CAS: 22094-93-5; Pigment Yellow 81

专利信息

专利号:US-5243032-A
优先权日:1989-06-22
标题:Preparation of azo pigments with low pcb content by coupling in the presence of olefins
发明人：RIEPER WOLFGANG
权利人:HOECHST AG
摘要:The production which is customary in practice of monoazo compounds based on dichloro- and trichloroanilines or disazo compounds of the chlorinated biphenyl series by conventional coupling methods meets with difficulties in that the resulting pigments are contaminated by traces of polychlorinated biphenyls. n According to the invention, it has now been found that by addition of water-soluble olefins of the type ##STR1## (R =H, alk or Oalk; X =--COOR 1 , --CONHR 2 or --NR 3 COR 4 ) n in the azo coupling, the side reactions which form PCBs can be decidedly suppressed during synthesis of the pigments.

专利号:US-5194597-A
优先权日:1990-05-02
标题 :Preparation of a coupling product of bisiazotized 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl with two equivalents of n-acetoacetyl-2,4-dimethylanilide
发明人：RIEPER WOLFGANG
权利人:HOECHST AG
摘要:The industrial preparation of C.I. Pigment Yellow 81 by conventional coupling methods has the disadvantage that traces of polychlorinated biphenyls are formed in the course of the reaction of the two components. n The invention now provides that the addition of quaternary dialkyldiallylammonium compounds during the azo coupling will decisively suppress the PCB-forming secondary reactions during the pigment synthesis.

专利号:CN-115650860-B
优先权日:2022-10-31
标题 :Synthesis method of 2,2',5,5'-tetrachlorobenzidine