Inkjet ink composition and recording method

Abstract

To provide an inkjet ink composition which enables formation of an image having good scratch resistance and color development property.SOLUTION: An inkjet ink composition is aqueous ink which contains a water-soluble low molecular organic compound A that is any one of a coloring material, a resin, amides, sulfur-containing materials, and cyclic ethers and satisfies the following condition (a) and condition (b), and a silicone-based surface active agent satisfying the following condition (c). Condition (a): surface tension of 10 mass% aqueous solution of 42 mN / m or more and 56 mN / m or less. Condition (b): standard boiling point of 150°C or higher and 300°C or lower. Condition (c): solubility to water at 20°C of 1 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an inkjet ink composition and a recording method. [Background technology]

[0002] Because the inkjet method can form high-quality images on recording media, various technological developments have been undertaken over the years. For example, not only is there active development of recording devices using the inkjet method, but also of inkjet ink compositions used in such devices. Furthermore, attempts are being made to solve various problems related to combinations of recording devices, inkjet ink compositions, recording media, etc.

[0003] For example, Patent Document 1 discloses a recording method in which an inkjet ink composition containing a resin component is applied to a recording medium with an uneven surface, and the resin component is dissolved by incorporating a nitrogen-containing solvent into the ink composition to improve scratch resistance. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-134801 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, it has become clear that when using solvents to dissolve the resin components in inkjet ink compositions, sufficient abrasion resistance cannot be obtained depending on the solvent.

[0006] Furthermore, it has been found that using a solvent to dissolve the resin components results in poor color reproduction in the resulting images.

[0007] Thus, inkjet ink compositions that can form images with good scratch resistance and color development were still insufficient.

Means for Solving the Problem

[0008] One aspect of the inkjet ink composition according to the present invention is a coloring material, a resin, a water-soluble low molecular weight organic compound A which is any one of amides, sulfur-containing compounds, and cyclic ethers and satisfies the following conditions (a) and (b), a silicone surfactant satisfying the following condition (c), and is an aqueous ink containing Condition (a): The surface tension of a 10 mass% aqueous solution is 42 mN / m or more and 56 mN / m or less Condition (b): The standard boiling point is 150°C or more and 300°C or less Condition (c): The solubility in water at 20°C is 1 mass% or less

[0009] One aspect of the recording method according to the present invention is provided with an ink adhesion step of adhering the above-described inkjet ink composition to a recording medium by an inkjet method.

Brief Description of the Drawings

[0010] [Figure 1] Schematic diagram of an example of an inkjet recording apparatus used in the recording method of the embodiment. [Figure 2] Schematic diagram around the carriage of an example of an inkjet recording apparatus used in the recording method of the embodiment. [Figure 3] Block diagram of an example of an inkjet recording apparatus used in the recording method of the embodiment. [Figure 4] Flowchart showing an example of the processing performed when recording is carried out with an inkjet recording apparatus used in the recording method of the embodiment.

Mode for Carrying Out the Invention

[0011] Embodiments of the present invention will be described below. The embodiments described below illustrate examples of the present invention. The present invention is not limited to the following embodiments, and also includes various modified forms implemented within the scope of not changing the gist of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

[0012] In this specification, “(meth)acrylic” represents acrylic or methacrylic, and “(meth)acrylate” represents acrylate or methacrylate.

[0013] 1. Inkjet Ink Composition The inkjet ink composition according to this embodiment is an aqueous ink containing a coloring material, a resin, a water-soluble low-molecular organic compound A which is any one of amides, sulfur-containing compounds, and cyclic ethers and satisfies the following conditions (a) and (b), and a silicone surfactant that satisfies the following condition (c). Condition (a) The surface tension of a 10% by mass aqueous solution is 42 mN / m or more and 56 mN / m or less. Condition (b) The standard boiling point is 150°C or more and 300°C or less. Condition (c) The solubility in water at 20°C is 1% by mass or less. Hereinafter, the inkjet ink composition and its components of this embodiment will be described.

[0014] When using a solvent that dissolves the resin component in the inkjet ink composition, it has been found that sufficient rubbing resistance cannot be obtained depending on the solvent. Specifically, when the surface tension of the solvent is low, the solvent easily penetrates into the recording medium, and it is presumed that the solvent penetrates into the recording medium and cannot sufficiently dissolve the resin component contained in the inkjet ink composition on the recording medium.

[0015] Furthermore, it has also been found that when using a solvent with a high surface tension as the solvent for dissolving the resin component, the color development of the obtained image deteriorates. This is presumed to be because the solvent does not easily spread by wetting on the recording medium, and the wetting spread of the inkjet ink composition on the recording medium becomes insufficient.

[0016] Therefore, the inkjet ink composition of this embodiment contains the above-mentioned low-molecular-weight organic compound A and the above-mentioned specific silicone-based surfactant, thereby providing an inkjet ink composition that can form images with good scratch resistance and color development.

[0017] 1.1. Colorants The inkjet ink composition contains a colorant. The colorant may be a pigment or a dye.

[0018] (Pigment) As pigments, inorganic pigments including carbon black and titanium white, organic pigments, etc., can be used.

[0019] Inorganic pigments that can be used include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, as well as iron oxide, titanium oxide, zinc oxide, silica, and the like.

[0020] Examples of carbon black include Mitsubishi Chemical Corporation's No. 2300, 900, MCF88, No. 20B, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, and No. 2200B. Examples of Degussa's Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Pritex 35, U, V, 140U, and Special Black 6, 5, 4A, 4, and 250. Examples of Columbia Carbon's Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, and 700. Examples include Cabot's Regal 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, and Elftex 12.

[0021] Examples of organic pigments include quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, ancenthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimimidazolone pigments, isoindolinone pigments, azomethine pigments, or azo pigments.

[0022] Specific examples of organic pigments used in inkjet ink compositions include the following:

[0023] Examples of cyan pigments include CI Pigment Blue 1, 2, 3, 15:3, 15:4, 15:34, 16, 22, 60, etc.; CI Bat Blue 4, 60, etc. Preferably, one or more mixtures selected from the group consisting of CI Pigment Blue 15:3, 15:4, and 60 can be exemplified.

[0024] Examples of magenta pigments include CI Pigment Red 5, 7, 12, 48(Ca), 48(Mn), 57(Ca), 57:1, 112, 122, 123, 168, 184, 202, and CI Pigment Violet 19. Preferably, one or more mixtures selected from the group consisting of CI Pigment Red 122, 202, and 209, and CI Pigment Violet 19 can be exemplified.

[0025] Examples of yellow pigments include CI Pigment Yellow 1, 2, 3, 12, 13, 14C, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 119, 110, 114, 128, 129, 138, 150, 151, 154, 155, 180, 185, etc. Preferably, one or more mixtures selected from the group consisting of CI Pigment Yellow 74, 109, 110, 128, 138, 155, and 180 can be exemplified.

[0026] Examples of orange pigments include CI Pigment Orange 36 or 43, or mixtures thereof. Examples of green pigments include CI Pigment Green 7 or 36, or mixtures thereof.

[0027] Furthermore, lustrous pigments may be used, and are not particularly limited as long as they exhibit lustrous properties when attached to a medium. Examples include metal particles of one or more alloys (also called metallic pigments) selected from the group consisting of aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, and copper, or pearl pigments having a pearlescent luster. Typical examples of pearl pigments include titanium dioxide-coated mica, fish scale foil, and bismuth acid chloride, which are pigments that have a pearlescent or interference luster. In addition, lustrous pigments may be subjected to surface treatment to suppress their reaction with water.

[0028] White pigments may also be used, such as metal oxides, barium sulfate, and calcium carbonate. Examples of metal oxides include titanium dioxide, zinc oxide, silica, alumina, and magnesium oxide. Furthermore, particles with a hollow structure may be used as the white pigment.

[0029] The above pigments may be used individually or in combination of two or more. From the viewpoint of storage stability, such as lightfastness, weather resistance, and gas resistance, organic pigments are preferable.

[0030] The pigment may be dispersed using a pigment dispersant. Alternatively, the pigment may be dispersed as a self-dispersing pigment by oxidizing or sulfonating its surface with ozone, hypochlorous acid, fuming sulfuric acid, etc.

[0031] Pigment dispersants have the function of dispersing pigments in an inkjet ink composition. While pigment dispersants may be water-soluble, those that are not completely water-soluble are preferred. It is believed that they disperse the pigment by partially or completely binding to or adsorbing to the pigment, thereby increasing the hydrophilicity of the pigment surface. The type of pigment dispersant is not particularly limited.

[0032] Pigment dispersants are polymer compounds, and examples include acrylic resins and their salts such as poly(meth)acrylic acid, (meth)acrylic acid-acrylonitrile copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, vinylnaphthalene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer. In this specification, polymers having a skeleton derived from (meth)acrylic acid and not having a skeleton derived from maleic acid or a similar compound are referred to as acrylic resins.

[0033] Furthermore, examples of pigment dispersants include maleic acid-based resins and their salts, such as styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-maleic acid copolymer, and vinyl acetate-maleic acid ester copolymer; urethane-based resins and their salts, with or without crosslinking structures; polyvinyl alcohols; and resins such as vinyl acetate-crotonic acid copolymer and its salts.

[0034] Furthermore, acrylic resins may be copolymers of acrylic monomers (acrylic monomers) as described above, or copolymers of acrylic monomers with other monomers. For example, acrylic vinyl resin, which is a copolymer of vinyl monomers as the other monomer, is also called an acrylic resin. Also, among the styrene resins mentioned above, those which are copolymers of styrene monomers and acrylic monomers are included in acrylic resins. Moreover, when referring to acrylic resins, their salts and esterified products are also included.

[0035] Examples of commercially available pigment dispersants include X-200, X-1, X-205, X-220, X-228 (manufactured by Seikoh PMC), Nopcospers® 6100, 6110 (manufactured by Sunnopco Corporation), Joncryl 67, 586, 611, 678, 680, 682, 819 (manufactured by BASF), DISPERBYK-190 (manufactured by Bic Chemie Japan Co., Ltd.), N-EA137, N-EA157, N-EA167, N-EA177, N-EA197D, N-EA207D, and E-EN10 (manufactured by Daiichi Kogyo Seiyaku).

[0036] Examples of commercially available acrylic pigment dispersants include BYK-187, BYK-190, BYK-191, BYK-194N, BYK-199 (manufactured by Big Chemie Co., Ltd.), Aron A-210, A6114, AS-1100, AS-1800, A-30SL, A-7250, and CL-2 (manufactured by Toagosei Co., Ltd.).

[0037] Commercially available urethane-based pigment dispersants include BYK-182, BYK-183, BYK-184, BYK-185 (manufactured by Bic Chemi Co., Ltd.), TEGO Disperse710 (manufactured by Evonic Tego Chemi), and Borchi® Gen1350 (manufactured by OMG Borschers).

[0038] The pigment dispersant may be used alone or in combination of two or more types. The total content of the pigment dispersant is 0.1% to 30% by mass, preferably 0.5% to 25% by mass, more preferably 1% to 20% by mass, and even more preferably 1.5% to 15% by mass, based on 100% by mass of ink. By having a pigment dispersant content of 0.1% by mass or more, the dispersion stability of the pigment can be ensured. Furthermore, if the pigment dispersant content is 30% by mass or less, the viscosity of the inkjet ink composition can be kept low.

[0039] Furthermore, it is even more preferable that the weight-average molecular weight of the pigment dispersant be 500 or higher. By using such a pigment dispersant, the odor is reduced and the dispersion stability of the pigment can be further improved.

[0040] When dispersing pigments with a pigment dispersant, the ratio of pigment to pigment dispersant is preferably 10:1 to 1:10, and more preferably 4:1 to 1:3.

[0041] Furthermore, the volume-average particle diameter (D50) of the pigment, when measured by dynamic light scattering, is 20 nm to 300 nm, more preferably 30 nm to 200 nm, and even more preferably 40 nm to 100 nm.

[0042] When an inkjet ink composition contains pigment dispersed in a pigment dispersant, it is preferable that the pigment dispersant is made of an acrylic resin. This improves the dispersibility of the pigment in the inkjet ink composition.

[0043] (dye) Inkjet ink compositions may use dyes as colorants. The dyes are not particularly limited and can include acid dyes, direct dyes, reactive dyes, basic dyes, and disperse dyes. Examples of dyes include CI Acid Yellow 17, 23, 42, 44, 79, 142; CI Acid Red 52, 80, 82, 249, 254, 289; CI Acid Blue 9, 45, 249; CI Acid Black 1, 2, 24, 94; CI Food Black 1, 2; CI Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173. Examples include CI Direct Red 1, 4, 9, 80, 81, 132, 225, 227; CI Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202; CI Direct Black 19, 38, 51, 71, 154, 168, 171, 195; CI Reactive Red 14, 32, 55, 79, 141, 249; and CI Reactive Black 3, 4, 35.

[0044] Furthermore, as dyes, compounds represented by the following formula (y-1) or salts thereof,

[0045] These colorants, whether pigments or dyes, may be used individually or in combination of two or more.

[0046] The total content of colorants is preferably 0.10% to 20.0% by mass, more preferably 0.20% to 15.0% by mass, and even more preferably 1.0% to 10.0% by mass, based on the total mass (100% by mass) of the inkjet ink composition. A clear composition (clear ink) may also be used that does not contain colorants or contains colorants to an extent that is not intended for coloring (for example, 0.1% by mass or less).

[0047] 1.2. Resin The inkjet ink composition contains a resin. The resin is a polymer compound and may be in the form of resin particles that form a dispersed state in the inkjet ink composition, or it may be used in the form of a resin dissolved in the inkjet ink composition. The resin has the function of improving the adhesion, scratch resistance, etc., of the image produced by the inkjet ink composition attached to the recording medium. It is more preferable that the resin contains resin particles.

[0048] Examples of resin particles include urethane resins, acrylic resins (including styrene-acrylic resins), fluorene resins, polyolefin resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, and ethylene vinyl acetate resins. Among these, urethane resins, acrylic resins, polyolefin resins, and polyester resins are preferred. These resin particles are often handled in emulsion form, but they may also be in powder form. Furthermore, the resin particles can be used individually or in combination of two or more types.

[0049] Urethane resins are a general term for resins that contain urethane bonds. In addition to urethane bonds, urethane resins may also use polyether-type urethane resins containing ether bonds in the main chain, polyester-type urethane resins containing ester bonds in the main chain, polycarbonate-type urethane resins containing carbonate bonds in the main chain, etc. Furthermore, commercially available urethane resins may be used, such as Superflex 460, 460s, 840, E-4000 (product name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Rezamin D-1060, D-2020, D-4080, D-4200, D-6300, D-6455 (product name, manufactured by Dainichi Seika Kogyo Co., Ltd.), Takelac WS-5100, WS-6021, W-512-A-6 (product name, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), SunCure 2710 (product name, manufactured by LUBRIZOL), Permarin UA-150 (product name, manufactured by Sanyo Chemical Industries, Ltd.).

[0050] Acrylic resins are a general term for polymers obtained by polymerizing at least one acrylic monomer, such as (meth)acrylic acid or (meth)acrylic acid ester. Examples include resins obtained from acrylic monomers and copolymers of acrylic monomers with other monomers. For example, acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers, are examples. Examples of vinyl monomers include styrene.

[0051] Acrylic monomers such as acrylamide and acrylonitrile can also be used. For resin emulsions made from acrylic resins, commercially available products may be used, for example, selected from FK-854 (trade name, manufactured by Chuo Rika Kogyo Co., Ltd.), Movinyl 952B, 718A (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Nipol LX852, LX874 (trade name, manufactured by Nippon Zeon Co., Ltd.).

[0052] Styrene-acrylic resins are copolymers obtained from styrene monomers and (meth)acrylic monomers, and examples include styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymers. For the styrene-acrylic resin, commercially available products may be used, such as Joncryl 62J, 7100, 390, 711, 511, 7001, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (product names, manufactured by BASF), Movinyl 966A, 975N (product names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Vinibran 2586 (manufactured by Nisshin Chemical Industry Co., Ltd.), etc.

[0053] Polyolefin resins have olefins such as ethylene, propylene, and butylene as their structural framework, and known types can be appropriately selected and used. Commercially available olefin resins can be used, for example, Arrowbase CB-1200, CD-1200 (trade names, manufactured by Unitika Ltd.).

[0054] Furthermore, the resin particles may be supplied in the form of an emulsion. Examples of commercially available resin emulsions include Microgel E-1002, E-5002 (product names of Nippon Paint Co., Ltd., styrene-acrylic resin emulsion), Boncoat 4001 (product name of DIC Corporation, acrylic resin emulsion), Boncoat 5454 (product name of DIC Corporation, styrene-acrylic resin emulsion), Polysol AM-710, AM-920, AM-2300, AP-4735, AT-860, PSASE-4210E (acrylic resin emulsion), and Poly Polysol AP-7020 (styrene-acrylic resin emulsion), Polysol SH-502 (vinyl acetate resin emulsion), Polysol AD-13, AD-2, AD-10, AD-96, AD-17, AD-70 (ethylene-vinyl acetate resin emulsion), Polysol PSASE-6010 (ethylene-vinyl acetate resin emulsion) (product name manufactured by Showa Denko), Polysol SAE1014 (product name, styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.), Saibinol SK-200 (product name, acrylic resin emulsion, manufactured by Saiden Chemical Co., Ltd.) AE-120A (JSR product name, acrylic resin emulsion), AE373D (E-Tech product name, carboxy-modified styrene-acrylic resin emulsion), Seikadine 1900W (Dainichi Seika Kogyo product name, ethylene-vinyl acetate resin emulsion), Vinibran 2682 (acrylic resin emulsion), Vinibran 2886 (vinyl acetate-acrylic resin emulsion), Vinibran 5202 (acrylic acetate resin emulsion) (Nisshin Chemical Industry product name), Elitel KA-5071S, KT-8803, KT-9204, KT-870 1. KT-8904, KT-0507 (Unitika Corporation product names, polyester resin emulsion), Hi-Tec SN-2002 (Toho Chemical Co., Ltd. product name, polyester resin emulsion), Takelac W-6020, W-635, W-6061, W-605, W-635, W-6021 (Mitsui Chemicals Polyurethane Co., Ltd. product names, urethane resin emulsion), Superflex 870, 800, 150, 420, 460, 470, 610, 700 (Daiichi Kogyo Seiyaku Co., Ltd. product names, urethane resin emulsion), Permarin UA-150 (Sanyo Chemical Industries, Ltd.Urethane resin emulsion), SunCure 2710 (manufactured by Lubrizol Japan, urethane resin emulsion), NeoRez R-9660, R-9637, R-940 (manufactured by Kusumoto Chemical Co., Ltd., urethane resin emulsion), Adekabon Titer HUX-380, 290K (manufactured by ADEKA Corporation, urethane resin emulsion), Movinyl 966A, Movinyl 7320 (manufactured by Nippon Synthetic Chemical Co., Ltd.), Joncryl 7100, 390, 711, 511, 7001, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, P Examples include DX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (all manufactured by BASF), NK Binder R-5HN (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), Hydran WLS-210 (non-crosslinked polyurethane: manufactured by DIC Corporation), and Joncryl 7610 (manufactured by BASF).

[0055] If the resin contains resin particles, it is more preferable that the resin particles are composed of acrylic resin, polyurethane resin, or polyester resin. This makes it easier to obtain images with better nozzle clogging recovery and scratch resistance for the recording head of an inkjet recording device.

[0056] While not particularly limited, water-soluble resins include, for example, maleic acid-based resins. Maleic acid-based resins are polymer compounds having a structure derived from maleic acids. Examples of maleic acid compounds include compounds having a structure in which one carboxyl group is bonded to each of the adjacent carbon atoms connected by the carbon-carbon double bond of ethylene, as well as derivatives thereof.

[0057] Specific examples of maleic acids include maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, and mesaconic acid. Maleic acids may also be formed when the carboxyl groups bonded to adjacent carbon atoms are dehydrated or esterified. Carboxyl groups that form salts are also included in the definition of carboxyl groups.

[0058] Examples of the above derivatives include those in which the carboxyl group is derived as described above, and those in which the ethylene skeleton has further substituents.

[0059] Among the maleic acid compounds, maleic acid itself and derivatives of maleic acid in which the carboxyl group has been derived are preferred.

[0060] Maleic acid-based resins may also contain carboxyl groups derived from maleic acids that have been dehydrated or esterified. Carboxyl groups that have formed salts are also included.

[0061] Polymeric compounds having a structure derived from maleic acids can be polymeric compounds obtained by polymerization or copolymerization using at least maleic acids.

[0062] Maleic acid resins may be polymers of maleic acids or copolymers of maleic acids and other monomers. Examples of other monomers in this case include vinyl monomers such as styrene, vinylnaphthalene, and vinyl acetate, and acrylic monomers such as (meth)acrylic acid and esters of (meth)acrylic acid.

[0063] Maleic acid-based resins have a structure derived from maleic acids, and have carboxyl groups on adjacent carbon atoms or structures derived from carboxyl groups. Here, for example, when polymers of acrylic acid are polymerized by generally known methods, polymerization occurs in a so-called head-tail manner, so it is statistically rare for carboxyl groups to be positioned on adjacent carbon atoms. Therefore, compared to the polymerization of maleic acids, it is rare for carboxyl groups to be positioned adjacently on the carbon chain of the main chain in polymers of acrylic acids. This makes it possible to confirm, for example, whether the origin of adjacent carboxyl groups is derived from maleic acids by NMR (nuclear magnetic resonance spectroscopy).

[0064] The carboxyl groups of maleic acid-based resins may be esterified. For example, they may be esterified with a compound having a hydroxyl group. The two carboxyl groups of the structure derived from maleic acid may not be esterified, one may be esterified, or both may be esterified.

[0065] Furthermore, if the carboxyl group of the structure derived from maleic acid is not esterified, it may exist as a carboxylic acid in the aqueous inkjet ink composition, or it may be partially or completely neutralized with ammonia, alkanolamine, or alkylamine.

[0066] Maleic acid-based resins are water-soluble because they contain many structures derived from the carboxyl groups of maleic acid. Therefore, in water-based inkjet ink compositions, the molecular chains of maleic acid-based resins are spread out. This increases the probability that the maleic acid-based resin will encounter the flocculant when the inkjet ink composition and processing solution are mixed. As a result, maleic acid-based resins exhibit good flocculation properties, which can improve the image quality obtained using the ink set.

[0067] When one of the two carboxyl groups in the structure derived from maleic acid in maleic acid-based resins is esterified, the water resistance of the resulting image tends to improve. Conversely, when the two carboxyl groups in the structure derived from maleic acid are not esterified, the water resistance of the resulting image tends to decrease. The balance between hydrophilicity and hydrophobicity of the maleic acid-based resin can be adjusted by the degree of esterification, thereby improving the storage stability of the inkjet ink composition and further enhancing the water resistance of the resulting image. For example, styrene-maleic anhydride half-ester copolymer salt is preferred in terms of the balance between hydrophilicity and hydrophobicity. This is presumed to be because the esterified carboxyl group is highly hydrophobic, promoting insolubilization and solid-liquid separation during the reaction.

[0068] Furthermore, if a maleic acid-based resin contains structures derived from maleic anhydride, it is thought that in water, the anhydride is converted into a carboxyl group upon hydration.

[0069] Furthermore, the maleic acid-based resin is preferably a water-soluble resin and, unlike pigment dispersants, does not adsorb to pigments or other elements in the inkjet ink composition but exists as a solution dissolved in water, which is the solvent component of the ink. This results in excellent cohesiveness. The maleic acid-based resin described in this section is included in the ink separately from the pigment dispersant when the ink contains pigments dispersed by a pigment dispersant.

[0070] Maleic acid-based resins exhibit cohesive properties through the action of flocculants such as calcium propionate, as described later, depending on the resin skeleton, the number of functional groups, and the properties of the resin that constitutes their particles.

[0071] Maleic acid-based resins preferably have acidic groups such as carboxyl groups, sulfonic acid groups, and phosphoric acid groups. That is, even if carboxyl groups derived from maleic acids exist in the form of an acid or salt, or if all of the carboxyl groups derived from maleic acids are esterified, it is preferable that the skeleton or ester groups have acidic groups such as carboxyl groups, sulfonic acid groups, and phosphoric acid groups in the form of an acid or salt. Furthermore, these acidic groups may be partially or completely neutralized with ammonia, alkanolamines, or alkylamines.

[0072] The weight-average molecular weight of the maleic acid-based resin is preferably between 2,000 and 100,000, more preferably between 5,000 and 60,000, and even more preferably between 10,000 and 50,000. Within this weight-average molecular weight range, it is possible to further suppress aggregation unevenness in the resulting image and improve abrasion resistance. Discharge stability from the inkjet head is also good.

[0073] Examples of commercially available maleic acid resins include SN Dispersant 5027, 5029 (both manufactured by Sanopco Co., Ltd.), Sunspearl PS-8 (manufactured by Sanyo Chemical Industries, Ltd.), Marialim HKM-50A, 150A, AKM-0531, SC-0505K, Polystar OMA (all manufactured by NOF Corporation), Demol P, EP, ST, Boys 520, 521 (all manufactured by Kao Corporation), and Polity A550 (manufactured by Lion Corporation). Examples include Arakawa Chemical Industries, Ltd.'s own products, Alastair 703S, Polymaron 1318, 351T, 385, 372, 375CB, 482, 482S, 1329, XIRAN 1440H, 2625H, 1000H, 2000H, 3000H, Polyscope Co., Ltd., Isoban-104 (Kuraray Co., Ltd.), Floren G-700AMP, G-700DMEA (Kyoeisha Chemical Co., Ltd.), etc.

[0074] The resin content is 0.1% by mass or more and 20% by mass or less, preferably 1% by mass or more and 15% by mass or less, and more preferably 2% by mass or more and 10% by mass or less, as total solids relative to the total mass of the inkjet ink composition.

[0075] 1.3.Low molecular organic compound A The inkjet ink composition contains a water-soluble low-molecular-weight organic compound A, which is one of the amides, sulfur-containing compounds, or cyclic ethers and satisfies the following conditions (a) and (b). Condition (a) Surface tension of 10% by mass aqueous solution is 42 mN / m or more and 56 mN / m or less Condition (b) Standard boiling point is between 150°C and 300°C

[0076] The term "low molecular weight" in low molecular weight organic compound A refers to a compound with a molecular weight of 500 or less. A molecular weight of 400 or less is preferred, more preferably 300 or less, and even more preferably between 50 and 200.

[0077] Low molecular weight organic compound A is water-soluble. Water solubility means that its solubility in water at 20°C is greater than 10% by mass. For example, if the compound is mixed with water at a predetermined concentration at 20°C and stirred, and no undissolved residue is visible or the entire mixture appears cloudy, then it is considered to be soluble in water. Water solubility is defined as the minimum concentration of the compound mixed with water being greater than 10% by mass when dissolved in water. The mass percentage used to indicate solubility is the mass percentage of the low molecular weight organic compound relative to the total mass of the mixture of water and the low molecular weight organic compound.

[0078] Low molecular weight organic compound A has a surface tension of 42 mN / m to 56 mN / m in a 10% by mass aqueous solution (condition (a)) and a standard boiling point of 150°C to 300°C (condition (b)).

[0079] Regarding condition (a), the surface tension of the 10% by mass aqueous solution is as specified in condition (a), but more preferably 45 mN / m to 55 mN / m, even more preferably 46 mN / m to 54.5 mN / m, and even more preferably 47 mN / m to 54.5 mN / m. Furthermore, 50.0 to 54.5 mN / m is preferred. The surface tension can be measured at 20°C by a standard method.

[0080] When the surface tension is above the above range, the penetration of low-molecular-weight organic compound A into the recording medium can be reduced, the resin can be sufficiently dissolved, and the abrasion resistance is excellent. When the surface tension is below the above range, the ink spreads easily on the recording medium and the color development is excellent.

[0081] Regarding condition (b), the standard boiling point is as specified in condition (b), but 160°C to 290°C is more preferable, 170°C to 280°C is even more preferable, and 175°C to 276°C is even more preferable. Furthermore, 200 to 270°C is preferable, and 230 to 270°C is even more preferable.

[0082] If the standard boiling point is 300°C or lower, preferably 280°C or lower, the drying properties of the inkjet ink composition in the secondary drying process will be further improved, and its abrasion resistance will also be excellent. On the other hand, if the standard boiling point is above the above range, the evaporation of low-molecular-weight organic compound A before the resin is sufficiently dissolved on the recording medium can be reduced, resulting in excellent abrasion resistance. The standard boiling point can be measured by a standard method.

[0083] Table 1 shows an example of a specific water-soluble low-molecular-weight organic compound A that satisfies conditions (a) and (b).

[0084] [Table 1]

[0085] The inkjet ink composition may use one of the low-molecular-weight organic compounds A described above, or it may use two or more of them.

[0086] The inkjet ink composition contains low-molecular-weight organic compound A, which functions particularly well as a dissolving agent for water-dispersible resins, thus allowing the water-dispersible resin particles to swell and / or soften easily. This further improves the flatness of the surface of the formed image and enhances the scratch resistance of the image.

[0087] Amides can be any water-soluble, low-molecular-weight organic compounds that have an amide structure. Examples of amides include cyclic amides and acyclic (chain-like) amides.

[0088] Sulfur-containing compounds can be any water-soluble, low-molecular-weight organic compounds that contain a sulfur atom in their molecule. Examples of sulfur-containing compounds include sulfones and sulfoxides. The cyclic ethers can be any water-soluble, low-molecular-weight organic compounds having a cyclic ether structure. Examples include those having a cyclic ether structure with 4 to 8 membered rings. The number of oxygen atoms constituting the ring is preferably 1 to 3. Examples include oxetanes and solketals.

[0089] Selecting amides as the low-molecular-weight organic compound A is preferable because it can further improve the surface drying and fixing properties of the inkjet ink composition when it is applied to, for example, a low-absorption recording medium. Furthermore, amides tend to have excellent properties for moderately softening and dissolving vinyl chloride resins. Therefore, amides can soften and dissolve the recording surface of a recording medium containing vinyl chloride resin, allowing the inkjet ink composition to penetrate into the recording medium. As the inkjet ink composition penetrates the recording medium in this way, the components of the inkjet ink composition become firmly fixed, and the surface of the inkjet ink composition dries more easily. Consequently, the resulting image tends to have superior surface drying properties and fixing properties.

[0090] The content of low molecular weight organic compound A in the inkjet ink composition is preferably 0.5 to 15% by mass relative to the total amount of the inkjet ink composition. Furthermore, 1% to 10% by mass is preferred, 2% to 9% by mass is more preferred, 3% to 8% by mass is even more preferred, and 4% to 8% by mass is particularly preferred. Within this content range, the surface flatness of the formed image is further improved, and images with even better image quality and scratch resistance can be formed.

[0091] Low molecular weight organic compound A functions as a resin dissolving compound, and by using one with a surface tension of 42 mN / m or higher, it becomes difficult for it to penetrate the recording medium, allowing the resin to be sufficiently dissolved on the recording medium, resulting in excellent scratch resistance of the image.

[0092] 1.4. Silicone-based surfactants The inkjet ink composition contains a silicone-based surfactant that satisfies the following condition (c). Condition (c) Solubility in water at 20°C is 1% by mass or less

[0093] By containing a silicone-based surfactant that satisfies condition (c), the inkjet ink composition can improve lateral wetting (along the surface of adhesion) when attached to a recording medium, thereby forming an image with excellent color development. Silicone-based surfactants that satisfy condition (c) are thought to have relatively high hydrophobicity, making them easily wettable and spreadable on low-absorption and non-absorbent recording media.

[0094] The aforementioned low molecular weight organic compound A has a surface tension of 42 mN / m or higher in a 10% aqueous solution. Compared to cases where the surface tension of a 10% aqueous solution of the low molecular weight organic compound is lower, its penetration into the recording medium is suppressed. In this case, the low molecular weight organic compound A also tends to suppress the wetting and spreading of the ink onto the recording medium, preventing the ink from wetting and spreading. As a result, the color development of the ink tends to be inferior.

[0095] Therefore, the inkjet ink composition of this embodiment contains a silicone-based surfactant that satisfies condition (c), which allows for good wetting and spreading of the ink on the recording medium, even when the ink contains the aforementioned low-molecular-weight organic compound A, and enables the formation of an image with excellent color development.

[0096] Furthermore, if the surface tension of a 10% aqueous solution of a low-molecular-weight organic compound exceeds 56 mN / m, the wetting and spreading properties of the ink on the recording medium will be further suppressed, resulting in poor color development even if the ink contains a silicone-based surfactant that satisfies condition (c).

[0097] Therefore, by including a low-molecular-weight organic compound A and a silicone-based surfactant that satisfies condition (c), the ink can exhibit excellent abrasion resistance and color development.

[0098] Regarding condition (c), the solubility in water at 20°C is more preferably 0.8% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.2% by mass or less.

[0099] Solubility is determined as follows: First, to determine whether the solubility is 1% by mass or less at 20°C, a 1% by mass aqueous solution (silicone-based surfactant:water = 1g:99g mixture) is prepared and stirred. If it is colorless and transparent, it is determined to be dissolved, and the solubility is considered to be greater than 1% by mass. If it is semi-transparent, opaque, or contains undissolved material, it is determined to be undissolved, and the solubility is considered to be 1% by mass or less.

[0100] Table 2 shows specific examples of silicone-based surfactants that satisfy condition (c).

[0101] [Table 2]

[0102] The content of the silicone-based surfactant is preferably 0.1% to 2% by mass, more preferably 0.2% to 1% by mass, and even more preferably 0.3% to 0.8% by mass, based on the total amount of the inkjet ink composition. When the content is within this range, the nozzle clogging recovery performance is further improved, and images with even better image quality can be obtained.

[0103] Silicone-based surfactants can have their solubility in water adjusted by controlling the length of the Si chains and / or polyoxyalkylene chains in their molecular structure. For example, increasing the length of the Si chains or shortening the polyoxyalkylene chains can lower their solubility in water.

[0104] 1.5. Other ingredients 1.5.1. Anionic Surfactants The inkjet ink composition may contain an anionic surfactant represented by the following general formula (1).

[0105] [ka] (In general formula (1), R 1 and R 2 Each of the following independently represents hydrogen or a linear or branched alkyl group having 1 to 20 carbon atoms; m and n independently represent integers between 0 and 20; and M represents an atom that can form a monovalent cation.

[0106] In general formula (1), -SO3M is ionized by dissociation in the inkjet ink composition, and becomes -SO3 - , and M + It's fine if it's like that.

[0107] By containing the above-mentioned anionic surfactant in the inkjet ink composition, the affinity with the recording medium is further enhanced through a synergistic effect with the silicone-based surfactant, thereby enabling the acquisition of images with even better image quality and scratch resistance.

[0108] Specific examples of anionic surfactants include Disponil SUS IC 875 (manufactured by BASF Japan Ltd.), Sanmorin OT-70, Carabon DA-72 (manufactured by Sanyo Chemical Industries, Ltd.), Airroll CT-1 (manufactured by Toho Chemical Industry Co., Ltd.), Adekacol EC-8600 (manufactured by ADEKA Corporation), and REWOPOL SB DO 75 PG (manufactured by Evonik Japan Co., Ltd.).

[0109] When anionic surfactants are used, their content is preferably 0.05% to 1% by mass, more preferably 0.1% to 0.8% by mass, and even more preferably 0.1% to 0.5% by mass, relative to the total amount of the inkjet ink composition. Within this content range, the above effects are easily obtained.

[0110] 1.5.2.Water The inkjet ink composition is a water-based ink containing water. A water-based ink is a composition that contains water as one of its main solvent components. Water may be included as the main solvent component and is a component that evaporates upon drying. Preferably, the water is pure water or ultrapure water from which ionic impurities have been removed as much as possible, such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water. Furthermore, using water sterilized by ultraviolet irradiation or hydrogen peroxide addition is preferable because it can suppress the growth of mold and bacteria when the processing solution or inkjet ink composition is stored for a long period of time. The water content is preferably 40% by mass or more, more preferably 45% by mass or more, more preferably 50% by mass or more and 98% by mass or less, and even more preferably 55% by mass or more and 95% by mass or less, based on the total amount of the inkjet ink composition.

[0111] 1.5.3.1. Other Low Molecular Weight Organic Compounds The inkjet ink composition may contain a water-soluble, low-molecular-weight organic compound that satisfies the above-mentioned condition (b), which is an amide, sulfur-containing compound, or cyclic ether.

[0112] In other words, in addition to low molecular weight organic compound A, the mixture may also contain other water-soluble low molecular weight organic compounds that are amides, sulfur-containing compounds, or cyclic ethers, and that satisfy condition (b) but not condition (a). These are called other low molecular weight organic compounds.

[0113] In the inkjet ink composition, it is preferable that the content of the low molecular weight organic compound A (that satisfies conditions (a) and (b)) described above is 50% by mass or more, when the total mass of water-soluble low molecular weight organic compounds that satisfy the above-mentioned condition (b), which are amides, sulfur-containing compounds, or cyclic ethers, is 100% by mass.

[0114] In other words, if the ink composition contains, in addition to the low molecular weight organic compound A described above, a water-soluble low molecular weight organic compound that is one of the amides, sulfur-containing compounds, or cyclic ethers and satisfies condition (b) but not condition (a) (other low molecular weight organic compounds), it is preferable that the low molecular weight organic compound A accounts for 50% by mass or more, when the total mass including these compounds is taken as 100% by mass. Furthermore, 60% by mass or more is preferable, 70% by mass or more is more preferable, and 80% by mass or more is even more preferable. The upper limit is 100% by mass or less. In other words, it is not necessary to contain other low molecular weight organic compounds.

[0115] In other words, when the total amount of water-soluble low-molecular-weight organic compounds, which are amides, sulfur-containing compounds, or cyclic ethers, and have a standard boiling point of 150°C or higher and 300°C or lower, is taken as 100% by mass, it is preferable that the mass percentage of those compounds having a surface tension of 42 mN / m or higher and 56 mN / m or higher in a 10% by mass aqueous solution is within the above range.

[0116] In this way, the effects of the low-molecular-weight organic compound A can be fully utilized, resulting in improved nozzle clogging recovery and images with even better image quality and scratch resistance.

[0117] Other low molecular weight organic compounds include amides, sulfur-containing compounds, and cyclic ethers, which are among the organic solvents described later. Other low molecular weight organic compounds may also include those that are solid at room temperature.

[0118] 1.5.3.2. Organic Solvents The inkjet ink composition may contain an organic solvent. The organic solvent is a low-molecular-weight organic compound that is liquid at room temperature. The water-soluble low-molecular-weight organic compound A mentioned above, and other low-molecular-weight organic compounds that are liquid at room temperature, may also be organic solvents.

[0119] The organic solvent may be a water-soluble low-molecular-weight organic compound, or something other than a water-soluble low-molecular-weight organic compound. Preferably, the organic solvent is water-soluble. The functions of the organic solvent include improving the wettability of the inkjet ink composition to the recording medium and enhancing the moisture retention of the inkjet ink composition. Furthermore, the organic solvent can also function as a penetrating agent.

[0120] Examples of organic solvents include amides, sulfur-containing solvents, cyclic ethers, alkylene glycol ethers, cyclic esters, esters, and polyhydric alcohols. Among these, alkylene glycol ethers and polyhydric alcohols are preferred.

[0121] Examples of amides include cyclic amides and acyclic amides. Examples of acyclic amides include alkoxyalkyl amides. When an inkjet ink composition contains amides, the scratch resistance of the image and the wetting spread on the recording medium can be further improved. It is preferable that the organic solvent contains amides, and acyclic amides are particularly preferred.

[0122] Examples of cyclic amides include lactams, such as pyrrolidones like 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone, as well as 2-piperidone, ε-caprolactam, N-methyl-ε-caprolactam, N-cyclohexyl-2-pyrrolidone, 5-methyl-2-pyrrolidone, β-propiolactam, ω-heptalactam, and succinimide. These are preferred in terms of their solubility for flocculants and their ability to promote the film formation of resin particles, as described later, with 2-pyrrolidone and ε-caprolactam being particularly preferred.

[0123] Examples of acyclic amides include alkylamides, such as alkoxyalkylamides. Other alkylamides besides alkoxyalkylamides include alkoxyalkylamides with structures that do not contain an alkoxy group.

[0124] Examples of acyclic amides include 3-methoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, 3-methoxy-N,N-methylethylpropionamide, 3-ethoxy-N,N-dimethylpropionamide, 3-ethoxy-N,N-diethylpropionamide, 3-ethoxy-N,N-methylethylpropionamide, 3-n-butoxy-N,N-dimethylpropionamide, 3-n-butoxy-N,N-diethylpropionamide, 3-n-butoxy-N,N-methylethylpropionamide, 3-n-propoxy-N,N-dimethylpropionamide, 3-n-propoxy-N,N-diethylpropionamide, 3-n-propoxy-N,N-methylethylpropionamide, and 3-iso-propoxy- Examples include alkoxyalkylamides such as N,N-dimethylpropionamide, 3-iso-propoxy-N,N-diethylpropionamide, 3-iso-propoxy-N,N-methylethylpropionamide, 3-tert-butoxy-N,N-dimethylpropionamide, 3-tert-butoxy-N,N-diethylpropionamide, and 3-tert-butoxy-N,N-methylethylpropionamide, as well as N,N-dimethylacetacetamide, N,N-diethylacetacetamide, N,N-methylacetacetamide, N,N-dimethylisobutyrate amide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, and N,N-dimethylpropionamide.

[0125] Furthermore, it is also preferable to use compounds represented by the following general formula (2) as alkoxyalkylamides.

[0126] R 1 -O-CH2CH2-(C=O)-NR 2 R 3 ···(2)

[0127] In the above formula (2), R 1 represents an alkyl group having 1 to 4 carbon atoms, and R 2 and R 3 each independently represent a methyl group or an ethyl group. The "alkyl group having 1 to 4 carbon atoms" can be a linear or branched alkyl group, and for example, can be a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, or a tert-butyl group. The compound represented by the above formula (1) may be used alone or in combination of two or more.

[0128] As the function of the compound represented by formula (2), for example, it can enhance the surface drying property and fixing property of an inkjet ink composition adhered to a low-absorbency recording medium. In particular, the compound represented by the above formula (2) is excellent in the action of moderately softening and dissolving a vinyl chloride-based resin. Therefore, the compound represented by the above formula (2) can soften and dissolve the recording surface containing a vinyl chloride-based resin, and penetrate the inkjet ink composition into the low-absorbency recording medium. By thus allowing the inkjet ink composition to penetrate into the low-absorbency recording medium, the inkjet ink composition is firmly fixed and the surface of the inkjet ink composition is easily dried. Therefore, the obtained image is likely to be excellent in surface drying property and fixing property.

[0129] Also, in the above formula (2), R 1 is more preferably a methyl group having 1 carbon atom. In the above formula (2), the standard boiling point of the compound in which R 1 is a methyl group is lower than that of the compound in which the number of carbon atoms of R 1 is an alkyl group having 2 to 4 carbon atoms. Therefore, in the above formula (2), R 1Using compounds in which the group is a methyl group can sometimes further improve the surface drying properties of the adhesion area (especially the surface drying properties of images recorded in high-temperature and high-humidity environments).

[0130] When amides are used, their content is not particularly limited to the total mass of the inkjet ink composition, but is preferably between 2% and 50% by mass, and more preferably between 4% and 30% by mass. Being within this range may further improve image fixation and surface drying properties (especially surface drying properties when recorded in a high-temperature, high-humidity environment).

[0131] Examples of sulfur-containing compounds include sulfoxides and sulfones.

[0132] Examples of sulfoxides include acyclic sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide, and cyclic sulfoxides such as tetramethylene sulfoxide. Examples of sulfones include cyclic sulfones such as 3-methylsulfolane and sulfolane, and acyclic sulfones such as ethylisopropylsulfone, ethylmethylsulfone, and dimethylsulfone.

[0133] Examples of cyclic ethers include tetrahydrofuran, 1,4-dioxane, dimethyl isosorbide, 3-methyl-3-oxetane methanol, 3-ethyl-3-oxetane methanol, 2-hydroxymethyloxetane, tetrahydrofurfuryl alcohol, glycerol formal, solketal, 1,4-dioxane-2,3-diol, dihydrolevoglucocenone, and the like.

[0134] The alkylene glycol ethers can be any monoether or diether of alkylene glycol, with alkyl ethers being preferred. Specific examples include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether. Examples include alkylene glycol monoalkyl ethers such as ethyl ether, and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol methyl butyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether.In alkylene glycol ethers, the alkylene glycol portion preferably has 2 to 6 carbon atoms, and the ether portion preferably has 1 to 4 carbon atoms.

[0135] Furthermore, of the alkylene glycol ethers mentioned above, diethers tend to dissolve or swell the resin in the inkjet ink composition more easily than monoethers, and are therefore more preferable in that they tend to result in better scratch resistance of the formed image. On the other hand, monoethers are preferable because they may result in better wettability of the inkjet ink composition.

[0136] Examples of cyclic esters include cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, β-butyrolactone, β-valerolactone, γ-valerolactone, β-hexanolactone, γ-hexanolactone, δ-hexanolactone, β-heptanolactone, γ-heptanolactone, δ-heptanolactone, ε-heptanolactone, γ-octanolactone, δ-octanolactone, ε-octanolactone, δ-nonalactone, ε-nonalactone, and ε-decanolactone, as well as compounds in which the hydrogen atoms of the methylene group adjacent to the carbonyl group are substituted with alkyl groups having 1 to 4 carbon atoms.

[0137] Esters include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate. Examples include glycol monoacetates such as propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and methoxybutyl acetate, and glycol diesters such as ethylene glycol diacetate, diethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, diethylene glycol acetate butyrate, diethylene glycol acetate propionate, diethylene glycol acetate butyrate, propylene glycol acetate propionate, propylene glycol acetate butyrate, dipropylene glycol acetate butyrate, and dipropylene glycol acetate propionate.

[0138] Polyhydric alcohols are compounds having two or more hydroxyl groups in their molecule. Examples of polyhydric alcohols include alkane polyols, in which an alkane is substituted with two or more hydroxyl groups, and condensates, in which two or more molecules of such alkane polyols are intermolecularly condensed at the hydroxyl groups. Polyhydric alcohols with 2 to 10 carbon atoms are preferred.

[0139] Polyhydric alcohols include ethylene glycol, propylene glycol (also known as 1,2-propanediol), 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, and other 1,2-alkanediols, diethylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol (also known as 1,3-butylene glycol), 1,4-butanediol, and 1,5-phenylenediol. Examples include pentanediol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, trimethylolpropane, glycerin, etc. Polyhydric alcohols can be used individually or in mixtures of two or more.

[0140] Polyhydric alcohols can primarily function as penetrating solvents and / or moisturizing solvents. In particular, 1,2-alkanediols with 5 or more carbon atoms tend to have strong penetrating solvent properties.

[0141] When an inkjet ink composition contains an organic solvent, one type of organic solvent may be used alone, or two or more types may be used in combination. Furthermore, the total content of the organic solvent relative to the total mass of the inkjet ink composition is, for example, 5% by mass or more and 50% by mass or less, preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 25% by mass or less, and even more preferably 15% by mass or more and 25% by mass or less. Having the organic solvent content within the above range allows for better nozzle clogging recovery and the acquisition of images with better drying properties.

[0142] Furthermore, if the inkjet ink composition contains an organic solvent, it is more preferable that it contains an organic solvent among the examples above with a standard boiling point of 160.0°C to 280.0°C. This allows for faster drying and fixing of the formed image. In addition, the scratch resistance of the image, the wetting and spreading on the recording medium, and / or the drying properties of the image can be further improved.

[0143] Furthermore, it is more preferable that the inkjet ink composition does not contain more than 1.0% by mass of an organic solvent of polyhydric alcohol having a standard boiling point above 280.0°C. The content of the organic solvent of polyhydric alcohol having a standard boiling point above 280°C in the inkjet ink composition is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, particularly preferably 0.5% by mass or less, and most particularly preferably 0.1% by mass or less, based on the total mass of the inkjet ink composition. The lower limit of the content of the organic solvent of polyhydric alcohol having a standard boiling point above 280°C may be 0% by mass. When it is stated that it does not contain more than X% by mass, it means that the content is X% by mass or less, meaning that it is either not contained or contained in an amount of X% by mass or less. Note that the inkjet ink composition may optionally contain polyhydric alcohols having a standard boiling point of 280°C or higher, such as trimethylolpropane and glycerin.

[0144] This method allows for better drying of the formed image, enables faster recording, and improves adhesion to the recording medium. Furthermore, it is even more preferable that the inkjet ink composition contains an organic solvent (not limited to polyhydric alcohols) with a standard boiling point exceeding 280.0°C within the above range. Examples of organic solvents with a standard boiling point exceeding 280°C include glycerin and polyethylene glycol monomethyl ether.

[0145] Furthermore, it is more preferable that the inkjet ink composition does not contain more than 9% by mass of organic solvents among the above-mentioned organic solvents, the organic solvent having a surface tension of 35 mN / m or less in a 10% by mass aqueous solution. This allows for the formation of images with even better color development.

[0146] 1.5.4. Surfactants The inkjet ink composition may contain surfactants other than the silicone-based surfactants and anionic surfactants described above. Surfactants have the function of reducing the surface tension of the inkjet ink composition and improving wettability with the recording medium or substrate. Among surfactants, acetylene glycol-based surfactants, silicone-based surfactants that do not satisfy the above condition (c), and fluorine-based surfactants can be preferably used.

[0147] Acetylene glycol-based surfactants are not particularly limited, but examples include Surfinol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, DF-110D, CT111, CT121, CT131, CT136, TG, GA, DF110D (all of the above are brand names, Air Products & Chemicals). Examples include (manufactured by Nisshin Chemical Industry Co., Ltd.), Olfin B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP.4001, EXP.4036, EXP.4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all product names, manufactured by Nisshin Chemical Industry Co., Ltd.), and Acetyleneol E00, E00P, E40, E100 (all product names, manufactured by Kawaken Fine Chemical Co., Ltd.).

[0148] As silicone-based surfactants that do not satisfy the above condition (c), polysiloxane compounds are preferred, although they are not particularly limited. As polysiloxane compounds, polyether-modified organosiloxanes are preferred, although they are not particularly limited. Examples of commercially available polyether-modified organosiloxanes include BYK-306, BYK-307, BYK-3331, BYK-333, BYK-341, BYK-345, BYK-348, BYK-346, BYK-348, BYK-349, BYK-3420, BYK-3480, BYK-3481 (all trade names, manufactured by Bic Chemie Japan), KF-351A, and KF-352A. Examples include KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (all product names, manufactured by Shin-Etsu Chemical Co., Ltd.), SAG003, SAG502, SAG503A, SAG008 (all product names, manufactured by Nisshin Chemical Co., Ltd.), TEGO WET 260, TEGO WET 280, TEGO WET KL245 (all product names, manufactured by Evonik Japan), and DOWSIL 502W (product name, manufactured by Dow Toray Industries, Inc.).

[0149] As fluorine-based surfactants, it is preferable to use fluorine-modified polymers. Specific examples include BYK-3440 (manufactured by Bic Chemie Japan), Surflon S-241, S-242, S-243 (all trade names, manufactured by AGC Seimi Chemical Co., Ltd.), and Futergent 215M (manufactured by Neos Co., Ltd.).

[0150] When an inkjet ink composition contains surfactants, multiple types may be included. The amount of surfactants contained in the inkjet ink composition is preferably 0.1% to 2.0% by mass, more preferably 0.2% to 1.5% by mass, and more preferably 0.3% to 1.0% by mass, based on the total mass.

[0151] 1.5.5. Additives The inkjet ink composition may contain additives such as ureas, amines, and sugars. Examples of ureas include urea, ethylene urea, tetramethylurea, thiourea, 1,3-dimethyl-2-imidazolidinone, and betaines (trimethylglycine, triethylglycine, tripropylglycine, triisopropylglycine, N,N,N-trimethylalanine, N,N,N-triethylalanine, N,N,N-triisopropylalanine, N,N,N-trimethylmethylalanine, carnitine, acetylcarnitine, etc.).

[0152] The amines include monoethanolamine, diethanolamine, triethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-aminoethylethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-tert-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, N-tert-butyldiethanolamine, 2-amino-1-propanol, and 2-amino-2-methyl-1-propanol. Examples of alkanolamines include 5-amino-1-pentanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-methylamino-1,2-propanediol, propanolamine, N,N-dimethylpropanolamine, N,N-diethylpropanolamine, trippropanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, N,N-dimethylisopropanolamine, and N,N-diethylisopropanolamine. Ureas and amines may also function as pH adjusters.

[0153] Examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0154] 1.5.6. Others The inkjet ink composition may further contain, as needed, preservatives, fungicides, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, and mold inhibitors.

[0155] 1.6. Manufacturing and physical properties of inkjet ink compositions The viscosity of the inkjet ink composition at 20°C is preferably 2 mPa·s to 15 mPa·s. When the viscosity of the inkjet ink composition at 20°C is within this range, it becomes even more suitable for the inkjet method, the inkjet ink composition is ejected more appropriately from the nozzle, and flight deviation and scattering of the inkjet ink composition can be further reduced, making it even more suitable for use in inkjet recording devices.

[0156] Inkjet ink compositions are obtained by mixing the above-mentioned components in an appropriate order and removing impurities by filtration or other means as necessary. A preferred method for mixing the components is to add the materials to a container equipped with a stirring device such as a mechanical stirrer or magnetic stirrer and then stir-fry them.

[0157] 1.7. Applications of inkjet ink compositions The inkjet ink composition of this embodiment is more preferably used for recording on low-absorption or non-absorption recording media. The inkjet ink composition can produce images with good image quality and scratch resistance even on low-absorption or non-absorption recording media.

[0158] 1.8. Effects According to the inkjet ink composition of this embodiment, as the low molecular weight organic compound A satisfies conditions (a) and (b), it is possible to obtain an image with good nozzle clogging recovery, as well as good image quality and scratch resistance.

[0159] In other words, in the inkjet ink composition of this embodiment, if the surface tension of the low molecular weight organic compound A is low enough that it does not satisfy condition (a), wetting and spreading properties can be obtained on the recording medium, but at the same time, penetration in the thickness direction of the recording medium also increases. Therefore, the surface tension is set to satisfy condition (a) to suppress penetration. The inkjet ink composition contains a silicone-based surfactant that satisfies condition (c) to compensate for the wetting and spreading properties on the recording medium.

[0160] On the other hand, in the inkjet ink composition of this embodiment, if the surface tension of the low molecular weight organic compound A is too high to satisfy condition (a), the wettability on the recording medium will be insufficient even if a silicone-based surfactant that satisfies condition (c) is used. Therefore, an upper limit is set for condition (a). In other words, in the inkjet ink composition of this embodiment, the low molecular weight organic compound A is used with a surface tension within a predetermined range that is neither too high nor too low, and by using this with the above-mentioned specific silicone surfactant, both excellent color development and abrasion resistance are achieved.

[0161] 2. Recording Method The recording method according to this embodiment includes an ink deposition step of depositing the above-described inkjet ink composition onto a recording medium by an inkjet method.

[0162] 2.1 Recording media The recording medium on which an image is formed using the recording method according to this embodiment may have a recording surface that absorbs liquids such as inkjet ink compositions, or it may not have a recording surface that absorbs liquids. Therefore, there are no particular restrictions on the recording medium, and examples include liquid-absorbing recording media such as paper and cloth, low-liquid-absorbent recording media such as printing paper, and non-liquid-absorbent recording media such as metals, glass, films, and polymers. However, the excellent effects of the recording method of this embodiment become more pronounced when recording an image on a low-liquid-absorbent or non-liquid-absorbent recording medium. That is, according to the recording method of this embodiment, even with low-absorbent or non-absorbent recording media that are relatively prone to aggregation unevenness, it is possible to form high-quality images with good scratch resistance.

[0163] A liquid-low absorption or liquid-non-absorbent recording medium refers to a recording medium that does not absorb liquid at all or absorbs very little liquid. Quantitatively, a liquid-non-absorbent or liquid-low absorption recording medium is defined as "a recording medium that absorbs liquid at all or very little liquid from the start of contact in the Bristow method for 30 msec." 1 / 2 Up to 10 mL / m² of water absorption capacity 2 This refers to the recording media described below. The Bristow method is the most widely used method for measuring liquid absorption in a short time and is also adopted by the Japan Pulp and Paper Technology Association (JAPAN TAPPI). Details of the test method are described in standard No. 51 "Paper and cardboard - Liquid absorbency test method - Bristow method" of the "JAPAN TAPPI Pulp and Paper Test Methods 2000 Edition". In contrast, a liquid absorbent recording media refers to a recording media that does not fall under liquid non-absorbent or liquid low absorbency. In this specification, liquid low absorbency and liquid non-absorbency may be simply referred to as low absorbency and non-absorbency.

[0164] Examples of liquid-non-absorbent recording media include films and plates of plastics such as polyvinyl chloride, polyethylene, polypropylene, and polyethylene terephthalate (PET); plates of metals such as iron, silver, copper, and aluminum; metal plates or plastic films manufactured by vapor deposition of these metals; and alloy plates such as stainless steel and brass. Other examples include materials on which plastic is coated onto a substrate such as paper, materials on which a plastic film is bonded to a substrate such as paper, and plastic films that do not have an absorbent layer (receiving layer). Examples of plastics used here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

[0165] Furthermore, examples of low-liquid-absorption recording media include recording media having a coating layer (receiving layer) on the surface for receiving liquid. For example, printing paper is an example of a recording media with a paper substrate, and plastic film is an example of a recording media with a hydrophilic polymer or the like coated on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc., or a recording media with silica, titanium, or other particles coated together with a binder.

[0166] While not particularly limited, examples of liquid-absorbing recording media include plain paper such as electrophotographic paper with high liquid permeability, inkjet paper (inkjet-specific paper equipped with an ink-absorbing layer composed of silica particles or alumina particles, or an ink-absorbing layer composed of hydrophilic polymers such as polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP)), and art paper, coated paper, and cast paper used in general offset printing, which have relatively low liquid permeability. Furthermore, fabrics and nonwoven fabrics can also be given as examples of liquid-absorbing recording media.

[0167] The recording medium may be colorless and transparent, semi-transparent, colored and transparent, chromatic and opaque, achromatic and opaque, etc. Furthermore, the recording medium itself may be colored, semi-transparent, or transparent.

[0168] 2.2. Ink Application Process The ink application process can be carried out in any manner as long as the inkjet ink composition is applied while the recording head and the recording medium are scanned relative to each other. For example, it is preferable to use an inkjet method in which the recording head is an inkjet head and the inkjet ink composition is ejected from the inkjet head. In this way, small-volume, multi-type printing can be efficiently performed with a small device. In addition to the inkjet method, ink application may also be carried out using analog printing methods or other methods.

[0169] The ink application process can be easily performed using an inkjet recording device. Details of the inkjet recording device will be described later. A composition used for recording by ejecting ink from an inkjet head using the inkjet method is called an inkjet ink composition.

[0170] According to the recording method of this embodiment, since the above-mentioned inkjet ink composition is used, images with good image quality and scratch resistance can be obtained.

[0171] The ink application process may be performed when the surface temperature of the recording medium is 50°C or lower. That is, the ink application process may be performed without heating the recording medium, or with heating, and if heating is performed, the recording medium's surface temperature should be 50°C or lower. In this way, images with good image quality and scratch resistance can be obtained with better drying properties. The ink application process may also be performed with cooling as needed.

[0172] 2.3. Other processes The recording method may include a processing liquid application step, a heating step, a lamination step, and so on.

[0173] 2.3.1. Processing liquid application process The processing solution application process involves applying the processing solution to the recording medium. Methods for applying the processing solution to the recording medium include non-contact and contact methods, such as inkjet printing, coating, applying the processing solution to the recording medium using various sprays, immersing the recording medium in the processing solution, and applying the processing solution to the recording medium with a brush or the like, or a combination thereof.

[0174] The processing solution application step may be performed using an inkjet recording device. This is preferable because the processing solution and inkjet ink composition can be applied to the recording medium using a single inkjet recording device. The processing solution will be described below, and details of the inkjet recording device will be described later.

[0175] (Processing solution) The treatment solution contains a coagulant. The individual components contained in the treatment solution are described below.

[0176] (Flocculant) The processing solution contains a flocculant that aggregates the components of the inkjet ink composition. The inkjet ink composition described above exhibits excellent flocculation of resins and colorants by the flocculant in the processing solution, and can produce images with excellent image quality.

[0177] A coagulant has the function of coagulating at least one of the dispersions of components such as resins, pigments, and water-dispersible resins contained in an inkjet ink composition by acting on their dispersibility. The degree of coagulation of the dispersion by the coagulant varies depending on the type of coagulant and the target, and can be adjusted. This coagulation action can, for example, enhance the color development of the image and / or improve the fixation of the image.

[0178] While not particularly limited, examples of flocculants include metal salts, acids, and cationic compounds. Cationic compounds include cationic resins (cationic polymers) and cationic surfactants. Among these, polyvalent metal salts are preferred as metal salts, and cationic resins are preferred as cationic compounds. Among acids, organic acids and inorganic acids are preferred, with organic acids being preferred. Therefore, selecting a flocculant from cationic resins, organic acids, and polyvalent metal salts is preferable in terms of obtaining particularly excellent image quality, scratch resistance, gloss, etc.

[0179] While polyvalent metal salts are preferred as the metal salts, other metal salts can also be used. Among these flocculants, it is preferable to use at least one selected from metal salts and organic acids because of its excellent reactivity with the components contained in the ink. Furthermore, among cationic compounds, it is preferable to use cationic resins because they dissolve easily in the treatment solution. It is also possible to use multiple types of flocculants in combination.

[0180] A polyvalent metal salt is a compound composed of a metal ion with two or more valencies and an anion. Examples of metal ions with two or more valencies include calcium, magnesium, copper, nickel, zinc, barium, aluminum, titanium, strontium, chromium, cobalt, and iron. Among the metal ions that make up these polyvalent metal salts, it is preferable that at least one of calcium ions and magnesium ions is present, given their excellent ability to aggregate the components of the ink.

[0181] The anions constituting the polyvalent metal salt are inorganic ions or organic ions. In other words, the polyvalent metal salt in this invention consists of an inorganic ion or organic ion and a polyvalent metal. Examples of such inorganic ions include chloride ions, bromide ions, iodide ions, nitrate ions, sulfate ions, hydroxide ions, etc. Examples of organic ions include organic acid ions, such as carboxylate ions.

[0182] Furthermore, the polyvalent metal compound is preferably an ionic polyvalent metal salt, and in particular, the stability of the treatment solution is better when the polyvalent metal salt is a magnesium salt or a calcium salt. In addition, either an inorganic acid ion or an organic acid ion may be used as the counterion for the polyvalent metal.

[0183] Specific examples of the polyvalent metal salts mentioned above include calcium carbonate (heavy calcium carbonate and light calcium carbonate), calcium nitrate, calcium chloride, calcium sulfate, magnesium sulfate, calcium hydroxide, magnesium chloride, magnesium carbonate, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, magnesium silicate, copper nitrate, calcium acetate, magnesium acetate, aluminum acetate, calcium propionate, magnesium propionate, aluminum propionate, calcium lactate, magnesium lactate, and aluminum lactate. These polyvalent metal salts may be used individually or in combination of two or more. Among these, at least one of magnesium sulfate, calcium nitrate, aluminum lactate, and calcium propionate is preferred in that it provides sufficient solubility in water. These metal salts may also contain water of hydration in their raw material form.

[0184] Examples of metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts, such as sodium sulfate and potassium sulfate.

[0185] Suitable organic acids include, for example, poly(meth)acrylic acid, formic acid, acetic acid, propionic acid, glycolic acid, oxalic acid, malonic acid, malic acid, maleic acid, ascorbic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, citric acid, tartaric acid, lactic acid, pyruvate, pyrrolidone carboxylic acid, pyrrone carboxylic acid, pyrrole carboxylic acid, furanic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, or derivatives of these compounds, or salts thereof. Organic acids may be used individually or in combination of two or more. Salts of organic acids that are metal salts are included in the above-mentioned metal salts.

[0186] Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. Inorganic acids may be used individually or in combination of two or more.

[0187] Examples of cationic resins (cationic polymers) include cationic urethane resins, cationic olefin resins, cationic amine resins, and cationic surfactants.

[0188] As cationic urethane resins, commercially available products can be used, such as Hydran CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, CP-7610 (product names, manufactured by Dainippon Ink and Chemicals, Inc.), Superflex 600, 610, 620, 630, 640, 650 (product names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and Urethane Emulsion WBR-2120C, WBR-2122C (product names, manufactured by Taisei Fine Chemical Co., Ltd.).

[0189] Cationic olefin resins have olefins such as ethylene and propylene as their structural framework, and known ones can be appropriately selected and used. Cationic olefin resins may also be in an emulsion state dispersed in a solvent such as water or an organic solvent. Commercially available cationic olefin resins can be used, such as Arrowbase CB-1200 and CD-1200 (trade names, manufactured by Unitika Ltd.).

[0190] As cationic amine resins (cationic polymers), any resin having an amino group in its structure is acceptable, and known resins can be appropriately selected and used. Examples include polyamine resins, polyamide resins, and polyallylamine resins. Polyamine resins are resins having an amino group in the main skeleton of the resin. Polyamide resins are resins having an amide group in the main skeleton of the resin. Polyallylamine resins are resins having a structure derived from an allyl group in the main skeleton of the resin.

[0191] Furthermore, examples of cationic polyamine resins include Unisense KHE103L (hexamethylenediamine / epichlorohydrin resin, 1% aqueous solution with a pH of approximately 5.0, viscosity of 20-50 (mPa·s), and solid content of 50% by mass) and Unisense KHE104L (dimethylamine / epichlorohydrin resin, 1% aqueous solution with a pH of approximately 7.0, viscosity of 1-10 (mPa·s), and solid content of 20% by mass) manufactured by Senka Co., Ltd. Furthermore, specific examples of commercially available cationic polyamine resins include FL-14 (manufactured by SNF), Arafix 100, 251S, 255, 255LOX (manufactured by Arakawa Chemical Co., Ltd.), DK-6810, 6853, 6885; WS-4010, 4011, 4020, 4024, 4027, 4030 (manufactured by Seikou PMC Co., Ltd.), and Papiogen P-105 (manufactured by Senka Co., Ltd.). Examples include Sumirez Resin 650(30), 675A, 6615, SLX-1 (manufactured by Taoka Chemical Industry Co., Ltd.), Kachiomaster (registered trademark) PD-1, 7, 30, A, PDT-2, PE-10, PE-30, DT-EH, EPA-SK01, TMHMDA-E (manufactured by Yokkaichi Gosei Co., Ltd.), and Jetfix 36N, 38A, 5052 (manufactured by Satoda Chemical Co., Ltd.).

[0192] Examples of polyallylamine resins include polyallylamine hydrochloride, polyallylamineamide sulfate, allylamine hydrochloride / diallylamine hydrochloride copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine hydrochloride / dimethylallylamine hydrochloride copolymer, allylamine / dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamineamide sulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate / sulfur dioxide copolymer, diallylmethylethylammonium ethyl sulfate / sulfur dioxide copolymer, methyldiallylamine hydrochloride / sulfur dioxide copolymer, diallyldimethylammonium chloride / sulfur dioxide copolymer, and diallyldimethylammonium chloride / acrylamide copolymer.

[0193] Examples of cationic surfactants include primary, secondary, and tertiary amine salt compounds, alkylamine salts, dialkylamine salts, aliphatic amine salts, benzalkonium salts, quaternary ammonium salts, quaternary alkylammonium salts, alkylpyridinium salts, sulfonium salts, phosphonium salts, onium salts, and imidazolinium salts. Specifically, examples include hydrochlorides and acetates of laurylamine, coconutamine, rosinamine, etc., lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, dimethylethyl laurylammonium ethyl sulfate, dimethylethyl octylammonium ethyl sulfate, trimethyllaurylammonium hydrochloride, cetylpyridinium chloride, cetylpyridinium bromide, dihydroxyethyl laurylamine, decyldimethylbenzylammonium chloride, dodecyldimethylbenzylammonium chloride, tetradecyldimethylammonium chloride, hexadecyldimethylammonium chloride, and octadecyldimethylammonium chloride. Furthermore, cationic surfactants function as flocculants as described later, but they may also be included in the inkjet ink composition. However, it is more preferable that the cationic surfactant be included as a flocculant in the processing solution.

[0194] Multiple types of these flocculants may be used. Furthermore, selecting at least one of these flocculants—a polyvalent metal salt, an organic acid, or a cationic resin—results in better flocculation, thus enabling the formation of higher-quality images (especially those with good color reproduction).

[0195] The total content of the flocculant in the processing solution is preferably 0.1% to 20% by mass, more preferably 1% to 20% by mass, and more preferably 2% to 15% by mass, relative to the total mass of the processing solution. Even when the flocculant is shared in a solution or dispersion, it is preferable that the solid content is within the above range. If the flocculant content is 1% by mass or more, the ability of the flocculant to flocculate the components contained in the ink is sufficiently obtained. Furthermore, if the flocculant content is 30% by mass or less, the solubility and dispersibility of the flocculant in the processing solution are improved, and the storage stability of the processing solution can be improved.

[0196] Furthermore, even if the organic solvent contained in the treatment solution has high hydrophobicity, the solubility of the coagulant in the treatment solution will be good. Therefore, it is preferable to use a coagulant that has a solubility of 1 g or more in 100 g of water at 25°C, and more preferably one that is 3 g or more and 80 g or less.

[0197] (Other ingredients) The processing solution may contain, in addition to the flocculant, water-soluble low-molecular-weight organic compounds, organic solvents, surfactants, water, waxes, additives, preservatives / fungal agents, rust inhibitors, chelating agents, antioxidants, and fungicides, as long as they do not impair its function. Since these components are the same as those in the inkjet ink composition described above, a detailed explanation is omitted. A water-based processing solution is preferred.

[0198] The processing solution may contain the aforementioned low-molecular-weight organic compound A. In this case, it is preferable as it provides superior scratch resistance and image quality.

[0199] Furthermore, the processing solution may contain a silicone-based surfactant that satisfies the aforementioned condition (c). In this case, abrasion resistance and image quality are preferable. The content of low molecular weight organic compound A and the silicone-based surfactant that satisfies condition (c) may be the same as those for the ink described above.

[0200] The processed liquid is obtained by mixing the above-mentioned components in an appropriate order and removing impurities by filtration or other means as necessary. A preferred method for mixing the components is to add the materials to a container equipped with a stirring device such as a mechanical stirrer or magnetic stirrer and then stir-fry them.

[0201] If the recording method includes a processing liquid application step in which a processing liquid containing a coagulant is applied to the recording medium, an image with even better image quality can be obtained. It is preferable that the processing liquid application step be performed before the ink application step. In this way, the coagulant contained in the processing liquid can act sufficiently on the inkjet ink composition. Furthermore, the recording method of this embodiment may include a step of applying one or more of the processing liquid and inkjet ink compositions to the recording medium as needed. There are no restrictions on the order or number of these steps, and they can be performed as appropriate as needed. In this case, the processing liquid and each inkjet ink composition may or may not be applied to the same area on the recording medium. According to the recording method of this embodiment, an image with high image quality and good scratch resistance can be formed.

[0202] 2.3.2.Heating process (Primary heating process) The ink application step of the recording method in this embodiment may include a heating step for heating the composition attached to the recording medium. This allows for a more pronounced effect of obtaining high-quality images with good scratch resistance and high recording speed. Such a heating step is called a primary heating step. The primary heating step involves rapidly heating and drying the inkjet ink composition (ink) attached to the recording medium. This heating evaporates at least a portion of the solvent component of the ink composition attached to the recording medium. Ink is applied to the heated recording medium, or the recording medium is heated shortly after the ink has been applied to it, with heating beginning approximately 1 second after the ink droplet is attached to the recording medium.

[0203] The primary heating step may include a step of heating the recording medium before or during the processing liquid application step and / or ink application step. The primary heating step can be carried out by means of drying using a heating mechanism. Means of drying using a heating mechanism include means of blowing room temperature air or hot air onto the recording medium (air blower type), means of irradiating the recording medium with heat-generating radiation (infrared rays, etc.) (radiation type), a member that contacts the recording medium and transfers heat to the recording medium (conduction type), and combinations of two or more of these means. If there is a primary heating step, it is more preferable to carry it out by the radiation type. The primary heating step using a heating mechanism immediately promotes the drying of the composition attached to the recording medium.

[0204] The primary heating step is preferably carried out by a heating mechanism positioned immediately before or immediately after each composition adheres to the surface, as described later. This suppresses heating of the inkjet head, resulting in improved clogging resistance and enhanced ejection stability.

[0205] The surface temperature of the recording medium during ink adhesion in the inkjet ink composition adhesion process is preferably 50°C or lower, more preferably 45.0°C or lower, even more preferably 43.0°C or lower, even more preferably 40.0°C or lower, even more preferably 38.0°C or lower, particularly preferably 35.0°C or lower, even more preferably 32.0°C or lower, even more preferably 30.0°C or lower, and particularly preferably 28.0°C or lower. On the other hand, the lower limit is preferably 20.0°C or higher, more preferably 23.0°C or higher, even more preferably 25.0°C or higher, particularly preferably 28.0°C or higher, even more preferably 30.0°C or higher, and even more preferably 32.0°C or higher.

[0206] When performing the primary heating step, the surface temperature of the recording medium due to primary heating is preferably within the above range. In particular, 28.0°C or higher is preferred.

[0207] This temperature is the surface temperature of the portion of the recording surface of the recording medium that has received the composition during the adhesion process, and is the highest temperature in the recording area during the adhesion process. A surface temperature below the above range is more preferable in terms of reduced clogging and high gloss. A temperature above the above range is more preferable in terms of image durability and good composition spread, resulting in superior image quality.

[0208] The surface temperature of the recording medium during adhesion can be made relatively high by performing a primary heating process using a heating mechanism, or relatively low by omitting this process.

[0209] If the primary heating step is performed, it can be carried out simultaneously with one or more of the adhesion steps described above. When the primary heating step is carried out simultaneously with the adhesion step, the surface temperature of the recording medium is preferably 43.0°C or lower, and more preferably 40.0°C or lower.

[0210] In the recording method of this embodiment, if a primary heating step is included in which the inkjet ink composition attached to the recording medium is heated, an image with good image quality and scratch resistance can be obtained with even better drying properties.

[0211] (Post-heating process) The inkjet recording method according to this embodiment may include a post-heating step in which the recording medium is further heated after the primary heating step following each of the above adhesion steps. The post-heating step is also called a secondary heating step. In the post-heating step, heating begins approximately 1 second or more after all the ink to be adhered to a certain area of ​​the recording medium has adhered.

[0212] The post-heating process can be carried out using an appropriate heating means. For example, the post-heating process is performed using an after-heater (in the example of the inkjet recording device 1 described later, this corresponds to heating heater 5). Furthermore, the heating means is not limited to the heating means provided in the inkjet recording device; other drying means may also be used. This dries the resulting image and allows it to be fixed more thoroughly, so for example, the recorded material can be made usable sooner.

[0213] The temperature of the recording medium in this case is not particularly limited, but can be set considering, for example, the Tg of the resin components constituting the resin particles contained in the recording material. When considering the Tg of the resin components constituting water-dispersible resins or waxes, it is preferable to set the temperature to 5.0°C or higher, preferably 10.0°C or higher, than the Tg of the resin components.

[0214] The surface temperature of the recording medium reached by the post-heating step is 30.0°C to 120.0°C, preferably 40.0°C to 100.0°C, more preferably 50.0°C to 95°C, and even more preferably 70°C to 90°C. The surface temperature of the recording medium reached by the post-heating step is particularly preferably 80°C or higher. When the temperature of the recording medium is within this range, the resin particles contained in the recording material can be film-formed and flattened, and the resulting image can be dried and fixed more sufficiently.

[0215] 2.3.3. Lamination Process The recorded material obtained by the recording method may be used after lamination of the recording surface. The lamination process for laminating to a recording medium can be carried out by laminating a film onto the recording surface of a recording medium to which an inkjet ink composition has been attached. Alternatively, although not particularly limited, a known adhesive may be attached to the recording surface of the recorded material and a film may be attached to it, or a film with adhesive attached may be attached to the recording surface of the recorded material. In addition, a molten resin in which the film has been melted can be used to extrude the molten resin onto the recording surface of the recorded material and form it as a film on the recording surface of the recorded material. As the material for the film used for lamination, for example, a resin film can be used. Laminating the recorded material is preferable because it improves the abrasion resistance of the recorded material and provides superior protection against excessive handling, such as when the recorded material comes into contact with solid objects. Furthermore, after the recorded material and the film have been bonded together, it is preferable to further heat or press at room temperature to ensure sufficient adhesion.

[0216] 3. Inkjet recording device An example of an inkjet recording apparatus suitable for the recording method according to this embodiment will be described with reference to the drawings. The inkjet recording apparatus includes an inkjet head that performs an ink application process of an inkjet ink composition and a primary heating mechanism. The above-described recording method can be performed with this apparatus.

[0217] Figure 1 is a schematic cross-sectional view illustrating an inkjet recording device. Figure 2 is a perspective view showing an example of the configuration around the carriage of the inkjet recording device 1 in Figure 1. As shown in Figures 1 and 2, the inkjet recording device 1 comprises an inkjet head 2, an IR heater 3, a platen heater 4, a heating heater 5, a cooling fan 6, a preheater 7, a ventilation fan 8, a carriage 9, a platen 11, a carriage movement mechanism 13, a transport means 14, and a control unit CONT. The operation of the entire inkjet recording device 1 is controlled by the control unit CONT shown in Figure 2.

[0218] The inkjet head 2 is configured to record on the recording medium M by ejecting a processing liquid and an inkjet ink composition from the nozzles of the inkjet head 2 and adhering them to the recording medium M. In this embodiment, the inkjet head 2 is a serial inkjet head, and it adheres ink to the recording medium M by scanning it multiple times in the main scanning direction relative to the recording medium M. The inkjet head 2 is mounted on a carriage 9 shown in Figure 2. The inkjet head 2 is scanned multiple times in the main scanning direction relative to the recording medium M by the operation of a carriage movement mechanism 13 that moves the carriage 9 in the media width direction of the recording medium M. The media width direction is the main scanning direction of the inkjet head 2. Scanning in the main scanning direction is also called main scanning.

[0219] Here, the main scanning direction is the direction in which the carriage 9, on which the inkjet head 2 is mounted, moves. In Figure 1, this is the direction that intersects with the sub-scanning direction, which is the transport direction of the recording medium M indicated by arrow SS. In Figure 2, the width direction of the recording medium M, i.e., the direction represented by S1-S2, is the main scanning direction MS, and the direction represented by T1→T2 is the sub-scanning direction SS. Note that in one scan, scanning is performed in the main scanning direction, i.e., in either the direction of arrow S1 or arrow S2. Then, by repeating the main scan of the inkjet head 2 and the sub-scan, which is the transport of the recording medium M, multiple times, data is recorded on the recording medium M. In other words, the processing liquid adhesion process and the ink adhesion process are performed by multiple main scans in which the inkjet head 2 moves in the main scanning direction, and multiple sub-scans in which the recording medium M moves in the sub-scanning direction that intersects with the main scanning direction.

[0220] The cartridge 12, which supplies the inkjet ink composition and processing liquid to the inkjet head 2, comprises a plurality of independent cartridges. The cartridge 12 is detachably mounted on the carriage 9 on which the inkjet head 2 is mounted. Each of the plurality of cartridges is filled with a different type of inkjet ink composition and processing liquid, and the inkjet ink composition and processing liquid are supplied from the cartridge 12 to each nozzle. In this embodiment, the example shown is that the cartridge 12 is mounted on the carriage 9, but it is not limited to this, and may be provided in a location other than the carriage 9 and supplied to each nozzle by a supply pipe (not shown).

[0221] Conventional known methods can be used for ejection from the inkjet head 2. In this embodiment, a method is used that ejects droplets using the vibration of a piezoelectric element, that is, an ejection method that forms ink droplets by the mechanical deformation of an electrostrictive element.

[0222] The inkjet recording device 1 is equipped with an IR heater 3 and a platen heater 4 for heating the recording medium M when the inkjet ink composition is ejected from the inkjet head 2. A primary heating step can be performed using either the IR heater 3 or the platen heater 4. Furthermore, in this embodiment, when drying the recording medium M in the primary heating step, a ventilation fan 8 or the like, described later, can be used.

[0223] Furthermore, by using the IR heater 3, the recording medium M can be heated radiantly by infrared radiation from the inkjet head 2 side. This makes it easier for the inkjet head 2 to be heated at the same time, but the temperature can be raised without being affected by the thickness of the recording medium M, compared to when the recording medium M is heated from the back side by a platen heater 4 or the like. In addition, various fans (e.g., ventilation fan 8) may be provided to dry the ink on the recording medium M by blowing warm air or air at the same temperature as the environment onto the recording medium M.

[0224] The platen heater 4 can heat the recording medium M via the platen 11 at a position opposite the inkjet head 2, so that the processing liquid and inkjet ink composition ejected by the inkjet head 2 can dry quickly from the moment they adhere to the recording medium M. The platen heater 4 can heat the recording medium M by conduction, and in the recording method of this embodiment, the inkjet ink composition can be attached to the recording medium M that has been heated in this way (primary heating). Therefore, the inkjet ink composition can be fixed on the recording medium M early, and the image quality can be improved.

[0225] The heating element 5 is a heater for secondary heating or secondary drying, which dries and solidifies the processing liquid and inkjet ink composition attached to the recording medium M. The heating element 5 can be used in a post-heating step. When the heating element 5 heats the recording medium M on which the image is recorded, moisture and other substances contained in the inkjet ink composition evaporate more quickly and are scattered, and an ink film is formed by the resin contained in the inkjet ink composition. In this way, the ink film is firmly fixed or adhered to the recording medium M, resulting in excellent film-forming properties, and a high-quality image can be obtained in a short time.

[0226] The inkjet recording device 1 may have a cooling fan 6. After the inkjet ink composition recorded on the recording medium M is dried, the inkjet ink composition on the recording medium M is cooled by the cooling fan 6, thereby forming an ink coating film with good adhesion on the recording medium M.

[0227] Furthermore, the inkjet recording device 1 may be equipped with a preheater 7 to preheat the recording medium M before the inkjet ink composition is applied to the recording medium M. In addition, the inkjet recording device 1 may be equipped with a ventilation fan 8 to allow the inkjet ink composition applied to the recording medium M to dry more efficiently.

[0228] Below the carriage 9 are a platen 11 that supports the recording medium M, a carriage movement mechanism 13 that moves the carriage 9 relative to the recording medium M, and a transport means 14 which is a roller that transports the recording medium M in the sub-scanning direction. The operation of the carriage movement mechanism 13 and the transport means 14 is controlled by the control unit CONT.

[0229] Figure 3 is a functional block diagram of the inkjet recording device 1. The control unit CONT is a control unit for controlling the inkjet recording device 1. The interface unit 101 (I / F) is for sending and receiving data between the computer 130 (COMP) and the inkjet recording device 1. The CPU 102 is an arithmetic processing unit for controlling the entire inkjet recording device 1. The memory 103 (MEM) is for reserving an area for storing the CPU 102's program and a work area. The CPU 102 controls each unit by the unit control circuit 104 (UCTRL). The detector group 121 (DS) monitors the status inside the inkjet recording device 1, and the control unit CONT controls each unit based on the detection results.

[0230] The transport unit 111 (CONVU) controls the sub-scanning (transport) of inkjet recording, and specifically controls the transport direction and transport speed of the recording medium M. Specifically, it controls the transport direction and transport speed of the recording medium M by controlling the rotation direction and rotation speed of the transport rollers driven by the motor.

[0231] The carriage unit 112 (CARU) controls the main scan (pass) of inkjet recording, and specifically moves the inkjet head 2 back and forth in the main scan direction. The carriage unit 112 comprises a carriage 9 on which the inkjet head 2 is mounted, and a carriage movement mechanism 13 for moving the carriage 9 back and forth.

[0232] The head unit 113 (HU) controls the amount of inkjet ink composition ejected from the nozzles of the inkjet head 2. For example, if the nozzles of the inkjet head 2 are driven by piezoelectric elements, the head unit 113 controls the operation of the piezoelectric elements in each nozzle. The head unit 113 controls the timing of each ink deposition, the dot size of the inkjet ink composition, and so on. Furthermore, the amount of inkjet ink composition deposited per scan is controlled by a combination of the control of the carriage unit 112 and the head unit 113.

[0233] The drying unit 114 (DU) controls the temperatures of various heaters, including the IR heater 3, preheater 7, platen heater 4, and heating heater 5.

[0234] The inkjet recording device 1 described above alternately repeats the operation of moving the carriage 9, on which the inkjet head 2 is mounted, in the main scanning direction and the transport operation (sub-scanning). At this time, the control unit CONT controls the carriage unit 112 to move the inkjet head 2 in the main scanning direction when performing each pass, and controls the head unit 113 to eject droplets of inkjet ink composition from predetermined nozzle holes of the inkjet head 2, thereby adhering droplets of inkjet ink composition to the recording medium M. The control unit CONT also controls the transport unit 111 to transport the recording medium M in the transport direction at a predetermined transport amount (feed amount) during the transport operation.

[0235] In the inkjet recording device 1, the recording area to which multiple droplets have been attached is gradually transported by repeating the main scan (pass) and sub-scan (transport operation). Then, the after heater 5 dries the droplets attached to the recording medium M, and the image is completed. After that, the completed recording may be wound into a roll by a winding mechanism or transported by a flatbed mechanism.

[0236] Figure 4 is an example of a flowchart showing the processes performed when recording in an inkjet recording device. When recording is started, the control unit of the inkjet recording device determines the recording mode in step 400. The recording mode is a recording method in which details of the recording are defined, such as the nozzle arrangement, ejection amount, overlapping method, operation of the inkjet head during recording, operation of the recording medium, and control of the heating mechanism. The recording details also include the number of recording passes (the number of times the main scan is performed on the same recording area of ​​the recording medium).

[0237] The recording mode is determined by input signals from an external device such as a computer to the inkjet recording device, or by user input information to the user input section of the inkjet recording device. Here, the input signals from the external device or the user input information may be information that directly specifies the recording mode, or it may be recording-related information such as information on the type of recording medium to be recorded, the recording speed specification, or the image quality specification. Furthermore, the recording-related information is not limited to these. In the latter case, the inkjet recording device stores correspondence information in the control unit or other parts of the inkjet recording device that pre-defines the recording mode corresponding to the recording-related information, and determines the recording mode by referring to the correspondence information. Alternatively, it may be determined using AI technology (artificial intelligence technology).

[0238] In step S401, the determined recording mode is identified. In step S402 or S403, the number of passes corresponding to the determined recording mode is set. In step S404, recording is performed. In the diagram, two types of recording modes are shown: the first recording mode and the second recording mode, but there may be three or more.

[0239] In this example, the recording device is preferable because it can perform a variety of recordings by varying the number of recording passes (the number of times the main scan is performed on the same recording area of ​​the recording medium) depending on the recording mode.

[0240] The inkjet recording apparatus illustrated above allows for the suitability of applying the recording method of this embodiment.

[0241] 4. Examples The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" below refers to mass.

[0242] 4.1. Preparation of Pigment Dispersions 50 g of methyl ethyl ketone (MEK) was added to a flask equipped with a dropping funnel, nitrogen inlet, reflux condenser, thermometer, and stirrer, and heated to 75°C while bubbling with nitrogen. A mixture of monomers consisting of 80 g of butyl methacrylate, 50 g of methyl methacrylate, 15 g of styrene, and 20 g of methacrylic acid, along with 50 g of MEK and 500 mg of polymerization initiator (azobisisobutyronitrile / AIBN), was added dropwise through the dropping funnel over 3 hours. After addition, the mixture was heated under reflux for a further 6 hours, and after cooling, the volatile MEK was added to obtain a resin solution (50% by mass of resin solids, acid value 79 mg / KOH, Tg 65°C). A predetermined amount of 20% by mass of sodium hydroxide aqueous solution was added to 20 g of this solution as a neutralizing agent to completely neutralize the salt-forming groups, and then 50 g of pigment (carbon black) was gradually added while stirring, and the mixture was kneaded in a bead mill for 2 hours. 200 g of deionized water was added to the resulting mixture and stirred. The mixture was then heated under reduced pressure, and MEK was removed by distillation. The concentration was further adjusted with deionized water to obtain a pigment dispersion (20% by mass of pigment solids, 5% by weight of resin solids).

[0243] 4.2 Preparation of inkjet ink composition Each component was placed in a container to obtain the compositions shown in Tables 3 and 4. The mixture was then stirred with a magnetic stirrer for 2 hours, and then filtered through a membrane filter with a pore size of 5 μm to obtain the inkjet ink compositions (inks A to X) according to the examples and comparative examples.

[0244] [Table 3]

[0245] [Table 4]

[0246] The abbreviations used in Tables 3 and 4 are as follows: • CPL: ε-caprolactam, standard boiling point 267°C (mixed surface tension 54.1) (cyclic amides) • MSF: 3-methylsulfolane, standard boiling point 276°C (mixed surface tension 51.7) (contains sulfur) • EOXM: 3-ethyl-3-oxetanemethanol, standard boiling point 220°C (mixed surface tension 47.8) (cyclic ethers) • 2P: 2-pyrrolidone, standard boiling point 245°C (mixed surface tension 60.2) (cyclic amides) CHP:N-cyclohexyl-2-pyrrolidone, standard boiling point 290°C (mixed surface tension 40.8) (cyclic amides) • DMPA: 3-Methoxy-N,N-dimethylpropanamide, standard boiling point 215°C (mixed surface tension 57.8) (chain amides) • DMSO: Dimethyl sulfoxide, standard boiling point 189°C (mixed surface tension 68.0) (contains sulfur) • DMIS: Dimethyl isosorbide, standard boiling point 240°C (mixed surface tension 58.0) (cyclic ethers) • 1,2BD: 1,2-butanediol, standard boiling point 192°C (mixed surface tension 51.3) (alkanediols) • 1,2HD: 1,2-Hexanediol, standard boiling point 224°C (mixed surface tension 26.9) (Alkanediols) • PG: Propylene glycol, standard boiling point 188°C (mixed surface tension 61.2) (alkanediols) TIPA: Triisopropanolamine, standard boiling point 301°C (mixed surface tension 45.4) (alkanolamines) • Joncryl 631: Styrene-acrylic resin emulsion, manufactured by BASF Japan Ltd. • Hi-Tec E-6500: Polyethylene-based wax emulsion, manufactured by Toho Chemical Industry Co., Ltd. · BYK-3420: Silicone surfactant (solubility 0.1 - 0.5%), manufactured by BYK Chemie Japan Co., Ltd. · BYK-3480: Silicone surfactant (solubility less than 0.1%), manufactured by BYK Chemie Japan Co., Ltd. · BYK-348: Silicone surfactant (solubility over 1%), manufactured by BYK Chemie Japan Co., Ltd. · Disponil SUS IC 875: Anionic surfactant according to general formula (1), manufactured by BASF Japan Ltd. · Surfynol DF110D: Acetylene glycol surfactant (antifoaming agent), manufactured by Nitto Kagaku Kogyo Co., Ltd.

[0247] The mixed surface tension is the value (mN / m) measured by preparing a 10% by mass aqueous solution of each low molecular organic compound or organic solvent as the test solution and, for example, using an automatic surface tension meter CBVP-Z (trade name, manufactured by Kyowa Interface Science Co., Ltd.) to confirm the surface tension when the platinum plate is wetted with ink under an environment of 20°C.

[0248] 4.3. Preparation of treatment liquid Each component was put into a container so as to have the composition shown in Table 5, mixed and stirred with a magnetic stirrer for 2 hours, and then filtered through a membrane filter with a pore size of 5 μm to obtain treatment liquids (treatment liquids A to C).

[0249]

Table 5

[0250] The abbreviations, etc. in Table 5 are as follows. · Cation Master PD-7: Amine·epichlorohydrin-based cationic resin. Manufactured by Yokkaichi Gosei Co., Ltd. Note that dicarboxylic acid is classified as an organic acid. For the others, refer to the footnotes in Tables 3 and 4.

[0251] 4.4. Evaluation method 4.4.1. Recording test Recordings of each example and each comparative example were created under the following recording conditions. (Printing Conditions) · Printer: Modified SC-R5050 manufactured by Seiko Epson Corporation · Resolution: 1200×1200 dpi · Application amount: 18 mg / inch of ink composition 2 , 2 mg / inch of treatment liquid 2 · Printing pattern: Solid pattern (black single color (color ink)) · Scanning times: 9 times · Platen heating temperature (primary heating): As described in Table 6 · Post-drying temperature (secondary heating): 80°C · Recording medium: 3686, Trisolv Poster Paper (manufactured by Seal, coated paper) · Platen gap: 1.7 mm

[0252] The nozzles of the head of the above printer were filled with ink and treatment liquid for recording. In the example using the treatment liquid, the ink and the treatment liquid were discharged and adhered in the same main scanning area in the same main scanning.

[0253] 4.4.2. Evaluation of Image Quality (Color Development) Under the conditions of the recording test, the recording medium was set and a solid pattern was printed. The OD value was measured with a colorimeter i1 iO2 (manufactured by X-Rite). (The light source used was D50.) The evaluation was carried out according to the following criteria, and the results are shown in Table 6. AA: OD value is 2.1 or more A: OD value is 2.0 or more and less than 2.1 B: OD value is 1.8 or more and less than 2.0 C: OD value is less than 1.8

[0254] 4.4.3. Evaluation of Image Quality (Aggregation Unevenness) Under the conditions of the recording test, the recording medium was set, a solid pattern was printed, and the printed matter was visually observed. The evaluation was carried out according to the following criteria, and the results are shown in Table 6. AA: No aggregation unevenness (uniform) A: Some aggregation unevenness is visible but there is no problem B: Aggregation unevenness is prominent but acceptable C: Uneven aggregation is noticeable. Furthermore, the edges of the recording pattern are not straight, and ink is overflowing. Furthermore, aggregation unevenness refers to the appearance of uneven ink color within a solid color pattern.

[0255] 4.4.4. Evaluation of abrasion resistance Under the conditions of the recording test, a solid pattern was printed on the recording medium, left at room temperature for 30 minutes, and the printed area was cut into a 30 x 150 mm rectangle. The degree of ink peeling was visually evaluated after rubbing it 100 times using a JSPS-type abrasion resistance tester (load 500 g) with a plain woven cloth. The evaluation was performed according to the following criteria, and the results are shown in Table 6. AA: No peeling A: Less than 20% of the assessed area is peeling. B: Less than 50% of the assessed area is peeling. C: More than 50% of the evaluated area is peeling.

[0256] 4.4.5. Evaluation of clogging recovery ability Under the recording test conditions, non-emission was intentionally induced in the nozzles. In this state, the machine was run for 3 hours without ink at the platen temperature conditions shown in Table 6. After recording, cleaning was performed three times, and the number of nozzle failures in the ink row was evaluated. Each cleaning involved ejecting 0.5g of ink from the nozzle row. Non-emission was induced by tapping the nozzle surface with a water-moistened velvet. The nozzle row consisted of 400 nozzles. The processing solution was not included in the evaluation. The evaluation was performed according to the following criteria, and the results are shown in Table 6. AA: No nozzle failure to dispense A: Nozzle non-discharge rate is less than 1% B: Nozzle non-discharge rate: 1% or more but less than 3% C: Nozzle non-discharge rate of 3% or more

[0257] 4.4.6. Evaluation of storage stability For each ink composition, 30g was sealed in an aluminum pack to prevent air bubbles from being introduced, and then left in a 60°C constant temperature bath for 6 days. After removal and natural cooling, the samples were subjected to a shear rate of 200s using a rheometer (MCR702 / Anton Paar). -1The viscosity was measured, and the thickening rate was calculated by comparing it with the initial viscosity (immediately after ink preparation). Evaluation was performed according to the following criteria, and the results are shown in Tables 3 and 4. A: Thickening rate less than 3% B: Thickening rate of 3% or more and less than 5% C: Thickening rate of 5% or more

[0258]

Table 6

[0259] 4.5. Evaluation Results Each inkjet ink composition of the aqueous ink containing a colorant, a resin, a water-soluble low molecular weight organic compound A which is any one of amides, sulfur-containing compounds, and cyclic ethers and satisfies conditions (a) and (b), and a silicone surfactant which satisfies condition (c) was found to be excellent in both the abrasion resistance of the image and the image quality. On the other hand, in the comparative examples where it was not so, the abrasion resistance or the image quality of the image was poor in all cases.

[0260] The above-described embodiments and modifications are examples, and are not limited thereto. For example, it is also possible to appropriately combine each embodiment and each modification.

[0261] The present invention includes a configuration substantially the same as the configuration described in the embodiments, for example, a configuration having the same functions, methods, and results, or a configuration having the same objects and effects. Further, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiments is replaced. Further, the present invention includes a configuration having the same operational effects as the configuration described in the embodiments or a configuration capable of achieving the same object. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiments.

[0262] The following contents are derived from the above-described embodiments and modifications.

[0263] The inkjet ink composition a colorant, a resin, A water-soluble low-molecular-weight organic compound A, which is an amide, sulfur-containing compound, or cyclic ether and satisfies the following conditions (a) and (b), A silicone-based surfactant that satisfies the following condition (c), It is a water-based ink containing [ingredient]. Condition (a) Surface tension of 10% by mass aqueous solution is 42 mN / m or more and 56 mN / m or less Condition (b) Standard boiling point is between 150°C and 300°C Condition (c) Solubility in water at 20°C is 1% by mass or less

[0264] According to this inkjet ink composition, as the low molecular weight organic compound A satisfies conditions (a) and (b), it is possible to obtain an image with good nozzle clogging recovery, as well as good image quality and scratch resistance.

[0265] In the above inkjet ink composition, The content of the low molecular weight organic compound A may be 1% by mass or more and 10% by mass or less based on the total amount of the inkjet ink composition.

[0266] This inkjet ink composition allows for the production of images with improved nozzle clogging recovery, as well as better image quality and scratch resistance.

[0267] In the above inkjet ink composition, The aqueous solution does not need to contain more than 9% by mass of an organic solvent with a surface tension of 35 mN / m or less.

[0268] This inkjet ink composition allows for the formation of images with even better color reproduction.

[0269] In the above inkjet ink composition, The content of the silicone-based surfactant may be 0.1% by mass or more and 2% by mass or less based on the total amount of the inkjet ink composition.

[0270] This inkjet ink composition allows for the production of images with improved nozzle clogging recovery, as well as better image quality and scratch resistance.

[0271] In the above inkjet ink composition, The aforementioned resin contains resin particles, The resin particles may be composed of any of acrylic resin, polyurethane resin, or polyester resin.

[0272] This inkjet ink composition allows for the production of images with improved nozzle clogging recovery and scratch resistance.

[0273] In the above inkjet ink composition, The total content of the organic solvent may be 5% by mass or more and 30% by mass or less based on the total amount of the inkjet ink composition.

[0274] This inkjet ink composition allows for the creation of images with improved nozzle clogging recovery and good drying properties.

[0275] In the above inkjet ink composition, When the total mass of water-soluble low molecular weight organic compounds that satisfy condition (b) and are any of the amides, sulfur-containing compounds, or cyclic ethers contained in the inkjet ink composition is taken as 100% by mass, the content of the low molecular weight organic compound A may be 80% by mass or more.

[0276] This inkjet ink composition allows for the production of images with improved nozzle clogging recovery, as well as better image quality and scratch resistance.

[0277] In the above inkjet ink composition, It may be used for recording on low absorption recording media or non-absorption recording media.

[0278] This inkjet ink composition makes it possible to obtain images with good image quality and scratch resistance even on low-absorption or non-absorption recording media.

[0279] In the above inkjet ink composition, The following general formula (1) may be used to describe an anionic surfactant.

[0280] [ka] (In general formula (1), R 1 and R 2 Each of the following independently represents hydrogen or a linear or branched alkyl group having 1 to 20 carbon atoms; m and n independently represent integers between 0 and 20; and M represents an atom that can form a monovalent cation.

[0281] This inkjet ink composition, due to the synergistic effect of the anionic surfactant and the silicone-based surfactant, increases affinity with the recording medium, resulting in images with even better image quality and scratch resistance.

[0282] The recording method is: The system includes an ink deposition step in which the above-mentioned inkjet ink composition is deposited onto a recording medium by an inkjet method.

[0283] This recording method allows for the acquisition of images with good image quality and scratch resistance.

[0284] In the above recording method, The ink application process may be performed when the surface temperature of the recording medium is 50°C or lower.

[0285] This recording method allows for the acquisition of images with good image quality and scratch resistance, as well as improved drying properties.

[0286] In the above recording method, The system may also include a primary heating step for heating the inkjet ink composition adhering to the recording medium.

[0287] This recording method allows for the acquisition of images with good image quality and scratch resistance, as well as improved drying properties.

[0288] In the above recording method, The process may include a step of applying a processing solution containing a coagulant to the recording medium.

[0289] This recording method allows for the acquisition of images with even better image quality. [Explanation of Symbols]

[0290] 1... Inkjet recording device, 2... Inkjet head, 2a... Nozzle surface, 3... IR heater, 4... Platen heater, 5... Heating heater, 6... Cooling fan, 7... Preheater, 8... Ventilation fan, 9... Carriage, 11... Platen, 12... Cartridge, 13... Carriage movement mechanism, 14... Transport means, 101... Interface unit, 102... CPU, 103... Memory, 104... Unit control circuit, 111... Transport unit, 112... Carriage unit, 113... Head unit, 114... Drying unit, 121... Detector group, 130... Computer, CONT... Control unit, MS... Main scanning direction, SS... Sub-scanning direction, M... Recording medium

Claims

1. Colorants, resin, A water-soluble, low-molecular-weight organic compound A, which is an amide and satisfies the following conditions (a) and (b), A silicone-based surfactant that satisfies the following condition (c), It contains, The 10% by mass aqueous solution does not contain more than 9% by mass of an organic solvent with a surface tension of 35 mN / m or less. It is used for recording on low absorption recording media or non-absorption recording media. The aforementioned resin contains resin particles, The aforementioned resin particles are resin particles composed of one of the following: acrylic resin, polyurethane resin, or polyester resin. A water-based inkjet ink composition. Condition (a) Surface tension of 10% by mass aqueous solution is 42 mN / m or more and 56 mN / m or less Condition (b) Standard boiling point is between 150°C and 300°C Condition (c) Solubility in water at 20°C is 1% by mass or less

2. In claim 1, An inkjet ink composition in which the content of the low molecular weight organic compound A is 1% by mass or more and 10% by mass or less based on the total amount of the inkjet ink composition.

3. In any one of claims 1 to 2, An inkjet ink composition in which the content of the silicone-based surfactant is 0.1% by mass or more and 2% by mass or less based on the total amount of the inkjet ink composition.

4. In any one of claims 1 to 3, An inkjet ink composition in which the content of the resin particles is 1 to 15% by mass relative to the total mass of the inkjet ink composition.

5. In any one of claims 1 to 4, An inkjet ink composition in which the total content of organic solvents is 5% by mass or more and 30% by mass or less based on the total amount of the inkjet ink composition.

6. In any one of claims 1 to 5, An inkjet ink composition in which, when the total mass of water-soluble low molecular weight organic compounds that satisfy condition (b) and are any of amides, sulfur-containing compounds, or cyclic ethers contained in the inkjet ink composition is taken as 100% by mass, the content of the low molecular weight organic compound A is 80% by mass or more.

7. In any one of claims 1 to 6, An inkjet ink composition used for recording on non-absorbent recording media.

8. Colorants, resin, A water-soluble low-molecular-weight organic compound A, which is an amide, sulfur-containing compound, or cyclic ether and satisfies the following conditions (a) and (b), A silicone-based surfactant that satisfies the following condition (c), An anionic surfactant represented by the following general formula (1), An inkjet ink composition which is a water-based ink containing [the specified ingredient]. Condition (a) Surface tension of 10% by mass aqueous solution is 42 mN / m or more and 56 mN / m or less Condition (b) Standard boiling point is between 150°C and 300°C Condition (c) Solubility in water at 20°C is 1% by mass or less 【Chemistry 1】 (In general formula (1), R 1 and R 2 Each of the following independently represents hydrogen or a linear or branched alkyl group having 1 to 20 carbon atoms; m and n independently represent integers between 0 and 20; and M represents an atom that can form a monovalent cation.

9. A recording method comprising an ink deposition step of depositing an inkjet ink composition according to any one of claims 1 to 8 onto a recording medium by an inkjet method.

10. In claim 9, The aforementioned ink application step is performed when the surface temperature of the recording medium is 50°C or lower, in a recording method.

11. In claim 9 or claim 10, A recording method comprising a primary heating step of heating the inkjet ink composition adhering to the recording medium.

12. In any one of claims 9 to 11, A recording method comprising a process step of applying a processing liquid containing a coagulant to the recording medium.

Images