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:
Jun. 05, 2001
Filed:
Jul. 12, 1999
Applicant:
Inventors:
Manfred Urban, Wiesbaden, DE;
Martin Boehmer, Neu-Anspach, DE;
Dieter Schnaitmann, Eppstein, DE;
Joachim Weber, Frankfurt, DE;
Assignee:
Clariant GmbH, Frankfurt, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B 4/800 ; C09B 6/752 ; C09B 6/722 ; C09B 6/710 ;
U.S. Cl.
CPC ...
C09B 4/800 ; C09B 6/752 ; C09B 6/722 ; C09B 6/710 ;
Abstract
Linear unsubstituted and substituted quinacridone pigments and quinacridone mixed-crystal pigments are obtained by cyclizing dianilinoterephthalic acid with polyphosphoric acid and then hydrolyzing the ring closure mixture, said mixture being metered into an amount of water or orthophosphoric acid which is such that the final orthophosphoric acid concentration is greater than or equal to 50% by weight in the hedrolysis mixture.