JP2016065137A - Inkjet ink set and image recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set capable of improving the drying speed of inks.SOLUTION: The inkjet ink set includes: inkjet recording inks each containing at least a colorant; and a treatment liquid containing an infrared absorber. The treatment liquid preferably contains, as the infrared absorber, an inorganic material or an organic dye. The ink set preferably includes, as the inkjet recording inks, a cyan inkjet recording ink, a magenta inkjet recording ink, a yellow inkjet recording ink, and a black inkjet recording ink.SELECTED DRAWING: None

Description

  The present invention relates to an ink jet ink set and an image recording apparatus.

Inkjet printing technology has been greatly increasing in recent years in the printing field because it is easy to increase the width and speed.
There is an increasing demand for recording with a water-based inkjet ink on a medium (slowly permeable medium, non-penetrable medium) in which liquid permeation is slow, such as coated paper for printing.

As conventional ink compositions, for example, those described in Patent Documents 1 to 3 are known.
Patent Document 1 includes at least a recording liquid containing at least a colorant and a polymerizable compound and a treatment liquid containing at least one polysiloxane compound and substantially not containing a colorant. A characteristic ink set for inkjet recording is described.
Patent Document 2 discloses a printing method in which color ink, resin ink, and reactive ink are applied to a non-ink-absorbing and low-absorbing recording medium by an inkjet recording method using a water-based ink set to print an image. (1) The water-based ink set causes aggregation of the color ink containing a colorant, the resin ink containing resin particles without containing a colorant, and the constituent components of the color ink and the resin ink. And (2) the color ink contains a water-insoluble colorant, a water-soluble and / or water-insoluble resin component, a water-soluble solvent, and a surfactant, (3) The resin ink includes a water-soluble resin solvent, thermoplastic resin particles that are insoluble in water but compatible with the water-soluble resin solvent, and the total content of the resin particles is included in the color ink. The colorant (4) The reactive ink contains a reactive agent selected from polyvalent metal salts, polyallylamine and derivatives thereof, and a surfactant, and (5) a drying step during and / or after printing. Inkjet recording type printing method characterized by comprising:
In Patent Document 3, a processing liquid used in an inkjet recording apparatus having a step of applying a processing liquid to a recording medium and a step of forming an image by ejecting ink containing a coloring material onto the recording medium. The treatment liquid contains at least a water-soluble flocculant, a surfactant, a water-soluble organic solvent, and water, and the water-soluble organic solvent contained in the treatment liquid is 40% by mass or more based on the total amount of the treatment liquid. Yes, a water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% is contained in an amount of 15% by mass or more with respect to the total amount of the treatment liquid, A treatment liquid characterized by containing a water-soluble organic solvent having a water content of 6 mass% or more and less than 20 mass% in an amount of 40 mass% or more of the entire water-soluble organic solvent is described.

JP 2010-69805 A JP 2010-115854 A JP 2012-171216 A

  An object of the present invention is to provide an ink set capable of improving the drying speed of ink.

The above-described problems of the present invention have been solved by the means described in <1> or <5> below. It is shown below with <2>-<4> which are preferable embodiments.
<1> an inkjet ink set comprising an inkjet recording ink containing at least a colorant and water, and a treatment liquid containing an infrared absorber;
<2> The inkjet ink set according to <1>, wherein the treatment liquid contains an inorganic material as the infrared absorber.
<3> The inkjet ink set according to <1>, wherein the treatment liquid contains an organic dye as the infrared absorber.
<4> The ink set includes, as the ink jet recording ink, cyan ink jet recording ink, magenta ink jet recording ink, yellow ink jet recording ink, and black ink jet recording ink. The inkjet ink set according to any one of <1> to <3>,
<5> Processing liquid discharge means for discharging a processing liquid onto a recording medium by an ink jet method, ink discharge means for discharging ink for ink jet recording onto the recording medium, and infrared rays for the processing liquid attached on the recording medium An image recording apparatus using the ink set according to any one of <1> to <4>, further including an irradiation unit that irradiates.

According to the inventions described in <1> and <4> above, it is possible to provide an ink set capable of improving the drying speed of the ink as compared with the case where only the ink is included.
According to the invention described in the above <2>, it is possible to provide an ink set capable of improving the heat generation of the treatment liquid as compared with the case where the treatment liquid does not contain an inorganic material as an infrared absorber.
According to the invention described in <3>, it is possible to provide an ink set that can make the color of the treatment liquid lighter than when the treatment liquid does not contain an organic dye as an infrared absorber.
According to the invention described in <5>, it is possible to provide an image recording apparatus capable of improving the drying speed of ink as compared with the case where only ink is included.

It is a schematic block diagram which shows an example of the inkjet recording device of this embodiment.

  Hereinafter, this embodiment will be described in detail. In addition, in this embodiment, description with "A-B" showing a numerical range represents the range including not only the range between A and B but A and B which are the both ends.

(Inkjet ink set)
The ink set of the present embodiment includes an ink for inkjet recording (hereinafter, also simply referred to as “ink” or “ink of the present invention”) containing at least a colorant and water, and a treatment liquid containing an infrared absorber. It is characterized by including.

Problems with water-based inks include bleeding, a decrease in optical density, and see-through when the ink permeates along the fibers of the paper.
As countermeasures, many proposals have been made to heat or ventilate ink in order to quickly dry it after landing on the recording medium.
However, as the printing speed increases, there is a problem that the drying speed cannot keep up.
Therefore, it has been proposed to improve the drying speed of the ink by adding an infrared absorbent to the ink and irradiating and heating a laser that is in the absorption band of the infrared absorbent. However, infrared absorbers that can be dissolved / dispersed in water-based ink are limited, and further, dispersion causes a problem that the stability of the ink is remarkably deteriorated.
Therefore, the present inventors separately prepare the inkjet recording ink and the infrared absorbent-containing treatment liquid as an inkjet, and improve the ink drying speed by irradiating infrared rays by ejecting separately to the same location. And an ink set having good storage stability can be provided.
Hereinafter, the ink for ink jet recording and the treatment liquid constituting the ink set of the present embodiment will be described.

<Ink for inkjet recording>
The ink jet ink set of the present embodiment includes ink jet recording ink.
The ink for ink jet recording (ink) used in this embodiment contains at least a colorant and water.
The ink is an aqueous ink containing water, and may contain a water-soluble organic solvent in addition to water.

[Colorant]
The ink used in this embodiment contains a colorant.
As the colorant, a pigment is preferably exemplified.
Examples of the pigment include organic pigments and inorganic pigments, and there are no particular limitations, and known pigments are used.

  Specific examples of the black pigment (black pigment) include Raven7000, Raven5750, Raven5250, Raven5000 ULTRAII, Raven3500, Raven2000, Raven1500, Raven1250, Raven1200, Raven1190, Raven1190, Raven1190, ULTRAII, Raven1170. Manufactured), Regal 400R, Regal 330R, Regal 660R, Mogu L, Black Pearls L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, M 1400 (above, manufactured by Cabot Corporation), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW200, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black S150 Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa), No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical Corporation) and the like, but are not limited thereto.

Specific examples of cyan pigments include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 22, 60, and the like, but are not limited thereto.
Specific examples of the magenta pigment include C.I. I. Pigment Red 5, 7, 12, 48, 48: 1, 57, 112, 122, 123, 146, 168, 177, 184, 202, C.I. I. Pigment Violet 19 and the like, but are not limited thereto.
Specific examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 114, 128, 129, 138, 151, 154, 180, etc. However, it is not limited to these.

  Here, when a pigment is used as the colorant, the ink preferably contains a pigment dispersant. Examples of the pigment dispersant used include a polymer dispersant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

  As the polymer dispersant, a polymer having a hydrophilic structure portion and a hydrophobic structure portion is preferably used. As the polymer having a hydrophilic structure part and a hydrophobic structure part, for example, a condensation polymer and an addition polymer are used. Examples of the condensation polymer include known polyester dispersants. Examples of the addition polymer include addition polymers of monomers having an α, β-ethylenically unsaturated group. By copolymerizing a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group and a monomer having an α, β-ethylenically unsaturated group having a hydrophobic group, A molecular dispersant is obtained. A homopolymer of a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group is also used.

  Monomers having an α, β-ethylenically unsaturated group having a hydrophilic group include monomers having a carboxyl group, a sulfonic acid group, a hydroxyl group, a phosphoric acid group, such as acrylic acid, methacrylic acid, and croton. Acid, itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bis Examples include methacryloxyethyl phosphate, methacryloxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, and diethylene glycol dimethacrylate.

  Examples of the monomer having an α, β-ethylenically unsaturated group having a hydrophobic group include styrene derivatives such as styrene, α-methylstyrene, vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, and alkyl acrylate esters. Methacrylic acid alkyl ester, methacrylic acid phenyl ester, methacrylic acid cycloalkyl ester, crotonic acid alkyl ester, itaconic acid dialkyl ester, maleic acid dialkyl ester and the like.

Examples of preferred copolymers as the polymer dispersant include styrene-styrene sulfonic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, vinyl naphthalene- Maleic acid copolymer, vinyl naphthalene-methacrylic acid copolymer, vinyl naphthalene-acrylic acid copolymer, alkyl acrylate ester-acrylic acid copolymer, alkyl methacrylate ester-methacrylic acid copolymer, styrene-methacrylic acid Alkyl ester-methacrylic acid copolymer, styrene-acrylic acid alkyl ester-acrylic acid copolymer, styrene-methacrylic acid phenyl ester-methacrylic acid copolymer, styrene-methacrylic acid cyclohexyl ester-methacrylic acid copolymer, and These salts It is. Moreover, you may copolymerize the monomer which has a polyoxyethylene group and a hydroxyl group with these polymers.
Among these, the ink used in this embodiment preferably contains a styrene-acrylic acid copolymer neutralized product, and the styrene-acrylic acid copolymer neutralized product is 0% relative to the total weight of the ink. It is preferable to contain 1 to 10% by weight, and more preferably 0.5 to 5% by weight of the neutralized styrene-acrylic acid copolymer based on the total weight of the ink.
As the styrene-acrylic acid copolymer neutralized product, an alkali metal salt of a styrene-acrylic acid copolymer is preferable, and a sodium salt of a styrene-acrylic acid copolymer is more preferable.

  The weight average molecular weight (Mw) of the polymer dispersant is preferably 2,000 or more and 50,000 or less, for example.

A pigment dispersant may be used individually by 1 type, or may use 2 or more types together.
Although the content of the pigment dispersant varies greatly depending on the pigment, it cannot be generally stated, but it is preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the pigment.

Examples of the pigment include a pigment that self-disperses in water (hereinafter also referred to as “self-dispersing pigment”).
The self-dispersing pigment refers to a pigment that has a water-solubilizing group on the pigment surface and disperses in water without the presence of a polymer dispersant. The self-dispersing pigment can be obtained, for example, by subjecting the pigment to surface modification treatment such as acid / base treatment, coupling agent treatment, polymer graft treatment, plasma treatment, oxidation / reduction treatment, and the like.

  As self-dispersing pigments, in addition to pigments that have been surface-modified to the above pigments, Cab-o-jet-200, Cab-o-jet-300, Cab-o-jet-400 manufactured by Cabot Corporation. IJX-157, IJX-253, IJX-266, IJX-273, IJX-444, IJX-55, Cab-o-jet-250C, Cab-o-jet-260M, Cab-o-jet-270Y, Cab -O-jet-450C, Cab-o-jet-465M, Cab-o-jet-470Y, Cab-o-jet-480M, Microjet Black CW-1, CW-2 manufactured by Orient Chemical Industries, Ltd. Commercially available self-dispersing pigments can also be mentioned.

  The self-dispersing pigment is preferably a pigment having at least a sulfonic acid, a sulfonate, a carboxylic acid, or a carboxylate as a functional group on the surface, and at least a carboxylic acid or a carboxylic acid as a functional group on the surface. A pigment having a salt is more preferable.

Here, examples of the pigment include a pigment coated with a resin. This is called a microcapsule pigment, and there are commercially available microcapsule pigments such as those manufactured by DIC Corporation and Toyo Ink Corporation. In addition, it is not restricted to a commercially available microcapsule pigment, You may use the microcapsule pigment produced according to the objective.
Examples of the pigment also include a resin dispersion type pigment in which a polymer compound is physically adsorbed or chemically bonded to the pigment.
In addition to black pigments, cyan, magenta, and yellow primary pigments, specific pigments such as red, green, blue, brown, and white, metallic luster pigments such as gold and silver, and colorless or light colored pigments. Examples include extender pigments and plastic pigments.
Examples of the pigment include particles in which silica, alumina, polymer beads or the like are used as a core, and a dye or pigment is fixed on the surface thereof, an insoluble lake of the dye, a colored emulsion, a colored latex, or the like.

  As colorants, in addition to pigments, other hydrophilic anionic dyes, direct dyes, cationic dyes, reactive dyes, polymer dyes and oil-soluble dyes, wax powders and resin powders colored with dyes And emulsions, fluorescent dyes and fluorescent pigments.

The volume average particle diameter of the colorant is preferably 10 nm or more and 1,000 nm or less.
The volume average particle diameter of the colorant refers to the particle diameter of the colorant itself, or the particle diameter to which the additive has adhered when an additive such as a dispersant is attached to the colorant. The volume average particle size is measured with a Microtrac UPA particle size analyzer UPA-UT151 (manufactured by Microtrac). The measurement was performed by placing 1,000-fold diluted ink in a measurement cell. As input values at the time of measurement, the viscosity of the ink diluent was used as the viscosity, and the refractive index of the particle was used as the particle refractive index.

  The content (concentration) of the colorant is preferably 1 to 25% by weight and more preferably 2 to 20% by weight with respect to the total weight of the ink.

〔water〕
The ink used in this embodiment contains water.
As water, ion-exchanged water, ultrapure water, distilled water, and ultrafiltered water are particularly preferable from the viewpoint of preventing contamination of impurities or generation of microorganisms.

  The water content is preferably 10 to 95% by weight, more preferably 30 to 90% by weight, based on the total weight of the ink.

[Surfactant]
The ink used in the present embodiment preferably contains a surfactant. As the surfactant used in the ink, for example, a surfactant having an HLB (hydrophilic group / hydrophobic group balance “Hydrophile-Lipophile Balance”) value of 14 or less is preferably exemplified. For example, by adjusting the amount of the surfactant having an HLB of 14 or less, the target static surface tension can be easily adjusted. In addition, the ink described above preferably contains two or more surfactants in view of easy preparation to the target dynamic surface tension and further suppresses image peeling. It is more preferable to contain 2 or 3 types, still more preferably 2 types.

The HLB (hydrophilic group / hydrophobic group balance “Hydrophile-Lipophile Balance”) value is defined by the following formula (Griffin method).
・ HLB = 20 × (sum of formula weight of hydrophilic part / molecular weight)

  As the surfactant, an ethylene oxide adduct of acetylene glycol, an ethylene oxide adduct of acetylene alcohol, and a polyether-modified silicone are preferably mentioned, and an ethylene oxide adduct of acetylene glycol and a polyether-modified silicone are more preferred. More preferred are an ethylene oxide adduct of acetylene glycol and an ethylene oxide adduct of acetylene alcohol.

The ethylene oxide adduct of acetylene glycol is, for example, an —O— (CH ₂ CH ₂ O) _n —H structure in which ethylene oxide is added to at least one hydroxyl group of acetylene glycol (for example, n is an integer of 1 to 30) Represents a compound.
Examples of commercially available products of ethylene oxide adducts of acetylene glycol (the numbers in parentheses indicate catalog values of HLB) include, for example, Olphine E1004 (7-9), Olphine E1010 (13-14), Olphine EXP. 4001 (8-11), Olfine EXP. 4123 (11-14), Olfine EXP. 4300 (10-13), Surfinol 104H (4), Surfinol 420 (4), Surfinol 440 (4), Dinol 604 (8) (the above, Nissin Chemical Industry Co., Ltd. product) etc. are mentioned.

The polyether-modified silicone is, for example, a compound in which a polyether group is bonded to a silicone chain (polysiloxane main chain) in a graft form or a block form. Examples of the polyether group include a polyoxyethylene group and a polyoxypropylene group. The polyether group may be, for example, a polyoxyalkylene group in which an oxyethylene group and an oxypropylene group are added in a block form or randomly.
As commercially available products of polyether-modified silicone (the values in parentheses indicate HLB catalog values), Silface SAG002 (12), Silface SAG503A (11), Silface SAG005 (7) Shin Chemical Industry Co., Ltd.).

  Among these, the ink contains, as a surfactant, two or more compounds selected from the group consisting of an acetylene glycol ethylene oxide adduct, an acetylene alcohol ethylene oxide adduct, and a polyether-modified silicone. It is more preferable to contain two or more acetylene glycol ethylene oxide adducts, and it is even more preferable to contain two acetylene glycol ethylene oxide adducts.

  Examples of other surfactants other than those described above include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants.

Examples of the anionic surfactant include alkylbenzene sulfonate, alkylphenyl sulfonate, alkylnaphthalene sulfonate, higher fatty acid salt, sulfate of higher fatty acid ester, sulfonate of higher fatty acid ester, sulfuric acid of higher alcohol ether. Examples thereof include ester salts and sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, and the like.
Among these, as anionic surfactants, dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, monobutylbiphenylsulfonate, dibutylphenylphenol A disulfonic acid salt etc. are mentioned preferably.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, poly Examples thereof include oxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, alkyl alkanol amide, polyethylene glycol polypropylene glycol block copolymer, acetylene glycol and the like.
Among these, nonionic surfactants include polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene Preferable examples include oxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, polyethylene glycol polypropylene glycol block copolymer, and acetylene glycol.

  Other nonionic surfactants include silicone surfactants such as polysiloxane oxyethylene adducts; fluorine surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; Examples thereof include biosurfactants such as spicrispolic acid, rhamnolipid, and lysolecithin.

  The surfactant content in the ink is preferably 0.01 to 20% by weight, more preferably 0.1 to 10% by weight, and more preferably 0.5 to 8%, based on the total weight of the ink. It is more preferable that it is weight%, and it is especially preferable that it is 2-5 weight%. When it is in the above range, preparation to the intended dynamic surface tension is easy, and image peeling is further suppressed.

[Polymer particles]
The ink used in the present embodiment preferably contains polymer particles.
The polymer particles are a component that improves the fixability of an image with ink on a non-permeable recording medium.
Examples of the polymer particles include styrene-acrylic acid copolymer, styrene-acrylic acid-sodium acrylate copolymer, styrene-butadiene copolymer, polystyrene, acrylonitrile-butadiene copolymer, and acrylate copolymer. And particles (latex particles) such as polyurethane, silicon-acrylic acid copolymer, and acrylic-modified fluororesin. Examples of the polymer particles include core / shell type polymer particles having different compositions at the center and outer edge of the particles.

  The polymer particles may be dispersed in the ink using an emulsifier, or may be dispersed in the ink without using an emulsifier. As an emulsifier, a polymer having a hydrophilic group such as a surfactant, a sulfonic acid group, or a carboxyl group (for example, a polymer having a hydrophilic group grafted thereto, a hydrophilic monomer and a hydrophobic portion) Polymers obtained from monomers).

The volume average particle diameter of the polymer particles is preferably 10 nm or more and 300 nm or less, more preferably 10 nm or more and 200 nm or less, from the viewpoint of glossiness and scratch resistance of the image.
The measurement of the volume average particle size of the polymer particles in the present embodiment is performed with a Microtrac UPA particle size analyzer UPA-UT151 (manufactured by Microtrac). The measurement is performed by placing 1,000-fold diluted ink in a measurement cell. As input values at the time of measurement, the viscosity of the ink diluent was used as the viscosity, and the refractive index of the particles was used as the refractive index of the polymer.

The glass transition temperature of the polymer particles is preferably −20 ° C. or higher and 80 ° C. or lower, and more preferably −10 ° C. or higher and 60 ° C. or lower from the viewpoint of image scratch resistance.
The glass transition temperature of the polymer particles is determined from the DSC curve obtained by differential scanning calorimetry (DSC). More specifically, the method for determining the glass transition temperature in JIS K7121-1987 “Method for Measuring Plastic Transition Temperature”. It is calculated | required by description "extrapolated glass transition start temperature" of description.

  The content of the polymer particles is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight, based on the total weight of the ink.

(Water-soluble organic solvent)
The ink in the present embodiment preferably contains a water-soluble organic solvent.
Examples of the water-soluble organic solvent include polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, alcohols, and sulfur-containing solvents. In addition, examples of the water-soluble organic solvent include propylene carbonate and ethylene carbonate.

  Polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2-hexanediol, 1,2,6-hexanetriol, glycerin, trimethylol Examples thereof include sugar alcohols such as propane and xylitol; sugars such as xylose, glucose and galactose.

  Polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, diglycerin. And ethylene oxide adducts.

Examples of the nitrogen-containing solvent include pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, triethanolamine and the like.
Examples of alcohols include ethanol, isopropyl alcohol, butyl alcohol, and benzyl alcohol.
Examples of the sulfur-containing solvent include thiodiethanol, thiodiglycerol, sulfolane, dimethyl sulfoxide and the like.

The water-soluble organic solvent may be contained singly or in combination of two or more.
The content of the water-soluble organic solvent is preferably 0.1 to 60% by weight, more preferably 1 to 50% by weight, and more preferably 5 to 40% by weight with respect to the total weight of the ink. Is more preferable, and it is especially preferable that it is 10 to 30 weight%.

[Other additives]
The ink used in this embodiment may contain other additives than those described above.
There is no restriction | limiting in particular as another additive, A well-known additive is used. Specifically, for example, an ink dischargeability improving agent (polyethyleneimine, polyamines, polyvinylpyrrolidone, polyethylene glycol, ethylcellulose, carboxymethylcellulose, etc.), conductivity / pH adjuster (potassium hydroxide, sodium hydroxide, lithium hydroxide) Etc.), reactive diluents, penetrants, pH buffers, antioxidants, fungicides, viscosity modifiers, conducting agents, chelating agents, ultraviolet absorbers, infrared absorbers, etc. Is mentioned.

[Ink characteristics]
The pH of the ink used in this embodiment is preferably 4 to 10, and more preferably 5 to 9.
As the pH of the ink, a value measured with a pH / conductivity meter (MPC227 manufactured by METTLER TOLEDO) under a temperature of 23 ± 0.5 ° C. and a humidity of 55 ± 5% RH is adopted.
The conductivity of the ink used in the present embodiment is preferably 0.01 to 0.5 S / m, more preferably 0.01 to 0.25 S / m, and 0.01 to 0.20 S. More preferably, it is / m.
The conductivity is measured by MPC227 (pH / Conductivity Meter, manufactured by METTLER TOLEDO).
The viscosity of the ink used in the present embodiment is preferably 1.5 to 30 mPa · s, and more preferably 1.5 to 20 mPa · s.
Viscosity is measured using TV-20 (manufactured by Toki Sangyo Co., Ltd.) as a measuring device, at a measurement temperature of 23 ° C. and a shear rate of 1,400 s ⁻¹ .

<Processing liquid>
The ink-jet ink set of the present embodiment includes a processing liquid.
The treatment liquid used in this embodiment contains an infrared absorber.
In addition, what is contained in the colorant in the said ink shall not be contained in an infrared absorber.

[Infrared absorber]
As the infrared absorber contained in the treatment liquid used in this embodiment, a known infrared absorber can be used without any particular limitation, but from the viewpoint of not preventing the formation of an image with ink, a pigment such as carbon black. Is not preferred.
Moreover, it is preferable to use an inorganic material or an organic dye as the infrared absorber, and it is preferable to use an inorganic material from the viewpoint of the calorific value. The infrared absorber is decomposed by infrared irradiation, and the color of the infrared absorber itself is reduced. From the viewpoint of thinning and preventing the formation of an image with ink, it is preferable to use an organic dye. The inorganic material is preferably a metal oxide, such as antimony tin oxide (ATO) or indium tin oxide (ITO). Preferably exemplified.
Examples of the organic dyes include cyanine dyes, phthalocyanine dyes, merocyanine dyes, squarylium dyes, onium compounds, indolenine cyanine, pyrylium salts, nickel thiolate complexes, and the like, cyanine dyes, phthalocyanine dyes, merocyanine dyes, squarylium dyes, Is preferred.

The content of the infrared absorber is preferably from 0.1 to 5% by weight, more preferably from 0.5 to 3% by weight, based on the total weight of the treatment liquid.
If it is the said range, the emitted-heat amount is sufficient, and since formation of the image by an ink is not prevented, it is preferable.

  Commercially available infrared absorbers can also be used as the infrared absorber, such as NIR series (manufactured by Nagase ChemteX Corporation), KAYASORB series (manufactured by Nippon Kayaku Co., Ltd.), T-1 series (Mitsubishi Materials Electronics). Kasei Co., Ltd.).

〔water〕
In the present invention, the treatment liquid preferably contains water. As water, ion-exchanged water, ultrapure water, distilled water, and ultrafiltered water are particularly preferable from the viewpoint of preventing contamination of impurities or generation of microorganisms.
The water content is preferably 10 to 95% by weight, more preferably 30 to 90% by weight, based on the total weight of the treatment liquid.

(Water-soluble organic solvent)
The treatment liquid preferably contains at least one water-soluble organic solvent in addition to the flocculant and water. The details of the water-soluble organic solvent are the same as those in the ink, and the preferred embodiments are also the same.

[Surfactant]
In the present invention, the treatment liquid preferably contains a surfactant. The details of the surfactant are the same as those in the ink, and the preferred embodiment is also the same.

[Other ingredients]
The treatment liquid can further contain other additives as other components within a range not impairing the effects of the present embodiment. Other additives include, for example, anti-drying agents (wetting agents), anti-fading agents, emulsion stabilizers, penetration enhancers, UV absorbers, antiseptics, fungicides, pH adjusters, surfactants, antifoaming agents. Known additives such as an agent, a viscosity modifier, a dispersant, a dispersion stabilizer, a rust inhibitor, and a chelating agent can be used.

(Image recording device)
The image recording apparatus according to the present embodiment is attached to a processing liquid ejection unit that ejects a processing liquid onto a recording medium by an inkjet method, an ink ejection unit that ejects ink for inkjet recording onto the recording medium, and the recording medium. An irradiation means for irradiating the treatment liquid with infrared rays is included. The processing liquid and the ink for ink jet recording are the processing liquid and the ink for ink jet recording that constitute the ink set of the present embodiment.

<Processing liquid discharge means>
The image recording apparatus of the present embodiment includes a processing liquid discharge unit that discharges a processing liquid onto a recording medium by an ink jet method. Since the image recording apparatus according to the present embodiment includes the processing liquid discharge unit, an image having excellent abrasion resistance can be formed even on a recording medium that is slow to penetrate.
Further, by having the processing liquid discharge means, it is possible to speed up image recording, and an image having excellent abrasion resistance can be obtained even at high speed recording. Even with high-speed recording, it is possible to obtain an image with high density and resolution and excellent drawing performance (for example, reproducibility of fine lines and fine portions).

As described above, the processing liquid ejection unit is provided before the ink ejection unit.
In this specification, “before each means in the apparatus” means a paper feeding side, and “after” means a paper winding side.
The processing liquid discharge means is a means for discharging a processing liquid containing an infrared absorbent that generates heat upon irradiation with infrared light, and is provided in front of the ink discharge means from the viewpoint of image quality. In other words, the ejection unit is a unit that is provided after the processing liquid ejection unit and ejects ink on the processing liquid of the recording medium on which the processing liquid is ejected by the processing liquid ejection unit.

  As a method for discharging the processing liquid in the processing liquid discharging means, an ink jet method is used in order to discharge the processing liquid only to a region where ink is discharged.

The region where the treatment liquid is discharged is a partial application in which the treatment liquid is partially discharged to a region where ink jet recording is performed by the ink discharge means.
Among these, from the viewpoints of suppressing the amount of processing liquid used, reducing the amount of processing liquid remaining on the recording medium, and preventing the evaporation of moisture in the recording medium other than the printing unit, the ink is discharged by the discharging means. It is preferable to apply the treatment liquid only to the region where the liquid is discharged.

〔recoding media〕
The recording medium used in the ink jet recording apparatus of the present embodiment and the ink jet recording apparatus of the present embodiment is not particularly limited, and a known recording medium is used.
In the ink set of the present embodiment, bleeding of an image is suppressed even for a permeable recording medium in which bleeding of the image is likely to occur.
In addition, a plain paper etc. are mentioned as a permeable recording medium. Specifically, the permeable recording medium means a recording medium having a maximum ink absorption amount exceeding 15 ml / m ² within a contact time of 500 ms as measured by a dynamic scanning absorption meter.
On the other hand, examples of the impermeable recording medium include coated paper and resin film. Specifically, the non-permeable recording medium means a recording medium having a maximum ink absorption amount of 15 ml / m ² or less within a contact time of 500 ms as measured by a dynamic scanning absorption meter.

  In the present embodiment, it is particularly preferable to use a non-permeable recording medium as the recording medium. In this embodiment, even when an impermeable recording medium is used as the recording medium, an image having excellent abrasion resistance can be obtained by using the ink and the treatment liquid in combination.

The application amount of the treatment liquid to the recording medium is not particularly limited as long as the amount is large enough to aggregate the ink, from the viewpoint of aggregating the ink, is 0.5g / m ² ~4.0g / m ² it is more preferably ^{preferably, 0.9g / m 2 ~3.75g / m} 2.

<Processing liquid drying means>
Further, in the present embodiment, after the treatment liquid ejection means, the ejection means is provided, and the drying means for heating and drying the treatment liquid on the recording medium after the treatment liquid is applied onto the recording medium and before the ink is ejected. Is preferably provided. By preliminarily heating and drying the treatment liquid before the discharge means, bleeding is prevented and good image quality is obtained.

Heating and drying can be performed by a known heating means such as a heater, an air blowing means such as a dryer, or a combination of these. As the heating method, for example, a method of applying heat with a heater or the like from the side opposite to the treatment liquid application surface of the recording medium, a method of applying warm air or hot air to the treatment liquid application surface of the recording medium, or an infrared heater was used. The heating method etc. are mentioned, You may heat combining these two or more.
In the drying means, the surface temperature of the recording medium is preferably 35 ° C. to 200 ° C., more preferably 40 ° C. to 150 ° C. By setting the temperature in the drying means within the above range, it is preferable that the ink can be dried quickly, while the scorching of the recording medium, the increase in apparatus cost, and the increase in power consumption are suppressed.
The surface temperature of the recording medium is a value measured as follows. First, a radiation thermometer is installed at a location 0.5 m from the drying device of the recording device by the recording medium conveyance distance. Then, the temperature of the non-image recording portion (blank portion) of the recording medium is measured by the radiation thermometer, and the measured temperature is obtained as the surface temperature of the recording medium.

<Ink ejection means>
The image recording apparatus according to the present embodiment includes an ink ejection unit that ejects ink for inkjet recording onto a recording medium. The ink discharge means preferably discharges ink droplets onto a recording medium with an ink jet head.
The ink jet head used for discharging ink droplets is not particularly limited, and a known ink jet head is used. Examples thereof include a piezo ink jet head and a thermal ink jet head.
The ink discharge temperature is not particularly limited and can be adjusted according to the ink used.
In the ink jet recording apparatus of the present embodiment, ink ejection may be performed a plurality of times as necessary. For example, one type of ink may be ejected multiple times to the same location on the recording medium, two or more types of ink may be ejected once, or two or more types of ink may be ejected multiple times. May be.
The ink used in the present embodiment may be used alone or in combination of two or more. For example, when forming a color image, cyan, magenta, yellow, and black inks are preferably used.

In the ink jet recording apparatus of the present embodiment and the ink jet recording apparatus of the present embodiment, the liquid weight per drop of ink droplet is preferably 25 ng or less, more preferably 0.5 ng or more and 20 ng or less, and more preferably 2 ng or more. More preferably, it is 15 ng or less. In the above embodiment, the drying property is excellent, and the occurrence of peeling in the image is further suppressed.
In the ink jet apparatus capable of ejecting a plurality of drops from one nozzle, the liquid mass per drop refers to the minimum drop amount that can be printed.

In the ink jet recording apparatus of the present embodiment and the ink jet recording apparatus of the present embodiment, the replenishment (supply) of ink to the ink jet head is preferably performed from an ink tank containing ink. The ink tank is preferably of a cartridge type that can be attached to and detached from the apparatus, and ink can be easily replenished by replacing the cartridge type ink tank.
The ink supply system preferably includes, for example, an original tank containing ink, a supply pipe, an ink tank immediately before the inkjet head, a filter, and a piezo-type inkjet head.

<Irradiation means>
The image recording apparatus according to the present embodiment includes an irradiating unit that irradiates infrared rays onto the processing liquid attached on the recording medium.
The irradiation unit is a unit that irradiates the treatment liquid with infrared rays having a wavelength of at least 750 to 1,200 nm, and dries the formed image.
In the irradiating means, it is preferable to irradiate infrared rays to at least the region where the treatment liquid adheres, and from the viewpoint of simplicity, it is more preferable to irradiate the entire surface with infrared rays.
As the infrared irradiation device, known devices can be used without any particular limitation. For example, a device composed of a halogen lamp and a reflection mirror is preferably used, and other devices such as an infrared laser irradiation device may be arranged. . As for halogen lamps, halogen heaters are incorporated into a reflecting mirror and a heating unit is realized to achieve efficient heating. For example, UH-USC-CL300, UH-USC-CL700, UH-USC-CL1000, UH-USD-CL300, UH-USD-CL700, UH-USD-CL1000, UH-MA1-CL300, UH-MA1-CL700, UH-MA1-CL1000 (all manufactured by USHIO INC.) Etc.
Dose of infrared ray in the irradiation unit is preferably 100~1,000mW / m ^2, more preferably 150~600mW / m ^2, more preferably 200~500mW / m ^2.
The infrared irradiation time is not particularly limited and may be irradiated until the ink is dried, but is preferably 0.1 second to 3 minutes, more preferably 0.2 seconds to 1 minute, and 0.5 seconds to 30 seconds. Is more preferable.

<Ink drying means>
In the present embodiment, the image recording apparatus may further include a drying unit that dries the ink ejected onto the recording medium. By having a drying means, high-speed image recording is realized.
Heating and drying can be performed by a known heating means such as a heater, an air blowing means such as a dryer, or a combination of these. As the heating method, for example, a method of applying heat with a heater or the like from the side opposite to the treatment liquid application surface of the recording medium, a method of applying warm air or hot air to the treatment liquid application surface of the recording medium, or an infrared heater was used. The heating method etc. are mentioned, You may heat combining these two or more.
In the drying means, the surface temperature of the recording medium is preferably 35 ° C. to 200 ° C., more preferably 40 ° C. to 150 ° C. By setting the temperature in the drying means within the above range, it is preferable that the ink can be dried quickly, while the scorching of the recording medium, the increase in apparatus cost, and the increase in power consumption are suppressed.
The surface temperature of the recording medium is a value measured as follows. First, a radiation thermometer is installed at a location 0.5 m from the drying device of the recording device by the recording medium conveyance distance. Then, the temperature of the non-image recording portion (blank portion) of the recording medium is measured by the radiation thermometer, and the measured temperature is obtained as the surface temperature of the recording medium.

  Further, the image recording apparatus of the present embodiment may use an ink cartridge that contains the ink according to the present embodiment and is made into a cartridge so as to be attached to and detached from the recording apparatus. An ink cartridge set that contains each water-based ink of the ink set according to the present embodiment and is made into a cartridge so as to be attached to and detached from the recording apparatus may be used.

Hereinafter, an example of the image recording apparatus of the present embodiment will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an example of an ink jet recording apparatus according to the present embodiment.
As shown in FIG. 1, the inkjet recording apparatus 10 is a recording apparatus that includes an ejection head 122 (an ejection apparatus 121 having the ejection head 122) that ejects aqueous ink (hereinafter also referred to as “ink”) onto a recording medium P. is there. In the ink jet recording apparatus 10, an ink jet recording apparatus having an ejection unit that ejects ink onto the recording medium P is realized. Thereby, an image by ink is recorded on the recording medium P.

Specifically, the inkjet recording apparatus 10 includes an image recording unit 12 that records an image on a continuous paper (hereinafter, also referred to as “continuous paper P”) as a recording medium P, for example.
The recording apparatus 10 adjusts the pre-processing unit 14 in which the continuous paper P supplied to the image recording unit 12 is accommodated, the conveyance amount of the continuous paper P supplied from the pre-processing unit 14 to the image recording unit 12, and the like. And a buffer unit 16. The buffer unit 16 is disposed between the image recording unit 12 and the preprocessing unit 14.
The recording apparatus 10 includes, for example, a post-processing unit 18 that stores the continuous paper P discharged from the image recording unit 12, and a conveyance amount of the continuous paper P discharged from the image recording unit 12 to the post-processing unit 18. A buffer unit 20 to be adjusted. The buffer unit 20 is disposed between the image recording unit 12 and the post-processing unit 18.
The recording apparatus 10 includes a cooling unit 22 that is disposed between the image recording unit 12 and the buffer unit 20 and cools the continuous paper P that is carried out of the image recording unit 12.

The image recording unit 12 includes, for example, a roll member (not shown) that guides the continuous paper P along the conveyance path 124 of the continuous paper P, and a continuous paper that is conveyed along the conveyance path 124 of the continuous paper P. And an ejection device 121 that ejects ink (ink droplets) onto the paper P to record an image.
The ejection device 121 includes an ejection head 122 that ejects ink onto the continuous paper P. The ejection head 122 has, for example, an effective recording area (arrangement area of nozzles for ejecting ink) equal to or greater than the width of the continuous paper P (the length in a direction intersecting (for example, orthogonal to) the continuous paper P conveyance direction). This is a long recording head.
The ejection head 122 is not limited to this, and is an ejection head that is shorter than the width of the continuous paper P, and is a system that discharges ink by moving in the width direction of the continuous paper P (so-called carriage system). ).

The ejection head 122 may be a so-called thermal system that ejects ink droplets by heat, or may be a so-called piezo system that ejects ink droplets by pressure. Applied.
The ejection head 122 includes, for example, an ejection head 122K that ejects ink onto the continuous paper P and records a K (black) color image, an ejection head 122Y that records a Y (yellow) color image, and an M (magenta). ) A discharge head 122M that records a color image, and a discharge head 122C that records a C (cyan) color image. The ejection head 122K, the ejection head 122Y, the ejection head 122M, and the ejection head 122C are in this order in the transport direction of the continuous paper P (hereinafter, simply referred to as “paper transport direction”). Are arranged so as to face the continuous paper P from the upstream side to the downstream side. In the description of the ejection head, when K, Y, M, and C are not distinguished, the symbols K, Y, M, and C are omitted.

The ejection heads 122K, 122Y, 122M, and 122C are connected to ink cartridges 123K, 123Y, 123M, and 123C of each color that are attached to and detached from the ink jet recording apparatus 10 through supply pipes (not shown). Ink is supplied to each ejection head 122.
The ejection head 122 is not limited to the form in which the four ejection heads 122 corresponding to each of the above four colors are arranged, and according to the purpose, four or more ejections corresponding to each of four or more colors including other intermediate colors. The form which has arrange | positioned the head 122 may be sufficient.
Here, as the discharge head 122, for example, a low-resolution discharge head 122 (for example, a 600 dpi discharge head) that discharges ink in a range of ink droplet amount to 15 pl or less, ink is discharged in a range of ink droplet amount of less than 10 pl. Any of the high-resolution ejection heads 122 (for example, a 1,200 dpi ejection head) may be provided. Further, the ejection device 121 may include both a low resolution ejection head 122 and a high resolution ejection head 122. The ink droplet amount of the ejection head 122 is in the range of the maximum ink droplet amount. In addition, dpi means “dot per inch”.
In the discharge device 121, for example, the back surface of the continuous paper P is wound on the downstream side in the paper conveyance direction with respect to the discharge head 122, and the continuous paper is rotated while being driven in contact with the continuous paper P to be conveyed. A drying drum 126 (an example of a drying device) for drying an image (ink) on P is disposed.
A heating source (for example, a halogen heater or the like: not shown) is built in the drying drum 126. The drying drum 126 dries the image (ink) on the continuous paper P by heating with a heating source.
Around the drying drum 126, a hot air blower 128 (an example of a drying device) that dries an image (ink) on the continuous paper P is disposed. The image (ink) on the continuous paper P wound around the drying drum 126 is dried by the warm air from the warm air blower 128.
Here, the ejection device 121 has a near-infrared heater (not shown) for drying an image (ink) on the continuous paper P, a laser irradiation device, and the like downstream of the ejection head 122 in the paper conveyance direction. The drying device may be arranged. Other drying devices such as a near-infrared heater and a laser irradiation device are arranged instead of at least one of the drying drum 126 and the hot air blowing device 128 or in addition to the drying drum 126 and the hot air blowing device 128.

  On the other hand, the preprocessing unit 14 includes a supply roll 14A around which the continuous paper P supplied to the image recording unit 12 is wound. The supply roll 14A is rotatably supported by a frame member (not shown). ing.

  In the buffer unit 16, for example, a first pass roller 16A, a dancer roller 16B, and a second pass roller 16C are arranged along the paper transport direction. The dancer roller 16 </ b> B moves up and down in FIG. 1 to adjust the tension of the continuous paper P conveyed to the image recording unit 12 and the conveyance amount of the continuous paper P.

  The post-processing unit 18 includes a winding roll 18A as an example of a transport unit that winds the continuous paper P on which images are recorded. The take-up roll 18 </ b> A receives a rotational force from a motor (not shown) and rotates so that the continuous paper P is transported along the transport path 124.

In the buffer unit 20, for example, a first pass roller 20A, a dancer roller 20B, and a second pass roller 20C are arranged along the paper transport direction. The dancer roller 16 </ b> B moves up and down in FIG. 1 to adjust the tension of the continuous paper P discharged to the post-processing unit 18 and the conveyance amount of the continuous paper P.
The cooling unit 22 is provided with a plurality of cooling rollers 22A. The continuous paper P is cooled by conveying the continuous paper P between the plurality of cooling rollers 22A.

Next, the operation (recording apparatus) by the recording apparatus 10 according to the present embodiment will be described.
In the recording apparatus 10 according to the present embodiment, first, the continuous paper P is conveyed from the supply roll 14 </ b> A of the preprocessing unit 14 to the image recording unit 12 through the buffer unit 16.
Next, in the image recording unit 12, ink is ejected from the ejection heads 122 of the ejection device 121 onto the continuous paper P. As a result, an ink image is formed on the continuous paper P. Thereafter, the image (ink) on the continuous paper P is dried from the back side of the continuous paper P (the surface opposite to the recording surface) by the drying drum 126. Then, the ink (image) discharged onto the continuous paper P is dried from the surface side (recording surface) of the continuous paper P by the hot air blower 128. That is, the ink discharged onto the continuous paper P is dried by the drying drum 126 and the hot air blowing device 128.
Next, in the cooling unit 22, the continuous paper P on which the images are recorded is cooled by the cooling roller 22A.
Next, through the buffer unit 16, the post-processing unit 18 winds the continuous paper P on which the images are recorded by the winding roll 18A.

Through the above-described means, an ink image is recorded on the continuous paper P as the recording medium P.
In the inkjet recording apparatus 10, the method of directly ejecting ink droplets onto the surface of the recording medium P by the ejection device 121 (ejection head 122) has been described. However, the present invention is not limited to this. A method of transferring ink droplets on the intermediate transfer member to the recording medium P after discharging the droplets may be used.

  Further, in the inkjet recording apparatus 10, the method of recording an image by ejecting ink onto the continuous paper P as the recording medium P has been described. However, the method of recording the image by ejecting ink onto a sheet as the recording medium P It may be.

  Hereinafter, the present embodiment will be described in detail with reference to examples. However, the present embodiment is not limited only to the following examples. In the following description, “parts” means “parts by weight” unless otherwise specified.

(Preparation of inkjet inks 1 to 7)
The components listed in Table 1 were mixed to prepare inkjet inks 1-7.
In Table 1, the numerical value of each component means part by mass, and the amount of ion-exchanged water was added as the remainder so that the total of each component was 100 parts by mass. In addition, “-” in the table indicates that the corresponding component is not contained.
After mixing the components described in Table 1, inkjet inks 1 to 7 were prepared by filtering with a filter having a pore size of 5 μm (MILLEX-SV, manufactured by Millipore).

The details of each compound in the table are as follows.
・ For colorant yellow (CI Pigment Yellow-17)
-Colorant for magenta (CI Pigment Red 122)
・ For colorant cyan (CI Pigment Blue 15)
・ For colorant black (Mogul L: manufactured by Cabot Corporation)
・ Infrared absorber NIR-AM1 (manufactured by Nagase ChemteX Corporation)
・ Infrared absorber KAYASORB PS-210 (Nippon Kayaku Co., Ltd.)
・ Infrared absorbent inorganic fine particle T-1 (Mitsubishi Materials Electronics Chemical Co., Ltd.)
・ Glycerin (Wako Pure Chemical Industries, Ltd.)
・ Diethylene glycol (Wako Pure Chemical Industries, Ltd.)
・ Surfinol 465 (manufactured by Nissin Chemical Industry Co., Ltd.)
・ Ion exchange water

(Preparation of treatment liquids 1 to 3)
After mixing each component described in Table 2, treatment liquids 1 to 3 were prepared by filtering with a filter having a pore size of 5 μm (MILLEX-SV, manufactured by Millipore).
In Table 2, the numerical value of each component means mass% as solid content, and the amount of ion-exchanged water was added as the remainder so that the total of each component was 100 parts by mass. In addition,-in the table | surface has shown not containing an applicable component.

Among the components used in Table 2, details of components not listed in Table 1 are as follows.
・ Diethylene glycol (Wako Pure Chemical Industries, Ltd.)
・ Propylene glycol (Wako Pure Chemical Industries, Ltd.)
・ Tetraethylene glycol (Wako Pure Chemical Industries, Ltd.)

(Examples 1-4 and Comparative Examples 1-3)
<Storage stability test>
Each ink or treatment liquid listed in Table 3 was weighed into a 50 g sample bottle, stored in a 60 ° C. environmental chamber for 2 weeks with a lid on, and visually checked for the presence or absence of component precipitation and separation / decomposition. confirmed.
Those in which neither sedimentation nor separation / decomposition of components were judged good, and those in which at least one was confirmed were judged bad. The determination results are shown in Table 3.

(Examples 5-8 and Comparative Examples 4-7)
<Image quality evaluation test>
A recording apparatus having a piezo head of 600 dpi (maximum ink droplet amount 11 pl) was used as an ink ejection head, and after the ink 7 treatment liquid shown in Table 1 was ejected, ink 1, ink 2, ink 3, and ink 4, “NPi Form Next-IJ” and character image “Hibi” manufactured by Nippon Paper Industries Co., Ltd. were recorded and irradiated with UH-USC-CL300. Then, the recorded character image was visually observed and evaluated for bleeding (between colors) of the character image to evaluate image quality. The evaluation criteria are as follows. The evaluation results are shown in Table 4.
A: There is no blur of an image.
B: There is a slight blur of the image.
C: Image blurring is remarkable.

10: inkjet recording device 12: image recording unit 14: pre-processing unit 14A: supply roll 16: buffer unit 16A: first pass roller 16B: dancer roller 16C: second pass roller 18: post-processing unit 18A: take-up roll 20: buffer Unit 20A: first pass roller 20B: dancer roller 20C: second pass roller 22: cooling unit 22A: cooling roller 121: discharge devices 122, 122K, 122Y, 122M, 122C: discharge heads 123, 123K, 123Y, 123M, 123C: ink Cartridge 124: Conveyance path 126: Drying drum 128: Hot air blower P: Recording medium

Claims (5)

An ink jet recording ink containing at least a colorant and water;
An inkjet ink set comprising a treatment liquid containing an infrared absorber.   The inkjet ink set according to claim 1, wherein the treatment liquid contains an inorganic material as the infrared absorber.   The inkjet ink set according to claim 1, wherein the treatment liquid contains an organic dye as the infrared absorber.   The ink set includes, as the ink jet recording ink, a cyan ink jet recording ink, a magenta ink jet recording ink, a yellow ink jet recording ink, and a black color ink jet recording ink. Item 4. The inkjet ink set according to any one of Items 1 to 3. Processing liquid discharge means for discharging the processing liquid on the recording medium;
Ink ejection means for ejecting ink for inkjet recording onto the recording medium;
The image recording apparatus using the inkjet ink set according to claim 1, further comprising: an irradiating unit configured to irradiate the treatment liquid attached on the recording medium with infrared rays.

Images