Abstract: By use of an ultraviolet curable inkjet ink comprising a colorant, a polymerizable monomer having a specific structure, ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and at least one type selected from the group consisting of an acylphosphine oxide photopolymerization initiator different than the ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, a benzophenone photopolymerization initiator, and an indane photopolymerization initiator, wherein the ratio of the content of the polymerizable monomer having the specific structure and the content of the ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is 2:1 to 8.5:1 by mass ratio, the content of a monofunctional monomer in the ultraviolet curable inkjet ink is 25% by mass or less, a printed matter having curability and coating film flexibility can be obtained regardless of the amount applied to a recording medium, and the discharge stability is also excellent.

Abstract: By the use of an ultraviolet curable inkjet ink set for a line head printer comprising a lower layer ink containing a polymerizable monomer having a specific structure, and, a specific photopolymerization initiator, and an upper layer ink containing a polymerizable monomer having a specific structure and a specific photopolymerization initiator, wherein among the lower layer ink and the upper layer ink, one of the inks is a white ink and the other ink is a black ink, a good printed matter having excellent adhesion between a recording medium and the ink layer, and, between different ink layers can be obtained without generating curing wrinkles and curling over time even during high speed printing.

Abstract: By use of an ultraviolet curable inkjet ink comprising a colorant, a polymerizable monomer having a specific structure, ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and at least one type selected from the group consisting of an acylphosphine oxide photopolymerization initiator different than the ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, a benzophenone photopolymerization initiator, and an indane photopolymerization initiator, wherein the ratio of the content of the polymerizable monomer having the specific structure and the content of the ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is 2:1 to 8.5:1 by mass ratio, the content of a monofunctional monomer in the ultraviolet curable inkjet ink is 25% by mass or less, a printed matter having curability and coating film flexibility can be obtained regardless of the amount applied to a recording medium, and the discharge stability is also excellent.

Abstract: By the use of an ultraviolet curable inkjet ink set for a line head printer comprising a lower layer ink containing a polymerizable monomer having a specific structure, and, a specific photopolymerization initiator, and an upper layer ink containing a polymerizable monomer having a specific structure and a specific photopolymerization initiator, wherein among the lower layer ink and the upper layer ink, one of the inks is a white ink and the other ink is a black ink, a good printed matter having excellent adhesion between a recording medium and the ink layer, and, between different ink layers can be obtained without generating curing wrinkles and curling over time even during high speed printing.

Abstract: An active energy ray-curable inkjet ink containing polymerizable compounds and a polymerization initiator, wherein the polymerizable compounds include at least 5 types of polyfunctional polymerizable compounds having molecular weights within a range from 150 to 500, and include substantially no monofunctional polymerizable compounds.

Abstract: An active energy ray-curable inkjet ink containing polymerizable compounds and a polymerization initiator, wherein the polymerizable compounds include at least 5 types of polyfunctional polymerizable compounds having molecular weights within a range from 150 to 500, and include substantially no monofunctional polymerizable compounds.

Abstract: Provided is a non-aqueous maintenance liquid for an active energy ray-curable inkjet ink which can be used as a cleaning liquid for removing the inkjet ink and as a preserving liquid to fill the head when the printer is not in operation. The non-aqueous maintenance liquid for an active energy ray-curable inkjet ink of the present invention comprises a main liquid component, a pigment dispersant resin, and a surface control agent, wherein the main liquid component is an organic solvent and/or an active energy ray-curable compound, and the amount of the surface control agent is 0.01 to 10% by weight in 100% by weight of the maintenance liquid.

Abstract: An active energy ray-curable inkjet ink comprising an organic solvent having a boiling point of 140° C. to 300° C., and a polymerizable monomer containing 2-(2-vinyloxyethoxy)ethyl acrylate, wherein a content of the organic solvent is from 0.1 to 10% by weight with reference to the total weight of the ink, is shown. The ink has extremely high curability and discharge stability, and excellent adhesion to various base materials, and can be suitably used in inkjet printing.

Abstract: To provide an active energy ray-curable inkjet ink set including ink of at least two different colors, wherein a blending amount of a surface tension adjusting agent to be blended in ink of each color is 1.0 to 5.0% by weight with respect to a total amount of the ink of each color, a difference in the blending amount of the surface tension adjusting agent in the ink of each color is 0.5% by weight or less with respect to a total amount of the ink of each color according to an order of printing, and a difference between maximum and minimum in the blending amount of the surface tension adjusting agent in the ink of each color is made to be 2% by weight or less.

Abstract: Provided is a non-aqueous maintenance liquid for an active energy ray-curable inkjet ink which can be used as a cleaning liquid for removing the inkjet ink and as a preserving liquid to fill the head when the printer is not in operation. The non-aqueous maintenance liquid for an active energy ray-curable inkjet ink of the present invention comprises a main liquid component, a pigment dispersant resin, and a surface control agent, wherein the main liquid component is an organic solvent and/or an active energy ray-curable compound, and the amount of the surface control agent is 0.01 to 10% by weight in 100% by weight of the maintenance liquid.

Abstract: The present invention provides an ink composition for use in active energy beam-curable inkjet printing, wherein the ink composition has low viscosity yet exhibits superior curability and superior adhesion to many different substrates, and also exhibits excellent storage stability. An active energy beam-curable inkjet ink composition containing at least polymerizable monomers (A) and a stabilizer (B), and containing essentially no water, the inkjet ink composition containing, as the polymerizable monomers (A), at least a polymerizable monomer (A-1) containing a vinyl ether group and an acryloyl group, and a polymerizable monomer (A-2) containing 2 or more acryloyl groups.

Abstract: The present invention provides an active energy ray-curable inkjet magenta ink composition that achieves excellent color reproducibility and is also excellent in storage stability, and an ink set using the composition. The magenta ink composition according to the present invention contains, as two kinds of quinacridone pigments, (A) unsubstituted quinacridone and (B) 2,9-dimethylquinacridone.

Abstract: Provided is an ink composition used in active energy ray-curable inkjet printing, which has excellent curing property, discharge property, storage stability, and compatibility with various substrates. The inkjet ink composition of the present invention includes at least two types of polymerizable compounds selected from a group consisting of (A) 2-(2-vinyloxyethoxy) ethyl acrylate, (B) N-vinyl caprolactam, and (C) at least one type of bifunctional acrylate monomer including at least a diacrylate having a molecular weight of 250 or less.

Abstract: An ink composition which is used for active energy ray-curable inkjet printing, has excellent curability or adhesiveness to multiple base materials while having low viscosity, and exhibits excellent non-yellowing properties of the printed matter is provided. The composition comprises a polymerizable monomer (A) and photopolymerization initiators (B), the polymerizable monomer comprising 2-(2-vinyloxyethoxy)ethyl acrylate (A-1), and the photopolymerization initiators comprising oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone) (B-1) and other initiator (B-2).

Abstract: The present invention provides an active energy ray-curable inkjet magenta ink composition that achieves excellent color reproducibility and is also excellent in storage stability, and an ink set using the composition. The magenta ink composition according to the present invention contains, as two kinds of quinacridone pigments, (A) unsubstituted quinacridone and (B) 2,9-dimethylquinacridone.

Abstract: Provided is an ink composition used in active energy ray-curable inkjet printing, which has excellent curing property, discharge property, storage stability, and compatibility with various substrates. The inkjet ink composition of the present invention includes at least two types of polymerizable compounds selected from a group consisting of (A) 2-(2-vinyloxyethoxy)ethyl acrylate, (B) N-vinyl caprolactam, and (C) at least one type of bifunctional acrylate monomer including at least a diacrylate having a molecular weight of 250 or less.

Abstract: The present invention provides an ink composition for use in active energy beam-curable inkjet printing, wherein the ink composition has low viscosity yet exhibits superior curability and superior adhesion to many different substrates, and also exhibits excellent storage stability. An active energy beam-curable inkjet ink composition containing at least polymerizable monomers (A) and a stabilizer (B), and containing essentially no water, the inkjet ink composition containing, as the polymerizable monomers (A), at least a polymerizable monomer (A-1) containing a vinyl ether group and an acryloyl group, and a polymerizable monomer (A-2) containing 2 or more acryloyl groups.

Abstract: To provide an active energy ray-curable inkjet ink set including ink of at least two different colors, wherein a blending amount of a surface tension adjusting agent to be blended in ink of each color is 1.0 to 5.0% by weight with respect to a total amount of the ink of each color, a difference in the blending amount of the surface tension adjusting agent in the ink of each color is 0.5% by weight or less with respect to a total amount of the ink of each color according to an order of printing, and a difference between maximum and minimum in the blending amount of the surface tension adjusting agent in the ink of each color is made to be 2% by weight or less.

Abstract: There is provided an inkjet ink which has satisfactory storage stability and inkjet ejection stability, exhibits excellent curability, and is capable of forming high quality images on coated paper by an inkjet system. Disclosed is an active energy ray curable inkjet ink composition comprising: 15-75% by weight of at least one polymerizable bifunctional monomer selected from the group consisting of dipropylene glycol diacrylate and 1,9-nonanediol diacrylate; and 1% by weight to 10% by weight of [4-(methylphenylthio)phenyl]phenylmethanone as a photopolymerization initiator.

Abstract: An ink composition which is used for active energy ray-curable inkjet printing, has excellent curability or adhesiveness to multiple base materials while having low viscosity, and exhibits excellent non-yellowing properties of the printed matter is provided. The composition comprises a polymerizable monomer (A) and photopolymerization initiators (B), the polymerizable monomer comprising 2-(2-vinyloxyethoxy)ethyl acrylate (A-1), and the photopolymerization initiators comprising oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone) (B-1) and other initiator (B-2).