Loading patent…
AssigneeFuji Photo Film Co., Ltd.
InventorsNaoto Yanagihara, Kiyoshi Takeuchi, Toyohisa Oya, Naoki Asanuma, Masanobu Takashima, Syunsaku Higashi
Estimating the term…
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.
A recording material formed of a substrate having thereon an electron donative colorless dye and an electron accepting compound, comprising at least one indolylazaphthalide represented by the following formula (I) as the electron donative colorless dye:
A multi-color heat-sensitive recording material comprising a support having thereon two heat-sensitive layers in which two diazonium salt compounds having different sensitization wavelengths are combined with couplers which develop different hues after reaction in the presence of heat, an electron donative colorless dye, and an electron accepting compound, wherein the electron donative colorless dye comprises indolylazaphthalide represented by the following formula (I):
Dependencies are inferred from the claim text.