| 摘要 |
PURPOSE:To obtain a thermal recording sheet having high water resistance and solvent resistance with favorable color forming property under ordinary manufacturing conditions without any heat treatment at high temperature, by incorporating a PVA resin, chitosan and an aldehyde resin into a thermal color forming component layer as a binder. CONSTITUTION:The polymerization degree of the PVA resin is selected in the range of 100-3,000, and the saponification degree thereof is selected in the range of 70-100mol%. As chitosan, one having an amino group content of not lower than 40% or one in which part or all of amino groups are converted into ammonium group by an acid is used. The molecular weight of chitosan is so selected that the viscosity (measured on a BL-type vicometer) of a 1% aqueous solution of chitosan at 20 deg.C is 1-70cp. Glyoxal or hexamethylenetetramine is used as the aldehyde compound from the viewpoints of easiness in use of a coating liquid and water-resisting effect. In mixing. 1-50 parts of chitosan and 1-20 parts of the aldehyde compound are preferably used per 100 parts of the PVA resin. |
