Active energy ray-curable inkjet ink composition and printed product
An object of the present invention is to provide: a pigment dispersion liquid for inkjet ink, which is stable for a long period of storage and which increases repellency to ink ejection surface. Disclosed is a pigment dispersion liquid for inkjet ink, comprising: a pigment; a pigment dispersing agent; and a compound having an ethylenically unsaturated double bond, wherein the pigment dispersing agent has an amine value of 20 mgKOH/g or less and an acid value of 10 mgKOH/g or less, contains one or more components selected from the group consisting of: a copolymer having a styrene-derived repeating unit, a repeating unit derived from an unsaturated fatty acid having 12 or more carbon atoms, and a repeating unit derived from a polyalkylene oxide having an ethylenically unsaturated double bond; a specific salt of the copolymer and an amine derivative of the copolymer.
1. An active energy ray-curable inkjet ink composition comprising a pigment, a pigment dispersing agent, a compound having an ethylenically unsaturated double bond, a polymerization inhibitor, and a photopolymerization initiator,
wherein the polymerization inhibitor contains a phenothiazine-type polymerization inhibitor and a nitrosamine-type polymerization inhibitor;
wherein a content of the phenothiazide-type polymerization inhibitor in the inkjet ink composition is 0.001 to 0.2% by mass, and a content of the nitrosamine-type polymerization inhibitor in the inkjet ink composition is 0.001 to 2% by mass;
wherein a molecular weight of the compound having an ethylenically unsaturated double bond is 150 to 400; and
wherein the compound having an ethylenically unsaturated double bond is liquid at 25° C. and used as a dispersion medium.
2. The active energy ray-curable inkjet ink composition according to claim 1 , wherein the compound having an ethylenically unsaturated double bond is a monofunctional (meth)acrylate having only one (meth)acrylate group or a difunctional (meht)acrylate having two (meth)acrylate groups.
3. The active energy ray-curable inkjet ink composition according to claim 1 , wherein the nitrosamine-type polymerization inhibitor is one or more selected from the group consisting of N-nitroso-N-phenylhydroxylamineammonium salt, N-nitroso-N-phenylhydroxylaminealuminum salt, N-nitroso-N-phenylhydroxylarninecerium salt, N-nitroso-N-phenylhydroxylaminesodium salt, N-nitroso-diphenylamine, N-nitroso-N-cyclohexylaniline, N-nitroso-N-methylaniline and N-nitrosodimethylamine.
4. The active energy ray-curable inkjet ink composition according to claim 1 , wherein the phenothiazine-type polymerization inhibitor is one or more selected from the group consisting of phenothiazine, 2-methoxyphenothiazine, 2-cyanophenothiazine, bis(α-methylbenzyl)phenothiazine, 3,7-dioctylphenothiazine and bis(α,α-dimethylbenzyl)phenothiazine.
5. The active energy ray-curable inkjet ink composition according to claim 3 , wherein the phenothiazine-type polymerization inhibitor is one or more selected from the group consisting of phenothiazine, 2-methoxyphenothiazine, 2-cyanophenothiazine, bis(α-methylbenzyl)phenothiazine, 3,7-dioctylphenothiazine and bis(α,α-dimethylbenzyl)phenothiazine.
6. The active energy ray-curable inkjet ink composition according to claim 1 , wherein the photopolymerization initiator is one or more selected from the group consisting of acyl phosphine oxides, α-hydroxyketones and α-aminoalkylphenones.
7. The active energy ray-curable inkjet ink composition according to claim 4 , wherein the photopolymerization initiator is one or more selected from the group consisting of acyl phosphine oxides, α-hydroxyketones and α-aminoalkylphenones.
8. A printed product comprising a layer formed by curing the active energy ray-curable inkjet ink composition defined by claim 1 on a recording medium.