Ink composition, inkjet recording method, method of producing planographic printing plate, and planographic printing plate

Abstract

The invention provides an ink composition which includes a polymerization initiator, a polymerizable compound, a colorant, and a high molecular compound having a repeating unit represented by the following formula (I). In formula (I), n represents an integer of from 1 to 5.

Description

Claims

1. An ink composition comprising: (A) a polymerization initiator,(B) a polymerizable compound,(C) a colorant, and(D1) a high molecular compound having a repeating unit represented by the following formula (I):

2. The ink composition of claim 1, wherein the content of the high molecular compound having a repeating unit represented by formula (I) is in a range of from 1 to 20 mass % with respect to the total mass of the ink composition.

3. The ink composition of claim 1, wherein the polymerization initiator is a radical polymerization initiator, and the polymerizable compound is a radical polymerizable compound.

4. The ink composition of claim 1, wherein the colorant is either a pigment or an oil-soluble dye.

5. The ink composition of claim 1, wherein the ink composition is used for inkjet recording.

6. An inkjet recording method comprising: discharging the ink composition of claim 1 onto a recording medium; andirradiating active radiation to the discharged ink composition to cure the ink composition.

7. A method of producing a planographic printing plate comprising: discharging the ink composition of claim 1 onto a hydrophilic support; andirradiating active radiation on the discharged ink composition to cure the ink composition and form a hydrophobic image that is formed by curing the ink composition on the hydrophilic support.

8. A planographic printing plate that is produced according to the method of producing a planographic printing plate of claim 7.

9. An ink composition comprising: (A) a polymerization initiator,(B) a polymerizable compound,(C) a colorant, and(D2) at least one compound selected from the group consisting of compounds represented by the following formula (II) and formula (III), wherein the at least one compound is contained in the ink composition in a range of from 3 to 20 mass % with respect to the total mass of the ink composition:

10. The ink composition of claim 9, wherein the polymerization initiator is a radical polymerization initiator, and the polymerizable compound is a radical polymerizable compound.

11. The ink composition of claim 9, wherein the colorant is either a pigment or an oil-soluble dye.

12. An inkjet recording method, comprising ejecting the ink composition of claim 9.

13. An inkjet recording method comprising: discharging the ink composition of claim 9 onto a recording medium; andirradiating active radiation to the discharged ink composition to cure the ink composition.

14. A method of producing a planographic printing plate comprising: discharging the ink composition of claim 9 onto a hydrophilic support; andirradiating active radiation on the discharged ink composition to cure the ink composition and form a hydrophobic image that is formed by curing the ink composition on the hydrophilic support.

15. A planographic printing plate that is produced according to the method of producing a planographic printing plate of claim 15.