Indolylazaphthalides and recording materials containing the same
US5691271A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1996 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | May 16, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M5/327
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The present invention provides novel indolylazaphthalides represented by formula (I) described below. The indolylazaphthalides are useful as electron donative colorless dyes for preparing recording materials. Recording materials containing the novel indolylazaphthalides of formula (I) as electron donative colorless dyes provide images having blue to cyan colors at an excellent density, while suppressing light coloration in non-image areas. ##STR1## wherein R.sup.1 represents a divalent linkage group such as an alkylene group, cycloalkylene group, aralkylene group, or a phenylene group, which linkage group is linked to a bimolecular indolylazaphthalide compound to form a bis-type structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.