Active energy ray curable aqueous ink composition, and inkjet recording method, ink cartridge, recording unit, and inkjet recording apparatus using the same
To provide an active energy ray curable aqueous ink composition exhibiting excellent curing performance by including a water-soluble polymerizable substance with high reactivity and a water-soluble polymerization initiator having high initiation efficiency; and an inkjet recording method, ink cartridge, recording unit, and inkjet recording apparatus all using the active energy ray curable aqueous ink composition. The active energy ray curable aqueous ink composition includes at least water; a polymerizable substance which undergoes radical polymerization by active energy rays; and a polymerization initiator which generates radicals by active energy rays, in which the polymerizable substance is a water-soluble compound having 2 to 6 (meth)acrylic groups; and the polymerization initiator is a water-soluble acylphosphine oxide compound.
1. An active energy ray curable aqueous ink composition comprising at least water, a polymerizable substance which undergoes radical polymerization by an active energy ray, and a polymerization initiator which generates radicals by an active energy ray,
wherein the polymerizable substance is a water-soluble (meth)acrylate compound represented by the following general formula (1):
wherein Z represents a residue of a polyol or an epoxy ester of a polyol having (x1+y1) hydroxyl groups, x1 represents an integer of 0 to 2, y1 represents an integer of 2 to 6, and x1+y1 represents an integer of 2 to 6, R 1 each independently represent a hydrogen atom or a methyl group, and R 2 each independently represent an atomic group A represented by the following formula:
wherein R 3 each independently represent a hydrogen atom or a methyl group, m1 represents an integer of 1 to 5, and n1 represents 0 or 1,
wherein the content of the water is 40 to 90% by mass with respect to the total amount of the aqueous ink composition, and
wherein the polymerization initiator is either one of the following compounds: