Ink composition, and method of forming pattern, color filter and method of preparing color filter using the same

1. An ink composition comprising:

a binder resin comprising a copolymer of monomers represented by the following Formula 3a and Formula 3b:

wherein n is 2, 3, or 4, and m is 0, 1, or 2;

a multifunctional monomer having an ethylenic unsaturated double bond;

a coloring agent;

a solvent; and

a polymerization initiator represented by the following Formula 1:

wherein each of R 1 , R 2 , and R 3 is independently hydrogen, halogen, a linear, branched or cyclic alkyl group having 1 to 18 substituted or unsubstituted carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 18 substituted or unsubstituted carbon atoms, an alkylcarbonyl group having 2 to 18 substituted or unsubstituted carbon atoms, an alkoxycarbonyl group having 2 to 18 substituted or unsubstituted carbon atoms, a carboxyl group, a mercapto group, a cyano group, a hydroxyl group, a nitro group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted naphthyl group; and

wherein X − is selected from the group consisting of a halogen ion, OH − , ClO 2 − , a sulfonate ion, a sulfate ion, a carbonate ion, a phosphate ion, a fluorophosphate ion, a borate ion, AlCl 4 − , BiF 6 − , a fluoroantimony ion, and a fluoroarsenic ion.

2. The ink composition of claim 1 , wherein the binder resin comprises a copolymer of a monomer having a carboxyl group and a monomer having an unsaturated bond.

3. The ink composition of claim 1 , wherein the copolymer is formed of about 10 wt. % to about 90 wt. % of the compound of Formula 3a and about 90 wt. % to about 10 wt. % of the compound of Formula 3b.

4. The ink composition of claim 1 , wherein the copolymer further comprises a compound having an unsaturated bond.

5. The ink composition of claim 1 , wherein a viscosity of the ink is in a range of about 1 cPs to about 11 cPs.

6. The ink composition of claim 1 , wherein a surface tension of the ink is equal to or less than about 22 dyne/cm.

7. The ink composition of claim 1 , wherein the ink composition comprises about 5 wt. % to about 50 wt. % of the copolymer, about 10 wt. % to about 50 wt. % of the multifunctional monomer having an ethylenic unsaturated double bond, about 5 wt. % to about 70 wt. % of the coloring agent, and about 0.1 wt. % to about 12 wt. % of the polymerization initiator of Formula 1, based on the total 100 wt. % solid content, and comprising about 30 wt. % to about 90 wt. % of the solvent, based on the total 100 wt. % content of the composition.

8. The ink composition of claim 7 , wherein the polymerization initiator of Formula 1 is included at a content of about 0.8 wt. % to about 6.5 wt. %, based on the total 100 wt. % solid content.

9. The ink composition of claim 1 , wherein the positive ion of the polymerization initiator of Formula 1 is selected from the group consisting of triphenylsulfonium, tris(4-tolyl)sulfonium, benzylmethyl(4-hydroxyphenyl)sulfonium, benzylmethyl(4-acetoxyphenyl)sulfonium, and methyl(4-hydroxyphenyl)(2-methylphenyl)sulfonium.

10. The ink composition of claim 9 , wherein the ink composition comprises about 10 wt. % to about 50 wt. % of the binder resin, about 10 wt. % to about 50 wt. % of the multifunctional monomer having an ethylenic unsaturated double bond, about 5 wt. % to about 60 wt. % of the coloring agent, and about 0.1 wt. % to about 15 wt. % of the polymerization initiator of Formula 1, based on the total 100 wt. % solid content, and comprises about 40 wt. % to about 90 wt. % of the solvent, based on the total 100 wt. % content of the composition.

11. The ink composition of claim 10 , wherein the polymerization initiator of Formula 1 is included at a content of about 2.3 wt. % to about 9.5 wt. %, based on the total 100 wt. % solid content.

12. The ink composition of claim 10 , further comprising: about 0.1 wt. % to about 25 wt. % of at least one additive selected from the group consisting of a surfactant, an adhesion promoter, an antioxidant, a pigment dispersant, a leveling agent and a hardener, based on the total 100 wt. % solid content.

13. An ink composition comprising:

a binder resin comprising a copolymer of monomers represented by the following Formula 2a, Formula 2b, Formula 2c, and Formula 2d:

wherein R 4 is hydrogen, an alkyl group having 1 to 6 substituted or unsubstituted carbon atoms, or an alkenyl group having 2 to 6 substituted or unsubstituted carbon atoms; R 5 is an alkyl group having 1 to 6 substituted or unsubstituted carbon atoms, or an alkenyl group having 2 to 6 substituted or unsubstituted carbon atoms; and R 6 and R 7 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms;

a multifunctional monomer having an ethylenic unsaturated double bond; a coloring agent;

a solvent; and

a polymerization initiator represented by the following Formula 1:

wherein each of R 1 , R 2 , and R 3 is independently hydrogen, halogen, a linear, branched or cyclic alkyl group having 1 to 18 substituted or unsubstituted carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 18 substituted or unsubstituted carbon atoms, an alkylcarbonyl group having 2 to 18 substituted or unsubstituted carbon atoms, an alkoxycarbonyl group having 2 to 18 substituted or unsubstituted carbon atoms, a carboxyl group, a mercapto group, a cyano group, a hydroxyl group, a nitro group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted naphthyl group; and

wherein X − is selected from the group consisting of a halogen ion, OH − , ClO 2 − , a sulfonate ion, a sulfate ion, a carbonate ion, a phosphate ion, a fluorophosphate ion, a borate ion, AlCl 4 − , BiF 6 − , a fluoroantimony ion, and a fluoroarsenic ion.