| 摘要 |
PURPOSE:To obtain a high-sensitivity optical information recording medium excellent in stability to reproducing light and thermal stability, by providing an organic thin film comprising a specified compound, on a substrate. CONSTITUTION:A compound of formula (I), wherein each of R<1> and R<2> is hydrogen or a lower alkyl, Ar is a substd. or unsubstd. aromatic heterocyclic ring, and X is an anion, is useful as a stable optical information recording medium, the stability being further enhanced when the compound is used in combination with other organic coloring matter recording material (particularly, a cyanine coloring matter or a merocyanine coloring matter). An organic thin film recording layer 2 comprising the compound of formula (I) as a main constituent is provided on a substrate 1. An undercoat layer 3 may be provided between the substrate 1 and the recording layer 2, or a protective layer 4 may be provided on the recording layer 2. The amount of the compound of formula (I) added, on a total solid component basis, is suitably 2-60 wt.% based on the recording layer, and is suitably 2-90 wt.% based on the undercoat layer 3 or the protective layer 4. |
