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:
Feb. 15, 1994
Filed:
Apr. 24, 1992
Yutaka Muraki, Uji, JP;
Hidekazu Ishida, Nara, JP;
Hajime Kawai, Tsuzuki, JP;
Katsuhiko Tsunemitsu, Uji, JP;
Yamada Chemical Co., Ltd., Kyoto, JP;
Abstract
The present invention provides a novel phthalide compound represented by the following formula, which rapidly forms blue-blue black color with a developer when it is used as a recording material and, since a color image formed therewith has an intense absorption at 700.about.50 nm, it is usable for optical character reader; ##STR1## where R.sup.1 and R.sup.2 represent, independently, alkyl group having 6 or less carbon atoms; cycloalkyl group having 5 or 6 carbon atoms; aryl group; or heterocyclic ring connecting R.sup.1, R.sup.2 and N, R.sup.3 and R.sup.4 represent, independently, alkyl group having 6 or less carbon atoms; cycloalkyl group having 5 or 6 carbon atoms; aryl group; a heterocyclic ring connecting R.sup.3, R.sup.4 and N, X.sup.1 .about.X.sup.3 represent, independently, hydrogen atom, alkyl group having 6 or less carbon atoms, alkoxy group having 6 or less carbon atom or halogen atom, X.sup.4 represents hydrogen atom, alkyl group having 6 or less carbon atoms, alkoxy group having 6 or less carbon atom, halogen atom or ##STR2##