| 摘要 |
PURPOSE:To obtain an information-recording medium capable of recording and erasing information, by laminating, or incorporating in mixture, a light- absorbing material comprising a pyrylium compound of a specified formula. CONSTITUTION:A pyrylium compound of formula I, II, III or IV is laminated, or incorporated in mixture, as a light-absorbing coloring matter to produce an information-recording medium capable of recording and erasing information. In the formulas, each of X1 and X2 is sulfur, oxygen or selenium atom; Z1 is a hydrocarbon group comprising an atomic group necessary for completing pyrylium, thiopyrylium or the like which may be substd.; Z2 is a hydrocarbon group comprising an atomic group necessary for completing pyran, thiopyran, selenapyran, benzopyran or the like which may be substd.; each of R1, R2, R3 and R4 is hydrogen, a substd. or unsubstd. alkyl or substd. or unsubstd. aryl; each of R5, R6 and R7 is hydrogen, a halogen, substd. or unsubstd. alkyl, substd. or unsubstd. aryl or unsubstd. aralkyl; Z3 is an atomic group necessary for completing a substd. or unsubstd. nitrogen-containing heterocylic ring; and Z4 is a bivalent hydrocarbon group for forming a substd. or unsubstd. 5- or 6-membered ring. The information-recording medium is capable of displaying information by heating a specified region thereof to a specified temperature. |
