Process for producing heat-sensitive recording material
AssigneeNew Oji Paper Co., Ltd.
InventorsKyoko Koyabu, Yasuyoshi Morita
Life of this patent
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Abstract
A heat-sensitive recording material with a satisfactory whiteness and an enhanced heat-sensitivity is produced by a process comprising the steps of preparing a coating liquid containing a dye-precursor dispersion and a color developer dispersion, coating a surface of a sheet substrate with the coating liquid and solidifying the resultant coating liquid layer on the sheet substrate, in which process at least one member of the dye-precursor and the color developer is finely pulverized by at least one dispersing operation, in the presence of a pulverizing medium consisting of a number of solid grains having a diameter of 0.9 mm or less, into fine particles having an average size of 0.7 .mu.m or less.
Claims7
A process for producing a heat-sensitive recording material, comprising the steps of:
- dispersing at least one substantially colorless electron-donating dye-precursor in water to prepare an aqueous dye-precursor dispersion;
- separately dispersing at least one electron-accepting compound capable of a contact-reaction with and color development of the dye-precursor when heated, in water to provide an aqueous color-developer dispersion;
- preparing a coating liquid by mixing together the aqueous dye-precursor dispersion, the aqueous color-developer dispersion and a resinous binder;
- coating at least one surface of a sheet substrate with the coating liquid;
- and
- solidifying the resultant coating liquid layer to form a heat-sensitive recording layer on the sheet substrate,
- wherein at least one member of the dye-precursor and the color developer is finely pulverized into fine particles having an average particle size of 0.7 .mu.m or less, the pulverizing medium comprising at least one member selected from the group consisting of glass beads, zirconia beads, alumina beads, silica beads, ceramic beads, steel beads and titanium beads, by a first dispersing operation using a first pulverizing medium consisting of a number of solid grains having a diameter of 1.0 mm or more, and then a second dispersing operation using a second pulverizing medium consisting of a number of solid grains having a diameter of 0.9 mm or less.
Dependencies are inferred from the claim text.