| 摘要 |
PURPOSE:To increase thermal response and to improve the uniformity of a colored image, by using p-hydroxybenzoic acid ester as a color developing substance forming a thermosensitive color-forming layer. CONSTITUTION:A p-hydroxybenzoic acid ester compound given by the formula (where R is a 2-4C alkyl or benzyl radical) for instance, ethyl p-hydroxybenzoate or n-propyl p-hydroxybenzoate is compounded as a color-developing substance in a thermosensitive color-foriming layer. As a color-forming substance, a triphenylmethane compound is used, while a water-soluble polymer is used as a binder. The p-hydroxybenzoic acid ester has a melting point of 60-120 deg.C and higher color-developable, so that if offers high thermal response, that is, high color density in recording as compared with the color-developing agent of the prior art. Thus a uniform, clear colored image can be obtained. |
