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. 16, 1991
Filed:
Jun. 19, 1989
Ricoh Company, Ltd., Tokyo, JP;
Abstract
Leuco dyes of the formula (I) are disclosed, ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each represent an alkyl group having 1 to 10 carbon atoms; X represents hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms or a halogen; and Y represents R.sub.5 --Z--SO.sub.2 NH--, R.sub.6 --Z--CONH--, or ##STR2## in which Z represents ##STR3## R.sub.5 and R.sub.6 each represent hydrogen, an alkyl group having 1 to 10 carbon atoms, or a halogen; and R.sub.7 and R.sub.8 each represent hydrogen, provided that both R.sub.7 and R.sub.8 may not be hydrogen, a cyano group, or --COR.sub.9, in which R.sub.9 represents a lower alkyl group, a lower alkoxyl group, a phenyl group which may be substituted by an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, or a halogen; a naphthyl group which may be substituted by an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms or a halogen. Further a recording material comprising any of the above-mentioned leuco dyes and a particular phenolic compound as a color developer capable of inducing color formation in the leuco dye is disclosed.