Title:
【発明の名称】アゾ顔料の製造法
Document Type and Number:
Japanese Patent JPH0784566
Kind Code:
B2
Abstract:
In a process for preparing azo pigments by the azo coupling reaction of a diazo component with the equivalent amount of a coupling component which is sparingly soluble under acid and neutral pH conditions below 65 DEG C, an alkaline solution of the coupling component is continuously mixed in a first reaction step with an aqueous solution of an acid selected from the group consisting of acetic acid, boric acid, phosphoric acid, hydrochloric acid and sulphuric acid at below 65 DEG C for less than 1 minute, during which the coupling component precipitates at least partially in reactive form, and the resulting suspension is continuously mixed in an immediately subsequent second reaction step with an acid solution of the diazo component at below 65 DEG C for less than 1 minute, and the mass flows of the diazo component and the coupling component are control-set to a certain pH between 2 and 9, as a result of which a portion of the coupling component is immediately converted into the desired azo pigment while the remainder is not converted into the desired azo pigment with still unconverted diazo component until a post reaction phase.
Inventors:
Heinrich Labelberg
Hartmut Boehringer
Hartmut Boehringer
Application Number:
JP10906987A
Publication Date:
September 13, 1995
Filing Date:
May 06, 1987
Export Citation:
Assignee:
Hoechst Actien Gezershaft
International Classes:
C09B41/00; (IPC1-7): C09B41/00
Attorney, Agent or Firm:
Toshio Yano (1 outside)
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