Color changing pan paint compositions
US5498282A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1994 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Oct 3, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05D2451/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Pan paints and associated color-changing systems are disclosed. In a first embodiment, the color-changing system comprises an undercolor pan paint coloring composition comprising an undercolor dye whose coloring ability is destroyed in the presence of a pH of about 10 or greater and/or in the presence of a reducing agent; and an overcolor composition comprising a colorant capable of maintaining its characteristic color in the presence of a pH of about 10 or greater and/or in the presence of a reducing agent, and a base such that the pH of the overcolor composition is about 10 or greater and/or a reducing agent. In a second embodiment, the color-changing system comprises an undercolor coloring composition comprising an undercolor dye whose coloring ability is destroyed in the presence of a pH of about 4 or less; and an overcolor coloring composition comprising a colorant capable of maintaining its characteristic color in the presence of a pH of about 4 or less and an acid such that the pH of the overcolor coloring composition is about 4 or less; wherein one or both of the coloring compositions is a pan paint.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.