| 摘要 |
PURPOSE:To obtain a thermal recording layer having excellent water resistance and chemical resistance, by using a photosensitive polyvinyl alcohol having a structural unit of a specified general formula, as a binder. CONSTITUTION:A thermal recording layer provided, on a base, with a thermal recording layer comprising a color forming substance, a color developer and a binder as main constituents is produced as follows. For example, the color forming substance and the color developer are separately dispersed in a particle size of not more than several micrometers by a ball mill or the like while using a binder, the two dispersed liquids thus obtained are mixed with each other, and an adhesive, a filler, a surfactant or the like is appropriately added to the resultant mixture to obtain a coating liquid for forming a thermal color forming layer. The coating liquid is applied to a sheet form base such as a paper or a plastic sheet. A photosensitive polyvinyl alcohol having a structural unit of general formula I, wherein R<1> is a quaternary aromatic nitrogen- containing heterocyclic ring residue, R<2> is hydrogen or a lower alkoxyl, m is 0 or 1, n is an integer of 1-6, is used as the binder. The applied material is irradiated with UV rays without heating, thereby providing the thermal recording layer with excellent water resistance and chemical resistance. |
