Linear salicylic acid copolymers and their metal salts, production process thereof, color-developing agents comprising metal-resins of the copolymers, and color-developing sheets employing the agents
申请人:MITSUI TOATSU CHEMICALS, Inc.
公开号:EP0233450A2
公开(公告)日:1987-08-26
Disclosed herein are novel linear copolymers having weight average molecular weight of 500 - 30,000 and comprising structural units represented by the following formulae (I), (II), (III) and (IV):
wherein R₁, R₂ and R₃ mean individually an alkyl group having 4 or fewer carbon atoms and R₄ denotes an alkyl, cycloalkyl, aralkyl or phenyl group, and multivalent metal salts thereof in each of which the multivalent metal forms the multivalent metal salt between carboxyl groups within the same molecule of the copolymer or between different molecules of the copolymer; color-developing agents comprising multivalent metal-modified resins of the copolymers; and color-developing sheets obtained by coating the color-developing agents on their surfaces.
本文公开了新型线性共聚物,其重量平均分子量为 500 - 30,000,包含下式 (I)、(II)、(III) 和 (IV) 所代表的结构单元:
其中 R₁、R₂ 和 R₃ 分别表示具有 4 个或更少碳原子的烷基,R₄ 表示烷基、环烷基、芳烷基或苯基,以及多价金属盐,其中多价金属在共聚物的同一分子内或共聚物的不同分子间的羧基之间形成多价金属盐;由共聚物的多价金属改性树脂组成的显色剂;以及通过在其表面涂布显色剂而获得的显色薄片。