PRODUCTION PROCESS OF MULTIVALENT METAL-MODIFIED SALICYLIC ACID RESINS, COLOR-DEVELOPING AGENTS USING THE RESINS AND SUITED FOR USE IN PRESSURE-SENSITIVE COPYING PAPER SHEETS AND PRESSURE-SENSITIVE COPYING PAPER UNITS EMPLOYING THE AGENTS

摘要

ABSTRACTDisclosed herein are novel multivalent metal-modified salicylic acid resins useful as color-developing agents for pressure-sensitive copying paper.They can each be produced by causing a salicylic acidester and a styrene derivative to undergo a Friedel-Crafts reaction in the presence of a strong acidcatalyst, hydrolyzing the resulting salicylic acidester resin, and then reacting the thus-obtainedsalicylic acid resin with a multivalent metal salt.