| 摘要 |
<p>Polyurethane foams of excellent properties are produced by reacting a) one or more polyether polyols, b) a polymethylene poly(phenyl isocyanate) having a methylene-bis(phenyl isocyanate) content of from 70 to 77% by weight, c) melamine, d) a phosphorous containing compound and d) water as the blowing agent. The isocyanate must have a specific 4,4' to 2,4'-isomer ratio and the amounts of melamine and phosphorous must be within narrowly defined limits.</p> |
