Recording method and recording apparatus

Abstract

To provide a recording method which hardly causes staining in the non-image area of a recorded matter even if an image is formed on a non-absorbent recording medium or a low-absorbent recording medium including a substrate with a large in-plane surface roughness (Sa).SOLUTION: There is provided a recording method which comprises: an ink adhesion step of ejecting an aqueous coloring ink composition containing a coloring material from an ink jet head to adhere to a recording medium; and a clear ink adhesion step of ejecting an aqueous clear ink composition from the ink jet head to adhere to the recording medium, wherein the recording medium is a non-absorbent recording medium or a low-absorbent recording medium having a recording medium surface with an in-plane surface roughness (Sa) of 0.2 μm or more, the clear ink composition comprises a resin and a wax and does not comprise an organic solvent, which is a polyol having a standard boiling point of 280°C or more, in an amount of 0.5 mass% or more based on the total mass of the clear ink composition and the clear ink composition is adhered to a non-image area, which is an area other than an image area to which the coloring ink composition of the recording medium is adhered.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Inkjet recording is capable of recording high-resolution images using relatively simple equipment, and has been rapidly developing in various fields. In order to improve the abrasion resistance of recorded materials, the use of clear ink containing resins in combination with inkjet recording has been investigated.

[0003] For example, Patent Document 1 discloses an inkjet recording method that uses a clear ink composition that contains an alkanediol having 7 to 10 carbon atoms, a water-soluble alcohol as a dissolution aid that dissolves the alkanediol having 7 to 10 carbon atoms, water, and silicone-based composite resin particles, and that does not contain a colorant, and attempts are made to improve the abrasion resistance, etc., of the resulting image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-144764 Summary of the Invention [Problem to be solved by the invention]

[0005] When an image is formed on a non-absorbent recording medium or a low-absorbent recording medium with a large in-plane surface roughness (Sa) to produce a recorded product, the non-image area (area where no image is recorded) may become dirty when the recorded product is rubbed. Therefore, a recording method is required that is less likely to cause dirt in the non-image area of ​​the recorded product when an image is formed on such a recording medium. [Means for solving the problem]

[0006] One aspect of the recording method according to the present invention is to an ink deposition step of ejecting an aqueous colored ink composition containing a colorant from an inkjet head and depositing the ink onto a recording medium; a clear ink deposition step of ejecting an aqueous clear ink composition from an inkjet head and depositing the ink onto a recording medium; and The recording medium is a non-absorbent or low-absorbent recording medium having an in-plane surface roughness (Sa) of the recording medium surface of 0.2 μm or more, the clear ink composition contains a resin and a wax, and does not contain an organic solvent that is a polyol having a normal boiling point of 280°C or higher in an amount of 0.5% by mass or more relative to the total mass of the clear ink composition; The clear ink composition is applied to non-image areas, which are areas other than image areas, which are areas of the recording medium where the colored ink composition is applied.

[0007] One aspect of the recording device according to the present invention is A recording device that performs the above recording method, The ink jet recording device includes the colored ink composition, the clear ink composition, and an inkjet head that ejects the colored ink composition and the clear ink composition. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an inkjet recording apparatus. [Figure 2] FIG. 1 is a perspective view showing an example of the configuration of the periphery of a carriage of an inkjet recording apparatus. [Figure 3] FIG. 2 is a schematic diagram showing an example of an arrangement of inkjet heads. [Figure 4] FIG. 2 is a schematic diagram showing an example of an arrangement of inkjet heads. [Figure 5] Table 1 shows the compositions used in the examples and comparative examples. [Figure 6] Table 2 shows the compositions used in the examples and comparative examples. [Figure 7] Table 3 shows the evaluation conditions and evaluation results of the examples. [Figure 8]Table 4 shows the evaluation conditions and evaluation results of the examples. [Figure 9] Table 5 shows the evaluation conditions and evaluation results of Examples, Comparative Examples, and Reference Examples. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes embodiments of the present invention. The embodiments described below are examples of the present invention. The present invention is not limited to the following embodiments, and includes various modified forms that are implemented within the scope of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0010] 1. Recording method The recording method according to this embodiment includes an ink deposition step of ejecting an aqueous colored ink composition containing a colorant from an inkjet head and depositing it onto a recording medium, and a clear ink deposition step of ejecting an aqueous clear ink composition from the inkjet head and depositing it onto the recording medium.

[0011] Non-absorbent or low-absorbent recording media, such as synthetic paper containing plastic as a base material, have paper-like texture, water resistance, and tear resistance. However, when an image is formed on such synthetic paper to produce a recorded product, the non-image area (area where no image is recorded) may become dirty when the recorded product is rubbed. One possible cause of this dirt is that the ink in the image area peels off and transfers to the non-image area.

[0012] This phenomenon is particularly likely to occur when printing multiple prints continuously or when handling recorded materials, when the non-image areas of the recording medium come into contact with the image areas and rub against the image areas. The synthetic paper has a surface irregularity, and it is thought that when the non-image areas rub against the image areas, the ink in the image areas peels off and transfers to the non-image areas, staining the non-image areas of the recorded material. Therefore, a recording method is needed that is less likely to stain the non-image areas of the recorded material, even when an image is formed on a non-absorbent or low-absorbent recording medium whose base has a high in-plane surface roughness (Sa).

[0013] 1.1. Recording medium The recording method of this embodiment uses a non-absorbent or low-absorbent recording medium whose substrate has an in-plane surface roughness (Sa) of 0.2 μm or more. Examples of such a recording medium include the low-absorbent or non-absorbent recording media described below, which have an in-plane surface roughness (Sa) of 0.2 μm or more.

[0014] A low-absorbency or non-absorbency recording medium refers to a recording medium that does not absorb liquid at all or absorbs very little. Quantitatively, a low-absorbency or non-absorbency recording medium is one that absorbs liquid 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 either: "Absorptive or non-absorbent." 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 Methods 2000 Edition." In contrast, absorbent recording media refers to recording media that do not fall under the category of low-absorbency or non-absorbent recording media.

[0015] The low-absorbency recording medium may be, for example, a recording medium having a low-absorbency coating layer on its surface, which is called coated paper. For example, the substrate may be paper, such as printing paper, art paper, coated paper, or matte paper, and the substrate may be a plastic film, such as polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, or polypropylene, coated with a polymer or the like on its surface, or coated with particles of silica, titanium, or the like together with a binder.

[0016] 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 absorption layer (receiving layer). Examples of such plastics include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

[0017] Among these, it is more preferable to use a recording medium having a polyolefin-based film substrate. "Polyolefin-based" is a general term for polymers whose monomer is alkene (olefin). Examples include polyethylene and polypropylene.

[0018] "In-plane surface roughness (Sa)" represents the average absolute value of the difference in height (z(x,y)) from the average plane of each measurement point in reference area A, and is expressed by the following formula. Details of "in-plane surface roughness (Sa)" are specified in ISO25178. "In-plane surface roughness (Sa)" is also called "arithmetic mean height Sa." Sa=(1 / A)∬ A |z(x,y)|dxdy

[0019] The surface roughness Sa can be measured, for example, using a laser microscope (VK-X1000 / manufactured by Keyence) by a method in accordance with ISO25178.

[0020] The surface roughness Sa of the recording medium surface to which the ink is applied is 0.2 μm or more, but in order to make the effects of the recording method of this embodiment more pronounced, it is preferably 0.3 μm or more, more preferably 0.4 μm or more, even more preferably 0.5 μm or more, and particularly preferably 0.6 μm or more. There is no particular upper limit to the surface roughness Sa, but it is preferably 1.5 μm or less, preferably 1.0 μm or less, and more preferably 0.8 μm or less.

[0021] The recording medium may contain inorganic particles on the surface of the substrate. Examples of inorganic particles that can be used include silica such as colloidal silica, inorganic oxides such as titanium dioxide, aluminum oxide (alumina), zinc oxide, antimony oxide, magnesium oxide, and zirconium oxide, inorganic carbonates such as calcium carbonate, and inorganic sulfates such as calcium sulfate, and mixtures thereof may also be used.

[0022] The shape of the inorganic particles may be, for example, spherical, rod-like, beaded or needle-like in which spherical particles are linked together, etc. Among these, spherical or rod-like shapes are preferred, and spherical shapes are particularly preferred.

[0023] The shape of the inorganic particles can be confirmed by observation with a scanning electron microscope. In the present invention, the term "spherical" means that the shape does not necessarily mean a beaded, rod-like, needle-like, or other shape formed by linked primary particles when observed with a scanning electron microscope, and is not limited to a perfect sphere or an oval sphere.

[0024] 1.2.Ink application process In the ink deposition step, a water-based colored ink composition containing a coloring material is ejected from an inkjet head and deposited on a recording medium.

[0025] 1.2.1. Colored ink composition The colored ink composition is a water-based ink composition containing a coloring material.

[0026] 1.2.1.(1) Colorants Examples of coloring materials include pigments and dyes.

[0027] (pigment) As the pigment, for example, inorganic pigments including carbon black and titanium white, organic pigments, etc. can be used.

[0028] Examples of inorganic pigments that can be used include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, iron oxide, titanium oxide, zinc oxide, and silica.

[0029] Examples of carbon black include No. 2300, 900, MCF88, No. 20B, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, and No. 2200B manufactured by Mitsubishi Chemical Corporation. Examples of carbon black include Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, and S170, Pretex 35, U, V, and 140U, and Special Black 6, 5, 4A, 4, and 250 manufactured by Degussa. Examples of carbon black include Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, and 700 manufactured by Columbia Carbon Corporation. Examples include Cabot Corporation's Regal 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, and Elftex 12.

[0030] Examples of organic pigments include quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments.

[0031] The colorant in the colored ink composition is preferably a quinacridone pigment. While quinacridone pigments have excellent color development and weather resistance, they tend to be easily redispersed by moisture. For this reason, when a colored ink composition containing a quinacridone pigment is used, the wet rub resistance may be poor. In contrast, the ink set according to this embodiment tends to provide good wet rub resistance even when a colored ink composition containing a quinacridone pigment is used.

[0032] Examples of quinacridone pigments include CI Pigment Red 122, 209, and 202, CI Pigment Violet 19, and CI Pigment Orange 48 and 49.

[0033] Specific examples of organic pigments that can be used in the colored ink composition include the following.

[0034] Examples of cyan pigments include CI Pigment Blue 1, 2, 3, 15:3, 15:4, 15:34, 16, 22, 60, etc.; CI Vat Blue 4, 60, etc., and preferably, one or a mixture of two or more selected from the group consisting of CI Pigment Blue 15:3, 15:4, and 60 can be exemplified.

[0035] Examples of magenta pigments include CI Pigment Red 5, 7, 12, 48(Ca), 48(Mn), 57(Ca), 57:1, 112, 122, 123, 168, 184, 202, and CI Pigment Violet 19, and preferably, one or a mixture of two or more pigments selected from the group consisting of CI Pigment Red 122, 202, and 209, and CI Pigment Violet 19. Solid solutions of the above pigments are also acceptable.

[0036] Examples of yellow pigments include CI Pigment Yellow 1, 2, 3, 12, 13, 14C, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 119, 110, 114, 128, 129, 138, 150, 151, 154, 155, 180, and 185. Of these, preferred examples include one or a mixture of two or more selected from the group consisting of CI Pigment Yellow 74, 109, 110, 128, 138, 155, and 180.

[0037] Examples of orange pigments include CI Pigment Orange 36 or 43, or a mixture thereof. Examples of green pigments include CI Pigment Green 7 or 36, or a mixture thereof.

[0038] Luster pigments may also be used, and are not particularly limited as long as they can exhibit luster when attached to a medium. Examples include metal particles of one or more alloys (also called metal pigments) selected from the group consisting of aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, and copper, and pearl pigments with pearly luster. Representative examples of pearl pigments include pigments with pearly luster or interference luster, such as titanium dioxide-coated mica, fish scale foil, and bismuth oxychloride. The luster pigment may also be surface-treated to suppress reaction with water.

[0039] White pigments may also be used, including, for example, metal oxides, barium sulfate, calcium carbonate, and other metal compounds. Examples of metal oxides include titanium dioxide, zinc oxide, silica, alumina, magnesium oxide, and the like. The white pigment may also be particles having a hollow structure.

[0040] The pigments may be used alone or in combination of two or more. From the viewpoint of storage stability such as light resistance, weather resistance, and gas resistance, the pigment is preferably an organic pigment.

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

[0042] The volume average particle size may be measured, for example, using a Nanotrac Series particle distribution analyzer manufactured by Microtrac Bell Co., Ltd. Methods for adjusting the volume average particle size include, for example, adjusting the degree of pulverization of the pigment before dispersion, adjusting the stirring conditions during dispersion (e.g., stirring speed, stirring temperature, etc.), and adjusting by filtration using a filter after dispersion.

[0043] The pigment may be dispersed using a pigment dispersant, or may be dispersed as a self-dispersing pigment by oxidizing or sulfonating the pigment surface with ozone, hypochlorous acid, fuming sulfuric acid, or the like.

[0044] The pigment dispersant has the function of dispersing the pigment in the colored ink composition. The pigment dispersant may be water-soluble, but it is preferable that the pigment dispersant is not completely water-soluble, and that the pigment dispersant is partially or entirely water-soluble. It is believed that the pigment dispersant disperses the pigment by bonding to or adsorbing to the pigment and increasing the hydrophilicity of the pigment surface. The pigment dispersant is preferably a polymer compound, and more preferably a resin. Pigments dispersed with a resin pigment dispersant are also referred to as resin-dispersed pigments.

[0045] Examples of resins for pigment dispersants include 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, vinylnaphthalene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer. In this specification, the term "acrylic resin" refers to a polymer having a skeleton derived from (meth)acrylic acid but not having a skeleton derived from maleic acid or a compound similar thereto.

[0046] Examples of resins for the pigment dispersant include maleic acid-based resins such as styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-maleic acid copolymer, and vinyl acetate-maleic acid ester copolymer, and salts thereof; urethane-based resins and salts thereof, which may or may not have a crosslinked structure; polyvinyl alcohols; and vinyl acetate-crotonic acid copolymers and salts thereof.

[0047] In addition to the polymers of acrylic monomers (acrylic monomers) described above, acrylic resins may also be copolymers of acrylic monomers with other monomers. For example, acrylic vinyl resins, which are copolymers with vinyl monomers as other monomers, are also referred to as acrylic resins. Furthermore, among the styrene resins described above, copolymers of styrene monomers and acrylic monomers are also included in the acrylic resin category. Furthermore, the term acrylic resin also includes its salts and esterified products.

[0048] Commercially available pigment dispersants include, for example, X-200, X-1, X-205, X-220, and X-228 (manufactured by Seiko PMC Co., Ltd.), 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 Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0049] Commercially available acrylic pigment 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.), and the like.

[0050] Commercially available urethane pigment dispersants include BYK-182, BYK-183, BYK-184, and BYK-185 (manufactured by BYK-Chemie Co., Ltd.), TEGO Disperse 710 (manufactured by Evonic Tego Chemi), and Borchi (registered trademark) Gen 1350 (manufactured by OMG Borschers).

[0051] The pigment dispersant may be used alone or in combination of two or more. The total content of the pigment dispersant is 0.1% by mass or more and 30% by mass or less, preferably 5% by mass or more and 25% by mass or less, and more preferably 10% by mass or more and 20% by mass or less, relative to 100% by mass of the colored ink composition. By making the content of the pigment dispersant 0.1% by mass or more, the dispersion stability of the pigment can be improved. Furthermore, if the content of the pigment dispersant is 30% by mass or less, the viscosity of the colored ink composition can be kept low.

[0052] Furthermore, the weight average molecular weight of the pigment dispersant is more preferably at least 500. By using such a pigment dispersant, it is possible to reduce odor and further improve the dispersion stability of the pigment.

[0053] When the pigment is dispersed using a pigment dispersant, the ratio of the pigment to the pigment dispersant is preferably 10:1 to 1:10, and more preferably 4:1 to 1:3.

[0054] The self-dispersing pigment refers to a pigment whose surface has been modified by directly or indirectly bonding to its surface one or more functional groups selected from the group consisting of, for example, a carbonyl group, a carboxyl group, an aldehyde group, a hydroxyl group, a sulfone group, an ammonium group, and salts thereof.

[0055] Examples of self-dispersing pigments include organic pigments such as carbon black, azo lake, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, dioxazine pigments, anthraquinone pigments, nitro pigments, nitroso pigments, and aniline black; and inorganic pigments such as titanium white, zinc white, lead white, carbon black, red iron oxide, vermilion, cadmium red, yellow lead, ultramarine blue, cobalt blue, cobalt purple, and zinc chromate.

[0056] Of these, the self-dispersing pigment is preferably carbon black, from the viewpoint of being able to print black at a high density and having even better ejection reliability.

[0057] The self-dispersing pigment may be a commercially available product or a preparation prepared by a known method, such as "Microjet CW1" and "Microjet CW2" manufactured by Orient Chemical Industry Co., Ltd., or "CAB-O-JET 200" and "CAB-O-JET 300" manufactured by Cabot Corporation.

[0058] (dye) The colored ink composition may contain a dye as a coloring material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, basic dyes, and disperse dyes can be used.

[0059] The content of the colorant is not particularly limited, but is preferably 0.1 to 15 mass % relative to the total amount of the colored ink composition, more preferably 0.5 to 10 mass %, even more preferably 1 to 8 mass %, even more preferably 1.5 to 6 mass %, and particularly preferably 2 to 5 mass %.

[0060] 1.2.1.(2) Water The colored ink composition is a water-based composition. "Water-based" means that the composition contains at least water as a solvent component, and may contain water as a main solvent component.

[0061] Examples of water include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, as well as ultrapure water with reduced ionic impurities. Furthermore, using water that has been sterilized by ultraviolet irradiation or the addition of hydrogen peroxide can suppress the growth of bacteria and fungi when the clear ink composition is stored for a long period of time.

[0062] The content of water in the liquid medium component is preferably 50% by mass or more, more preferably 50 to 100% by mass, and even more preferably 70 to 100% by mass. The content is preferably 90 to 100 mass %, and more preferably 95 to 99 mass %. The liquid medium is a solvent component such as water or an organic solvent.

[0063] The water content is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, and particularly preferably 80% by mass or more, relative to the total mass of the colored ink composition. There is no particular upper limit to the water content, but it is preferably, for example, 99% by mass or less, and even more preferably 95% by mass or less, relative to the total mass of the clear ink composition.

[0064] 1.2.1.(3) Other ingredients (organic solvent) The colored ink composition may contain an organic solvent. Examples of the organic solvent include esters, alkylene glycol ethers, cyclic esters, amides, alcohols, and polyhydric alcohols. Among these, water-soluble organic solvents are more preferred.

[0065] Examples of esters include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, Examples of the glycol monoacetates include propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and methoxybutyl acetate; and glycol diesters include ethylene glycol diacetate, diethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, diethylene glycol acetate butyrate, diethylene glycol acetate propionate, diethylene glycol acetate butyrate, propylene glycol acetate propionate, propylene glycol acetate butyrate, dipropylene glycol acetate butyrate, and dipropylene glycol acetate propionate.

[0066] The alkylene glycol ethers may be monoethers or diethers of alkylene glycol, and alkyl ethers are preferred. Specific examples include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ... alkylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether; and 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 Examples of alkylene glycol dialkyl ethers include alkylene glycol dialkyl ethers such as butyl 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.

[0067] Examples of cyclic esters include cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, β-butyrolactone, β-valerolactone, γ-valerolactone, β-hexanolactone, γ-hexanolactone, δ-hexanolactone, β-heptanolactone, γ-heptanolactone, δ-heptanolactone, ε-heptanolactone, γ-octanolactone, δ-octanolactone, ε-octanolactone, δ-nonalactone, ε-nonalactone, and ε-decanolactone, as well as compounds in which the hydrogen atom of the methylene group adjacent to the carbonyl group of these cyclic esters is substituted with an alkyl group having 1 to 4 carbon atoms.

[0068] Examples of the amides include cyclic amides and non-cyclic amides. Examples of the non-cyclic amides include alkoxyalkyl amides.

[0069] Examples of 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.

[0070] Examples of alkoxyalkylamides include 3-methoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, 3-methoxy-N,N-methylethylpropionamide, 3-ethoxy-N,N-dimethylpropionamide, 3-ethoxy-N,N-diethylpropionamide, 3-ethoxy-N,N-methylethylpropionamide, 3-n-butoxy-N,N-dimethylpropionamide, 3-n-butoxy-N,N-diethylpropionamide, 3-n-butoxy-N,N-methylethylpropionamide, 3-n-propoxy-N,N-dimethylpropionamide, Examples of the propionamide include propionamide, 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, 3-tert-butoxy-N,N-methylethylpropionamide, and N,N-dimethylisobutyric acid amide.

[0071] Examples of alcohols include compounds in which one hydrogen atom of an alkane has been substituted with a hydroxyl group. The alkane preferably has 10 or fewer carbon atoms, more preferably 6 or fewer carbon atoms, and even more preferably 3 or fewer carbon atoms. The alkane has 1 or more carbon atoms, preferably 2 or more carbon atoms. The alkane may be linear or branched. Examples of alcohols include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol, 2-phenoxyethanol, benzyl alcohol, and phenoxypropanol.

[0072] Polyols, also known as polyhydric alcohols, are compounds containing two or more hydroxyl groups in the molecule. Examples include alkanediols and other polyols.

[0073] Examples of alkanediols include compounds in which an alkane is substituted with two hydroxyl groups, such as 1,2-alkanediol, which is a general term for compounds in which hydroxyl groups are substituted at the 1st and 2nd positions of an alkane, and alkanediols other than 1,2-alkanediol.

[0074] Examples of 1,2-alkanediols include ethylene glycol, 1,2-propanediol (propylene glycol), 1,2-butanediol (1,2BD), 1,2-pentanediol (1,2PD), 1,2-hexanediol (1,2HD), 1,2-heptanediol, 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, 3-methyl-1,2-butanediol, 3-methyl-1,2-pentanediol, 4-methyl-1,2-pentanediol, and 3,4-dimethyl-1,2-pentanediol. hexanediol, 3-ethyl-1,2-pentanediol, 4-ethyl-1,2-pentanediol, 3-methyl-1,2-hexanediol, 4-methyl-1,2-hexanediol, 5-methyl-1,2-hexanediol, 3,4-dimethyl-1,2-hexanediol, 3,5-dimethyl-1,2-hexanediol, 4,5-dimethyl-1,2-hexanediol, 3-ethyl-1,2-hexanediol, 4-ethyl-1,2-hexanediol, and 3-ethyl-4-methyl-1,2-hexanediol.

[0075] Other alkanediols include, for example, 1,3-propanediol, 1,3-butylene glycol (also known as 1,3-butanediol), 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2,4-pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, etc. Among the alkanediols, those having 5 or more carbon atoms are preferred, and those having 5 to 10 carbon atoms are more preferred.

[0076] Examples of other polyols include condensates of two or more alkanediol molecules intermolecularly condensed via hydroxyl groups, compounds having three or more hydroxyl groups, etc. Alternatively, other polyols than alkanediols having five or more carbon atoms may be used. That is, examples include alkanediols having four or less carbon atoms, condensates of two or more alkanediol molecules intermolecularly condensed via hydroxyl groups, compounds having three or more hydroxyl groups, etc.

[0077] Examples of condensates in which two or more molecules of alkanediols are intermolecularly condensed via the hydroxyl groups thereof include dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as triethylene glycol and tripropylene glycol.

[0078] The compound having three or more hydroxyl groups is a compound having an alkane or polyether structure as a backbone and having three or more hydroxyl groups, such as glycerin, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, and polyoxypropylenetriol.

[0079] The organic solvents may be used alone or in combination of two or more.

[0080] When the colored ink composition contains an organic solvent, the content of the organic solvent is determined based on the total quality of the colored ink composition. The total amount is preferably 1% by mass or more, more preferably 1% by mass or more and 40% by mass or less, even more preferably 3% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and particularly preferably 7% by mass or more and 20% by mass or less.

[0081] The content of polyhydric alcohols may be within the above range, and the content of alkanediols may be within the above range, and the content of alkanediols having 5 or more carbon atoms may be within the above range. Furthermore, the content of alkanediols having 5 or more carbon atoms is preferably 0.5% by mass or more, more preferably 1% by mass or more and 20% by mass or less, even more preferably 2% by mass or more and 15% by mass or less, and even more preferably 3% by mass or more and 10% by mass or less, relative to the total mass of the colored ink composition.

[0082] (surfactant) The colored ink composition may contain a surfactant. The surfactant is not particularly limited, but examples thereof include acetylene glycol surfactants, fluorine-based surfactants, and silicone-based surfactants.

[0083] 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 Japan Co., Ltd.), and Examples include Lulfin 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, and AE-3 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), and Acetylenol E00, E00P, E40, and E100 (all trade names, manufactured by Kawaken Fine Chemicals Co., Ltd.).

[0084] As the fluorine-based surfactant, it is preferable to use a fluorine-modified polymer, and a specific example thereof is BYK-340 (trade name, manufactured by BYK Japan KK).

[0085] 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 exemplified. Commercially available polyether-modified organosiloxanes include, for example, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, and BYK-348 (all trade names, manufactured by BYK Japan KK), 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-6012, KF-6015, and KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), and Silface SAG503A and Silface SAG014 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.).

[0086] The surfactants may be used alone or in combination of two or more. Among the surfactants listed above, those that function as defoamers may also be used. Examples of such packaging materials include Surfynol DF110D (trade name, manufactured by Air Products Japan Co., Ltd.).

[0087] When surfactants are contained, the content thereof is preferably 0.1% by mass or more and 1.5% by mass or less in total relative to the total mass of the inkjet ink composition.

[0088] (resin) The colored ink composition may contain a resin. Examples of resins include urethane-based resins, acrylic-based resins (including styrene-acrylic-based resins), fluorene-based resins, polyolefin-based resins, rosin-modified resins, terpene-based resins, polyester-based resins, polyamide-based resins, epoxy-based resins, vinyl chloride-based resins, vinyl chloride-vinyl acetate copolymers, and ethylene-vinyl acetate-based resins. Among these, urethane-based resins, acrylic-based resins, polyolefin-based resins, and polyester-based resins are preferred. These resins may be water-soluble resins or resin particles, but are preferably in the form of resin particles. Resin particles are often handled in the form of an emulsion, but may also be in the form of a powder. Furthermore, the resins may be used alone or in combination of two or more.

[0089] Urethane resin is a general term for resins having urethane bonds. In addition to urethane bonds, the urethane resin may be a polyether urethane resin containing ether bonds in the main chain, a polyester urethane resin containing ester bonds in the main chain, or a polycarbonate urethane resin containing carbonate bonds in the main chain. Furthermore, commercially available products may be used as the urethane resin, and examples thereof include Superflex 210, 460, 460s, 840, and E-4000 (trade names, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Rezamin D-1060, D-2020, D-4080, D-4200, D-6300, and D-6455 (trade names, manufactured by Dainichiseika Color & Chemicals Mfg. 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 Permarin UA-150 (trade name, manufactured by Sanyo Chemical Industries, Ltd.).

[0090] 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. Examples include resins obtained from acrylic monomers and copolymers of acrylic monomers with other monomers. Examples include acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers. Another example of a vinyl monomer is styrene.

[0091] Examples of acrylic monomers that can be used include acrylamide and acrylonitrile. Commercially available products may be used for the resin emulsion using an acrylic resin as a raw material, such as FK-854 (trade name, manufactured by Chuo Rika Kogyo Co., Ltd.), Mowinyl 6969D, 6899D, 952B, and 718A (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and Nipol LX852 and LX874 (trade names, manufactured by Nippon Zeon Co., Ltd.).

[0092] In this specification, the acrylic resin may be a styrene-acrylic resin, which will be described later.

[0093] Styrene-acrylic resins are copolymers obtained from styrene monomer and (meth)acrylic monomer, and examples include styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, and styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer. As the styrene-acrylic resin, commercially available products may be used, such as JONCRYL 62J, 7100, 390, 711, 511, 7001, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, and 7610 (trade names, manufactured by BASF), Mowinyl 966A and 975N (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and Vinyblan 2586 (manufactured by Nissin Chemical Industry Co., Ltd.).

[0094] Polyolefin resins are made up of olefins such as ethylene, propylene, and butylene as their structural skeletons. As the olefin resin, commercially available products can be used, such as Arrowbase CB-1200 and CD-1200 (trade names, manufactured by Unitika Ltd.).

[0095] The resin may also be supplied in the form of an emulsion. Examples of commercially available resin emulsions include Microgel E-1002 and E-5002 (trade names of Nippon Paint Co., Ltd., styrene-acrylic resin emulsions), Boncoat 4001 (trade name of DIC Corporation, acrylic resin emulsion), Boncoat 5454 (trade 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 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) (trade name, manufactured by Showa Denko K.K.), Polysol SAE1014 (trade name, styrene-acrylic resin emulsion, manufactured by Zeon Co., Ltd.), Saivinol SK-200 (trade name, acrylic resin emulsion, manufactured by Saiden Chemical Co., Ltd.), AE -120A (trade name of JSR Corporation, acrylic resin emulsion), AE373D (trade name of E-Tech Corporation, carboxy-modified styrene-acrylic resin emulsion), Seikadyne 1900W (trade name of Dainichiseika Color & Chemicals Mfg. Co., Ltd., ethylene-vinyl acetate resin emulsion), Vinyblan 2682 (acrylic resin emulsion), Vinyblan 2886 (vinyl acetate-acrylic resin emulsion), Vinyblan 5202 (acetic acid acrylic resin emulsion) (trade name of Nissin Chemical Industry Co., Ltd.), Elitel KA-5071S, KT-8803, KT-9204, KT-8701, KT -8904, KT-0507 (trade name of Unitika Ltd., polyester resin emulsion), Hi-Tec SN-2002 (trade name of Toho Chemical Co., Ltd., polyester resin emulsion), Takelac W-6020, W-635, W-6061, W-605, W-635, W-6021 (trade name of Mitsui Chemicals Polyurethanes, urethane resin emulsion), Superflex 210, 870, 800, 150, 420, 460, 470, 610, 700 (trade name of Daiichi Kogyo Seiyaku Co., Ltd., urethane resin emulsion), Parmarin UA-150 (trade name of Sanyo Chemical Industries, Ltd.,Urethane resin emulsion), Sancure 2710 (manufactured by Lubrizol Japan, urethane resin emulsion), NeoRez R-9660, R-9637, R-940 (manufactured by Kusumoto Chemicals Co., Ltd., urethane resin emulsion), Adeka Bontitor HUX-380, 290K (manufactured by ADEKA Corporation, urethane resin emulsion), Mowinyl 966A, Mowinyl 7320 (manufactured by 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-7 The binder may be selected from 630A, 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), and the like.

[0096] The glass transition temperature Tg of the resin is preferably 0° C. or higher, more preferably 30° C. or higher, even more preferably 50° C. or higher, particularly preferably 60° C. or higher, and even more particularly preferably 70° C. or higher. When the glass transition temperature Tg of the resin is particularly 60° C. or higher, the dry friction resistance tends to be better. The clogging recovery property also tends to be better.

[0097] The upper limit of the glass transition temperature Tg of the resin is not particularly limited, but is preferably 150°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower.

[0098] 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 (measurement method for glass transition temperature of plastics).

[0099] The resin content, as solid content, relative to the total mass of the colored ink composition, is preferably from 0.1% to 20% by mass, more preferably from 1.0% to 15.0% by mass, even more preferably from 2.0% to 10.0% by mass, and particularly preferably from 3.0% to 8.0% by mass.

[0100] (wax) The colored ink composition may contain a wax. Examples of the wax include those that dissolve in the ink and those that are dispersed in the form of fine particles, such as an emulsion. By using such a wax, a recorded matter with superior abrasion resistance tends to be obtained.

[0101] The wax is not particularly limited, but examples thereof include ester waxes of higher fatty acids and higher monohydric or dihydric alcohols, paraffin wax, microcrystalline wax, polyolefin wax, and mixtures thereof.

[0102] Examples of polyolefin waxes include waxes and copolymers thereof made from olefins such as ethylene, propylene, and butylene, or derivatives thereof, specifically polyethylene waxes, polypropylene waxes, polybutylene waxes, etc. Commercially available polyolefin waxes can be used, specifically, NOPCOT PEM17 (trade name, manufactured by San Nopco Ltd.), CHEMIPEARL W4005 (trade name, manufactured by Mitsui Chemicals, Inc.), AQUACER 515, AQUACER 539, AQUACER 593 (all trade names, manufactured by BYK Japan), and HI-TECH E7100S, E-6314, E-6500 (manufactured by Toho Chemical Industry Co., Ltd., polyethylene waxes).

[0103] When a wax is contained, the content of the wax is preferably from 0.1 to 5% by mass, more preferably from 0.2 to 4% by mass, and even more preferably from 0.3 to 3% by mass, relative to the total mass of the colored ink composition. A wax content within this range is preferred because it tends to improve abrasion resistance, maintain low ink viscosity, and provide excellent ejection stability and clogging recovery.

[0104] (Other substances) The colored ink composition may contain, as necessary, pH adjusters, sugars, ureas, chelating agents, preservatives, antifungal agents, rust inhibitors, and the like.

[0105] The pH adjuster is not particularly limited, and examples thereof include an appropriate combination of an acid, a base, a weak acid, and a weak base. Examples of the acid and base used in such a combination include inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid, inorganic bases such as lithium hydroxide, sodium hydroxide, potassium hydroxide, potassium dihydrogen phosphate, disodium hydrogen phosphate, potassium carbonate, sodium carbonate, sodium bicarbonate, and ammonia, and organic bases such as triethanolamine, diethanolamine, monoethanolamine, tripropanolamine, triisopropanolamine, diisopropanolamine, tris(2-methyl-2-methyl-2-propanol), and the like. Examples of suitable organic acids include adipic acid, citric acid, succinic acid, lactic acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), morpholinoethanesulfonic acid (MES), carbamoylmethyliminobisacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamido)-2 Other examples of suitable buffers include Good's buffers such as N-aminoethanesulfonic acid (ACES), cholamine hydrochloride, N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), acetamidoglycine, tricine, glycinamide, and bicine, as well as phosphate buffers, citrate buffers, and Tris buffers. Furthermore, among these, it is preferable to use, as part or all of the pH adjuster, tertiary amines such as triethanolamine and triisopropanolamine, and carboxyl group-containing organic acids such as adipic acid, citric acid, succinic acid, and lactic acid, since this allows for a more stable pH buffering effect.

[0106] Examples of ureas include urea, ethylene urea, tetramethyl urea, thiourea, 1,3-dimethyl-2-imidazolidinone, and the like, and betaines (trimethylglycine, triethylglycine, tripropylglycine, triisopropylglycine, N,N,N-trimethylalanine, N,N,N-triethylalanine, N,N,N-triisopropylalanine, N,N,N-trimethylmethylalanine, carnitine, acetylcarnitine, and the like).

[0107] Specific examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0108] Examples of chelating agents include ethylenediaminetetraacetic acid and salts thereof (disodium dihydrogen ethylenediaminetetraacetate, or nitrilotriacetate, hexametaphosphate, pyrophosphate, or metaphosphate of ethylenediamine, etc.).

[0109] Examples of preservatives and antifungal agents include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel IB, and Proxel TN (all trade names manufactured by Lonza Japan), and 4-chloro-3-methylphenol (such as Preventol CMK manufactured by Bayer).

[0110] Examples of the rust inhibitor include benzotriazole, acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, etc. Among these, benzotriazole is particularly preferred.

[0111] Examples of other additives include viscosity adjusters, antifungals, antioxidants, antireducing agents, oxygen absorbers, ultraviolet absorbers, and dissolution aids, and the like, and the composition may contain at least one of these.

[0112] 1.2.1.(4) Manufacturing and Properties The colored ink composition can be obtained by mixing the above-described components in any order and, if necessary, removing impurities by filtration or the like. A suitable method for mixing the components is to sequentially add the materials to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stir and mix them. As a filtration method, centrifugal filtration, filter filtration, or the like can be performed as necessary.

[0113] From the viewpoint of a balance between image quality and reliability as an ink for inkjet recording, the colored ink composition preferably has a surface tension (static surface tension) at 20°C of 18 mN / m or more and 40 mN / m or less, and more preferably 20 mN / m or more and 35 mN / m or less. The surface tension can be measured, for example, by using an automatic surface tensiometer CBVP-Z (trade name, manufactured by Kyowa Interface Science Co., Ltd.) to check the surface tension when a platinum plate is wetted with ink in an environment of 20°C.

[0114] It is more preferable to adjust the surface tension of the colored ink composition so that the difference between the surface tension of the colored ink composition and the surface tension of the clear ink composition described below is 2 mN / m or less. This can further prevent the colored ink composition from transferring to non-image areas where the colored ink composition is not applied.

[0115] The viscosity of the colored ink composition at 20°C is preferably 3 mPa·s or more and 10 mPa·s or less, and more preferably 3 mPa·s or more and 8 mPa·s or less. The viscosity can be measured at 20°C using, for example, a viscoelasticity tester MCR-300 (trade name, manufactured by Pysica).

[0116] 1.2.2. Mode of attachment The ink deposition process is performed by an inkjet method. The area to which the colored ink composition is deposited in the ink deposition process is referred to as the image area. The ink deposition process and the clear ink deposition process described below may be performed first or simultaneously on a predetermined area of ​​the recording medium. However, if the clear ink composition is deposited after the colored ink composition is deposited on the image area, a better effect of suppressing bleeding can be expected. In this case, the time required for recording increases. Therefore, it is more preferable not to deposit the clear ink composition on the image area, or to deposit the clear ink composition on the image area in an amount smaller than the amount of clear ink composition deposited on the non-image area. In either case, if the clear ink composition is deposited on the non-image area simultaneously with the deposition of the colored ink composition on the image area, the time required for recording does not increase.

[0117] The amount of the colored ink composition applied in the ink application step was 15 g / m 2More than 120g / m 2 Less than 30 g / m 2 More than 80g / m 2 Less than 30 g / m is more preferable. 2 More than 60g / m 2 The following is even more preferred:

[0118] Also, 3 to 15 mg / inch 2 It is preferable that the coating amount range is 5 to 10 m / inch. 2 It is also preferable that the maximum adhesion amount of the color ink composition during recording is within the above range.

[0119] 1.3.Clear ink application process In the clear ink application step, an aqueous clear ink composition is ejected from an inkjet head and applied to a recording medium, and the clear ink composition is applied to non-image areas of the recording medium other than the image areas where the colored ink compositions are applied.

[0120] 1.3.1. Clear ink composition The clear ink composition of this embodiment is an aqueous composition that contains a resin and a wax, and does not contain more than 0.5% by mass of an organic solvent, which is a polyol with a normal boiling point of 280°C or higher, relative to the total mass of the clear ink composition. The clear ink composition is an ink composition that is not used to color a recording medium, such as a colored ink composition. Therefore, the content of the colorant in the clear ink composition is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, even more preferably 0.01% by mass or less, and may even be 0% by mass. The clear ink composition may have a composition similar to that which may be used in the above-mentioned colored ink composition, except for the colorant.

[0121] 1.3.1.(1) Resin The clear ink composition contains a resin. The type of resin is the same as that described above in the colored ink composition section, and detailed description thereof will be omitted.

[0122] The resin content in the clear ink composition is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1.0% by mass or more and 15.0% by mass or less, even more preferably 2.0% by mass or more and 10.0% by mass or less, and particularly preferably 3.0% by mass or more and 8.0% by mass or less, in terms of solid content, relative to the total mass of the clear ink composition.

[0123] Furthermore, the content of the resin in the clear ink composition, the total content of the resin and the wax contained in the clear ink composition, is preferably from 3 to 15% by mass, more preferably from 4 to 10% by mass, and even more preferably from 5 to 19% by mass, relative to the total mass of the clear ink composition. This makes it possible to further suppress color transfer of the colored ink composition to non-image areas.

[0124] Furthermore, the mass ratio of the resin to the wax (wax / resin) contained in the clear ink composition is preferably 0.15 or more, more preferably 0.2 or more, even more preferably 0.25 or more, and even more preferably 0.33 or more. It is also preferably 0.8 or less, more preferably 0.6 or less, and even more preferably 0.4 or less. This further suppresses color transfer of the colored ink composition to non-image areas.

[0125] 1.3.1.(2) Wax The clear ink composition contains a wax. The type, content, etc. of the wax are the same as those described above in the section on the colored ink composition, and detailed description thereof will be omitted.

[0126] The wax contained in the clear ink composition preferably has a melting point of 115°C or higher, more preferably 120°C or higher, and even more preferably 125°C or higher. There is no particular upper limit to the melting point of the wax contained in the clear ink composition, but it is preferably 160°C or lower, more preferably 140°C or lower, and even more preferably 130°C or lower. Furthermore, the wax contained in the clear ink composition is more preferably a polyolefin wax, and is preferably selected from polypropylene, polyethylene, copolymers thereof, and the like. This can further suppress color transfer of the colored ink composition to non-image areas.

[0127] The wax contained in the clear ink composition preferably has a volume average particle diameter (D50) of 40 nm or more, more preferably 50 nm or more, and even more preferably 60 nm or more. The upper limit of the volume average particle diameter (D50) of the wax contained in the clear ink composition can be any value within the range applicable to the inkjet method, but is, for example, 200 nm or less, preferably 100 nm or less. This makes it easier to smooth out unevenness on the surface of the recording medium, further suppressing color transfer of the colored ink composition to non-image areas.

[0128] The wax content in the clear ink composition is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1.0% by mass or more and 15.0% by mass or less, even more preferably 2.0% by mass or more and 10.0% by mass or less, and particularly preferably 3.0% by mass or more and 8.0% by mass or less, in terms of solid content, relative to the total mass of the clear ink composition.

[0129] 1.3.1.(3) Water The clear ink composition is a water-based composition. "Water-based" means that it contains at least water as a solvent component, and may contain water as the main solvent component. The water is the same as described above in the section on colored ink compositions, and a detailed description thereof will be omitted.

[0130] 1.3.1.(4) Polyols The clear ink composition does not contain 0.5% by mass or more of organic solvents that are polyols with a normal boiling point of 280° C. or higher, relative to the total mass of the clear ink composition. The polyols are the same as those described above in the section on colored ink compositions, and a detailed description of them will be omitted.

[0131] Examples of polyols with a normal boiling point of 280°C or higher include glycerin. The content of organic solvents that are polyols with a normal boiling point of 280°C or higher is preferably 0.3% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, relative to the total mass of the clear ink composition, and particularly preferably zero (0% by mass).

[0132] 1.3.1.(5) Other ingredients The clear ink composition may contain the same components as those described in the section "1.2.1.(3) Other Components" except for the polyols having a normal boiling point of 280°C or higher. The other components that may be contained in the clear ink composition can be explained by replacing "colored ink composition" in that section with "clear ink composition."

[0133] 1.3.1.(6) Manufacturing and Properties The clear ink composition can be obtained by mixing the above-mentioned components in any order and, if necessary, removing impurities by filtration or the like. A suitable method for mixing the components is to sequentially add the materials to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stir and mix them. As a filtration method, centrifugal filtration, filter filtration, or the like can be used as necessary.

[0134] From the viewpoint of balancing image quality and reliability as an inkjet recording ink, the clear ink composition preferably has a surface tension (static surface tension) of 18 mN / m to 40 mN / m at 20°C, more preferably 20 mN / m to 35 mN / m, and even more preferably 22 mN / m to 33 mN / m. Note that the surface tension can be measured, for example, using an automatic surface tensiometer CBVP-Z (trade name, manufactured by Kyowa Interface Science Co., Ltd.) by checking the surface tension when a platinum plate is wetted with the ink in an environment of 20°C.

[0135] It is more preferable to adjust the surface tension of the clear ink composition so that the difference between the surface tension of the clear ink composition and the surface tension of the colored ink composition is 2 mN / m or less, which can further suppress color transfer of the colored ink composition to non-image areas where the colored ink composition is not applied.

[0136] The viscosity of the clear ink composition at 20°C is preferably 3 mPa·s or more and 10 mPa·s or less, and more preferably 3 mPa·s or more and 8 mPa·s or less. The viscosity can be measured at 20°C using, for example, a viscoelasticity tester MCR-300 (trade name, manufactured by Pysica).

[0137] 1.3.2. Mode of attachment The clear ink applying step is carried out by an ink jet method. In the clear ink applying step, the clear ink composition is applied to at least the non-image area, which is an area other than the image area. Note that the clear ink composition may be applied to the image area. The timing of performing the ink application step and the clear ink application step is as already described.

[0138] The amount of the clear ink composition applied in the clear ink application step was 15 g / m 2 More than 120g / m 2 Less than 30 g / m 2 More than 80g / m 2Less than 30 g / m is more preferable. 2 More than 60g / m 2 The following is even more preferred:

[0139] The amount of clear ink attached to the non-image area is 0.1 to 7 mg / inch. 2 is preferable, and 0.5 to 5 m / inch 2 More preferably, 0.8 to 3 mg / inch 2 is more preferable, and 1 to 2 m / inch 2 is particularly preferred.

[0140] The amount of clear ink attached to the image area is 0.1 to 7 mg / inch. 2 is preferable, and 0.3 to 5 m / inch 2 More preferably, 0.5 to 2 mg / inch 2 is more preferable, and 0.6 to 1 m / inch 2 is particularly preferred.

[0141] 1.4. Relationship between image and non-image areas In the recording method of this embodiment, the total amount of resin and wax contained in the clear ink composition attached to the non-image area is 0.6 mg / inch. 2 Preferably, it is 0.4 mg / inch or less. 2 More preferably, it is 0.3 mg / inch or less. 2 More preferably, it is 0.2 mg / inch or less. 2 It is even more preferable that the following is satisfied: By doing so, color transfer of the color ink composition to non-image areas can be sufficiently suppressed.

[0142] In the recording method of this embodiment, the region in the non-image area where the clear ink composition is applied preferably includes an area extending 2 cm or more from the peripheral edge of the image area, more preferably an area extending 3 cm or more from the peripheral edge of the image area, and even more preferably an area extending 5 cm or more from the peripheral edge of the image area. In other words, when focusing on a certain image area in the recording area where recording is performed in the recording method, the region where the clear ink composition is applied preferably includes an area extending a predetermined length or more from the peripheral edge of the image area.

[0143] It is particularly preferable that the area in the non-image area to which the clear ink composition is applied is the entire non-image area; however, even if the area is not the entire non-image area, color transfer of the colored ink composition to the non-image area can be suppressed.

[0144] Furthermore, in the recording method of this embodiment, it is also preferable that the amount of clear ink composition attached to an image area adjacent to a non-image area to which the clear ink composition has been attached is equal to or less than the amount of clear ink composition attached to the non-image area. Even in this manner, color transfer of the colored ink composition to the non-image area can be suppressed. The reason for this is that, in this recording method, attaching a clear ink composition to the image area is effective, but is not considered essential. This can be inferred from the fact that the surface of the recording medium is rough, and although the colored ink composition is transferred by rubbing the image area, ink peeling in the image area is not noticeable even after transfer, while staining in the non-image area is noticeable. On the other hand, if the clear ink composition is attached to the image area, depending on the amount of attachment, the total amount of attachment in the image area may increase, which may result in bleeding in the image area.

[0145] 1.5. Effects, etc. According to the recording method of this embodiment, it is possible to obtain a recorded matter that can suppress color transfer of the color ink composition to non-image areas, even when the substrate is a non-absorbent or low-absorbent recording medium having an in-plane surface roughness (Sa) of 0.2 μm or more.

[0146] 1.6.Other processes The recording method according to this embodiment may include the following steps in addition to the ink application step and the clear ink application step.

[0147] (Primary drying process) The recording method according to this embodiment may include a primary drying step in which the composition applied to the recording medium is dried by a drying mechanism. The primary drying step is a step in which the recording medium is heated before each application step, or heated or air is blown onto the recording medium during each application step or soon after application of the ink to the recording medium, thereby quickly drying the ink.

[0148] The primary drying step is a step for drying at least a part of the solvent component of the composition adhered to the recording medium to at least an extent that the fluidity of the composition is reduced. The primary drying step may be performed by adhering the composition to a heated recording medium, or may be performed early after the composition is adhered to the recording medium to promote drying.

[0149] In the primary drying step, it is preferable that the droplets of the composition that have landed on the recording medium start to dry within 0.5 seconds at the latest after landing. The drying unit (drying mechanism) for drying the composition on the recording medium is not particularly limited, and examples thereof include a platen heater, a hot air heater, an IR heater, etc., which have a heating function, and a blower, etc., which do not have a heating function.

[0150] There are several types of drying mechanisms, including a conduction type, which heats the recording medium by conducting heat from a member that comes into contact with the recording medium to the recording medium, a radiation type, which heats the recording medium by radiating IR or other radiation to the recording medium, and a blowing type, which blows air toward the recording medium.

[0151] The air blowing method includes a method of blowing hot air onto the recording medium while also heating it, and a method of using room temperature air to promote drying of the ink without heating. Methods that do not involve heating are preferred because they can prevent the ink in the nozzles of the inkjet head from drying out and reducing ejection stability. It is also preferred to use either the conduction method or the radiation method in combination with the air blowing method. When using both methods in combination, the air blowing method may also be a method that does not involve heating.

[0152] In the primary drying step, the surface temperature of the recording medium is preferably 60°C or less, more preferably 55°C or less. Furthermore, it is preferably 40°C or less, even more preferably 35°C or less, and particularly preferably 30°C or less. On the other hand, it is preferably 20°C or more, more preferably 25°C or more. Furthermore, it is preferably 30 to 50°C, even more preferably 40 to 45°C. Even more preferably, it is 25 to 28°C.

[0153] By keeping the surface temperature of the recording medium within the above range, the drying property is improved, and the abrasion resistance of the resulting recorded matter tends to be improved. In addition, the clogging recovery property, ejection stability, and color development are also excellent, which is preferable.

[0154] It is also possible to omit the primary drying step or to omit a step involving heating as the primary drying step, and in this case too, the surface temperature of the recording medium on the platen should be kept below the above range.

[0155] When using a blower, the wind speed near the recording medium is preferably 0.2 m / s or more, and 20 m / s or less. It is further preferably 0.5 to 10 m / s, more preferably 1 to 5 m / s, and even more preferably 2 to 3 m / s. The wind temperature is preferably 45°C or less, more preferably 40°C or less, even more preferably 32°C or less, and particularly preferably 20 to 27°C.

[0156] (Secondary heating process) The recording method according to this embodiment may include a heating step (secondary heating step) of heating the recording medium to which the colored ink composition and the clear ink composition have been applied. The secondary heating step is a step of heating the recording medium sufficiently to complete the recording and enable the recorded material to be used. The secondary heating step is also a step of sufficiently drying the solvent component of the ink and heating the resin contained in the ink to form a flat ink coating.

[0157] The secondary heating step is preferably initiated more than 0.5 seconds after the ink is applied to the recording medium, for example, it is preferable to start heating a certain recording area of ​​the recording medium more than 0.5 seconds after the ink has been completely applied to that area.

[0158] The surface temperature of the recording medium in the secondary heating step is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher. In the secondary heating step, heating the recording medium to a surface temperature of 60°C or higher tends to provide excellent drying properties and better wet friction resistance. The upper limit is preferably 100°C or lower, and more preferably 90°C or lower.

[0159] The secondary heating mechanism may be a conduction type, a radiation type, or an air blower type.

[0160] 2. Recording device The recording apparatus according to this embodiment is a recording apparatus that performs the above-described recording method, and includes the above-described colored ink composition, the above-described clear ink composition, and an inkjet head that ejects the colored ink composition and the clear ink composition.

[0161] An example of a recording apparatus suitable for the recording method according to this embodiment will be described below with reference to the drawings.

[0162] FIG. 1 is a schematic cross-sectional view showing an inkjet recording apparatus 1. FIG. 2 is a perspective view showing an example of the configuration of the periphery of the carriage of the inkjet recording apparatus 1 of FIG. 1. As shown in FIGS. 1 and 2, the inkjet recording apparatus 1 includes an inkjet head 2, an IR heater 3, a platen heater 4, a heating heater 5, a cooling fan 6, a preheater 7, a ventilation fan 8, a carriage 9, a platen 11, a carriage movement mechanism 13, a transport means 14, and a control unit CONT. The operation of the entire inkjet recording apparatus 1 is controlled by the control unit CONT shown in FIG. 2.

[0163] The inkjet head 2 has an inkjet head 2a that ejects a colored ink composition and an inkjet head 2b that ejects a clear ink composition, and recording can be performed on the recording medium M by ejecting and depositing the colored ink composition and the clear ink composition from the nozzles of the respective inkjet heads.

[0164] In this embodiment, the inkjet head 2 is a serial inkjet head that scans multiple times in the main scanning direction relative to the recording medium M to deposit the colored ink composition and the clear ink composition onto the recording medium M. The inkjet head 2 is mounted on a carriage 9 shown in FIG. 2. The inkjet head 2 is scanned multiple times in the main scanning direction relative to the recording medium M by the operation of a carriage movement mechanism 13 that moves the carriage 9 in the medium width direction of the recording medium M. The medium width direction is the main scanning direction of the inkjet head 2. Scanning in the main scanning direction is also called main scanning.

[0165] 3, the inkjet head 2a that ejects the colored ink composition and the inkjet head 2b that ejects the clear ink composition are arranged in a direction parallel to the conveyance direction (direction T2) of the recording medium M. The inkjet head 2a and the inkjet head 2b are arranged side by side at the same position. When projected in the main scanning direction, the inkjet head 2a and the inkjet head 2b have a portion where they overlap in the transport direction (direction T2).

[0166] For example, with this arrangement, the colored ink composition and the clear ink composition can be applied simultaneously to the recording medium (second application mode). That is, the colored ink composition and the clear ink composition are applied to the recording medium in the same main scanning region by the same main scanning. In this case, when the clear ink is applied to the image area, the colored ink composition and the clear ink composition are applied to the recording medium in the same main scanning region by the same main scanning, overlapping each other.

[0167] The nozzle rows shown in FIG. 3 are nozzle rows that eject ink in each inkjet head.

[0168] 4 shows an arrangement in which the inkjet head 2b that ejects the clear ink composition is arranged downstream of the inkjet head 2a that ejects the colored ink composition in the transport direction (direction T2) of the recording medium M. When projected in the main scanning direction, the inkjet head 2a and the inkjet head 2b do not have any overlapping positions in the transport direction (direction T2).

[0169] For example, with this arrangement, the colored ink composition and the clear ink composition can be deposited in this order on the recording medium, in a mode (first deposition mode) in which the colored ink composition and the clear ink composition are layered on top of each other. That is, the colored ink composition is deposited in a main scanning region by a certain main scanning pass, and the clear ink composition is deposited in the same main scanning region by a main scanning pass subsequent to that main scanning pass. In this case, when depositing the clear ink in the image area, the colored ink composition is deposited in the main scanning region by a certain main scanning pass, and the clear ink composition is deposited in a layered manner in the main scanning region by a main scanning pass subsequent to that main scanning pass.

[0170] The nozzle rows shown in FIG. 4 are nozzle rows that eject ink in each inkjet head.

[0171] Here, the main scanning direction is the direction in which the carriage 9 carrying the inkjet head 2 moves. In FIG. 1, this direction intersects with the sub-scanning direction, which is the transport direction of the recording medium M, indicated by the arrow SS. In FIG. 2, the width direction of the recording medium M, i.e., 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. Note that a single scan is performed in the main scanning direction, i.e., in either the direction indicated by the arrow S1 or the arrow S2. Recording is performed on the recording medium M by repeatedly performing the main scan of the inkjet head 2 and the sub-scan, which transports the recording medium M, multiple times. In other words, the color ink application process and the clear ink application process are performed by multiple main scans in which the inkjet head 2 moves in the main scanning direction and multiple sub-scans in which the recording medium M moves in the sub-scanning direction that intersects the main scanning direction.

[0172] The cartridges 12 that supply each ink to the inkjet head 2 include a plurality of independent cartridges. The cartridges 12 are detachably mounted on a carriage 9 that carries the inkjet head 2. Each of the plurality of cartridges can be filled with a different type of ink, and ink is supplied from the cartridges 12 to each nozzle. Note that, although this embodiment shows an example in which the cartridges 12 are mounted on the carriage 9, this is not limiting, and the cartridges 12 may be provided in a location other than the carriage 9 and ink may be supplied to each nozzle by a supply pipe (not shown).

[0173] A conventionally known method can be used for ejection from the inkjet head 2. In this embodiment, a method of ejecting droplets using the vibration of a piezoelectric element, that is, an ejection method of forming ink droplets by mechanical deformation of an electrostrictive element, is used.

[0174] The inkjet recording apparatus 1 is equipped with a ventilation fan 8, an IR heater 3, and a platen heater 4 for drying ink ejected from the inkjet head 2 and attached to the recording medium M. The primary drying step can be performed by appropriately combining the ventilation fan 8, the IR heater 3, and the platen heater 4. In the primary drying step, it is not always necessary to heat the recording medium M, and the ventilation fan 8 may be used alone to blow air at room temperature.

[0175] Note that by using the IR heater 3, the recording medium M can be radiatively heated by radiating infrared rays from the inkjet head 2 side. This makes it easier for the inkjet head 2 to be heated at the same time, but compared to heating from the back side of the recording medium M using a platen heater 4 or the like, the temperature can be increased without being affected by the thickness of the recording medium M. Also, various fans (for example, ventilation fan 8) may be provided to blow warm air or air at the same temperature as the environment onto the recording medium M to dry the ink on the recording medium M.

[0176] The platen heater 4 can heat the recording medium M via the platen 11 at a position facing the inkjet head 2 so that the ink ejected by the inkjet head 2 can dry quickly from the moment it is applied to the recording medium M. The platen heater 4 can heat the recording medium M by conduction, thereby allowing the ink to be applied to the heated recording medium M.

[0177] The surface temperature of the recording medium M heated by the IR heater 3 and the platen heater 4 is preferably within the range described in the above primary drying step.

[0178] The heater 5 dries and solidifies the ink attached to the recording medium M, i.e., it is a heater for secondary heating. The heater 5 can be used in the secondary heating step. When the heater 5 heats the recording medium M on which an image has been recorded, the moisture contained in the ink evaporates and dissipates more quickly, and an ink film is formed by the resin contained in the clear ink composition. In this way, the ink film is firmly fixed or adhered to the recording medium M, providing excellent film-forming properties, and an excellent, high-quality image can be obtained in a short period of time.

[0179] The surface temperature of the recording medium M heated by the heater 5 is preferably within the range described in the above-mentioned secondary heating step. When the temperature is within the above-mentioned range, a high-quality image tends to be obtained in a short time.

[0180] The inkjet recording apparatus 1 may have a cooling fan 6. After the ink recorded on the recording medium M has dried, the ink on the recording medium M is cooled by the cooling fan 6, thereby forming an ink coating film on the recording medium M with good adhesion.

[0181] The inkjet recording apparatus 1 may also include a preheater 7 that preheats the recording medium M before the ink is applied to the recording medium M. Furthermore, the inkjet recording apparatus 1 may also include a ventilation fan 8 so that the ink applied to the recording medium M dries more efficiently.

[0182] 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 relative to the recording medium M, and a conveying means 14 that is a roller that conveys the recording medium M in the sub-scanning direction. The operation of 4 is controlled by the control unit CONT.

[0183] In another embodiment, the inkjet recording apparatus may be a line-type inkjet recording apparatus in which the inkjet head 2 is a line head. For example, in FIG. 1, the inkjet head 2 is a line head having a length equal to or greater than the recording width in the width direction of the recording medium, and is fixed in position. Ink is ejected from the inkjet head 2 toward the conveyed recording medium M and adheres to the recording medium. In this case, recording is performed by one main scan. When the inkjet head 2 is a line head, the rest of the configuration may be the same as in the serial type described above.

[0184] According to the recording apparatus of this embodiment, it is possible to obtain a recorded matter that can suppress color transfer of the color ink composition to non-image areas, even when the substrate is a non-absorbent recording medium or a low-absorbent recording medium having an in-plane surface roughness (Sa) of 0.2 μm or more.

[0185] 3. Examples and Comparative Examples The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" and "%" are based on mass. The evaluations were carried out in an environment of a temperature of 25.0°C and a relative humidity of 40.0%, unless otherwise specified.

[0186] 3.1. Preparation of each ink The components were placed in a container so as to obtain the compositions shown in Tables 1 and 2, and mixed thoroughly for two hours using a magnetic stirrer. After stirring for one hour, the mixture was filtered using a 5.0 μm PTFE membrane filter to obtain colored ink (B1) and clear inks (CL1 to CL16). Pure water was used.

[0187] The details of each component in Tables 1 and 2 are as follows: Pigment, fixing resin, and wax are the solid contents of pigment, fixing resin, and wax, respectively.

[0188] Resin-dispersed pigments: To 15 parts by mass of carbon black, 10 parts by mass of ammonium salt of styrene-acrylic acid copolymer (weight average molecular weight 10,000) as a dispersant polymer component and 55 parts by mass of ion-exchanged water were added and thoroughly mixed, and then this mixture was dispersed in a sand mill (manufactured by Yaskawa Corporation) together with glass beads (diameter 1.7 mm, 1.5 times the amount of the solid content of the mixture) for 2 hours. After dispersion, the glass beads were removed to obtain a resin-dispersed pigment dispersion liquid, which was used.

[0189] JONCRYL 631: BASF styrene-acrylic resin emulsion Superflex 210: urethane resin emulsion manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Hi-Tec E7100S: Toho Chemical Industry Co., Ltd., polyethylene wax Hi-Tec E6314: Polyethylene wax manufactured by Toho Chemical Industry Co., Ltd. AQUACER539: Paraffin wax manufactured by BYK Japan Co., Ltd. AQUACER515: Polyethylene wax manufactured by BYK Japan Co., Ltd. BYK-348: BYK Japan Co., Ltd., silicone surfactant BYK-333: BYK Japan Co., Ltd., silicone surfactant DF110D: Acetylene glycol surfactant manufactured by Air Products Japan Co., Ltd. The particle size of the wax was measured by diluting the product used by 400 times and using a nanoparticle size measuring device NANOTRACKWAVE II manufactured by Microtrac, and the results are shown in the table.

[0190] 3.2.Evaluation Method 3.2.1. Recording test A modified SC-S80650 (manufactured by Seiko Epson) was prepared. The nozzle density of the nozzle row of the head was 360 dpi. A platen heater and a blowing fan were provided, and the fan air speed was set to 5 m / s. The air temperature was set to 25°C. The primary heating temperature (surface temperature of the recording medium) during composition deposition was set to the temperatures shown in Tables 3 to 5. Secondary heating was performed using a downstream secondary heater at a surface temperature of the recording medium of 70°C.

[0191] The ejection order of the color ink and the clear ink was as follows: simultaneous: simultaneous deposition in the second deposition mode described above, and colored ink: sequential deposition in the first deposition mode described above. The application range of the clear ink to the non-image area was as follows: full area: applied to the entire non-image area of ​​the recordable area of ​​the recording medium; partial area: applied to the entire image area up to 5 cm from the edge of the image area. The recording medium was 30 x 60 cm, and a solid pattern image area of ​​5 x 10 cm was printed in the center of the recording medium in the long side direction of the recording medium.

[0192] The amount of clear ink applied to the non-image area was set to the value in the table. In the example where clear ink was applied to the image area, clear ink was applied to the entire image area, and the amount of application was set to the value in the table. The recording resolution during printing is 1440 x 720 dpi, and the amount of color ink applied to the image area is 7 mg / inch. 2 Unless otherwise specified, the number of passes was 8. The clear ink was applied using the same printing method as the color ink. The amount of ink applied was adjusted by the dot density.

[0193] 3.2.2. Evaluation substrate The evaluation substrates (printing substrates) used in each example are shown in Tables 3 to 5 below. Y-1: Lintec YUPO (UV) PAT1 9K, substrate surface roughness (Sa) = 0.7 μm Y-2: Super Yupo FRRG manufactured by Yupo Corporation. In-plane surface roughness (Sa) of the base material = 0.4 μm Y-3: New Yupo FGS#130 manufactured by Yupo Corporation. In-plane surface roughness (Sa) of the substrate = 1.0 μm P: Lintec PET50A substrate in-plane surface roughness (Sa) = 0.07 μm The surface roughness was measured using a laser microscope VK-X1000 with an objective lens of 20x magnification to measure the in-plane surface roughness (Sa).

[0194] 3.2.3. Evaluation of drying properties Printing was performed under 8-pass or 6-pass printing conditions. The number of passes was the same for both color inks and clear inks. After printing, the printed material was cut out and rubbed 10 times with a Bemcot across the image and non-image areas, and the image area and Bemcot staining were observed. The rub was performed along the long direction of the image area. Evaluation was based on the following criteria, and the results are shown in the table. A: No color transfer to Bemcot or staining of the image area was observed in 6 passes. B: No color transfer to Bemcot or staining of image area observed in 8 passes. C: In the 8-pass test, color transfer to the Bemcot or staining of the image area was observed. Furthermore, since Bemcot is not synthetic paper (such as YUPO), it is thought that there is no abrasion caused by the fine particles contained in synthetic paper. If the clear ink in the non-image areas does not dry sufficiently, the clear ink may transfer from the non-image areas to the image areas, preventing the image areas from drying.

[0195] 3.2.4. Evaluation of abrasion resistance For each example, the abrasion resistance (staining of non-image areas) was evaluated. The obtained recorded matter was rubbed with friction paper in the long side direction of the image area of ​​the recorded matter 30 times at 500 g using a Gakushin-type abrasion fastness tester (manufactured by Tester Sangyo Co., Ltd.). The friction paper had the same substrate as that used for recording. In the examples where clear ink was used, the clear ink of each example was applied to the substrate and rubbed all over the surface of the friction paper at 1 mg / cm². inch 2 The clear ink was applied to the non-image area, and this was used as friction paper. In the examples where the clear ink was not applied to the non-image area (Comparative Examples 4 and 5 and Reference Example), evaluation was performed using friction paper without the clear ink applied. In addition, when rubbing, the friction element was made to reciprocate across the image area. In other words, the image area was rubbed from one end of the recording area of ​​the recorded material to the other end. The rub was made in the long side direction. The evaluation was based on the following criteria, and the results are shown in the table. A: No background staining is observed in the non-image area. B: A slight amount of background smearing in non-image areas is observed, but is not noticeable. C: There is background smearing in the non-image area, but it is not observed within an area of ​​1 cm or more from the edge of the image area. D: Background staining in non-image areas is noticeable, and is observed in an area of ​​1 cm or more from the edge of the image area.

[0196] 3.2.5. Evaluation of Scratch Resistance (Ink Transfer) The same recording material as in the evaluation of abrasion resistance was recorded and the same test was carried out. Evaluation was made according to the following criteria, and the results are shown in the table. A: Almost no color transfer to the friction paper is observed. B: A slight color transfer to the friction paper is observed, but it is not noticeable. C: Slight color transfer to the friction paper is observed. D: Color transfer to the friction paper is clearly observed.

[0197] 3.2.6. Evaluation of bleeding The pattern shape differed from the evaluations above; a 1 cm wide grid pattern of color ink was printed. The areas other than the grid pattern of color ink were designated as non-image areas, and clear ink was applied. Bleeding of the color ink and clear ink at the boundary between the image and non-image areas was visually confirmed. Note that in this evaluation, since the color ink image area was a 1 cm wide grid pattern, the clear ink application range of the non-image area was equivalent to applying clear ink to the entire surface in some examples (Example 16). Evaluation was based on the following criteria, and the results are shown in the table. A: No bleeding is observed. B: When viewed up close, the blur is visible. C: There is some bleeding, but it is not noticeable. D: Visible bleeding.

[0198] 3.2.7. Evaluation of clogging recovery Recording was carried out for two hours under the above recording test conditions. However, after recording, a simulated recording was carried out in which no ink was ejected from the head. After recording, suction cleaning was carried out to restore non-ejecting nozzles, and then a nozzle inspection was carried out. Each cleaning involved ejecting 1 cc of ink from the nozzle row. Evaluation was based on the following criteria, and the results are shown in the table. This is an evaluation of clear ink. A: All nozzles are restored with one cleaning. B: All nozzles recovered after three cleanings. C: All nozzles recovered after six cleanings. D: There are nozzles that do not recover even after six cleanings.

[0199] 3.3.Evaluation Results The evaluation results are shown in Tables 3 to 5. The tables show that in the recording methods of each example, where the recording medium is a non-absorbent recording medium or a low-absorbent recording medium with a substrate having an in-plane surface roughness (Sa) of 0.2 μm or more, the clear ink composition contains a resin and a wax, and does not contain an organic solvent that is a polyol having a normal boiling point of 280° C. or higher in an amount of 0.5 mass % or more relative to the total mass of the clear ink composition, and the clear ink composition is applied to non-image areas, which are areas of the recording medium other than the image areas where the colored ink composition is applied, the resulting recorded matter has good abrasion resistance (staining of non-image areas).

[0200] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0201] The following can be derived from the above-described embodiment and modifications.

[0202] The recording method is an ink deposition step of ejecting an aqueous colored ink composition containing a colorant from an inkjet head and depositing the ink onto a recording medium; a clear ink deposition step of ejecting an aqueous clear ink composition from an inkjet head and depositing the ink onto a recording medium; and The recording medium is a non-absorbent or low-absorbent recording medium having an in-plane surface roughness (Sa) of the recording medium surface of 0.2 μm or more, the clear ink composition contains a resin and a wax, and does not contain an organic solvent that is a polyol having a normal boiling point of 280°C or higher in an amount of 0.5% by mass or more relative to the total mass of the clear ink composition; The clear ink composition is applied to non-image areas, which are areas other than image areas, which are areas of the recording medium where the colored ink composition is applied.

[0203] According to this recording method, even if the substrate is a non-absorbent or low-absorbent recording medium having an in-plane surface roughness (Sa) of 0.2 μm or more, it is possible to obtain a recorded matter that can suppress color transfer of the colored ink composition to non-image areas.

[0204] This effect is thought to be due to the resin contained in the clear ink composition flattening the non-image areas and the wax making them slippery, making it difficult for the components of the colored ink composition to transfer even when the non-image areas are rubbed.

[0205] Furthermore, according to this recording method, the clear ink composition does not contain organic solvents that are polyols with a normal boiling point of 280°C or higher in an amount of 0.5% by mass or more relative to the total mass of the clear ink composition, so that the ink dries well after being applied to the recording medium, and the above-mentioned effects can be obtained more quickly.

[0206] In the above recording method, The total content of the resin and the wax contained in the clear ink composition may be 4% by mass or more and 10% by mass or less with respect to the total mass of the clear ink composition.

[0207] According to this recording method, it is possible to further suppress the color transfer of the color ink composition to the non-image areas.

[0208] In the above recording method, The mass ratio of the resin to the wax contained in the clear ink composition (wax / resin) may be 0.25 or more.

[0209] According to this recording method, it is possible to further suppress the color transfer of the color ink composition to the non-image areas.

[0210] In the above recording method, The wax may be a polyolefin wax having a melting point of 120° C. or higher.

[0211] According to this recording method, it is possible to further suppress the color transfer of the color ink composition to the non-image areas.

[0212] In the above recording method, The wax may have a volume average particle size (D50) of 50 nm or more.

[0213] According to this recording method, it is easier to flatten the irregularities on the surface of the recording medium, and it is possible to further suppress color transfer of the color ink composition to non-image areas.

[0214] In the above recording method, The difference in surface tension between the colored ink composition and the clear ink composition may be 2 mN / m or less.

[0215] According to this recording method, it is possible to further suppress the color transfer of the color ink composition to the non-image areas.

[0216] In the above recording method, The total amount of the resin and the wax contained in the clear ink composition attached to the non-image area is 0.4 mg / inch 2 It may be the following:

[0217] According to this recording method, it is possible to further suppress the color transfer of the color ink composition to the non-image areas.

[0218] In the above recording method, The area of ​​the non-image area to which the clear ink composition is applied may include a range extending 2 cm or more from the edge of the periphery of the image area.

[0219] According to this recording method, even if the area in the non-image area to which the clear ink composition is applied is not the entire non-image area, color transfer of the colored ink composition to the non-image area can be suppressed.

[0220] In the above recording method, The amount of the clear ink composition adhered to the image area adjacent to the non-image area to which the clear ink composition has been adhered may be equal to or less than the amount of the clear ink composition adhered to the non-image area.

[0221] This recording method can further suppress color transfer of the colored ink composition to non-image areas. Furthermore, in this recording method, it is believed that applying a clear ink composition to the image area is effective but not essential. This can be inferred from the fact that the surface of the recording medium is rough, and although the colored ink composition is transferred by rubbing the image area, ink peeling in the image area is not noticeable even after transfer, while staining in the non-image area is noticeable. On the other hand, if a clear ink composition is applied to the image area, the total amount of adhesion in the image area may increase depending on the amount of adhesion, which may result in bleeding in the image area.

[0222] The recording device A recording device that performs any one of the above recording methods, the colored ink composition, the clear ink composition, and the colored ink composition and the and an inkjet head that ejects the clear ink composition.

[0223] This recording device can produce a recorded material that can suppress color transfer of the color ink composition to non-image areas, even on a non-absorbent or low-absorbent recording medium whose substrate has an in-plane surface roughness (Sa) of 0.2 μm or more. [Explanation of symbols]

[0224] 1...inkjet recording device, 2...inkjet head (2a...inkjet head that ejects colored ink composition, 2b...inkjet head that ejects clear ink composition), 3...IR heater, 4...platen heater, 5...heating heater, 6...cooling fan, 7...preheater, 8...ventilation fan, 9...carriage, 11...platen, 12...cartridge, 13...carriage moving mechanism, 14...conveying means, CONT...control unit, MS...main scanning direction, SS...sub-scanning direction, M...recording medium

Claims

1. an ink deposition step of ejecting an aqueous colored ink composition containing a colorant from an inkjet head and depositing the ink onto a recording medium; a clear ink deposition step of ejecting an aqueous clear ink composition from an inkjet head and depositing the ink onto a recording medium; and The recording medium is a non-absorbent or low-absorbent recording medium having an in-plane surface roughness (Sa) of the recording medium surface of 0.2 μm or more, the clear ink composition contains a resin and a wax, and does not contain an organic solvent that is a polyol having a normal boiling point of 280°C or higher in an amount of 0.5% by mass or more relative to the total mass of the clear ink composition; A recording method comprising depositing the clear ink composition to a non-image area, which is an area other than an image area, which is an area to which the colored ink composition is deposited, of a recording medium.

2. In claim 1, a total content of the resin and the wax contained in the clear ink composition being 4% by mass or more and 10% by mass or less with respect to the total mass of the clear ink composition;

3. In claim 1, A recording method, wherein the mass ratio of the resin to the wax (wax / resin) contained in the clear ink composition is 0.25 or more.

4. In claim 1, The recording method, wherein the wax is a polyolefin wax having a melting point of 120° C. or higher.

5. In claim 1, A recording method, wherein the wax has a volume average particle diameter (D50) of 50 nm or more.

6. In claim 1, a difference in surface tension between the colored ink composition and the clear ink composition being 2 mN / m or less;

7. In claim 1, The total amount of the resin and the wax contained in the clear ink composition in the non-image area is 0.4 mg / inch ２ The recording method is as follows.

8. In claim 1, A recording method, wherein the area of ​​the non-image area to which the clear ink composition is applied includes an area extending 2 cm or more from the edge of the periphery of the image area.

9. In claim 1, A recording method, wherein the amount of the clear ink composition adhered to the image area adjacent to the non-image area to which the clear ink composition has been adhered is equal to or less than the amount of the clear ink composition adhered to the non-image area.

10. A recording apparatus for performing the recording method according to any one of claims 1 to 9, A recording apparatus comprising: the colored ink composition; the clear ink composition; and an inkjet head that ejects the colored ink composition and the clear ink composition.

Images