Ink composition, applying system for ink composition, and applying method for ink composition

An applying system for ink composition, comprising:

• an applying apparatus that applies to a workpiece an ink composition comprising at least a photopolymerizable compound and a photopolymerization initiator;
• and
• a light irradiation apparatus that irradiates light to the workpiece applied with the ink composition, wherein:
• the photopolymerizable compound comprises at least one of a multifunctional monomer and a multifunctional oligomer, and a monofunctional monomer,
• at least one of the multifunctional monomer and the multifunctional oligomer is contained in an amount of 20% by weight or more and less than 40% by weight relative to a total weight of the ink composition,
• the monofunctional monomer is contained in an amount of 20% by weight or more and less than 55% by weight relative to the total weight of the ink composition,
• the photopolymerization initiator has a predetermined light absorption spectrum in a wavelength region of 360 nm or more and less than 410 nm, and is contained in an amount of 1% by weight or more and less than 15% by weight relative to the total weight of the ink composition, and
• the light irradiation apparatus comprises at least one of a high pressure mercury lamp, a metal halide lamp, and a UV-LED as a light source.

An applying method for ink composition for applying to a workpiece an ink composition comprising at least a photopolymerizable compound and a photopolymerization initiator to impart decorative properties to the workpiece, the applying method for ink composition comprising:

• applying to the workpiece the ink composition;
• and
• irradiating light to the workpiece applied with the ink composition to cure the ink composition by polymerizing the photopolymerizable compound, wherein:
• the photopolymerizable compound comprises at least one of a multifunctional monomer and a multifunctional oligomer, and a monofunctional monomer,
• at least one of the multifunctional monomer and the multifunctional oligomer is contained in an amount of 20% by weight or more and less than 40% by weight relative to a total weight of the ink composition,
• the monofunctional monomer is contained in an amount of 20% by weight or more and less than 55% by weight relative to the total weight of the ink composition,
• the photopolymerization initiator has a predetermined light absorption spectrum in a wavelength region of 360 nm or more and less than 410 nm, and is contained in an amount of 1% by weight or more and less than 15% by weight relative to the total weight of the ink composition,
• the ink composition is applied on the workpiece by any one of spray applying, coater applying, and inkjet applying, and
• light is irradiated to the workpiece applied with the ink composition from any light source of a high pressure mercury lamp, a metal halide lamp, and a UV-LED.