| 摘要 |
PURPOSE:To provide excellent water resistance and chemical resistance and lower the possibility of adhesion of scum to a thermal head at the time of recording, by using a photosensitive polyvinyl alcohol having a structural unit of a specified general formula, as a film forming high molecular weight compound in an overcoat layer. CONSTITUTION:A thermal recording material is produced as follows. For example, a color forming substance and a 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 and a plastic sheet, and is dried at a relatively low temperature to provide a thermal recording layer. A film forming high molecular weight compound comprising 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 2, and n is an integer of 1-6, is applied to the thermal recording layer, and after drying, it is irradiated with UV rays by using a high pressure mercury lamp or the like to provide an overcoat layer, thereby obtaining the thermal recording material. |
