Hot melt impulse ink jet ink with dispersed solid pigment in a hot melt vehicle
AssigneeDataproducts Corporation
InventorsAn-Chung R. Lin, Theodore M. Cooke
Life of this patent
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Abstract
A novel hot melt ink jet ink is disclosed for use in an impulse ink jet apparatus. The disclosed ink comprises a dispersed solid pigment which is formulated in a wax, or high molecular weight fatty acid or alcohol vehicle to form a hot melt ink which is solid at room temperature. The provision of such a pigment containing ink provides a high quality ink which is stable for long periods of time at relatively high temperatures. In the preferred embodiments, a dispersed graphite in a non-evaporative oil carrier, such as mineral oil, is formulated with candelilla wax, stearic acid and/or behenic acid.
Claims40
A hot melt solid ink for supply to an ink jet apparatus which heats the solid ink to an elevated jetting temperature and supplies it as liquid ink to an impulse ink jet of a small nozzle diameter, said hot melt solid ink comprising:
- a vehicle selected from the group consisting of (i) a wax having a melting temperature above 65.degree. C. and (ii) a C.sub.18 -C.sub.24 fatty acid or alcohol;
- solid pigment as a recording means in an amount of no more than 10 percent of the total weight of said ink and having a particle size sufficiently small so as not to clog the nozzle and so as to minimize the terminal settling velocity of the solid pigment;
- a non-evaporative carrier in which the solid pigment is suspended, the carrier being dispersed through the vehicle and compatible with the vehicle to enable the carrier and pigment to remain dispersed within the vehicle for long periods even at the jetting temperature and to enable the more efficient use of a smaller amount of said solid pigment;
- and
- said hot melt ink having a jetting viscosity of no more than 15 cP at the jetting temperature.
A method of operating an ink jet apparatus of a small nozzle diameter, comprising the steps of:
- (a) heating a hot melt solid ink comprising:
- a vehicle selected from the group consisting of:
- (i) a wax having a melting temperature above 65.degree. C. and
- (ii) a C.sub.18 -C.sub.24 fatty acid or alcohol, and
- a non-evaporative carrier in which a solid pigment, suspended in the carrier, in an amount of no more than 10 percent of the total weight of said ink and having a particle size much smaller than nozzle diameter so as not to clog the nozzle and sufficiently small so as to minimize the terminal settling velocity of the solid pigment, the carrier being dispersed through the vehicle and compatible with the vehicle and thus enables the more efficient use of a smaller amount of said pigment;
- (b) during a printing period discharging droplets of the liquid ink via an impulse ink jet into a nearby print substrate;
- and
- (c) during a standby period maintaining the liquid ink at the elevated temperature in readiness for the next printing period without the pigment settling out or separating from the vehicle.
A hot melt solid ink for supplying to an ink jet apparatus which heats the solid ink to an elevated jetting temperature and supplies it as liquid ink to an impulse ink jet of a small nozzle diameter, said hot melt solid ink comprising:
- a vehicle selected from the group consisting of (i) a wax having a melting temperature above 65.degree. C. and (ii) a C.sub.18 -C.sub.24 fatty acid or alcohol;
- solid pigment as a recording means, having a particle size of no greater than 10 microns and in an amount of no more than 10 percent of the total weight of said ink;
- a non-evaporative carrier in which the solid pigment is suspended, and the carrier being dispersed through the vehicle and compatible with the vehicle to enable the carrier and pigment to remain dispersed within the vehicle for long periods even at the jetting temperature and to enable the more efficient use of a smaller amount of said solid pigment;
- and
- said hot melt ink having a jetting viscosity of no more than 15 cP at the jetting temperature not to exceed 110.degree. C.
A method of operating an ink jet apparatus of a small nozzle diameter, comprising the steps of:
- (a) heating a hot melt solid ink having a viscosity of no more than 15 cP at a jetting temperature of not to exceed 110.degree. C., comprising:
- a vehicle selected from the group consisting of:
- (i) a wax having a melting temperature above 65.degree. C. and
- (ii) a C.sub.18 -C.sub.24 fatty acid or alcohol, and
- a non-evaporative carrier,
- a solid pigment, suspended in the carrier, of a particle size of no greater than 10 microns and in an amount of no more than 10 percent of the total weight of said ink, the carrier being dispersed through the vehicle and compatible with the vehicle and thus enables the more efficient use of a smaller amount of said solid pigment;
- (b) during a printing period discharging droplets of the liquid ink via an impulse ink jet onto a nearby print substrate;
- and
- (c) during a standby period maintaining the liquid ink at the jetting temperature in readiness for the next printing period without the pigment settling out or separating from the vehicle.
Dependencies are inferred from the claim text.