Dye mixtures
US6635092B2 · kind B2 · utility
3Cited by
2References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2001 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Jul 11, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S8/919
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Disclosed are dye mixtures for shading white paper which may contain fluorescent brightener. The dye mixtures comprise a violet dye according to the formula (1) or (2) indicated in claim 1 and sufficient of a red, blue or further violet anionic azo dye that this dye mixture is capable of producing in the Cielab color co-ordinates system a relative hue angle of 270 to 295° when the dyeing contains 0.00005 to 0.005% by weight of dye, based on the weight of the paper, with the proviso that the value 0.005% is excluded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.