Color changing compositions
US5326388A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1993 |
| Grant date | Jul 5, 1994 |
| Priority date | — |
| Expiry date | Jul 16, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05D2451/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A multiple coloring composition system is disclosed whose coloring effect is changed upon treatment with a second coloring composition, once the second coloring composition has been deposited over the undercolor coloring composition. The multiple ink system comprises: PA1 (a) an undercolor aqueous coloring composition comprising an undercolor dye whose coloring ability is destroyed in the presence of a pH of about 10 or greater and/or by a reducing agent; and PA1 (b) an overcolor aqueous coloring composition comprising a colorant capable of maintaining its characteristic color in the presence of a pH of about 10 or greater and/or a reducing agent, a base in an amount sufficient to yield a pH of the overcolor composition of about 10 or greater, and/or a reducing agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.