| 摘要 |
An improved process for the copolymerization of a mixture of a bicyclic amide acetal and a polyisocyanate comprising carrying out the copolymerization reaction at a temperature in the range of from about ambient temperature up to about 200.degree.C. in the presence of a catalytic amount of a salt of a metal selected from the group consisting of bismuth, lead, mercury, copper, vanadium, cobalt, nickel, potassium, zinc and antimony is described. |
