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. 30, 1998
Filed:
Apr. 25, 1997
Nobuyuki Tomiya, Tokyo, JP;
Mikio Hayashi, Tokyo, JP;
Toyo Ink Manufacturing Co., Ltd., Tokyo, JP;
Abstract
The present invention is a method for preparing a .beta.-form copper phthalocyanine pigment comprising the steps of; dry milling crude copper phthalocyanine at a temperature between 110.degree. and 200.degree. C., and transforming an .alpha.-form crystal to a .beta.-form crystal by treating the resulting .alpha.-.beta. mixture of copper phthalocyanine in an organic solvent or a liquid mixture of water and an organic solvent. The preparation method of the present invention offers a .beta.-form copper phthalocyanine pigment at lower cost having equivalent or superior quality in color strength, clearness, fluidity and hue compared to the pigment produced by the conventional salt milling method.