| 摘要 |
PURPOSE:To suppress after-yellowing during preservation and upon exposure to sunlight and ensure fastness of developed color images, by using a specified salicylic acid resin in which a specified structural unit is linked by an alpha-carbon atom of other structural unit, the other structural unit itself can be linked to a benzene ring thereof by an alpha-carbon atom, and which has a specified weight average molecular weight, and a multivalent metal salt thereof. CONSTITUTION:A salicylic acid resin in which the amount of a structural unit I of formula I is 5-40mol%, the amount of a structural unit II of formula II is 60-95mol%, the structural unit I is linked by an alpha-carbon atom of the structural unit II, the structural unit II can be linked to a benzene ring of the structural unit II by an alpha-carbon atom and which has a weight average molecular weight of 500-10000, a multivalent metal compound of the resin or a color developer for a pressure-sensitive copying paper comprising the multivalent metal compound as an effective constituent is used. The salicylic acid resin can be obtained by the condensation of salicylic acid with at least one benzyl derivative expressed in formula III in the presence of an acid catalyst. |
