) polyisocyanates or polyisocyanate mixtures from the diphenylmethane series with… b) substoichiometric amounts of at least one polyether-polyol having a (mean) hydroxyl equivalent weight of from 500 to 3000 and a (mean) hydroxyl functionality of greater than 4,… and, if desired, subsequently blending the reaction product with… a2) urethane group-free polyisocyanates or polyisocyanate mixtures from the diphenylmethane series, the diisocyanatodiphenylmethane isomer content in components a1) and a2) totalling from 50 to 95 % by weight,… and are used in the production of soft polyurethane foams. |
