The present invention provides an active energy ray-curable ink composition for offset printing which can maintain excellent drying characteristics with a small dose of UV light. An active energy ray-curable ink composition for offset printing comprising a compound having an ethylenically unsaturated bond, a photopolymerization initiator, and an epoxidized fat or oil is used. Although epoxidized fat or oil is not polymerized through radical polymerization, the present inventors, who have conducted research, have revealed that the reactivity of a radically polymerizable ink composition is increased through addition of epoxidized fat or oil thereto.

A method for producing a printed item including discharging two or more inks by an inkjet method toward a recording medium to form an image is disclosed, wherein the two or more inks include a first oil-based inkjet ink containing a first colorant and a non-aqueous solvent and having an ink surface tension of less than 27.0 mN/m, and a second oil-based inkjet ink containing a second colorant and a non-aqueous solvent and having an ink surface tension of 27.0 mN/m or greater, and the method includes discharging the first oil-based inkjet ink toward the recording medium at a discharge volume of at least 20 pl per one liquid droplet to form dots with the first oil-based inkjet ink, and subsequently discharging the second oil-based inkjet ink toward the recording medium at a discharge volume of less than 20 pl per one liquid droplet so as to overlap with the dots formed with the first oil-based inkjet ink.

A method for producing a printed item including discharging two or more inks by an inkjet method toward a recording medium to form an image is disclosed, wherein the two or more inks include a first oil-based inkjet ink containing a first colorant and a non-aqueous solvent and having an ink surface tension of less than 27.0 mN/m, and a second oil-based inkjet ink containing a second colorant and a non-aqueous solvent and having an ink surface tension of 27.0 mN/m or greater, and the method includes discharging the first oil-based inkjet ink toward the recording medium at a discharge volume of at least 20 pl per one liquid droplet to form dots with the first oil-based inkjet ink, and subsequently discharging the second oil-based inkjet ink toward the recording medium at a discharge volume of less than 20 pl per one liquid droplet so as to overlap with the dots formed with the first oil-based inkjet ink.

[Object] To provide an active energy ray-curable ink composition for offset printing capable of achieving superior gloss of printed matter.

[Solution] An ink composition comprises a compound having at least one ethylenically unsaturated bond and a photopolymerization initiator, wherein a group of material having no ethylenically unsaturated bond, having a specified SP value, and exhibiting a liquid state at room temperature is added to the ink composition up to the upper limit depending on the SP value. Examples of such a group of materials include castor oil, hardened castor oil, polymerized castor oil, coconut oil, palm kernel oil, epoxidized fats and oils, alkylphenols having C15-C18 alkyl groups, cashew nut shell liquid, polymers of cashew nut shell, and modified derivatives of cashew nut shell liquid.

A pigment dispersion containing a metal pigment, wherein the metal pigment contains plate-like particles, and in the case where the longitudinal diameter on the planar surface of the plate-like particle is X, the lateral diameter is Y, and the thickness is Z, the 50% average particle diameter R50 of a corresponding circle determined from the surface area in the X-Y plane of the plate-like particle is between 0.5 and 3 m, and the condition R50/Z>5 is satisfied.

A pigment dispersion containing a metal pigment, wherein the metal pigment contains plate-like particles, and in the case where the longitudinal diameter on the planar surface of the plate-like particle is X, the lateral diameter is Y, and the thickness is Z, the 50% average particle diameter R50 of a corresponding circle determined from the surface area in the X-Y plane of the plate-like particle is between 0.5 and 3 m, and the condition R50/Z>5 is satisfied.

Ink formulations suitable for deposition upon the intermediate transfer member of an indirect printing system and for transfer therefrom to a substrate. The inks are aqueous inkjet inks comprising an organic polymeric resin and a colorant. Ink film constructions including a plurality of continuous ink films fixedly adhered to the printing substrate that can be obtained with these inks are also disclosed. The inks and the printed constructions are such that the ink films and the dried inks composing them have a first dynamic viscosity within a range of 10.sup.6 cP to 5.Math.10.sup.7 cP at at least a first temperature within a first range of 60 C. to 87.5 C., and a second dynamic viscosity of at least 6.Math.10.sup.7 cP, for at least a second temperature within a second range of 50 C. to 55 C.

The present invention provides radiation curable hybrid ink and coating compositions comprising large amounts of inert hard resin. The radiation hybrid ink and coating compositions have good lithographic properties, low roller swelling, and a low gloss-back effect when overprinted with a UV varnish. The ink and coating compositions are useful for lithographic wet and waterless printing.

The present invention provides radiation curable hybrid ink and coating compositions comprising large amounts of inert hard resin. The radiation hybrid ink and coating compositions have good lithographic properties, low roller swelling, and a low gloss-back effect when overprinted with a UV varnish. The ink and coating compositions are useful for lithographic wet and waterless printing.

An ink jet textile printing ink composition includes water; a color material; and a metal chelating agent. In the ink composition described above, the metal chelating agent includes at least one selected from methyl glycine diacetic acid, L-glutamate diacetic acid, L-aspartic diacetic acid, hydroxyethylimino diacetic acid, 3-hydroxy-2,2-iminodisuccucinic acid, dicarboxymethyl glutamic acid, (S,S)-ethylenediaminedisuccinic acid, and salts thereof, and the pH of the ink composition is 6 to 10.