JP2020097141A - Printer and method of manufacturing printed matter - Google Patents

Abstract

To provide a printer capable of reliably obtaining printed matter irradiated with electromagnetic waves.SOLUTION: A printer, which obtains printed matter by applying printing to a body subjected to the printing, includes: a printing part that applies the printing to the body subjected to the printing; an electromagnetic wave irradiation part that applies the electromagnetic waves to the body subjected to the printing; and a detection part that detects a signal, caused by applying the electromagnetic waves to the body subjected to the printing, by an electron spin resonance method.SELECTED DRAWING: None

Description

The present invention relates to a printing apparatus and a method for manufacturing a printed matter.

In the production of printed materials, various printed materials such as packages and food containers are printed to obtain printed materials. For example, Patent Document 1 below discloses a technique of applying a printing ink layer to the outer surface of a package by an offset method.

JP 2002-114934 A

In the production of printed matter, electromagnetic waves may be applied to the material to be printed for sterilization/insecticide/antibacterial treatment. In recent years, from the viewpoint of obtaining a highly safe printed matter by surely performing sterilization, insecticidal treatment, antibacterial treatment, and the like, there has been a demand for a method for surely confirming that the electromagnetic wave is irradiated when the printed matter is obtained.

It is an object of the present invention to provide a printing apparatus and a method for manufacturing a printed matter that can reliably obtain a printed matter that is irradiated with electromagnetic waves.

A printing apparatus according to one aspect of the present invention is a printing apparatus that obtains a printed matter by printing on a printing medium, a printing unit that prints on the printing medium, and an electromagnetic wave that irradiates the printing medium with electromagnetic waves. An irradiation unit and a detection unit that detects a signal caused by irradiation of the electromagnetic wave on the printing medium by an electron spin resonance method are provided.

A method for producing a printed matter according to another aspect of the present invention is a method for producing a printed matter by performing printing on an object to be printed, which comprises a printing step of performing printing on the object to be printed, An electromagnetic wave irradiation step of irradiating an electromagnetic wave, and a step of detecting a signal resulting from the irradiation of the electromagnetic wave on the printing medium by an electron spin resonance method after the printing step and the electromagnetic wave irradiation step.

According to the above-described printing apparatus and method for producing a printed matter, it is possible to reliably confirm that the printed material is irradiated with the electromagnetic wave by detecting the signal caused by the irradiation of the electromagnetic wave on the printed material by the electron spin resonance method. be able to. As a result, since sterilization, insecticide, antibacterial treatment and the like can be carried out with certainty, it is possible to surely obtain a highly safe printed matter irradiated with electromagnetic waves.

ADVANTAGE OF THE INVENTION According to this invention, the printing apparatus and the manufacturing method of a printed matter which can obtain the printed matter irradiated with the electromagnetic wave reliably can be provided.

Hereinafter, embodiments of the present invention will be described in detail. In the present specification, “(meth)acrylic acid” is a generic term for acrylic acid and methacrylic acid corresponding thereto, and the same applies to other similar expressions such as “(meth)acrylate”. ..

A printing apparatus for a printed matter according to the present embodiment is a printing apparatus for printing a printed matter to obtain a printed matter, and a printing section for printing the printed matter and an electromagnetic wave irradiation section for irradiating the printed matter with electromagnetic waves. And a detection unit that detects a signal caused by irradiation of electromagnetic waves on the printing medium by an electron spin resonance method. The method for producing a printed matter according to the present embodiment is a method for producing a printed matter by performing printing on a printing medium to obtain a printed matter, and a printing step for printing the printing medium and an electromagnetic wave for irradiating the printing medium with electromagnetic waves. An irradiation step and a detection step of detecting a signal resulting from the irradiation of the electromagnetic wave on the printing medium by an electron spin resonance method after the printing step and the electromagnetic wave irradiation step.

In the printed matter manufacturing method according to the present embodiment, the printed matter printing apparatus according to the present embodiment can be used. The order of the printing step and the electromagnetic wave irradiation step is not particularly limited, and the printing step may be performed after the electromagnetic wave irradiation step, but the electromagnetic wave irradiation step is preferably performed after the printing step.

According to the present embodiment, it is possible to reliably confirm that the electromagnetic wave is applied to the printing medium by detecting the signal resulting from the irradiation of the electromagnetic wave on the printing medium by the electron spin resonance method. As a result, since sterilization, insecticide, antibacterial treatment and the like can be carried out with certainty, it is possible to surely obtain a highly safe printed matter irradiated with electromagnetic waves. In the present embodiment, for example, a radical is generated from the printing medium by irradiating the printing medium with an electromagnetic wave, and the radical can be detected as a signal by an electron spin resonance method. This embodiment can contribute to ensuring safety in the packaging field such as food packaging, medicine packaging, and medical device packaging.

According to the present embodiment, it is possible to reliably determine that the printing medium is irradiated with the electromagnetic wave based on the data. According to the present embodiment, by using the electron spin resonance method, it is possible to determine in a short time that the printing medium is irradiated with the electromagnetic wave, and it is easy to downsize the printing apparatus.

According to the printing apparatus and the method for manufacturing a printed matter according to the present embodiment, by irradiating the material to be printed with electromagnetic waves, sterilization treatment, insecticidal treatment, antibacterial treatment, crop growth suppression treatment (for example, potato bud prevention), It is possible to perform foreign matter inspection processing and the like. In this case, since it is possible to suppress the use of chemicals and the heating of the printed matter, it is easy to suppress the deterioration of the printed matter. In addition, since these treatments can be performed while the printed matter is packaged, secondary contamination can be prevented.

According to the printing apparatus and the method for manufacturing a printed matter according to the present embodiment, when it is confirmed that foreign matter is mixed inside the printed matter after opening the printed matter, a signal caused by irradiation of electromagnetic waves is measured by an electron spin resonance method. The time when the foreign matter is mixed can be specified by the detection. That is, when the signal is detected from the foreign matter and the printed matter, it can be specified that the foreign matter was mixed before the opening because the foreign matter was present at the time of electromagnetic wave irradiation before opening, and when the signal was not detected from the foreign matter and the printed matter. It is possible to specify that there is a possibility that foreign matter has been mixed in after opening.

The material to be printed is not particularly limited, and examples thereof include a package and a food container. Examples of the articles to be packaged in the package include foods, medicines, various instruments (medical tools, etc.), and the like. Examples of the packaging material for packaging the article to be packaged include a plastic film, paper, cloth, and a laminate (multilayer film, laminate, etc.) containing a plurality of these materials. As a constituent material of the plastic film, polyester such as polyethylene terephthalate and polyethylene naphthalate; polyolefin such as polyethylene and polypropylene; polyamide such as nylon; polystyrene; polyvinyl alcohol; polyvinyl chloride; polycarbonate; polyacrylonitrile; polylactic acid; ethylene vinyl alcohol Resin etc. are mentioned. Cardboard may be used as the packaging material.

The printing unit according to the present embodiment prints on the printing medium. The printing process of the printed material manufacturing method according to the present embodiment can be performed in the printing unit.

Examples of the printing method include inkjet printing, gravure printing, flexo printing, offset printing and the like, and inkjet printing is preferred. The printing unit may print the ink on the printing medium. Examples of the ink include water-based inks (water-based dye inks, water-based pigment inks, etc.) and solvent-based inks. The water-based ink is preferable, and the water-based pigment ink is more preferable. In general, when water-based ink is used, there is a concern that bacteria may be propagated due to water, but in the present embodiment, it is possible to perform sterilization/antibacterial treatment by irradiation with electromagnetic waves, and therefore water-based ink is preferably used. be able to. The ink may be an edible ink.

The printing unit may include a drying unit that dries the ink printed on the printing medium. In the drying section, the ink can be dried by blowing air and/or heating. Examples of the drying unit include NIR (near infrared irradiation device), dryer (warm air dryer), hot plate and the like. The printing apparatus according to the present embodiment may include a drying unit independent of the printing unit. In the printing step in the method for producing a printed matter according to the present embodiment, the ink may be dried after printing the printing medium.

In the printing unit, the ink may be photocured (by irradiating the ink with light) after printing the photocurable ink on the printing medium. Examples of the light for photocuring include ultraviolet rays. The wavelength of light for photocuring may be, for example, 365 to 420 nm. The ink printed on the printing medium may not have curability (for example, photocurability).

The electromagnetic wave irradiation unit irradiates the printing medium with electromagnetic waves. The electromagnetic wave irradiation step of the printed material manufacturing method according to the present embodiment can be performed in the electromagnetic wave irradiation unit. The electromagnetic wave irradiation unit irradiates the printed material with electromagnetic waves to sterilize the printed material (sterilization processing), insecticidal treatment, antibacterial processing (for example, bacterial growth suppression processing), crop growth suppression processing (for example, Potato sprout prevention), foreign material inspection processing, etc. can be performed. The electromagnetic wave may be applied to at least a part of the printing target, and may be applied to the entire printing target.

The electromagnetic, ultraviolet (wavelength: for example 254 nm, dose: for example ^{10~420mJ / cm 2 (350mJ / cm} 2 , etc.)), radiation and the like, ultraviolet ray is preferable.

The wavelength of the ultraviolet light may be 380 nm or less, may be less than 365 nm, may be 350 nm or less, may be 300 nm or less, and may be 270 nm or less. Especially for the purpose of sterilization, 250 nm to 260 nm is preferably used. As a light source for irradiating ultraviolet rays, a light source commercially available as a sterilizing lamp or a sterilizing lamp can be used. For example, a low pressure mercury lamp using an ultraviolet transmitting glass tube can be used.

Examples of the radiation include gamma rays (for example, 25 kGy), X-rays, electron beams (for example, 10 to 30 kGy), and gamma rays emitted from cobalt 60 (Co-60) can be used. The absorbed dose of radiation can be adjusted according to the application. The absorbed dose of radiation may be 0.1 kGy or more, 1 kGy or more, 5 kGy or more, 10 kGy or more, 15 kGy or more, and 20 kGy or more. The absorbed dose of radiation may be 50 kGy or less, 40 kGy or less, 30 kGy or less, 20 kGy or less, 10 kGy or less, or 1 kGy or less. From these viewpoints, the absorbed dose of radiation may be 0.1 to 50 kGy. In the sterilization/insecticide/antibacterial treatment of a material to be printed including a medical device, radiation of 20 to 30 kGy (eg gamma ray) can be applied. In the sterilization, insecticidal and antibacterial treatment of a printing material including food, radiation of 0.1 to 1 kGy can be applied for insecticidal treatment of parasites and pests, and irradiation of 1 to 10 kGy can be applied for sterilization and antibacterial treatment of microorganisms.

The detection unit detects a signal (for example, an absorption signal) resulting from the irradiation of the electromagnetic waves on the printing medium by an electron spin resonance method (ESR method). The detection step of the printed material manufacturing method according to the present embodiment can be performed in the detection unit. The detection unit can detect the radicals generated from the printing medium by irradiating the printing medium with an electromagnetic wave by the electromagnetic wave irradiating unit, using the electron spin resonance method as a signal.

In the printing apparatus, at least two kinds selected from the group consisting of the printing unit, the electromagnetic wave irradiation unit, and the detection unit may be housed (built-in) in the same space (for example, housing), or housed (built-in) in the same space. It does not have to be. For example, the electromagnetic wave irradiation unit and the detection unit may be housed in the same space. The space may be sealed or unsealed.

The printing apparatus according to the present embodiment may include a printing material preparation unit that manufactures a printing material. The article-to-be-printed production unit may be a package-body production unit that wraps an article to be packaged to produce a package. The printing medium preparation section may be housed in the same space (for example, a housing) together with at least one selected from the group consisting of a printing section, an electromagnetic wave irradiation section, and a detection section.

The method for manufacturing a printed material according to the present embodiment may include a printing material manufacturing step of manufacturing a printing material. The printing material preparation step can be performed in the printing material preparation unit. The to-be-printed body manufacturing step may be a package-body manufacturing step in which the object to be packaged is packaged to produce a package. The printing step and the electromagnetic wave irradiating step can be performed after the step of producing the printed material.

The printing apparatus according to the present embodiment may include a base material stacking unit that stacks a base material on a printed object. In the base material laminating section, for example, a base material may be laminated on the ink of the printing medium. Further, in the base material laminating section, the base material may be laminated on the ink and the adhesive after the adhesive is applied to the ink. The base material laminated section may be housed in the same space (for example, a housing) together with at least one selected from the group consisting of a printing section, an electromagnetic wave irradiation section, and a detection section.

The method for manufacturing a printed matter according to the present embodiment may include a base material laminating step of laminating a base material on the printing target after the printing step. The base material laminating step can be performed in the base material laminating section. An electromagnetic wave irradiation step may be performed after the base material laminating step.

The printing apparatus according to the present embodiment may include a carrying unit that carries the printing medium. The transport unit has a transport path for transporting the print target between at least two types selected from the group consisting of the printing unit, the electromagnetic wave irradiation unit, the detection unit, the print target production unit, and the substrate stacking unit. Good. For example, the transport unit may have a series of transport paths T that transport the printing medium from the electromagnetic wave irradiation unit to the detection unit. The conveyance path T may be a conveyance path that conveys the printing medium from the printing unit to the detection unit via the electromagnetic wave irradiation unit, and conveys the printing medium from the electromagnetic wave irradiation unit to the detection unit via the printing unit. It may be a transport path. The transport path T may be a transport path that transports the printing medium from the printing medium manufacturing unit to the detection unit via the printing unit and the electromagnetic wave irradiation unit. In the method for producing a printed material according to the present embodiment, at least one selected from the group consisting of a printing step, an electromagnetic wave irradiation step, a detection step, a printing material preparing step, and a substrate laminating step while conveying the printing material. You can go.

The printing apparatus according to this embodiment may include a control unit that controls the electromagnetic wave irradiation unit and the detection unit. The control unit, for example, conveys the print medium irradiated with the electromagnetic wave in the electromagnetic wave irradiation unit to the detection unit, and then detects the signal resulting from the irradiation of the electromagnetic wave in the print target by the electron spin resonance method in the detection unit. The electromagnetic wave irradiation unit and the detection unit are controlled. In this way, the electromagnetic wave irradiation unit and the detection unit can be interlocked by the control unit, but the electromagnetic wave irradiation unit and the detection unit may not be interlocked. The control unit may further control at least one selected from the group consisting of a printing medium forming unit, a base material laminating unit, a printing unit, and a conveying unit. In the printed matter manufacturing method according to the present embodiment, the electromagnetic wave irradiation step and the detection step may be performed while being controlled by the control unit.

Hereinafter, examples of constituent components of the ink that can be printed on the printing medium will be described. The ink can contain, for example, an aqueous medium (A) and a coloring material (B). The ink may be an aqueous ink containing an aqueous medium. Further, as the constituent components of the ink, a resin component (C), a compound (D) having a urea bond (hereinafter, sometimes referred to as “compound (D)”), an organic solvent (E), a surfactant (F), A compound (G) having a structure capable of reacting with a carbonyl group (hereinafter, sometimes referred to as “compound (G)”), other additives and the like can be used.

The ink may contain the resin component (C) from the viewpoint of easily obtaining a printed material having excellent scratch resistance. The ink may contain the compound (D) from the viewpoint of improving the settability of the printed matter (performance in which the ink on the surface of the base material does not peel off). From these viewpoints, the ink may contain the resin component (C) and the compound (D). In the present embodiment, the coloring material (B), the resin component (C), the compound (D) and the like may be dissolved or dispersed in the aqueous medium (A) which is a solvent.

(Aqueous medium (A))
The ink may contain the aqueous medium (A) as a solvent. Water can be used as the aqueous medium (A). The aqueous medium (A) may be used as a mixed solvent with the organic solvent (E). As water, specifically, deionized water, ultrafiltered water, reverse osmosis water, distilled water, or other pure water or ultrapure water can be used.

The content of the aqueous medium (A) is set to the total amount of the ink from the viewpoint that it is easy to obtain an ink capable of producing a clear printed matter with excellent settability and high ejection stability required when ejecting by an inkjet recording method. On the other hand, 1 to 98 mass% is preferable, and 5 to 95 mass% is more preferable.

(Color material (B))
As the color material (B), known and commonly used pigments, dyes and the like can be used. Among them, the colorant (B) is preferably a pigment from the viewpoint of easily producing a printed matter having excellent weather resistance and the like. As the color material (B), a colorant having a pigment coated with a resin can also be used.

The pigment is not particularly limited, and it is possible to use an inorganic pigment or an organic pigment usually used in an aqueous gravure ink or an aqueous inkjet recording ink. As the inorganic pigment, for example, iron oxide, carbon black produced by a contact method, a furnace method, a thermal method, or the like can be used. As the organic pigment, for example, azo pigment (including azo lake, insoluble azo pigment, condensed azo pigment, chelate azo pigment, etc.), polycyclic pigment (phthalocyanine pigment, perylene pigment, perinone pigment, anthraquinone pigment, quinacridone pigment, dioxazine pigment, Thioindigo pigments, isoindolinone pigments, quinofuraron pigments, etc.), lake pigments (basic dye type chelates, acid dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used. As the pigment, both non-acid-treated pigment and acid-treated pigment can be used.

Among the above pigments, examples of carbon black that can be used in black ink include C.I. I. Pigment Black 7, No. 2300, No. 2200B, No. 900, No. 960, No. 980, No. 33, No. 40, No. 45, No. 45L, No. 52, HCF88, MA7, MA8, MA100 etc.; Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700 etc. made by Colombia; , Monarch900, Monarch1000, Monarch1100, Monarch1300, Monarch1400, etc.; Color Black FW1, the same FW2, the same FW2V, the same FW18, the same FW200, the same S150, the same S160, the same S170, Printex 35, the same U, and U160 made by Degussa. The same 1400U, Special Black 6, the same 5, the same 4, the same 4A, NIPEX150, NIPEX160, NIPEX170, NIPEX180 and the like can be used.

Specific examples of pigments that can be used in the yellow ink include C.I. I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, 185 and the like. Specific examples of pigments usable in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 112, 122, 123, 146, 176, 184, 185, 202, 209, 269, 282 and the like; C. I. Pigment Violet 19 and the like. Specific examples of pigments that can be used in cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15:3, 15:4, 16, 22, 60, 63, 66 and the like.

Specific examples of the pigment that can be used in the white ink include silicas, calcium silicate, alumina, alumina hydrate, titanium oxide, zinc oxide, talc, clay and the like. These may be surface-treated.

The pigment is preferably provided with a means for favorably dispersing it in the aqueous medium (A) in order to stably exist in the ink. Examples of the means include a method of dispersing (i) a pigment together with a resin component (C) (pigment dispersant) in an aqueous medium (A) by a dispersion method described below; (ii) imparting dispersibility to the surface of the pigment A self-dispersion pigment in which a group (hydrophilic functional group and/or salt thereof) is directly or indirectly bound via an alkyl group, an alkyl ether group, an aryl group or the like is dispersed in an aqueous medium (A). And/or a method of dissolving.

As the self-dispersion pigment, for example, a pigment that is subjected to a physical treatment or a chemical treatment to have a dispersibility imparting group or an active species having a dispersibility imparting group bonded (grafted) to the surface of the pigment is used. can do. Self-dispersion pigments include, for example, vacuum plasma treatment, oxidation treatment with hypohalous acid and/or hypohalite; oxidation treatment with ozone; wet oxidation method of oxidizing the pigment surface with an oxidizing agent in water; p-amino acid. By binding benzoic acid to the surface of the pigment, it can be produced by a method of binding a carboxyl group via a phenyl group.

Since the water-based ink containing the self-dispersion pigment does not need to contain the pigment dispersant, there is almost no foaming due to the pigment dispersant, and it is easy to prepare an ink having excellent ejection stability. Further, the water-based ink containing the self-dispersion type pigment is easy to handle, and a large increase in viscosity due to the pigment dispersant can be suppressed, so that it becomes possible to contain a larger amount of the pigment and a printed matter having a high printing density can be obtained. It can be used for manufacturing.

As the self-dispersion pigment, a commercially available product may be used, and examples of such a commercially available product include Microjet CW-1 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), CAB-O-JET200, CAB. -O-JET300 (above, a brand name, the Cabot company make) etc. are mentioned.

The content of the color material (B) is such that streak generation can be easily prevented, and the excellent dispersion stability of the color material (B) can be maintained, and the print density and scratch resistance of the printed matter can be easily improved. From the viewpoint, it is preferably 0.5 to 20% by mass, more preferably more than 0.5% by mass and 20% by mass or less, further preferably 1 to 20% by mass, and 1.5 to 15% by mass with respect to the total amount of the ink. % Is particularly preferred, 2-10% by mass is very preferred, 2-8% by mass is highly preferred and 2.5-8% by mass is even more preferred.

(Resin component (C))
The ink may contain the resin component (C). The resin component (C) may be used as a pigment dispersant when a pigment is used as the coloring material (B). The pigment dispersant can impart water dispersibility to the pigment particles by adsorbing the pigment dispersant on the surface of the pigment particles having no water dispersibility. The resin component (C) may be used as a binder resin. The binder resin exists independently of the pigment and can contribute to increasing the strength of the printed image (improving scratch resistance).

Examples of the resin component (C) include polyvinyl alcohols; polyvinylpyrrolidones; acrylic resins such as acrylic acid-acrylic acid ester copolymers; styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene. -Styrene-acrylic resin such as methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer; styrene- Aqueous resins such as maleic acid copolymers, styrene-maleic anhydride copolymers, vinylnaphthalene-acrylic acid copolymers; salts of the above aqueous resins; polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone, polyolefins, urethane resins , Dextran, dextrin, color giannan (κ, ι, λ, etc.), agar, pullulan, water-soluble polyvinyl butyral, hydroxyethyl cellulose, carboxymethyl cellulose and the like can be used. Among them, as the resin component (C), it is preferable to use at least one selected from the group consisting of acrylic resins and styrene-acrylic resins. As the resin component (C), Ajinomoto Fine-Techno Co., Ltd.'s Azisper PB series, Big Chemie Japan's Disperbyk series, BASF's EFKA series, JONCRYL series, Nippon Lubrizol's SOLSPERSE series, Evonik The TEGO series manufactured by the company can be used.

As the resin component (C), the following polymer (C1) is preferable from the viewpoint that coarse particles can be significantly reduced and, as a result, good ejection stability required when ejecting an ink by an inkjet recording method can be easily provided.

As the polymer (C1), those having an anionic group can be used. Among them, the solubility in water is 0.1 g/100 mL or less, and when the neutralization rate of the anionic group by the basic compound is 100%, the number average molecular weight capable of forming fine particles in water is 1000 to 6000. It is preferred to use the polymers of

The solubility of the polymer (C1) in water can be defined as follows. That is, first, 0.5 g of a polymer (C1) whose particle size was adjusted to a range of 250 μm to 90 μm using a sieve having openings of 250 μm and 90 μm was sealed in a bag processed with a 400 mesh wire mesh, and immersed in 50 mL of water, The mixture is left under gentle stirring for 24 hours at a temperature of 25°C. After soaking for 24 hours, a 400-mesh wire net enclosing the polymer (C1) is dried for 2 hours by a dryer set at 110°C. The change in mass of a 400-mesh wire mesh enclosing the polymer (C1) before and after immersion in water is measured, and the solubility is calculated by the following formula.
Solubility [g/100 mL]=(polymer-encapsulated 400 mesh wire mesh [g] before immersion-polymer encapsulated 400 mesh wire mesh [g] after immersion)×2

Whether or not the fine particles are formed in water when the neutralization rate of the anionic group by the basic compound is 100% can be determined as follows.
(1) The acid value of the polymer (C1) is previously measured by an acid value measuring method based on JIS test method K0070-1992. Specifically, the acid value is determined by dissolving 0.5 g of the polymer (C1) in tetrahydrofuran and titrating with 0.1M potassium hydroxide alcohol solution using phenolphthalein as an indicator.
(2) After adding 1 g of the polymer (C1) to 50 mL of water, a 0.1 mol/L potassium hydroxide aqueous solution is added to just neutralize the obtained acid value by 100% to make 100% neutralization.
(3) Irradiate the 100% neutralized solution with ultrasonic waves at a temperature of 25° C. for 2 hours in an ultrasonic cleaner (manufactured by SND, ultrasonic cleaner US-102, 38 kHz self-oscillation). After that, leave at room temperature for 24 hours.

After standing for 24 hours, a liquid at a depth of 2 cm from the liquid surface was used as a sample liquid, and a dynamic light scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., dynamic light scattering type particle size measuring device “Microtrac particle size distribution”) was used. UPA-ST150″) is used to determine whether or not the light scattering information due to the formation of the fine particles can be obtained, thereby confirming the presence of the fine particles.

From the viewpoint of further improving the stability of the fine particles formed by the polymer (C1) in water, the particle diameter of the fine particles is preferably 5 to 1000 nm, more preferably 7 to 700 nm, and further preferably 10 to 500 nm. Further, the smaller the particle size distribution of the fine particles, the more excellent the dispersion stability tends to be. However, even when the particle size distribution is wide, it is possible to obtain the ink having the dispersion stability superior to the conventional one. The particle size and the particle size distribution are the same as in the method for measuring the fine particles, the dynamic light scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., the dynamic light scattering type particle size measuring device “Microtrac particle size distribution meter”). UPA-ST150").

The neutralization rate of the polymer (C1) can be determined by the following formula.
Neutralization rate (%)={(mass of basic compound [g]×56×1000)/(acid value [mgKOH/g] of polymer (C1)×equivalent amount of basic compound×mass of polymer (C1)[ g])}×100

The acid value of the polymer (C1) can be measured based on JIS test method K0070-1992. Specifically, it can be determined by dissolving 0.5 g of the sample in tetrahydrofuran and titrating with 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

The number average molecular weight of the polymer (C1) can effectively suppress aggregation of the coloring material (B) such as a pigment in the aqueous medium (A), and the ink having good dispersion stability of the coloring material (B). From the viewpoint of easy obtaining, 1000 to 6000 are preferred, 1300 to 5000 are more preferred, and 1500 to 4500 are even more preferred. The number average molecular weight is a polystyrene-equivalent value measured by GPC (gel permeation chromatography), and is specifically a value measured under the following conditions.

[Method of measuring number average molecular weight (Mn)]
The measurement was carried out by the gel permeation chromatography (GPC) method under the following conditions.
Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation are used in series.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSK gel G4000" (7.8 mm ID x 30 cm) x 1 "TSK gel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: Create a calibration curve using the following standard polystyrene.
{Standard polystyrene}
Tosoh Corporation "TSKgel Standard Polystyrene A-500"
Tosoh Corporation "TSK gel standard polystyrene A-1000"
Tosoh Corporation "TSK gel standard polystyrene A-2500"
Tosoh Corporation "TSK gel standard polystyrene A-5000"
"TSK gel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSK gel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSK gel standard polystyrene F-4" manufactured by Tosoh Corporation
Tosoh Corporation "TSKgel Standard Polystyrene F-10"
Tosoh Corporation "TSK gel standard polystyrene F-20"
Tosoh Corporation "TSK gel standard polystyrene F-40"
Tosoh Corporation "TSK gel standard polystyrene F-80"
Tosoh Corporation "TSK gel standard polystyrene F-128"
Tosoh Corporation "TSK gel standard polystyrene F-288"
Tosoh Corporation "TSK gel standard polystyrene F-550"

As the polymer (C1), a polymer that is insoluble or sparingly soluble in water in an unneutralized state and forms fine particles in a 100% neutralized state can be used. A polymer having a hydrophobic group in a molecule in addition to a certain anionic group can be used.

Examples of such a polymer include a block polymer having a polymer block having a hydrophobic group and a polymer block having an anionic group. In the polymer (C1), the number of the anionic groups and the solubility in water are not necessarily specified by the acid value or the number of the anionic groups at the time of designing the polymer, and have, for example, the same acid value. Even for polymers, those having a low molecular weight tend to have high solubility in water, and those having a high molecular weight tend to have low solubility in water. From this, the polymer (C1) is specified by its solubility in water.

The polymer (C1) may be a homopolymer, but is preferably a copolymer, and may be a random polymer, a block polymer or an alternating polymer, and among them, a block polymer. Is preferred. The polymer (C1) may be a branched polymer, but is preferably a linear polymer.

The polymer (C1) is preferably a vinyl polymer in terms of design flexibility, and as a method for producing a vinyl polymer having desired molecular weight and solubility characteristics, living radical polymerization, living cationic polymerization, and living anionic polymerization can be used. It is preferably produced by using “living polymerization”.

Among them, the polymer (C1) is preferably a vinyl polymer produced by using a (meth)acrylate monomer as one of the raw materials, and as a production method of such a vinyl polymer, living radical polymerization or living anion polymerization is used. Living anionic polymerization is preferable from the viewpoint that the molecular weight of the block polymer and each segment can be designed more precisely.

As the polymer (C1) produced by living anion polymerization, specifically, a polymer represented by the following general formula (c1) can be used.

In general formula (c1), A ¹ represents an organolithium initiator residue, A ² represents a polymer block having a hydrophobic group, A ³ represents a polymer block having an anionic group, and n represents , 1 to 5, and B represents an aromatic group or an alkyl group.

In general formula (c1), A ¹ represents an organolithium initiator residue. Specific examples of the organic lithium initiator (polymerization initiator) include methyl lithium, ethyl lithium, propyl lithium, butyl lithium (n-butyl lithium, sec-butyl lithium, iso-butyl lithium, tert-butyl lithium, etc.), pentyl. Alkyl lithium such as lithium, hexyl lithium, methoxymethyl lithium and ethoxymethyl lithium; benzyl lithium, α-methylstyryl lithium, 1,1-diphenyl-3-methylpentyl lithium, 1,1-diphenylhexyl lithium, phenylethyl Phenylalkylene lithium such as lithium; alkenyl lithium such as vinyl lithium, allyl lithium, propenyl lithium, butenyl lithium; alkynyl lithium such as ethynyl lithium, butynyl lithium, pentynyl lithium, hexynyl lithium; phenyl lithium, naphthyl lithium, etc. Aryl lithium; heterocyclic lithium such as 2-thienyl lithium, 4-pyridyl lithium, and 2-quinolyl lithium; alkyl lithium magnesium complex such as tri(n-butyl)magnesium lithium and trimethylmagnesium lithium.

In the organolithium initiator, the bond between the organic group and lithium is cleaved to generate an active terminal on the organic group side, and polymerization is initiated from there. Therefore, the organic group derived from organolithium is bonded to the end of the obtained polymer. In the present specification, the organic group derived from organolithium bonded to the polymer end is referred to as “organolithium initiator residue”. For example, if the polymer uses methyllithium as the initiator, the organolithium initiator residue will be a methyl group, and if the polymer uses butyllithium as the initiator, the organolithium initiator residue will be a butyl group. ..

In general formula (c1), A ² represents a polymer block having a hydrophobic group. As described above, A ² is preferably a group that is highly adsorbed to the pigment when it comes into contact with the pigment in addition to the purpose of balancing the appropriate solubility as described above. From the same viewpoint, A ² is an aromatic ring or It is preferably a polymer block having a structural unit derived from a monomer having a heterocycle. The polymer block having a structural unit derived from a monomer having an aromatic ring or a heterocycle is specifically a monomer having an aromatic ring such as a styrene-based monomer or a monomer having a heterocycle such as a vinylpyridine-based monomer. Is a polymer block of a homopolymer or a copolymer obtained by homopolymerization or copolymerization of.

Examples of the monomer having an aromatic ring include styrene, p-tert-butyldimethylsiloxystyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, p-tert-butoxystyrene, m-tert-butoxystyrene, Styrene-based monomers such as p-tert-(1-ethoxymethyl)styrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, α-methylstyrene, p-methyl-α-methylstyrene, vinylnaphthalene, Examples thereof include vinyl anthracene. Examples of the monomer having a heterocycle include vinylpyridine-based monomers such as 2-vinylpyridine and 4-vinylpyridine. Each of the monomers having an aromatic ring or a heterocycle can be used alone or in combination of two or more.

In general formula (c1), A ³ represents a polymer block having an anionic group. As described above, A ³ has the purpose of imparting appropriate solubility and the purpose of imparting dispersion stability in water when it becomes a pigment dispersion.

Examples of the anionic group in the polymer block A ³ include a carboxyl group, a sulfonic acid group, a phosphoric acid group and the like. Of these, a carboxyl group is preferred from the viewpoints of ease of preparation, abundance of monomer varieties, availability, and the like. In addition, two carboxyl groups may be an acid anhydride group which is dehydration-condensed within or between molecules.

The method for introducing the anionic group of A ³ is not particularly limited. For example, when the anionic group is a carboxyl group, a homopolymer or a copolymer obtained by homopolymerizing (meth)acrylic acid or copolymerizing with another monomer. The polymer block (PB1) may be a homopolymer obtained by deprotecting a (meth)acrylate having a renewable protective group in the anionic group, which is homopolymerized or copolymerized with another monomer. Alternatively, it may be a polymer block (PB2) in which a part or all of the protective groups that can be regenerated to the anionic group of the copolymer are regenerated to anionic groups.

The use of a polymer block A ³ (meth) acrylic acid or (meth) acrylate, specifically, (meth) acrylic acid, (meth) acrylate, (meth) acrylate, (meth) acrylic acid iso-propyl, allyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, (meth) N-Amyl acrylate, iso-amyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate , N-tridecyl (meth)acrylate, n-stearyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-tert-butyl (meth)acrylate Cyclohexyl, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, adamantyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydro (meth)acrylate Furfuryl, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, ( Tetrafluoropropyl (meth)acrylate, pentafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, pentadecafluorooctyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, N,N- Dimethyl (meth)acrylamide, (meth)acryloylmorpholine, (meth)acrylonitrile, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol-polypropylene glycol (meth)acrylate, polyethylene glycol-polybutylene glycol (meth) Acrylate, polypropylene glycol-polybutylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, ethoxy polyethylene glycol (meth)acrylate, butoxy polyethylene glycol (meth)acrylate, octoxy polyethylene glycol (meth)acrylate Polyphenols such as glutamine, lauroxy polyethylene glycol (meth)acrylate, stearoxy polyethylene glycol (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, methoxy polypropylene glycol (meth)acrylate and octoxy polyethylene glycol-polypropylene glycol (meth)acrylate. Examples thereof include alkylene oxide group-containing (meth)acrylate. These monomers can be used alone or in combination of two or more.

In the living anionic polymerization method, when the monomer to be used is a monomer having a group having an active proton such as an anionic group, the active end of the living anion-polymerized polymer immediately reacts with the group having an active proton and is deactivated. , It is difficult to obtain a polymer. In living anionic polymerization, it is difficult to polymerize a monomer having a group having an active proton as it is. Therefore, polymerization is performed in a state in which the group having an active proton is protected, and then the protective group is deprotected to remove the active proton. It is preferable to regenerate the groups that it has.

For this reason, in the polymer block A ^3, it is preferable to use a monomer containing a (meth) acrylate having an anionic renewable protecting group group by deprotection. By using the monomer, the above-mentioned inhibition of the polymerization can be prevented during the polymerization. Further, the anionic group protected by the protective group can be regenerated into an anionic group by deprotecting the block polymer after obtaining it.

For example, when the anionic group is a carboxyl group, the carboxyl group can be regenerated by esterifying the carboxyl group and deprotecting it by hydrolysis or the like in a subsequent step. In this case, the protective group that can be converted into a carboxyl group is preferably a group having an ester bond, and examples thereof include primary alkoxycarbonyl such as methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, and n-butoxycarbonyl group. Group; secondary alkoxycarbonyl group such as isopropoxycarbonyl group and sec-butoxycarbonyl group; tertiary alkoxycarbonyl group such as t-butoxycarbonyl group; phenylalkoxycarbonyl group such as benzyloxycarbonyl group; ethoxyethylcarbonyl group And other alkoxyalkylcarbonyl groups and the like.

When the anionic group is a carboxyl group, usable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec. -Butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate ) Acrylate), tridecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), nonadecyl (meth)acrylate, icosanyl (meth) ) Alkyl (meth)acrylates such as acrylates; phenylalkylene (meth)acrylates such as benzyl (meth)acrylate; alkoxyalkyl (meth)acrylates such as ethoxyethyl (meth)acrylate. These (meth)acrylates may be used alone or in combination of two or more. Further, among these (meth)acrylates, one or more selected from the group consisting of t-butyl (meth)acrylate and benzyl (meth)acrylate is preferable from the viewpoint of easy conversion reaction to a carboxyl group, and industrial use. From the viewpoint of easy availability, t-butyl (meth)acrylate is more preferable.

In general formula (c1), B represents an aromatic group or an alkyl group. As the alkyl group, an alkyl group having 1 to 10 carbon atoms can be used. Moreover, n represents the integer of 1-5.

In the living anionic polymerization method, when an attempt is made to directly polymerize a (meth)acrylate monomer on the active terminal of a styrene-based polymer having strong nucleophilicity, there are cases where carbonyl carbon cannot be polymerized due to nucleophilic attack. Therefore, when the (meth)acrylate monomer is polymerized to A ¹ -A ² , a (meth)acrylate monomer can be polymerized after using a reaction modifier to adjust the nucleophilicity. B in the general formula (c1) is a group derived from a reaction modifier. Specific examples of the reaction modifier include diphenylethylene, α-methylstyrene, p-methyl-α-methylstyrene and the like.

The living anion polymerization method can be carried out by adjusting the reaction conditions by a batch method as used in conventional free radical polymerization, or may be a method of continuously polymerizing by a microreactor. Since the microreactor has a good mixing property of the polymerization initiator and the monomer, the reactions start simultaneously, the temperature is uniform, and the polymerization rate can be made uniform, so that the molecular weight distribution of the produced polymer can be narrowed. At the same time, since the growth end is stable, it becomes easy to produce a block copolymer in which both components of the block do not mix. Further, since the controllability of the reaction temperature is good, it is easy to suppress side reactions.

Then, the block copolymer is produced by quenching the reaction with a compound having an active proton (methanol or the like).

When the polymer (C1) represented by the general formula (c1) is produced in the microreactor, a monomer having a hydrophobic group (for example, a monomer having an aromatic ring or a heterocycle) is used as the first monomer. Then, by reacting using an organolithium initiator as a polymerization initiator, a polymer block having a hydrophobic group of A ² (for example, a polymer block having a structural unit derived from a monomer having an aromatic ring or a heterocycle) (The organic group that is the organolithium initiator residue of A ¹ is bonded to one end of the polymer block A ² ).

Next, after adjusting the reactivity of the growth terminal using a reaction modifier, a monomer containing a (meth)acrylate having a reproducible protecting group for the anionic group is reacted as the second monomer to produce a polymer. Get the block.

Then, the above A ³ (that is, a polymer block containing an anionic group) is obtained by regenerating the anionic group by a deprotection reaction such as hydrolysis.

The method for regenerating the anionic group to the anionic group by deprotection reaction such as hydrolysis of the ester bond of the protective group which is reproducible will be described in detail below.

The hydrolysis reaction of the ester bond proceeds under both acidic and basic conditions, but the conditions are slightly different depending on the group having an ester bond. For example, when the group having an ester bond is a primary alkoxycarbonyl group such as a methoxycarbonyl group or a secondary alkoxycarbonyl group such as an isopropoxycarbonyl group, hydrolysis can be performed under basic conditions. A carboxyl group can be obtained. At this time, examples of the basic compound under the basic condition include metal hydroxides such as sodium hydroxide and potassium hydroxide.

When the group having an ester bond is a tertiary alkoxycarbonyl group such as t-butoxycarbonyl group, a carboxyl group can be obtained by performing hydrolysis under acidic conditions. At this time, examples of the acidic compound under acidic conditions include mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid; brested acids such as trifluoroacetic acid; Lewis acids such as trimethylsilyl triflate. The reaction conditions for the hydrolysis of the t-butoxycarbonyl group under acidic conditions are disclosed, for example, in “Chemical Society of Japan, 5th Edition, Experimental Chemistry Lecture 16 Synthesis IV of Organic Compounds”.

As a method for converting the t-butoxycarbonyl group into a carboxyl group, for example, a method using a cation exchange resin in place of the above acid can also be mentioned. Examples of the cation exchange resin include resins having an acid group such as a carboxyl group (—COOH) and a sulfo group (—SO ₃ H) in the side chain of the polymer chain. Among these, a cation exchange resin having a sulfo group in the side chain of the resin and exhibiting strong acidity is preferable because the reaction can be accelerated. Examples of commercially available cation exchange resins include strongly acidic cation exchange resin "Amberlite" manufactured by Organo Corporation. From the viewpoint of effective hydrolysis, the amount of the cation exchange resin used is preferably 5 to 200 parts by mass, more preferably 10 to 100 parts by mass, relative to 100 parts by mass of the polymer represented by the general formula (c1). preferable.

When the group having an ester bond is a phenylalkoxycarbonyl group such as a benzyloxycarbonyl group, it can be converted into a carboxyl group by performing a hydrogenation reduction reaction. At this time, as a reaction condition, a phenylalkoxycarbonyl group can be quantitatively regenerated into a carboxyl group by reacting at room temperature in the presence of a palladium catalyst such as palladium acetate using hydrogen gas as a reducing agent.

As described above, since the reaction conditions at the time of conversion into a carboxyl group differ depending on the type of group having an ester bond, for example, t-butyl (meth)acrylate and n-butyl (meth)acrylate are used as A ³ raw materials. The polymer obtained by copolymerization with the above-mentioned compound has a t-butoxycarbonyl group and an n-butoxycarbonyl group. Here, under acidic conditions in which the t-butoxycarbonyl group is hydrolyzed, the n-butoxycarbonyl group does not hydrolyze, so only the t-butoxycarbonyl group can be selectively hydrolyzed and deprotected to a carboxyl group. Becomes Thus, a raw material monomer of A ^3, it is possible to the acid value of the adjustment of the hydrophilic block (A ³⁾ by appropriately selecting a monomer containing a (meth) acrylate having a renewable protecting group an anionic group.

From the viewpoint of improving the stability of the aqueous pigment dispersion in which the pigment is dispersed in water by the polymer (C1), in the polymer (C1) represented by the general formula (c1), the polymer block (A ² ) and the polymer block ( It is advantageous not to be a random copolymer in which A ³ ) is randomly arranged and bonded, but to be a block copolymer in which the polymer blocks are regularly bonded in a unit of a certain length. The aqueous pigment dispersion is a raw material used in the production of ink, and is a liquid in which a pigment is dispersed in water at a high concentration using a polymer (C1). The molar ratio A ² :A ³ of the polymer block (A ² ) and the polymer block (A ³ ) is, for example, from the viewpoint of easily maintaining good ejection stability required when ejecting ink by an inkjet recording method, and coloring. From the viewpoint of easily obtaining an ink capable of producing a printed matter having more excellent properties, 100:10 to 100:500 is preferable, and 100:10 to 100:450 is more preferable.

In the polymer (C1) represented by the general formula (c1), the number of monomers having an aromatic ring or a heterocycle which gives the polymer block (A ² ) is preferably 5 to 40, more preferably 6 to 30, and 7 to 25 is more preferable. The number of anionic groups constituting the polymer block ^{(A 3)} is preferably from 3 to 20, more preferably from 4 to 17, more preferably 5 to 15.

Polymer block ^{(A 2)} and the molar ratio ^A 2 polymer blocks ^{(A 3): A 3} is configured with the number of moles of aromatic ring or heterocyclic ring constituting the polymer block ^{(A 2),} polymer block ^{(A 3)} When expressed as a molar ratio with the number of moles of the anionic group,

The acid value of the polymer (C1) represented by the general formula (c1) is, for example, from the viewpoint of easily maintaining good ejection stability required when ejecting ink by an inkjet recording method, and points such as scratch resistance. From the viewpoint of easily obtaining an ink capable of producing a further excellent printed matter, 40 to 400 mgKOH/g is preferable, 40 to 300 mgKOH/g is more preferable, and 40 to 190 mgKOH/g is further preferable. The acid value of the polymer (C1) was the acid value measured by the same acid value measuring method as the measuring method of the fine particles of the polymer (C1).

The anionic group of the polymer (C1) is preferably neutralized. As the basic compound for neutralizing the anionic group of the polymer (C1), any of known and commonly used basic compounds can be used, and examples thereof include inorganic basic substances such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. Alternatively, organic basic compounds such as ammonia, triethylamine and alkanolamine can be used.

The neutralization amount of the polymer (C1) present in the aqueous pigment dispersion need not be 100% neutralized with respect to the acid value of the polymer. Specifically, the neutralization rate of the polymer (C1) is preferably 20 to 200%, more preferably 80 to 150%.

The resin component (C) preferably has a carbonyl group from the viewpoint of easily obtaining excellent setting properties and adhesiveness. The carbonyl group may be contained in an aldehyde group, a ketone group, an amide group, a carboxyl group and the like. Examples of the resin component (C) include an acrylic resin having an aldehyde group, an acrylic resin having a ketone group, an acrylic resin having an amide group, an acrylic resin having a carboxyl group, and the like. An acrylic resin having an amide group. Resins are preferred.

Binder resin having a carbonyl group can be obtained by polymerizing a monomer component containing a monomer having a carbonyl group, a monomer having a carbonyl group, and other monomers, It may be obtained by polymerizing a monomer component containing Examples of the method for polymerizing the monomer include a solution polymerization method and an emulsion polymerization method.

As the acrylic resin having an amide group, a polymer of an acrylic monomer having an amide group and another monomer used as necessary can be used.

Examples of the acrylic monomer having an amide group include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-methylol(meth)acrylamide. , N-isopropyl(meth)acrylamide, N-butyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N -Dimethylaminopropyl (meth)acrylamide, diacetone (meth)acrylamide, hydroxyethyl (meth)acrylamide, acrylic amide, N,N-dimethyl (meth)acrylic amide, etc. can be used.

Examples of other monomers that can be used for producing the acrylic resin include (meth)acrylic acid and alkali metal salts thereof; methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2 -(Meth)acrylic acid ester-based monomers such as ethylhexyl (meth)acrylate, benzyl (meth)acrylate, and cyclohexyl (meth)acrylate; (meth)acrylonitrile, 2-dimethylaminoethyl (meth)acrylate, glycidyl ( Acrylic monomers such as (meth)acrylate; aromatic vinyl compounds (styrene, α-methylstyrene, p-tert-butylstyrene, vinylnaphthalene, vinylanthracene, etc.), vinylsulfonic acid compounds (vinylsulfonic acid, styrenesulfonic acid) Etc.), vinylpyridine compounds (2-vinylpyridine, 4-vinylpyridine, naphthylvinylpyridine, etc.), vinyltriethoxysilane, vinyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3 -Methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 2-acetoacetoxyethylmethacrylate and the like can be used.

As the other monomer, a monomer having an aromatic group such as styrene and benzyl (meth)acrylate is preferable from the viewpoint of further improving the affinity with the pigment.

The acrylic resin having an amide group imparts an effect of improving redispersibility to the ink and is excellent in dispersion stability in the aqueous medium (A). In the acrylic resin having an amide group, the amount of the acrylic monomer having an amide group used is such that the redispersibility of the ink and the dispersion stability of the ink component in the aqueous medium (A) are further improved. From the above, 0.5 to 5 mass% is preferable, 0.5 to 4 mass% is more preferable, and 1.5 to 3 mass% is further preferable, with respect to the total amount of the monomers used in the production of the acrylic resin. ..

The acrylic resin may contain a component that is insoluble in tetrahydrofuran (THF) which is a developing solvent when measuring the molecular weight by gel permeation chromatography and is difficult to measure the molecular weight, but is included in the ink. The content of the THF-insoluble component at 25°C is 20% by mass from the viewpoint of further improving the adhesion of the ink to plastics and metals that are difficult to absorb water and other solvents, or highly hydrophobic coated paper and art paper. %, less than 5% by mass is more preferable, and one containing no THF insoluble component is further preferable.

The number average molecular weight of the acrylic resin (for example, an acrylic resin soluble in THF) is preferably 10,000 to 100,000, more preferably 20,000 to 100,000. The weight average molecular weight of the acrylic resin is preferably 30,000 to 1,000,000, more preferably 50,000 to 1,000,000.

As the polyolefin, a homopolymer or copolymer of a monomer containing an olefin-based monomer as a main component can be used. As the olefin-based monomer, for example, α-olefin such as ethylene, propylene, butene, hexene, methylbutene, methylpentene and methylhexene; cyclic olefin such as norbornene can be used.

Oxidized polyolefin can also be used as the polyolefin. As the oxidized polyolefin, for example, a polyolefin in which an oxygen atom is introduced into the molecule by thermal decomposition, chemical decomposition using an acid, an alkali component or the like can be used. The oxygen atom constitutes, for example, a carboxyl group having polarity.

90-200 degreeC is preferable and, as for the melting|fusing point of polyolefin, 120 degreeC or more and less than 160 degreeC are more preferable. In these cases, it is possible to impart good settability in which the ink on the surface of the base material does not peel off and excellent scratch resistance even when printed materials are superposed immediately after printing. The melting point of the polyolefin refers to a value measured by a melting point measuring device according to JIS K0064.

As described above, the polyolefin is preferably present in a state of being dissolved or dispersed in the solvent such as the aqueous medium (A), and more preferably in the state of emulsion dispersed in the solvent such as the aqueous medium (A).

In that case, the average particle size of the polyolefin particles formed of the polyolefin is, for example, 10 from the viewpoint of easily achieving good ejection stability of the ink and good settability after printing when printing by an inkjet recording method. -200 nm is preferable and 30-150 nm is more preferable. The average particle size of the polyolefin (A) is a value measured by a dynamic light scattering method using a Microtrac UPA particle size distribution meter manufactured by Nikkiso Co., Ltd.

As the resin component (C), a so-called core-shell type polymer can be used, and a polymer having a carbonyl group in either or both of the core portion and the shell portion can be used. The resin component (C) is a carbonyl group such as an amide group from the viewpoint of easily obtaining excellent adhesion to a substrate having poor adhesion and excellent discharge stability required at the time of discharging by an inkjet method. A core-shell type polymer having a core is preferred. As the core-shell type polymer, from the viewpoint of easily obtaining a more excellent discharge stability at a level required when discharging by an inkjet method, a core part containing an acrylic resin as a monomer component containing diacetone acrylamide, and an optional It is preferable to use a core-shell type acrylic resin having a shell part containing the acrylic resin.

The glass transition temperature of the resin component (C) is −12 to 12 from the viewpoint that it is easy to obtain excellent adhesion to a substrate having poor adhesion and excellent discharge stability required at the time of discharging by the inkjet method. 25°C is preferred. The glass transition temperature of the resin component (C) can be obtained as a theoretical calculated value obtained by the following FOX equation, using the glass transition temperature of each homopolymer of the monomers constituting the resin component (C). As the glass transition temperature of the homopolymer used for the calculation, the value recorded in “POLYMER HANDBOOK THIRD EDITION” (A WILEY-INTERSCIENCE PUBLICATION) can be used.
1/Tg=W1/Tg1+W2/Tg2+...+Wn/Tgn
[In the formula, Tg is the glass transition temperature (unit: K) of the vinyl polymer, W1, W2,..., Wn is the weight fraction of each monomer, and Tg1, Tg2,. Tgn is the glass transition temperature of the homopolymer of each monomer. ]

The resin component (C) is good in that it is easy to obtain excellent adhesion to a substrate having poor adhesion, it is easy to prevent the generation of streaks, and the print density and scratch resistance of printed matter are improved. From the viewpoint of imparting glossiness, 1 to 10 mass% is preferable, 2 to 9 mass% is more preferable, 2 to 9 mass% is still more preferable, and 2 to 9 mass% is particularly preferable, with respect to the total amount of the ink. Highly preferred is 3 to 9 mass %. In addition, in the ink containing the resin component (C) within these ranges, the resin component (C) is cross-linked through a heating step after printing to form a strong coating, thereby further improving the scratch resistance of the printed matter. Can be made. Further, even when water is dropped on the printed matter or when the printed matter is rubbed with a cloth containing water, the ink on the surface of the substrate is not peeled off, and good water resistance can be imparted.

In this embodiment, the resin component (C) and the compound (D) can be used in combination. By using the resin component (C) and the compound (D) in combination, good settability of printed matter and excellent scratch resistance can be imparted.

(Compound (D) having a urea bond)
As the compound (D) having a urea bond, one or more selected from the group consisting of urea and urea derivatives can be used. Since urea and urea derivatives have a high moisturizing function and function as a wetting agent, they prevent the ink from drying or coagulating at the ink ejection port of the inkjet head, and it is easy to ensure excellent ejection stability, resulting in streaking of printed matter. There is an effect that is easy to reduce. In addition, when urea or a urea derivative is used, when urea or a urea derivative is used, non-absorbent or non-absorptive materials are likely to be released from the viewpoint of obtaining a printed matter having more excellent settability because water is easily released when heated. It is preferable to perform heat drying after printing the ink on the recording medium.

Examples of the urea derivative include ethylene urea, propylene urea, diethyl urea, thiourea, N,N-dimethyl urea, hydroxyethyl urea (for example, 2-hydroxyethyl urea), hydroxybutyl urea, ethylene thiourea, diethyl thiourea, and the like. These may be used alone or in combination of two or more. Among them, the compound (D) is preferably one or more selected from the group consisting of urea, ethyleneurea and 2-hydroxyethylurea from the viewpoint of obtaining a printed material having more excellent settability.

The content of the compound (D) is 1 to 20% by mass with respect to the total amount of the ink, from the viewpoint that ejection stability required when ejecting the ink by an inkjet recording method and a printed matter having excellent setting properties are easily obtained. Is preferred, 2 to 15 mass% is more preferred, and 3 to 10 mass% is even more preferred.

When the ink contains the resin component (C) and the compound (D), the mass ratio of the resin component (C) to the compound (D) [resin component (C)/compound (D)] is an effect of improving the settability of the printed matter. From the viewpoint of easy obtaining, 1/6 to 6/1 are preferable, 1/6 to 3/1 are more preferable, and 1/5 to 1/1 are still more preferable.

(Organic solvent (E))
As the organic solvent (E), ketones such as acetone, methyl ethyl ketone, methyl butyl ketone and methyl isobutyl ketone; methanol, ethanol, 2-methoxyethanol, isopropyl alcohol, 1-propanol, 2-propanol, 2-methyl-1- Alcohols such as propanol, 1-butanol, 2-butanol, pentyl alcohol; ethers such as tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane; dimethylformamide, N-methylpyrrolidone, ethylene glycol, diethylene glycol, tri Glycols such as ethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; butanediol, pentanediol, hexanediol, diols such as diols similar to these; glycol esters such as propylene glycol laurate; diethylene glycol mono Ethyl, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol ether, dipropylene glycol ether, and glycol ethers such as cellosolve containing triethylene glycol ether; sulfolane; lactones such as γ-butyrolactone; N-(2- Lactams such as hydroxyethyl)pyrrolidone; glycerins such as glycerin, glycerin derivatives, diglycerin, diglycerin derivatives and the like, and these can be used alone or in combination of two or more.

As the organic solvent (E), in addition to the above-mentioned ones, a boiling point of 100 to 200° C. is preferable from the viewpoint of easily obtaining a quick-drying effect that the discharged droplets land on the surface of the substrate and then quickly dry on the substrate. A water-soluble organic solvent (e1) which has a vapor pressure at 20° C. of 0.5 hPa or more is preferable.

As the water-soluble organic solvent (e1), 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butyl acetate, ethylene glycol monomethyl ether, ethylene glycol Monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate , Diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, 4-methoxy-4-methyl-2-pentanone, ethyl lactate, etc., and these may be used alone or in combination of two or more. You can

Among them, as the water-soluble organic solvent (e1), it is easy to maintain good dispersion stability of the ink, and it is easy to suppress deterioration of the ink ejection nozzle of the inkjet device due to the influence of the solvent contained in the ink. From the viewpoint, it is preferable to use a water-soluble organic solvent having a hydrogen bond term δ _{H of} HSP (Hansen solubility parameter) of 6 to 30 (for example, 6 to 20).

Specific examples of the water-soluble organic solvent having a hydrogen bond term of HSP in the above range include 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether. 1 selected from the group consisting of ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monopropyl ether. One or more kinds are preferable, and one or more kinds selected from the group consisting of 3-methoxy-1-butanol and 3-methyl-3-methoxy-1-butanol are more preferable.

As an organic solvent that can be used in combination with the aqueous medium (A), propylene glycol (from the viewpoint of easily achieving the effect of quick drying of ink on the base material and the effect of preventing drying or coagulation of ink at the ink ejection port). e2) and/or it is preferable to use one or more kinds of organic solvents (e3) selected from the group consisting of glycerin, glycerin derivatives, diglycerin and diglycerin derivatives. Each of the propylene glycol (e2) and the organic solvent (e3) may be used in combination with the water-soluble organic solvent (e1).

Examples of the organic solvent (e3) include glycerin, diglycerin, polyglycerin, diglycerin fatty acid ester, polyoxypropylene (n) polyglyceryl ether represented by the following general formula (e31), and general formula (e32) below. The polyoxyethylene (n) polyglyceryl ether and the like can be used alone or in combination of two or more. Among them, the organic solvent (e3) is excellent in the setting property of the printed matter and easily obtains the effect of preventing the drying and coagulation of the ink at the ink ejection port, from the viewpoint of glycerin and polyoxypropylene (n=8 to 15). ) One or more selected from the group consisting of polyglyceryl ether is preferable.

M1, m2, n1, n2, p1, p2, q1 and q2 in the general formula (e31) and the general formula (e32) each independently represent an integer of 1 to 10.

The mass ratio of the water-soluble organic solvent (e1) to the propylene glycol (e2) [water-soluble organic solvent (e1)/propylene glycol (e2)] is excellent in the setting property of the printed matter and prevents the ink from drying or coagulating at the ink ejection port. From the viewpoint of easily obtaining the effect of prevention, 1/25 to 2/1 is preferable, 1/25 to 1/1 is more preferable, and 1/20 to 1/1 is still more preferable.

The mass ratio [propylene glycol (e2)/organic solvent (e3)] of propylene glycol (e2) to the organic solvent (e3) has an excellent effect of setting the printed matter and preventing the ink from drying or coagulating at the ink ejection port. From the viewpoint of easy acquisition, 1/4 to 8/1 is preferable, 1/3 to 6/1 is more preferable, and 1/2 to 5/1 is further preferable.

As the organic solvent (E), a solvent having a polar term of HSP of 7 or more and a hydrogen bond term of 15 or more from the viewpoint of easily obtaining good ejection stability at a level required when ejecting by an inkjet method. (E4) is preferable, and the solvent in which the polar term is 7 to 15 (particularly 7 to 12) and the hydrogen bond term is 15 to 30 (particularly 17 to 22) is more preferable.

As the solvent (e4), 1,2-propanediol, 1,2-hexanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 3-methyl-1,5- Pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 3-methyl-1,4-butanediol and the like are listed, and the viewpoint of less damage to the inkjet head, and From the viewpoint that the wettability of the ink to the substrate is improved and the settability and the adhesiveness are easily improved, 1,2-propanediol, 1,2-hexanediol, 1,4-butanediol, 1,3 -Butanediol, 1,2-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol and 3-methyl-1, At least one selected from the group consisting of 4-butanediol is preferable.

The content of the solvent (e4) is preferably 15 to 40% by mass, and preferably 15 to 25% by mass, with respect to the total amount of the ink, from the viewpoint of easily obtaining good ejection stability at a level required when ejecting by an inkjet method. % Is more preferable.

The content of the organic solvent (E) is the total amount of the ink from the viewpoint of excellent settability and from the viewpoint of easily obtaining a clear printed matter by easily obtaining a good ejection property of a level required when ejecting by an inkjet method. On the other hand, 1 to 50 mass% is preferable, 5 to 50 mass% is more preferable, 15 to 50 mass% is further preferable, and 15 to 45 mass% is particularly preferable.

(Surfactant (F))
By using the surfactant (F), the ink ejected from the ejection port of the ink jet head easily wets and spreads well on the surface after landing on the base material, and thus it is easy to prevent streaks from being generated on the printed matter. Further, by using the surfactant (F), it is possible to improve the leveling property of the ink by lowering the surface tension of the ink.

As the surfactant (F), various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. can be used, and streak-like printing defects occur. From the viewpoint of easily suppressing the above, at least one selected from the group consisting of anionic surfactants and nonionic surfactants is preferable.

Examples of the anionic surfactant include alkylbenzene sulfonate, alkylphenyl sulfonate, alkylnaphthalene sulfonate, higher fatty acid salt, higher fatty acid ester sulfate ester salt, higher fatty acid ester sulfonate, and higher alcohol ether sulfate. Ester salts and sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, etc. Specific examples thereof include dodecylbenzene sulfonate, isopropyl naphthalene sulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenyl sulfonate, dibutylphenylphenol disulfonate and the like.

As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, poly Oxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, fatty acid alkylolamide, alkylalkanolamide, acetylene glycol, acetylene glycol oxyethylene adduct, polyethylene glycol Examples thereof include polypropylene glycol block copolymers, and among these, polyoxyethylene nonylphenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester. One or more selected from the group consisting of polyoxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymer are preferable.

The ink preferably contains an acetylene-based surfactant from the viewpoint of easily suppressing the occurrence of streak-like printing defects. The acetylene-based surfactant is a surfactant having an acetylene structure in the molecule. The acetylene-based surfactant is selected from the group consisting of acetylene glycol, acetylene diol (acetylene dialcohol), and oxyethylene adduct of acetylene glycol from the viewpoint of easily suppressing the occurrence of streak-like printing defects. It is preferable that one or more species are included.

Other surfactants include silicone-based surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; Biosurfactants such as spiculisporic acid, rhamnolipid, and lysolecithin can also be used.

The content of the acetylene-based surfactant is preferably 80 to 100% by mass, and 85 to 100% by mass with respect to the total amount of the surfactant (F) from the viewpoint of easily suppressing the occurrence of streak-like printing defects. % Is more preferable, 90 to 100% by mass is further preferable, and 95 to 100% by mass is particularly preferable.

The number of carbon atoms in the main chain of the acetylene-based surfactant is preferably 20 or less, more preferably 18 or less, further preferably 15 or less, and particularly 13 or less, from the viewpoint of easily suppressing the occurrence of streak-like printing defects. 12 or less is very preferable, and 11 or less is very preferable. The number of carbon atoms in the main chain of the acetylene-based surfactant is preferably 5 or more, more preferably 8 or more, still more preferably 10 or more, from the viewpoint of easily suppressing the occurrence of streak-like printing defects. The carbon number of the main chain is the carbon number of the longest molecular chain (for example, carbon chain) containing an acetylene bond.

The HLB value of the surfactant (F) is stable from the viewpoint that it is easy to suppress the occurrence of streak-like printing defects and that the surfactant (F) is dissolved in an ink containing water as a main solvent. From the viewpoint of easy maintenance, 1-12 are preferable, 1-10 are more preferable, 2-9 are further preferable, 3-8 are particularly preferable, and 4-8 are extremely preferable. The HLB value of the acetylene-based surfactant is such that it is easy to suppress the occurrence of streak-like printing defects, and the surfactant (F) is stably maintained in the ink containing water as the main solvent. From the viewpoint of easy handling, it is preferably within these ranges. The HLB value of the surfactant (F) can be determined, for example, by the Griffin method.

The content of the surfactant (F) is preferably 0.001 to 5% by mass, more preferably 0.001 to 3% by mass, still more preferably 0.001 to 2% by mass, based on the total amount of the ink. 0.001 to 1.5% by mass is particularly preferred, 0.01 to 1.5% by mass is highly preferred, 0.1 to 1.5% by mass is highly preferred, and 0.5 to 1.5% by mass. Even more preferable, 0.8 to 1.5 mass% is still more preferable, and 1 to 1.5 mass% is particularly preferable. The ink containing the surfactant (F) in such a content has good wettability of the discharged droplets on the surface of the base material, tends to have sufficient wetting and spreading on the base material, and causes streaks on the printed matter. It is easy to obtain the effect of preventing the occurrence. Furthermore, the ink containing the surfactant (F) in each of the above ranges easily obtains the effect of improving the leveling property of the coating film. From the same viewpoint, the content of the acetylene-based surfactant is preferably within the above ranges.

(Compound (G) having a structure capable of reacting with a carbonyl group)
By using the compound (G) having a structure capable of reacting with a carbonyl group, excellent settability and adhesiveness are easily obtained. In particular, when the resin component (C) has a carbonyl group, the ink is printed on the surface of the base material, the solvent such as the aqueous medium (A) in the ink is volatilized, and then the functional group of the compound (G) is added. Since the carbonyl group reacts with the carbonyl group (for example, cross-linking accompanying dehydration condensation) to easily fix it on the surface of the substrate, it is easy to obtain more excellent settability and adhesion.

Examples of the structure capable of reacting with the carbonyl group include a hydrazine structure and a hydrazino structure. Examples of the compound (G) include adipic acid dihydrazide, sebacic acid dihydrazide, dodecane dihydrazide, isophthalic acid dihydrazide, salicylic acid dihydrazide and the like.

The content of the compound (G) is preferably 0.003 to 0.5% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the ink, from the viewpoint of easily obtaining more excellent adhesion to the substrate. Mass% is more preferable. The content of the compound (G) is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the resin component (C) from the viewpoint of easily obtaining more excellent adhesion to the substrate. The mass ratio [resin component (C)/compound (G)] of the resin component (C) and the compound (G) is preferably 20/1 to 1000/1, and 100/100 from the viewpoint of easily obtaining excellent settability. 1-500/1 is more preferable.

(Other additives)
The ink includes a wetting agent (drying inhibitor), a penetrant, an antiseptic (ACTICIDE B-20, MV4 manufactured by Saw Japan Co., Ltd.), a viscosity adjusting agent, a pH adjusting agent, a chelating agent, a plasticizer, an antioxidant. Other additives such as agents and UV absorbers may be contained.

The wetting agent can be used for the purpose of preventing the ink from drying at the ejection nozzle of the inkjet head. The content of the wetting agent is preferably 50% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less, based on the total amount of the ink. The content of the wetting agent is preferably 3% by mass or more based on the total amount of the ink.

The wetting agent is preferably one that is miscible with water and can prevent the ejection port of the inkjet head from being clogged. For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol having a molecular weight of 2000 or less, and dipropylene glycol. , Tripropylene glycol, isopropylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, mesoerythritol, pentaerythritol and the like.

Examples of penetrants include lower alcohols such as ethanol and isopropyl alcohol; ethylene oxide adducts of alkyl alcohols such as ethylene glycol hexyl ether and diethylene glycol butyl ether; propylene oxide adducts of alkyl alcohols such as propylene glycol propyl ether. The content of the penetrant is preferably 3% by mass or less, more preferably 1% by mass or less, and further preferably substantially free of the penetrant, with respect to the total amount of the ink.

(Ink manufacturing method)
The ink can be produced by mixing the aqueous medium (A) and the coloring material (B). For example, in addition to the aqueous medium (A) and the coloring material (B), a resin component (C), It can be produced by mixing the compound (D), the organic solvent (E), the surfactant (F), the compound (G) and the like.

At the time of the mixing, for example, a dispersing machine such as a bead mill, an ultrasonic homogenizer, a high pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a dyno mill, a dispermat, an SC mill, a nanomizer can be used.

An example of the method for producing the ink is a method in which the components are mixed together and then stirred, or the like.

As another example of the method for producing the ink, there is a method for producing the ink through the following steps <1> to <4>.
<1> By mixing the resin component (C) (pigment dispersant) such as the polymer (C1), the coloring material (B) such as a pigment, and the solvent, etc., if necessary, the coloring material (B) is increased. Step of producing color material dispersion a contained at a concentration <2> Step of producing composition b by mixing compound (D) with a solvent as required <3> Resin component (C) (binder Resin) and a composition c containing an aqueous medium (A), etc. <4> A step of mixing the color material dispersion a, the composition b, and the composition c

From the viewpoint of removing impurities mixed in the ink, the ink obtained by the above method is preferably subjected to a centrifugal separation treatment or a filtration treatment, if necessary.

Hereinafter, the present invention will be described with reference to experimental examples, but the present invention is not limited to the following experimental examples.

<Preparation of styrene-(meth)acrylic acid-based copolymer>
Isopropyl in a reaction vessel of an automatic polymerization reaction apparatus (polymerization tester DSL-2AS type, manufactured by Todoroki Sangyo Co., Ltd.) having a stirring vessel, a dropping apparatus, a temperature sensor, and a reaction vessel equipped with a reflux apparatus having a nitrogen introducing apparatus on the upper part. After charging 1200 parts by mass of alcohol (IPA), the inside of the reaction vessel was replaced with nitrogen while stirring.

After heating to 80° C. while maintaining the inside of the reaction vessel in a nitrogen atmosphere, 75.0 parts by mass of 2-hydroxyethyl methacrylate, 260.8 parts by mass of methacrylic acid, 400.0 parts by mass of styrene, benzyl methacrylate 234. 2 parts by mass, 30.0 parts by mass of glycidyl methacrylate, and 80.0 parts by mass of "Perbutyl (registered trademark) O" (active ingredient: t-butyl peroxy-2-ethylhexanoate, manufactured by NOF CORPORATION). The liquid was dropped from the dropping device over 4 hours. After the dropping was completed, the reaction was continued at the same temperature for 15 hours. Then, a part of isopropyl alcohol was distilled off under reduced pressure to adjust the solid content ratio to 42.5% by mass to obtain a styrene-(meth)acrylic acid copolymer (X) solution having an acid value of 170 mgKOH/g. Obtained.

<Preparation of pigment dispersion>
In a mixing tank equipped with a cooling jacket, 360 parts by mass of carbon black (CI Pigment Black 7 of Mitsubishi Chemical Corporation) and 170 parts by mass of the above-mentioned styrene-(meth)acrylic acid-based copolymer (X) solution. 61 parts by mass of 25% by mass potassium hydroxide aqueous solution, 83 parts by mass of isopropyl alcohol, and 1000 parts by mass of ion-exchanged water were charged, and then stirred by a three-one motor for 1 hour and mixed to obtain a mixed solution.

The obtained mixed liquid is passed through a dispersion device (SC mill SC100/32 type, manufactured by Mitsui Mining Co., Ltd.) filled with zirconia beads having a diameter of 0.3 mm, and a circulation system (the mixed liquid discharged from the dispersion device is A dispersion liquid was obtained by carrying out dispersion treatment by returning to the mixing tank and supplying again to the dispersion device. The dispersion treatment was performed for 4 hours while fixing the rotor peripheral speed of the dispersion device to 11.25 m/sec. During the dispersion treatment, cold water was passed through the cooling jacket to control the temperature of the mixed solution to 30° C. or lower.

The dispersion obtained by the above method was drained from the mixing tank. Next, 1500 parts by mass of water was supplied to the mixing tank to wash the mixing tank and the flow path of the dispersion device. A mixture of the water used for the washing and the dispersion was obtained as a mill dispersion.

Next, the mill dispersion liquid was placed in a glass distillation apparatus, and the total amount of isopropyl alcohol and a part of water contained in the mill dispersion liquid were distilled off. The mill dispersion liquid after the distillation was allowed to cool to room temperature, and then 2 mass% hydrochloric acid was added dropwise to the mill dispersion liquid while stirring to adjust the pH to 3.5 to obtain a reaction product. The solid content contained in the reaction product was filtered with a Nutsche filter and washed with water to obtain a wet cake.

The wet cake was placed in a container and adjusted to pH 9.0 by adding a 25% by mass aqueous potassium hydroxide solution, and redispersed with a disper (TK Homo Disper 20 model, manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, after centrifugal separation treatment (6000 G, 30 minutes), ion-exchanged water was added to obtain an aqueous pigment dispersion (K) having a solid content of 18% by mass.

<Preparation of water-based ink>
A binder, which is a core-shell acrylic polymer having a composition A (a structure having a diacetone acrylamide-derived structure (a structure having a ketone group as a carbonyl group) in the core part) in 40 parts by mass of the aqueous pigment dispersion (K), and adipine Mixture of acid dihydrazide, non-volatile content: 42 mass%, volume average particle diameter of the core-shell acrylic polymer: 50 nm, glass transition temperature of the core-shell acrylic polymer: -12°C, 17.14 parts by mass, PG (Asahi Glass Co., Ltd., propylene glycol) 20 parts by mass, ion-exchanged water 21.56 parts by mass, triethanolamine (pH adjusting agent) 0.20 parts by mass, ACTICIDE MV4 (manufactured by Saw Japan Co., preservative) 0.10 A water-based ink was obtained by adding 1 part by mass of SURFYNOL 440 (produced by Evonik Co., Ltd., an acetylene dialcohol surfactant) and stirring.

<Production of printed matter>
(Example 1)
A printed matter was prepared as follows using a printing apparatus provided with a printing unit, an electromagnetic wave irradiation unit, and a detection unit arranged in the same space.
First, in the printing section, an inkjet head KJ4B-YH manufactured by Kyocera Corporation was filled with the above-mentioned aqueous ink. Next, an OPP film (Pyrene P2161; manufactured by Toyobo Co., Ltd., biaxially stretched polypropylene film) was used by using an inkjet printing apparatus in which the head difference of the ink sub-tank from the head nozzle plate surface was set to +35 cm and negative pressure -5.0 kPa. A 100% density solid image was printed on the corona-treated surface of FIG. Then, it was dried with a warm air dryer at 60° C. for 1 minute. The gap between the inkjet head and the OPP film was set to 1.2 mm. The driving conditions of the head were the standard voltage and standard temperature of the inkjet head, and the ink droplet size was set to 18 pL.
Next, after the printed material to be printed was conveyed to the electromagnetic wave irradiation portion, the printed image of the material to be printed was irradiated with ultraviolet rays (wavelength: 254 nm, irradiation amount: 350 mJ/cm ² ) in the electromagnetic wave irradiation portion.
Immediately thereafter, the substrate to be printed was conveyed to the detection unit, and the surface of the solid print image was observed in the detection unit using ESR (EMX-Nano, manufactured by BRUKER Japan). As a result of the above observation, a signal due to radicals was observed.

(Comparative Example 1)
A printed matter was produced as described below using the printing apparatus having the same configuration as in Example 1 except that the electromagnetic wave irradiation section was not provided.
After performing printing on the material to be printed in the same manner as in Example 1, the material to be printed was immediately conveyed to the detection unit without being irradiated with electromagnetic waves, and ESR (EMX-Nano, manufactured by BRUKER Japan) was detected at the detection unit. Was used to observe the surface of the solid print image. As a result of the above observation, no signal due to radicals was observed.

Claims (4)

A printing device that obtains a printed matter by performing printing on an object to be printed,
A printing unit for printing on the printing medium,
An electromagnetic wave irradiating section for irradiating the printed material with an electromagnetic wave,
A printing unit, comprising: a detection unit that detects a signal caused by irradiation of the electromagnetic waves on the printing medium by an electron spin resonance method. The printing device according to claim 1, wherein the electromagnetic waves are ultraviolet rays. The printing device according to claim 1, wherein the electromagnetic wave irradiation unit and the detection unit are housed in the same space. A method for producing a printed matter, which comprises printing on a material to be printed to obtain a printed matter,
A printing step of printing on the printing medium,
An electromagnetic wave irradiation step of irradiating the printed material with an electromagnetic wave,
After the printing step and the electromagnetic wave irradiation step, a step of detecting a signal caused by the irradiation of the electromagnetic wave on the object to be printed by an electron spin resonance method, is provided.