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US 7,451,943 B2Granted
Marking liquid method of preparation and product produced thereby
AssigneeResearch Laboratories of Australia PTY Ltd.
InventorHerbert Lee Marko
Life of this patent
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AssigneeResearch Laboratories of Australia PTY Ltd.
InventorHerbert Lee Marko
Estimating the term…
A method of preparation of a liquid electrostatographic toner or liquid ink jet ink which includes the steps of heating a marking particle mix of particles of a resin and a colourant blend in a carrier liquid to a temperature between about the first softening point of the resin and about the second softening point of the resin, maintaining the temperature of the heated marking particle mix for a selected period of time, cooling the marking particle mix to room temperature, and mixing the marking particle mix with high shear. The particle mix can be produced by coarse grinding in a ball mill. The resultant toner or ink has an improved Newtonian like flow behaviour, improved electrical properties, reduced sedimentation and agglomeration and significantly improved optical density and reduced background. The invention also includes toners and inks produced by the method.
A method of preparation of a liquid electrostatographic toner or liquid ink jet ink, the method including the steps of, a) preparing a resin system comprising a resin or resins with optionally a colourant and coarse grinding the resin system, b) milling the coarse ground resin system with a carrier liquid to produce a liquid marking particle mix, c) heating the liquid marking particle mix to a temperature about or greater than the first softening point of the resin system of the marking particle mix and less than about the second softening point of the resin system, d) maintaining the temperature of the heated marking particle mix for a selected period of time, e) cooling the marking particle mix to room temperature, and f) mixing the marking particle mix with high shear.
A method of preparation of a liquid electrostatographic toner or liquid ink jet ink, the method including the steps of, a) heating a marking particle mix including a carrier liquid and a resin which is insoluble in the carrier liquid to a temperature at or about the first softening point of the resin of the marking particle mix to less than about the second softening point of the resin, b) maintaining the temperature of the heated marking particle mix for a selected period of time, c) cooling the marking particle mix to room temperature, and d) mixing the marking particle mix with high shear.
A method of improving the rheology of a liquid electrostatographic toner or liquid ink jet ink including the steps of heating a marking particle mix of particles of a resin and a colourant blend in a carrier liquid to a temperature between about the first softening point of the resin to less than about the second softening point of the resin, maintaining the temperature of the heated marking particle mix for a selected period of time, cooling the marking particle mix to room temperature, and mixing the marking particle mix with high shear.
A method of improving the physical and electrical properties of a liquid electrostatographic toner, the toner comprising particles of a resin and a colourant in a carrier liquid, the method including the steps of heating the toner to a temperature between about the first softening point of the resin to less than about the second softening point of the resin, maintaining the temperature of the toner for a selected period of time, cooling the toner to room temperature, and mixing the toner with high shear.
Dependencies are inferred from the claim text.