JP7215136B2 - PRINTING DEVICE AND PRINTED MATERIAL MANUFACTURING METHOD - Google Patents

Description

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

2. Description of the Related Art In the production of printed matter, printed matter is obtained by printing on various printed matter such as packages and food containers. 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-A-2002-114934

2. Description of the Related Art In the production of printed matter, an object to be printed may be irradiated with electromagnetic waves for sterilization, insecticide, antibacterial treatment, and the like. In recent years, from the viewpoint of obtaining highly safe printed matter by surely performing sterilization, insecticidal, antibacterial treatment, etc., there is a demand for a method of reliably confirming that electromagnetic waves have been irradiated when obtaining printed matter.

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

A printing apparatus according to one aspect of the present invention is a printing apparatus for obtaining a printed material by performing printing on a material to be printed. An irradiation unit and a detection unit that detects a signal caused by the irradiation of the electromagnetic wave on the printing medium by an electron spin resonance method.

A method for producing a printed matter according to another aspect of the present invention is a method for producing a printed matter by printing on a substrate to be printed, comprising: a printing step of printing on the substrate to be printed; and detecting, after the printing step and the electromagnetic wave irradiation step, a signal caused by the irradiation of the electromagnetic wave on the printing medium by an electron spin resonance method.

According to the above-described printing apparatus and printed matter manufacturing method, by detecting the signal caused by the irradiation of the electromagnetic waves on the printing medium by the electron spin resonance method, it is possible to reliably confirm that the printing medium has been irradiated with the electromagnetic waves. be able to. As a result, since sterilization, insecticidal, antibacterial treatments, etc. can be reliably performed, it is also possible to reliably obtain highly safe printed matter irradiated with electromagnetic waves.

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

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. In this specification, "(meth)acrylic acid" is a general term for acrylic acid and methacrylic acid corresponding thereto, and the same applies to other similar expressions such as "(meth)acrylate". .

The printing apparatus for printed material according to the present embodiment is a printing apparatus for obtaining a printed material by performing printing on a material to be printed. and a detection unit that detects a signal caused by the irradiation of the electromagnetic wave 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 printing on a substrate to be printed. an irradiation step; and a detection step of detecting, by an electron spin resonance method, a signal caused by the irradiation of the electromagnetic wave on the printed material 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 although the printing step may be performed after the electromagnetic wave irradiation step, it is preferable to perform the electromagnetic wave irradiation step after the printing step.

According to this embodiment, by detecting the signal resulting from the irradiation of the electromagnetic waves on the printing medium by the electron spin resonance method, it is possible to reliably confirm that the printing medium has been irradiated with the electromagnetic waves. As a result, since sterilization, insecticidal, antibacterial treatments, etc. can be reliably performed, it is also possible to reliably obtain highly safe printed matter irradiated with electromagnetic waves. In this embodiment, for example, radicals are generated from the printing medium by irradiating the printing medium with electromagnetic waves, and the radicals can be detected as signals by the electron spin resonance method. The present embodiment can contribute to ensuring safety in packaging fields such as food packaging, medicine packaging, and medical equipment packaging.

According to this embodiment, it is possible to reliably determine whether or not the object to be printed is irradiated with the electromagnetic wave based on the data. According to this embodiment, by using the electron spin resonance method, it is possible to determine in a short period of time whether the object to be printed has been irradiated with electromagnetic waves, and it is easy to reduce the size of the printing apparatus.

According to the printing apparatus and the method for producing a printed matter according to the present embodiment, by irradiating an object to be printed with electromagnetic waves, sterilization treatment, insecticidal treatment, antibacterial treatment, crop growth suppression treatment (for example, sprouting prevention of potatoes), 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, secondary contamination can be prevented because these treatments can be performed while the printed matter is packaged.

According to the printing apparatus and the printed matter manufacturing method according to the present embodiment, when it is confirmed that a foreign substance is mixed in the inside of the printed matter after the printed matter is unsealed, the signal caused by the irradiation of the electromagnetic wave is detected by the electron spin resonance method. It is possible to identify the timing of foreign matter contamination by detecting by That is, when a signal is detected from the foreign matter and the printed matter, it can be identified 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 the signal is not detected from the foreign matter and the printed matter. , it can be identified that there is a possibility that foreign matter has entered after opening.

The material to be printed is not particularly limited, and includes packaging bodies, food containers, and the like. Items to be packaged in the packaging body include foods, medicines, and various instruments (medical instruments, etc.). Examples of packaging materials for packaging objects include plastic films, paper, cloth, and laminates (multilayer films, laminates, etc.) containing a plurality of these materials. Examples of plastic film constituent materials include polyesters such as polyethylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polyamides such as nylon; polystyrene; A resin etc. are mentioned. Corrugated cardboard may be used as packaging material.

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

Examples of the printing method include inkjet printing, gravure printing, flexographic printing, offset printing, etc., and inkjet printing is preferred. The printing unit may print the ink onto the printing medium. Examples of the ink include water-based ink (water-based dye ink, water-based pigment ink, etc.), solvent-based ink, etc. Water-based ink is preferable, and water-based pigment ink is more preferable. In general, when water-based ink is used, there is concern about the growth of bacteria caused by moisture. However, in the present embodiment, sterilization and antibacterial treatment can be performed by irradiating electromagnetic waves, so water-based ink is preferably used. be able to. The ink may be an edible ink.

The printing section may have a drying section 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 this embodiment may include a drying section independent of the printing section. In the printing step in the method for producing a printed matter according to the present embodiment, the ink may be dried after printing on the printing medium.

In the printing section, after the photocurable ink is printed on the printing medium, the ink may be photocured (by irradiating the ink with light). Light for photocuring includes ultraviolet rays and the like. The wavelength of light for photocuring may be, for example, 365 to 420 nm. The ink printed on the printing medium does not have to be curable (for example, photocurable).

The electromagnetic wave irradiation unit irradiates the object to be printed with electromagnetic waves. The electromagnetic wave irradiation step of the printed matter 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 perform sterilization treatment (sterilization treatment), insecticidal treatment, antibacterial treatment (e.g., suppression of bacterial growth), and crop growth suppression treatment (e.g., Potato sprout prevention), treatment for foreign matter inspection, etc. can be applied. The electromagnetic wave may be applied to at least a portion of the printing medium, or may be applied to the entire printing medium.

Electromagnetic waves include ultraviolet rays (wavelength: eg 254 nm, irradiation amount: eg 10 to 420 mJ/cm ² (350 mJ/cm ² etc.)), radiation, etc., and ultraviolet rays are preferred.

The wavelength of the ultraviolet light may be 380 nm or less, less than 365 nm, 350 nm or less, 300 nm or less, or 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, commercially available light sources such as germicidal lamps and germicidal lamps can be used. For example, a low-pressure mercury lamp using an ultraviolet-transmitting glass tube can be used.

Examples of radiation include gamma rays (eg, 25 kGy), X-rays, electron beams (eg, 10 to 30 kGy), and gamma rays emitted from cobalt-60 (Co-60) can be used. The absorbed dose of radiation can be adjusted depending on 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, or 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 points of view, the absorbed dose of radiation may range from 0.1 to 50 kGy. For sterilization/insecticide/antibacterial treatment of printed materials including medical devices, radiation of 20 to 30 kGy (eg, gamma rays) can be applied. In the sterilization/insecticide/antibacterial treatment of printed materials including food, 0.1 to 1 kGy of radiation can be irradiated for insecticidal treatment of parasites and insect pests, and 1 to 10 kGy of radiation can be irradiated for sterilization/antibacterial treatment of microorganisms.

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

At least two selected from the group consisting of the printing unit, the electromagnetic wave irradiation unit, and the detection unit in the printing device may be housed (built-in) in the same space (e.g., housing), and housed (built-in) in the same space. It does not have to be. For example, the electromagnetic wave irradiation section and the detection section 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 printed material producing section for producing a printed material. The printed material producing unit may be a package producing unit that produces a package by packaging the object to be packaged. The printed material producing section may be accommodated in the same space (for example, housing) together with at least one member selected from the group consisting of the printing section, the electromagnetic wave irradiation section, and the detection section.

The method for manufacturing a printed matter according to the present embodiment may include a printed material producing step of producing a printed material. The printed body preparing process can be performed in the printed body preparing section. The printed body producing step may be a package producing step of packaging an object to be packaged to produce a package. A printing process and an electromagnetic wave irradiation process can be performed after the process of producing a printed body.

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

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

The printing apparatus according to this embodiment may include a transport section that transports the printing medium. The conveying section has a conveying path for conveying the printed material between at least two selected from the group consisting of the printing section, the electromagnetic wave irradiation section, the detecting section, the printed material preparing section, and the substrate laminating section. good. For example, the transport section may have a series of transport paths T that transport the printing medium from the electromagnetic wave irradiation section to the detection section. The transport path T may be a transport path that transports the printing medium from the printing section to the detecting section via the electromagnetic wave irradiation section, and transports the printing medium from the electromagnetic wave irradiation section to the detection section via the printing section. It may be a transport path. The transport path T may be a transport path that transports the printing medium from the printing medium preparation section to the detection section via the printing section and the electromagnetic wave irradiation section. In the method for producing a printed matter according to the present embodiment, at least one selected from the group consisting of the printing step, the electromagnetic wave irradiation step, the detection step, the printed body preparation step, and the substrate lamination step, while conveying the printed body you can go

The printing apparatus according to this embodiment may include a control section that controls the electromagnetic wave irradiation section and the detection section. For example, after conveying the printing medium irradiated with the electromagnetic waves in the electromagnetic wave irradiation section to the detecting section, the control section detects a signal caused by the irradiation of the electromagnetic waves on the printing medium by the electron spin resonance method in the detecting section. It controls the electromagnetic wave irradiation unit and the detection unit. In this manner, 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 do not have to be interlocked. The control section may further control at least one selected from the group consisting of the printed material preparing section, the base material laminating section, the printing section, and the conveying section. In the printed matter manufacturing method according to the present embodiment, the electromagnetic wave irradiation process and the detection process may be performed while being controlled by the control unit.

Examples of constituents of ink that can be printed on a printing medium are described below. The ink can contain, for example, an aqueous medium (A) and a colorant (B). The ink may be an aqueous ink containing an aqueous medium. Ink components include 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 a resin component (C) from the viewpoint of easily obtaining printed matter having excellent scratch resistance. The ink may contain the compound (D) from the viewpoint of improving the settability of the printed matter (the ability to prevent the ink from peeling off from the substrate surface). From these points of view, the ink may contain the resin component (C) and the compound (D). In this 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 the solvent.

(Aqueous medium (A))
The ink can 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, pure water or ultrapure water such as ion-exchanged water, ultrafiltrated water, reverse osmosis water, and distilled water can be used.

The content of the aqueous medium (A) is the total amount of the ink from the viewpoint of easily obtaining an ink that has excellent setting properties and high ejection stability required when ejecting by an inkjet recording method and can produce clear printed matter. On the other hand, 1 to 98% by mass is preferable, and 5 to 95% by mass is more preferable.

(Coloring material (B))
As the coloring material (B), known and commonly used pigments, dyes, and the like can be used. Among them, as the colorant (B), a pigment is preferable from the viewpoint of easy production of a printed matter excellent in weather resistance and the like. A coloring agent in which a pigment is coated with a resin can also be used as the coloring material (B).

The pigment is not particularly limited, and inorganic or organic pigments commonly used in water-based gravure inks and water-based inkjet recording inks can be used. Examples of inorganic pigments that can be used include iron oxide and carbon black produced by a contact method, furnace method, thermal method, or the like. Examples of organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinoflurone 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 pigments and acid-treated pigments can be used.

Among the above pigments, examples of carbon black that can be used for 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.; Columbia's Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc.; , Monarch900, Monarch1000, Monarch1100, Monarch1300, Monarch1400, etc.; Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 1400U, Special Black 6, 5, 4, 4A, NIPEX150, NIPEX160, NIPEX170, NIPEX180, etc. can be used.

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

In order for the pigment to be stably present in the ink, it is preferable that a means for dispersing it well in the aqueous medium (A) is taken. Examples of the means include (i) a method of dispersing the pigment together with the resin component (C) (pigment dispersant) in the aqueous medium (A) by a dispersing method described below; (ii) imparting dispersibility to the surface of the pigment. 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, etc. to disperse a self-dispersing pigment in an aqueous medium (A). and/or a method of dissolving.

As the self-dispersing pigment, for example, a pigment is subjected to a physical or chemical treatment to bond (graft) a dispersibility-imparting group or an active species having a dispersibility-imparting group to the surface of the pigment. can do. For self-dispersing pigments, for example, vacuum plasma treatment, oxidation treatment with hypohalous acid and/or hypohalite; oxidation treatment with ozone; wet oxidation method in which the pigment surface is oxidized with an oxidizing agent in water; p-amino By bonding benzoic acid to the pigment surface, it can be produced by a method of bonding a carboxyl group via a phenyl group, or the like.

Since the water-based ink containing the self-dispersing pigment does not need to contain a pigment dispersant, there is almost no foaming caused by the pigment dispersant, and it is easy to prepare an ink with excellent ejection stability. In addition, water-based inks containing self-dispersing pigments are easy to handle and suppress a significant increase in viscosity caused by pigment dispersants. Can be used in manufacturing.

Commercially available products can be used as the self-dispersing pigment, and examples of such commercial products include Microjet CW-1 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), CAB-O-JET200, and CAB. -O-JET300 (trade name, manufactured by Cabot Corporation) and the like.

The content of the coloring material (B) is easy to prevent the occurrence of streaks, maintain excellent dispersion stability of the coloring material (B), and easily improve the print density and abrasion resistance of the printed matter. From the point of view, it is preferably 0.5 to 20% by mass, more preferably more than 0.5% by mass and 20% by mass or less, even more preferably 1 to 20% by mass, and 1.5 to 15% by mass, based on the total amount of the ink. % is particularly preferred, 2-10% by weight is very preferred, 2-8% by weight is very preferred, and 2.5-8% by weight is even more preferred.

(Resin component (C))
The ink may contain a resin component (C). The resin component (C) may be used as a pigment dispersant when a pigment is used as the colorant (B). The pigment dispersant can impart water dispersibility to the pigment particles by adsorbing on the surfaces of the pigment particles that do not have 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 resins 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, vinyl naphthalene-acrylic acid copolymers; salts of the above aqueous resins; polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone, polyolefins, urethane resins , dextran, dextrin, carrageenan (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 one or more selected from the group consisting of acrylic resins and styrene-acrylic resins. As the resin component (C), Ajinomoto Fine Techno Co., Ltd. Ajisper PB series, BYK-Chemie Japan Co., Ltd. Disperbyk series, BASF Corporation EFKA series, JONCRYL series, Nippon Lubrizol Co., Ltd. SOLSPERSE series, Evonik 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, it is easy to impart good ejection stability required when ink is ejected by an inkjet recording method.

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 the number average molecular weight is 1000 to 6000, which is capable of forming fine particles in water when the neutralization rate of the anionic group with a basic compound is 100%. It is preferred to use polymers of

The water solubility of the polymer (C1) can be defined as follows. That is, first, 0.5 g of the polymer (C1) whose particle size was adjusted to a range of 250 μm to 90 μm using sieves with 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 allowed to stand under gentle stirring for 24 hours at a temperature of 25°C. After immersion for 24 hours, the 400-mesh wire mesh enclosing the polymer (C1) is dried in a dryer set at 110° C. for 2 hours. The change in mass of the 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 fine particles are formed in water when the rate of neutralization of anionic groups by a basic compound is 100% can be determined as follows.
(1) The acid value of polymer (C1) is measured in advance by an acid value measurement method based on JIS test method K 0070-1992. Specifically, 0.5 g of polymer (C1) is dissolved in tetrahydrofuran, and the acid value is determined by titration with a 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.
(2) After adding 1 g of polymer (C1) to 50 mL of water, 0.1 mol/L potassium hydroxide aqueous solution sufficient to neutralize the obtained acid value by 100% is added to achieve 100% neutralization.
(3) Irradiate the 100% neutralized liquid with ultrasonic waves in an ultrasonic cleaner (manufactured by SND Co., Ltd., ultrasonic cleaner US-102, 38 kHz self-oscillation) at a temperature of 25 ° C. for 2 hours. After that, it is left at room temperature for 24 hours.

After standing for 24 hours, the liquid at a depth of 2 cm from the liquid surface was used as a sample liquid, and a dynamic light scattering particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., a dynamic light scattering particle size measuring device "Microtrac particle size distribution The presence of fine particles is confirmed by determining whether light scattering information due to fine particle formation can be obtained using a total UPA-ST150").

The particle diameter of the fine particles is preferably 5 to 1000 nm, more preferably 7 to 700 nm, even more preferably 10 to 500 nm, from the viewpoint of further improving the stability in water of the fine particles formed by the polymer (C1). In addition, the narrower the particle size distribution of the fine particles, the better the dispersion stability. However, even when the particle size distribution is wide, an ink having better dispersion stability than conventional inks can be obtained. In addition, the particle size and particle size distribution can be measured using a dynamic light scattering particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., a dynamic light scattering particle size measuring device "Microtrac Particle Size Distribution Meter") in the same manner as the method for measuring fine particles. UPA-ST150”).

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

The acid value of polymer (C1) can be measured according to JIS test method K 0070-1992. Specifically, it can be determined by dissolving 0.5 g of a sample in tetrahydrofuran and titrating with a 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

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

[Method for measuring number average molecular weight (Mn)]
It was measured under the following conditions by a gel permeation chromatography (GPC) method.
Measuring device: high-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation are connected in series and used.
"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 Book "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}
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

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. Polymers having hydrophobic groups in one molecule in addition to certain anionic groups can be used.

Examples of such polymers include block polymers having a polymer block having a hydrophobic group and a polymer block having an anionic group. In the polymer (C1), the number of anionic groups and the solubility in water are not necessarily specified by the acid value or the number of anionic groups at the time of polymer design. Even among polymers, those with a low molecular weight tend to have a high solubility in water, and those with a high molecular weight tend to have a 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. is preferably Moreover, the polymer (C1) may be a branched polymer, but is preferably a linear polymer.

Polymer (C1) is preferably a vinyl polymer from the viewpoint of freedom of design, and methods for producing a vinyl polymer having a desired molecular weight and solubility properties include living radical polymerization, living cationic polymerization, and living anionic polymerization. It is preferably prepared by using "living polymerization".

Among them, the polymer (C1) is preferably a vinyl polymer produced using a (meth)acrylate monomer as one of raw materials, and examples of methods for producing such a vinyl polymer include living radical polymerization and living anionic polymerization. Living anionic polymerization is preferable, and furthermore, 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 anionic 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 is , represents an integer of 1 to 5, and B represents an aromatic group or an alkyl group.

In general formula (c1), A1 represents ^an organolithium initiator residue. Specific examples of organic lithium initiators (polymerization initiators) include methyllithium, ethyllithium, propyllithium, butyllithium (n-butyllithium, sec-butyllithium, iso-butyllithium, tert-butyllithium, etc.), pentyl Alkyllithium such as lithium, hexyllithium, methoxymethyllithium, ethoxymethyllithium; benzyllithium, α-methylstyryllithium, 1,1-diphenyl-3-methylpentyllithium, 1,1-diphenylhexyllithium, phenylethyl Phenylalkylenelithium such as lithium; Alkenyllithium such as vinyllithium, allyllithium, propenyllithium and butenyllithium; Alkynyllithium such as ethynyllithium, butynyllithium, pentynyllithium and hexynyllithium; Phenyllithium and naphthyllithium aryllithium; heterocyclic lithium such as 2-thienyllithium, 4-pyridyllithium and 2-quinolyllithium; and alkyllithium magnesium complexes such as tri(n-butyl)magnesiumlithium and trimethylmagnesiumlithium.

In the organolithium initiator, the bond between the organic group and lithium is cleaved to generate an active terminal on the side of the organic group, from which polymerization is initiated. Therefore, organic groups derived from organolithium are bonded to the ends of the obtained polymer. In this specification, the organolithium-derived organic group attached to the polymer terminal is referred to as "organolithium initiator residue". For example, in the case of a polymer using methyllithium as an initiator, the organolithium initiator residue will be a methyl group, and in the case of a polymer using butyllithium as an initiator, the organolithium initiator residue will be a butyl group. .

In general formula (c1), ^A2 represents a polymer block having a hydrophobic group. A ² is preferably a group that is highly adsorbed to the pigment when in 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 A polymer block having a structural unit derived from a monomer having a heterocycle is preferred. A polymer block having a structural unit derived from a monomer having an aromatic ring or a heterocyclic ring is specifically a monomer having an aromatic ring such as a styrene-based monomer, or a monomer having a heterocyclic ring such as a vinylpyridine-based monomer. is a polymer block of a homopolymer or copolymer obtained by homopolymerizing or copolymerizing the

Examples of monomers having an aromatic ring include styrene, p-tert-butyldimethylsiloxystyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, p-tert-butoxystyrene, m-tert-butoxystyrene, Styrenic monomers such as p-tert-(1-ethoxymethyl)styrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, α-methylstyrene, p-methyl-α-methylstyrene, vinyl naphthalene, vinylanthracene and the like. Monomers having a heterocyclic ring include vinylpyridine-based monomers such as 2-vinylpyridine and 4-vinylpyridine. Each of the monomers having an aromatic ring or heterocyclic ring can be used singly or in combination of two or more.

^In general formula (c1), A3 represents a polymer block having an anionic group. A3 has the purpose of imparting appropriate solubility as described above ^, and also the purpose of imparting dispersion stability in water when it becomes a pigment dispersion.

Examples of the anionic group in the polymer block A3 include carboxyl group ^, sulfonic acid group and phosphoric acid group. Among them, a carboxyl group is preferable from the viewpoints of ease of preparation, variety of monomer types, availability, and the like. Also, two carboxyl groups may be intramolecular or intermolecular dehydration-condensed acid anhydride groups.

The method of introducing the anionic group of A3 is not particularly limited. For example ^, when the anionic group is a carboxyl group, a homopolymer or copolymer obtained by homopolymerizing (meth)acrylic acid or copolymerizing it with another monomer may be the polymer block (PB1) of, by deprotection, a homopolymer obtained by homopolymerizing (meth)acrylate having a regeneratable protecting group on the anionic group or copolymerizing it with another monomer Alternatively, it may be a polymer block (PB2) in which some or all of the protective groups regeneratable to the anionic groups of the copolymer are regenerated to anionic groups.

Specific examples of the (meth)acrylic acid and (meth)acrylate used in the polymer block A3 include ⁽ meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, and (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)acrylate 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, ( meth)tetrafluoropropyl 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, methoxypolyethyleneglycol (meth)acrylate, ethoxypolyethyleneglycol (meth)acrylate, butoxypolyethyleneglycol (meth)acrylate, octoxypolyethyleneglycol (meth)acrylate Polyethylene glycol (meth)acrylate such as lauroxypolyethyleneglycol (meth)acrylate, stearoxypolyethyleneglycol (meth)acrylate, phenoxypolyethyleneglycol (meth)acrylate, methoxypolypropyleneglycol (meth)acrylate, octoxypolyethyleneglycol-polypropyleneglycol (meth)acrylate, etc. Alkylene oxide group-containing (meth)acrylates and the like are included. These monomers can be used individually by 1 type or in mixture of 2 or more types.

In the living anionic polymerization method, if the monomer used has a group with an active proton such as an anionic group, the active terminal of the living anionic polymer immediately reacts with the group with an active proton and deactivates. , the polymer is difficult to obtain. In living anionic polymerization, it is difficult to polymerize a monomer having a group with an active proton as it is. It is preferred to regenerate the bearing groups.

For this reason, it is preferable to use a (meth)acrylate ^- containing monomer having a protective group that can be regenerated to an anionic group by deprotection in the polymer block A3. By using the monomer, the aforementioned inhibition of polymerization can be prevented during polymerization. An anionic group protected by a protecting group can be regenerated to an anionic group by deprotecting after obtaining a block polymer.

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 protecting group convertible to a carboxyl group is preferably a group having an ester bond, such as a primary alkoxycarbonyl such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, and an 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 alkoxyalkylcarbonyl groups such as

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), tridecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), nonadecyl (meth) acrylate, icosanyl (meth) acrylate) ) acrylate and other alkyl (meth)acrylates; benzyl (meth)acrylate and other phenylalkylene (meth)acrylates; ethoxyethyl (meth)acrylate and other alkoxyalkyl (meth)acrylates. These (meth)acrylates can be used singly 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 facilitating the conversion reaction to a carboxyl group, and industrial t-butyl (meth)acrylate is more preferable from the viewpoint of easy availability.

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. Further, n represents an integer of 1-5.

In the living anionic polymerization method, when an attempt is made to directly polymerize a (meth)acrylate monomer onto the active terminal of a strongly nucleophilic styrenic polymer, polymerization may fail due to nucleophilic attack on the carbonyl carbon. Therefore, when the (meth)acrylate monomer is polymerized in A ¹ -A ² , a reaction modifier can be used to adjust the nucleophilicity, and then the (meth)acrylate monomer can be polymerized. B in general formula (c1) is a group derived from a reaction modifier. Specific examples of reaction modifiers include diphenylethylene, α-methylstyrene, p-methyl-α-methylstyrene and the like.

The living anionic polymerization method can be carried out by a batch system as used in conventional free radical polymerization by adjusting the reaction conditions, or by a continuous polymerization method using a microreactor. Since the microreactor has good miscibility between the polymerization initiator and the monomer, the reactions start at the same time, the temperature is uniform, and the polymerization rate can be uniformed, so that the molecular weight distribution of the produced polymer can be narrowed. At the same time, since the growing ends are stable, it becomes easy to produce a block copolymer in which both block components are not mixed. In addition, since the controllability of the reaction temperature is good, it is easy to suppress side reactions.

After that, a block copolymer is produced by quenching the reaction with a compound having an active proton (methanol, etc.).

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 heterocyclic ring) is used as the first monomer. Then, by reacting using an organic lithium initiator as a polymerization initiator, A ² , a polymer block having a hydrophobic group (e.g., a polymer block having a structural unit derived from a monomer having an aromatic ring or a heterocyclic ring) ( ^One end of the polymer block ^A2 is bound to an organic group which is the organolithium initiator residue of A1).

Next, after adjusting the reactivity of the growing terminal using a reaction modifier, a monomer containing a (meth)acrylate having a regeneratable protecting group for the anionic group is reacted as the second monomer to obtain a polymer. get a block

After that, the anionic group is regenerated by a deprotection reaction such as hydrolysis to obtain the A ³ (that is, the polymer block containing the anionic group).

A method for regenerating an anionic group by a deprotection reaction such as hydrolysis of an ester bond of a protective group capable of regenerating the anionic group will be described in detail below.

The hydrolysis reaction of an ester bond proceeds under both acidic and basic conditions, but the conditions differ slightly 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 is performed under basic conditions. A carboxyl group can be obtained. At this time, examples of the basic compound used under basic conditions include metal hydroxides such as sodium hydroxide and potassium hydroxide.

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

As a method for converting a t-butoxycarbonyl group to a carboxyl group, for example, a method using a cation exchange resin in place of the above acid can be mentioned. Examples of cation exchange resins include resins having acid groups such as carboxyl groups (--COOH) and sulfo groups (--SO ₃ H) in side chains of polymer chains. 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 progress of the reaction can be accelerated. 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 to a carboxyl group by hydrogenation reduction reaction. At this time, as the reaction conditions, the phenylalkoxycarbonyl group can be quantitatively regenerated to the carboxyl group by reacting with hydrogen gas as a reducing agent at room temperature in the presence of a palladium catalyst such as palladium acetate.

As described above ^, the reaction conditions for conversion to a carboxyl group differ depending on the type of group having an ester bond. A polymer obtained by copolymerization using will have a t-butoxycarbonyl group and an n-butoxycarbonyl group. Here, since the n-butoxycarbonyl group does not hydrolyze under acidic conditions where the t-butoxycarbonyl group hydrolyzes, it is possible to selectively hydrolyze only the t-butoxycarbonyl group to deprotect the carboxyl group. becomes. Therefore, it is possible to adjust the acid value of the hydrophilic block (A ³ ) by appropriately selecting a monomer containing a (meth)acrylate having a regeneratable protective group for the anionic group, which is a raw material monomer for A ³ .

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 ( A ³ ) is not a random copolymer in which A 3 ) is randomly arranged and bonded, but a block copolymer in which the polymer blocks are regularly bonded together in 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 the 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 in an inkjet recording method, and from the viewpoint of color development. 100:10 to 100:500 is preferable, and 100:10 to 100:450 is more preferable, from the viewpoint of easily obtaining an ink capable of producing a printed matter having even better properties.

In the polymer (C1) represented by the general formula (c1), the number of aromatic ring- or heterocyclic ring-containing monomers that give the polymer block (A ² ) is preferably 5 to 40, more preferably 6 to 30, and 7 to 25 is more preferred. The number of anionic groups constituting the polymer block (A ³ ) is preferably 3-20, more preferably 4-17, even more preferably 5-15.

The molar ratio A ² : A ³ of the polymer block (A ² ) and the polymer block (A ³ ) is the number of moles of the aromatic ring or heterocyclic ring constituting the polymer block (A ² ) and the polymer block (A ³ ). It is preferably 100:7.5 to 100:400 when represented by the 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 easy maintenance of good ejection stability required when ejecting ink in an inkjet recording method, and from the point of view of abrasion resistance and the like. 40 to 400 mgKOH/g is preferable, 40 to 300 mgKOH/g is more preferable, and 40 to 190 mgKOH/g is even more preferable, from the viewpoint of easily obtaining an ink capable of producing even more excellent prints. The acid value of the polymer (C1) was determined by the same acid value measurement method as the fine particle measurement method of the polymer (C1).

The anionic groups of polymer (C1) are preferably neutralized. As the basic compound that neutralizes the anionic groups of the polymer (C1), any known and commonly used basic compound can be used, for example, 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 neutralized amount of polymer (C1) present in the aqueous pigment dispersion need not be 100% neutralized relative 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 property and adhesion. A 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 acrylic resins having an aldehyde group, acrylic resins having a ketone group, acrylic resins having an amide group, and acrylic resins having a carboxyl group. Resins are preferred.

A binder resin having a carbonyl group can be obtained by polymerizing a monomer component containing a monomer having a carbonyl group, and a monomer having a carbonyl group, another monomer, may be obtained by polymerizing a monomer component containing A solution polymerization method, an emulsion polymerization method, etc. are mentioned as the polymerization method of a monomer.

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

Examples of acrylic monomers having an amide group include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, and 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, acrylamide, N,N-dimethyl (meth)acrylamide and the like can be used.

Other monomers that can be used in the production of the acrylic resin include, for example, (meth)acrylic acid and alkali metal salts thereof; methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2 - Ethylhexyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate and other (meth) acrylate monomers; (meth) acrylonitrile, 2-dimethylaminoethyl (meth) acrylate, glycidyl ( Acrylic monomers such as meth)acrylates; 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-acetoacetoxyethyl methacrylate, 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 amide group-containing acrylic resin imparts the effect of improving the redispersibility to the ink and has excellent 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 from the viewpoint of further improving the redispersibility of the ink and the dispersion stability of the ink component in the aqueous medium (A). Therefore, it is preferably 0.5 to 5% by mass, more preferably 0.5 to 4% by mass, and still more preferably 1.5 to 3% by mass, based on 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 for molecular weight measurement by gel permeation chromatography, and whose molecular weight is difficult to measure. From the viewpoint of further improving the adhesion of ink to plastics and metals that do not easily absorb solvents such as water, or highly hydrophobic coated paper and art paper, the content of THF-insoluble components at 25 ° C. is 20 mass. %, more preferably less than 5% by mass, and still more preferably no THF-insoluble components.

The number average molecular weight of the acrylic resin (eg, acrylic resin soluble in THF) is preferably 10,000 to 100,000, more preferably 20,000 to 100,000. The acrylic resin preferably has a weight average molecular weight of 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 olefinic monomer as a main component can be used. Examples of olefinic monomers that can be used include α-olefins such as ethylene, propylene, butene, hexene, methylbutene, methylpentene and methylhexene; and cyclic olefins such as norbornene.

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

The melting point of the polyolefin is preferably from 90 to 200°C, more preferably from 120°C to less than 160°C. In these cases, it is possible to impart good settability such that the ink on the surface of the base material does not peel off and excellent abrasion resistance even when printed matter is superimposed immediately after printing. The melting point of polyolefin refers to the value measured by a melting point measuring apparatus conforming to JIS K 0064.

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

In that case, the average particle diameter of the polyolefin particles formed by the polyolefin is, for example, 10 from the viewpoint of easily achieving both good ink ejection stability and good settability after printing when printing by an inkjet recording method. ~200 nm is preferable, and 30 to 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.

A so-called core-shell type polymer can be used as the resin component (C), and a polymer having a carbonyl group in either or both of the core portion and the shell portion can be used. As the resin component (C), a carbonyl group such as an amide group is used from the viewpoint of easily obtaining excellent adhesion to a difficult-to-adhere substrate and an excellent level of ejection stability required when ejecting by an inkjet method. A core-shell type polymer having at the core portion is preferred. As the core-shell type polymer, from the viewpoint of easily obtaining a more excellent level of ejection stability required when ejecting 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 portion containing an acrylic resin.

The glass transition temperature of the resin component (C) is from -12 to -12 from the viewpoint of easily obtaining excellent adhesion to a difficult-to-adhere substrate and an excellent level of ejection stability required when ejecting by an inkjet method. 25°C is preferred. The glass transition temperature of the resin component (C) can be obtained as a theoretically calculated value obtained by the following FOX formula 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
[Wherein, Tg is the glass transition temperature (unit: K) of the vinyl polymer, W1, W2, . Tgn is the glass transition temperature of the homopolymer of each monomer. ]

The resin component (C) is a viewpoint that it is easy to obtain excellent adhesion to a difficult-to-adhere substrate, a viewpoint that it is easy to prevent the occurrence of the streaks, and the printing density and abrasion resistance of the printed matter. From the viewpoint of imparting a good gloss, the total amount of the ink is preferably 1 to 10% by mass, more preferably 2 to 9% by mass, still more preferably 2 to 9% by mass, and particularly preferably 2 to 9% by mass. 3 to 9% by weight is highly preferred. Ink containing the resin component (C) within these ranges further improves the abrasion resistance of printed matter by cross-linking the resin component (C) through a heating process after printing to form a strong film. can be made In addition, even when water is dripped onto the printed material or rubbed with a water-containing cloth or the like, the ink on the surface of the base material does not peel off, so that 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, it is possible to impart good settability to the printed matter and excellent abrasion resistance.

(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. Urea and urea derivatives have a high moisturizing effect and function as a wetting agent, so they prevent drying and solidification of the ink at the ink ejection port of the inkjet head, making it easy to ensure excellent ejection stability. It has a mitigating effect. In addition, since urea and urea derivatives are likely to release water when heated, from the viewpoint of obtaining printed matter with even better setting properties, when using urea or urea derivatives, non-absorbent or difficult-to-absorb absorbents are preferred. Heat drying is preferably performed after printing the ink on the recording medium.

Urea derivatives include ethylene urea, propylene urea, diethyl urea, thiourea, N,N-dimethyl urea, hydroxyethyl urea (eg, 2-hydroxyethyl urea), hydroxybutyl urea, ethylene thiourea, diethyl thiourea, and the like. These can be used singly or in combination of two or more. Among them, the compound (D) is preferably one or more selected from the group consisting of urea, ethylene urea and 2-hydroxyethyl urea, from the viewpoint of obtaining printed matter having even better setting properties.

The content of the compound (D) is 1 to 20% by mass with respect to the total amount of the ink from the viewpoint of the ejection stability required when the ink is ejected by an inkjet recording method and the printed matter with excellent settability. 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)] has the effect of improving the settability of the printed matter. 1/6 to 6/1 is preferable, 1/6 to 3/1 is more preferable, and 1/5 to 1/1 is still more preferable from the viewpoint of easy obtaining.

(Organic solvent (E))
Examples of the organic solvent (E) include 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 and pentyl alcohol; ethers such as tetrahydrofuran, 1,4-dioxane and 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; diols such as butanediol, pentanediol, hexanediol and their homologous diols; glycol esters such as propylene glycol laurate; Ethyl, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol ether, dipropylene glycol ether, and glycol ethers such as cellosolve including 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, etc., and these can be used singly or in combination of two or more.

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

Water-soluble organic solvents (e1) include 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 and the like, and these may be used alone or in combination of two or more. can be done.

Among them, the water-soluble organic solvent (e1) is easy to maintain good dispersion stability of the ink and, for example, it is easy to suppress deterioration of the ink ejection nozzle provided in the inkjet device due to the influence of the solvent contained in the ink. From the point of view, it is preferable to use a water-soluble organic solvent having an HSP (Hansen Solubility Parameter) hydrogen bond term _δH of 6 to 30 (eg, 6 to 20).

Specific examples of the water-soluble organic solvent having an HSP hydrogen bond term within the above range include 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, ethylene glycol monomethyl ether, and 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, and propylene glycol monopropyl ether 1 selected from the group consisting of More than one species is preferred, and one or more selected from the group consisting of 3-methoxy-1-butanol and 3-methyl-3-methoxy-1-butanol is more preferred.

As an organic solvent that can be used in combination with the aqueous medium (A), propylene glycol ( It is preferred to use e2) and/or one or more 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. Polyoxyethylene (n) polyglyceryl ether and the like can be used singly or in combination of two or more. Among them, the organic solvent (e3) is excellent in settability of the printed matter, and from the viewpoint that it is easy to obtain the effect of preventing drying and solidification of the ink at the ink ejection port, glycerin and polyoxypropylene (n = 8 to 15) (n ) one or more selected from the group consisting of polyglyceryl ethers.

m1, m2, n1, n2, p1, p2, q1 and q2 in general formula (e31) and general formula (e32) each independently represents 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 settability of printed matter and prevents drying and solidification of ink at the ink ejection port. From the viewpoint of easily obtaining the effect of preventing, 1/25 to 2/1 is preferable, 1/25 to 1/1 is more preferable, and 1/20 to 1/1 is even more preferable.

The mass ratio of the propylene glycol (e2) to the organic solvent (e3) [propylene glycol (e2)/organic solvent (e3)] is excellent in settability of the printed matter and has the effect of preventing drying and solidification of the ink at the ink ejection port. From the viewpoint of easy availability, 1/4 to 8/1 is preferred, 1/3 to 6/1 is more preferred, and 1/2 to 5/1 is even more preferred.

As the organic solvent (E), a solvent having a polarity term of HSP of 7 or more and a hydrogen bond term of 15 or more from the viewpoint of easily obtaining a good level of discharge stability required when discharging by an inkjet method. (e4) is preferred, and a solvent in which the polar term is 7 to 15 (especially 7 to 12) and the hydrogen bond term is 15 to 30 (especially 17 to 22) is more preferred.

Examples of the solvent (e4) include 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, from the viewpoint of less damage to the inkjet head, and , 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 preferred.

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

The content of the organic solvent (E) is the total amount of the ink, from the viewpoint of excellent setting properties, and from the viewpoint of easily obtaining a clear printed matter by easily obtaining a good level of jetting properties required when jetting by an inkjet method. is preferably 1 to 50% by mass, more preferably 5 to 50% by mass, still more preferably 15 to 50% by mass, and particularly preferably 15 to 45% by mass.

(Surfactant (F))
By using the surfactant (F), after the ink ejected from the ejection port of the inkjet head lands on the base material, it is easy to wet and spread on the surface. Furthermore, 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. From the viewpoint of easily suppressing, one or more selected from the group consisting of anionic surfactants and nonionic surfactants is preferred.

Examples of anionic surfactants include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfuric acid ester salts of higher fatty acid esters, sulfonates of higher fatty acid esters, and sulfuric acid of higher alcohol ethers. ester salts and sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, etc.; Specific examples include dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, and dibutylphenylphenoldisulfonate.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, 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, oxyethylene adduct of acetylene glycol, polyethylene glycol and polypropylene glycol block copolymers, among which polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester. , polyoxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymer.

The ink preferably contains an acetylenic surfactant from the viewpoint of easily suppressing the occurrence of streak-like printing defects. Acetylene-based surfactants are surfactants having an acetylene structure in the molecule. Acetylene-based surfactants are selected from the group consisting of acetylene glycol, acetylene diol (acetylene dialcohol), and oxyethylene adducts of acetylene glycol, from the viewpoint of easily suppressing the occurrence of streak-like printing defects. It preferably contains more than one species.

Other surfactants include silicone-based surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkylcarboxylates, perfluoroalkylsulfonates, and oxyethylene perfluoroalkyl ethers; Biosurfactants such as spiculisporic acid, rhamnolipids, lysolecithin and the like can also be used.

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

The number of carbon atoms in the main chain of the acetylenic surfactant is preferably 20 or less, more preferably 18 or less, still more preferably 15 or less, and particularly 13 or less, from the viewpoint of easily suppressing the occurrence of streak-like printing defects. Preferably, 12 or less is highly preferred, and 11 or less is very preferred. The number of carbon atoms in the main chain of the acetylenic surfactant is preferably 5 or more, more preferably 8 or more, and even more preferably 10 or more, from the viewpoint of easily suppressing the occurrence of streak-like printing defects. The number of carbon atoms in the main chain is the number of carbon atoms in the longest molecular chain (eg, carbon chain) containing acetylene bonds.

The HLB value of the surfactant (F) is from the viewpoint of easily suppressing the occurrence of streak-like printing defects, and from the viewpoint of stably maintaining the state in which the surfactant (F) is dissolved in the ink containing water as the main solvent. From the viewpoint of easy maintenance, 1 to 12 are preferred, 1 to 10 are more preferred, 2 to 9 are even more preferred, 3 to 8 are particularly preferred, and 4 to 8 are extremely preferred. The HLB value of the acetylenic surfactant is from the viewpoint of easily suppressing the occurrence of streak-like printing defects, and stably maintains the state in which the surfactant (F) is dissolved in the ink whose main solvent is water. These ranges are preferable from the viewpoint of ease of operation. 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, even more preferably 0.001 to 2% by mass, relative to the total amount of the ink. 0.001 to 1.5% by weight is particularly preferred, 0.01 to 1.5% by weight is particularly preferred, 0.1 to 1.5% by weight is very preferred, 0.5 to 1.5% by weight is More preferably, 0.8 to 1.5% by mass is more preferable, and 1 to 1.5% by mass is particularly preferable. The ink containing the surfactant (F) at these contents has good wettability of ejected droplets on the surface of the base material, tends to spread sufficiently on the base material, and prevents streaks in printed matter. It is easy to obtain the effect of preventing occurrence. Furthermore, the ink containing the surfactant (F) within each of the above ranges tends to obtain the effect of improving the leveling properties of the coating film. From the same point of view, it is preferable that the content of the acetylenic surfactant is within the ranges described above.

(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 setting property and adhesion can be easily obtained. In particular, when the resin component (C) has a carbonyl group, the ink is printed on the surface of the base material, and after volatilization of the solvent such as the aqueous medium (A) in the ink, the functional group of the compound (G) and By reacting with the carbonyl group (for example, cross-linking due to dehydration condensation), it is easily fixed on the surface of the base material, so that it is easy to obtain even better setting property and adhesion.

A hydrazine structure, a hydrazino structure, etc. are mentioned as a structure which can react with a carbonyl group. Compound (G) includes adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, isophthalic acid dihydrazide, salicylic acid dihydrazide and the like.

The content of the compound (G) is preferably 0.003 to 0.5% by mass, more preferably 0.01 to 0.5% by mass, based on the total amount of the ink, from the viewpoint of easily obtaining excellent adhesion to the substrate. % by mass is more preferred. 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 excellent adhesion to the substrate. The mass ratio of the resin component (C) and the compound (G) [resin component (C)/compound (G)] is preferably 20/1 to 1000/1, and 100/1 from the viewpoint of easily obtaining excellent setting properties. 1 to 500/1 is more preferable.

(Other additives)
The ink contains a wetting agent (drying inhibitor), a penetrant, a preservative (ACTICIDE B-20, MV4, etc. manufactured by Thor Japan Co., Ltd.), a viscosity adjuster, a pH adjuster, a chelating agent, a plasticizer, and an antioxidant. Other additives such as agents, UV absorbers, etc. can be contained.

A wetting agent can be used for the purpose of preventing drying of the ink in the ejection nozzles of the inkjet head. The content of the humectant is preferably 50% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the total amount of the ink. The content of the humectant is preferably 3% by mass or more with respect to the total amount of ink.

The wetting agent is preferably one that is miscible with water and has an effect of preventing clogging of the ejection port of the inkjet head. Examples thereof include 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.

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; and 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 still more preferably substantially no penetrant, relative to the total amount of the ink.

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

For the mixing, 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, and a nanomizer can be used.

As an example of the ink manufacturing method, there is a manufacturing method in which each component is collectively mixed and then stirred.

Another example of the ink manufacturing method includes a manufacturing method through the following steps <1> to <4>.
<1> Resin component (C) (pigment dispersant) such as polymer (C1), colorant (B) such as pigment, and, if necessary, a solvent or the like are mixed to increase the colorant (B). <2> Step of producing composition b by mixing compound (D) and, if necessary, a solvent <3> Resin component (C) (binder <4> Step of mixing the colorant 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 as necessary.

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

<Preparation of styrene-(meth)acrylic acid-based copolymer>
Isopropyl is added to the reaction vessel of an automatic polymerization reactor (polymerization tester DSL-2AS type, manufactured by Todoroki Sangyo Co., Ltd.) having a reaction vessel equipped with a stirring device, a dropping device, a temperature sensor, and a reflux device having a nitrogen introduction device at the top. After charging 1200 parts by mass of alcohol (IPA), the inside of the reaction vessel was replaced with nitrogen while stirring.

After raising the temperature 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, and 234.5 parts by mass of benzyl methacrylate were added. 2 parts by mass, 30.0 parts by mass of glycidyl methacrylate, and "Perbutyl (registered trademark) O" (active ingredient: t-butyl peroxy 2-ethylhexanoate, manufactured by NOF Corporation) 80.0 parts by mass. The liquid was dropped from the dropping device over 4 hours. After the dropwise addition was completed, the reaction was continued at the same temperature for 15 hours. After that, part of the isopropyl alcohol was distilled off under reduced pressure to adjust the solid content ratio to 42.5% by mass, thereby obtaining 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 (Mitsubishi Chemical Co., Ltd. CI Pigment Black 7) and 170 parts by mass of the above-mentioned styrene-(meth)acrylic acid copolymer (X) solution , 61 parts by mass of a 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 and mixed for 1 hour with a three-one motor to obtain a mixed solution.

The obtained mixed solution is passed through a dispersing 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 solution discharged from the dispersing device A dispersion liquid was obtained by dispersing by a system of returning to the mixing tank and supplying to the dispersing device again). The dispersion treatment was carried out for 4 hours with the rotor peripheral speed of the dispersion device fixed at 11.25 m/sec. Also, during the dispersion treatment, cold water was passed through the cooling jacket to control the temperature of the mixed liquid to be kept at 30° C. or less.

The dispersion liquid obtained by the above method was withdrawn from the mixing tank. Next, 1500 parts by mass of water was supplied to the mixing tank to wash the channels of the mixing tank and the dispersing device. A mill dispersion was obtained by mixing the water used for the washing and the dispersion.

Next, the mill dispersion was placed in a glass distillation apparatus, and the entire amount of isopropyl alcohol and part of the water contained in the mill dispersion were distilled off. After the mill dispersion after the distillation was allowed to cool to room temperature, 2% by mass hydrochloric acid was added dropwise while stirring the mill dispersion to adjust the pH to 3.5, thereby obtaining a reaction product. A 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, adjusted to pH 9.0 by adding a 25% by mass potassium hydroxide aqueous solution, and redispersed with a disper (TK Homo Disper 20, manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, after centrifugation 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 aqueous ink>
To 40 parts by mass of the aqueous pigment dispersion (K), composition A (a binder that is a core-shell type acrylic polymer having a structure derived from diacetone acrylamide in the core (structure having a ketone group as a carbonyl group), and adipine Mixture of acid dihydrazide, nonvolatile content: 42% by mass, volume average particle diameter of the core-shell type acrylic polymer: 50 nm, glass transition temperature of the core-shell type acrylic polymer: -12°C) 17.14 parts by mass, PG (Asahi Glass Co., Ltd., propylene glycol) 20 parts by mass, deionized water 21.56 parts by mass, triethanolamine (pH adjuster) 0.20 parts by mass, ACTICIDE MV4 (manufactured by Thor Japan Co., Ltd., preservative) 0.10 Parts by mass and 1 part by mass of SURFYNOL 440 (produced by Evonik, acetylene dialcohol-based surfactant) were added and stirred to obtain an aqueous ink.

<Production of printed matter>
(Example 1)
Using a printing apparatus having a printing unit, an electromagnetic wave irradiation unit, and a detection unit arranged in the same space, a printed matter was produced as follows.
First, in the printing section, an inkjet head KJ4B-YH manufactured by Kyocera Corporation was filled with the water-based ink described above. Next, an OPP film (Pylen P2161; Toyobo Co., Ltd., biaxially oriented polypropylene film ) was printed with a 100% density solid image on the corona treated side. Then, it was dried for 1 minute with a hot air dryer at 60°C. A 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 conveying the printed material to the electromagnetic wave irradiation section, the printed image on the printed material was irradiated with ultraviolet rays (wavelength: 254 nm, irradiation amount: 350 mJ/cm ² ) in the electromagnetic wave irradiation section.
Immediately after that, the printing medium was transported to the detection section, and the surface of the solid printed image was observed in the detection section using an ESR (EMX-Nano, manufactured by BRUKER Japan). As a result of the observation, a signal caused by radicals was observed.

(Comparative example 1)
Using a printing apparatus having the same configuration as in Example 1 except that it did not include an electromagnetic wave irradiation unit, a printed material was produced as follows.
After printing on the printing material in the same manner as in Example 1, the printing material is immediately conveyed to the detection unit without being irradiated with electromagnetic waves, and in the detection unit, ESR (EMX-Nano, manufactured by BRUKER Japan). was used to observe the surface of the solid printed image. As a result of the above observations, no signal due to radicals was observed.

Claims (4)

A printing device for printing on a printing material to obtain a printed matter,
a printing unit that prints on the printing medium with water- based ink ;
an electromagnetic wave irradiation unit for irradiating the object to be printed with an electromagnetic wave;
a detection unit that detects a signal caused by the irradiation of the electromagnetic wave on the printing medium by an electron spin resonance method ;
A printing apparatus, wherein the printing unit has a drying unit that dries water-based ink printed on the printing medium . 2. The printing apparatus according to claim 1, wherein said electromagnetic waves are ultraviolet rays. 3. The printing apparatus according to claim 1, wherein said electromagnetic wave irradiation section and said detection section are housed in the same space. A printed matter manufacturing method for obtaining a printed matter by printing on a printing material,
a printing step of drying the water-based ink after printing the material to be printed with water -based ink;
an electromagnetic wave irradiation step of irradiating the object to be printed with an electromagnetic wave;
A method for producing a printed matter, comprising, after the printing step and the electromagnetic wave irradiation step, detecting a signal caused by the irradiation of the electromagnetic wave on the object to be printed by an electron spin resonance method.