Process for producing 3,5-di(.alpha.-methylbenzyl)salicylic acid derivative, and use of polyvalent-metal-modified product thereof as color developer
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsYoshimitsu Tanabe, Keizaburo Yamaguchi, Akihiro Yamaguchi
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Abstract
A color-developing sheet using, as a color developer, polyvalent-metal-modified products of salicylic acid compounds composed mainly of a 3,5-di(.alpha.-methylbenzyl)salicylic acid derivative obtained by reacting a salicylic acid ester with an .alpha.-methylbenzyl halide in the presence of an acid catalyst and hydrolyzing the reaction product. Said color-developing sheet has excellent color developability at low temperatures and gives a color of excellent water resistance.
Claims15
A color-developing sheet comprising a substrate and, as a color developer, a polyvalent-metal-modified reaction product of a polyvalent metal salt and an .alpha.-methylbenzyl-substituted salicylic acid derivative composition comprising 60-90% by weight of a 3,5-di(.alpha.-methylbenzyl)salicylic acid derivative, which is produced by reacting a salicylic acid ester represented by the formula (I) ##STR3## where R.sub.1 represents an alkyl group, an aralkyl group or a cycloalkyl group each having 1 to 12 carbon atoms, with an .alpha.-methylbenzyl halide represented by the formula (II) ##STR4## where R.sub.2 and R.sub.3 each represent a hydrogen atom or an alkyl group of 1-4 carbon atoms and X represents a halogen atom, in the presence of an acid catalyst and hydrolyzing the resulting 3,5-di(.alpha.-methylbenzyl)salicylic acid ester.
A color-developing sheet comprising a substrate and, as a color developer, a polyvalent-metal-modified reaction product of a polyvalent metal salt and a 3,5-di(.alpha.-methylbenzyl)salicylic acid compound which is produced by reacting a salicylic acid ester represented by the formula (I) ##STR5## where R.sub.1 represents an alkyl group, an aralkyl group, or a cycloalkyl group each having 1 and 12 carbon atoms, with an .alpha.-methylbenzyl halide represented by the formula (II) ##STR6## where R.sub.2 and R.sub.3 each represent a hydrogen atom or an alkyl group of 1-4 carbon atoms and X represents a halogen atom, in the presence of an acid catalyst, separating a resulting 3,5-di(.alpha.-methylbenzyl)salicylic acid ester from the reaction mixture by vacuum distillation and hydrolyzing the 3,5-di(.alpha.-methylbenzyl) salicylic acid ester.
Dependencies are inferred from the claim text.