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:
Dec. 12, 2000
Filed:
Sep. 18, 1998
Hans-Tobias Macholdt, Darmstadt-Eberstadt, DE;
Dieter Baumgart, Egelsbach, DE;
Rudiger Baur, Eppstein, DE;
Clariant GmbH, Frankfurt, DE;
Abstract
The use of an azo pigment of the formula (1) ##STR1## as a colorant in electrophotographic toners, electrophotographic developers, powders and powder coatings, and electret materials, wherein said azo pigment is prepared in the presence of 20 to 50% by weight of an auxiliary selected from the group consisting of a rosin, a salt of a rosin, an abietic acid, and a salt of an abietic acid, wherein said weight is based on the overall weight of the azo pigment including said auxiliary, and wherein the azo pigment has a specific surface area of more than 70 m.sup.2 /g and the azo pigment particles comprising the azo pigment have a length-to-width ratio of on average less than 2.8:1 and a mean particle size d.sub.50 of less than 130 nm.