Thermally color-developing reversibly thermochromic pigment
US7332109B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2002 |
| Grant date | Feb 19, 2008 |
| Priority date | — |
| Expiry date | May 29, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M5/305
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A thermally color-developing reversibly thermochromic pigment which shows a uniform color density in the coloring temperature range and also shows an optimal ΔH value within a range of from 3 to 40° C. Thermally color-developing reversibly thermochromic pigments of a three component system having a ΔH value within a range of from 7 to 40° C. in which at least essential three components including (a) an electron-donating chromic organic compound, (b) a specified compound selected from the gallic acid esters and (c) a reaction medium selected from alcohols, esters, ketones and hydrocarbons; which reversibly generates color reactions of both of the compounds within a specified temperature range and has a melting point of less than 50° C., are microencapsulated, and of a four component system having a ΔH value within a range of from 3 to 25° C. in which a compound (d) selected from monomer compounds having a melting point of 50° C. or more or polymer compounds having a softening point of 70° C. or more is added to the three component system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.