| 摘要 |
PURPOSE:To enhance the water resistance of a recording layer without bringing about the lowering of the whiteness thereof by adding specific SB type latex and polyvinyl alcohol to a thermal color forming layer as an adhesive. CONSTITUTION:In a thermal recording material provided with a thermal color forming layer containing a color former and a developer reacting with the color former at the time of heating to develop a color, SB type latex containing 25-40wt.% of a butadiene monomer and 60-80% of a gel and polyvinyl alcohol are added to the thermal color forming layer as an adhesive. When the copolymerizing ratio of butadiene is 25wt.% or less, film forming properties become inferior and, when said ratio is 40wt.% or more, cohesive force becomes weak and dry pick strength lowers. When the gel content is out of the above- mentioned range, water resistance and adhesive strength are lowered. The content of the styrene monomer constituting the SB type latex is pref. 40-70wt.% from the aspect of the stability of the latex and the wt. ratio of the SB type latex and polyvinyl alcohol is pref. 1:5 5:1 from the aspect of recording density, adhesive strength, water resistance, stickiness and the adhesion of refuse. |
