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.

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: 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: A radiation-curable ink jet composition contains polymerizable compounds including a monofunctional monomer and a multifunctional monomer. The amount of the monofunctional monomer is 90 mass % or more relative to the total amount of the polymerizable compounds. The weighted mean of glass transition temperatures of homopolymers of the polymerizable compounds with the content mass ratio of each of the polymerizable compounds taken as a weight is 42° C. or higher. The weighted means of SP values of the polymerizable compounds with the content mass ratio of each of the polymerizable compounds taken as a weight is from 9.5 to 10.0.

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: 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: An ink jet method uses a liquid jet head that includes a nozzle for discharging a radiation-curable ink jet composition, a pressure chamber to which the radiation-curable ink jet composition is supplied, and a circulation flow passage allowing the radiation-curable ink jet composition in the pressure chamber to circulate. The method includes discharging the heated radiation-curable ink jet composition by the liquid jet head. The radiation-curable ink jet composition includes 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 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; and the viscosity at 40° C. is 10 mPa·s or more.

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 a radiation curing type ink jet ink composition simultaneously satisfying excellent adhesiveness of a cured film to a recording medium, excellent hardenability, and excellent flexibility of the cured film in a well-balanced state. The composition includes a (meth)acrylate monomer A including a vinyl ether group, a monofunctional (meth)acrylate monomer B including a cyclic ether skeleton having two or more ether groups, a monofunctional (meth)acrylate monomer C including an aromatic ring skeleton, and a photopolymerization initiator. The contents of the monomer A, the monomer B, and the monomer C are 5 to 35 mass %, 23 to 55 mass %, and 13 to 46 mass %, respectively, based on the total mass of the composition.

Abstract: A wireless device includes a detecting unit, a sending unit, and a selecting unit. The detecting unit detects, for each communication channel while switching multiple communication channels, interference information. The sending unit sends to a destination wireless device, a packet in which the detected interference information are sequentially stored for each wireless device. The selecting unit receives the packet. When the wireless device does not correspond to the destination wireless device, the selecting unit transfers the packet. When the wireless device corresponds to the destination wireless device, the selecting unit selects, on the basis of the pieces of the interference information that are sequentially stored in the packet and the detected interference information, a communication channel.

Abstract: A wireless device includes a detecting unit, a sending unit, and a selecting unit. The detecting unit detects, for each communication channel while switching multiple communication channels, interference information. The sending unit sends to a destination wireless device, a packet in which the detected interference information are sequentially stored for each wireless device. The selecting unit receives the packet. When the wireless device does not correspond to the destination wireless device, the selecting unit transfers the packet. When the wireless device corresponds to the destination wireless device, the selecting unit selects, on the basis of the pieces of the interference information that are sequentially stored in the packet and the detected interference information, a communication channel.