HEAT DEVELOPED TYPE DIAZO COPYING MATERIAL AND METHOD OF ENCAPSULATING COUPLER USED FOR THIS MATERIAL

摘要

PURPOSE: To provide heat developed type diazo copying material having high coloring property and an excellent shelf life by encapsulating a coupler with alkali soluble resin as a partition wall. CONSTITUTION: A coupler is used being micro-capsuled with a styrene-acrylic acid copolymer or the mixture of a styrene-acrylic acid copolymer and an isobutylene-maleic anhydride copolymer or a styrene-maleic anhydride copolymer as a capsule wall. This micro-capsule is produced by dissolving the coupler in a water insoluble organic solvent together with acetic acid and mixing it in the ammonium solution styrene-acrylic acid copolymer of alkali soluble resin or the mixed solution of the styrene-acrylic acid copolymer and isobutylene- maleic anhydride copolymer or styrene-maleic anhydride copolymer. Heat developed type diazo copying material with high image density and an excellent shelf life can thereby be obtained.