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).

Abstract: An active energy ray-curable ink composition having excellent adhesiveness to various base materials and satisfactory ejection stability is provided. An active energy ray-curable inkjet ink composition comprising polymerizable monomers, the polymerizable monomers comprising 60 to 98% by weight of monofunctional monomers, the monofunctional monomers comprising 25 to 65% by weight of isobornyl acrylate and 12.5 to 69% by weight of N-vinyl caprolactam based on the total amount of the polymerizable monomers.

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 active energy ray-curable ink composition having excellent adhesiveness to various base materials and satisfactory ejection stability is provided. An active energy ray-curable inkjet ink composition comprising polymerizable monomers, the polymerizable monomers comprising 60 to 98% by weight of monofunctional monomers, the monofunctional monomers comprising 25 to 65% by weight of isobornyl acrylate and 12.5 to 69% by weight of N-vinyl caprolactam based on the total amount of the polymerizable monomers.