Thermally sensitive recording medium
AssigneeNopon Paper Industries Co Ltd
InventorsYoshimi Midorikawa, Kaoru Hamada, Yoshihide Kimura, Tomoaki Nagai
Life of this patent
Estimating the term…
Abstract
The thermally sensitive recording medium having sufficient color developing density and develops navy blue or grayish blue color. The color difference L* value a* value and b* value of developed image of said thermally sensitive recording medium regulated by JIS-Z-8729 are within the regions of, A. L* value is 30˜50, a* value is −15˜0 and b* value is −30˜10, B. L* value is 30˜50, a* value is 0˜10 and b* value is −30˜0 or C. L* value is 30˜50, a* value is 10˜20 and b* value is −30˜15.
Claims10
A thermally sensitive recording medium, comprising a substrate and a thermally sensitive color developing layer developing a navy blue or grayish blue color carried on said substrate, said layer comprising a colorless or pale colored dye precursor and a color developer, wherein the dye precursor comprises
- (a) at least one bluish color developing leuco dye selected from the group consisting of 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-dimethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, and mixture thereof, and
- (b) at least one black color developing leuco dye having maximum absorption wavelengths of from 420 to 480 nm and from 550 to 640 nm.
Dependencies are inferred from the claim text.