| 摘要 |
PURPOSE:To enhance light resistance, productivity, optical characteristics or the like by using a chroconium coloring matter having a t-butyl-substd. nitrogen- containing heterocyclic ring at either end of its molecule as a recording material. CONSTITUTION:A recording layer comprises a chroconium coloring matter of formula I, wherein the heterocyclic ring at either end is a t-butyl-substd. nitrogen-containing heterocyclic ring, and each of R1 and R2 is a substd. or unsubstd. alkyl, cycloalkyl, allyl, substd. or unsubstd. aralkyl or substd. or unsubstd. aryl. The chroconium coloring matter, having a 5-membered ring at a central linking portion thereof, is structurally stable, and expansion of a delocalization region of pi-electrons causes a shift of absorption to the longer wavelength side, thereby enabling application of the coloring matter to a semiconductor laser with a wavelength of, for example, about 830nm. The solubility of the chroconium coloring matter depends heavily on substituent groups on the heterocyclic rings (nitrogen-containing heterocyclic rings) at both ends, and, particularly, introduction of t-butyl groups contributes effectively to enhancement of solubility of the coloring matter in general-purpose solvents. |
