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US 2025/0051595 A1Published application
Inkjet ink and method of producing the same
AssigneeKYOCERA Document Solutions Inc.
InventorYU KIHARA
Life of this patent
Estimating the term…
Abstract
An inkjet ink includes: an aqueous medium; and a pigment particle dispersed in the aqueous medium. The pigment particle includes a pigment and a cross-linked resin. The cross-linked resin is a cross-linked product of a specific resin, a first cross-linking agent, and a second cross-linking agent. The first cross-linking agent has, in its molecule, an ethylene oxide structure whose number of moles added is 1 or more and 4 or less or a propylene oxide structure whose number of moles added is 1 or more and 4 or less and two or more epoxy groups. The second cross-linking agent has, in its molecule, an ethylene oxide structure whose number of moles added is 5 or more and 15 or less and two or more epoxy groups.
Claims11
An inkjet ink, comprising:
- an aqueous medium;
- and
- a pigment particle dispersed in the aqueous medium,
- the pigment particle including a pigment and a cross-linked resin,
- the cross-linked resin being a cross-linked product of a specific resin, a first cross-linking agent, and a second cross-linking agent,
- the specific resin being a neutralized product of a specific copolymer that includes a first repeating unit derived from α-methylstyrene, a second repeating unit derived from styrene, a third repeating unit derived from (meth)acrylic acid, and a fourth repeating unit derived from alkylene glycol (meth)acrylate or dialkylene glycol (meth)acrylate,
- with respect to 100 mass % of all repeating units included in the specific copolymer,
- a content ratio of the first repeating unit being 1 mass % or more and 65 mass % or less,
- a content ratio of the second repeating unit being 1 mass % or more and 60 mass % or less,
- a content ratio of the third repeating unit being 10 mass % or more and 40 mass % or less,
- a content ratio of the fourth repeating unit being 1 mass % or more and 12 mass % or less,
- an acid value of the specific copolymer being 50 mgKOH/g or more and 300 mgKOH/g or less,
- a mass average molecular weight of the specific copolymer being 3000 or more and 18000 or less,
- a neutralization ratio of the specific resin being 20% or more and 100% or less,
- the first cross-linking agent having, in its molecule, an ethylene oxide structure whose number of moles added is 1 or more and 4 or less or a propylene oxide structure whose number of moles added is 1 or more and 4 or less and two or more epoxy groups,
- water solubility of the first cross-linking agent being 80% or more,
- the second cross-linking agent having, in its molecule, an ethylene oxide structure whose number of moles added is 5 or more and 15 or less and two or more epoxy groups,
- water solubility of the second cross-linking agent being 80% or more,
- a ratio (C2/C1) of a cross-linking rate C2 by the second cross-linking agent to a cross-linking rate C1 by the first cross-linking agent in the cross-linked resin being 18/82 or more and 82/18 or less,
- a total cross-linking rate (C1+C2) by the first cross-linking agent and the second cross-linking agent in the cross-linked resin being 25% or more and 95% or less.
17 more elements
A method of producing an inkjet ink that includes an aqueous medium and a pigment particle dispersed in the aqueous medium, comprising:
- a neutralization step of neutralizing a specific copolymer to obtain a specific resin, the pigment particle including a pigment and a cross-linked resin;
- a dispersion step of dispersing the specific resin and the pigment in water to obtain a pigment particle dispersion liquid;
- and
- a cross-linking step of cross-linking the specific resin in the pigment particle dispersion liquid with a first cross-linking agent and a second cross-linking agent to obtain the cross-linked resin,
- the specific copolymer including a first repeating unit derived from α-methylstyrene, a second repeating unit derived from styrene, a third repeating unit derived from (meth)acrylic acid, and a fourth repeating unit derived from alkylene glycol (meth)acrylate or dialkylene glycol (meth)acrylate,
- with respect to 100 mass % of all repeating units included in the specific copolymer,
- a content ratio of the first repeating unit being 1 mass % or more and 65 mass % or less,
- a content ratio of the second repeating unit being 1 mass % or more and 60 mass % or less,
- a content ratio of the third repeating unit being 10 mass % or more and 40 mass % or less,
- a content ratio of the fourth repeating unit being 1 mass % or more and 12 mass % or less,
- an acid value of the specific copolymer being 50 mgKOH/g or more and 300 mgKOH/g or less,
- a mass average molecular weight of the specific copolymer being 3000 or more and 18000 or less,
- a neutralization ratio of the specific resin in the neutralization step being 20% or more and 100% or less,
- the first cross-linking agent having, in its molecule, an ethylene oxide structure whose number of moles added is 1 or more and 4 or less or a propylene oxide structure whose number of moles added is 1 or more and 4 or less and two or more epoxy groups,
- water solubility of the first cross-linking agent being 80% or more,
- the second cross-linking agent having, in its molecule, an ethylene oxide structure whose number of moles added is 5 or more and 15 or less and two or more epoxy groups,
- water solubility of the second cross-linking agent being 80% or more,
- a ratio (C2/C1) of a cross-linking rate C2 by the second cross-linking agent to a cross-linking rate C1 by the first cross-linking agent in the cross-linking step being 18/82 or more and 82/18 or less,
- a total cross-linking rate (C1+C2) of the cross-linked resin by the first cross-linking agent and the second cross-linking agent being 25% or more and 95% or less.
16 more elements
Dependencies are inferred from the claim text.