Dispersion of sensitizer particles for thermosensitive recording medium composed mainly stearic acid amide, preparation process thereof, mixed dispersion composition for thermosensitive recording layer and thermosensitive recording medium

摘要

Process for preparing a dispersion of sensitizer particles for thermosensitive recording medium, mainly consisting of stearic acid amide, comprising: mixing the stearic acid amide with another sensitizer other than stearic acid amide, at least one selected from the group consisting of 1,2-bis (phenoxy) ethane, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (4- methylphenoxy) ethane, p-benzylbiphenyl, oxalate di-p-methylbenzyl, b-naftilbenciléter and diphenyl sulfone in a mass ratio of 95: 5 ~ 51:49, thereby obtaining a mixture; co-melting the obtained mixture to heat water in the dispersed emulsifier, in the conditions of a temperature equal to or less than the boiling point of water and in the pressure range of greater than 0.1 MPa but less than 1 MPa so that the stearic acid amide and the other sensitizer are unified and emulsified particles, or emulsifying a co-melted mixture of stearic acid amide and the other sensitizer unified by co-melting the mixture with heat in conditions of a temperature at or below the boiling point of water and in the pressure range of greater than 0.1 MPa but less than 1 MPa, in particles dispersed in water emulsifier, thereby obtaining an emulsified dispersion; and inactivating the emulsified dispersion cooling rate of 3 ° C / min or higher, thereby crystallizing sensitizer particles from the emulsified particles.