Recording method and recording device

Abstract

To provide a recording method which is excellent in scratch resistance and image quality of a recorded matter.SOLUTION: A recording method for performing recording on a recording medium which has surface roughness Sa of 1 μm or more and has a low absorptive or non-absorptive property, includes: a treatment liquid adhesion step of causing a treatment liquid containing a coagulant to adhere onto the recording medium; an ink adhesion step of discharging a coloring ink composition from the inkjet head to cause the coloring ink composition to adhere onto the recording medium; and a clear ink adhesion step of discharging a clear ink composition from the inkjet head to cause the clear ink composition to adhere onto the recording medium. Therein: the coloring ink composition is an aqueous ink composition containing a coloring material, first resin particles, and second resin particles; the clear ink composition is an aqueous ink composition containing first resin particles, and second resin particles; the first resin particles are made of any one of an acrylic resin, an urethane-based resin and a polyester-based resin; the second resin particles are made of a polyolefin-based resin; the coloring ink composition has a content of the first resin particles being 3 mass% or more with respect to the total mass of the ink composition; and the clear ink composition has the content of the first resin particles being 3 mass% or more with respect to the total mass of the ink composition.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] The inkjet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. In particular, printing on recording media that are low-absorbent or non-absorbent and have unevenness on the printing surface (hereinafter also referred to as "low-absorbent uneven media"), such as PVC wallpaper, is being studied.

[0003] For example, Patent Document 1 describes a method of applying ink to vinyl chloride wallpaper using an inkjet printer to perform recording. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-67068 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the abrasion resistance and image quality of the recorded material are still not satisfactory. [Means for solving the problem]

[0006] One aspect of the recording method according to the present invention is to A recording method for recording on a recording medium having a surface roughness Sa of 1 μm or more and low absorbency or non-absorbency, comprising the steps of: a treatment liquid applying step of applying a treatment liquid containing a flocculant to the recording medium; an ink depositing step of ejecting a colored ink composition from an inkjet head and depositing the colored ink composition on the recording medium; a clear ink applying step of ejecting a clear ink composition from an inkjet head and applying the clear ink composition to the recording medium, the colored ink composition is a water-based ink composition containing a color material, first resin particles, and second resin particles; the clear ink composition is a water-based ink composition containing first resin particles and second resin particles, the first resin particles are made of any one of an acrylic resin, a urethane resin, and a polyester resin; the second resin particles are made of a polyolefin resin, the content of the first resin particles in the colored ink composition is 3% by mass or more based on the total mass of the ink composition; The clear ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition.

[0007] One aspect of the recording device according to the present invention is A recording apparatus for recording on the recording medium according to the recording method of the above aspect, The ink jet head includes the treatment liquid, the colored ink composition, the clear ink composition, a treatment liquid application mechanism that applies the treatment liquid, an inkjet head that ejects the colored ink composition, and an inkjet head that ejects the clear ink composition. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating an ink jet recording apparatus. [Diagram 2] FIG. 2 is a perspective view showing an example of a configuration around a carriage of an inkjet recording apparatus. [Diagram 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. [Diagram 5] Table 1 shows an example of the composition of the treatment liquid. [Figure 6] FIG. 2 shows examples of compositions of colored ink compositions (Table 2). [Figure 7] FIG. 3 shows examples of clear ink compositions (Table 3). [Figure 8] A diagram showing an example of the recording method and the evaluation results (Table 4). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described. The embodiment described below is an example of the present invention. The present invention is not limited to the following embodiment, and includes various modified forms that are implemented within the scope that does not change the gist of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0010] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0011] 1. Recording method A recording method according to one embodiment of the present invention is a recording method for recording on a recording medium having a surface roughness Sa of 1 μm or more and which is low-absorbent or non-absorbent, the recording method comprising: a treatment liquid applying step of applying a treatment liquid containing a coagulant to the recording medium; an ink applying step of ejecting a colored ink composition from an inkjet head to apply it to the recording medium; and a clear ink applying step of ejecting a clear ink composition from an inkjet head to apply it to the recording medium, wherein the colored ink composition is an aqueous ink composition containing a colorant, first resin particles, and second resin particles; the clear ink composition is an aqueous ink composition containing the first resin particles and the second resin particles, the first resin particles being made of any one of an acrylic resin, a urethane resin, and a polyester resin, and the second resin particles being made of a polyolefin resin; the colored ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition; and the clear ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition.

[0012] In inkjet printing on low-absorption uneven media, the use of a treatment liquid containing a flocculant to reduce and fix the ink's fluidity soon after deposition is being considered to achieve excellent image quality.

[0013] However, in low non-absorbent stepped media, the solid content of the ink aggregated by the treatment liquid tends to gather in the recesses of the recording medium surface. Meanwhile, the ink layer on the protrusions of the recording medium surface tends to become thin. Furthermore, when the low non-absorbent stepped media is rubbed, the protrusions tend to get caught. Thus, low non-absorbent stepped media has poor abrasion resistance due to the thin ink layer and the presence of protrusions that tend to get caught.

[0014] In contrast, according to the recording method of this embodiment, a clear ink composition is further used, and first resin particles (made of any of an acrylic resin, a urethane resin, or a polyester resin) and second resin particles (made of a polyolefin resin) are contained in both the clear ink composition and the colored ink composition, and the content of the first resin particles is 3 mass% or more in both inks, making it possible to obtain excellent abrasion resistance and image quality.

[0015] Hereinafter, each step of the recording method according to this embodiment and the recording medium used therein will be described.

[0016] 1.1 Recording medium The recording method according to this embodiment is for recording on a recording medium that has a surface roughness Sa of 1 μm or more and is low absorbent or non-absorbent.

[0017] A low-absorbency or non-absorbency recording medium refers to a recording medium that does not absorb liquid at all or absorbs very little liquid. 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 2The Bristow method is the most widely used method for measuring the amount of liquid absorbed in a short period of time, and is also used 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 Testing Methods 2000 Edition." In contrast, absorbent recording media refers to recording media that do not fall under the category of low absorbency or non-absorbency recording media.

[0018] 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 art paper, coated paper, matte paper, or other printing paper, and the substrate may be a plastic film, such as polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, or other plastic film coated with a polymer or other particles together with a binder.

[0019] 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, plastic films that do not have an absorption layer (receptive layer), etc. Examples of such plastics include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc.

[0020] In this specification, "surface roughness Sa" refers to the "arithmetic mean height Sa" defined in ISO 25178. The arithmetic mean height Sa represents the average of the absolute values ​​of the height differences (z(x, y)) from the average plane of each measurement point in the reference area A, and is expressed by the following formula. Sa = (1 / A) ∬ A |z(x,y)|dxdy

[0021] The surface roughness Sa can be measured, for example, by using a laser microscope (VK-X1000 / manufactured by Keyence) according to a method conforming to ISO25178.

[0022] The surface roughness Sa of the recording medium used in the recording method according to this embodiment is 1 μm or more, preferably 1.5 μm or more, more preferably 2.0 μm or more, even more preferably 2.5 μm or more, and particularly preferably 3.0 μm or more. According to the recording method according to this embodiment, even if the recording medium has a large surface roughness Sa, it tends to be possible to obtain excellent abrasion resistance and image quality. The upper limit of the surface roughness Sa is not particularly limited, but is preferably 30 μm or less, more preferably 15 μm or less, even more preferably 10 μm or less, and particularly preferably 5 μm or less.

[0023] The recording medium used in the recording method according to the present embodiment is preferably wallpaper. According to the recording method according to the present embodiment, there is a tendency that excellent abrasion resistance and image quality can be obtained even when printing on wallpaper.

[0024] Examples of wallpaper include PRSO401F (vinyl chloride, Sa=3.3 μm), PRSO40WF (vinyl chloride, Sa=8.9 μm), PRSO101S (vinyl chloride, Sa=10.8 μm), PRSO10WS (vinyl chloride, Sa=29.9 μm) (all product names manufactured by Lintec Sign Systems Co., Ltd.), and DV662 (product name manufactured by Neschen GmbH, non-vinyl chloride, Sa=1.7 μm).

[0025] 1.2 Treatment solution application process The recording method according to this embodiment includes a treatment liquid application step of applying a treatment liquid containing a flocculant to the above-mentioned recording medium.

[0026] 1.2.1 Attachment pattern The method for depositing the treatment liquid on the recording medium may be any of non-contact and contact methods, or a combination of these, such as an inkjet method, a coating method using a roller or bar, a method of coating the recording medium with the treatment liquid using various sprays, a method of immersing the recording medium in the treatment liquid and coating it, a method of coating the recording medium with the treatment liquid using a brush, etc. Of these, the inkjet method is preferred.

[0027] The amount of the treatment liquid applied is 0.1 to 10.0 mg / inch per unit area of ​​the recording medium. 2 is preferable, and 0.5 to 8.0 mg / inch 2 More preferably, 1.0 to 6.0 mg / inch 2 More preferably, 1.5 to 5.0 mg / inch 2 is particularly preferred, and 2.0 to 4.5 mg / inch 2 More particularly preferably, 2.5 to 4.0 mg / inch 2 is particularly preferred. When the amount of the treatment liquid applied is within the above range, better image quality and abrasion resistance tend to be obtained. It is also preferred that the maximum amount of the treatment liquid applied is within the above range.

[0028] The amount of the treatment liquid adhered is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, further preferably 15 to 35% by mass, and particularly preferably 20 to 30% by mass, based on the amount of the color ink composition adhered to the recording medium. When the amount of the treatment liquid adhered is within the above range, better image quality and abrasion resistance tend to be obtained.

[0029] In the recording method according to the present embodiment, the treatment liquid application step is preferably performed by scanning the inkjet head while moving the inkjet head, ejecting the treatment liquid from the inkjet head, and applying it to the recording medium. In this case, it is easy to control the amount of treatment liquid applied and the location where it is applied. Furthermore, the ink application step described below is preferably performed by performing scanning to apply the treatment liquid to the same scanning area as the scanning to apply the colored ink composition. In such an application mode (simultaneous ejection), the treatment liquid and the colored ink composition are more likely to mix and react with each other. This promotes thickening and aggregation of the ink, and allows the ink droplets to be fixed on the media earlier, which tends to result in better image quality and abrasion resistance.

[0030] The above-described adhesion mode can be achieved, for example, in a case where the nozzle surface of the inkjet head has a plurality of nozzle rows along the head movement direction, each nozzle row being made up of a plurality of nozzles that are arranged along a direction (hereinafter also referred to as the "nozzle row direction") that intersects with the direction in which the inkjet head is moved (hereinafter also referred to as the "head movement direction"), by arranging the nozzle row that ejects the treatment liquid so that, when projected along the head movement direction, it at least partially overlaps with the nozzle row that ejects the colored ink composition in the nozzle row direction, and it is preferable to arrange them so that they completely overlap.

[0031] 1.2.2 Processing solution The components contained in the treatment liquid used in the treatment liquid application step will be described below. The treatment liquid is not an ink composition used to color a recording medium, but an auxiliary liquid used together with the ink composition used to color the recording medium. The treatment liquid may contain a coloring material such as a pigment, but the amount of the coloring material is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less, with the lower limit being 0% by mass, relative to the total mass of the treatment liquid. It is preferable that the treatment liquid does not contain a coloring material.

[0032] [Flocculant] The treatment liquid used in the recording method according to this embodiment contains an aggregating agent that aggregates the components of the ink. The aggregating agent reacts with components such as the coloring material contained in the ink and the resin particles that may be contained in the ink, thereby aggregating the coloring material and the resin particles. However, the degree of aggregation of the coloring material and the resin particles by the aggregating agent varies depending on the type of the aggregating agent, the coloring material, and the resin particles, and can be adjusted. Such aggregation can, for example, enhance the color development of the coloring material, enhance the fixation of the resin particles, and / or increase the viscosity of the ink.

[0033] The flocculant is not particularly limited, but may be metal salt, organic acid, inorganic acid, cationic compound, etc., and the cationic compound may be cationic resin (cationic polymer), etc. Among these, the metal salt is preferably a polyvalent metal salt, and the cationic compound is preferably a cationic resin. Therefore, from the viewpoint of obtaining better image quality, abrasion resistance, gloss, etc., the flocculant is preferably selected from cationic resin, organic acid, and polyvalent metal salt, and polyvalent metal salt is particularly preferred.

[0034] (polyvalent metal salts) A polyvalent metal salt is a compound composed of a divalent or higher metal ion and an anion. Examples of divalent or higher metal ions include calcium, magnesium, copper, nickel, zinc, barium, aluminum, titanium, strontium, chromium, cobalt, and iron ions. Among the metal ions that compose these polyvalent metal salts, at least one of calcium ions and magnesium ions is preferred because they have excellent coagulation properties for the ink components.

[0035] The anions constituting the polyvalent metal salt are inorganic ions or organic ions. That is, the polyvalent metal salt in the present invention is composed of inorganic ions or organic ions and polyvalent metals. Examples of such inorganic ions include chloride ions, bromide ions, iodide ions, nitrate ions, sulfate ions, hydroxide ions, etc. Examples of organic ions include organic acid ions, such as carboxylate ions and formate ions.

[0036] The polyvalent metal compound is preferably an ionic polyvalent metal salt, and in particular, when the polyvalent metal salt is a magnesium salt or a calcium salt, the stability of the treatment solution is improved. The counter ion of the polyvalent metal may be either an inorganic acid ion or an organic acid ion.

[0037] Specific examples of the polyvalent metal salt include calcium carbonate, such as heavy calcium carbonate and light calcium carbonate, calcium nitrate, calcium chloride, calcium sulfate, magnesium sulfate, calcium hydroxide, magnesium chloride, magnesium carbonate, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, magnesium silicate, copper nitrate, calcium formate, calcium acetate, calcium propionate, calcium lactate, magnesium acetate, and aluminum acetate. These polyvalent metal salts may be used alone or in combination of two or more. Among these, at least one of calcium formate, calcium propionate, calcium lactate, magnesium sulfate, calcium nitrate, and calcium chloride is preferred because it can ensure sufficient solubility in water and reduces traces left by the treatment solution (the traces become less noticeable), and calcium formate and calcium nitrate are more preferred. Note that these metal salts may have hydration water in the raw material form.

[0038] Examples of metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts, for example, sodium sulfate and potassium sulfate.

[0039] (organic acid) Suitable examples of organic acids include poly(meth)acrylic acid, acetic acid, glycolic acid, malonic acid, malic acid, maleic acid, ascorbic acid, succinic acid, glutaric acid, fumaric acid, citric acid, tartaric acid, lactic acid, sulfonic acid, orthophosphoric acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, or derivatives of these compounds, or salts thereof. Organic acids may be used alone or in combination of two or more. Salts of organic acids that are metal salts are included in the above metal salts.

[0040] (Inorganic acid) Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, etc. The inorganic acids may be used alone or in combination of two or more kinds.

[0041] (cationic resin) Examples of the cationic resin (cationic polymer) include cationic urethane resin, cationic olefin resin, cationic amine resin, etc. The cationic polymer is preferably water-soluble.

[0042] As the cationic urethane-based resin, commercially available products can be used, such as HYDRAN CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, and CP-7610 (product names, manufactured by Dainippon Ink and Chemicals, Inc.), SUPERFLEX 600, 610, 620, 630, 640, and 650 (product names, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and urethane emulsions WBR-2120C and WBR-2122C (product names, manufactured by Taisei Fine Chemical Co., Ltd.).

[0043] The cationic olefin resin has an olefin such as ethylene or propylene in the structural skeleton, and known resins can be appropriately selected and used. The cationic olefin resin may be in an emulsion state dispersed in a solvent including water or an organic solvent. As the cationic olefin resin, a commercially available product can be used, and examples thereof include Arrowbase CB-1200 and CD-1200 (trade names, manufactured by Unitika Ltd.).

[0044] The cationic amine resin (cationic polymer) may be any resin having an amino group in its structure, and known resins may be appropriately selected and used. For example, polyamine resins, polyamide resins, polyallylamine resins, etc. may be mentioned. Polyamine resins are resins having amino groups in their main skeletons. Polyamide resins are resins having amide groups in their main skeletons. Polyallylamine resins are resins having a structure derived from allyl groups in their main skeletons.

[0045] Examples of cationic polyamine resins include Unisense KHE103L (hexamethylenediamine / epichlorohydrin resin, 1% aqueous solution with a pH of about 5.0, viscosity of 20 to 50 (mPa s), and a solids concentration of 50% by mass) and Unisense KHE104L (dimethylamine / epichlorohydrin resin, 1% aqueous solution with a pH of about 7.0, viscosity of 1 to 10 (mPa s), and a solids concentration of 20% by mass), both manufactured by Senka Corporation. Specific examples of commercially available cationic polyamine resins include FL-14 (manufactured by SNF Co., Ltd.), Arafix 100, 251S, 255, 255LOX (manufactured by Arakawa Chemical Co., Ltd.), DK-6810, 6853, 6885; WS-4010, 4011, 4020, 4024, 4027, 4030 (manufactured by Seiko PMC Co., Ltd.), Papiogene P-105 (manufactured by Senka Co., Ltd.), and Sumirez Resin 6. 50(30), 675A, 6615, SLX-1 (manufactured by Taoka Chemical Co., Ltd.), Catiomaster (registered trademark) PD-1, 7 (epichlorohydrin-amine derivative resin), 30, A, PDT-2, PE-10, PE-30, DT-EH, EPA-SK01, TMHMDA-E (manufactured by Yokkaichi Synthetic Co., Ltd.), Jetfix 36N, 38A, 5052 (manufactured by Satoda Chemical Co., Ltd.).

[0046] The polyamine resin may also be a polyallylamine resin. Examples of the polyallylamine resin include polyallylamine hydrochloride, polyallylamine amide sulfate, allylamine hydrochloride-diallylamine hydrochloride copolymer, allylamine acetate-diallylamine acetate copolymer, allylamine acetate-diallylamine acetate copolymer, allylamine hydrochloride-dimethylallylamine hydrochloride copolymer, allylamine-dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamine amide sulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate-sulfur dioxide copolymer, diallylmethylethylammonium ethyl sulfate-sulfur dioxide copolymer, methyldiallylamine hydrochloride-sulfur dioxide copolymer, diallyldimethylammonium chloride-sulfur dioxide copolymer, diallyldimethylammonium chloride-acrylamide copolymer, and the like.

[0047] A plurality of types of these flocculants may be used. Furthermore, by selecting at least one of the polyvalent metal salts, organic acids, and cationic resins from among these flocculants, the flocculation action is more excellent, and therefore an image of higher quality (particularly with better color development) can be formed.

[0048] The total content of the flocculant in the treatment liquid is, for example, preferably 1% by mass or more and 30% by mass or less, based on the total mass of the treatment liquid. The lower limit of the content is preferably 2% by mass or more, and more preferably 3% by mass or more. The upper limit of the content is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, and particularly preferably 5% by mass or less. In addition, even when the aggregating agent is used in both the solution and the dispersion, the solid content is preferably within the above range. If the aggregating agent content is 1% by mass or more, the aggregating agent tends to have a sufficient ability to aggregate the components contained in the ink. In addition, if the aggregating agent content is 20% by mass or less, the solubility and dispersibility of the aggregating agent in the treatment liquid becomes better, and the storage stability of the treatment liquid tends to be improved.

[0049] Even if the organic solvent that may be contained in the treatment liquid has high hydrophobicity, the solubility of the flocculant in the treatment liquid is good. Therefore, it is preferable to use a flocculant with a solubility of 1 g or more in 100 g of water at 25°C, and it is more preferable to use one with a solubility of 3 g or more and 80 g or less.

[0050] [Water-soluble low molecular weight organic compound] The treatment liquid used in the recording method according to the present embodiment may contain a water-soluble low molecular weight organic compound. The water-soluble low molecular weight organic compound may be an organic solvent that is liquid at room temperature or may be solid at room temperature. An organic solvent is preferred.

[0051] Here, for a water-soluble low molecular weight organic compound, "water-soluble" means that the solubility in 100 g of water at 20°C is more than 10 g. The method for determining the solubility of a water-soluble low molecular weight organic compound is as follows. First, in an environment of 20°C, a predetermined amount of the compound is mixed with 100 g of water and stirred for 30 minutes. After stirring, if there is no phase separation or sea-island structure, the compound that is liquid at room temperature is judged to be soluble. Furthermore, if there is no residual residue, the compound that is solid at room temperature is judged to be soluble. In this way, when a given amount of a compound is mixed with 100 g of water, the largest amount among the amounts that are determined to be dissolved is taken as the solubility. A low molecular weight organic compound with a solubility of more than 10 g is considered to be a water-soluble low molecular weight organic compound.

[0052] The water-soluble low molecular weight organic compound may be a compound that is completely miscible with water or a compound that is miscible with water. In this specification, "completely miscible with water" refers to a case where water and an organic compound are mutually soluble, i.e., the solubility of the organic compound in 100 g of water at 20° C. is infinite. Also, "miscible with water" refers to a case where water and an organic compound have finite solubility, i.e., the solubility of the organic compound in 100 g of water at 20° C. is at least more than 10 g. The solubility of the water-soluble low molecular weight organic compound is more than 10 g, but there is no upper limit and it may be infinite. The solubility is preferably 11 g or more, more preferably 50 g or more.

[0053] In addition, in the water-soluble low-molecular-weight organic compound, the term "low molecular weight" refers to a molecular weight of 500 or less. The molecular weight is preferably 400 or less, more preferably 300 or less, and further preferably 50 to 200.

[0054] The water-soluble low molecular weight organic compound preferably includes one having a normal boiling point of 150 to 350° C., more preferably 150 to 300° C. The water-soluble low molecular weight organic compound preferably includes a compound having a melting point of 90° C. or lower, and more preferably includes a compound having a melting point of 80° C. or lower. The melting point is preferably −70° C. or higher.

[0055] Examples of the water-soluble low molecular weight organic compound include resin-dissolving substances, polyols, glycol ethers, alkanolamines, etc. The resin-dissolving substances are preferably selected from amides, sulfur-containing solvents, and cyclic ethers. Among these, resin-dissolving substances, polyols, and glycol ethers are preferred. More preferred examples of the resin-dissolving substance include amides, sulfur-containing solvents, and cyclic ethers having a normal boiling point of 150 to 300° C., and polyols and glycol ethers having a normal boiling point of 150 to 250° C. If necessary, the solvent may contain other water-soluble low-molecular organic compounds.

[0056] The water-soluble low molecular weight organic compound is preferably contained in an amount of 50% by mass or less relative to the total mass of the treatment liquid, and more preferably 1% by mass or more relative to the total mass of the treatment liquid, more preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and particularly preferably 20 to 30% by mass.

[0057] <Resin dissolved substances> Examples of resin-dissolving substances include amides, sulfur-containing solvents, and cyclic ethers. Among them, amides, sulfur-containing solvents, and cyclic ethers having a normal boiling point of 150 to 300° C. are preferable. The resin-dissolving substance is an organic compound that has a function of dissolving resin and improving abrasion resistance, but is not limited to this function.

[0058] Examples of the amides include cyclic amides (lactams) such as 2-pyrrolidone (2P), 2-piperidone, ε-caprolactam (CPL), N-methyl-ε-caprolactam, N-cyclohexyl-2-pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, 5-methyl-2-pyrrolidone, β-propiolactam, and ω-heptalactam; N,N-dimethylacetoacetamide, N,N-diethylacetoacetamide, N- Methylacetoacetamide, N,N-dimethylisobutyric acid amide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionamide, 3-methoxy-N,N-dimethylpropanamide (DMPA), 3-n-butoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, 3-methoxy-N,N-methylethylpropamide propionamide, 3-ethoxy-N,N-dimethylpropionamide, 3-ethoxy-N,N-diethylpropionamide, 3-ethoxy-N,N-methylethylpropionamide, 3-n-butoxy-N,N-diethylpropionamide, 3-n-butoxy-N,N-methylethylpropionamide, 3-n-propoxy-N,N-dimethylpropionamide, 3-n-propoxy-N,N-diethylpropionamide, 3-n-propoxy-N,N-methylethylpropionamide, Examples of suitable amides include linear amides such as 3-iso-propoxy-N,N-dimethylpropionamide, 3-iso-propoxy-N,N-diethylpropionamide, 3-iso-propoxy-N,N-methylethylpropionamide, 3-tert-butoxy-N,N-dimethylpropionamide, 3-tert-butoxy-N,N-diethylpropionamide, and 3-tert-butoxy-N,N-methylethylpropionamide. Among these, 2-pyrrolidone (2P), ε-caprolactam (CPL), and 3-methoxy-N,N-dimethylpropanamide (DMPA) are more preferable, as they tend to provide the processing solution with better storage stability.

[0059] Examples of the sulfur-containing solvent include 3-methylsulfolane, sulfolane, ethyl isopropyl sulfone, ethyl methyl sulfone, dimethyl sulfone, dimethyl sulfoxide (DMSO), diethyl sulfoxide, tetramethylene sulfoxide, methyl phenyl sulfoxide, etc. Among these, dimethyl sulfoxide (DMSO) is more preferable, and tends to provide the treatment solution with better storage stability.

[0060] Examples of the cyclic ethers include isosorbide dimethyl ether, 3-methyl-3-oxetanemethanol, 3-ethyl-3-oxetanemethanol (DMHD), 2-hydroxymethyloxetane, tetrahydrofurfuryl alcohol, solketal, glycerol formal, 1,4-dioxane-2,3-diol, dihydrolevoglucosenone, etc. Among these, 3-ethyl-3-oxetanemethanol (DMHD) is more preferable, and tends to provide the treatment solution with better storage stability.

[0061] <Polyols, glycol ethers> Examples of water-soluble low molecular weight organic compounds other than the above resin-dissolving substances include polyols and glycol ethers. Among them, either polyols or glycol ethers having a normal boiling point of 150 to 250° C. are preferred.

[0062] (Polyols) The polyol is preferably a glycol or a compound in which the hydroxyl groups of a glycol are intermolecularly condensed together, in which case the compound has two hydroxyl groups. Alternatively, the polyols may be a compound in which the hydrogen atoms of glycol or a compound in which glycol is condensed between hydroxyl groups are replaced with hydroxyl groups, in this case a compound having three or more hydroxyl groups. The glycol unit in the glycol constituting the polyol or in the compound in which the hydroxyl groups of the glycol are intermolecularly condensed together preferably has 2 to 10 carbon atoms, more preferably 3 to 8. The polyol preferably has 2 to 15 carbon atoms, more preferably 3 to 10 carbon atoms in the molecule. The polyols preferably have a normal boiling point of 150 to 250°C.

[0063] Examples of the polyols having a standard boiling point of 150 to 250° C. include ethylene glycol (standard boiling point 198° C., miscible with water), diethylene glycol (standard boiling point 244° C., completely miscible with water), 1,2-propanediol (propylene glycol: PG) (standard boiling point 188° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), 1,2-butanediol (propylene glycol: PG) (standard boiling point 188° C., completely miscible with water), Diol (standard boiling point 193°C, miscible with water), 1,2-pentanediol (standard boiling point 210°C, miscible with water), 1,2-hexanediol (standard boiling point 224°C, completely miscible with water), 1,3-propanediol (standard boiling point 214°C, completely miscible with water), 1,4-butanediol (standard boiling point 228°C, completely miscible with water), 2,3-butanediol (standard boiling point 177°C, miscible with water), 1, 3-Butylene glycol (normal boiling point 207°C, completely miscible with water), 3-methyl-1,3-butanediol (normal boiling point 203°C, completely miscible with water), 2-methyl-1,3-propanediol (normal boiling point 214°C, completely miscible with water), 2,2-dimethyl-1,3-propanediol (normal boiling point 208°C, solubility 83 [g / 100g water]), 2-methylpentane-2,4-diol (standard boiling point 197°C, completely miscible with water), 2,5-dimethyl-2,5-hexanediol (standard boiling point 218°C, solubility 14 [g / 100g water]), 1,5-pentanediol (standard boiling point 242°C, miscible with water), 3-methyl-1,5-pentanediol (standard boiling point 250°C, completely miscible with water), 1,6-hexanediol (standard boiling point 250°C, miscible with water), etc. As the polyol, polyols having 10 or less carbon atoms are more preferable.

[0064] Among the polyols, alkanediols having a standard boiling point of 150 to 250° C. and a carbon number of 10 or less are more preferable, and alkanediols having a standard boiling point of 150 to 250° C. and a carbon number of 6 or less are even more preferable. Examples of the alkanediols include 1,2-alkanediols such as ethylene glycol, propylene glycol, 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,3-propanediol, and 1,3-butylene glycol.

[0065] (Glycol ethers) Glycol ethers are compounds in which one or more hydroxyl groups of glycol are etherified. The glycol ethers are preferably monoethers or diethers of alkylene glycols. The etherified ethers are preferably alkyl ethers. The alkylene of the alkylene glycol and the alkyl of the alkyl ether, which constitute the glycol ethers, each independently preferably have 1 to 5 carbon atoms, more preferably 2 to 4 carbon atoms. Glycol ethers having a normal boiling point of 150 to 250°C are preferred.

[0066] Examples of glycol ethers include ethylene glycol monomethyl ether (completely miscible with water), ethylene glycol monoethyl ether (miscible with water), ethylene glycol monoisopropyl ether (solubility 100 [g / 100g water]), ethylene glycol monopropyl ether (miscible with water), ethylene glycol monoisobutyl ether (solubility 75.5 [g / 100g water]), ethylene glycol mono-tert-butyl ether (miscible with water), ethylene glycol monobutyl ether (solubility 100 [g / 100g water]), diethylene glycol Lithylene glycol monomethyl ether (completely miscible with water), diethylene glycol monoethyl ether (completely miscible with water), diethylene glycol monoisopropyl ether (completely miscible with water), diethylene glycol monoisobutyl ether (completely miscible with water), diethylene glycol monobutyl ether (completely miscible with water), triethylene glycol monomethyl ether (completely miscible with water), triethylene glycol monoethyl ether (completely miscible with water), triethylene glycol monobutyl ether (miscible with water), tetraethylene glycol monomethyl ether (completely miscible with water) Miscible with water), propylene glycol monomethyl ether (miscible with water), propylene glycol monoethyl ether (completely miscible with water), propylene glycol monopropyl ether (miscible with water), dipropylene glycol monomethyl ether (completely miscible with water), dipropylene glycol monopropyl ether (solubility 19 [g / 100g water]), tripropylene glycol monomethyl ether (completely miscible with water), 1,3-propanediol monomethyl ether (3-methoxy-1-propanol) (completely miscible with water), 1,3-butylene glycol-3-monomer Alkylene glycol monoalkyl ethers such as ethyl ether (3-methoxy-1-butanol) (miscible with water), and ethylene glycol dimethyl ether (completely miscible with water), diethylene glycol dimethyl ether (completely miscible with water), diethylene glycol methyl ethyl ether (completely miscible with water), diethylene glycol diethyl ether (completely miscible with water), triethylene glycol dimethyl ether (completely miscible with water), tetraethylene glycol dimethyl ether (completely miscible with water), dipropylene glycol dimethyl ether (solubility 52.Examples of alkylene glycol dialkyl ethers (glymes) include alkylene glycol dimethyl ether (solubility 23.6 [g / 100 g water]) and tripropylene glycol dimethyl ether (solubility 23.6 [g / 100 g water]).

[0067] Furthermore, of the above glycol ethers, diethers are more preferred than monoethers in that they tend to dissolve or swell the resin in the ink and improve the abrasion resistance of the formed image, whereas monoethers are preferred in that they provide excellent wetting and spreading properties of the treatment liquid.

[0068] The treatment liquid used in the recording method according to the present embodiment contains, as a water-soluble low molecular weight organic compound, either polyols or glycol ethers, in an amount of preferably 40% by mass or less, more preferably 30% by mass or less, based on the total mass of the treatment liquid, and the lower limit is 0% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more, based on the total mass of the ink composition. Furthermore, the above content range preferably includes either polyols or glycol ethers having a standard boiling point of 150 to 250°C, more preferably includes alkanediols having a standard boiling point of 150 to 250°C and having 10 or less carbon atoms, and particularly preferably includes alkanediols having a standard boiling point of 150 to 250°C and having 6 or less carbon atoms.

[0069] <Other compounds> The treatment liquid used in the recording method according to this embodiment may contain other water-soluble low molecular weight organic compounds as necessary.

[0070] (Alkanolamines) The treatment liquid may contain alkanolamines as the water-soluble low molecular weight organic compound. Alkanolamines are compounds having a hydroxyl group and an amino group in an alkane skeleton. The number of hydroxyl groups in the molecule of alkanolamines is 1 or more, preferably 1 to 5, and more preferably 2 to 3. The number of carbon atoms in the molecule of alkanolamines is preferably 1 to 20, more preferably 2 to 10, and even more preferably 6 to 9. The number of carbon atoms per alkane skeleton is preferably 1 to 6, and more preferably 2 to 4. The number of amino groups in the molecule of alkanolamines is 1 or more, preferably 1 to 5, and more preferably 1 to 2.

[0071] The alkanolamines are not particularly limited, and examples thereof include ethanolamine (miscible with water), N-methylethanolamine (solubility 100 [g / 100 g water]), N,N-dimethylethanolamine (completely miscible with water), N-ethylethanolamine (miscible with water), N-butylethanolamine (miscible with water), N,N-diethylethanolamine (miscible with water), diethanolamine (solubility 100 [g / 100 g water]), N-methyldiethanolamine (solubility 100 [g / 100 g water]), N-ethyldiethanolamine (miscible with water), N-butyldiethanolamine (miscible with water), N-tert-butyldiethanolamine (completely miscible with water), triethanolamine (completely miscible with water), isopropanolamine (miscible with water), N,N-dimethylisopropanolamine, amine (completely miscible with water), N,N-diethylisopropanolamine (miscible with water), diisopropanolamine (solubility 87 [g / 100g water]), triisopropanolamine (solubility 83 [g / 100g water]), N,N-dimethylpropanolamine (miscible with water), 2-amino-1-propanol (completely miscible with water), 2-amino-2-methyl-1-propanol (completely miscible with water), 5-amino-1-pentanol (miscible with water), 2-amino-2-methyl-1,3-propanediol (miscible with water), 2-amino-2-hydroxymethyl-1,3-propanediol (miscible with water), 3-amino-1,2-propanediol (miscible with water), 3-methylamino-1,2-propanediol (completely miscible with water), tripropanolamine, and tributanolamine. Among these, triethanolamine and triisopropanolamine are preferred, and triisopropanolamine is more preferred. The alkanolamines may be used alone or in combination of two or more.

[0072] When alkanolamines are contained, the content is preferably 1 mass % or less, and more preferably 0.05 to 0.5 mass %, based on the total mass of the treatment liquid.

[0073] (Polyols with normal boiling points above 280°C) The treatment liquid preferably does not contain polyols having a normal boiling point of more than 280° C. as a water-soluble low molecular weight organic compound in an amount of more than 3 mass % based on the total mass of the treatment liquid, more preferably does not contain more than 1 mass %, and even more preferably does not contain more than 0.5 mass %. In this case, the treatment liquid may or may not contain polyols having a standard boiling point of more than 280°C, and even if it does contain them, the content is not more than the above. If the content of polyols having a standard boiling point of more than 280°C is within the above range, the drying property of the treatment liquid can be prevented from being significantly reduced, and as a result, even if recording is performed on a recording medium that is low absorbent or non-absorbent, the fixing property of the image tends to be prevented from being reduced. In addition, there is a tendency that sufficient drying can be performed even if the temperature of the recording medium during heating and drying is relatively low. Examples of such polyols having a standard boiling point of more than 280°C include glycerin (standard boiling point 290°C), and do not include alkanolamines such as triisopropanolamine.

[0074] 〔water〕 The treatment liquid used in the recording method according to the present embodiment may contain water, and is preferably a water-based treatment liquid. Examples of water include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, and ultrapure water, which has reduced ionic impurities. In addition, if water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, the growth of bacteria and fungi can be suppressed when the treatment liquid is stored for a long period of time.

[0075] The content of water in the liquid medium component is preferably 30% by mass or more, and more preferably 30 to 99% by mass. It is further preferably 30 to 95% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass. The liquid medium is a solvent component such as water or an organic solvent. The water content is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, and particularly preferably 50% by mass or more, based on the total mass of the treatment liquid. The upper limit of the water content is not particularly limited, but is, for example, preferably 99% by mass or less, further 90% by mass or less, and more preferably 80% by mass or less, based on the total mass of the treatment liquid.

[0076] [Surfactant] The treatment liquid used in the recording method according to the present embodiment may contain a surfactant. The surfactant adjusts the surface tension of the treatment liquid and, for example, adjusts the wettability with the recording medium. Among the surfactants, for example, acetylene glycol surfactants, silicone surfactants, and fluorine surfactants can be preferably used, and silicone surfactants are more preferable.

[0077] The acetylene glycol surfactant is not particularly limited, but examples thereof include Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, and DF110D (all trade names, manufactured by Air Products & Chemicals, Inc.). , Olfin B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP.4001, EXP.4036, EXP.4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), Acetylenol E00, E00P, E40, E100 (all trade names, manufactured by Kawaken Fine Chemicals Co., Ltd.).

[0078] The silicone surfactant is not particularly limited, but a polysiloxane compound is preferred. The polysiloxane compound is not particularly limited, but for example, a polyether-modified organosiloxane is preferred. Commercially available products of the polyether-modified organosiloxane include, for example, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (all trade names, manufactured by BYK Japan), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF- 615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), Silface SAG002, 005, 503A, 008 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), and the like.

[0079] As the fluorosurfactant, it is preferable to use a fluorine-modified polymer, and specific examples include BYK-3440 (manufactured by BYK Japan), Surflon S-241, S-242, S-243 (all trade names, manufactured by AGC Seimi Chemical Co., Ltd.), and Futergent 215M (manufactured by NEOS Corporation).

[0080] When the treatment liquid contains a surfactant, multiple types of surfactants may be contained. When the treatment liquid contains a surfactant, the content of the surfactant may be 0.1% by mass or more and 2% by mass or less, preferably 0.2% by mass or more and 1.5% by mass or less, and more preferably 0.3% by mass or more and 1.0% by mass or less, based on the total mass of the treatment liquid.

[0081] [Other ingredients] The treatment liquid used in the recording method according to this embodiment may contain, in addition to the above-mentioned components, additives, resin dispersants, preservatives, antifungal agents, rust inhibitors, chelating agents, viscosity adjusters, antioxidants, and other components, as long as their functions are not impaired.

[0082] Examples of the additives include ureas, amines, and sugars. Examples of ureas include urea, ethyleneurea, tetramethylurea, 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). Examples of the amines include diethanolamine, triethanolamine, triisopropanolamine, etc. The ureas and amines may function as a pH adjuster. Examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0083] 1.3 Ink application process The recording method according to this embodiment includes an ink deposition step of ejecting a colored ink composition from an inkjet head and depositing the colored ink composition on a recording medium.

[0084] 1.3.1 Attachment pattern The amount of the color ink composition applied is 0.5 to 50.0 mg / inch per unit area of ​​the recording medium. 2 is preferable, and 1.0 to 40.0 mg / inch 2 More preferably, 3.0 to 30.0 mg / inch 2 More preferably, 5.0 to 25.0 mg / inch 2 is particularly preferred, and 7.0 to 25.0 mg / inch 2 More particularly preferably, 10.0 to 20.0 mg / inch 2 is particularly preferred. When the range of the adhesion amount of the color ink composition is within the above range, better image quality and abrasion resistance tend to be obtained. It is also preferred that the maximum adhesion amount of the color ink composition is within the above adhesion amount range.

[0085] As described above, the ink deposition step preferably involves performing a scan to deposit the treatment liquid in the same scanning region as the scan to deposit the colored ink composition.

[0086] 1.3.2 Pigmented ink composition The components contained in the colored ink composition used in the ink application step will be described below. The colored ink composition is a water-based ink composition that contains a color material, first resin particles, and second resin particles.

[0087] [Coloring material] The color ink composition used in the recording method according to this embodiment contains a color material. Examples of the color material include pigments and dyes.

[0088] (Pigments) As the pigment, for example, inorganic pigments including carbon black and titanium white, organic pigments, etc. can be used.

[0089] As the inorganic pigment, carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, iron oxide, titanium oxide, zinc oxide, silica, and the like can be used.

[0090] 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 of such tires include Cabot Corporation's Regal 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, and Elftex 12.

[0091] 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.

[0092] Specific examples of the organic pigment used in the colored ink composition include the following.

[0093] Examples of cyan pigments include CI Pigment Blue 1, 2, 3, 15:3, 15:4, 15:34, 16, 22, 60, etc.; CI Bat Blue 4, 60, etc., 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.

[0094] 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 include 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. A solid solution of the above pigments may also be used.

[0095] 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.

[0096] 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.

[0097] Luster pigments may also be used, and are not particularly limited as long as they can exhibit lustre when attached to a medium, but examples thereof 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 having pearly luster. Representative examples of pearl pigments include pigments having pearly luster or interference luster, such as titanium dioxide-coated mica, fish scale foil, and bismuth oxychloride. Luster pigments may also be surface-treated to suppress reaction with water.

[0098] White pigments may also be used, and examples of such pigments include metal oxides, barium sulfate, calcium carbonate, and other metal compounds. Examples of metal oxides include titanium dioxide, zinc oxide, silica, alumina, magnesium oxide, and other. As the white pigment, particles having a hollow structure may also be used.

[0099] 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.

[0100] The volume average particle diameter (D50) of the pigment, as measured by a dynamic light scattering method, 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.

[0101] The volume average particle diameter may be measured, for example, by a Nanotrack Series particle distribution measuring device manufactured by Microtrackbell Co., Ltd. Examples of a method for adjusting the volume average particle diameter include a method for adjusting the degree of pulverization of the pigment before dispersion, a method for adjusting the stirring conditions during dispersion (e.g., stirring speed, stirring temperature, etc.), and a method for adjusting by filtration using a filter after dispersion.

[0102] 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.

[0103] The pigment dispersant has the function of dispersing the pigment in the colored ink composition. The pigment dispersant may be water-soluble, but is preferably not completely water-soluble, and is considered to disperse the pigment by partially or entirely bonding 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. The pigment dispersed by the pigment dispersant which is a resin is also called a resin-dispersed pigment.

[0104] Examples of the resin of the pigment dispersant 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, vinyl naphthalene-(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, a polymer having a skeleton derived from (meth)acrylic acid and not having a skeleton derived from maleic acid or a compound similar thereto is referred to as an acrylic resin. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0105] Examples of the resin for the pigment dispersant include maleic acid-based resins and salts thereof, such as styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-maleic acid copolymer, and vinyl acetate-maleic acid ester copolymer; 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.

[0106] In addition to the above-mentioned polymers of acrylic monomers, the acrylic resin may be a copolymer of an acrylic monomer and another monomer. For example, an acrylic vinyl resin, which is a copolymer of a vinyl monomer as another monomer, is also called an acrylic resin. For example, among the above-mentioned styrene resins, a copolymer of a styrene monomer and an acrylic monomer is also included in the acrylic resin. Furthermore, when the acrylic resin is called an acrylic resin, its salts and esters are also included.

[0107] Examples of commercially available pigment dispersants include 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 Daiichi Kogyo Seiyaku Co., Ltd.).

[0108] 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.).

[0109] Commercially available urethane pigment dispersants include BYK-182, BYK-183, BYK-184, BYK-185 (manufactured by BYK-Chemie Co., Ltd.), TEGO Disperse710 (manufactured by Evonic Tego Chemi), and Borchi (registered trademark) Gen1350 (manufactured by OMG Borschers).

[0110] 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, more preferably 10% by mass or more and 20% by mass or less, based on 100% by mass of the ink. By making the content of the pigment dispersant 0.1% by mass or more, it is possible to ensure the dispersion stability of the pigment. In addition, if the content of the pigment dispersant is 30% by mass or less, it is possible to suppress the viscosity of the colored ink composition to a low level.

[0111] 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.

[0112] When the pigment is dispersed by a pigment dispersant, the ratio of the pigment to the pigment dispersant is preferably from 10:1 to 1:10, and more preferably from 4:1 to 1:3.

[0113] 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.

[0114] 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.

[0115] Of these, the self-dispersing pigment is preferably carbon black, from the viewpoints of being able to print black at a high density and being more excellent in ejection reliability.

[0116] 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., and "CAB-O-JET 200" and "CAB-O-JET 300" manufactured by Cabot Corporation.

[0117] (dye) The color 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.

[0118] The yellow dye is not particularly limited, but examples thereof include CI Acid Yellow 1, 3, 11, 17, 19, 23, 25, 29, 36, 38, 40, 42, 44, 49, 59, 61, 70, 72, 75, 76, 78, 79, 98, 99, 110, 111, 127, 131, 135, 142, 162, 164, and 165, and CI Direct Yellow 1, 8, 11, 12, 24, 26, 27, and 33. , 39, 44, 50, 58, 85, 86, 87, 88, 89, 98, 110, 132, 142, 144, 162, 165, CI Reactive Yellow 1, 2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 22, 23, 24, 25, 26, 27, 37, 42, CI Food Yellow 3, 4, CI Solvent Yellow 15, 19, 21, 30, 109.

[0119] Examples of magenta dyes include, but are not limited to, CI Acid Red 1, 6, 8, 9, 13, 14, 18, 26, 27, 32, 35, 37, 42, 51, 52, 57, 75, 77, 80, 82, 85, 87, 88, 89, 92, 94, 97, 106, 111, 114, 115, 117, 118, 119, 129, and 130. , 131, 133, 134, 138, 143, 145, 154, 155, 158, 168, 180, 183, 184, 186, 194, 198, 209, 211, 215, 219, 249, 252, 254, 262, 265, 274, 282, 289, 303, 317, 320, 321, 322, CI Direct Red 1, 2, 4, 9, 11, 13, 17, 20, 23, 24, 28, 31, 33, 37, 39, 44, 46, 62, 63, 75, 79, 80, 81, 83, 84, 89, 95, 99, 113, 197, 201, 218, 220, 224, 225, 226, 227, 228, 229, 230, 231, CI Reactive Red 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 15, 16, 17, 19, 20, 21, 22, 23, 24, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 49, 50, 58, 59, 63, 64, CI Solubilize Red 1, and CI Food Red 7, 9, and 14.

[0120] Examples of cyan dyes include CI Acid Blue 1, 7, 9, 15, 22, 23, 25, 27, 29, 40, 41, 43, 45, 54, 59, 60, 62, 72, 74, 78, 80, 82, 83, 90, 92, 93, 100, 102, 103, 104, 112, 113, 117, 120, 126, 127, 129, 130, and 131. , 138, 140, 142, 143, 151, 154, 158, 161, 166, 167, 168, 170, 171, 182, 183, 184, 187, 192, 199, 203, 204, 205, 229, 234, 236, 249, CI Direct Blue 1, 2, 6, 15, 22, 25, 41, 71, 76, 77, 78, 80, 86 , 87, 90, 98, 106, 108, 120, 123, 158, 160, 163, 165, 168, 192, 193, 194, 195, 196, 199, 200, 201, 202, 203, 207, 225, 226, 236, 237, 246, 248, 249, CI Reactive Blue 1, 2, 3, 4, 5, 7, 8, 9, 13, 1 4, 15, 17, 18, 19, 20, 21, 25, 26, 27, 28, 29, 31, 32, 33, 34, 37, 38, 39, 40, 41, 43, 44, 46, CI Solubilize Bat Blue 1, 5, 41, CI Bat Blue 4, 29, 60, CI Food Blue 1, 2, CI Basic Blue 9, 25, 28, 29, 44.

[0121] Examples of orange dyes include Acid Orange 3, 7, 8, 10, 19, 22, 24, 33, 45, 51, 51S, 56, 67, 74, 80, 86, 87, 88, 89, 94, 95, 107, 108, 116, 122, 127, 140, 142, 144, 149, 152, 156, 162, 166, 168, and Direct Orange. Range 1, 6, 8, 10, 26, 27, 34, 39, 40, 46, 49, 102, 105, 107, 118; Reactive Orange 1, 2, 4, 5, 7, 11, 12, 13, 15, 16, 20, 30, 35, 56, 64, 67, 69, 70, 72, 74, 82, 84, 86, 87, 91, 92, 93, 95, 107.

[0122] The above dyes may be used alone or in combination of two or more kinds.

[0123] Among these, the coloring material is preferably any one of a resin-dispersed pigment, a self-dispersed pigment, and a dye. Such coloring materials can be favorably dispersed in water-based inks, and therefore tend to have improved color development and ejection stability.

[0124] The lower limit of the content of the coloring material is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more, based on the total amount of the color ink composition. When the content of the coloring material is within the above range, the color development tends to be more excellent.

[0125] The upper limit of the colorant content is not particularly limited, but is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, particularly preferably 5% by mass or less, and more particularly preferably 3% by mass or less, relative to the total amount of the color ink composition. When the colorant content is within the above range, the ejection stability tends to be more excellent.

[0126] [First resin particles] The colored ink composition used in the recording method according to this embodiment contains first resin particles, the first resin particles being made of any one of an acrylic resin, a urethane resin, and a polyester resin, and the content of the first resin particles is 3 mass % or more relative to the total mass of the ink composition. This allows the thickness of the ink layer of the colored ink composition on the recording medium to be appropriate, which contributes to improving the abrasion resistance.

[0127] The first resin particles have a function of improving, for example, the adhesion of an image formed by the colored ink composition adhered to a recording medium. The first resin particles are often handled in an emulsion form, but may also be in a powder form.

[0128] Acrylic resin is a general term for polymers obtained by polymerizing at least an acrylic monomer such as (meth)acrylic acid or (meth)acrylic acid ester as one component, and examples thereof include resins obtained from acrylic monomers and copolymers of acrylic monomers and other monomers. Examples thereof include acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers. Examples of vinyl monomers include styrene.

[0129] As the acrylic monomer, acrylamide, acrylonitrile, etc. can also be used. For the resin emulsion using an acrylic resin as a raw material, a commercially available product may be used, and may be selected from, for example, FK-854 (trade name, manufactured by Chuo Rika Kogyo Co., Ltd.), Mowinyl 952B, 718A (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Nipol LX852, LX874 (trade names, manufactured by Nippon Zeon Co., Ltd.), etc.

[0130] In this specification, the acrylic resin may be a styrene-acrylic resin, which will be described later. In addition, in this specification, the term "(meth)acrylic" means acrylic or methacrylic.

[0131] 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-acrylate copolymer, styrene-α-methylstyrene-acrylic acid copolymer, and styrene-α-methylstyrene-acrylic acid-acrylate copolymer. As the styrene-acrylic resin, commercially available products may be used, and for example, JONCRYL 62J, 7100, 390, 711, 511, 7001, 631, 632, 741, 450, 840, 1680, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (trade names, manufactured by BASF), Mowinyl 966A, 975N (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Vinybran 2586 (manufactured by Nissin Chemical Industry Co., Ltd.), etc. may be used.

[0132] The urethane resin is a general term for resins having a urethane bond. In addition to the urethane bond, the urethane resin may be a polyether urethane resin having an ether bond in the main chain, a polyester urethane resin having an ester bond in the main chain, or a polycarbonate urethane resin having a carbonate bond in the main chain. In addition, as the urethane-based resin, commercially available products may be used, such as Superflex 170, 460, 460s, 840, E-4000 (trade names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Rezamin D-1060, D-2020, D-4080, D-4200, D-6300, D-6455 (trade names, manufactured by Dainichi Seiyaku Chemicals Mfg. Co., Ltd.), Takelac WS-6021, W-512-A-6 (trade names, manufactured by Mitsui Chemicals Polyurethanes Inc.), Sancure 2710 (trade name, manufactured by LUBRIZOL), and Parmarin UA-150 (trade name, manufactured by Sanyo Chemical Industries, Ltd.).

[0133] The polyester resin is not particularly limited, but may be, for example, polyethylene terephthalate. As the polyester resin, commercially available products may be used, for example, Elite KA-3556, KA-5071S, KT-8803, KT-9204, KT-8701, KT-8904, KT-0507 (product name, manufactured by Unitika Ltd.) and the like.

[0134] These first resin particles may be used alone or in combination of two or more.

[0135] The glass transition temperature Tg of the first resin particles in the colored ink composition is preferably 50 to 110°C, more preferably 60 to 110°C, even more preferably 70 to 110°C, even more preferably 80 to 110°C, particularly preferably 90 to 110°C, and more particularly preferably 100 to 110°C. The same can be said about the glass transition temperature Tg of the first resin particles in the clear ink composition described below. When the glass transition temperature Tg of the first resin particles in the colored ink composition and the clear ink composition is within the above range, the abrasion resistance tends to be superior. The glass transition point Tg can be confirmed by a standard method using, for example, differential scanning calorimetry (DSC).

[0136] The colored ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition, and is preferably 3 to 20% by mass, more preferably 3 to 15% by mass, even more preferably 3 to 10% by mass, particularly preferably 3 to 8% by mass, and more particularly preferably 4 to 7% by mass. The same can be said about the content of the first resin particles in the clear ink composition described below. When the content of the first resin particles in the colored ink composition and the clear ink composition is within the above range, particularly 3 to 10 mass%, better clogging recovery properties can be obtained and the abrasion resistance tends to be better.

[0137] The content of the first resin particles in the colored ink composition is preferably equal to or greater than the content of the first resin particles in the clear ink composition, which tends to further improve abrasion resistance. From the same viewpoint, the ratio of the content of the first resin particles in the colored ink composition to the content of the first resin particles in the clear ink composition is preferably 1.2 or more, more preferably 1.4 or more, and even more preferably 1.5 or more.

[0138] [Second resin particles] The colored ink composition used in the recording method according to this embodiment contains second resin particles, and the second resin particles are made of a polyolefin resin. It has now been newly discovered that by including second resin particles not only in the clear ink composition but also in the colored ink composition, the slipperiness of the entire printed surface is improved, contributing to improved abrasion resistance.

[0139] The second resin particles have a function of imparting lubricity to an image formed by the ink composition adhered to a recording medium, for example. The second resin particles are often handled in an emulsion form, but may also be in a powder form.

[0140] Examples of polyolefin resins include resins produced from olefins such as ethylene, propylene, and butylene, or derivatives thereof, specifically, polyethylene resins, polypropylene resins, and polybutylene resins.

[0141] Commercially available polyolefin resins include, for example, AQUACER513 (polyethylene resin, average particle size 100 nm to 200 nm, melting point 130° C., solid content 30%), AQUACER series such as AQUACER507, AQUACER515, AQUACER840, and AQUACER1547, HORDAMER PE Examples of the Hi-Tech series include Hi-Tech E-7025P, Hi-Tech E-2213, Hi-Tech E-6500, Hi-Tech E-6314, Hi-Tech E-9460, Hi-Tech E-9015, Hi-Tech E-4A, Hi-Tech E-5403P, Hi-Tech E-8010, and Hi-Tech E-8237 (all product names, manufactured by Toho Chemical Industry Co., Ltd., polyethylene resins), and Nopcoat PEM-17 (product name, manufactured by San Nopco Ltd., polyethylene emulsion, average particle size 40 nm).

[0142] The volume average particle diameter of the second resin particles in the colored ink composition is preferably 30 to 180 nm, more preferably 50 to 180 nm, even more preferably 50 to 150 nm, particularly preferably 50 to 130 nm, and more particularly preferably 60 to 100 nm. The same applies to the volume average particle diameter of the second resin particles in the clear ink composition described below; when the volume average particle diameter of the second resin particles in the colored ink composition and the clear ink composition is within the above range, particularly 30 to 180 nm, the abrasion resistance tends to be superior. The volume average particle diameter can be measured, for example, by a particle size distribution measuring device. Examples of particle size distribution measuring devices include a particle size distribution meter using dynamic light scattering as the measurement principle (for example, the "Nanotrack Series" manufactured by Microtrack Bell). The volume average particle diameter is the D50 value.

[0143] The melting point Tm of the second resin particles in the colored ink composition is preferably from 90 to 150°C, more preferably from 100 to 150°C, even more preferably from 105 to 150°C, and particularly preferably from 110 to 140°C. The same can be said about the melting point Tm of the second resin particles in the clear ink composition described below. When the melting point Tm of the second resin particles in the colored ink composition and the clear ink composition is within the above range, particularly 90 to 150°C, the abrasion resistance tends to be superior. The melting point can be confirmed by a standard method such as differential scanning calorimetry (DSC).

[0144] The content of the second resin particles in the colored ink composition is preferably 0.5 to 5 mass %, more preferably 0.5 to 3 mass %, and even more preferably 0.5 to 1 mass %, relative to the total mass of the ink composition. The same can be said about the content of the second resin particles in the clear ink composition described below. When the content of the second resin particles in the colored ink composition and the clear ink composition is within the above range, particularly 0.5 to 5 mass%, better clogging recovery properties can be obtained and the abrasion resistance tends to be better.

[0145] It is preferable that the content of the second resin particles in the clear ink composition is equal to or greater than the content of the second resin particles in the colored ink composition, which tends to further improve abrasion resistance. From a similar viewpoint, the ratio of the content of the second resin particles in the clear ink composition to the content of the second resin particles in the colored ink composition is preferably 1.5 or more, more preferably 2.0 or more, even more preferably 2.5 or more, and particularly preferably 3.0 or more.

[0146] 〔water〕 The color ink composition used in the recording method according to this embodiment is a water-based ink composition. "Water-based" means that it contains at least water as a solvent component, and may contain water as a main solvent component. The type and content of water are the same as those of the above-mentioned treatment liquid, and will be explained by reading "treatment liquid" as "color ink composition".

[0147] [Poorly water-soluble low-molecular organic compound] The color ink composition used in the recording method according to this embodiment may contain a poorly water-soluble low molecular weight organic compound. The type and content of the poorly water-soluble low molecular weight organic compound may be the same as those of the clear ink composition described below, and will be explained by reading "clear ink composition" as "color ink composition".

[0148] The poorly water-soluble low-molecular-weight organic compound is preferably contained in an amount of 0.05% by mass or more relative to the total mass of the colored ink composition, more preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass, even more preferably 0.2 to 2% by mass, and particularly preferably 0.3 to 1% by mass.

[0149] [Water-soluble low molecular weight organic compound] The color ink composition used in the recording method according to this embodiment may contain a water-soluble low molecular weight organic compound. The type and content of the water-soluble low molecular weight organic compound are the same as those of the treatment liquid described above, and will be explained by reading "treatment liquid" as "color ink composition".

[0150] [Surfactant] The color ink composition used in the recording method according to this embodiment may contain a surfactant. The type and content of the surfactant are the same as those of the treatment liquid described above, and will be explained by reading "treatment liquid" as "color ink composition".

[0151] [Other ingredients] The color ink composition used in the recording method according to this embodiment may contain other components. The other components are the same as those of the treatment liquid described above, and will be explained by reading the "treatment liquid" as the "color ink composition".

[0152] 1.4 Clear ink application process The recording method according to this embodiment includes a clear ink applying step of ejecting a clear ink composition from an inkjet head and applying it to a recording medium.

[0153] 1.4.1 Attachment pattern The amount of the clear ink composition applied is 0.1 to 10.0 mg / inch per unit area of ​​the recording medium. 2 is preferable, and 0.5 to 8.0 mg / inch 2 More preferably, 1.0 to 6.0 mg / inch 2 More preferably, 1.5 to 5.0 mg / inch 2 is particularly preferred, and 2.0 to 4.5 mg / inch 2 More particularly preferably, 2.5 to 4.0 mg / inch 2 is particularly preferred. When the adhesion amount of the clear ink composition is within the above range, better image quality and abrasion resistance tend to be obtained. It is also preferred that the maximum adhesion amount of the color ink composition is within the above adhesion amount range.

[0154] In the recording method according to this embodiment, in the region of the recording medium where the colored ink composition and the clear ink composition are adhered, the amount of the clear ink composition adhered is preferably 10 to 50 mass %, more preferably 20 to 40 mass %, even more preferably 20 to 35 mass %, and particularly preferably 20 to 30 mass %, relative to the amount of the colored ink composition adhered. In this case, the abrasion resistance tends to be more excellent.

[0155] The clear ink application step may be performed before, simultaneously with, or after the above-mentioned ink application step. In particular, the clear ink application step is preferably performed simultaneously with or after the ink application step, and more preferably after the ink application step. This tends to result in better abrasion resistance and image quality.

[0156] An application mode in which the clear ink application step is performed simultaneously with the ink application step can be, for example, when the nozzle surface of the inkjet head has a plurality of nozzle rows along the head movement direction, each nozzle row being made up of a plurality of nozzles arranged in a direction intersecting the direction in which the inkjet head is moved, and when the nozzle row that ejects the clear ink composition is projected along the head movement direction, it can be arranged so that at least a portion of the nozzle row that ejects the colored ink composition overlaps with the nozzle row that ejects the colored ink composition in the nozzle row direction, and it is preferable to arrange them so that they overlap completely.

[0157] An application mode in which the clear ink application step is performed after the ink application step can be achieved, for example, when the nozzle surface of the inkjet head has a plurality of nozzle rows along the head movement direction, each nozzle row being made up of a plurality of nozzles arranged in a direction intersecting the direction in which the inkjet head is moved, and the nozzle row that ejects the clear ink composition is disposed downstream in the transport direction of the recording medium from the nozzle row that ejects the colored ink composition.

[0158] 1.4.2 Clear ink composition The components contained in the clear ink composition used in the clear ink applying step will be described below. The clear ink composition is a water-based ink composition that contains first resin particles and second resin particles.

[0159] [First resin particles] The clear ink composition used in the recording method according to this embodiment contains first resin particles, the first resin particles being made of any one of an acrylic resin, a urethane resin, and a polyester resin, and the content of the first resin particles is 3 mass % or more relative to the total mass of the ink composition. This allows the thickness of the ink layer of the clear ink composition on the recording medium to be appropriate, which contributes to improving abrasion resistance.

[0160] The type and content of the first resin particles are the same as those of the colored ink composition described above, and will be explained by reading "colored ink composition" as "clear ink composition".

[0161] The clear ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition, but it is preferably 3 to 15% by mass, even more preferably 3 to 10% by mass, and particularly preferably 3 to 6% by mass.

[0162] [Second resin particles] The clear ink composition used in the recording method according to this embodiment contains second resin particles, and the second resin particles are made of a polyolefin resin. This improves the slipperiness of the entire printed surface, contributing to improved abrasion resistance.

[0163] The type and content of the second resin particles are the same as those of the above-mentioned colored ink composition, and will be explained by reading "colored ink composition" as "clear ink composition".

[0164] In the clear ink composition, the content of the second resin particles is preferably 0.5 to 5 mass %, more preferably 1 to 5 mass %, and even more preferably 2 to 4 mass %, relative to the total mass of the ink composition.

[0165] 〔water〕 The clear ink composition used in the recording method according to this embodiment is a water-based ink composition. "Water-based" means that it contains at least water as a solvent component, and may contain water as a main solvent component. The type and content of water are the same as those of the above-mentioned treatment liquid, and will be explained by reading "treatment liquid" as "clear ink composition".

[0166] [Poorly water-soluble low-molecular organic compound] The clear ink composition used in the recording method according to this embodiment may contain a poorly water-soluble low-molecular-weight organic compound. The poorly water-soluble low-molecular-weight organic compound may be an organic solvent that is liquid by itself at room temperature, or may be a solid by itself at room temperature. When the clear ink composition contains a poorly water-soluble low-molecular-weight organic compound, the surface tension of the clear ink composition decreases, making it easier for the clear ink composition to wet and spread over the ink layer made of the colored ink composition, and increasing the smoothness of the ink coating surface, which tends to result in better abrasion resistance.

[0167] Here, in the case of a poorly water-soluble low molecular weight organic compound, "poorly water-soluble" means that the solubility is 0.1 to 10 g in 100 g of water at 20° C. The method for determining the solubility of a poorly water-soluble low molecular weight organic compound can be the same as the method for determining the solubility of a water-soluble low molecular weight organic compound described above.

[0168] In the case of a poorly water-soluble low-molecular-weight organic compound, the term "low molecular weight" refers to a molecular weight of 500 or less. The molecular weight is preferably 400 or less, more preferably 300 or less, and further preferably 50 to 200.

[0169] The normal boiling point of the poorly water-soluble low-molecular-weight organic compound is preferably 180 to 300°C, more preferably 200 to 280°C, and even more preferably 230 to 270°C. The melting point of the poorly water-soluble low-molecular-weight organic compound is preferably 130° C. or lower, and more preferably −120° C. or higher, more preferably −50 to 60° C., and even more preferably −30 to 50° C.

[0170] The poorly water-soluble low-molecular-weight organic compound is preferably contained in an amount of 0.1% by mass or more relative to the total mass of the clear ink composition, more preferably 0.1 to 10% by mass, more preferably 0.1 to 5% by mass, even more preferably 0.3 to 3% by mass, and particularly preferably 0.5 to 1.5% by mass.

[0171] The content of the poorly water-soluble low-molecular-weight organic compound in the clear ink composition is preferably equal to or greater than the content of the poorly water-soluble low-molecular-weight organic compound in the colored ink composition, which tends to make the colored ink composition more likely to wet and spread over the ink layer, and to increase the smoothness of the ink coating surface, resulting in better abrasion resistance. From the same viewpoint, the ratio of the content of the poorly water-soluble low molecular weight organic compound in the clear ink composition to the content of the poorly water-soluble low molecular weight organic compound in the colored ink composition is preferably 1.2 or more, more preferably 1.4 or more, even more preferably 1.6 or more, particularly preferably 1.8 or more, and more particularly preferably 2.0 or more.

[0172] The clear ink composition preferably contains a poorly water-soluble low-molecular-weight organic compound selected from alkanediols and glycol ethers. When such a poorly water-soluble low-molecular-weight organic compound is contained, the ink composition tends to have better abrasion resistance.

[0173] (Alkanediols) Examples of the alkanediols include 1,3-alkanediols, other aliphatic diols, and alicyclic diols.

[0174] Examples of 1,3-alkanediols include 2,2-diethyl-1,3-propanediol (DEPOD, boiling point 240° C., solubility 10.0 [g / 100 g water]), 2-methyl-2-propyl-1,3-propanediol (MPPD, boiling point 230° C., melting point 57° C., solubility 7.5 [g / 100 g water]), 2-butyl-2-ethyl-1,3-propanediol (BEPG, boiling point 264° C., melting point 43° C., solubility 0.9 [g / 100 g water]), 2,2-diisobutyl-1,3-propane Examples include diol (DIBPD, boiling point 253°C, melting point 77°C, solubility 0.5 [g / 100g water]), 2,2-dibutyl-1,3-propanediol (DBPD, boiling point 269°C, solubility 0.2 [g / 100g water]), 2,2,4-trimethyl-1,3-pentanediol (TMPD, boiling point 232°C, melting point 54°C, solubility 1.9 [g / 100g water]), and 2-ethyl-1,3-hexanediol (EHD, boiling point 244°C, melting point -40°C, solubility 4.2 [g / 100g water]).

[0175] Other aliphatic diols include, for example, 1,2-octanediol (1,2OD, boiling point 267°C, melting point 26°C, solubility 0.8 [g / 100g water]), 1,9-nonanediol (1,9ND, boiling point 289°C, melting point 46°C, solubility 0.6 [g / 100g water]), and 2,4-diethyl-1,5-pentanediol (DEPD, boiling point 257°C, liquid (25°C), solubility 1.0 [g / 100g water]).

[0176] Examples of alicyclic diols include 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCD, boiling point 220° C., melting point 126° C., solubility 6.1 [g / 100 g water]), 1,4-cyclohexanedimethanol (CHDM, boiling point 286° C., melting point 35° C., solubility 0.8 [g / 100 g water]), and the like.

[0177] Among these alkanediols, the alkanediols represented by the following general formula (1) are preferred. [ka] (In formula (1), R1, R2, and R3 are independently hydrogen or an alkyl group. The total number of carbon atoms in R1, R2, and R3 is 3 to 9.)

[0178] Furthermore, in the above formula, it is preferable that R1 and R2 are not simultaneously hydrogen. When R1, R2, and R3 are alkyl groups, the alkyl groups each independently preferably have 1 to 5 carbon atoms, more preferably 2 to 4 carbon atoms. The total number of carbon atoms of R1, R2, and R3 is preferably 4 to 5, more preferably 4 to 6. It is preferable that R3 is an alkyl group.

[0179] Examples of the alkanediols of the above general formula (1) include 2-methyl-2-propyl-1,3-propanediol (MPPD), 2-butyl-2-ethyl-1,3-propanediol (BEPG), 2,2,4-trimethyl-1,3-pentanediol (TMPD), and 2-ethyl-1,3-hexanediol (EHD).

[0180] (Glycol ethers) Examples of glycol ethers include glycol monoethers and glycol diethers.

[0181] Examples of glycol monoethers include ethylene glycol monohexyl ether (EGHE, boiling point 208°C, melting point -45°C, solubility 1.0 [g / 100g water]), ethylene glycol mono 2-ethylhexyl ether (EHG, boiling point 229°C, melting point -105°C, solubility 0.1 [g / 100g water]), and diethylene glycol monohexyl ether (HDG, boiling point 259°C, liquid (25°C), solubility 1.7 [g / [g / 100g water]), diethylene glycol mono 2-ethylhexyl ether (EHDG, boiling point 277°C, melting point -82°C, solubility 0.5 [g / 100g water]), dipropylene glycol monobutyl ether (BPDG, boiling point 230°C, liquid (25°C), solubility 4.0 [g / 100g water]), and tripropylene glycol monobutyl ether (BPTG, boiling point 276°C, solubility 4.0 [g / 100g water]).

[0182] Examples of glycol diethers include diethylene glycol butyl methyl ether (BMTG, boiling point 212°C, liquid (25°C)), diethylene glycol dibutyl ether (DBDG, boiling point 256°C, melting point -60°C, solubility 0.3 [g / 100 g water]), and the like.

[0183] Among these glycol ethers, glycol ethers having 6 or more carbon atoms are preferred. Examples of glycol ethers having 6 or more carbon atoms include ethylene glycol monohexyl ether (EGHE), ethylene glycol mono 2-ethylhexyl ether (EHG), diethylene glycol monohexyl ether (HDG), diethylene glycol mono 2-ethylhexyl ether (EHDG), dipropylene glycol monobutyl ether (BPDG), tripropylene glycol monobutyl ether (BPTG), diethylene glycol butyl methyl ether (BMTG), and diethylene glycol dibutyl ether (DBDG).

[0184] [Water-soluble low molecular weight organic compound] The clear ink composition used in the recording method according to this embodiment may contain a water-soluble low molecular weight organic compound. The type and content of the water-soluble low molecular weight organic compound are the same as those in the treatment liquid described above, and will be explained by reading "treatment liquid" as "clear ink composition".

[0185] [Surfactant] The clear ink composition used in the recording method according to this embodiment may contain a surfactant. The type and content of the surfactant are the same as those of the treatment liquid described above, and will be explained by reading "treatment liquid" as "clear ink composition".

[0186] [Other ingredients] The clear ink composition used in the recording method according to this embodiment may contain other components. The other components are the same as those in the treatment liquid described above, and will be explained by reading "treatment liquid" as "clear ink composition".

[0187] 1.5 Secondary drying process The recording method according to the present embodiment may further include a secondary drying step of heating the recording medium after the above-mentioned treatment liquid application step, ink application step, and clear ink application step. The secondary drying step can be performed, for example, by using an appropriate heating means. The secondary drying step is preferably performed, for example, by an after-heater (corresponding to the heater 5 in the example of the inkjet recording device described later), and heating is performed after passing through the platen. In addition, the heating means is not limited to the heating means provided in the inkjet recording device, and other drying means may be used. This allows the obtained image to be dried and fixed more sufficiently, so that, for example, the recorded matter can be made usable sooner.

[0188] The surface temperature of the recording medium reached by heating in the secondary drying step is 60.0° C. or more and 120.0° C. or less, preferably 70.0° C. or more and 100.0° C. or less, more preferably 70.0° C. or more and 90° C. or less, and even more preferably 70° C. or more and 80° C. or less. The surface temperature of the recording medium reached by heating in the secondary drying step is particularly preferably 70° C. or more. If the temperature of the recording medium is within this range, the resin particles can be formed into a film and flattened, and the resulting image tends to be dried and fixed more sufficiently.

[0189] 1.6 Other processes The recording method according to the present embodiment may have a primary drying step of drying the recording medium before or at the same time as the above-mentioned treatment liquid application step, ink application step, and clear ink application step. The primary drying step can be performed by a means of stopping recording and leaving it as it is, or by a means of drying using a drying mechanism. Examples of the means of drying using a drying mechanism include a means of blowing room temperature air or hot air to the recording medium (air blowing type), a means of irradiating the recording medium with radiation (infrared rays, etc.) that generates heat (radiation type), a member that contacts the recording medium and transfers heat to the recording medium (conduction type), and a combination of two or more of these means. When the method has a drying step, it is more preferable to perform the drying step using an air blowing type among these.

[0190] Among the primary drying steps, the case where a drying mechanism that heats the recording medium is used as the drying mechanism is particularly called a heating step (primary heating step). For example, among the above drying mechanisms, a drying step that blows air at room temperature does not fall under the category of a heating step.

[0191] The surface temperature of the recording medium in the primary drying step is preferably 60° C. or less, more preferably 50° C. or less, and even more preferably 40° C. or less. The lower limit is preferably 20° C. or more, more preferably 25° C. or more, and even more preferably 30° C. or more. This tends to result in better abrasion resistance.

[0192] 2. Recording device A recording apparatus according to one embodiment of the present invention is a recording apparatus that records on a recording medium by the recording method described above, and has a treatment liquid, a colored ink composition, a clear ink composition, a treatment liquid application mechanism that applies the treatment liquid, an inkjet head that ejects the colored ink composition, and an inkjet head that ejects the clear ink composition.

[0193] According to the recording apparatus of this embodiment, recording is performed by the above-mentioned recording method, so that it is possible to obtain excellent abrasion resistance and image quality.

[0194] The treatment liquid, color ink composition, and clear ink composition of the recording apparatus according to this embodiment are as described above, and therefore will not be described here. An example of the recording apparatus according to this embodiment will be described below with reference to the drawings.

[0195] 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 pre-heater 7, a ventilation fan 8, a carriage 9, a platen 11, a carriage moving mechanism 13, a transport means 14, and a control unit CONT. In the inkjet recording apparatus 1, the control unit CONT shown in Fig. 2 controls the operation of the entire inkjet recording apparatus 1.

[0196] The inkjet head 2 includes an inkjet head 2b that ejects a colored ink composition and an inkjet head 2c 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.

[0197] As a treatment liquid application mechanism for applying the treatment liquid, for example, a roller, a spray, an inkjet head, or the like can be used. Among these, it is preferable to apply the treatment liquid to the recording medium by an inkjet method using an inkjet head. Therefore, the inkjet head 2 may include an inkjet head 2a that ejects the treatment liquid.

[0198] In this embodiment, the inkjet head 2 is a serial type inkjet head that scans multiple times in the main scanning direction relative to the recording medium M to deposit the colored ink composition, the clear ink composition and the treatment liquid (hereinafter also referred to as "ink, etc.") 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 referred to as main scanning.

[0199] Fig. 3 shows an arrangement in which an inkjet head 2a that ejects a treatment liquid and an inkjet head 2c that ejects a clear ink composition are aligned horizontally at the same position as an inkjet head 2b that ejects a colored ink composition in the transport direction (direction T2) of a recording medium M. With such an arrangement, the treatment liquid application step, ink application step, and clear ink application step in the above-mentioned recording method can be performed simultaneously. Note that the nozzle rows shown in Fig. 3 are nozzle rows that eject ink, etc. in each inkjet head.

[0200] 4 shows an arrangement in which an inkjet head 2a that ejects a treatment liquid is aligned horizontally at the same position as an inkjet head 2b that ejects a colored ink composition in the transport direction (direction T2) of a recording medium M, and an inkjet head 2c that ejects a clear ink composition is arranged downstream of the inkjet head 2b that ejects a colored ink composition in the transport direction (direction T2) of a recording medium M. With such an arrangement, the treatment liquid application step and the ink application step in the above-mentioned recording method can be performed simultaneously, and the clear ink application step can be performed after the ink application step. Note that the nozzle rows shown in FIG. 4 are nozzle rows that eject ink, etc. in each inkjet head.

[0201] Here, the main scanning direction is the direction in which the carriage 9 carrying the inkjet head 2 moves. In FIG. 1, it is the direction intersecting 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, that is, the direction indicated by S1-S2, is the main scanning direction MS, and the direction indicated by T1→T2 is the sub-scanning direction SS. Note that scanning is performed in the main scanning direction, that is, in either the direction indicated by the arrow S1 or the arrow S2, in one scan. Then, recording is performed on the recording medium M by repeating the main scan of the inkjet head 2 and the sub-scan, which is the transport of the recording medium M, multiple times. That is, the color ink applying process and the clear ink applying process, and the treatment liquid applying process, if necessary, 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 intersecting the main scanning direction.

[0202] The cartridge 12 that supplies each ink, etc. and treatment liquid to the inkjet head 2 includes a plurality of independent cartridges. The cartridge 12 is detachably mounted to the carriage 9 on which the inkjet head 2 is mounted. Each of the plurality of cartridges can be filled with a different type of ink, etc., and the ink, etc. is supplied from the cartridge 12 to each nozzle. Note that, although an example in which the cartridge 12 is mounted on the carriage 9 is shown in this embodiment, the present invention is not limited to this, and the cartridge 12 may be provided in a location other than the carriage 9 and may supply ink to each nozzle by a supply pipe (not shown).

[0203] 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.

[0204] The inkjet recording apparatus 1 is equipped with a ventilation fan 8, an IR heater 3, and a platen heater 4 for drying ink and the like discharged from the inkjet head 2 and attached to the recording medium M. A 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.

[0205] When the IR heater 3 is used, the recording medium M can be radiatively heated by radiating infrared rays from the inkjet head 2 side. This makes it easy for the inkjet head 2 to heat at the same time, but compared to heating from the back side of the recording medium M by the platen heater 4 or the like, the temperature can be increased without being affected by the thickness of the recording medium M. In addition, various fans (for example, ventilation fan 8) may be provided to blow hot air or air at the same temperature as the environment onto the recording medium M to dry the ink on the recording medium M.

[0206] 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, etc., ejected by the inkjet head 2 can be dried quickly from the time it is applied to the recording medium M. The platen heater 4 can heat the recording medium M by conduction, thereby allowing the ink, etc. to be applied to the heated recording medium M.

[0207] The upper limit of the surface temperature of the recording medium M caused by heating by the IR heater 3 and the platen heater 4 is preferably 50° C. or less, more preferably 45° C. or less, and further preferably 40° C. or less. The lower limit of the surface temperature of the recording medium M is preferably 25° C. or more.

[0208] The heater 5 is a heater for drying and solidifying the ink and the like attached to the recording medium M, that is, for secondary heating or secondary drying. The heater 5 can be used in the secondary drying process. When the heater 5 heats the recording medium M on which an image is recorded, the moisture and the like contained in the ink and the like 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 on the recording medium M, resulting in excellent film-forming properties, and an excellent high-quality image can be obtained in a short time.

[0209] The upper limit of the surface temperature of the recording medium M heated by the heater 5 is preferably 120° C. or less, more preferably 100° C. or less, and even more preferably 80° C. or less. The lower limit of the surface temperature of the recording medium M is preferably 50° C. or more, more preferably 60° C. or more, and even more preferably 70° C. or more. By keeping the temperature within the above range, a high-quality image tends to be obtained in a short time.

[0210] The inkjet recording apparatus 1 may have a cooling fan 6. After the ink recorded on the recording medium M is dried, the ink on the recording medium M is cooled by the cooling fan 6, whereby an ink coating film with good adhesion can be formed on the recording medium M.

[0211] The inkjet recording apparatus 1 may also include a preheater 7 that preheats the recording medium M before ink or the like is applied to the recording medium M. Furthermore, the inkjet recording apparatus 1 may also include a ventilation fan 8 so that the ink or the like applied to the recording medium M can be dried more efficiently.

[0212] Below the carriage 9, there are provided a platen 11 that supports the recording medium M, a carriage movement mechanism 13 that moves the carriage 9 relatively to the recording medium M, and a transport means 14 that is a roller that transports the recording medium M in the sub-scanning direction. The operations of the carriage movement mechanism 13 and the transport means 14 are controlled by a control unit CONT.

[0213] 3. Working Example The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following, "%" is based on mass unless otherwise specified.

[0214] 3.1 Preparation of treatment liquid, colored ink composition, and clear ink composition The treatment liquid, colored ink composition and clear ink composition used in each Example or Comparative Example were obtained by placing each component in a container so as to obtain the composition shown in Table 1 (Figure 5) for the treatment liquid, Table 2 (Figure 6) for the colored ink composition and Table 3 (Figure 7) for the clear ink composition, adding pure water so that the total amount of each composition was 100 mass%, mixing and stirring for 2 hours with a magnetic stirrer, and then further mixing thoroughly by dispersing using a bead mill filled with zirconia beads having a diameter of 0.3 mm, stirring for 1 hour and then filtering using a 5 μm PTFE membrane filter.

[0215] For the colored ink compositions, an aqueous pigment dispersion was prepared in advance as follows, and this was used in the preparation of the inks. A reaction vessel equipped with a reflux condenser, a gas inlet, a thermometer, and a stirrer was charged with 198.2 parts of diethylene glycol monobutyl ether, 1.0 part of iodine, 3.7 parts of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 66.1 parts of tricyclodecyl methacrylate, and 0.17 parts of diphenylmethane as a catalyst. Polymerization was carried out at 45°C for 5 hours while flowing nitrogen, to obtain a solution of polymer block A. Next, the polymerization temperature was lowered to 40°C, and 44.0 parts of tricyclodecyl methacrylate, 17.2 parts of methacrylic acid, and 1.2 parts of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) were added to the solution of the A polymer block obtained above. Polymerization was carried out for 4 hours, and then the mixture was heated to 70°C and polymerized for 1 hour to form a B polymer block, thereby obtaining a solution of an AB block polymer. The AB block polymer solution obtained above was cooled, and then 66.1 parts of diethylene glycol monobutyl ether was added thereto. After drying at 150° C. for 1 hour, a polymer with a solid content of 33.0% was obtained. 341 parts of the above polymer, 163.6 parts of butyl carbitol, and 450 parts of CI Pigment Blue 15:3, a cyan pigment, were mixed and stirred with a disperser. The pigment was then thoroughly dispersed with a horizontal media disperser to obtain an oil-based pigment dispersion. Next, while stirring 700 parts of the oil-based pigment dispersion obtained above with a disperser, a mixed liquid consisting of 4.0 parts of potassium hydroxide and 341 parts of water was gradually added to neutralize and cause phase inversion. Next, the pigment was thoroughly dispersed again with a horizontal media disperser to obtain an aqueous pigment dispersion.

[0216] The following supplementary explanations are provided for the descriptions in Tables 1 to 3 (FIGS. 5 to 7). <Water-soluble low molecular weight organic compounds> ·PG (Propylene glycol, standard boiling point 188℃, 25℃ properties: liquid) <Poorly water-soluble low molecular weight organic compounds> ·BEPG (Butyl Ethyl Propanediol, normal boiling point 264℃, 25℃ properties: solid) <Surfactants> BYK-348 (product name of BYK Japan Co., Ltd., silicone-based surfactant) <Flocculant> · Catiomaster PD-7 (product name of Yokkaichi Chemical Co., Ltd., amine-epichlorohydrin copolymer cationic resin) <First resin particles> Joncryl 631 (BASF Japan Ltd. product name, acrylic resin emulsion) Joncryl 1680 (BASF Japan Ltd. product name, acrylic resin emulsion) Superflex 170 (product name of Daiichi Kogyo Seiyaku Co., Ltd., urethane resin emulsion) Elitel KA-3556 (product name of Unitika Ltd., polyester resin emulsion) <Second resin particles> - Hi-Tec E-6314 (product name of Toho Chemical Industry Co., Ltd., polyethylene wax emulsion) - Hi-Tec E-6500 (product name of Toho Chemical Industry Co., Ltd., polyethylene wax emulsion) - Hi-Tec E-8010 (product name of Toho Chemical Industry Co., Ltd., polyethylene wax emulsion) HORDAMER PE 03 (product name of BYK Japan Co., Ltd., polyethylene wax emulsion) The "particle size" refers to the volume average particle size.

[0217] 3.2 Recording conditions The conditions for recording in the evaluation test were as follows. Printing machine: SC-R5050 (modified machine manufactured by Seiko Epson Corporation) Resolution: 1200 x 1200 dpi Print pattern: Solid pattern (cyan) Number of scans: 9 Paper surface temperature: 40℃ Secondary drying temperature: 80℃ Platen gap: 1.7mm

[0218] The "paper surface temperature" refers to the surface temperature of the recording medium located opposite the inkjet head, and the "secondary drying temperature" refers to the surface temperature of the recording medium after it has passed through the platen and undergone the secondary drying process.

[0219] 3.3 Evaluation Test 3.3.1 Scratch resistance The treatment liquid, colored ink composition, and clear ink composition obtained above were filled into SC-R5050, and a solid pattern (color ink deposition amount 16 mg / inch) was printed on a recording medium. 2 The ink was printed with the same amount of ink as the original (the amount of treatment liquid and clear ink attached is shown in Table 4). After leaving it at room temperature for 30 minutes, the ink-attached area was cut into a 30 x 150 mm rectangle and rubbed 50 times with a plain woven cloth using a Gakushin-type abrasion resistance tester (load 500 g), after which the degree of ink peeling was visually evaluated. (Judgment criteria) AA: No peeling A: Less than 20% of the evaluation area has peeled off B: Peeling occurs in 20% to less than 50% of the evaluation area C: More than 50% of the evaluation area has peeled off.

[0220] 3.3.2 Image Quality (Uneven Banding) The treatment liquid, color ink composition, and clear ink composition obtained above were filled into SC-R5050, a recording medium was set, and a solid pattern (color ink deposition amount 16 mg / inch 2 The amount of treatment liquid and clear ink attached was shown in Table 4) and the print was visually observed. (Judgment criteria) A: No visible stripes of uneven density (banding) extending in the main scanning direction B: There is some banding unevenness, but the density difference is small and not noticeable. C: Banding is uneven, and the density difference is large and noticeable.

[0221] 3.3.3 Clogging recovery After filling the SC-R5050 with the colored ink composition and clear ink composition obtained above, the nozzle surface was struck with a water-moistened Bemcot to intentionally cause nozzles to miss. In this state, the printer was left idle for 2 hours in an environment of 40°C and 15% humidity. After recording, cleaning was performed three times, and the number of unrecovered nozzles was counted. In one cleaning, 1 g of ink was discharged from the nozzle group. The nozzle group was composed of 800 nozzles. The treatment liquid was excluded from the evaluation. (Judgment criteria) AA: No nozzle non-ejection A: Nozzle non-ejection rate less than 1% B: Nozzle non-ejection rate: 1% to 3% C: Nozzle non-ejection rate 3% or more

[0222] 3.3.4 Long-term storage stability The colored ink composition and the clear ink composition obtained above were sealed in an aluminum pack to prevent air bubbles from being mixed in, and then the pack was placed in a centrifuge CF9RX (manufactured by Hitachi Koki Co., Ltd.) and centrifuged at 500 rpm for 120 hours. After that, (1) they were left as they were, and (2) they were stirred 30 times back and forth. Then, each pack was opened and visually checked to see if the resin had separated. When the resin separated, the polyolefin resin (second resin particles) with a low specific gravity floated to the top of the ink and appeared to have separated. (Judgment criteria) A: No resin separation occurs even when opened as is B: When opened as is, separation of the resin occurs, but this is resolved after 30 back and forth agitation. C: Resin separation occurs even after 30 times of back and forth stirring.

[0223] 3.4 Evaluation results The evaluation results are shown in Table 4 (FIG. 8).

[0224] In Table 4 (FIG. 8), "Arrangement 1" is the inkjet head arrangement shown in FIG. 4, in which the ink application step and the treatment liquid application step are performed simultaneously, and the clear ink application step is performed after the ink application step. "Arrangement 2" is the inkjet head arrangement shown in FIG. 3, in which the clear ink application step, the ink application step, and the treatment liquid application step are performed simultaneously. In addition, in Table 4 (FIG. 8), "M1" represents PRSO401F (product name of Lintec Sign Systems Co., Ltd., vinyl chloride wallpaper, Sa=3.3 μm). "M2" represents DV662 (product name of Naeschen, non-vinyl chloride wallpaper, Sa=1.7 μm). "M3" represents Orajet 3165G-010 (product name of Orafor Japan Co., Ltd., vinyl chloride film, Sa=0.3 μm). The surface roughness Sa was measured using a laser microscope (VK-X1000 / Keyence) according to a method compliant with ISO25178. The objective lens magnification was 20 times, and the average value of n=3 measurements was used.

[0225] From the results shown in Table 4 (FIG. 8), a recording method for recording on a recording medium having a surface roughness Sa of 1 μm or more and low absorbency or non-absorbency includes a treatment liquid applying step of applying a treatment liquid containing a flocculant to the recording medium, an ink applying step of ejecting a colored ink composition from an inkjet head to apply it to the recording medium, and a clear ink applying step of ejecting a clear ink composition from an inkjet head to apply it to the recording medium, and the colored ink composition is a water-based ink composition containing a colorant, first resin particles, and second resin particles. The clear ink composition is a water-based ink composition containing first resin particles and second resin particles, the first resin particles being made of any one of an acrylic resin, a urethane resin, or a polyester resin, and the second resin particles being made of a polyolefin resin, the colored ink composition having a first resin particle content of 3 mass% or more relative to the total mass of the ink composition, and the clear ink composition having a first resin particle content of 3 mass% or more relative to the total mass of the ink composition. It was found that the recording methods according to each of the examples provided recorded products with excellent abrasion resistance and image quality.

[0226] In contrast, in the recording methods according to the comparative examples that did not satisfy the above-mentioned configuration, at least one of the abrasion resistance and image quality of the recorded matter was poor. Note that in the recording method according to the reference example that used a recording medium with a surface roughness Sa of less than 1 μm, the problem of the present invention did not occur.

[0227] The following can be derived from the above-described embodiment.

[0228] One aspect of the recording method is A recording method for recording on a recording medium having a surface roughness Sa of 1 μm or more and low absorbency or non-absorbency, comprising the steps of: a treatment liquid applying step of applying a treatment liquid containing a flocculant to the recording medium; an ink depositing step of ejecting a colored ink composition from an inkjet head and depositing the colored ink composition on the recording medium; a clear ink applying step of ejecting a clear ink composition from an inkjet head and applying the clear ink composition to the recording medium, the colored ink composition is a water-based ink composition containing a color material, first resin particles, and second resin particles; the clear ink composition is a water-based ink composition containing first resin particles and second resin particles, the first resin particles are made of any one of an acrylic resin, a urethane resin, and a polyester resin; the second resin particles are made of a polyolefin resin, the content of the first resin particles in the colored ink composition is 3% by mass or more based on the total mass of the ink composition; The clear ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition.

[0229] In one embodiment of the recording method, The content of the first resin particles in the colored ink composition may be 3 to 10% by mass with respect to the total mass of the ink composition. The clear ink composition may have a content of the first resin particles of 3 to 10% by mass relative to the total mass of the ink composition.

[0230] In any one of the above recording methods, The content of the first resin particles in the colored ink composition may be equal to or greater than the content of the first resin particles in the clear ink composition.

[0231] In any one of the above recording methods, The content of the second resin particles in the colored ink composition may be 0.5 to 5% by mass with respect to the total mass of the ink composition. The clear ink composition may have a content of the second resin particles of 0.5 to 5% by mass relative to the total mass of the ink composition.

[0232] In any one of the above recording methods, The content of the second resin particles in the clear ink composition may be equal to or greater than the content of the second resin particles in the colored ink composition.

[0233] In any one of the above recording methods, The glass transition temperature Tg of the first resin particles in the colored ink composition may be 50 to 110° C., The first resin particles in the clear ink composition may have a glass transition temperature Tg of 50 to 110°C.

[0234] In any one of the above recording methods, The second resin particles in the colored ink composition may have a volume average particle diameter of 30 to 180 nm, The second resin particles in the clear ink composition may have a volume average particle diameter of 30 to 180 nm.

[0235] In any one of the above recording methods, The melting point Tm of the second resin particles in the colored ink composition may be 90 to 150° C., The second resin particles in the clear ink composition may have a melting point Tm of 90 to 150°C.

[0236] In any one of the above recording methods, The clear ink composition may contain a poorly water-soluble low-molecular-weight organic compound selected from alkanediols and glycol ethers.

[0237] In any one of the above recording methods, The content of the poorly water-soluble low-molecular-weight organic compound in the clear ink composition may be equal to or greater than the content of the poorly water-soluble low-molecular-weight organic compound in the colored ink composition.

[0238] In any one of the above recording methods, In the area of ​​the recording medium to which the color ink composition and the clear ink composition are applied, The amount of the clear ink composition adhered may be 10 to 50% by mass relative to the amount of the colored ink composition adhered.

[0239] In any one of the above recording methods, The clear ink applying step may be performed after the ink applying step.

[0240] In any one of the above recording methods, The recording medium may be wallpaper.

[0241] One aspect of the recording device is A recording apparatus for recording on the recording medium by the recording method according to any one of the above aspects, The ink jet head includes the treatment liquid, the colored ink composition, the clear ink composition, a treatment liquid application mechanism that applies the treatment liquid, an inkjet head that ejects the colored ink composition, and an inkjet head that ejects the clear ink composition.

[0242] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiment, for example, a configuration that has the same function, method, and result, or a configuration that has the same purpose and effect. The present invention also includes a configuration in which non-essential parts of the configuration described in the embodiment are replaced. The present invention also includes a configuration that has the same action and effect as the configuration described in the embodiment, or a configuration that can achieve the same purpose. The present invention also includes a configuration in which publicly known technology is added to the configuration described in the embodiment. [Explanation of symbols]

[0243] Reference Signs List 1...inkjet recording device, 2...inkjet head (2a...inkjet head that ejects treatment liquid, 2b...inkjet head that ejects colored ink composition, 2c...inkjet head that ejects clear ink composition), 3...IR heater, 4...platen heater, 5...heating heater, 6...cooling fan, 7...pre-heater, 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. A recording method for recording on a recording medium having a surface roughness Sa of 1 μm or more and low absorbency or non-absorbency, comprising the steps of: a treatment liquid applying step of applying a treatment liquid containing a flocculant to the recording medium; an ink depositing step of ejecting a colored ink composition from an inkjet head and depositing the colored ink composition on the recording medium; a clear ink applying step of ejecting a clear ink composition from an inkjet head and applying the clear ink composition to the recording medium, the color ink composition is a water-based ink composition containing a color material, first resin particles, and second resin particles; the clear ink composition is a water-based ink composition containing first resin particles and second resin particles, the first resin particles are made of any one of an acrylic resin, a urethane resin, and a polyester resin; the second resin particles are made of a polyolefin resin, the content of the first resin particles in the colored ink composition is 3% by mass or more based on the total mass of the ink composition, The clear ink composition has a content of the first resin particles of 3% by mass or more relative to the total mass of the ink composition.

2. the content of the first resin particles in the colored ink composition is 3% by mass to 10% by mass with respect to the total mass of the ink composition; The recording method according to claim 1, wherein the clear ink composition has a content of the first resin particles of 3 to 10% by mass with respect to the total mass of the ink composition.

3. The recording method according to claim 1 , wherein a content of the first resin particles in the colored ink composition is equal to or greater than a content of the first resin particles in the clear ink composition.

4. the content of the second resin particles in the colored ink composition is 0.5 to 5% by mass with respect to the total mass of the ink composition; 3. The recording method according to claim 1, wherein the content of the second resin particles in the clear ink composition is 0.5 to 5% by mass with respect to the total mass of the ink composition.

5. The recording method according to claim 1 , wherein the content of the second resin particles in the clear ink composition is equal to or greater than the content of the second resin particles in the colored ink composition.

6. the glass transition temperature Tg of the first resin particles in the colored ink composition is 50 to 110° C., 3. The recording method according to claim 1, wherein the first resin particles in the clear ink composition have a glass transition temperature Tg of 50 to 110° C.

7. the second resin particles in the colored ink composition have a volume average particle diameter of 30 to 180 nm; 3. The recording method according to claim 1, wherein the second resin particles in the clear ink composition have a volume average particle diameter of 30 to 180 nm.

8. the melting point Tm of the second resin particles in the colored ink composition is 90 to 150° C., 3. The recording method according to claim 1, wherein the melting point Tm of the second resin particles in the clear ink composition is 90 to 150° C.

9. The recording method according to claim 1 or 2, wherein the clear ink composition contains a poorly water-soluble low-molecular-weight organic compound selected from alkanediols and glycol ethers.

10. The recording method according to claim 9 , wherein the content of the poorly water-soluble low-molecular-weight organic compound in the clear ink composition is equal to or greater than the content of the poorly water-soluble low-molecular-weight organic compound in the colored ink composition.

11. In the area of ​​the recording medium to which the color ink composition and the clear ink composition are applied, 3. The recording method according to claim 1, wherein the amount of the clear ink composition adhered is 10 to 50% by mass relative to the amount of the colored ink composition adhered.

12. The recording method according to claim 1 , wherein the clear ink applying step is performed after the ink applying step.

13. 3. The recording method according to claim 1, wherein the recording medium is wallpaper.

14. A recording apparatus for recording on the recording medium according to the recording method of claim 1, a treatment liquid deposition mechanism that deposits the treatment liquid, an inkjet head that ejects the colored ink composition, and an inkjet head that ejects the clear ink composition.

Images