The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 07, 1978
Filed:
Sep. 25, 1975
Applicant:
Inventors:
Joachim Ribka, Offenbach am Main, DE;
Wolfgang Rieper, Frankfurt am Main, DE;
Assignee:
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ; C09B / ;
U.S. Cl.
CPC ...
260208 ; 1062 / ; 1063 / ; 1063 / ; 106311 ; 260176 ; 260193 ;
Abstract
A process for the purification of azo pigments, wherein the crude pigment is stirred for some time in an aqueous alkaline suspension in a pH range from 9 to 12, preferably from 11 to 12, at temperatures between 20.degree. to 80.degree. C and subsequently the crude pigment is filtered off and washed neutral. The pigments treated by this process show a clearer and more brilliant shade and are faster to bleeding when incorporated, for example, into a thermoplastic material than the untreated pigments.