According to one embodiment, an ink which can be decolored upon heating is provided. Colored images can be formed with the ink by various methods, such as ink jetting or the like, then later the images can be decolored with heat. An ink according to an embodiment contains a color developable compound, a color developing agent that causes the color developable compound to develop a color, a nonaqueous solvent, and a decoloring agent that is insoluble in the nonaqueous solvent and decolors the color developable compound upon heating.

A near infrared absorbing-fine-particle dispersion liquid having absorption in a near infrared region, having clear contrast, and being applicable to offset printing; a method for producing the same; an anti-counterfeit ink composition using the near infrared absorbing-fine-particle dispersion liquid; and anti-counterfeit printed matter using the near infrared absorbing-fine-particles. The near infrared absorbing-fine-particle dispersion liquid contains a solvent of one or more from vegetable oils or vegetable oil-derived compounds; near infrared absorbing-fine-particles of 2 mass % or more and 25 mass % or less, selected from one or more of hexaboride fine-particles expressed by formula XB.sub.a (where X is one or more kinds of specified elements, and 4.0≤a≤6.2); and a dispersant soluble in solvent and having a fatty acid in its structure, where the viscosity is 180 mPa.Math.s or less. The anti-counterfeit printed matter is excellent in anti-counterfeit effect due to the near infrared absorbing-fine-particles.

Provided is an active energy ray-curable ink composition for offset printing capable of achieving superior gloss of printed matter. The ink composition comprises a compound having at least one ethylenically unsaturated bond and a photopolymerization initiator, wherein a group of materials having no ethylenically unsaturated bonds, 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.

To provide an active energy ray-curable ink composition that increase the content of raw materials derived from biomass and contains a material having superior pigment dispersibility, such as a rosin-modified phenol resin. An active energy ray-curable ink composition containing a compound having one or more ethylenically unsaturated bonds, a specific resin, and a specific liquid ingredient is provided, wherein the specific resin is at least one selected from the group consisting of rosin-modified phenol resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, gilsonite resins, and asphalt resins, and the specific liquid ingredient is fat and oil that is derived from animals or vegetables or a modified product thereof having no ethylenically unsaturated bonds and a solubility parameter value (hereinafter referred to as sp value) of 9.0 (cal/cm.sup.3).sup.1/2 to less than 11.0 (cal/cm.sup.3).sup.1/2 as measured by turbidimetric titration.

To provide an active energy ray-curable ink composition that increase the content of raw materials derived from biomass and contains a material having superior pigment dispersibility, such as a rosin-modified phenol resin. An active energy ray-curable ink composition containing a compound having one or more ethylenically unsaturated bonds, a specific resin, and a specific liquid ingredient is provided, wherein the specific resin is at least one selected from the group consisting of rosin-modified phenol resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, gilsonite resins, and asphalt resins, and the specific liquid ingredient is fat and oil that is derived from animals or vegetables or a modified product thereof having no ethylenically unsaturated bonds and a solubility parameter value (hereinafter referred to as sp value) of 9.0 (cal/cm.sup.3).sup.1/2 to less than 11.0 (cal/cm.sup.3).sup.1/2 as measured by turbidimetric titration.

An electron-beam curable ink or coating for sensitive applications such as food packaging and pharmaceutical packaging. The ink or coating of the invention comprises a high bio-renewable content. A printed article or laminate comprising a cured layer derived from the ink or coating of the invention.

An electron-beam curable ink or coating for sensitive applications such as food packaging and pharmaceutical packaging. The ink or coating of the invention comprises a high bio-renewable content. A printed article or laminate comprising a cured layer derived from the ink or coating of the invention.

An object is to provide a printing ink that has high environmental friendliness and is excellent in quick dry-curability of a coating when a plasma is used as a curing system. A solution is to provide an ink composition for plasma curing including a photocatalyst compound and/or a composite of a metal component and a photocatalyst compound and to provide an additive for an ink composition for plasma curing, the additive including a photocatalyst compound and/or a composite of a metal component and a photocatalyst compound.

An object is to provide a printing ink that has high environmental friendliness and is excellent in quick dry-curability of a coating when a plasma is used as a curing system. A solution is to provide an ink composition for plasma curing including a photocatalyst compound and/or a composite of a metal component and a photocatalyst compound and to provide an additive for an ink composition for plasma curing, the additive including a photocatalyst compound and/or a composite of a metal component and a photocatalyst compound.

An ink composition for use in digital offset printing including at least one component selected from the group consisting of a curable monomer and a curable oligomer; an optional dispersant; an optional photoinitiator; and at least one non-radiation curable additive, wherein the non-radiation curable additive is a detergent or an emulsifying agent, or wherein the non-radiation curable additive functions as a detergent or emulsifying agent when in the presence of a cleaning fluid, and wherein the non-radiation curable additive is a solid at a temperature of from about 20° C. to about 40° C.