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. 22, 1994
Filed:
May. 10, 1993
Applicant:
Inventors:
Gunther Beck, Leverkusen, DE;
Bernd Kaletta, Langenfeld, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
540122 ;
Abstract
Metal-free phthalocyanines in the .chi.-modification substituted in up to four ortho positions can be prepared by tetramerisation of a reaction mixture consisting of phthalonitriles substituted in the 3-position with phthalonitrile in a molar ratio of 4:0 to 1:40 in the presence of a base and subsequent heat treatment at temperatures of between 100.degree. and 300.degree. C. They constitute excellent organic pigments.