UV-LED ink composition compositions containing a matrix or binder system, one or more colorants, and one or more photo-initiators. In some embodiments, the matrix or binder system is cured using one or more UV-LED sources. In some embodiments, the matrix or binder system contains one or more materials that are polymerized, crosslinked, and/or cured upon exposure to the UV-LED source. This allows the ink composition to be free of any organic solvents. After polymerization and/or crosslinking, the ink is dry. UV-LED ink compositions can be better suited for curing black inks, improve/increase productivity due to its instant on/instant off capability, and produce little or no heat. Such compositions may have environmental benefits as well as the curing process does not produce ozone and requires less exhaust air surrounding the press.

An aqueous inkjet ink containing a pigment, a binder resin, a water-soluble organic solvent, a surfactant and water, wherein the binder resin contains, as structural units, an aqueous resin containing a structure derived from an ethylenically unsaturated monomer containing an acid group and a structure derived from an ethylenically unsaturated monomer containing a hydroxyl group, the resin has a weight average molecular weight of 5,000 to 45,000, and a glass transition temperature of 35 to 110° C., the water-soluble organic solvent contains a first water-soluble organic solvent having an SP value of 8.5 to 13 (cal/cm.sup.3).sup.1/2, and does not contain a second water-soluble organic solvent having a boiling point at 1 atmosphere of 235° C. or higher, and the surfactant contains an acetylene-based surfactant.

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.

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.

A composition for forming a light-emitting device, a method of manufacturing a light-emitting device utilizing the composition, and a light-emitting device manufactured utilizing the composition are provided. The composition includes two or more solvents and a boiling point of a first solvent having the highest boiling point among the two or more solvents is greater than 300° C.

A composition for forming a light-emitting device, a method of manufacturing a light-emitting device utilizing the composition, and a light-emitting device manufactured utilizing the composition are provided. The composition includes two or more solvents and a boiling point of a first solvent having the highest boiling point among the two or more solvents is greater than 300° C.

An ink set includes an inkjet ink and a recording head filling liquid. The inkjet ink includes a pigment, a pigment coating resin, a first alkali metal ion, and water. The recording head filling liquid includes polyethylene glycol, a second alkali metal ion, a surfactant, and water. The polyethylene glycol has a mass average molecular weight of at least 180 and no greater than 800. A content ratio of the surfactant in the recording head filling liquid is greater than 0.00% by mass and no greater than 0.10% by mass. The first and second alkali metal ions each contain at least one of Li.sup.+, Na.sup.+, and K.sup.+.

An ink set includes an inkjet ink and a recording head filling liquid. The inkjet ink includes a pigment, a pigment coating resin, a first alkali metal ion, and water. The recording head filling liquid includes polyethylene glycol, a second alkali metal ion, a surfactant, and water. The polyethylene glycol has a mass average molecular weight of at least 180 and no greater than 800. A content ratio of the surfactant in the recording head filling liquid is greater than 0.00% by mass and no greater than 0.10% by mass. The first and second alkali metal ions each contain at least one of Li.sup.+, Na.sup.+, and K.sup.+.

An object of the present invention is to provide a method of efficiently producing a colorant that can be used for production of a pigment composition or an aqueous pigment dispersion with a small volume-average particle size of a dispersed substance and with fewer coarse particles. The inventor of the present invention has achieved the object by a method of producing a colorant that includes: step 1 of kneading a composition containing a pigment having a primary particle size of 100 nm or more, a liquid medium, and a water-soluble inorganic salt with a processing machine to produce a kneaded product containing a pigment having a primary particle size in a range of 10 nm or more and less than 100 nm; and step 2-1 of mixing the kneaded product, a resin having an anionic group, and a basic compound.

A decorative sheet manufacturing method of the present invention is for manufacturing a frosted glass-like decorative sheet using an inkjet printer including a head unit provided with a plurality of nozzles for jetting liquid droplets of an ultraviolet curable ink and an ultraviolet irradiation unit that moves together with the head unit in a main scanning direction of the head unit and irradiates the liquid droplets jetted from the nozzles and landed on a main surface of a transparent base material with ultraviolet rays, the frosted glass-like decorative sheet having the transparent base material and a plurality of dots formed in a print region on the main surface of the transparent base material and formed of a cured product of the ultraviolet curable ink by carrying out inkjet printing having predetermined printing conditions in a multi-pass manner.