| 摘要 |
1,142,628. Polyisocyanates. MITSUBISHI CHEMICAL INDUSTRIES Ltd. 3 Aug., 1966, No. 34835/66. Heading C2C. Polyisocyanates are manufactured by introducing HC1 into a 5-18 wt. per cent solution of a polyprimary amine in an inert organic solvent at 40-150‹ C. until 30-95% of amine groups are converted to hydrochloride, and contacting the resulting slurry with phosgene. The preparation of tolylene (2,4- and 2,6-), 1,5 - naphthalene, 4,41 - diphenylmethane and hexamethylene diisocyanates is exemplified. |
