Active energy ray-curable inkjet ink, ink container, and inkjet discharging device

1. An active energy ray-curable inkjet ink, comprising:

photopolymerizable compounds,

wherein the photopolymerizable compounds comprise:

at least one monofunctional monomer selected from the group consisting of a monofunctional monomer of which homopolymer has a glass transition temperature of 90° C. or higher, a monofunctional monomer having a ring structure, and a monofunctional monomer of which homopolymer has a glass transition temperature of 90° C. or higher and that has a ring structure; and

urethane (meth)acrylate.

2. The active energy ray-curable inkjet ink according to claim 1 ,

wherein a cured product obtained by discharging the active energy ray-curable inkjet ink onto a base material to form a coated film having an average thickness of 10 μm, and curing the coated film by irradiating it with an active energy ray having a light intensity of 1,500 mJ/cm 2 has stretchability of 100% or greater when the cured product is stretched with a tensile tester at a tension rate of 20 mm/min at a temperature of 180° C., where the stretchability=[length after tensile test−length before tensile test)/(length before tensile test)]×100, and

wherein the cured product has pencil hardness of HB or greater.

3. The active energy ray-curable inkjet ink according to claim 1 ,

wherein the urethane (meth)acrylate has 2 or more unsaturated carbon-carbon bonds and a weight average molecular weight of from 5,000 to 13,000, and

wherein the urethane (meth)acrylate is polyester-based urethane (meth)acrylate, polyether-based urethane (meth)acrylate, or polycarbonate-based urethane (meth)acrylate, or any combination thereof.

4. The active energy ray-curable inkjet ink according to claim 1 ,

wherein the urethane (meth)acrylate is polycarbonate-based urethane (meth)acrylate having 2 or more unsaturated carbon-carbon bonds, and

wherein the at least one monofunctional monomer is acryloyl morpholine.

5. The active energy ray-curable inkjet ink according to claim 1 ,

wherein the active energy ray-curable inkjet ink further comprises one or more kinds of bifunctional photopolymerizable compounds.

6. The active energy ray-curable inkjet ink according to claim 1 ,

wherein the active energy ray-curable inkjet ink is solvent-free.

7. The active energy ray-curable inkjet ink according to claim 1 ,

wherein the active energy ray-curable inkjet ink further comprises a photopolymerization initiator.

8. The active energy ray-curable inkjet ink according to claim 1 ,

wherein the active energy ray-curable inkjet ink further comprises a colorant.

9. An ink container, comprising:

a container; and

an active energy ray-curable inkjet ink contained in the container,

wherein the active energy ray-curable inkjet ink comprises photopolymerizable compounds, and

wherein the photopolymerizable compounds comprise:

at least one monofunctional monomer selected from the group consisting of a monofunctional monomer of which homopolymer has a glass transition temperature of 90° C. or higher, a monofunctional monomer having a ring structure, and a monofunctional monomer of which homopolymer has a glass transition temperature of 90° C. or higher and that has a ring structure; and

urethane (meth)acrylate.

10. An inkjet discharging device, comprising:

an ink container,

wherein the ink container comprises:

a container; and

an active energy ray-curable inkjet ink contained in the container,

wherein the active energy ray-curable inkjet ink comprises photopolymerizable compounds, and

wherein the photopolymerizable compounds comprise:

at least one monofunctional monomer selected from the group consisting of a monofunctional monomer of which homopolymer has a glass transition temperature of 90° C. or higher, a monofunctional monomer having a ring structure, and a monofunctional monomer of which homopolymer has a glass transition temperature of 90° C. or higher and that has a ring structure; and

urethane (meth)acrylate.

11. The inkjet discharging device according to claim 10 ,

wherein the inkjet discharging device comprises:

an ink discharging unit configured to discharge the active energy ray-curable inkjet ink onto a surface of a base material according to an inkjet recording scheme; and

a curing unit configured to cure the active energy ray-curable inkjet ink discharged onto the surface of the base material by irradiating it with an active energy ray.