Ink composition

1. A liquid electrophotographic ink composition, comprising:

a charge director;

a non-polar carrier fluid comprising a polymer;

ink particles each comprising a polymeric resin and a pigment dispersed in the polymeric resin; and

a tackifier, wherein the tackifier comprises a terpene phenolic resin;

wherein:

the tackifier has a molecular weight Mn of between about 600 and about 1000; or

the tackifier has a softening temperature of about 100° C.

2. The liquid electrophotographic ink composition of claim 1 , wherein the charge director comprises at least one of a lecithin, a sulfonate salt, or a sulfosuccinate salt.

3. The liquid electrophotographic ink composition of claim 1 , wherein the tackifier dissolves completely in an isoparaffin.

4. The liquid electrophotographic ink composition of claim 1 , further comprising a charge adjuvant selected from the group consisting of barium petronate, calcium petronate, Ca salts of naphthenic acid, Cu salts of naphthenic acid, Mn salts of naphthenic acid, Ba salts of stearic acid, Co salts of stearic acid, Pb salts of stearic acid, Zn salts of stearic acid, Al salts of stearic acid, Zn salts of stearic acid, Cu salts of stearic acid, Pb salts of stearic acid, Fe salts of stearic acid, Co lineolates, Mn lineolates, Pb lineolates, Zn lineolates, Ca oleates, Co oleates, Zn palmirate, Ca resinates, Co resinates, Mn resinates, Pb resinates, Zn resinates, AB diblock copolymers of 2-ethylhexyl methacrylate-co-methacrylic acid calcium and ammonium salts, copolymers of an alkyl acrylamidoglycolate alkyl ether and hydroxy bis(3,5-di-tert-butyl salicylic) aluminate monohydrate, and combinations thereof.

5. The liquid electrophotographic ink composition of claim 1 , wherein the polymer of the non-polar carrier fluid is selected from the group consisting of a hydrocarbon, silicone oil, soy bean oil, and vegetable oil.

6. A liquid electrophotographic ink composition, comprising:

a charge director;

a non-polar carrier fluid comprising a polymer;

ink particles each comprising a polymeric resin and a pigment dispersed in the polymeric resin; and

a tackifier, wherein the tackifier comprises a terpene phenolic resin and a dimerized acid rosin.

7. A liquid electrophotographic ink composition, comprising:

a charge director;

a non-polar carrier fluid comprising a polymer;

ink particles each comprising a polymeric resin and a pigment dispersed in the polymeric resin, wherein the polymeric resin comprises a copolymer of ethylene and methacrylic acid; and

a tackifier, wherein the tackifier comprises a terpene phenolic resin.

8. A method of manufacturing a liquid electrophotographic ink composition, the method comprising:

dissolving a tackifier in a non-polar carrier fluid to form a mixture, wherein the non-polar carrier fluid comprises a polymer, and the tackifier comprises a terpene phenolic resin;

combining the mixture with a charge director and ink particles each comprising a polymeric resin and a pigment dispersed in the polymeric resin to form the liquid electrophotographic ink composition;

wherein the tackifier is disposed in the non-polar carrier fluid at between about 1% and about 5% by weight of the fluid.

9. The method of claim 8 , further comprising printing the liquid electrophotographic ink composition, the printing comprising:

disposing the liquid electrophotographic ink composition over a portion of a substrate; and

drying the disposed liquid electrophotographic ink composition to form an image over the portion.

10. A liquid electrophotographic ink composition, comprising:

a charge director;

a non-polar carrier fluid comprising a polymer;

ink particles each comprising a polymeric resin and a pigment dispersed in the polymeric resin; and

a tackifier, wherein the tackifier comprises a terpene phenolic resin, an abietic acid, and a rosin ester.