Ink composition, inkjet recording method, printed material, method for producing planographic printing plate, and planographic printing plate
An ink composition comprising a triarylsulfonium salt polymerization initiator containing at least one aryl skeleton having an electron attractive group as a substituent, a polymerizable compound, a sensitizing dye, and a colorant.
1 . An ink composition comprising a triarylsulfonium salt polymerization initiator containing at least one aryl skeleton having an electron attractive group as a substituent, a polymerizable compound, a sensitizing dye, and a colorant.
2 . The ink composition according to claim 1 , wherein the triarylsulfonium salt polymerization initiator containing at least one aryl skeleton having an electron attractive group as a substituent is a polymerization initiator having a triaryl sulfonium salt structure, and a total sum of Hammett values of substituents bound to the aryl skeleton is 0.46 or greater.
3 . The ink composition according to claim 2 , wherein each aryl skeleton in the triarylsulfonium salt has a substituent selected from a halogen atom or a group containing a halogen atom.
4 . The ink composition according to claim 1 , wherein the triarylsulfonium salt is substituted by three or more halogen atoms.
5 . The ink composition according to claim 1 , further comprising another polymerization initiator.
6 . The ink composition according to claim 1 , wherein the content of the polymerization initiator is 0.5 to 30% by weight based on the entire solid content of the ink composition.
7 . The ink composition according to claim 1 , wherein the polymerizable compound is a radical-polymerizable compound.
8 . The ink composition according to claim 1 , wherein the polymerizable compound is a cation-polymerizable compound.
9 . The ink composition according to claim 1 , wherein the colorant is a pigment or an oil-soluble dye.
10 . The ink composition according to claim 9 , wherein the colorant is an oil-soluble dye and the oil-soluble dye has an oxidation potential which is higher than 1.0 V (vs SCE).
11 . The ink composition according to claim 1 , wherein the ink composition is an ink composition for inkjet recording.
12 . An inkjet recording method comprising:
ejecting a curable composition onto a recording medium with an inkjet printer; and
irradiating the ejected curable composition with active radiation to cure the composition,
wherein the curable composition comprises a triarylsulfonium salt polymerization initiator containing at least one aryl skeleton having an electron attractive group as a substituent, a polymerizable compound, and a sensitizing dye.
13 . The inkjet recording method according to claim 12 , wherein the triarylsulfonium salt polymerization initiator containing at least one aryl skeleton having an electron attractive group as a substituent is a polymerization initiator having a triaryl sulfonium salt structure, and a total sum of Hammett values of substituents bound to the aryl skeleton is 0.46 or greater.
14 . The inkjet recording method according to claim 13 , wherein each aryl skeleton in the triarylsulfonium salt has a substituent selected from a halogen atom or a group containing a halogen atom.
15 . The inkjet recording method according to claim 12 , wherein the active radiation is emitted by a light-emitting diode which emits ultraviolet rays having an emission peak wavelength of 360 to 420 nm such that the maximum illuminance on the surface of the recording medium is 10 to 1000 mW/cm 2 .
16 . The inkjet recording method according to claim 12 , wherein the curable composition further comprises a colorant.
17 . A printed material obtained by the method of claim 12 .
18 . A method of producing a planographic printing plate, the method comprising:
ejecting the ink composition of claim 1 to a hydrophilic support; and
irradiating the ink composition with radiation to cure the ink composition, thereby forming a hydrophobic region.
19 . A planographic printing plate produced by the method of claim 18.