Ink jet ink composition
AssigneeEastman Kodak Company
InventorsXiaoru Wang, David Erdtmann, Karen J. Klingman
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Abstract
An ink jet ink composition comprising water, a humectant, and composite colorant polymer particles, wherein the composite colorant polymer particles having a colorant phase and a polymer phase, the polymer phase of the particles being formed in situ in the presence of the colorant, the composite colorant polymer particles not increasing in mean particle size more than about 50% when said ink is incubated for one week at 60° C.
Claims14
An ink jet ink composition comprising water, a humectant, and composite pigment polymer particles, wherein said composite pigment polymer particles have a pigment phase and a polymer phase, said polymer phase comprising a polymer formed from
- a) an ethylenically-unsaturated monomer free of ionic charge groups and capable of addition polymerization to form a substantially water-insoluble homopolymer, and
- b) another ethylenically-unsaturated monomer capable of addition polymerization to form a substantially water-soluble homopolymer;
- said particles being formed in situ, wherein a portion of an addition polymerization initiator is added to an aqueous pigment mixture, wherein said aqueous pigment mixture contains no monomer which is used to form the polymer phase, and then adding a monomer mixture of subparagraphs a) and b) for forming the polymer phase to the pigment mixture in a continuous process the ink jet ink composition being stable as defined by said composite pigment polymer particles not increasing in mean particle size more than about 18% when said ink jet ink composition is incubated for one week at 60° C., wherein said composite pigment polymer particles have a mean particle size of less than about 80 nm and wherein the ratio of said pigment phase to said polymer phase is from about 30:70 to about 70:30.
An ink jet ink composition comprising water, a humectant, and composite pigment polymer particles, wherein said composite pigment polymer particles have a pigment phase and a polymer phase, said polymer phase of said particles being formed in situ, wherein a portion of an addition polymerization initiator is added to an aqueous pigment mixture wherein no monomer which is used to form the polymer phase is added to the pigment mixture prior to or at the time that a portion of an addition polymerization initiator is first added to the aqueous pigment mixture, and then adding a monomer mixture for forming the polymer phase to the pigment mixture and wherein said aqueous pigment mixture consists essentially of pigment particles, dispersants or surfactants, and water;
- the ink jet ink composition being stable as defined by said composite pigment polymer particles not increasing in mean particle size more than about 18% when said ink jet ink composition is incubated for one week at 60° C., wherein said composite pigment polymer particles have a mean particle size of less than about 80 nm and wherein the ratio of said pigment phase to said polymer phase is from about 30:70 to about 70:30.
An ink jet ink composition comprising water, a humectant, and composite pigment polymer particles, wherein said composite pigment polymer particles have a pigment phase and a polymer phase, said polymer phase of said particles being formed in situ, wherein a first portion of an addition polymerization initiator is added to an aqueous pigment mixture, wherein said aqueous pigment mixture contains no monomer which is used to form the polymer phase followed by adding a monomer mixture for forming the polymer phase to the pigment mixture;
- the ink jet ink composition being stable as defined by said composite pigment polymer particles not increasing in mean particle size more than about 18% when said ink is incubated for one week at 60° C., wherein said composite pigment polymer particles are made by a process comprising in order:
- I) suspending in an aqueous medium, under agitation, finely divided pigment particles to form an aqueous pigment mixture;
- II) adding to said aqueous pigment mixture the first portion of the addition polymerization initiator;
- and
- III) causing said addition polymerization initiator to form a free radical while continuously introducing to said aqueous pigment mixture a monomer mixture comprising:
- a) an addition polymerization initiator, and
- b) at least one ethylenically-unsaturated monomer;
- thereby forming said composite pigment particles having a pigment phase and a polymer phase, wherein said composite pigment polymer particles have a mean particle size of less than about 80 nm and wherein the ratio of said pigment phase to said polymer phase is from about 30:70 to about 70:30.
Dependencies are inferred from the claim text.