| 摘要 |
PURPOSE:To obtain pictures having high contract and good stability by adding at least one of specific compounds as represented by specific general formulas to the covering layer of a thermal recording medium in which a color layer and a covering layer to make the color layer invisible are provided on a base material. CONSTITUTION:Since no wax is used for a covering layer, the reduction of sticking, etc., is not recognized. The covering layer is formed by using a regulated aqueous dispersion liquid of one or more of compounds (1)-(7) of the general formulas (where, although the formulas (1)-(3) only, except for (4)-(7), are described, R1, R2 and R3 in the formula are each H an alkyl and also R4 is a halogen or an alkyl, R1, R2, R3 and R4 in the formula (2) are each H, OH or alkoxy with or without substitution, but at least one of R2 and R3 is OH or alkoxy group, and R1 in the formula (3) is H, OH, an alkyl, allyl, alkoxy, aryl or aralkyl, and R2 is an alkyl, aryl or aralkyl group). The coating liquid is regulated by the addition of a water-soluble binder and a pigment, together with other additives as needed, and coated on a color layer formed on the base material by using a wire bar, etc. As the binder, polyvinyl alcohol, starch, isobutyene-maleic anhydride copolymer, hydroxyethyl cellulose, hydroxypropyl cellulose, etc., may be used. |
