The present invention relates to a carbon black and to a process to produce such carbon black as well as uses of such carbon black. The present invention further relates to compositions including such carbon black and the use of such compositions.

In one aspect, provided is a method for producing a semiconducting single-walled carbon nanotube dispersion. This method allows semiconducting single-walled carbon nanotubes to be separated from a single-walled carbon nanotube mixture containing semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes in an aqueous medium, and yet requires only an easily available separation agent and a simple operation. One aspect of the present disclosure relates to a method for producing a semiconducting single-walled carbon nanotube dispersion. The method includes (A) preparing a single-walled carbon nanotube dispersion to be separated that contains single-walled carbon nanotubes composed of semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes, an aqueous medium, and a copolymer containing a constitutional unit A derived from a monomer represented by the following formula (1) and a constitutional unit B derived from a monomer represented by the following formula (3), and (B) centrifuging the single-walled carbon nanotube dispersion to be separated and then collecting a supernatant containing the semiconducting single-walled carbon nanotubes from the centrifuged single-walled carbon nanotube dispersion
CH.sub.2?CHCOOM(1)
CH.sub.2?CR.sup.5COO(CH.sub.2CH.sub.2O).sub.qH(3).

An inkjet ink set in which an aqueous yellow ink composition contains at least one of PY17, PY83, PY128, PY155, and PY180; an aqueous magenta ink composition contains at least one of PR146, PR150, PR176, PR185, and PR254; an aqueous cyan ink composition contains PB15:3; an aqueous black ink composition contains PBk7; an aqueous violet ink composition contains PV23; and each of the aqueous inkjet ink compositions contains an aqueous medium and an alkali-soluble or self-emulsifying polyurethane resin as a binder resin. The inkjet ink set has aqueous inkjet ink compositions having excellent laminate strength and heat resistance.

An inkjet ink set in which an aqueous yellow ink composition contains at least one of PY17, PY83, PY128, PY155, and PY180; an aqueous magenta ink composition contains at least one of PR146, PR150, PR176, PR185, and PR254; an aqueous cyan ink composition contains PB15:3; an aqueous black ink composition contains PBk7; an aqueous violet ink composition contains PV23; and each of the aqueous inkjet ink compositions contains an aqueous medium and an alkali-soluble or self-emulsifying polyurethane resin as a binder resin. The inkjet ink set has aqueous inkjet ink compositions having excellent laminate strength and heat resistance.

An ink film construction including: (a) a first printing substrate selected from the group consisting of an uncoated fibrous printing substrate, a commodity coated fibrous printing substrate, and a plastic printing substrate; and (b) an ink dot set contained within a square geometric projection projecting on the first printing substrate, the ink dot set containing at least 10 distinct ink dots, fixedly adhered to a surface of the first printing substrate, all the ink dots within the square geometric projection being counted as individual members of the set, each of the ink dots containing at least one colorant dispersed in an organic polymeric resin, each of the dots having an average thickness of less than 2,000 nm, and a diameter of 5 to 300 micrometers; each ink dot of the ink dots having a generally convex shape in which a deviation from convexity, (DC.sub.dot), is defined by: DC.sub.dot=1AA/CSA, AA being a calculated projected area of the dot, the area disposed generally parallel to the first fibrous printing substrate; and CSA being a surface area of a convex shape that minimally bounds a contour of the projected area; wherein a mean deviation from convexity (DC.sub.dot mean) of the ink dot set is at most 0.05.

An ink film construction including: (a) a first printing substrate selected from the group consisting of an uncoated fibrous printing substrate, a commodity coated fibrous printing substrate, and a plastic printing substrate; and (b) an ink dot set contained within a square geometric projection projecting on the first printing substrate, the ink dot set containing at least 10 distinct ink dots, fixedly adhered to a surface of the first printing substrate, all the ink dots within the square geometric projection being counted as individual members of the set, each of the ink dots containing at least one colorant dispersed in an organic polymeric resin, each of the dots having an average thickness of less than 2,000 nm, and a diameter of 5 to 300 micrometers; each ink dot of the ink dots having a generally convex shape in which a deviation from convexity, (DC.sub.dot), is defined by: DC.sub.dot=1AA/CSA, AA being a calculated projected area of the dot, the area disposed generally parallel to the first fibrous printing substrate; and CSA being a surface area of a convex shape that minimally bounds a contour of the projected area; wherein a mean deviation from convexity (DC.sub.dot mean) of the ink dot set is at most 0.05.

To provide an actinic-ray-curable ink set for ink-jet recording which is excellent in thick-film curability even when a UV-LED lamp is used as a light source, and has uniform curing sensitivity across different colors. The present invention relates to an actinic-ray-curable ink set for ink-jet recording, characterized in that a cyan ink contains a phthalocyanine pigment, a radical polymerizable compound, and less than 10% by mass of a photopolymerization initiator based on the total amount of the cyan ink, a magenta ink contains a quinacridone-based pigment, a radical polymerizable compound, and less than 5% by mass of a photopolymerization initiator based on the total amount of the magenta ink, a yellow ink contains an azo pigment, a radical polymerizable compound, and less than 10% by mass of a photopolymerization initiator based on the total amount of the yellow ink, and a black ink contains a carbon black, a radical polymerizable compound, and less than 12% by mass of a photopolymerization initiator based on the total amount of the black ink.

To provide an actinic-ray-curable ink set for ink-jet recording which is excellent in thick-film curability even when a UV-LED lamp is used as a light source, and has uniform curing sensitivity across different colors. The present invention relates to an actinic-ray-curable ink set for ink-jet recording, characterized in that a cyan ink contains a phthalocyanine pigment, a radical polymerizable compound, and less than 10% by mass of a photopolymerization initiator based on the total amount of the cyan ink, a magenta ink contains a quinacridone-based pigment, a radical polymerizable compound, and less than 5% by mass of a photopolymerization initiator based on the total amount of the magenta ink, a yellow ink contains an azo pigment, a radical polymerizable compound, and less than 10% by mass of a photopolymerization initiator based on the total amount of the yellow ink, and a black ink contains a carbon black, a radical polymerizable compound, and less than 12% by mass of a photopolymerization initiator based on the total amount of the black ink.

The present invention relates to an ink-jet printing method that is capable of obtaining good printed characters or images which are free of occurrence of white lines or streaks irrespective of irradiation with an active energy ray. The present invention provides an ink-jet printing method including the steps of ejecting at least one ink A selected from the group consisting of a black ink and chromatic inks onto a low-liquid absorbing printing medium and then ejecting a white ink thereonto, in which the ink A contains at least one pigment selected from the group consisting of a black pigment and chromatic pigments, and a polymer dispersant containing a constitutional unit derived from a polyalkylene glycol (meth)acrylate; and the white ink contains titanium oxide and a polymer dispersant containing a constitutional unit derived from a polyalkylene glycol (meth)acrylate.

An ink set includes an ink A including water, a first organic solvent, and a first pigment and an ink B including water, a second organic solvent, a second pigment, and a urethane resin particle. The first organic solvent includes at least one of N,N-dimethyl--buthoxy propionamide, N,N-dimethyl--methoxy propionamide, and 3-ethyl-3-hydroxymethyl oxetane and has a mixing solubility parameter A of 10.00 to less than 13.00 and the second organic solvent has a mixing solubility parameter B of 13.00 to 16.00.