| 摘要 |
PURPOSE:To enhance heat resistance and thermal response by providing an intermediate layer based on non-foamable plastic fine hollow particles having a predetermined average particle size and a specific degree of hollowness between a support and a thermal color forming layer and setting the static color forming start temp. of the color forming layer to a specific temp. CONSTITUTION:An intermediate layer is formed between a thermal color forming layer utilizing the color forming reaction of a leuco dye, for example, 3,3-bis(p-dimethylaminophenyl)-phthalide and a developer, for example, 4,4'- isopropylidene diphenol and a support using a water-soluble polymer based on fine hollow particles each formed by including air or other gas in a shell with an average particle size of 2-20mum and the degree of hollowness of 80% or more composed of non-foamable plastic, for example, a thermoplastic resin such as polystyrene. The coating amount of fine hollow particles at this time is set to 1g or more per 1m<2> of the support. The static color forming start temp. of the thermal color forming layer is set to 120-150 deg.C. |
