Halogenated anthraquinone and their use as near infrared rays absorbing optical filters
US5342974A · kind A · utility
5Cited by
4References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1988 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Dec 28, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/244
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
High-purity 1,4,5,8-tetraanilidoanthraquinones which are substituted at the p-position of at least one of four anilido benzene rings by a halogen atom are good near infrared rays absorbing filters and at prepared from high purity 1,4,5,8-tetrachloroanthraquinone by reaction with a correspondingly substituted aniline or mixture of anilines in the presence of a salt of an aliphatic carboxylic acid,. a benzyl alcohol derivative and copper ions as reaction catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.