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:
Jul. 06, 1999
Filed:
Dec. 03, 1997
Lindsay Kilmurray, deceased, late of Wilmington, DE (US);
Edward E Jaffe, Wilmington, DE (US);
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Abstract
A process for preparing transparent, pigmentary quinacridone compounds and solid solutions thereof comprises combining a premilled, sub-pigmentary powder containing at least one unsubstituted or substituted quinacridone or a derivative thereof with a sufficient amount of moderately concentrated sulfuric acid to form a slurry, then agitating this slurry in the presence of an organic liquid which is immiscible or only partially miscible with the slurry and which is effective in deagreggating and improving the crystallinity of the pigment, for an effective length of time to convert the sub-pigmentary unsubstituted or substituted quinacridone or solid solution thereof to a transparent, pigmentary form.