Abstract: A radiation curable ink jet composition includes polymerizable compounds and a colorant, the polymerizable compounds includes a monofunctional polymerizable compound in an amount of 78 percent by mass or more with respect to a total mass of the polymerizable compounds, and the colorant includes at least one selected from the group consisting of C.I. Pigment Orange 36, C.I. Pigment Orange 38, C.I. Pigment Orange 43, C.I. Pigment Orange 64, C.I. Pigment Orange 71, C.I. Pigment Red 177, C.I. Pigment Red 179, C.I. Pigment Red 224, C.I. Pigment Red 254, C.I. Pigment Red 255, C.I. Pigment Violet 23, C.I. Pigment Violet 32, C.I. Pigment Violet 37, C.I. Pigment Violet 39, C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Blue 15:6, C.I. Pigment Blue 25, and C.I. Pigment Blue 60.

Abstract: An ink jet method includes a step of adhering ink jet compositions containing colorants and polymerizable compounds to be cured with radioactive rays to a recording medium by one printing operation, and the ink jet compositions includes an orange ink composition and a red ink composition.

Abstract: An ink set of radiation curable ink jet compositions, includes: an under layer ink; and an over layer ink, and the under layer ink contains, as a polymerizable compound, 80.0 percent by mass or more of a monofunctional polymerizable compound with respect to a total mass of polymerizable compounds and contains 55.0 percent by mass or more of a polymerizable compound having a nitrogen heterocyclic structure and/or a polymerizable compound having a hydroxy group in total with respect to the total mass of the polymerizable compounds.

Abstract: Provided is an ink set of radiation-curable ink jet compositions each including a polymerizable compound component. The ink set includes a color ink and a clear ink as the radiation-curable ink jet compositions. The polymerizable compound component contained in the clear ink includes a monomer A having a volume of 260 angstrom3 or more and an area of 25 angstrom2 or more in the height direction with respect to a long side defined by a van-der-Waals radius, and the content of the monomer A contained in the clear ink is 80 mass % or more based on the total amount of the polymerizable compound component.

Abstract: An ink set of a radiation-curable ink jet composition containing a polymerizable compound, wherein the ink set includes a color ink and a clear ink as the radiation-curable ink jet composition, the polymerizable compound contained in the clear ink contains at least one of Polymerizable monomer A1 and Polymerizable oligomer A2, Polymerizable monomer A1 having a volume of 0.26 nm3 or more and an area in the direction of the height relative to a long side of 0.25 nm2 or more that are defined by using the van-der-Waals radius, and a total content of Polymerizable monomer A1 and Polymerizable oligomer A2 contained in the clear ink is 80% by mass or more relative to a total amount of the polymerizable compound.

Abstract: An ink jet method records a radiation-curable ink composition containing a polymerizable compound. The radiation-curable ink composition includes a first ink composition and a second ink composition. The ink jet method includes a first discharging step of discharging the first ink composition with an ink jet head to adhere the composition to a recording medium, a first curing step of irradiating the first ink composition adhered to the recording medium with radioactive rays, a cooling step of cooling the recording medium, a second discharging step of discharging the second ink composition with the ink jet head to adhere the composition to the cooled recording medium at least in a part of the region where the first ink composition adhered; and a second curing step of irradiating the second ink composition adhered to the recording medium with radioactive rays.

Abstract: An ink jet method includes an ejecting step of ejecting a radiation-curable ink jet composition from an ink jet head and an irradiating step of irradiating the ejected radiation-curable ink jet composition with an ultraviolet ray at an irradiation intensity of 3 to 10 W/cm2 by using a light emitting diode. The radiation-curable ink jet composition contains monofunctional monomers including a nitrogen-containing monofunctional monomer. The amount of the nitrogen-containing monofunctional monomer relative to the total amount of the radiation-curable ink jet composition is 5 to 40 mass %.

Abstract: A radiation-curable ink jet composition comprises a polymerizable compound component including a monofunctional monomer component and a multifunctional monomer component. The content of the monofunctional monomer component is 87 mass % or more based on the polymerizable compound. The monofunctional monomer component includes a nitrogen-containing monofunctional monomer component, and the content of the nitrogen-containing monofunctional monomer component is 14 mass % or less based on total amount of the radiation-curable ink jet composition. The weighted average of the glass transition temperatures of homopolymers of the respective polymerizable compounds is 42° C. or more when the mass ratios of the contents of the respective polymerizable compounds are weighted.

Abstract: A radiation-curable ink jet composition comprises a polymerizable compound component including a monofunctional monomer component and a multifunctional monomer component. The content of the monofunctional monomer component is 87 mass % or more based on the total amount of the polymerizable compound component, the monofunctional monomer component includes a monofunctional acrylate containing a polycyclic hydrocarbon group, and the weighted average of the glass transition temperatures of homopolymers of the respective polymerizable compounds is 42° C. or more when the mass ratios of the contents of the respective polymerizable compounds are weighted.

Abstract: A radiation curable ink jet composition includes polymerizable compounds and a photopolymerization initiator, the polymerizable compounds include a monofunctional monomer, a content of the monofunctional monomer with respect to a total mass of the polymerizable compounds is 90 percent by mass or more, and the photopolymerization initiator includes ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate.

Abstract: An ink jet method includes: a discharging step of discharging a radiation-curable ink jet composition onto a recording medium at an ink weight per dot of 22 ng/dot or less by using an ink jet head having a nozzle density of 600 npi or more and configured to discharge the radiation-curable ink jet composition; and an irradiating step of irradiating, with radiation, the radiation-curable ink jet composition attached to the recording medium. The radiation-curable ink jet composition contains polymerizable compounds containing a monofunctional monomer and a multifunctional monomer. The monofunctional monomer includes a nitrogen-containing monofunctional monomer. The amount of the monofunctional monomer is 90 mass % or more relative to the total amount of the polymerizable compound. The amount of the nitrogen-containing monofunctional monomer is from 1 to 15 mass % relative to the total amount of the polymerizable compounds.

Abstract: An ink jet method includes: a discharging step of discharging a radiation-curable ink jet composition onto a recording medium at an ink weight per dot of 22 ng/dot or less by using an ink jet head configured to discharge the radiation-curable ink jet composition and having a nozzle density of 600 npi or more; and an irradiating step of irradiating, with radiation, the radiation-curable ink jet composition attached to the recording medium. The radiation-curable ink jet composition contains polymerizable compounds including a monofunctional monomer and a multifunctional monomer. The monofunctional monomer includes a nitrogen-containing monofunctional monomer. The amount of the monofunctional monomer is 90 mass % or more relative to the total amount of the polymerizable compounds. The amount of the nitrogen-containing monofunctional monomer is from 1 to 15 mass % relative to the total amount of the polymerizable compounds.

Abstract: A radiation-curable ink jet composition includes vinyl methyl oxazolidinone and a vinyl ether group-containing (meth)acrylate represented by the following formula (1): H2C?CR1—CO—OR2—O—CH?CH—R3 (where, R1 is a hydrogen atom or a methyl group, R2 is a divalent C2-C20 organic residue, and R3 is a hydrogen atom or a monovalent C1-C11 organic residue).

Abstract: A radiation-curable ink jet composition includes a monofunctional (meth)acrylate monomer and vinyl methyl oxazolidinone.

Abstract: An ink set of radiation curable ink jet inks each of which contains polymerizable compounds, includes a color ink and a clear ink, the polymerizable compounds contained in the clear ink include a monomer A having a hydroxy group and a monomer B having a volume of 0.26 nm3 or more and a height direction area of 0.25 nm2 or more with respect to a long side each of which is defined by the Van der Waals radii, and a total content of the monomer A and the monomer B is 80 percent by mass or more with respect to a total mass of the polymerizable compounds contained in the clear ink.

Abstract: A radiation-curable ink jet composition includes monomers, the monomers including 86% by mass or more of one or more monofunctional monomers relative to all the monomers, where a glass transition temperature of the radiation-curable ink jet composition calculated from glass transition temperatures of all the monomers is 42° C. or higher.

Abstract: Provided is an ink set of radiation-curable ink jet compositions each including a polymerizable compound component. The ink set includes a color ink and a clear ink as the radiation-curable ink jet compositions. The polymerizable compound component contained in the clear ink includes a monomer A having a volume of 260 angstrom3 or more and an area of 25 angstrom2 or more in the height direction with respect to a long side defined by a van-der-Waals radius, and the content of the monomer A contained in the clear ink is 80 mass % or more based on the total amount of the polymerizable compound component.

Abstract: A radiation-curable ink jet composition includes a polymerizable compound component including a monofunctional monomer component and a multifunctional monomer component, a photopolymerization initiator, and titanium oxide as a white color material. The content of the monofunctional monomer component is 90 mass % or more based on the total amount of the polymerizable compound component, and the weighted average of the glass transition temperatures of homopolymers of the respective polymerizable compounds is 48° C. or more when the mass ratios of the contents of the respective polymerizable compounds are weighted.

Abstract: A radiation-curable ink jet composition that is a white ink containing a white coloring material or a pale or clear ink containing 1.2% by mass or less of a coloring material contains at least one polymerizable compound including at least one of a monofunctional monomer having a nitrogen-containing heterocyclic structure and a monomer having a hydroxy group. In the composition, the thioxanthone-based photopolymerization initiator content is limited to 0.3% or less relative to the total mass of the radiation-curable ink jet composition.

Abstract: A radiation-curable ink jet composition comprises a polymerizable compound component including a monofunctional monomer component and a multifunctional monomer component. The content of the monofunctional monomer component is 87 mass % or more based on the polymerizable compound. The monofunctional monomer component includes a nitrogen-containing monofunctional monomer component, and the content of the nitrogen-containing monofunctional monomer component is 14 mass % or less based on total amount of the radiation-curable ink jet composition. The weighted average of the glass transition temperatures of homopolymers of the respective polymerizable compounds is 42° C. or more when the mass ratios of the contents of the respective polymerizable compounds are weighted.