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. 08, 1983
Filed:
Mar. 30, 1981
Thomas C Geisler, Cottage Grove, MN (US);
Minnesota Mining and Manufacturing Company, Saint Paul, MN (US);
Abstract
A stabilizing agent for use in electron donor-acceptor carbonless copying systems. The stabilizing agent is 2,2'-methylene-bis(4-methyl-6-t-butyl phenol). Systems in which the stabilizing agent is useful comprise a color-forming composition comprising at least one leuco dye which is fadeable or discolorable after development, a color-developing composition comprising an acidic coreactant material capable of reacting with the color-forming composition to provide colored products, and the stabilizing agent. The stabilizing agent prevents discoloration or fade of images produced by reaction of the color-forming composition with the color-developing composition. In a preferred embodiment, the color-forming composition additionally comprises dithiooxamide and/or dithiooxamide derivatives, the color-developing composition additionally comprises a transition metal ion capable of reacting with the dithiooxamide compound to produce a purple-colored product, and the reaction of the color-forming composition with the color-developing composition results in a neutral black colored product.