Recording method and recording device

Abstract

To provide a recording method capable of achieving both recording of an image with excellent image quality and excellent printing speed.SOLUTION: A recording method for recording in a recording medium according to the present invention includes: a white ink adhesion step of adhering a white ink composition containing a white coloring material to the recording medium; and a non-white ink adhesion step of adhering a non-white ink composition containing a non-white coloring material to the recording medium. The white ink adhesion step and the non-white ink adhesion step are performed by the relative scanning of a recording head and the recording medium. The white ink adhesion step and the non-white ink adhesion step are performed by the same relative scanning in the same scanning area of the recording medium. In a recording area to which the white ink composition and the non-white ink composition are adhered, an amount of adhesion of the white ink composition is 60 mass% or less based on 100 mass% of an amount of adhesion of the non-white ink composition per unit area.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a recording method and a recording apparatus. [Background technology]

[0002] In recent years, recording (printing) on ​​product labels and the like for flexible packaging films such as PET films has been considered. Flexible packaging films are also used for packaging foods and the like, and in such applications, the recording surface of the flexible packaging film is made of a plastic material such as polyolefin, nylon, polyester, etc., and a transparent or semi-transparent material is often used so that the contents can be confirmed.

[0003] Additionally, in recent years, the use of printing for the production of so-called sign graphics, such as billboards, window graphics, and car wrapping, is expanding. In sign graphics, a wide range of materials are used as recording media, including banners, coated paper, matte paper, wallpaper, cloth, and plastic films such as PET and PVC. Among these, the use of billboards, which are printed on transparent or semi-transparent plastic films and then attached to windows, etc., has recently been expanding rapidly.

[0004] Furthermore, label printing is also done, which is also done on transparent or semi-transparent plastic film. In textile printing, printing is done on non-transparent but non-white fabric. In these various printing methods, printing is done on transparent recording media and non-transparent but non-white recording media.

[0005] In these various printing processes, when printing on a transparent medium or when recording on an opaque medium that is non-white, in order to record an image with excellent visibility, a predetermined image may be formed using a color ink composition on a layer formed using a white ink, which is called a base layer and which conceals the background.

[0006] For example, Patent Document 1 describes an image recording method in which a base layer (white ink layer) is recorded on a recording medium using a white ink composition, and a color image layer (color ink layer) is recorded on the base layer using a color ink composition. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2010-158884 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, while a recording method using a lamination method in which a white ink layer is used as a background image for color ink layers can record images with excellent visibility (images with excellent image quality), it has the problem of slow printing speed due to the process of laminating each ink layer. Therefore, there is a demand for both recording images with excellent image quality and excellent printing speed. [Means for solving the problem]

[0009] One aspect of the recording method according to the present invention is to A recording method for recording on a recording medium, comprising the steps of: a white ink applying step of applying a white ink composition containing a white color material to the recording medium; A non-white ink application process for applying a non-white ink composition containing a non-white coloring material to the recording medium. With the procedure and the white ink depositing step and the non-white ink depositing step are performed by scanning a recording head and the recording medium relative to each other; the white ink depositing step and the non-white ink depositing step are performed on the same scanning area of ​​the recording medium by the same relative scanning, In the recording area to which the white ink composition and the non-white ink composition are applied, the amount of the white ink composition applied is 60% by mass or less relative to 100% by mass of the non-white ink composition applied per unit area.

[0010] One aspect of the recording device according to the present invention is A recording device for recording on a recording medium, a white ink head that deposits a white ink composition containing a white coloring material onto the recording medium; a non-white ink head that deposits a non-white ink composition containing a non-white colorant onto the recording medium; a scanning mechanism for scanning the ink head and the recording medium relative to each other; Recording is performed by the recording method of the above aspect. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram of an example of a recording apparatus used in the recording method according to the embodiment. [Diagram 2] FIG. 2 is a schematic diagram of the periphery of a carriage in an example of a printing apparatus used in a printing method according to an embodiment. [Diagram 3] 5A and 5B are schematic diagrams showing the positions of the nozzle array in each pass and the printing area at those positions. [Figure 4] FIG. 2 is a schematic plan view showing an example of an arrangement of nozzle rows in a print head of an example of a printing apparatus used in a printing method according to an embodiment. [Diagram 5] FIG. 2 is a block diagram of an example of a recording apparatus used in the recording method according to the embodiment. [Figure 6] FIG. 11 is a schematic plan view showing another example of the arrangement of ejection nozzle rows in a print head of an example of a printing apparatus used in a printing method according to an embodiment. [Figure 7] FIG. 11 is a schematic plan view showing another example of the arrangement of nozzle rows in the print head of an example of a printing apparatus used in a printing method according to an embodiment. [Figure 8] 5 is a flowchart showing an example of processing performed when recording is performed by a recording device used in the recording method according to the embodiment. [Figure 9] FIG. 1 is a schematic side view showing a part of a recording apparatus that performs recording by a lateral scan method. [Figure 10] FIG. 1 is a schematic overhead view showing a part of a recording apparatus that performs recording by a lateral scan method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described. The embodiment described below is an example of the present invention. The present invention is not limited to the following embodiment, and includes various modified forms that are implemented within the scope that does not change the gist of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0013] 1. Recording method A recording method according to one embodiment of the present invention is a recording method for recording on a recording medium, comprising: a white ink applying step of applying a white ink composition containing a white coloring material to the recording medium; and a non-white ink applying step of applying a non-white ink composition containing a non-white coloring material to the recording medium, the white ink applying step and the non-white ink applying step being performed by relative scanning of a recording head and the recording medium, the white ink applying step and the non-white ink applying step being performed on the same scanned area of ​​the recording medium by the same relative scanning, and in the recording area to which the white ink composition and the non-white ink composition have been applied, a non-white ink composition having a non-white coloring material is applied to the recording medium with respect to an applied amount of the non-white ink composition per unit area of ​​100% by mass. The amount of adhesion is 60 mass % or less.

[0014] In other words, the recording method according to this embodiment involves depositing a white ink composition and a non-white ink composition in the same scanning area on a recording medium in the same relative scan by a recording head, and specifying the amount of deposited white ink composition relative to the amount of deposited non-white ink composition.

[0015] When a white ink composition and a non-white ink composition are applied to the same scanning area on a recording medium by a recording head in the same relative scan, the process of laminating each ink layer is not performed, which is advantageous in terms of printing speed. However, in such a recording method, the white ink composition and the non-white ink composition may be mixed on the recording medium, resulting in a whitish image. In addition, when directly printing on a colored or transparent medium, it is generally assumed that a method of improving visibility is to conceal the background, that is, to form a base layer with a white ink. Therefore, in the conventional technology, the idea of ​​applying both ink compositions to the same scanning area on a recording medium in the same relative scan was not reached, and the recording head also had a configuration in which each ink layer was laminated. In contrast, the recording method according to the present embodiment is a new discovery that even when both ink compositions are applied to the same scanning area on a recording medium by the same relative scan, it is possible to form an image with good color development, excellent visibility, and excellent image quality. This is presumably because the white ink composition and the non-white ink composition are applied at a specific application ratio, which makes it possible to obtain high shielding properties of the ink layer due to the white colorant while maintaining excellent image quality. Therefore, the recording method according to this embodiment can achieve both excellent image quality and excellent printing speed.

[0016] In the following, the recording method according to the present embodiment will first be described with reference to the recording medium, and then each step will be described.

[0017] 1.1. Recording medium The recording medium on which an image is formed by the recording device according to this embodiment may have a recording surface that absorbs liquid such as ink, or may not have a recording surface that absorbs liquid. Therefore, the recording medium is not particularly limited, and examples thereof include absorbent recording media such as paper, ink-absorbent film, and cloth, low-absorbent recording media such as printing paper, and non-absorbent recording media such as metal, glass, and polymer.

[0018] The excellent effect of the recording method of this embodiment is more remarkable and preferable when recording an image on a low-absorption recording medium or a non-absorption recording medium.

[0019] A low-absorption recording medium or a non-absorption recording medium refers to a recording medium that does not absorb any liquid such as ink or absorbs very little of it. Quantitatively, a low-absorption recording medium or a non-absorption recording medium is one that "is capable of absorbing ink within 30 msec from the start of contact in the Bristow method." 1 / 2 Water absorption up to 10mL / m 2 This refers to a recording medium that is "absorbent or less than 100%." ​​The Bristow method is the most widely used method for measuring the amount of liquid absorbed in a short period of time, and is also adopted by the Japan Pulp and Paper Technical Association (JAPAN TAPPI). Details of the test method are described in Standard No. 51 "Paper and paperboard - Liquid absorbency test method - Bristow method" of the "JAPAN TAPPI Paper and Pulp Test Method 2000 Edition." In contrast, liquid absorbent recording media refers to recording media that do not fall under the category of low absorbency recording media or non-absorbency recording media.

[0020] Examples of non-absorbent recording media include those in which a plastic is coated on a substrate such as paper, those in which a plastic film is adhered to a substrate such as paper, and plastic films that do not have an absorbent layer (receptive layer). The plastics referred to here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, Examples of the material include polyurethane, polyethylene, and polypropylene.

[0021] Further, examples of low-absorption recording media include recording media having a coating layer (receptive layer) on the surface for receiving liquids such as ink. For example, recording media having a paper substrate include printing paper such as art paper, coated paper, and matte paper. When the substrate is a plastic film, examples include those having a hydrophilic polymer or the like coated on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, or the like, and those having particles of silica, titanium, or the like coated together with a binder.

[0022] The recording medium may be a non-white recording medium such as colorless transparent, semi-transparent, colored transparent, or chromatic opaque, or a white recording medium such as achromatic opaque. A non-white recording medium is a recording medium having a color other than white, or a recording medium having transparency (semi-transparent or transparent). Examples of colors other than white include, but are not limited to, black and brown.

[0023] Even with such a recording medium, the recording method according to the present embodiment can perform recording that achieves both excellent image quality and excellent printing speed. Therefore, the recording method according to the present embodiment can suitably use a non-white recording medium as the recording medium.

[0024] Furthermore, when the recording medium is colorless and transparent, the recorded matter recorded by the recording method according to the present embodiment has the advantage that the image appears the same when viewed from the side of the recording medium on which the image is formed and when viewed from the opposite side. For example, when the recorded matter is attached to a window, the image quality is excellent when viewed from both the outside and the inside of the window.

[0025] 1.2. White ink application process The recording method according to this embodiment includes a white ink applying step of applying a white ink composition containing a white color material to a recording medium.

[0026] 1.2.1. White ink composition The white ink composition used in the recording method according to this embodiment contains a white colorant. Each component contained in the white ink composition will be described below.

[0027] 1.2.1.1.White color material Examples of the white coloring material include metal compounds such as metal oxides, barium sulfate, and calcium carbonate. Examples of the metal oxides include titanium dioxide, zinc oxide, silica, alumina, and magnesium oxide. In addition, the white coloring material may be particles having a hollow structure, and known particles having a hollow structure may be used.

[0028] Among the above-listed white coloring materials, titanium dioxide is preferably used as the white coloring material from the viewpoint of good whiteness and abrasion resistance. The white coloring material may be used alone or in combination of two or more kinds.

[0029] The volume-based average particle diameter (D50) of the white coloring material (also referred to as "volume average particle diameter") is preferably 30.0 nm or more and 600.0 nm or less, more preferably 100.0 nm or more and 500.0 nm or less, and even more preferably 150.0 nm or more and 400.0 nm or less. If the volume average particle diameter of the white coloring material is within the above range, the particles are less likely to settle, the dispersion stability can be improved, and when applied to a recording device, clogging of nozzles and the like can be prevented. In addition, if the volume average particle diameter of the white coloring material is within the above range, the color density such as whiteness can be fully satisfied.

[0030] The volume average particle size of the white colorant can be measured by a particle size distribution measuring device that uses the laser diffraction scattering method as its measurement principle. Examples of particle size distribution measuring devices include a particle size distribution meter that uses the dynamic light scattering method as its measurement principle (e.g., "Microtrack UPA" manufactured by Nikkiso Co., Ltd.).

[0031] In this specification, the term "white" when referring to a white ink composition, a white coloring material, etc. does not only refer to a completely white color, but also includes chromatic or achromatic colors and glossy colors as long as they are visible as white. Examples of white ink compositions include those that are sold under names that suggest that the ink is white. More quantitatively, "white" can be expressed as, for example, L * Not only colors with L = 100, *is between 80 and 100, and a * and b * The above-mentioned ranges are also included for colors where the difference is within ±10. More preferably, the difference is within ±5. More specifically, the color ink is applied to a transparent recording medium in a sufficient amount, and the applied area is measured in reflection mode with a colorimeter conforming to CIELAB. A sufficient amount of application is, for example, 15 mg / inch. 2 An ink in which the above formula is satisfied is referred to as a white ink composition. A colorant that makes the ink into such a white ink composition is referred to as a white colorant.

[0032] The content (solid content) of the white colorant in the white ink composition is from 5% by mass to 20% by mass, preferably from 7% by mass to 20% by mass, more preferably from 9% by mass to 15% by mass, and even more preferably from 9% by mass to 13% by mass. If the content of the white colorant is within the above range, nozzle clogging of the recording device is unlikely to occur, and the ink layer has an increased shielding property, so that an image with better color development and image quality can be formed.

[0033] Dispersants The white colorant is preferably capable of being stably dispersed in water, and therefore may be dispersed using a dispersant. The dispersant may be any of a surfactant, a resin dispersant, etc., and is selected from those capable of improving the dispersion stability of the white colorant in the white ink composition containing the above-mentioned white colorant. In addition, the white colorant may be used as a self-dispersing white colorant by modifying the surface of the white colorant by oxidizing or sulfonating the surface of the white colorant with, for example, ozone, hypochlorous acid, fuming sulfuric acid, etc.

[0034] Examples of the resin dispersant include (meth)acrylic resins and salts thereof, 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, and vinylnaphthalene-(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 copolymer. Examples of the water-soluble resins include styrene resins and salts thereof, such as styrene-based (meth)acrylic acid ester copolymers, styrene-maleic acid copolymers, and styrene-maleic anhydride copolymers; urethane resins and salts thereof, which are polymeric compounds (resins) containing urethane bonds formed by the reaction of an isocyanate group and a hydroxyl group and may be linear and / or branched, and may have a crosslinked structure; polyvinyl alcohols; vinyl naphthalene-maleic acid copolymers and salts thereof; vinyl acetate-maleic acid ester copolymers and salts thereof; and vinyl acetate-crotonic acid copolymers and salts thereof. Among these, preferred are copolymers of a monomer having a hydrophobic functional group and a monomer having a hydrophilic functional group, and polymers made of a monomer having both a hydrophobic functional group and a hydrophilic functional group. The copolymers may be in the form of any of random copolymers, block copolymers, alternating copolymers, and graft copolymers.

[0035] Commercially available acrylic resins used as resin dispersants include BYK-187, BYK-190, BYK-191, BYK-194N, and BYK-199 (manufactured by BYK-Chemie Co., Ltd.), Aron A-210, A6114, AS-1100, AS-1800, A-30SL, A-7250, and CL-2 (manufactured by Toagosei Co., Ltd.).

[0036] In addition, commercially available styrene-based resins used as resin dispersants include, for example, X-200, X-1, X-205, X-220, and X-228 (manufactured by Seiko PMC Corporation), Nopcosperse (registered trademark) 6100 and 6110 (manufactured by San Nopco Ltd.), Joncryl 67, 586, 611, 678, 680, 682, and 819 (manufactured by BASF), DISPERBYK-190 (manufactured by BYK Japan KK), N-EA137, N-EA157, N-EA167, N-EA177, N-EA197D, N-EA207D, and E-EN10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0037] Furthermore, commercially available urethane resins used as resin dispersants include BYK-182, BYK-183, BYK-184, BYK-185 (manufactured by BYK-Chemie Co., Ltd.), TEGO Disperse710 (manufactured by Evonic Tego Chemi), Borchi (registered trademark) Gen1350 (manufactured by OMG Borschers), and the like.

[0038] The dispersant may be used alone or in combination of two or more. The total content of the dispersant is 0.2 parts by mass or more and 60 parts by mass or less, preferably 1.0 parts by mass or more and 50 parts by mass or less, more preferably 2 parts by mass or more and 40 parts by mass or less, and even more preferably 3.0 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the white colorant. By making the content of the dispersant 0.2 parts by mass or more relative to 100 parts by mass of the white colorant, the dispersion stability of the white colorant can be further improved. In addition, if the content of the dispersant is 60 parts by mass or less relative to 100 parts by mass of the white colorant, the viscosity of the obtained dispersion can be kept low.

[0039] Among the above-listed dispersants, it is more preferable to use a resin dispersant, particularly at least one selected from acrylic resins, styrene resins, and urethane resins. In this case, it is more preferable that the weight average molecular weight of the dispersant is 500 or more. By using such a resin dispersant as a dispersant, odor is reduced and the dispersion stability of the white colorant can be further improved.

[0040] 1.2.1.3.Resin particles The white ink composition used in the recording method according to this embodiment may contain resin particles. The resin particles can further improve the adhesion of an image formed by the white ink composition applied to a recording medium.

[0041] Examples of the resin particles include resin particles made of urethane resin, acrylic resin, fluorene resin, polyolefin resin, rosin-modified resin, terpene resin, polyester resin, polyamide resin, epoxy resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, ethylene vinyl acetate resin, etc. These resin particles are often handled in an emulsion form, but may also be in the form of a powder. The resin particles may be used alone or in combination of two or more kinds.

[0042] Urethane resin is a general term for resins having urethane bonds. In addition to urethane bonds, urethane resins may include polyether-type urethane resins containing ether bonds in the main chain, polyester-type urethane resins containing ester bonds in the main chain, and polycarbonate-type urethane resins containing carbonate bonds in the main chain. As urethane resins, commercially available products may be used, such as Superflex 460, 460s, 840, and E-4000 (commercially available). The agent may be selected from among commercially available products such as Rezamin D-1060, D-2020, D-4080, D-4200, D-6300, and D-6455 (trade names, manufactured by Dainichi Seiyaku Co., Ltd.), Takelac WS-6021 and W-512-A-6 (trade names, manufactured by Mitsui Chemicals Polyurethanes, Inc.), Sancure 2710 (trade name, manufactured by Lubrizol), and Parmarin UA-150 (trade name, manufactured by Sanyo Chemical Industries, Ltd.).

[0043] Acrylic resin is a general term for polymers obtained by polymerizing at least an acrylic monomer such as (meth)acrylic acid or a (meth)acrylic acid ester as one component, and examples thereof include resins obtained from acrylic monomers and copolymers of acrylic monomers and other monomers. Examples thereof include acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers. Further examples thereof include copolymers with vinyl monomers such as styrene.

[0044] As the acrylic monomer, acrylamide, acrylonitrile, etc. can also be used. For the resin emulsion using an acrylic resin as a raw material, a commercially available product may be used, and may be selected from, for example, FK-854 (trade name, manufactured by Chuo Rika Kogyo Co., Ltd.), Mowinyl 952B, 718A (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Nipol LX852, LX874 (trade names, manufactured by Nippon Zeon Co., Ltd.), etc.

[0045] As described above, in this specification, the acrylic resin may be a styrene-acrylic resin. In addition, in this specification, the term "(meth)acrylic" means at least one of acrylic and methacrylic.

[0046] Styrene-acrylic resins are copolymers obtained from styrene monomers and acrylic monomers, and examples thereof include styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylate copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylate copolymers. The styrene-acrylic resin may be a commercially available product, and may be selected from, for example, 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 (trade names, manufactured by BASF), Mowinyl 966A, 975N (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Vinyblan 2586 (manufactured by Nissin Chemical Industry Co., Ltd.), and the like.

[0047] The polyolefin resin has an olefin such as ethylene, propylene, butylene, etc. in the structural skeleton, and a known one can be appropriately selected and used. As the olefin resin, a commercially available product can be used, and for example, it may be selected from among Arrowbase CB-1200, CD-1200 (product name, manufactured by Unitika Ltd.), etc.

[0048] The resin particles may be supplied in the form of an emulsion. Examples of commercially available resin emulsions include Microgel E-1002 and E-5002 (product names of Nippon Paint Co., Ltd., styrene-acrylic resin emulsions), 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), 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), Polysol PTFE-2 ... (Product name of Showa Denko K.K.), Polysol SAE1014 (Product name, styrene-acrylic resin emulsion, manufactured by Zeon Corporation), Saivinol SK-200 (Product name, acrylic resin emulsion, manufactured by Saiden Chemical Industries Co., Ltd.), AE-120A (Product name of JSR Corporation, acrylic resin emulsion), AE373D (Product name of E-Tech Corporation, carboxy-modified styrene-acrylic resin emulsion), Seikadyne 1900W (Product name of Dainichiseika Chemical Industries Co., Ltd., ethylene-vinyl acetate resin emulsion), Vinyblan 2682 (acrylic resin emulsion), Vinyblan 2886 (vinyl acetate-acrylic resin emulsion), Vinyblan 5202 (acrylic acetate resin emulsion) (Product name of Nissin Chemical Industries Co., Ltd.), Elitel KA-5071S, KT -8803, KT-9204, KT-8701, KT-8904, KT-0507 (Unitika Ltd. product name, polyester resin emulsion), Hi-Tech 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 Polyurethanes Inc. product name, urethane resin emulsion), Superflex 870, 800, 150, 420, 460, 470, 610, 700 (Dai-ichi Kogyo Seiyaku Co., Ltd. product name, urethane resin emulsion), Parmarin UA-150 (Sanyo Chemical Industries, Ltd. product name, urethane resin emulsion), Sancure 2710 (Lubrizol Japan, urethane resin emulsion), NeoRez R-9660, R-9637, R-940 (Kusumoto Chemicals Co., Ltd., urethane resin emulsion), Adeka Bontiter HUX-380,290K (ADEKA Corporation, urethane resin emulsion), Mowinyl 966A, Mowinyl 7320 (Nippon Synthetic Chemical Industry Co., Ltd.), Joncryl 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 (all manufactured by BASF), NK Binder R-5HN (manufactured by Shin-Nakamura Chemical Co., Ltd.), Hydran WLS-210 (non-crosslinked polyurethane: manufactured by DIC Corporation), Joncryl 7610 (manufactured by BASF), etc. may be selected and used.

[0049] The glass transition temperature (Tg) of the resin particles is preferably -50°C or more and 200°C or less, more preferably 0°C or more and 150°C or less, and even more preferably 50°C or more and 100°C or less. When the glass transition temperature (Tg) of the resin particles is within the above range, the durability and clogging resistance tend to be more excellent. The glass transition temperature is measured, for example, using a differential scanning calorimeter "DSC7000" manufactured by Hitachi High-Tech Science Corporation in accordance with JIS K7121 (Method of measuring transition temperature of plastics).

[0050] The Tg of the resin particles can be adjusted by adjusting the type and composition ratio of the monomers during the resin polymerization, paying attention to the individual Tg of each monomer used, thereby making it possible to adjust the Tg of the entire resin of the resin particles.

[0051] The volume average particle size of the resin particles is preferably from 10 nm to 300 nm, more preferably from 30 nm to 300 nm, further preferably from 30 nm to 250 nm, and particularly preferably from 40 nm to 220 nm.

[0052] When resin particles are contained in the white ink composition, the content, in terms of solids, relative to the total mass of the white ink composition is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, and even more preferably 2% by mass or more and 10% by mass or less.

[0053] 1.2.1.4.Water The white ink composition used in the recording method according to this embodiment may contain water. If the white ink composition and the non-white ink composition described below are water-based inks, the environmental impact can be further reduced. In addition, if the white ink composition and the non-white ink composition are water-based inks, The white ink composition is easily mixed with the ink and the image quality (OD value) is easily reduced, but the recording method according to this embodiment allows the formation of an image with excellent image quality. Thus, the white ink composition is preferably an aqueous ink. An aqueous ink is a composition containing water as one of the main solvent components. Water may be contained as the main solvent component of the white ink composition, and is a component that evaporates and scatters when dried. The water is preferably pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, from which ionic impurities have been removed as much as possible. In addition, it is preferable to use water sterilized by ultraviolet irradiation or addition of hydrogen peroxide, etc., since it is possible to suppress the generation of mold and bacteria when the ink is stored for a long period of time. The content of water is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more and 99% by mass or less, and particularly preferably 55% by mass or more and 95% by mass or less, based on the total amount of the white ink composition.

[0054] Organic Solvents The white ink composition used in the recording method according to this embodiment may contain an organic solvent. One of the functions of the organic solvent is to improve the wettability of the white ink composition to the recording medium and to increase the moisture retention of the white ink composition. Examples of the organic solvent include esters, alkylene glycol ethers, cyclic esters, nitrogen-containing solvents, polyhydric alcohols, and the like. Examples of the nitrogen-containing solvent include cyclic amides and non-cyclic amides. Examples of the non-cyclic amides include alkoxyalkylamides.

[0055] Examples of esters include glycol monoacetates such as 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, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and methoxybutyl acetate; Examples of glycol diesters include ethylene 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.

[0056] The alkylene glycol ethers may be mono- or di-ethers of alkylene glycol, and alkyl ethers are preferred. Specific examples include alkylene glycol monoalkyl ethers such as 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 of the alkylene glycol dialkyl ether include alkylene glycol 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.

[0057] Furthermore, among the alkylene glycols, diethers tend to dissolve or swell the resin particles in the ink more easily than monoethers, and are therefore more preferred in terms of improving the abrasion resistance of the formed image.

[0058] Examples of the 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 of the methylene group adjacent to the carbonyl group is substituted with an alkyl group having 1 to 4 carbon atoms.

[0059] Examples of the alkoxyalkylamides include 3-methoxy-N,N-dimethylpropanamide, 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, Examples of the propionamide include N-dimethylpropionamide, 3-n-propoxy-N,N-diethylpropionamide, 3-n-propoxy-N,N-methylethylpropionamide, 3-iso-propoxy-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.

[0060] Examples of the cyclic amides include lactams, such as pyrrolidones such as 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone. These are preferred in terms of promoting the formation of a film on the resin particles, and 2-pyrrolidone is particularly preferred.

[0061] These nitrogen-containing solvents are preferred in that they promote the formation of a film on the resin particles. In particular, it is preferred to use 2-pyrrolidone and 3-methoxy-N,N-dimethylpropanamide, and it is more preferred to use 2-pyrrolidone.

[0062] In addition, the alkoxyalkylamides used are compounds represented by the following general formula (1): It is also preferable to

[0063] R 1-O-CH2CH2-(C=O)-NR 2 R 3 (1)

[0064] In the above formula (1), R 1 represents an alkyl group having 1 to 4 carbon atoms, and R 2 and R 3 each independently represents a methyl group or an ethyl group. The "alkyl group having 1 to 4 carbon atoms" can be a linear or branched alkyl group, for example, 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 kinds.

[0065] The function of the compound represented by formula (1) is, for example, to enhance the surface drying property and fixability of the white ink composition attached on the low-absorbency recording medium. In particular, the compound represented by formula (1) is excellent in the action of moderately softening and dissolving vinyl chloride resin. Therefore, the compound represented by formula (1) can soften and dissolve the recording surface containing the vinyl chloride resin, and penetrate the white ink composition into the inside of the low-absorbency recording medium. By penetrating the white ink composition into the low-absorbency recording medium in this way, the white ink composition is firmly fixed and the white ink composition is easily dried. Therefore, the obtained image is likely to have excellent surface drying property and fixability.

[0066] In addition, in the above formula (1), R 1 is more preferably a methyl group having one carbon atom. 1 The normal boiling point of the compound where R is a methyl group is 1 is lower than the standard boiling point of a compound having an alkyl group with 2 to 4 carbon atoms. 1 When a compound in which R is a methyl group is used, the surface dryness of the adhesion area (particularly the surface dryness of an image recorded in a hot and humid environment) can be further improved in some cases.

[0067] When the compound represented by formula (1) is used, the content of the compound is not particularly limited, but is about 5% by mass to 50% by mass, and preferably 8% by mass to 48% by mass, based on the total mass of the white ink composition. When the content of the compound represented by formula (1) is within the above range, the fixability and surface dryness of the image (particularly the surface dryness when recorded in a high-temperature and high-humidity environment) can be further improved in some cases.

[0068] In the white ink composition, the nitrogen-containing solvent is preferably 60% by mass or less (does not exceed 60% by mass) relative to the total content of the organic solvents (100% by mass). Furthermore, it is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. In particular, it is preferably not contained in excess of 18% by mass, more preferably not contained in excess of 12% by mass, even more preferably not contained in excess of 6% by mass, and particularly preferably not contained in excess of 3% by mass. The nitrogen-containing solvent may be 0% by mass or more relative to the total content of the organic solvents (100% by mass). When the content of the nitrogen-containing solvent in the white ink composition is within the above range, the color development is excellent and the image quality tends to be improved. This is presumably because the surface smoothness of the recorded matter on which the image is formed is improved and light scattering on the surface is reduced. In addition, it is preferable to contain a nitrogen-containing solvent from the viewpoint of the abrasion resistance of the recorded matter, but when the content exceeds the above range, the abrasion resistance tends to be poor. This is thought to be because the drying properties of the white ink composition decrease; in other words, if there are areas where the ink is insufficiently dried during the image formation process, the white colorant will aggregate in those areas, causing uneven dispersion of the colorant in the recorded material, and making it more likely that damage will occur due to these unevennesses in the ink layer on the recorded material.

[0069] The content of the nitrogen-containing solvent relative to the total mass of the white ink composition is preferably 30% by mass or less. The lower limit may be 0% by mass, and is 0% by mass or more. Further, it is preferably 2 to 25% by mass. %, more preferably 4 to 20 mass %, and even more preferably 8 to 15 mass %.

[0070] Furthermore, when the white ink composition and a non-white ink composition described below each contain a nitrogen-containing solvent, or when only one of them contains a nitrogen-containing solvent, it is preferable that the content of the nitrogen-containing solvent in the white ink composition is less than that in the non-white ink composition, which tends to result in more excellent color development and improved image quality.

[0071] This is presumably because the drying properties of the white ink composition are relatively superior to those of the non-white ink compositions, which makes it less likely for the white colorant to aggregate and cause uneven dispersion of the colorant in the recorded matter, and the colorant is distributed evenly on the surface of the ink layer on the recorded matter, improving surface smoothness and reducing light scattering on the surface.

[0072] The nitrogen-containing solvent content of the white ink composition is preferably at least 1% by mass less than that of the non-white ink composition, more preferably at least 3% by mass less, and even more preferably at least 5% by mass less, and preferably no more than 15% by mass less.

[0073] Examples of polyhydric alcohols include 1,2-alkanediols (e.g., alkanediols such as ethylene glycol, propylene glycol (also known as propane-1,2-diol), 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol), polyhydric alcohols (polyols) other than 1,2-alkanediols (e.g., diethylene glycol, dipropylene glycol, 1,3-propanediol, and 1,3-butanediol (also known as 1,3-butylene glycol), glycol), 1,4-butanediol, 1,5-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.

[0074] Polyhydric alcohols can be divided into alkanediols and polyols. Alkanediols are diols of alkanes having 5 or more carbon atoms. The number of carbon atoms of the alkanes is preferably 5 to 15, more preferably 6 to 10, and further preferably 6 to 8. 1,2-alkanediols are preferred.

[0075] The polyols are polyols of alkanes having 4 or less carbon atoms, or intermolecular condensation products of hydroxyl groups of polyols of alkanes having 4 or less carbon atoms. The number of carbon atoms of the alkane is preferably 2 to 3. The number of hydroxyl groups in the molecule of the polyols is 2 or more, preferably 5 or less, and more preferably 3 or less. When the polyols are the intermolecular condensation products, the number of intermolecular condensations is 2 or more, preferably 4 or less, and more preferably 3 or less. The polyhydric alcohols can be used alone or in combination of two or more.

[0076] Alkanediols and polyols can function primarily as penetrating solvents and / or moisturizing solvents, but alkanediols tend to have stronger penetrating solvent properties, while polyols tend to have stronger moisturizing solvent properties.

[0077] When the white ink composition contains an organic solvent, the organic solvent may be used alone or in combination of two or more kinds. The total content of the organic solvent relative to the total mass of the white ink composition is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 18% by mass or less, and particularly preferably 15% by mass or less. By having the organic solvent content within the above range, a better balance between wetting and spreading properties and drying properties can be achieved. The lower limit is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.

[0078] The normal boiling point of the organic solvent is preferably 150° C. or higher, more preferably 180° C. or higher, and even more preferably 200° C. or higher. In addition, the normal boiling point of the organic solvent is preferably 280° C. or lower, more preferably 270° C. or lower, and even more preferably 250° C. or lower. When the normal boiling point of the organic solvent is within the above range, the white ink composition is more excellent in terms of clogging recovery properties and abrasion resistance, and this is preferable.

[0079] The white ink composition preferably does not contain more than 2% by mass of a polyol organic solvent that is liquid in an environment of 25° C. and has a normal boiling point of more than 280° C., more preferably does not contain more than 1.5% by mass, and even more preferably does not contain more than 0.5% by mass, based on the total mass of the white ink composition. The lower limit of the content is 0% by mass or more, and may not be contained at all. This improves the drying property of the white ink composition attached to the recording medium, and improves the adhesion of the white ink composition to the recording medium. Examples of polyol organic solvents having a normal boiling point of more than 280° C. include glycerin, triethylene glycol, and polyethylene glycol monomethyl ether. Note that polyol organic solvents having a normal boiling point of more than 280° C. do not include alkanolamines such as triethanolamine and triisopropanolamine. Furthermore, it is also preferable from the above viewpoint that the content of organic solvents (not limited to polyol organic solvents) having a normal boiling point of more than 280° C. is within the above range.

[0080] The white ink composition has a polyhydric alcohol content of preferably 1% by mass or more and 27% by mass or less, more preferably 2% by mass or more and 15% by mass or less, and even more preferably 3% by mass or more and 13% by mass or less, in terms of better abrasion resistance and the like.

[0081] Surfactants The white ink composition used in the recording method according to this embodiment may contain a surfactant. The surfactant has a function of reducing the surface tension of the white ink composition and improving the wettability with the recording medium. Among the surfactants, for example, acetylene glycol-based surfactants, silicone-based surfactants, and fluorine-based surfactants can be preferably used.

[0082] The acetylene glycol surfactant is not particularly limited, but examples thereof include Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, and DF110D (all trade names, manufactured by Air Products & Chemicals, Inc.). , 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 trade names, manufactured by Nissin Chemical Industry Co., Ltd.), Acetylenol E00, E00P, E40, E100 (all trade names, manufactured by Kawaken Fine Chemicals Co., Ltd.).

[0083] The silicone surfactant is not particularly limited, but a polysiloxane compound is preferred. The polysiloxane compound is not particularly limited, but for example, a polyether-modified organosiloxane is preferred. Commercially available products of the polyether-modified organosiloxane include, for example, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (all trade names, manufactured by BYK Japan), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-601 2, KF-6015, and KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0084] As the fluorosurfactant, it is preferable to use a fluorine-modified polymer, and specific examples include BYK-3440 (manufactured by BYK Japan), Surflon S-241, S-242, S-243 (all trade names, manufactured by AGC Seimi Chemical Co., Ltd.), and Futergent 215M (manufactured by NEOS Corporation).

[0085] When the white ink composition contains a surfactant, multiple types of surfactants may be contained. When the white ink composition contains a surfactant, the content of the surfactant may be 0.1% by mass or more and 2% by mass or less, preferably 0.4% by mass or more and 1.5% by mass or less, and more preferably 0.5% by mass or more and 1.0% by mass or less, based on the total mass of the white ink composition.

[0086] Wax The white ink composition used in the recording method according to this embodiment may contain wax. Wax has a function of imparting lubricity to an image formed by the white ink composition, and therefore can reduce peeling of the image formed by the white ink composition.

[0087] Examples of components constituting the wax include plant and animal waxes such as carnauba wax, candelilla wax, beeswax, rice wax, and lanolin; petroleum waxes such as paraffin wax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, and petrolatum; mineral waxes such as montan wax and ozokerite; synthetic waxes such as carbon wax, Hoechst wax, polyolefin wax, and stearic acid amide; natural and synthetic wax emulsions and blended waxes such as α-olefin-maleic anhydride copolymers; and the like, which can be used alone or in combination. Among these, polyolefin waxes (particularly polyethylene wax and polypropylene wax) and paraffin wax are preferred from the viewpoint of their excellent effect of increasing the fixation to soft packaging films.

[0088] As the wax, commercially available products can be used as they are, and examples thereof include Nopcoat PEM-17 (trade name, manufactured by San Nopco Ltd.), Chemipearl W4005 (trade name, manufactured by Mitsui Chemicals Inc.), and AQUACER 515, 539, and 593 (all trade names, manufactured by BYK Japan KK).

[0089] In addition, in cases where the recording method includes a heating step or the like, in order to prevent the wax from melting too much and its performance from deteriorating, it is preferable to use a wax having a melting point of preferably 50.0°C or higher and 200.0°C or lower, more preferably 70.0°C or higher and 180.0°C or lower, and even more preferably 90.0°C or higher and 150.0°C or lower.

[0090] The wax may be supplied in the form of an emulsion or suspension. The content of the wax is 0.1% by mass or more and 10.0% by mass or less, more preferably 0.5% by mass or more and 5.0% by mass or less, and even more preferably 0.5% by mass or more and 2.0% by mass or less, calculated as solid content, based on the total mass of the white ink composition. When the content of the wax is within the above range, the function of the wax can be satisfactorily exhibited. Note that, when either or both of the white ink composition and the non-white ink composition described below contain wax, the function of imparting lubricity to the image can be sufficiently obtained.

[0091] Additives The white ink composition used in the recording method according to this embodiment may contain additives such as ureas, amines, and sugars. Ureas include urea, ethylene urea, tetramethyl urea, and the like. Examples of such anionic surfactants include aryl glycine, 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, and acetylcarnitine).

[0092] Examples of the amines include diethanolamine, triethanolamine, triisopropanolamine, etc. The ureas and amines may function as a pH adjuster.

[0093] Examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0094] Other The white ink composition used in the recording method according to this embodiment may further contain components such as preservatives, antifungal agents, rust inhibitors, chelating agents, viscosity adjusters, antioxidants, and antifungal agents, as necessary.

[0095] 1.2.1.10. Physical properties of white ink composition From the viewpoint of ensuring appropriate wetting and spreading properties on a recording medium, the white ink composition used in the recording method according to this embodiment has a surface tension of 40.0 mN / m or less, preferably 38.0 mN / m or less, more preferably 35.0 mN / m or less, and even more preferably 30.0 mN / m or less at 25.0° C. The surface tension can be measured by checking the surface tension when a platinum plate is wetted with the composition in an environment of 25.0° C. using an automatic surface tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

[0096] The viscosity of the white ink composition used in the recording method according to this embodiment is preferably from 1.5 mPa·s to 15.0 mPa·s, more preferably from 1.5 mPa·s to 7.0 mPa·s, and even more preferably from 1.5 mPa·s to 5.5 mPa·s at 20° C. When the white ink composition is applied to a recording medium by an inkjet method, it is easy to efficiently form a predetermined image on the recording medium.

[0097] 1.3. Non-white ink application process The recording method according to this embodiment includes a non-white ink applying step of applying a non-white ink composition containing a non-white coloring material onto a recording medium.

[0098] 1.3.1. Non-white ink composition The non-white ink composition used in the recording method according to this embodiment contains a non-white coloring material.

[0099] 1.3.1.1. Non-white colorants The non-white coloring material contained in the non-white ink composition refers to a coloring material other than the above-mentioned white coloring material. Examples of the non-white coloring material include dyes and pigments. The non-white coloring material is preferably a coloring material such as cyan, yellow, magenta, or black.

[0100] Specifically, the pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, quinocyanine pigments, and the like. Polycyclic pigments such as phthalon pigments, dye chelates, dye lakes, nitro pigments, nitroso pigments, aniline black, daylight fluorescent pigments, carbon black, etc. can be used. The above pigments can be used alone or in combination of two or more. Furthermore, glittering pigments can be used as non-white colorants.

[0101] Specific examples of pigments include, but are not limited to, the following:

[0102] Examples of black pigments include No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 2200B, etc. (all manufactured by Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. (all manufactured by Carbon Columbia), Rega1 400R, Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (manufactured by CABOT JAPAN Co., Ltd.). KK)), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color B1ack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex Examples of carbon blacks include Special Black 6, Special Black 5, Special Black 4A, and Special Black 4 (all manufactured by Degussa).

[0103] Examples of yellow pigments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, and 180.

[0104] Examples of magenta pigments include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48(Ca), 48(Mn), 57(Ca), 57:1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, and CI Pigment Violet. 19, 23, 32, 33, 36, 38, 43, and 50.

[0105] Cyan pigments include, for example, CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, and 66, and CI Vat Blue 4 and 60.

[0106] In addition, pigments other than magenta, cyan, and yellow are not particularly limited, but examples thereof include CI Pigment Green 7, 10, CI Pigment Brown 3, 5, 25, 26, and CI Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, and 63.

[0107] The pearl pigment is not particularly limited, but examples thereof include pigments having a pearlescent luster or an interference luster, such as titanium dioxide-coated mica, fish scale foil, and bismuth oxychloride.

[0108] The metallic pigment is not particularly limited, but examples thereof include particles of a simple substance such as aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, copper, or an alloy thereof.

[0109] As the dye, various dyes that are usually used in ink jet recording, such as direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes, can be used.

[0110] The non-white colorant is preferably one that can be stably dispersed or dissolved in water, and may be dispersed using a dispersant as necessary. Examples of the dispersant include the same dispersants that are used to improve the dispersibility of the white colorant in the white ink composition described above.

[0111] The content of the non-white coloring material is preferably 0.3% by mass or more and 20.0% by mass or less, more preferably 0.5% by mass or more and 15.0% by mass or less, and particularly preferably 0.5% by mass or more and 6.0% by mass or less, based on the total mass of the non-white ink composition. When the content of the non-white coloring material is within the above range, clogging of the nozzle of the recording device is unlikely to occur, and an image with better color development and better image quality may be formed. The non-white coloring material contained in the non-white ink composition may have high or low coagulation properties, but it is preferable that the coagulation property is high in terms of better bleeding resistance and the like.

[0112] When a pigment is used as the non-white coloring material, the volume average particle diameter of the pigment particles is preferably 10 nm to 300 nm, more preferably 30 nm to 250 nm, even more preferably 50 nm to 250 nm, and particularly preferably 70 nm to 200 nm. The volume average particle diameter of the non-white coloring material is measured in the initial state using the above-mentioned method for confirming the volume average particle diameter. When the volume average particle diameter is within the above range, it is preferable in that the desired coloring material is easily available and the characteristics of the coloring material can be easily made preferable.

[0113] Other ingredients The non-white ink composition used in the recording method according to this embodiment may contain, in addition to the non-white colorant, components such as resin particles, organic solvents, surfactants, water, wax, additives, resin dispersants, preservatives / antifungals, rust inhibitors, chelating agents, viscosity adjusters, antioxidants, and antifungal agents.

[0114] Since these components are all similar to those in the white ink composition described above, detailed description will be omitted by replacing the “white ink composition” with the “non-white ink composition.” The non-white ink composition can contain these components that may be contained in the white ink composition, or the preferred contents thereof, independently of the white ink composition.

[0115] Physical Properties The viscosity of the non-white ink composition used in the recording method according to this embodiment is preferably from 1.5 mPa·s to 15.0 mPa·s, more preferably from 1.5 mPa·s to 7.0 mPa·s, and even more preferably from 1.5 mPa·s to 5.5 mPa·s at 20° C. When the non-white ink composition is applied to a recording medium by an inkjet method, it is easy to efficiently form a predetermined image on the recording medium.

[0116] The non-white ink composition used in the recording method according to this embodiment has a surface tension of 40.0 mN / m or more at 25.0° C. in order to ensure appropriate wetting and spreading properties on a recording medium. The surface tension is preferably 38.0 mN / m or less, more preferably 35.0 mN / m or less, and even more preferably 30.0 mN / m or less. The surface tension is measured in the same manner as for the white ink composition described above.

[0117] 1.4. Aspects of the White Ink Application Process and the Non-White Ink Application Process In the recording method according to this embodiment, the white ink application step and non-white ink application step described above are performed by relative scanning of the recording head and recording medium, the white ink application step and the non-white ink application step are performed on the same scanned area of ​​the recording medium by the same relative scanning, and in the recording area to which the white ink composition and the non-white ink composition are applied, the amount of application of the white ink composition is 60% by mass or less relative to 100% by mass of the application of the non-white ink composition per unit area.

[0118] By using the recording device described below, the white ink application process and the non-white ink application process can be performed by relative scanning of the recording head and the recording medium, and the white ink application process and the non-white ink application process can be performed on the same scanning area of ​​the recording medium by the same relative scanning.

[0119] The term "scanning area" refers to the locus area of ​​the projection on the recording medium when the relative positional relationship between the recording head and the recording medium is changed by moving either one of the recording head or the recording medium while projecting the recording head in the recording medium direction. Alternatively, it includes the locus area of ​​the projection on the recording medium when the relative positional relationship between the recording head and the recording medium is changed by moving both the recording head and the recording medium while projecting the recording head in the recording medium direction. Alternatively, it refers to the part on the recording medium where the recording head moves relative to the recording medium when scanning is performed.

[0120] The scanning referred to here is scanning in the ink deposition process, scanning performed while ink is being ejected, and is also called main scanning.

[0121] Relative scanning refers to scanning performed by moving either the print head or the print medium, i.e., the print head may be moved relative to the print medium, or the print medium may be moved relative to the print head.

[0122] Carrying out the white ink depositing step and the non-white ink depositing step by the same relative scan means that the scan for carrying out the white ink depositing step and the scan for carrying out the non-white ink depositing step are carried out simultaneously.

[0123] Performing a white ink application process and a non-white ink application process on the same scanned area of ​​the recording medium by the same relative scan means that the white ink scanning area and the non-white ink scanning area performed by the same scan have at least a partial overlapping area.

[0124] Such a white ink application process and a non-white ink application process may be performed multiple times on the same scanning area of ​​the recording medium by the same relative scan, and recording may be performed by this method. When multiple scans are performed, it is preferable that a sub-scan is performed between the scans. The sub-scan is performed by moving the relative position of either the recording head or the recording medium in a direction intersecting the above-mentioned scanning direction. In this way, the relative position of the recording head and the recording medium differs between the scans in a direction intersecting the scanning direction. In the sub-scan, ink is not ejected from the recording head to the recording medium. Therefore, the sub-scan is not a scan. It is sufficient that the sub-scan is also a relative scan. In other words, the recording head may be moved relative to the recording medium, or the recording medium may be moved relative to the recording head.

[0125] Incidentally, when scanning is performed multiple times and sub-scanning is also performed, the scanning is also called main scanning.

[0126] In this way, in the recording area where the white ink composition and the non-white ink composition are applied, the amount of the white ink composition applied (adhesion amount ratio) is 60% by mass or less, preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 15% by mass or less, relative to the amount of the non-white ink composition applied per unit area being 100% by mass. On the other hand, the above-mentioned adhesion amount ratio is not limited to a lower limit, but is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. Also, 30% by mass or more is preferable. Within such a range, it is possible to form an image with excellent image quality, and it is possible to achieve compatibility with excellent printing speed. It is also preferable in that the components of the white ink (particularly the pigment) give the image hiding properties.

[0127] Here, the term "unit area" refers to an area having a predetermined area, and may be an area that allows confirmation of the ratio of the amount of attached white ink to the amount of attached non-white ink. If recording is performed using only white ink or only non-white ink, it is preferable that the concentration of the white ink and the concentration of the non-white ink are constant at each location within the unit area. The unit area is, for example, an area of ​​1×1 mm. Or an area of ​​2×2 mm, or an area of ​​3×3 mm. It is sufficient that the recording area at least has an area in which the amount of attached white ink composition relative to 100% by mass of attached non-white ink composition per unit area is within the above range, but it is preferable that the maximum value of the attachment amount ratio is within the above range in the recording area.

[0128] In addition, it is preferable that the amount of white ink composition adhered relative to the amount of non-white ink composition adhered per unit area satisfies the above relationship in the region where the amount of adherence of the non-white ink composition is the maximum amount in the recording region. More preferably, in the region where the amount of adherence of the non-white ink composition is less than the maximum amount in the recording region and is at least half of the maximum amount, the amount of adherence of the white ink composition relative to the amount of adherence of the non-white ink composition per unit area is within the above range. Even more preferably, in the region where the amount of adherence of the non-white ink composition is less than the maximum amount in the recording region and is at least 20% of the maximum amount, the amount of adherence of the white ink composition relative to the amount of adherence of the non-white ink composition per unit area is within the above range.

[0129] In the recording area where the white ink composition and the non-white ink composition were applied, the maximum amount of the white ink composition applied was 7 mg / inch 2 It is preferable that the density is less than 5 mg / inch. 2 More preferably, it is 1.5 mg / inch or less. 2 More preferably, it is 1 mg / inch or less. 2 It is particularly preferable that the maximum adhesion amount is 0.1 mg / inch or less. 2 It is preferable that the concentration is 0.3 mg / inch or more. 2More preferably, it is 0.5 mg / inch or more. 2 More preferably, it is 1 mg / inch or more. 2 When the maximum adhesion amount of the white ink composition is within the above range, the contact area with the non-white ink composition increases and they become more easily mixed, which tends to result in better image quality.

[0130] In the recording area where the white ink composition and the non-white ink composition were applied, the maximum amount of the non-white ink composition applied was 15 mg / inch 2 It is preferable that the density is less than 13 mg / inch. 2 More preferably, it is 11 mg / inch or less. 2 More preferably, it is 9 mg / inch or less. 2 It is particularly preferable that the maximum adhesion amount is 4 mg / inch or less. 2 It is preferable that the concentration is 5 mg / inch or more. 2 More preferably, it is 7 mg / inch or more. 2 It is more preferable that the composition of the non-white ink is more than or equal to the above. When the maximum amount of adhesion of the substance is within the above range, the contact area with the white ink composition increases and mixing becomes easier, which tends to result in better image quality.

[0131] When ink is applied to a unit area by multiple scans, the above-mentioned adhesion amount ratio and each adhesion amount are the total ink adhesion amount ratio and ink adhesion amount for the multiple scans.

[0132] The amount of non-white ink applied may vary depending on the location in the image, depending on the color or density of the image, but even in that case, it is preferable that the ratio of the amount of applied ink is within the above range at each location in the image. In that case, it is also possible and preferable to vary the amount of applied white ink depending on the amount of applied non-white ink at each location in the image. In this case, it is preferable that the ratio of the amount of applied ink is easily within the above range at each location in the image.

[0133] 1.5.Recording Device An example of a recording apparatus for implementing the recording method according to the present embodiment will be described with reference to the drawings.

[0134] Fig. 1 is a schematic cross-sectional view showing a recording device. Fig. 2 is a perspective view showing an example of the configuration of the carriage and its surroundings of the recording device 1 of Fig. 1. As shown in Figs. 1 and 2, the recording device 1 includes a recording head 2, an IR heater 3, a platen heater 4, a heating heater 5, a cooling fan 6, a pre-heater 7, a ventilation fan 8, a carriage 9, a platen 11, a carriage moving mechanism 13, a transport means 14, and a control unit CONT. The operation of the entire recording device 1 is controlled by the control unit CONT shown in Fig. 2.

[0135] 1.5.1. Recording Head A recording head 2 (hereinafter, simply referred to as "head 2") provided in a recording apparatus for carrying out a recording method according to this embodiment is scanned relatively to a recording medium M.

[0136] Here, "relative scanning of the recording head and the recording medium" includes a change in the relative positional relationship between the recording head or the recording medium due to either one of them moving in position, or a change in the relative positional relationship between the recording head and the recording medium due to both of them moving in position.

[0137] Any method may be used for ejecting droplets from the head 2. Examples of the recording method of the head 2 include a method in which a strong electric field is applied between a nozzle and an acceleration electrode placed in front of the nozzle, ink is continuously ejected from the nozzle in the form of droplets, and a printing information signal is applied to a polarizing electrode while the ink droplets fly between the deflection electrodes to record, or a method in which ink droplets are ejected in response to a printing information signal without being deflected (electrostatic attraction method), a method in which ink droplets are forcibly ejected by applying pressure to the ink liquid with a small pump and mechanically vibrating the nozzle with a quartz oscillator or the like, a method in which pressure and a printing information signal are simultaneously applied to the ink liquid with a piezoelectric element to eject and record ink droplets (piezo method), and a method in which ink liquid is heated and foamed with a microelectrode according to a printing information signal to eject and record ink droplets (thermal jet method).

[0138] Among these, the piezoelectric type can be further classified into those equipped with a thin-film type recording head and those equipped with a laminated type recording head. The thin-film type recording head includes a so-called unimorph type piezoelectric actuator, and the ink composition is ejected from the nozzle by the displacement of the piezoelectric actuator. On the other hand, the laminated type recording head is a type in which the wall of a pressure chamber communicating with the nozzle is pushed by driving the laminated type piezoelectric element in the d31 mode, thereby ejecting the ink composition from the nozzle.

[0139] A head capable of ejecting droplets using these methods is called an inkjet head. The recording head 2 is preferably an inkjet head, although there is no particular limitation thereto. That is, in the above-mentioned white ink application step and non-white ink application step, ink is preferably ejected from an inkjet head. In this case, when the recording device 1 in which the recording method according to the present embodiment is implemented is a type in which the position of the head 2 is moved (serial type), high-speed operation is possible, and a higher-resolution, high-quality image can be formed at high speed.

[0140] In a serial type recording device 1 as shown in Fig. 2, relative scanning between the recording head 2 and the recording medium M is performed by the operation of a carriage movement mechanism 13 that moves the carriage 9 in the medium width direction of the recording medium M. The medium width direction is the main scanning direction of the recording head 2. Scanning in the main scanning direction is also called main scanning.

[0141] Here, the main scanning direction is the direction in which the carriage 9 carrying the recording head 2 moves. In Fig. 1, it is the direction intersecting the sub-scanning direction indicated by the arrow SS, which is the transport direction of the recording medium M. In Fig. 2, the width direction of the recording medium M, that is, the direction indicated by S1-S2, is the main scanning direction MS, and the direction indicated by T1→T2 is the sub-scanning direction SS.

[0142] A single operation in which the recording head 2 forms an image while scanning in the main scanning direction MS, i.e., in either the direction of the arrow S1 or the arrow S2, is called a "main scan" or a "pass." When the movement direction of the recording head 2 in the main scanning direction MS is the same in pass 1 and pass 2, it is called "unidirectional printing," and when the movement direction of the recording head 2 in the main scanning direction MS is different in pass 1 and pass 2, it is called "bidirectional printing."

[0143] In unidirectional printing, for example, in pass 1, the recording head 2 ejects ink while moving in the direction of the arrow S2. After that, the recording head 2 is moved in the direction of the arrow S1 to return to the original position (return operation), the recording medium M is moved a predetermined distance in the T1→T2 direction, and the printing operation of pass 2 is performed in the same manner as pass 1. In unidirectional printing, since ink is ejected in the same direction in the main scanning direction MS, there is little deviation in the landing position of the ink dots in the main scanning direction MS, and it is suitable for printing images with good image quality. In addition, when the white ink nozzle row in the recording head is arranged on the leading side of the non-white ink nozzle row in the main scanning direction of the pass, it may be possible to form an image with better color development and better image quality when viewed from the image forming surface side of the recording medium. In addition, conversely, when the white ink nozzle row in the recording head is arranged on the trailing side of the non-white ink nozzle row in the main scanning direction of the pass, it may be possible to form an image with better color development and better image quality when viewed from the back of the image forming surface side of the recording medium.

[0144] In bidirectional printing, for example, in pass 1, the recording head 2 ejects ink while moving in the direction of the arrow S2. After that, the recording medium M is moved a predetermined distance in the T1→T2 direction, and in pass 2, ink is ejected while moving in the direction of the arrow S1 in the opposite direction to pass 1. In bidirectional printing, the return movement of the recording head 2 is not necessary, and two rows of dot lines can be formed while the recording head 2 moves back and forth in the main scanning direction MS. Therefore, the time required for printing can be reduced compared to unidirectional printing. In addition, when recording on a colorless and transparent recording medium, an image recorded by bidirectional printing is advantageous in that it is easy to see the same color when viewed from the side of the recording medium on which the image was formed and when viewed from the opposite side.

[0145] Furthermore, in the recording method according to the present embodiment, a scanning region where scanning is performed in one scan may be scanned a plurality of times, in which the above-mentioned white ink application step and non-white ink composition application step are performed in the same scanning region of the recording medium in the same scan. In other words, the recording method according to the present embodiment may be multi-pass recording. In multi-pass recording, the white ink composition and Since the non-white ink composition is more likely to mix with the white ink composition, the image quality tends to be poor. However, the recording method according to this embodiment makes it possible to form an image with excellent image quality even in multi-pass recording. Note that "multi-pass recording" refers to a recording operation in which the formation of each dot in the main scanning direction MS is completed in P passes (P is an integer of 2 or more).

[0146] Multi-pass printing will be specifically described with reference to Fig. 3. Fig. 3 is a schematic diagram showing the position of the nozzle row in each pass and the printing area at that position. In the following description, an example will be described in which dots are formed in all pixels of a printing medium M in four passes using one color of ink (e.g., a white ink composition).

[0147] In the first (n+1th pass (n is an integer equal to or greater than 0)) pass (1P) and the second (n+2th pass) pass (2P), the position of the nozzle row 16 is shifted in the sub-scanning direction by a distance equivalent to 1 / 4 of the head height Hh. In the third (n+3rd pass) pass (3P) and the fourth (n+4th pass) pass (4P), the position of the nozzle row 16 is also shifted in the sub-scanning direction by a distance equivalent to 1 / 4 of the head height Hh from the position of the previous pass. Here, "head height Hh" refers to a distance expressed as N×dp (N is the number of nozzles in the nozzle row 16, and dp is the nozzle pitch).

[0148] In the n+1th pass, dots are recorded on some of the pixels in the regions Q1 to Q4 of the recording medium M. In the n+2th pass, dots are recorded on some of the pixels in the regions Q2 to Q5 of the recording medium M. In the n+3th pass, dots are recorded on some of the pixels in the regions Q3 to Q6, and in the n+4th pass, dots are recorded on some of the pixels in the regions Q4 to Q7. In the region Q4, 100% of the pixels are recorded in a total of four passes, the n+1th, n+2nd, n+3rd, and n+4th passes. Note that, although it is assumed here that an image (solid image) in which dots are formed on all pixels of the recording medium M is formed on the recording medium M, the recorded image (printed image) represented by the actual dot data includes pixels in which dots are actually formed on the recording medium M and pixels in which dots are not actually formed on the recording medium M. In other words, whether or not a dot is actually formed on each pixel of the recording medium M is determined by the dot data generated by the halftone process.

[0149] The number of scans performed on the same scanning area is called the number of scans or the number of passes. For example, in FIG. 3, it is the number of scans performed on a scanning area that is the length in the SS direction (one-quarter the length of the nozzle row 16) over which the recording head moves relative to the recording medium in one sub-scan and extends in the MS direction. In the example of FIG. 3, the number of scans is 4. The number of scans is 1 or more, preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. Also, although not limited to this, it is preferably 24 or less, more preferably 16 or less, and even more preferably 10 or less.

[0150] The arrangement of nozzle rows on the nozzle surface of the recording head 2 included in the recording device in which the recording method according to the present embodiment is performed will be described with reference to FIG. 4. FIG. 4 shows a schematic example of the arrangement of nozzle rows on the nozzle surface 2a of the recording head 2. The recording head 2 has a nozzle surface 2a including a plurality of nozzle rows for ejecting a white ink composition and a non-white ink composition. In the example shown in FIG. 4, the nozzle surface 2a of the recording head 2 has a plurality of non-white ink nozzle rows 15a to 15d in which nozzles filled with the non-white ink composition are arranged in the sub-scanning direction, and a white ink nozzle row 16 in which nozzles filled with the white ink composition are arranged in the sub-scanning direction. In this specification, the portion of the recording head 2 having the white ink nozzle row 16 is also referred to as a white ink head, and the portion of the recording head 2 having the non-white ink nozzle rows 15a to 15d is also referred to as a non-white ink head. The white ink nozzle row 16 may be one row or multiple rows, and in the example shown in FIG. 4, the white ink nozzle row 16 is one row. In addition, in the example shown in FIG. 4, Although the white ink nozzle row 16 is disposed on the side of the arrow S1 in the main scanning direction MS, the positions of the white ink nozzle row 16 and the non-white ink nozzle rows 15a-15d are not particularly limited. In the following, the portion of the non-white ink nozzle rows 15a-15d that is used for recording and ejects ink during recording is referred to as the non-white ink ejection nozzle row. Similarly, the portion of the white ink nozzle row 16 that is used for recording and ejects the white ink composition during recording is referred to as the white ink ejection nozzle row.

[0151] In this embodiment, in the example of the nozzle array arrangement shown in Figure 4, when the non-white ink nozzle arrays 15a-15d and the white ink nozzle array 16 are projected along the main scanning axis MS, the white ink nozzle array 16 has a portion where it overlaps with the non-white ink nozzle arrays 15a-15d in the sub-scanning direction. Here, the overlapping portion is the range indicated by X in Figure 4, and refers to the length in the sub-scanning direction indicated by X that coincides with the region 3A where the white ink nozzle array 16 exists and the regions 3B-3E where the non-white ink nozzle arrays 15a-15d exist.

[0152] In the example shown in FIG. 4, the overlapping portion X is 100% of the length of the white ink nozzle row 16 in the sub-scanning direction, and is 100% of the length of the non-white ink nozzle rows 15a to 15d in the sub-scanning direction. Furthermore, all of the non-white ink nozzle rows 15a to 15d are non-white ink ejection nozzle rows, and all of the white ink nozzle rows 16 are white ink ejection nozzle rows. In this way, when the overlapping portion X is a 100% arrangement and the nozzle rows in use are 100% of each nozzle row, the above-mentioned white ink applying step and non-white ink applying step can be performed on the same scanning area of ​​the recording medium by the same relative scan. Furthermore, because the nozzle rows in use are arranged horizontally, the length of the recording head 2 in the sub-scanning direction can be shortened, which in turn makes it possible to miniaturize the entire device.

[0153] The length of portion X does not have to be 100% of the length of the white ink nozzle row 16 in the sub-scanning direction or the length of the non-white ink nozzle row 15a in the sub-scanning direction, as long as portion X is present in the nozzle row.

[0154] 1.5.2.Other Configurations 2, the cartridge 12 that supplies a white ink composition or a non-white ink composition to the recording head 2 includes a plurality of independent cartridges. The cartridge 12 is detachably mounted on a carriage 9 on which the recording head 2 is mounted. Each of the plurality of cartridges is filled with a different type of ink composition, and the white ink composition or the non-white ink composition is supplied from the cartridge 12 to each nozzle. Note that in this embodiment, an example in which the cartridge 12 is mounted on the carriage 9 is shown, but this is not limiting, and the cartridge 12 may be provided at a location other than the carriage 9 and may supply the ink composition to each nozzle by a supply pipe (not shown).

[0155] 1, the recording apparatus 1 includes an IR heater 3 and a platen heater 4 for heating a recording medium M when a white ink composition or a non-white ink composition is ejected from a recording head 2. In this embodiment, when drying the recording medium M in the drying step, the IR heater 3, a ventilation fan 8 described below, and the like can be used.

[0156] When the IR heater 3 is used, the recording medium M can be radiatively heated by radiating infrared rays from the recording head 2 side. This makes it easy for the recording head 2 to be heated at the same time, but compared to heating from the back side of the recording medium M by the platen heater 4 or the like, the temperature can be increased without being affected by the thickness of the recording medium M. In addition, various fans (for example, ventilation fan 8) may be provided to blow hot air or air at the same temperature as the environment onto the recording medium M to dry the ink composition on the recording medium M.

[0157] The platen heater 4 can heat the recording medium M via the platen 11 at a position facing the recording head 2 so that the white ink composition and non-white ink composition ejected by the recording head 2 can be dried quickly from the time they are applied to the recording medium M. The platen heater 4 is capable of conducting heat for the recording medium M and is used as necessary in the recording method of this embodiment. When used, it is preferable to control the surface temperature of the recording medium M to be 40.0° C. or lower.

[0158] The upper limit of the surface temperature of the recording medium M by the IR heater 3 and the platen heater 4 is preferably 60°C or less, more preferably 50°C or less. Furthermore, it is preferably 45.0°C or less, more preferably 40.0°C or less, even more preferably 38.0°C or less, and particularly preferably 35.0°C or less. The lower limit of the surface temperature of the recording medium M is preferably 25.0°C or more, more preferably 28.0°C or more, even more preferably 30.0°C or more, and particularly preferably 32.0°C or more. Also, 40°C or more is preferable. This can suppress drying and composition fluctuation of the white ink composition and non-white ink composition in the recording head 2, and suppress the adhesion of the resin in the ink composition to the inner wall of the recording head 2. In addition, the white ink composition and non-white ink composition can be fixed on the recording medium M early, and image quality can be improved.

[0159] The heater 5 is a heater for drying and solidifying the white ink composition or non-white ink composition attached to the recording medium M, that is, a heater for secondary heating or secondary drying. The heater 5 can be used in the post-heating process. By the heater 5 heating the recording medium M on which an image has been recorded, the moisture contained in the ink composition evaporates and dissipates more quickly, and an ink film is formed by the resin contained in the ink composition. In this way, the ink film is firmly fixed or adhered on the recording medium M, and the film-forming property is excellent, and an excellent high-quality image can be obtained in a short time. The upper limit of the surface temperature of the recording medium M by the heater 5 is preferably 120.0°C or less, more preferably 100.0°C or less, and even more preferably 90.0°C or less. In addition, the lower limit of the surface temperature of the recording medium M is preferably 60.0°C or more, more preferably 70.0°C or more, and even more preferably 80.0°C or more. By the temperature being within the above range, a high-quality image can be obtained in a short time.

[0160] The recording apparatus 1 may have a cooling fan 6. After the ink composition recorded on the recording medium M is dried, the ink composition on the recording medium M is cooled by the cooling fan 6, whereby an ink coating film with good adhesion can be formed on the recording medium M.

[0161] The recording apparatus 1 may also include a preheater 7 that preheats the recording medium M before the white ink composition or non-white ink composition is applied to the recording medium M. Furthermore, the recording apparatus 1 may also include a ventilation fan 8 so that the white ink composition or non-white ink composition applied to the recording medium M can be dried more efficiently.

[0162] Below the carriage 9, there are provided a platen 11 that supports the recording medium M, a carriage movement mechanism 13 that moves the carriage 9 relatively to the recording medium M, and a transport means 14 that is a roller that transports the recording medium M in the sub-scanning direction. The operations of the carriage movement mechanism 13 and the transport means 14 are controlled by a control unit CONT.

[0163] FIG. 5 is a functional block diagram of the recording device 1. The control unit CONT is a control unit for controlling the recording device 1. The interface unit 101 (I / F) is for transmitting and receiving data between a computer 130 (COMP) and the recording device 1. The CPU 102 is an arithmetic processing unit for controlling the entire recording device 1. The memory 103 The (MEM) is for securing an area for storing programs of the CPU 102, a working area, etc. The CPU 102 controls each unit through a unit control circuit 104 (UCTRL). The situation inside the recording device 1 is monitored by a detector group 121 (DS), and the control unit CONT controls each unit based on the detection results.

[0164] The transport unit 111 (CONVU) controls the sub-scanning (transport) of recording, specifically, controls the transport direction and transport speed of the recording medium M. Specifically, the transport direction and transport speed of the recording medium M are controlled by controlling the rotation direction and rotation speed of a transport roller driven by a motor.

[0165] The carriage unit 112 (CARU) controls the main scanning (pass) of printing, and specifically, moves the print head 2 back and forth in the main scanning direction. The carriage unit 112 includes a carriage 9 on which the print head 2 is mounted, and a carriage movement mechanism 13 for moving the carriage 9 back and forth.

[0166] The head unit 113 (HU) controls the amount of white ink composition or non-white ink composition discharged from the nozzles of the recording head 2. For example, if the nozzles of the recording head 2 are driven by piezoelectric elements, the operation of the piezoelectric elements in each nozzle is controlled. The head unit 113 controls the timing of deposition of each ink composition, dot size, etc. Also, the amount of deposition of the white ink composition or non-white ink composition per scan is controlled by a combination of controls of the carriage unit 112 and the head unit 113.

[0167] The drying unit 114 (DU) controls the temperatures of various heaters such as the IR heater 3, the pre-heater 7, the platen heater 4, and the heating heater 5.

[0168] The recording device 1 alternately repeats an operation of moving the carriage 9 carrying the recording head 2 in the main scanning direction and a transport operation (sub-scanning). At this time, when performing each pass, the control unit CONT controls the carriage unit 112 to move the recording head 2 in the main scanning direction, and controls the head unit 113 to eject droplets of a white ink composition or a non-white ink composition from predetermined nozzle holes of the recording head 2, and deposit the droplets of the white ink composition or the non-white ink composition on the recording medium M. In addition, the control unit CONT 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.

[0169] In the recording device 1, the recording area on which a plurality of droplets are deposited is gradually transported by repeating main scanning (passes) and sub-scanning (transport operation). Then, the droplets deposited on the recording medium M are dried by an after-heater 5, completing the image. Thereafter, the completed recorded matter may be wound into a roll by a winding mechanism, or transported by a flatbed mechanism.

[0170] 1.5.3. Variations A modified example of the recording apparatus for implementing the recording method according to this embodiment will be described below.

[0171] 1.5.3.1.Modifications of nozzle face arrangement In the recording method according to the present embodiment, it is sufficient that the above-mentioned white ink application process and non-white ink application process are performed on the same scanning area of ​​the recording medium by the same relative scanning. Therefore, the recording head 2 may be controlled so that each nozzle row is controlled to record using a nozzle row that is composed of a part of the nozzles. In other words, each nozzle row may be selected to have an ejection nozzle row and a non-ejection nozzle row.

[0172] Such a selection can be made, for example, by the user inputting the selection result to the control unit CONT. Also, a menu regarding the arrangement of the ejection nozzle array and the non-ejection nozzle array of each nozzle array may be stored in advance in the memory 103 or the like, and the user may select from this. Hereinafter, a set of nozzles in each nozzle array used for recording will be referred to as an ejection nozzle array. Also, a set of nozzles in each nozzle array not used for recording will be referred to as a non-ejection nozzle array. An ejection nozzle array is a set of nozzles used for recording and set to eject when recording, and if it is such a nozzle, a nozzle that has become defective in ejection due to an unintended malfunction of the nozzle during recording is also included in the ejection nozzle array. Also, a non-ejection nozzle array is a set of nozzles not used for recording and set not to eject when recording, and if it is such a nozzle, a nozzle that ejects for purposes other than image formation, such as maintenance purposes, is also included in the non-ejection nozzle array.

[0173] When two or more nozzle rows that are different from each other are arranged so that they completely overlap when projected in the main scanning direction MS, the liquid ejected from each nozzle row can be simultaneously deposited onto the same scanning area in one pass. In other words, with this arrangement, the white ink application process and the non-white ink application process can be performed on the same scanning area of ​​the recording medium by the same relative scan.

[0174] For example, FIG. 6 shows an example of the nozzle array arrangement shown in FIG. 4, in which one third of the white ink nozzle array 16 and the non-white ink nozzle arrays 15a-15d are set as non-ejection nozzle arrays on the upstream side in the sub-scanning direction and one third of the non-white ink nozzle arrays on the downstream side in the sub-scanning direction. Of the white ink nozzle array 16 and the non-white ink nozzle arrays 15a-15d, the hatched parts on the upstream and downstream sides in the sub-scanning direction are not used for recording, and the midstream parts without hatching are set as ejection nozzle arrays used for recording. The part where the white ink ejection nozzle array and the non-white ink ejection nozzle array completely overlap in the sub-scanning direction is X. In this method, although the overlapping part of the white ink nozzle array 16 and the non-white ink nozzle arrays 15a-15d is 100%, the overlapping part of the white ink ejection nozzle array and the non-white ink ejection nozzle array that is actually used is one third of the white ink ejection nozzle array, and one third of the non-white ink ejection nozzle array. The example in FIG. 6 is otherwise the same as FIG. 4. Even in this embodiment, the white ink depositing step and the non-white ink depositing step can be performed on the same scanning area of ​​the recording medium by the same relative scanning.

[0175] 7 shows another example of the arrangement of nozzle rows. In the example shown in FIG. 7, the nozzle surface 20a of the recording head 20 has a plurality of non-white ink nozzle rows 25a-25d in which a plurality of nozzles filled with a non-white ink composition are arranged in the sub-scanning direction, and a white ink nozzle row 26 in which a plurality of nozzles filled with a white ink composition are arranged in the sub-scanning direction. The white ink nozzle row 26 has a portion that overlaps with the non-white ink nozzle rows 25a-25d in the sub-scanning direction. Here, the overlapping portion is the range indicated by Y in FIG. 7, and refers to the length in the sub-scanning direction indicated by Y that coincides with the region 4A in which the white ink nozzle row 26 exists and the regions 4B-4E in which the non-white ink nozzle rows 25a-25d exist.

[0176] 7, overlapping portion Y is two-thirds the length in the sub-scanning direction of the white ink nozzle row 26, and two-thirds the length in the sub-scanning direction of the non-white ink nozzle rows 25a-25d. Even in such an arrangement of nozzle rows, overlapping portion Y is at least an ejection nozzle row, and the same relative scan can be performed on the same scanned area of ​​the recording medium.

[0177] It is to be noted that only the overlapping portion Y may be the ejection nozzle array, or the nozzle array portion other than the overlapping portion Y (i.e., the portion upstream or downstream in the SS direction from the overlapping portion Y) may also be the ejection nozzle array. In other words, as long as there is at least a scanning region in which the white ink application process and the non-white ink application process are performed on the same scanning region of the recording medium by the same relative scanning, That's good.

[0178] In this way, the white ink deposition step and the non-white ink deposition step can be performed on the same scanned area of ​​the recording medium with the same relative scan.

[0179] 8 is an example of a flowchart showing the process performed when recording is performed in the recording device 1. When starting recording, the control unit of the recording device determines the recording mode in step 400. The recording mode is a recording mode in which details of recording such as the arrangement of the ejection nozzle arrays and non-ejection nozzle arrays used in recording, the ejection amount, the manner of overlapping, the operation of the recording head during recording, and the operation of the recording medium are determined.

[0180] The recording mode is determined by an input signal input to the recording device 1 from an external device such as a computer, or by information input by a user to a user input unit included in the recording device 1. Here, the input signal from the external device or the information input by the user may be information directly specifying the recording mode, or may be information related to recording, such as information on the type of recording medium to be recorded, a recording speed specification, or an image quality specification. The information related to recording is not limited to these. In the latter case, the recording device 1 records in advance in the recording device 1, such as a control unit, corresponding information that defines a recording mode corresponding to the information related to recording, and determines the recording mode by referring to the corresponding information. Alternatively, the recording mode may be determined using AI technology (artificial intelligence technology).

[0181] In step S401, the determined print mode is identified. In steps S402 or S403, the ejection nozzle array is set according to the determined print mode. In step S404, printing is performed. Although two print modes, a first print mode and a second print mode, are shown in the figure, there may be three or more print modes.

[0182] In this example, the recording apparatus 1 is preferable because it can change the arrangement of the ejection nozzle arrays depending on the recording mode, enabling a variety of recording operations.

[0183] 1.5.3.2. Modified Recording Head The recording apparatus in Fig. 2 is a serial type recording apparatus equipped with a serial type recording head and performing a serial type recording method. On the other hand, the recording head 2 may be a line type recording head. Even in the case of a line type recording head, it is possible to relatively scan the recording medium M. And, according to the recording method of this embodiment, even if the amount of the attached white ink composition is relatively small, an image with excellent quality can be formed.

[0184] In Fig. 1, when the recording head 2 is a line-type recording head, the line-type recording head is provided so that the nozzle area formed in the direction intersecting the direction of the arrow SS, which is the transport direction of the recording medium M, can cover the entire intersecting direction of the recording medium M. Then, without moving the line-type recording head in the direction intersecting the direction of the arrow SS, which is the transport direction of the recording medium M, a recording operation (scanning) is performed while transporting the recording medium M in the SS direction. In this way, when the recording head 2 is a line-type recording head, the recording device 1 ejects a white ink composition and a non-white ink composition from the line-type recording head and deposits them on the recording medium M while moving the relative positions of the line-type recording head and the recording medium M, thereby performing recording. The number of scans is 1.

[0185] The line-type recording head has a nozzle surface including a plurality of nozzle rows that eject a white ink composition and a non-white ink composition, but the arrangement of the nozzle rows is not particularly limited as long as the white ink application step and the non-white ink application step can be performed on the same scanning area of ​​the recording medium by the same relative scanning.

[0186] 1.5.3.3.Modifications of Carriage Movement Mechanism 2, the recording device 1 records on the recording medium M by repeatedly performing a main scan of the recording head 2 and a sub-scan, which is the transport of the recording medium M, multiple times. Alternatively, a lateral scan method may be used in which an image is printed in a certain printing area on the recording medium M by only moving the recording head 2, without transporting the recording medium M. Even with this lateral scan method, the white ink application process and the non-white ink application process can be performed on the same scanning area of ​​the recording medium by the same relative scan.

[0187] Fig. 9 is a schematic side view showing a part of a recording device that performs recording by the lateral scan method. Fig. 10 is a schematic overhead view showing a part of a recording device that performs recording by the lateral scan method. A part 300 of the recording device includes a carriage movement mechanism 310 including a main scanning axis carriage movement mechanism 312 and a sub-scanning axis carriage movement mechanism 311, a carriage 320 including the recording head 2, and a transport roller 330 that transports the recording medium M.

[0188] The carriage movement mechanism 310 freely moves a carriage 320 including a recording head 2 (not shown) in a sub-scanning direction SS corresponding to the transport direction of the recording medium M, and a main scanning direction MS corresponding to the direction perpendicular to the transport direction of the recording medium M. The carriage movement mechanism 310 is made up of a sub-scanning axis carriage movement mechanism 311 that moves the carriage 320 in the sub-scanning direction MS, a main scanning axis carriage movement mechanism 312 that moves the sub-scanning axis carriage movement mechanism 311 in the main scanning direction MS, and a motor (not shown) that moves these.

[0189] The carriage 320 is provided on a sub-scanning axis carriage moving mechanism 311, and when the sub-scanning axis carriage moving mechanism 311 moves in the sub-scanning direction SS, the carriage 320 also moves in the sub-scanning direction SS. When the main scanning axis carriage moving mechanism 312 moves in the main scanning direction MS, the carriage 320 also moves in the main scanning direction MS. Then, by moving the carriage 320 in the sub-scanning direction SS while simultaneously moving it in the main scanning direction MS, the carriage 320 can be moved in a direction oblique to the sub-scanning direction SS. By intermittently ejecting the ink composition from the nozzles while the carriage 320 is moving, the white ink composition and the non-white ink composition can be deposited on the recording medium M along the oblique direction. Thereafter, the carriage 320 is moved in the main scanning direction MS by the main scanning axis carriage moving mechanism 312 via the sub-scanning axis carriage moving mechanism 311, and printing is performed while the carriage 320 moves in the oblique direction again.

[0190] In this way, an image can be printed on the recording medium M in the printing area by repeating the operation of depositing the white ink composition and the non-white ink composition on the recording medium M by moving the carriage 320 and the movement of the carriage 320 in the main scanning direction MS. A large number of images are printed on the continuous recording medium M by alternately repeating the operation of printing an image on the recording medium M supplied to the printing area (image forming operation) and the operation of transporting the recording medium M in the transport direction by the transport roller 330 and supplying a new portion of the recording medium M to the printing area (transport operation).

[0191] The carriage 320 can be moved in any manner, and the carriage 320 and the recording medium M may be scanned relatively by only the operation of the main scanning axis carriage movement mechanism 312, which moves the carriage 320 in the main scanning direction MS of the recording medium M, without operating the sub-scanning axis carriage movement mechanism 311. Then, after the movement of the carriage 320 in the main scanning direction MS of the recording medium M is completed, the sub-scanning axis carriage movement mechanism 311 moves the carriage 320 in the sub-scanning direction SS. In other words, the sub-scanning axis carriage movement mechanism 311 and the main scanning axis carriage movement mechanism 312 may be operated independently to perform recording on the recording medium M. Furthermore, either unidirectional printing or bidirectional printing may be used, and multi-pass recording may be performed.

[0192] 1.6.Other processes The recording method according to this embodiment may include a drying step of drying the liquid attached to the recording medium, a step of heating the recording medium (post-heating step), and the like.

[0193] 1.6.1.Drying process The recording method according to the present embodiment may have a drying step. The recording method according to the present embodiment may include a step of drying the recording medium before or during the application step of the white ink composition and the non-white ink composition. The drying step can be performed by a means of stopping the recording and leaving it as it is, or by a means of drying using a drying mechanism. Examples of the means of drying using a drying mechanism include a means of blowing air at room temperature or hot air to the recording medium (air blowing type), a means of irradiating the recording medium with radiation (infrared rays, etc.) that generates heat (radiation type), a member that contacts the recording medium and transfers heat to the recording medium (conduction type), and a combination of two or more of these means. When the method has a drying step, it is more preferable to perform the drying step using the conduction type or the air blowing type among these.

[0194] The surface temperature of the recording medium when the white ink composition and the non-white ink composition are applied is preferably 60° C. or lower, more preferably 50° C. or lower. Furthermore, it is preferably 45° C. or lower, and more preferably 40° C. or lower. On the other hand, it is preferably 20° C. or higher, and more preferably 20 to 60° C. Furthermore, it is preferably 27° C. or higher, more preferably 28° C. or higher, even more preferably 30° C. or higher, particularly preferably 32° C. or higher, particularly more preferably 40° C. or higher, and especially preferably 45° C. or higher. The temperature is the surface temperature of the part of the recording surface of the recording medium that receives the ink composition in the application step, and is the maximum temperature in the application step in the recording area. When the surface temperature is in the above range, it is more preferable in terms of image quality, abrasion resistance, reduced clogging, and high gloss.

[0195] The drying step can be performed simultaneously with the white ink application step and the non-white ink application step. During ink application, the surface temperature of the recording medium is preferably 43° C. or less, and more preferably 40° C. or less.

[0196] When a drying step for drying the recording medium is performed before the white ink applying step and the non-white ink applying step or during the white ink applying step and the non-white ink applying step, the surface temperature of the recording medium at the time when the white ink composition and the non-white ink composition are applied to the recording medium is preferably 30.0° C. or higher, preferably 35.0° C. or higher, and more preferably 40.0° C. or higher. In this way, when the white ink composition and the non-white ink composition contain resin particles, for example, a film is more likely to be formed, and therefore it may be possible to further improve the adhesion and abrasion resistance of the obtained image.

[0197] 1.6.2. Post-heating process The recording method according to the present embodiment may further include a post-heating step of heating the recording medium after each of the above-mentioned adhesion steps. The post-heating step may be performed, for example, by using an appropriate heating means. The post-heating step may be performed, for example, by an after-heater (corresponding to the heater 5 in the above-mentioned recording device example). The heating means is not limited to the heating means provided in the recording device, and other drying means may be used. This allows the obtained image to be dried and more sufficiently fixed, so that, for example, the recorded matter can be made ready for use sooner.

[0198] In this case, the temperature of the recording medium is not particularly limited, but may be set, for example, in consideration of the Tg of the resin component constituting the resin particles contained in the recording material. When taking into consideration the Tg of the resin component constituting the resin particles and wax, it is advisable to set the temperature at 5.0° C. or more, preferably 10.0° C. or more, higher than the Tg of the resin component constituting the resin particles.

[0199] The surface temperature of the recording medium reached by heating in the post-heating step is 30.0° C. or higher and 120.0° C. or lower, preferably 40.0° C. or higher and 100.0° C. or lower, more preferably 50.0° C. or higher and 95° C. or lower, and even more preferably 70° C. or higher and 90° C. or lower. The surface temperature of the recording medium reached by heating in the post-heating step is particularly preferably 80° C. or higher. If the temperature of the recording medium is within this range, the resin particles and wax contained in the recorded matter can be formed into a film and flattened, and the resulting image can be dried and fixed more sufficiently.

[0200] 2. Recording device A recording apparatus according to an embodiment of the present invention is a recording apparatus for recording on a recording medium, and includes a white ink head for depositing a white ink composition containing a white coloring material onto the recording medium, a non-white ink head for depositing a non-white ink composition containing a non-white coloring material onto the recording medium, and a scanning mechanism for relatively scanning the ink head and the recording medium, and performs recording by the above-mentioned recording method. With such a recording apparatus, it is possible to achieve both image formation with excellent image quality and excellent printing speed. In addition, when the recording head is a serial type, it is sufficient to arrange the nozzle rows to be used so that at least a portion of them overlap when projected in the main scanning direction, so that the length of the recording head in the sub-scanning direction can be shortened, and thus the entire device can be made smaller.

[0201] As the recording apparatus according to this embodiment, the recording apparatus as shown in the above-mentioned FIGS. 1 to 10 can be used.

[0202] In addition, in Fig. 4, the "white ink head" refers to the portion of the recording head 2 having the white ink nozzle row 16. In addition, in Fig. 4, the "non-white ink head" refers to the portion of the recording head 2 having the non-white ink nozzle rows 15a-15d. In addition, the "ink head" refers to a recording head combining a white ink head and a non-white ink head, and is illustrated as recording head 2 in Fig. 2. In addition, the "scanning mechanism" refers to the combination of the carriage movement mechanism 13 and the transport means 14 in Fig. 2.

[0203] 3. Working Example The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following, "%" is based on mass unless otherwise specified.

[0204] 3.1. Preparation of White and Non-White Ink Compositions Each component was mixed in the amounts shown in Tables 1 and 2 below, stirred at room temperature for 2 hours, and then filtered through a membrane filter having a pore size of 10 μm to obtain each white ink composition and each non-white ink composition.

[0205] The contents of the white ink composition and non-white ink composition shown in Tables 1 and 2 are in mass %, and the contents of the coloring material, resin, and wax are expressed as solid content equivalents. Ion-exchanged water was added so that the total mass of the composition was 100 mass %.

[0206] The coloring materials used in the preparation of the ink compositions were prepared by previously preparing coloring material dispersions as described below.

[0207] <Preparation of white colorant dispersion> First, 4 parts by mass of acrylic acid-acrylic acid ester copolymer (weight average molecular weight: 25,000, acid value: 18) was added as a resin dispersant to 155 parts by mass of ion-exchanged water in which 0.1 parts by mass of 30% ammonia water solution (neutralizer) was dissolved, and then dissolved. Titanium dioxide (CI Pigment White 6) was added at 40 parts by mass, and dispersed in a ball mill with zirconia beads for 10 hours. Then, impurities such as coarse particles and dust were removed by centrifugal filtration using a centrifuge, and the concentration of the white colorant was adjusted to 20% by mass, to obtain a white colorant dispersion. The particle diameter of the white colorant was 350 nm in average.

[0208] <Preparation of non-white colorant dispersion> First, 7.5 parts by mass of acrylic acid-acrylic acid ester copolymer (weight average molecular weight: 25,000, acid value: 180) was added as a resin dispersant to 160.5 parts by mass of ion-exchanged water in which 2 parts by mass of 30% aqueous ammonia solution (neutralizer) was dissolved, and dissolved. 30 parts by mass of CI Pigment Red 122 was added as a magenta colorant, and dispersion treatment was performed for 10 hours using a ball mill with zirconia beads. Then, centrifugal filtration was performed using a centrifuge to remove impurities such as coarse particles and dust, and the magenta colorant concentration was adjusted to 15% by mass, to obtain a non-white colorant (magenta colorant) dispersion. The average particle diameter of the magenta colorant at that time was 100 nm.

[0209] [Table 1]

[0210] [Table 2]

[0211] The following provides additional explanations for each component shown in Tables 1 and 2 above. <Coloring material> Titanium dioxide (white colorant): CI Pigment White 6 Magenta (non-white colorant): CI Pigment Red 122 <Resin> Styrene-acrylic: Trade name "Joncryl 62J", manufactured by BASF Japan Ltd. <Wax> Polyethylene: Product name "AQUACER539", manufactured by BYK <Surfactant> BYK348: Trade name of BYK Japan, silicone surfactant

[0212] 3.2.Evaluation Methodology 3.2.1. Recording test Each of the white ink compositions and non-white ink compositions obtained above was filled in an ink cartridge, and the ink cartridge was mounted on a recording device. The recording device used was a modified version of "SC-S40650" manufactured by Seiko Epson Corporation. The recording device was configured to record by multiple main scans in which the recording head moves in the main scanning direction and multiple sub-scans in which the recording medium moves in the sub-scanning direction. The recording head was configured as shown in FIG. 4, and had a white ink nozzle row (white ink nozzle row 16) in which nozzles were aligned in the sub-scanning direction and ejected a white ink composition, and a non-white ink nozzle row (non-white ink nozzle rows 15a to 15d) in which nozzles were aligned in the sub-scanning direction and ejected a non-white ink composition. In this case, the white ink nozzle row was arranged so that the portion where the white ink nozzle row overlapped with the non-white ink nozzle row in the sub-scanning direction was 100%.

[0213] In each recording apparatus, the ventilation fan and IR heater shown in FIG. 1 were provided above the recording head, and a platen heater was provided below the recording head.

[0214] The following two printing methods were used. <Printing method 1: Simultaneous printing> The recording head was configured as shown in Figure 4, and the entire white ink nozzle row was used for recording as a nozzle row for ejecting a white ink composition, and the entire non-white ink nozzle row was used for recording as a nozzle row for ejecting a non-white ink composition. This is a printing method in which the white ink composition and non-white ink composition are ejected simultaneously during scanning of the recording head (both the white ink composition and the non-white ink composition are deposited in one pass), and all nozzles in the white ink nozzle row and the non-white ink nozzle row serve as ejection nozzle rows. In Tables 3 and 4 below, "simultaneous" is listed as the printing method for simultaneous printing.

[0215] <Printing method 2: Pre-printing> Only the white ink nozzle row was used for recording as the white ink composition ejection nozzle row, and after the white ink was attached, the recording medium was returned and only the non-white ink nozzle row was used for recording as the non-white ink composition ejection nozzle row. A pattern made of non-white ink was attached to the pattern made of white ink that had been attached previously, superimposed thereon. That is, this is a printing method in which, after a scan in which the white ink composition of the recording head is attached, a scan in which the non-white ink composition is attached is performed in the area where the white ink composition has been attached, and there are no overlapping portions when each ejection nozzle row is projected in the main scanning direction. In Tables 3 and 4 below, the pre-deposition printing method is described as "pre-deposition".

[0216] The following two scanning methods were used. <Scanning method 1: Bidirectional printing> The print head moves in the main scanning direction to form an image in one operation (also called a "pass"). .) is a printing method in which the direction of movement of the recording head in the main scanning direction differs between pass 1 and pass 2. In Tables 3 and 4 below, "bidirectional" is listed as bidirectional printing.

[0217] <Scanning method 2: Unidirectional printing> A printing method in which the main scanning direction movement of the recording head is the same in pass 1 and pass 2. In Tables 3 and 4 below, "unidirectional" is listed as unidirectional printing. Note that the white ink nozzle row in the recording head is positioned ahead of the non-white ink nozzle row in the main scanning direction of the pass.

[0218] The spacing between adjacent nozzles in the nozzle row in the row direction was 360 dpi, and the number of nozzles was 360. The ink droplet mass and the number of ink droplets discharged were adjusted for the white ink composition and non-white ink composition so that the adhesion amounts in the recorded pattern were as shown in Tables 3 and 4 below. A 5 x 5 cm recorded pattern was recorded.

[0219] In addition, in simultaneous printing (printing method 1), four-pass printing was performed. In other words, the distance of one sub-scan was set to about one-fourth the length of the ejection nozzle row in the sub-scanning direction, so that deposition was performed in four passes on a certain area of ​​the recording medium.

[0220] In the pre-printing (printing method 2), four passes were made for the white ink composition and four passes were made for the non-white ink composition.

[0221] A transparent PET media (manufactured by Lintec Corporation, product name "E1000ZC") was used as the recording medium. The platen heater was controlled so that the recording medium was heated while the platen heater was in operation. The surface temperature of the recording medium in each example was measured and is shown in Tables 3 and 4 below as the "primary heating temperature".

[0222] If a drying method was performed after the adhesion process, it is noted in the table for each example as "Yes", and if a drying method was not performed after the adhesion process, it is noted as "No". Note that a combination of air blowing and conduction methods was used as the drying method, and this is noted in the table as "platen air blowing". The air blowing method had a wind speed of 2 m / s above the recording medium. For the conduction method, a platen heater was used. For the air blowing method, a ventilation fan was used, and room temperature air (25°C) was blown onto the recording medium. The drying step (secondary drying step) after the adhesion step was carried out so that the surface temperature of the recording medium was 70°C.

[0223] [Table 3]

[0224] [Table 4]

[0225] 3.2.2. Evaluation of ink sedimentation recovery Each of the white ink compositions obtained above was filled into an ink cartridge, which was then loaded into a recording device and allowed to stand for 24 hours.2 An image was recorded in the same manner as in Example 1, except that the above conditions were met. The whiteness (L value) of the image was measured using a spectrophotometer "i1pro2" (product name, manufactured by X-RITE Corporation) and judged according to the following evaluation criteria. The measurement conditions were a light source of D50 and an observation angle of 2°. In addition, a black mount of ISO concealment chart (manufactured by Cortec Corporation, product name "KL-2A") was used as the background during the measurement. (Evaluation Criteria) A: L value ≧ 75 B: 75>L value ≧ 70 C:70>L value

[0226] 3.2.3. Evaluation of image quality (specific OD value) The reflection density (OD value) of the recording pattern portion on the front side of each recorded matter obtained in the above recording test was measured using a spectrophotometer "i1pro2" (product name, manufactured by X-RITE). The measurement conditions were a light source of D50 and an observation angle of 2°. In each example and each comparative example, the same conditions were used except that the printing method was simultaneous printing or pre-printing, and recorded recording patterns were prepared and measured in the same manner. The OD values ​​of the measured examples, comparative examples, and reference examples were evaluated based on the ratio (ratio OD value) to the OD value of the reference example recorded by the pre-printing printing method, and judged according to the following evaluation criteria. Note that the reference example was pre-printed, so it was set to 100%. The same applies to the following evaluation tests. (Evaluation Criteria) A: The specific OD value is 100% or more. B: The specific OD value is 90% or more and less than 100%. C: The specific OD value is 80% or more but less than 90%. D: The specific OD value is less than 80%.

[0227] 3.2.4. Evaluation of specific abrasion resistance The recorded pattern portion of each recorded matter obtained in the above recording test was rubbed back and forth 50 times with a friction element attached to a Gakushin type friction fastness tester "AB-301" (product name manufactured by Tester Sangyo Co., Ltd.) with a white cotton cloth (compliant with JIS L 0803) under a load of 200 g. Then, the ratio (peeled area ratio) of the peeled area in each Example, Comparative Example, and Reference Example to the peeled area of ​​the recorded pattern recorded by the pre-printing method in the same manner as in the image quality evaluation was visually observed and judged according to the following evaluation criteria. (Evaluation Criteria) A: The peeled area ratio is 100% or more. B: The peeled area ratio is 90% or more and less than 100%. C: The peeled area ratio is 80% or more and less than 90%. D: The peeled area ratio is 70% or more and less than 80%. E: The peeled area ratio is less than 70%.

[0228] 3.2.5. Evaluation of Print Speed ​​Ratio The time required to print each recorded matter obtained in the recording test was measured. The recording medium used was A4 size. The ratio (printing time ratio) of the printing time in each example, comparative example, and reference example to the printing time when recording was performed by the first-in-first-printing method, as in the image quality evaluation, was evaluated according to the following evaluation criteria. (Evaluation Criteria) A: The printing time ratio is less than 80%. B: The printing time ratio is 80% or more and less than 100%. C: The printing time ratio is 100% or more.

[0229] 3.3.Evaluation Results The results of the evaluation tests are shown in Tables 3 and 4 above.

[0230] From the above evaluation results, it was found that in each of the Examples, both excellent printing speed and excellent image quality were achieved. In contrast, in each of the Comparative Examples, the image quality was poor. In each of the Reference Examples, the printing speed was poor. The details are described below.

[0231] It was found from Examples 1 to 4 that the specific abrasion resistance was improved as the adhesion ratio of the white ink composition was reduced. This is presumably because the organic solvent contained in the white ink composition was less likely to remain on the recording medium.

[0232] It was found from Examples 2, 6 and 10 that the image quality was slightly degraded whether the deposition ratio of the non-white ink composition was high or low.

[0233] From Examples 1 and 8, when a nitrogen-containing solvent was contained, the specific abrasion resistance was more excellent.

[0234] From Examples 2 and 9, when the nitrogen-containing solvent was 2-pyrrolidone, the image quality was superior.

[0235] From Examples 1 and 15, when the white ink composition did not contain glycerin, the specific abrasion resistance was superior.

[0236] From Examples 17 to 20, when the content of 2-pyrrolidone in the white ink composition was low, there was a tendency for the specific abrasion resistance to be more excellent.

[0237] From Examples 21 and 22, it was found that when the content of 2-pyrrolidone in the non-white ink composition was high, the specific abrasion resistance tended to be better.

[0238] From Examples 1 and 26, when the primary heating temperature was high, the image quality was slightly deteriorated.

[0239] From Examples 1 and 27, when the total amount of the organic solvent was large, the image quality was slightly deteriorated.

[0240] From Examples 7 and 28, when the scanning method was unidirectional scanning and the white ink nozzle row was positioned ahead of the non-white ink nozzle row in the main scanning direction of the pass, the image quality was slightly better.

[0241] The following can be derived from the above-described embodiment.

[0242] One aspect of the recording method is A recording method for recording on a recording medium, comprising the steps of: a white ink applying step of applying a white ink composition containing a white color material to the recording medium; a non-white ink applying step of applying a non-white ink composition containing a non-white colorant to the recording medium, the white ink depositing step and the non-white ink depositing step are performed by scanning a recording head and the recording medium relative to each other; the white ink depositing step and the non-white ink depositing step are performed on the same scanning area of ​​the recording medium by the same relative scanning, In the recording area to which the white ink composition and the non-white ink composition are applied, the amount of the white ink composition is 100% by mass relative to the amount of the non-white ink composition applied per unit area. The amount of the composition attached is 60 mass % or less.

[0243] In the above recording method, The recording head may be an inkjet head, and the white ink applying step and the non-white ink applying step may be performed by ejecting ink from the inkjet head.

[0244] In the above recording method, A scanning process may be performed a plurality of times in which the white ink depositing step and the non-white ink depositing step are performed in the same scanning area of ​​the recording medium in the same scanning area in a single scanning step.

[0245] In the above recording method, In the recording area to which the white ink composition and the non-white ink composition are applied, the maximum amount of the white ink composition applied is 7 mg / inch 2 It may be the following.

[0246] In the above recording method, The white ink composition may have a white coloring material content of 5 to 20% by mass, and the non-white ink composition may have a non-white coloring material content of 0.5 to 6% by mass.

[0247] In the above recording method, The white ink composition and the non-white ink composition may each be a water-based ink.

[0248] In the above recording method, The white ink composition and the non-white ink composition may each have an organic solvent content of 30% by mass or less.

[0249] In the above recording method, The white ink composition and the non-white ink composition may each contain an organic solvent having a normal boiling point of 150 to 280°C.

[0250] In the above recording method, The white ink composition and the non-white ink composition may each contain no more than 2 mass % of a polyol organic solvent having a normal boiling point of more than 280° C.

[0251] In the above recording method, The white ink composition and the non-white ink composition may each contain a nitrogen-containing solvent in an amount not exceeding 18% by mass relative to 100% by mass of the total content of the organic solvents.

[0252] In the above recording method, The white ink composition may contain less nitrogen-containing solvent than the non-white ink composition.

[0253] In the above recording method, The recording medium may be a low absorption recording medium or a non-absorption recording medium.

[0254] In the above recording method, The recording medium may be a non-white recording medium.

[0255] One aspect of the recording device is A recording device for recording on a recording medium, a white ink head that deposits a white ink composition containing a white coloring material onto the recording medium; a non-white ink head that deposits a non-white ink composition containing a non-white colorant onto the recording medium; a scanning mechanism for scanning the ink head and the recording medium relative to each other; Recording is performed by the recording method of the above aspect.

[0256] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiment, for example, a configuration that has the same function, method, and result, or a configuration that has the same purpose and effect. The present invention also includes a configuration in which non-essential parts of the configuration described in the embodiment are replaced. The present invention also includes a configuration that has the same action and effect as the configuration described in the embodiment, or a configuration that can achieve the same purpose. The present invention also includes a configuration in which publicly known technology is added to the configuration described in the embodiment. [Explanation of symbols]

[0257] 1... recording device, 2, 20... recording head, 2a, 20a... nozzle surface, 3... IR heater, 4... platen heater, 5... heater, 6... cooling fan, 7... pre-heater, 8... ventilation fan, 9... carriage, 11... platen, 12... cartridge, 13... carriage moving mechanism, 14... conveying means, 15a to 15d, 25a to 25d... non-white ink nozzle row, 16, 26... white ink nozzle row, 3A, 4A... area where white ink nozzle row exists, 3B to 3E, 4B to 4E... area where non-white ink nozzle row exists, 101... interface a control unit for controlling the conveyance of the recording medium, 102...CPU, 103...memory, 104...unit control circuit, 111...conveyance unit, 112...carriage unit, 113...head unit, 114...drying unit, 121...group of detectors, 130...computer, 300...part of the lateral scan recording device, 310...carriage movement mechanism, 311...sub-scanning axis carriage movement mechanism, 312...main scanning axis carriage movement mechanism, 320...carriage, 330...conveyance roller, CONT...control unit, MS...main scanning direction, SS...sub-scanning direction, M...recording medium, X,Y...overlapping portion

Claims

1. A recording method for recording on a recording medium, comprising the steps of: a white ink applying step of applying a white ink composition containing a white color material to the recording medium; a non-white ink applying step of applying a non-white ink composition containing a non-white colorant to the recording medium, the white ink depositing step and the non-white ink depositing step are performed by scanning a recording head and the recording medium relative to each other; the white ink depositing step and the non-white ink depositing step are performed on the same scanning area of ​​the recording medium by the same relative scanning, a scanning step of performing the white ink application step and the non-white ink application step in the same scanning area of ​​the recording medium in the same scanning area in a single scanning step is performed a plurality of times; a recording method in which, in a recording area to which the white ink composition and the non-white ink composition are applied, the amount of the white ink composition applied is 60% by mass or less relative to 100% by mass of the non-white ink composition applied per unit area.

2. 2. The recording method according to claim 1, wherein the recording head is an inkjet head, and the white ink applying step and the non-white ink applying step are performed by ejecting ink from the inkjet head.

3. 3. The recording method according to claim 1, wherein a scanning step of performing the white ink application step and the non-white ink application step in the same scanning area of ​​the recording medium in a single scanning step is performed 2 to 24 times in a scanning area where scanning is performed in one scanning step.

4. In the recording area to which the white ink composition and the non-white ink composition are applied, the maximum amount of the white ink composition applied is 7 mg / inch. ２ 4. The recording method according to claim 1, wherein:

5. 5. The recording method according to claim 1, wherein the white ink composition has a content of the white coloring material of 5 to 20% by mass, and the non-white ink composition has a content of the non-white coloring material of 0.5 to 6% by mass.

6. The recording method according to claim 1 , wherein the white ink composition and the non-white ink composition are each a water-based ink.

7. 7. The recording method according to claim 1, wherein the white ink composition and the non-white ink composition each have an organic solvent content of 30% by mass or less.

8. 8. The recording method according to claim 1, wherein the white ink composition and the non-white ink composition each contain an organic solvent having a normal boiling point of 150 to 280° C.

9. The recording method according to claim 1 , wherein the white ink composition and the non-white ink composition each contain no more than 2 mass % of a polyol organic solvent having a normal boiling point of more than 280° C.

10. 10. The recording method according to claim 1, wherein each of the white ink composition and the non-white ink composition does not contain a nitrogen-containing solvent in an amount of more than 18% by mass relative to a total content of the organic solvents of 100% by mass.

11. 11. The recording method according to claim 1, wherein the white ink composition has a lower content of the nitrogen-containing solvent than the non-white ink composition.

12. 12. The recording method according to claim 1, wherein the recording medium is a low-absorption recording medium or a non-absorption recording medium.

13. The recording method according to claim 1 , wherein the recording medium is a non-white recording medium.

14. A recording method as described in any one of claims 1 to 13, wherein the recording head is mounted on a carriage.

15. A recording method described in any one of claims 1 to 14, wherein the amount of adhesion of the non-white ink composition per unit area in the recording area ranges from the maximum adhesion amount to 20 mass% of the maximum adhesion amount, and the amount of adhesion of the white ink composition is 60 mass% or less for an adhesion amount of the non-white ink composition per unit area of ​​100 mass%.

16. A recording device for recording on a recording medium, a white ink head that deposits a white ink composition containing a white coloring material onto the recording medium; a non-white ink head that deposits a non-white ink composition containing a non-white colorant onto the recording medium; a scanning mechanism for scanning the ink head and the recording medium relative to each other; A recording apparatus that performs recording by the recording method according to any one of claims 1 to 15.

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