| 摘要 |
1340049 Polyureas IMPERIAL CHEMICAL INDUSTRIES Ltd 19 April 1971 [22 April 1970] 19288/70 Heading C3R [Also in Divisions C4 and D1] In Example 1 a polyurea is prepared by adding a 40% solution of polymerized mixed 2 : 4- and 2 : 6-tolylenediisocyanates containing 5À7% of isocyanate groups and less than 0À5% of free tolylene diisocyanate in acetone to a stirred solution of a fatty secondary amine derived from soya in acetone at 50-55‹ C. and then removing the acetone by distillation under reduced pressure. |
