Stabilizer for electron doner-acceptor carbonless copying systems
US4372582A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1981 |
| Grant date | Feb 8, 1983 |
| Priority date | — |
| Expiry date | Mar 30, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24793
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.