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:
Apr. 02, 2002
Filed:
Jan. 28, 2000
Yuichi Yoshimura, Chiba-ken, JP;
Motoharu Takeuchi, Tokyo, JP;
Atsuki Niimi, Tokyo, JP;
Hiroshi Horikoshi, Chiba-ken, JP;
Masaaki Takasuka, Chiba-ken, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A process for tinting a resin for optical materials, the resin containing sulfur, includes dipping the resin for optical materials into a liquid containing an inorganic acid and/or an organic acid and thereafter tinting the resin. Where the organic acid is included in the liquid, the organic acid is a mixture of a first compound (I) having sulfo group and a second compound (II) having phenolic hydroxyl group but not having sulfo group, with a ratio (I)/(II) of the first compound to the second compound, in an amount by weight, being 0.01 to 2.0.