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. 21, 2009
Filed:
Sep. 14, 2004
Junji Momoda, Shunan, JP;
Yuichiro Kawabata, Shunan, JP;
Nobuyuki Tanaka, Shunan, JP;
Arihiro Iwata, Shunan, JP;
Junji Momoda, Shunan, JP;
Yuichiro Kawabata, Shunan, JP;
Nobuyuki Tanaka, Shunan, JP;
Arihiro Iwata, Shunan, JP;
Tokuyama Corporation, Yamaguchi, JP;
Abstract
A chromene compound of this invention, as shown in the following formula: characterized by having an indeno(2,1-f)naphtho(1,2-b)pyran structure as a basic structure, and having a substituent which is a substituted or unsubstituted aryl group such as methoxyphenyl group, or a substituted or unsubsterituted heteroaryl group such as thienyl group bonding to a carbon atom at the seventh position of the indeno(2,1-f)naphtho(1,2-b)pyran structure. The photochromic compound exhibits a color tone of a neutral tint when it develops a color, features a high color-developing sensitivity and a high fading rate, and has a good photochromic resistance.