Inkjet ink composition, inkjet recording method, ink set, decorative sheet, decorative sheet molded product, process for producing in-mold molded article, and in-mold molded article

1. An inkjet ink composition comprising:

a maleimide-styrene copolymer having an ammonium salt structure, as Component A;

an N-vinyl compound, as Component B;

a colorant, as Component C; and

a photopolymerization initiator, as Component D, wherein the Component A is a copolymer having at least a structure represented by Formula (A-1) below,

wherein in Formula (A-1) above R 1 denotes an alkylene group, the R 2 s independently denote a hydrogen atom or a methyl group, R 3 denotes a hydrogen atom or an alkyl group, R 4 denotes an alkylene group, X + denotes a quaternary ammonium group, Z − denotes a counteranion, n1, n2, and n3 independently denote the molar ratio of the respective constituent unit, (n1):(n2+n3)=1:99 to 99:1 is satisfied, n2:n3=1:99 to 99:1 is satisfied, and n4 denotes an integer of 1 or greater.

2. The inkjet ink composition according to claim 1 , wherein the Component A has a weight-average molecular weight of 1,500 to 10,000.

3. The inkjet ink composition according to claim 1 , wherein the Component A has an ethylene oxide structure and/or a propylene oxide structure.

4. The inkjet ink composition according to claim 1 , wherein the Component A has a content of 0.01 to 5 mass % relative to the total mass of the inkjet ink composition.

5. The inkjet ink composition according to claim 1 , wherein the Component B has a content of 1 to 40 mass % relative to the total mass of the inkjet ink composition.

6. The inkjet ink composition according to claim 1 , wherein the Component C is a quinacridone pigment.

7. The inkjet ink composition according to claim 1 , wherein the Component B is N-vinylcaprolactam.

8. The inkjet ink composition according to claim 1 , wherein the Component D comprises an acylphosphine oxide compound.

9. The inkjet ink composition according to claim 1 , wherein the inkjet ink composition comprises a monomer having a viscosity at 25° C. of no greater than 10 mPa·s, as Component E, in an amount of at least 30 mass % relative to the total mass of the inkjet ink composition.

10. The inkjet ink composition according to claim 9 , wherein the Component E comprises at least one type of compound selected from the group of compounds below

wherein R in the compounds denotes an alkyl group having 4 to 18 carbons.

11. An ink set comprising the inkjet ink composition according to claim 1 .

12. An inkjet recording method comprising:

(a1) step of discharging the inkjet ink composition according to claim 1 onto a resin sheet by an inkjet method, and

(b1) a step of curing the inkjet ink composition by irradiating the discharged inkjet ink composition with actinic radiation.

13. The inkjet recording method according to claim 12 , wherein a light source for the actinic radiation is a light-emitting diode.

14. A decorative sheet comprising an image layer provided above a resin sheet by curing the inkjet ink composition according to claim 1 .

15. A decorative sheet molded product obtained by subjecting the decorative sheet according to claim 14 to vacuum forming, pressure forming, or vacuum/pressure forming.

16. The decorative sheet molded product according to claim 15 , wherein the decorative sheet molded product is further subjected to hole making and/or cutting subsequent to the vacuum forming, pressure forming, or vacuum/pressure forming.

17. A process for producing an in-mold molded article, comprising

a step of placing the decorative sheet according to claim 14 on an inner wall of a cavity part formed by a plurality of molds, and

a step of injecting a molten resin into the cavity part via a gate.

18. A process for producing an in-mold molded article, comprising

a step of placing the decorative sheet molded product according to claim 15 on an inner wall of a cavity part formed by a plurality of molds, and

a step of injecting a molten resin into the cavity part via a gate.