发明名称 Verfahren zur Gewinnung eines Gemisches von 2,4- und 2,6-Toluylendiisocyanat,das 65 bis 3 Gewichtsprozent des 2,4-Isomeren enthaelt
摘要 A process for the production of a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate containing 65/sB3% by weight of the former from a starting mixture of the two diisocyanates containing 70-90% by weight of a formula comprises freezing the starting mixture under substantially static conditions and bringing its temperature to 5-8 DEG C. so as to form a mixture of mother liquor and a coherent crystalline deposit rich in 2,4-toluene diisocyanate, and separating the mother liquor, while raising the temperature of the mixture by 0.5-3 DEG C., to produce a liquid fraction containing 65/sB3% by weight of 2,4-toluene-diisocyanate, and a crystalline residue containing 90-95% by weight of 2,4-toluene diisocyanate. In another feature of the invention a method of producing substantially pure 2,4-toluene diisocyanate from a starting mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate containing 90-95% by weight of the former prepared as above comprises freezing the starting mixture under substantially static conditions and bringing its temperature to 8-11 DEG C. so as to form a mixture of mother liquor and a coherent crystalline deposit, and separating the mother liquor while raising the temperature of the mixture to 18-21.5 DEG C. when the substantially pure 2,4-toluene disisocyanate is obtained as a crystalline residue.
申请公布号 DE1693220(A1) 申请公布日期 1970.07.23
申请号 DE19641693220 申请日期 1964.03.20
申请人 ALLIED CHEMICAL CORP. 发明人 CHUL PARK,JONG;BERNARD RECIA,EUGENE;THOMAS POLLEY,JAMES
分类号 B01D9/00;C07C265/12 主分类号 B01D9/00
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