| 摘要 |
PURPOSE:To attain to enhance storage stability, especially, water resistance, oil resistance, plasticizer resistance and chemical resistance, by constituting the binder of a thermal color forming layer and the main component resin of an intermediate layer of a hot water soluble sulfonate group-containing polyester resin and forming a protective layer from a ultraviolet curable resin. CONSTITUTION:A sulfonate group-containing polyester resin is prepared by an arbitrary method. For example, a method for condensing dicarboxylic acid, alkylene glycol and sulfonate group-containing dicarboxylic acid is most general. As polyester, one with a hydroxyl value of 2-20KOHmg/g, pref., 4-10KOHmg/g is desirable. The content of a sulfonate group is properly 3-30mol%. The fundamental composition of the ultraviolet curable resin for a protective layer consists of an oligomer, a crosslinking agent and a photoinitiator. As the oligomer, polyester acrylate or urethane acrylate are pref. because has good adhesiveness with a thermal layer or an intermediate layer. In addition, silicone oil or silicone resin improving the matching property with a thermal head may be added. |
