Reversible temperature-indicating composition
US4732810A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1985 |
| Grant date | Mar 22, 1988 |
| Priority date | — |
| Expiry date | Dec 23, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2984
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A new reversible temperature indicating composition for use in temperature indicating instruments is diclosed which is capable of accurate temperature indication in a variety of colors and characterized by a minimum range of hysteresis so that the marking drawn in this composition can decolor at or close the temperature at which its coloring takes place. In addition, the composition can provide a wide variety of hues and can be readily prepared. These and other advantages are provided by the inclusion as a main ingredient of an ester compound having .DELTA.T value, defined .DELTA.T=melting point--clouding point, in the range under 3.degree. C., the value that determines a desirably small range of hysteresis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.