Color changing compositions
US5232494A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1992 |
| Grant date | Aug 3, 1993 |
| Priority date | — |
| Expiry date | Jul 31, 2012 |
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 first coloring composition. The multiple ink system comprises: PA0 (a) a first aqueous coloring composition comprising a first dye whose coloring ability is destroyed in the presence of a bleach; and PA0 (b) a second aqueous coloring composition comprising from about 1% to about 20% by weight of a bleach; and from about 0.1% to about 12% by weight of a colorant capable of maintaining its characteristic color in the presence of a bleach and/or a pH of about 10 or greater. PA0 The multiple coloring composition may further comprise a base in an amount sufficient to elevate the pH of the second aqueous coloring composition to a level of from about 10 to about 12.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.