| 摘要 |
PURPOSE:To provide the title compound having excellent color developing property and not changed even after long-time preservation when being used as a color developer for a pressure sensitive copying paper, by bringing a specified styrene derivative into reaction with a salicylic acid ester to obtain a salicylic acid ester resin, hydrolyzing the ester resin, and bringing the hydrolyzate into reaction with a multivalent metal salt. CONSTITUTION:A salicylic acid ester of formula I is brought into reaction with a styrene derivative of formula II to obtain a salicylic acid ester resin, which is hydrolyzed, and the hydrolyzate is brought into reaction with a multivalent metal salt. A color developer sheet using a novel color developer constituted of the multivalent metal compound of the salicylic acid ester resin thus obtained is free of after-yellowing due to light and gases such as nitrogen oxide contained in air, gives developed color images stable to light and plasticizers or the like, is free of lowering in developed color density, and has favorable water resistance. In the formula, R1 is a 1-12C alkyl, aryl or cycloalkyl, each of R2 and R3 is H or methyl, and R4 is H or a 1-4C alkyl. |
