Active ray-curable inkjet ink and image forming method
The present invention relates to: an active ray-curable inkjet ink which has high gloss and is capable of forming an image that is suppressed in gloss difference between itself and a base; and an image forming method which uses this active ray-curable inkjet ink. An active ray-curable inkjet ink according to the present invention contains a photopolymerizable compound, a photoinitiator and a crystalline gelling agent, and is capable of undergoing a sol-gel phase transition. This active ray-curable inkjet ink is characterized by additionally containing a fluorescent bleaching agent.
1. An actinic radiation-curable inkjet ink capable of undergoing sol-gel phase transition, comprising a photocurable compound, a photopolymerization initiator and a crystalline gelling agent,
wherein the actinic radiation-curable inkjet ink further comprises a fluorescent brightener, and the fluorescent brightener is dissolved in the ink.
2. The actinic radiation-curable inkjet ink according to claim 1 , wherein a content of the fluorescent brightener is 0.01 mass % or more and 1.0 mass % or less with respect to a total mass of the actinic radiation-curable inkjet ink.
3. The actinic radiation-curable inkjet ink according to claim 1 , wherein the fluorescent brightener contains a compound represented by the following general formula (1):
wherein R 1 to R 8 each independently represent a hydrogen atom or an alkyl group, and
A represents a linking group represented by any of the following formulas (2) to (5):
wherein each * represents a bonding position of A in each formula.
4. The actinic radiation-curable inkjet ink according to claim 1 , wherein a content of the crystalline gelling agent is 1 mass % or more and 10 mass % or less with respect to a total mass of the actinic radiation-curable inkjet ink.
5. The actinic radiation-curable inkjet ink according to claim 1 , wherein the crystalline gelling agent contains at least one selected from the group consisting of compounds represented by the following general formulas (G1) and (G2):
R 9 —CO—R 10 General formula (G1):
R 11 —COO—R 12 General formula (G2):
wherein R 9 to R 12 each independently represent a straight chain or branched chain hydrocarbon group having 9 or more and 25 or less carbon atoms.
6. The actinic radiation-curable inkjet ink according to claim 1 , further comprising a colorant.
7. The actinic radiation-curable inkjet ink according to claim 1 , wherein the fluorescent brightener is crystalized in the ink in a course of curing the photocurable compound.
8. An image forming method, comprising:
discharging the actinic radiation-curable inkjet ink according to claim 1 from a nozzle of an inkjet recording apparatus and causing the actinic radiation-curable inkjet ink to land on a substrate; and
curing the actinic radiation-curable inkjet ink by irradiating, with actinic radiation, the actinic radiation-curable inkjet ink landed on the substrate.