Thermochromic materials
US5294375A · kind A · utility
13Cited by
3References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1991 |
| Grant date | Mar 15, 1994 |
| Priority date | — |
| Expiry date | Aug 20, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B11/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Disclosed is a class of bridged phthalides and sulfinate esters which exhibit reversible thermochromism. At room temperature and in the presence of base, these compounds are substantially colorless but upon the application of heat they become colored, reverting to their original colorless or weakly colored state upon cooling. This colorless to colored, temperature-dependent cycle can be repeated many times. These compounds have utility as temperature sensors and as thermal pH indicators.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.