Abstract: Purpose is to provide an inkjet recording method for forming high-quality color image on a thick recording medium having low thermal conductance rate. The present invention is a single-pass inkjet recording method using an ink set including at least two active ray-curing color inks, and a recording medium having thermal conductivity of less than 0.10 W/(m·K) and thickness of 0.4 mm or more. The ink set containing two color inks satisfy only condition (a), and the ink set containing three or more color inks satisfy conditions (a) and (b): (a) most downstream color ink has a gelation temperature which is 3.0° C. to 15.0° C. higher than that of most upstream color ink, and (b) second or subsequent color ink from the most upstream position in conveyance direction has a gelation temperature which is the same as or higher than that of an adjacent color ink at the upstream position.

Abstract: The present invention provides an image forming method capable of suppressing glossiness unevenness in one image with curability of an ink droplet having been caused to land on a recording medium increased. The image forming method includes: preparing an actinic radiation-curable inkjet ink containing a radical polymerizable compound, a photopolymerization initiator, a gelling agent, and a nucleating agent; discharging a droplet of the actinic radiation-curable inkjet ink to cause the droplet to land on a surface of a recording medium; and curing the droplet by irradiating the droplet having been caused to land on the recording medium with actinic radiation. The gelling agent contains, in a molecular structure thereof, a polar group, and a C15-26 alkyl group, the nucleating agent is a (poly)glycerin fatty acid ester, and an oxygen concentration in an atmosphere where irradiation with the actinic radiation is conducted is less than 20 vol %.

Abstract: The present invention provides an image forming method capable of suppressing glossiness unevenness in one image with curability of an ink droplet having been caused to land on a recording medium increased. The image forming method includes: preparing an actinic radiation-curable inkjet ink containing a radical polymerizable compound, a photopolymerization initiator, a gelling agent, and a nucleating agent; discharging a droplet of the actinic radiation-curable inkjet ink to cause the droplet to land on a surface of a recording medium; and curing the droplet by irradiating the droplet having been caused to land on the recording medium with actinic radiation. The gelling agent contains, in a molecular structure thereof, a polar group, and a C15-26 alkyl group, the nucleating agent is a (poly)glycerin fatty acid ester, and an oxygen concentration in an atmosphere where irradiation with the actinic radiation is conducted is less than 20 vol %.

Abstract: Purpose is to provide an inkjet recording method for forming high-quality color image on a thick recording medium having low thermal conductance rate. The present invention is a single-pass inkjet recording method using an ink set including at least two active ray-curing color inks, and a recording medium having thermal conductivity of less than 0.10 W/(m·K) and thickness of 0.4 mm or more. The ink set containing two color inks satisfy only condition (a), and the ink set containing three or more color inks satisfy conditions (a) and (b): (a) most downstream color ink has a gelation temperature which is 3.0° C. to 15.0° C. higher than that of most upstream color ink, and (b) second or subsequent color ink from the most upstream position in conveyance direction has a gelation temperature which is the same as or higher than that of an adjacent color ink at the upstream position.

Abstract: Provided is a method for inkjet image formation using a line head and an activating light beam-curing type ink, characterized in that the duration from the time, from a first ink lands on a recording medium, to the time that the first ink or a second ink of the same color series as the first color lands on the recording medium, is 25 ms or longer; the ink includes a gelling agent in an amount of 0.5-3.0 mass % to the entire mass of the ink; and the complex viscosity of the ink at the temperature at which the ink lands on the recording medium is 50-300 Pa·s. According to this method, even when an inkjet image is formed at high speed using ink that experiences a sol-gel phase transition, an image free from white spots and gloss differences in the overlap areas can be formed.

Abstract: Provided is a method for inkjet image formation using a line head and an activating light beam-curing type ink, characterized in that the duration from the time, from a first ink lands on a recording medium, to the time that the first ink or a second ink of the same color series as the first color lands on the recording medium, is 25 ms or longer; the ink includes a gelling agent in an amount of 0.5-3.0 mass % to the entire mass of the ink; and the complex viscosity of the ink at the temperature at which the ink lands on the recording medium is 50-300 Pa·s. According to this method, even when an inkjet image is formed at high speed using ink that experiences a sol-gel phase transition, an image free from white spots and gloss differences in the overlap areas can be formed.

Abstract: The purpose of the present invention is to provide: an active ray-curable inkjet ink which has good dispersion stability during storage, good surface smoothness when ejected on a recording medium, and does not undergo the bleeding of a fatty acid onto the surface of the ink; and an image formation method using the active ray-curable inkjet ink. The purpose can be achieved by an active ray-curable inkjet ink which contains: a photopolymerizable compound; at least one wax in the total mass of 1 to 8 mass % relative to the whole mass of the ink; and a fatty acid in the total mass of 0.0001 to 0.10 mass % relative to the whole mass of the wax.

Abstract: The purpose of the present invention is to provide: an active ray-curable inkjet ink which has good dispersion stability during storage, good surface smoothness when ejected on a recording medium, and does not undergo the bleeding of a fatty acid onto the surface of the ink; and an image formation method using the active ray-curable inkjet ink. The purpose can be achieved by an active ray-curable inkjet ink which contains: a photopolymerizable compound; at least one wax in the total mass of 1 to 8 mass % relative to the whole mass of the ink; and a fatty acid in the total mass of 0.0001 to 0.10 mass % relative to the whole mass of the wax.