| 摘要 |
1387318 Tolylene diisocyanate E I DU PONT DE NEMOURS & CO 26 April 1972 [26 April 1971] 19393/72 Heading C2C [Also in Division C3] The invention comprises a process for the preparation of undistilled tolylene diisocyanate in which tolylene diamine is substantially completely phosgenated and thereafter the acidity of the product is adjusted to form 0�03 to 0�3 weight percent. The adjustment of acidity may be made by either maintaining the undistilled phosgenation product in a phosgenation atmosphere at a temperature of 100-200� C. for at least 0�08 hour or by adding 0�003 to 0�05 equivalents of an acid halide per 100 g of phosgenated diamine. Specified acid chlorides are HCl, HBr, HI, COCl 2 , CH 3 COCl, C 6 H 5 COCl, COBr 2 , phthaloyl chlorides, succinoyl chloride, trimesoyl chloride and adipoyl bromide. |
