| 摘要 |
PURPOSE:To provide a thermal recording material having excellent heat resistance and sensitivity by specifying property of nonfoamable plastic hollow finely divided particles contained in an underlayer and leuco dye and developer to be used for a thermal color developing layer. CONSTITUTION:Nonfoamable plastic hollow finely divided particles to be used for an under layer each contains thermoplastic substance as a shell, and liquid or gas therein and does not foam even if it is heated in such a manner that mean particle size is 2-10mum and degree of hollowness is 90% or more. The degree of the hollowness is the ratio of the outside diameter to the inside diameter of the hollow particle. The underlayer is formed of aqueous binder. Then, a thermal color developing layer containing compound expressed by formula I as leuco dye and compound expressed by formula II as developer is provided on the underlayer. In the formulae, R1, R2 are lower alkyl group, X is halogen. Thus, a thermal recording material having heat resistance and small fading is obtained. |
