Leuco dyes and recording materials using the same
US5024699A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1990 |
| Grant date | Jun 18, 1991 |
| Priority date | — |
| Expiry date | Mar 2, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/913
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A leuco dye having the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represent a lower alkyl group; R.sup.5 represents an .alpha.-naphthyl group, .beta.-naphthyl group or ##STR2## wherein R.sup.6 represents --NHCOR.sup.9, a halogen or an amino group which is unsubstituted or substituted by one or two C.sub.1 -C.sub.4 alkyl groups which are the same or different; and R.sup.7, R.sup.8 and R.sup.9 each represent hydrogen or a lower alkyl group, provided that when both R.sup.7 and R.sup.8 are hydrogen, R.sup.6 represents --NHCOR.sup.9 or bromine. These dyes absorb in the near-infrared region and yield colored images with a color developer therefor with excellent preservability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.