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:
Jan. 27, 1981
Filed:
Mar. 27, 1979
Applicant:
Inventors:
Assignee:
Toyo Soda Manufacturing Co., Ltd., Nanyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
546 49 ; 1062 / ;
Abstract
Finely divided gamma crystal phase quinacridone pigments are prepared by a process wherein a crude quinacridone of an arbitrary crystal phase is dissolved in dimethyl sulfoxide in the presence of a caustic alkali and water and then a mineral acid or a mixture of a mineral acid with at least one diluent selected from water, dimethyl sulfoxide and a monohydric alcohol having 1 to 3 carbon atoms is incorporated into the so-formed solution, thereby neutralizing the caustic alkali present in the solution to precipitate a finely divided gamma phase quinacridone.