| 摘要 |
1345117 Crystallizing diamine dicarboxylates ASAHI KASEI KOGYO KK 5 May 1972 [8 May 1971] 21076/72 Heading C2C A crystalline diamine dicarboxylate derived from a diamine R<SP>1</SP>(NH 2 ) 2 , where R<SP>1</SP> is pheny. lene, cyclohexylene or C 4-12 alkylene, and a dicarboxylic acid R(COOH) 2 , where R is phenylene, cyclohexylene or C 2-8 alkylene, is precipitated from an aqueous liquid containing the salt and the acid by adding a sufficient amount of the diamine to maintain the pH of the aqueous liquid at 5-10, at a temperature of 20-100‹ C. The liquid may also contain the salt and acid in suspension, the suspended acid dissolving to form salt. |
