Cholesteric liquid crystal of the reentrant type and a temperature-detecting device entailing the use of a liquid crystal of this type
US4410283A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1981 |
| Grant date | Oct 18, 1983 |
| Priority date | — |
| Expiry date | Aug 26, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K19/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Cholesteric liquid crystals of the so-called reentrant mesogenic type obtained by mixing a substance such as a cholesterol ester having molecules of the "chiral" type with a liquid crystal of the so-called reentrant nematic type such as a substance corresponding to the general formula: ##STR1## where R is an alkyl or alkoxy or alkylcarbonate group with: EQU R'=H or CH.sub.3 and X is an organic radical such that CH=N, CH=CH, C.tbd.C or COO. The use of a liquid crystal in accordance with the invention serves to obtain a temperature-detecting device in which, in contrast to conventional cholesteric devices, the reflected light changes from blue to red when the temperature rises.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.