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:
Dec. 28, 1982
Filed:
Feb. 17, 1981
Applicant:
Inventors:
Assignee:
Agfa-Gevaert Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03C / ; G07C / ; G09B / ;
U.S. Cl.
CPC ...
430542 ; 430223 ; 430242 ; 430440 ; 430483 ;
Abstract
5- or 6-membered .alpha.-lactones of phenolic compounds, in which the phenyl ring carries a hydroxyl or amino group in its 2- or 4-position to the lactonized phenolic hydroxyl group and in which the lactone ring carries an electron accepting substituent, so that the lactone ring is readily cleavable at pH values of from 10 to 13 to form an electron donor compound (ED-compound) having a redox potential of less than +0.255 V determined against a normal calomel electrode at pH 0 are useful ED precursor compounds for non-diffusing reducible color providing compounds.