| 摘要 |
PURPOSE:To improve transparency and layer adhesive by providing a support, a heat sensitive coloring layer made of leuco dye and developer, and an intermediate layer containing aqueous acryl emulsion as main ingredient and modified polyvinyl alcohol. CONSTITUTION:Leuco dye is used solely or in mixture of two or more types, and includes, for example, leuco compound of dye such as triphenylmethane, fluoran, etc. As developer, electron acceptive compound for coloring at the time of contact with the leuco dye such as phenol compound, thiophenol compound is employed. Aqueous acryl emulsion includes, for example, styrene/acrylic copolymer, vinyl acetate/acrylic copolymer, and modified polyvinyl alcohol, and its mixing ratio is aqueous acryl emulsion rich and 1:1 as its limit. Thus, its transparency is high, a layer adhesive is improved, and the total sum of a coloring component and filler of a heat sensitive coloring layer is 80wt.% or less, thereby enhancing the transparency. |
