SALICYLIC ACID DERIVATIVE ZINC SALT HYDRATE AND HEAT-SENSITIVE RECORDING MATERIAL CONTAINING THE SAME

摘要

PURPOSE:To obtain the subject hydrate useful as an electron accepting compound for heat-sensitive recording materials. CONSTITUTION:Hydrate of zinc salt of a salicylic acid derivative of the formula (R is H, a 1-4C alkyl or a 1-4C alkoxyl) such as 4-(2'-phenoxyethoxy)salicylic acid. By using this hydrate as an electron accepting compound, heat-sensitive recording materials excellent in the preservability (e.g. heat resistance) of their color-undeveloped portions can be obtained. This hydrate can be obtained by reaction of an alkali metal salt of the compound of the formula with a water-soluble zinc compound in the pressure of water. The compound of the formula can be prepared by reaction of 4-hydroxysalicylic acid with the corresponding aryloxyethylating agent using a base as necessary, in the presence of a solvent.