Recording method, recording apparatus, and ink set

Abstract

To provide a recording method in which graininess, coverage pinholes, and density unevenness of a formed image are favorable.SOLUTION: A recording method comprises: a treatment solution attachment step in which a treatment solution is attached to a recording medium; a first ink attachment step in which a first ink composition is ejected and attached to the recording medium; and a second ink attachment step in which a second ink composition is ejected and attached to the recording medium, wherein the treatment solution is a water-based treatment solution containing a coagulant, the first ink composition and the second ink composition are water-based ink compositions each containing a colorant, and in a scan in which relative positions of an ink jet head and the recording medium are moved, the treatment solution, the first ink composition, and the second ink composition are attached to the recording medium to the same scan area during the same scan, a duration from the landing of a solution droplet of the treatment solution on the recording medium to the landing of an ink droplet of the first ink composition on the recording medium is 0.15 seconds or more and 0.25 seconds or less, and a duration from the landing of the solution droplet of the treatment solution on the recording medium to the landing of an ink droplet of the second ink composition on the recording medium is 0.3 seconds or more and 0.6 seconds or less, the treatment solution containing a silicone surfactant, the silicone surfactant including a silicone surfactant a, for which a surface tension of a 0.1 mass% aqueous solution of the surfactant is 28.0 mN / m or less and a surface tension of a 0.1 mass% propylene glycol solution of the surfactant is 28.0 mN / m or less.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In inkjet printing on low-absorbency media using aqueous inks, the use of a treatment liquid to fix the ink early and improve image quality (reduce bleeding) has been studied. Such a printing method has also been studied for use in line-type and serial-type printing devices.

[0003] For example, Patent Document 1 discloses a recording method using a line-type recording device that performs recording by scanning a plurality of line heads, each having a width equal to or greater than the recording width of the recording medium, relatively once across the recording medium, the recording method including a treatment liquid application step of applying a treatment liquid containing an aggregating agent to the recording medium, and an ink application step of ejecting a colored ink composition from the line heads and applying it to the recording medium. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-138417 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when using a plurality of inks, if some inks have a relatively short time between the time the treatment liquid lands and the time the ink lands, and other inks have a relatively long time, there is a problem of poor graininess and uneven density in the formed image. [Means for solving the problem]

[0006] One aspect of the recording method according to the present invention is to a treatment liquid application step of ejecting the treatment liquid from an inkjet head and applying it to the recording medium; a first ink deposition step of ejecting the first ink composition from an inkjet head and depositing it on a recording medium; a second ink deposition step of ejecting the second ink composition from an inkjet head and depositing it on a recording medium, the treatment liquid is an aqueous treatment liquid containing a flocculant, the first ink composition and the second ink composition are water-based ink compositions containing a coloring material, In a scanning operation in which the relative positions of the inkjet head and the recording medium are moved, the treatment liquid, the first ink composition, and the second ink composition are deposited on the recording medium in the same scanning operation for the same scanning region; the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less; the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less; the treatment liquid contains a silicone surfactant, The silicone surfactant includes a silicone surfactant a, The silicone surfactant a is a silicone surfactant in which the surface tension of a 0.1% by mass aqueous solution of the surfactant is 28.0 mN / m or less, and the surface tension of a 0.1% by mass propylene glycol solution of the surfactant is 28.0 mN / m or less.

[0007] One aspect of the recording device according to the present invention is A recording device that performs the above-mentioned recording method, the treatment liquid, the first ink composition, and the second ink composition; an inkjet head that ejects the treatment liquid, the first ink composition, and the second ink composition; It has.

[0008] Furthermore, one aspect of the ink set according to the present invention is used in the above-described recording method, and includes the above-described treatment liquid, the above-described first ink composition, and the above-described second ink composition.

[0009] Furthermore, one aspect of the treatment liquid according to the present invention is A processing liquid used in the above-mentioned recording method, The treatment liquid is an aqueous solution containing a flocculant, Contains silicone surfactants, The silicone surfactant includes a silicone surfactant a, The silicone surfactant a is a silicone surfactant in which the surface tension of a 0.1% by mass aqueous solution of the surfactant is 28.0 mN / m or less, and the surface tension of a 0.1% by mass propylene glycol solution of the surfactant is 28.0 mN / m or less. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a serial inkjet recording apparatus. [Figure 2] FIG. 1 is a perspective view showing an example of a configuration around a carriage of a serial type inkjet recording apparatus. [Figure 3] FIG. 2 is a schematic diagram showing an example of an arrangement of inkjet heads. [Figure 4] FIG. 10 is a front view schematically illustrating an example of another serial type recording apparatus. [Figure 5] FIG. 10 is a bottom view partially showing another configuration of the inkjet head. [Figure 6] FIG. 10 is a bottom view partially showing still another configuration of the inkjet head. [Figure 7] FIG. 1 is a schematic cross-sectional view showing a line-type inkjet recording apparatus. [Figure 8] Table 1 shows the compositions of the treatment solutions used in the examples and comparative examples. [Figure 9] Table 2 shows the compositions of the first ink and the second ink used in the examples and comparative examples. [Figure 10] Table 3 shows the conditions and evaluation results of the examples. [Figure 11] Table 4 shows the conditions and evaluation results of the examples. [Figure 12] Table 5 shows the conditions and evaluation results of the comparative example. [Figure 13] Table 6 shows the physical properties of surfactants used in the examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below. 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 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. Furthermore, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits.

[0012] 1. Recording method The recording method according to this embodiment includes a treatment liquid application step of ejecting a treatment liquid from an inkjet head and applying it to a recording medium, a first ink application step of ejecting a first ink composition from an inkjet head and applying it to a recording medium, and a second ink application step of ejecting a second ink composition from an inkjet head and applying it to a recording medium.

[0013] When the overall length of the inkjet head of a recording apparatus in the scanning direction is long, the time from when the treatment liquid lands to when the ink lands may be long. For example, when using an inkjet head with a relatively long nozzle row, such an inkjet head may be configured by combining multiple unit heads (unit nozzle rows) with relatively short nozzle rows. In such an inkjet head, the unit heads (unit nozzle rows) have portions that are positioned differently from one another in the scanning direction.

[0014] For example, it is an inkjet head made up of a plurality of unit heads arranged in a staggered manner.

[0015] Such an inkjet head may be, for example, an inkjet head (long head) having a length equal to or greater than the width of the recording area of ​​the recording medium in a direction intersecting the scanning direction, which increases the overall length of the inkjet head in the scanning direction. Furthermore, when a relatively large number of inks are used for printing, or when the distance between inkjet heads in the scanning direction is long, the overall length of the inkjet heads in the printing apparatus in the scanning direction also becomes long.

[0016] In such a case, when ink is ejected from a nozzle row that is positioned far away from the nozzle row that ejects the treatment liquid, the time from when the treatment liquid lands until when the ink lands becomes long.

[0017] On the other hand, ink ejected from a nozzle array closer to the nozzle array ejecting the treatment liquid lands sooner after the treatment liquid lands. Therefore, during the same scan of the same scanning area, there is a large difference in the time from when the treatment liquid lands to when the ink lands between the ink ejected from the nozzles closer to the treatment liquid nozzles and the ink ejected from the nozzles farther from the treatment liquid nozzles. This phenomenon is more likely to occur when there are a large number of ink droplets or when the intervals between the nozzle arrays are wide. Furthermore, this phenomenon can occur in both line-type and serial-type printing.

[0018] When the time difference described above occurs, there are problems with the formed image, such as poor graininess, unevenness in shading, and poor filling. In contrast, the printing method of this embodiment provides excellent image graininess, unevenness in shading, and excellent filling.

[0019] 1.1. Treatment liquid application process In the treatment liquid application step, the treatment liquid is ejected from an inkjet head and applied to the recording medium.

[0020] 1.1.1. Recording medium The recording medium on which an image is formed using the recording method of this embodiment may or may not have an ink-absorbing recording surface. Therefore, the recording medium is not particularly limited, and examples include liquid-absorbent recording media such as paper, film, and cloth; low-absorbent recording media such as printing paper; and non-liquid-absorbent recording media such as metal, glass, and polymers. Even with such recording media, which are prone to graininess, the recording method of this embodiment can further suppress the graininess of the image.

[0021] A low liquid absorbency or non-liquid absorbent recording medium refers to a recording medium that does not absorb ink at all or absorbs very little ink. Quantitatively, a non-liquid absorbent or low liquid absorbent recording medium is one that absorbs ink within 30 msec from the start of contact in the Bristow method. 1 / 2 Water absorption up to 10mL / m 2 This Bristow method is the most widely used method for measuring the amount of liquid absorption in a short period of time, and is also adopted by the Japan Pulp and Paper Technology Association (JAPAN TAPPI). For details of the test method, see "JAPA This is described in Standard No. 51 "Paper and Paperboard - Liquid Absorbency Test Method - Bristow Method" of the "N TAPPI Paper and Pulp Test Methods 2000 Edition." In contrast, a liquid-absorbent recording medium refers to a recording medium that does not fall under the category of non-liquid-absorbent or low-liquid-absorbent. In this specification, low-liquid-absorbent and non-liquid-absorbent may be simply referred to as low-absorbent and non-absorbent.

[0022] Examples of non-liquid-absorbent recording media include those in which a plastic is coated on a substrate such as paper, those in which a plastic film is adhered to a substrate such as paper, and plastic films that do not have an absorption layer (receptor layer). Examples of plastics include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

[0023] Furthermore, examples of low-liquid-absorbency recording media include recording media having a low-liquid-absorbency coating layer on the surface, such as so-called coated paper. For example, recording media having a paper substrate include printing paper such as art paper, coated paper, and matte paper. For example, recording media having a plastic film substrate include those having a polymer or the like coated on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, or the like, and those having particles of silica, titanium, or the like coated together with a binder.

[0024] A liquid-absorbent recording medium can also be used as the recording medium. The liquid-absorbent recording medium is a recording medium that is absorbed within 30 msec from the start of contact in the Bristow method described above. 1 / 2 Water absorption up to 10mL / m 2 It refers to a "super recording medium."

[0025] Examples of liquid-absorbent recording media include those that have a liquid-absorbing receiving layer provided on the surface of the recording medium. For example, inkjet paper (paper specifically for inkjet printers) is one example. Examples of liquid-absorbent receiving layers include layers made of liquid-absorbent resins, liquid-absorbent inorganic fine particles, etc.

[0026] Liquid-absorbent recording media include recording media whose substrate itself is liquid-absorbent. Examples include fabrics made of fibers and paper made of pulp. Examples of paper include plain paper, cardboard, and liner paper. Examples of liner paper include paper made of kraft pulp and recycled paper.

[0027] 1.1.2.Processing solution The treatment liquid used in the recording method according to this embodiment is a water-based treatment liquid containing a coagulant and a silicone-based surfactant.

[0028] 1.1.2.(1) Flocculant The treatment liquid contains an aggregating agent that aggregates the components of the ink composition. The aggregating agent reacts with components such as the colorant contained in the ink and the resin particles that may be contained in the ink, thereby aggregating the colorant and resin particles. However, the degree of aggregation of the colorant and resin particles caused by the aggregating agent varies depending on the type of aggregating agent, colorant, and resin particles, and can be adjusted. Furthermore, the aggregating agent can aggregate the colorant and resin particles by reacting with them. Such aggregation can, for example, enhance the color development of the colorant, improve the fixation of the resin particles, and / or increase the viscosity of the ink.

[0029] The flocculant is not particularly limited, but examples thereof include metal salts, inorganic acids, organic acids, cationic compounds, etc., and examples of cationic compounds that can be used include cationic resins (cationic polymers), cationic surfactants, etc. Among these, metal salts include Polyvalent metal salts are preferred, and cationic resins are preferred as cationic compounds. Therefore, it is preferred that the flocculant be selected from cationic resins, organic acids, and polyvalent metal salts, as this will result in particularly excellent image quality, abrasion resistance, gloss, etc.

[0030] The metal salt is preferably a polyvalent metal salt, but metal salts other than polyvalent metal salts can also be used. Among these flocculants, it is preferable to use at least one selected from metal salts and organic acids because of their excellent reactivity with the components contained in the ink. Furthermore, among cationic compounds, it is preferable to use cationic resins because they are easily soluble in the treatment liquid. Furthermore, it is also possible to use multiple types of flocculants in combination.

[0031] Polyvalent metal salts are compounds composed of divalent or higher metal ions and anions. 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 ink components.

[0032] The anions constituting the polyvalent metal salt are inorganic or organic ions. That is, the polyvalent metal salt in the present invention is composed of an inorganic or organic ion and a polyvalent metal. Examples of such inorganic ions include chloride ions, bromide ions, iodide ions, nitrate ions, sulfate ions, and hydroxide ions. Examples of organic ions include organic acid ions, such as carboxylate ions.

[0033] 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.

[0034] 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, magnesium acetate, and aluminum acetate. These polyvalent metal salts may be used alone or in combination. Among these, calcium formate, magnesium sulfate, calcium nitrate, and / or calcium chloride are preferred because they can ensure sufficient solubility in water and reduce traces left by the treatment solution (making the traces less noticeable), with calcium formate and calcium nitrate being more preferred. These metal salts may contain water of hydration in their raw material form.

[0035] Examples of metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts, such as sodium sulfate and potassium sulfate.

[0036] 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, pyrrolidonecarboxylic acid, pyronecarboxylic acid, pyrrolecarboxylic acid, furancarboxylic acid, pyridinecarboxylic acid, coumaric acid, thiophenecarboxylic acid, nicotinic acid, or derivatives of these compounds, or salts thereof. One organic acid may be used alone, or two or more organic acids may be used in combination. Metal salts of organic acids are included in the above-mentioned metal salts.

[0037] 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.

[0038] Examples of cationic resins (cationic polymers) include cationic urethane resins, cationic olefin resins, cationic amine resins, etc. The cationic polymers are preferably water-soluble.

[0039] 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 (trade names, manufactured by Dainippon Ink and Chemicals, Inc.), Superflex 600, 610, 620, 630, 640, and 650 (trade names, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and Urethane Emulsion WBR-2120C and WBR-2122C (trade names, manufactured by Taisei Fine Chemical Co., Ltd.).

[0040] The cationic olefin resin has an olefin such as ethylene or propylene in its structural skeleton, and known resins can be appropriately selected and used. The cationic olefin resin may also be in an emulsion state dispersed in a solvent containing water or an organic solvent. Commercially available cationic olefin resins can be used, such as Arrowbase CB-1200 and CD-1200 (trade names, manufactured by Unitika Ltd.).

[0041] 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. Examples include polyamine resins, polyamide resins, and polyallylamine resins. 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.

[0042] Examples of cationic polyamine resins include Unisense KHE103L (hexamethylenediamine / epichlorohydrin resin, 1% aqueous solution with a pH of approximately 5.0, a 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 approximately 7.0, a 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, and 255LOX (manufactured by Arakawa Chemical Co., Ltd.), DK-6810, 6853, and 6885; WS-4010, 4011, 4020, 4024, 4027, and 4030 (manufactured by Seiko PMC Co., Ltd.), and Papiogen P-105 (manufactured by Senka Co., Ltd.). , Sumirez Resin 650 (30), 675A, 6615, SLX-1 (manufactured by Taoka Chemical Co., Ltd.), Catiomaster (registered trademark) PD-1, 7, 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.).

[0043] The polyamine resin also includes polyallylamine resin. Examples of the polyallylamine resin include polyallylamine hydrochloride, polyallylamine amidosulfate, 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 amidosulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate-sulfur dioxide copolymer, diallylmethylethyl Examples of the copolymers include ammonium ethyl sulfate-sulfur dioxide copolymer, methyldiallylamine hydrochloride-sulfur dioxide copolymer, diallyldimethylammonium chloride-sulfur dioxide copolymer, and diallyldimethylammonium chloride-acrylamide copolymer.

[0044] A plurality of types of these flocculants may be used. Furthermore, if at least one of polyvalent metal salts, organic acids, and cationic resins is selected from these flocculants, the flocculating action is more favorable, and therefore images of higher quality (especially with better color development) can be formed.

[0045] The total content of the aggregating agent in the treatment liquid is, for example, 0.1% by mass or more and 20% by mass or less, preferably 1% by mass or more and 20% by mass or less, and more preferably 2% by mass or more and 15% by mass or less, relative to the total mass of the treatment liquid. Even when the aggregating agent is used in both a solution and a dispersion, the solids content is preferably within the above range. A content of the aggregating agent of 1% by mass or more ensures that the aggregating agent has sufficient ability to aggregate the components contained in the ink. Furthermore, a content of the aggregating agent of 30% by mass or less improves the solubility and dispersibility of the aggregating agent in the treatment liquid, thereby improving the storage stability of the treatment liquid.

[0046] Even if the organic solvent contained in the treatment liquid is highly hydrophobic, 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 a flocculant with a solubility of 3 g or more and 80 g or less.

[0047] 1.1.2.(2) Water The treatment liquid used in the recording method according to this embodiment is an aqueous treatment liquid containing water. An aqueous treatment liquid is a composition containing water as one of the main solvent components. This allows for recording with less odor and a reduced environmental impact.

[0048] Water may be included as the main solvent component of the treatment liquid, and is a component that evaporates and dissipates upon drying. The water is preferably pure water or ultrapure water, such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water, from which ionic impurities have been removed as much as possible. Furthermore, using water sterilized by ultraviolet irradiation or the addition of hydrogen peroxide is preferable, as this can prevent the growth of mold and bacteria when the ink is stored for a long period of time. The water content is preferably 45% by mass or more of the total amount of the treatment liquid. The upper limit is, for example, 99% by mass or less. It is more preferably 50% by mass or more and 98% by mass or less, and even more preferably 55% by mass or more and 95% by mass or less.

[0049] 1.1.2.(3) Silicone surfactants The treatment liquid used in the recording method according to this embodiment contains a silicone surfactant. The silicone surfactant includes a silicone surfactant a, the surface tension of which in a 0.1% aqueous solution is 28.0 mN / m or less, and the surface tension of which in a 0.1% propylene glycol solution is 28.0 mN / m or less. "%" indicates mass %.

[0050] In this specification, the condition that the surface tension of a 0.1% aqueous solution of the surfactant is 28.0 mN / m or less and the surface tension of a 0.1% propylene glycol solution of the surfactant is 28.0 mN / m or less is sometimes referred to as "condition (a)." The surface tension in condition (a) is a value at 25°C. The surface tension may be measured in the same manner as the surface tension of the treatment liquid described below.

[0051] To find silicone surfactant a that satisfies condition (a), a 0.1% aqueous solution of silicone surfactant and a 0.1% propylene glycol solution are prepared, and the surface tension of these solutions is measured to determine whether or not they satisfy condition (a). Just do as you wish.

[0052] Examples of silicone surfactants a in which the surface tension of a 0.1% aqueous solution of the surfactant is 28.0 mN / m or less and the surface tension of a 0.1% propylene glycol solution of the surfactant is 28.0 mN / m or less include BYK-3420 and BYK-3480 (trade names, manufactured by BYK Japan).

[0053] In the early stages after the treatment liquid lands on the recording medium in the treatment liquid application process, the treatment liquid has not yet dried, and a large amount of water remains. On the other hand, in the later stages after the treatment liquid lands, the water in the treatment liquid has dried, and a large amount of organic solvent remains. This is because organic solvents with a normal boiling point higher than that of water are used to impart moisturizing properties to the treatment liquid. The wetting and spreading properties of ink droplets when ink comes into contact with the treatment liquid are thought to be related to the surface tension of the treatment liquid when it comes into contact with the ink.

[0054] It is believed that the surface tension of a 0.1% aqueous surfactant solution is related to the surface tension of the treatment liquid soon after it lands, and the surface tension of a 0.1% propylene glycol surfactant solution is related to the surface tension of the treatment liquid some time after it lands. Therefore, by including a silicone-based surfactant a that satisfies condition (a), the ink droplets that come into contact with the treatment liquid soon after it lands on the recording medium and the ink droplets that come into contact with the treatment liquid later after it lands will both have similar wetting and spreading characteristics, making it possible to achieve excellent graininess in the resulting image.

[0055] If the treatment liquid does not use a surfactant that satisfies condition (a), the ink droplets that come into contact with the treatment liquid early after landing will not have similar wetting and spreading properties, and the image will contain a mixture of ink droplets with large wetting and spreading properties and ink droplets with small wetting and spreading properties, which is thought to result in noticeable graininess.

[0056] It is presumed that silicone surfactant a that satisfies condition (a) has a good balance of hydrophilicity and hydrophobicity, and therefore has excellent surface activity in both aqueous solution and propylene glycol solution, thereby satisfying condition (a).

[0057] The content of silicone surfactant a in the treatment liquid is preferably 0.05% by mass to 2% by mass, more preferably 0.1% by mass to 1.5% by mass, and even more preferably 0.2% by mass to 1% by mass. Furthermore, 0.5% by mass to 0.8% by mass is more preferable. When the content of silicone surfactant a in the treatment liquid is within this range, the graininess and pinhole filling of the resulting image, as well as the abrasion resistance, can be further improved.

[0058] Silicone surfactant a may preferably be a silicone surfactant represented by the following formula (1). Such a silicone surfactant can easily satisfy condition a. Since the silicone surfactant represented by general formula (1) has a structure modified at both ends, the balance between hydrophilicity and hydrophobicity can be adjusted by adjusting the length of the main skeleton having the siloxane bond, excluding the polyether-modified group portion. This makes it easy to adjust the surfactant to satisfy condition a.

[0059] [ka]

[0060] (In the formula, a is an integer of 7 to 50, x and y are each independently an integer of 1 to 4, m and n are each independently an integer of 1 to 20, o and p are each independently an integer of 0 to 20, m+n is 2 to 40, o+p is 0 to 40, and R 1 and R 2 are each independently selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and a (meth)acrylic group. E is an ethylene group, and P is a propylene group. The order of the OE (EO) units and OP (PO) units is not particularly limited.

[0061] In equation (1); a is an integer of 7 to 50, preferably 8 to 48, more preferably 9 to 45, even more preferably 10 to 40, still more preferably 11 to 30, and particularly preferably 11 to 20. x and y each independently represent an integer of 1 to 4, preferably 1 to 3, and more preferably 2 or 3. m and n each independently represent an integer of 1 to 20, preferably 2 to 15, more preferably 4 to 10, and even more preferably 5 to 8. o and p each independently represent an integer of 0 to 20, preferably 0 to 10, more preferably 0 to 5, even more preferably 0 to 3, particularly preferably 0 to 1, and most particularly preferably 0. m+n is 2-40, preferably 4-30, more preferably 8-20, and even more preferably 10-15. o+p is 0 to 40, preferably 0 to 20, more preferably 0 to 10, even more preferably 0 to 3, particularly preferably 0 to 1, and even more particularly preferably 0. R 1 and R 2 are each independently selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and a (meth)acrylic group, and are preferably a hydroxy group. The order of the OE(EO) units and OP(PO) units is not important; in other words, when there are one or more OE(EO) units and one or more OP(PO) units, the order of one OE(EO) unit and one P(PO) unit does not matter. P is a propylene group, and examples thereof include a 1,2-propylene group and a 1,3-propylene group, with a 1,2-propylene group being preferred.

[0062] The silicone surfactant a may be, and is preferably, a silicone surfactant represented by the following formula (2):

[0063] [ka]

[0064] (In the formula, R 3 each independently represents an alkyl group having 1 to 6 carbon atoms, and R 4 represents an alkylene group having 1 to 4 carbon atoms, and R 5 represents a group selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and a (meth)acrylic group; EO represents an ethylene oxide group; PO represents a propylene oxide group; the order between the EO units and the PO units is arbitrary; d and e are integers of 1 or more; d+e represents an integer of 2 to 10; f is an integer of 1 to 20; and g is an integer of 0 to 20.

[0065] In equation (2); d+e is an integer of 2 to 10, preferably 3 to 8, and more preferably 3 to 6. It is preferable that d and e are each half of d+e. R 4 is an alkylene group having 1 to 4 carbon atoms, preferably 1 to 3, and more preferably 2 or 3. f is an integer of 1 to 20, preferably 2 to 15, more preferably 4 to 10, and even more preferably 5 to 8. g is an integer of 0 to 20, preferably 0 to 10, more preferably 0 to 5, even more preferably 0 to 3, particularly preferably 0 to 1, and even more particularly preferably 0. R 5 is selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and a (meth)acrylic group, and is preferably a hydroxy group.

[0066] Silicone surfactant a may be obtained by synthesis. For example, it can be synthesized by an addition reaction between a silicone oil having an Si-H structure and a polyether having a carbon-carbon double bond at its terminal. It may be synthesized by an addition reaction using a Pt-based catalyst or the like. Silicone oil having an Si-H structure may be a compound of formula (1) or formula (2) in which the polyether modifying group of the Si atom to which the polyether modifying group is bonded is substituted with a hydrogen atom, and polyether having a carbon-carbon double bond at its terminal may be a compound of formula (1) or formula (2) in which the Si atom of the carbon atom bonded to the Si atom of the polyether modifying group is substituted with a carbon-carbon double bond.

[0067] Furthermore, in the molecular weight distribution measured by gel permeation chromatography (GPC), the silicone surfactant a preferably has a maximum peak in the molecular weight range of 300 or more in the molecular weight range of 1000 to 4500. When the molecular weight of the silicone surfactant a is in this range, the rub resistance of the resulting image can be further improved.

[0068] Furthermore, when the silicone surfactant has a molecular weight within the above range, it is easy to obtain a surfactant that satisfies the above condition (a), which is preferable. For example, the size of the surfactant molecule is also related to the ease of association and arrangement of the surfactant molecules in a solution, and when the silicone surfactant has a molecular weight within the above range, the surfactant can easily form an association or arrangement at the boundary between the aqueous solution and the propylene glycol solution. It is speculated that the surfactant molecules will be more likely to associate and align, making it easier to satisfy condition (a). However, this is only a speculation, and the reason is not limited to this.

[0069] In the molecular weight distribution measured by gel permeation chromatography, the maximum peak in the range of molecular weights of 300 or more is more preferably in the range of 1500 to 4000, even more preferably in the range of 1550 to 3000, and even more preferably in the range of 1600 to 2500.

[0070] The maximum peak of a silicone surfactant in the molecular weight range of 300 or more can be identified from a GPC molecular weight distribution chart obtained by plotting the logarithm of molecular weight M (LogM) on the horizontal axis and the differential value of concentration fraction (dw / d(LogM)) on the vertical axis. Here, "maximum peak" refers to the largest peak (mountain) in the molecular weight range of 300 or more. Furthermore, "maximum peak in the molecular weight range of 300 or more" means that peaks below 300 are ignored. In other words, although there may be a maximum peak below 300, it is the maximum peak when viewed only in the molecular weight range of 300 or more.

[0071] Although not particularly limited, for example, the measurement conditions for GPC measurement in this embodiment can be the conditions described in the Examples, and the molecular weight can be determined using standard polystyrene.

[0072] The treatment liquid may further contain a silicone surfactant other than the silicone surfactant a, that is, a silicone surfactant that does not satisfy the condition (a). Examples of such silicone surfactants include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348, and BYK-349 (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, and KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), and Silface SAG002, 005, 503A, and 008 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.).

[0073] When the treatment liquid contains a silicone surfactant that does not satisfy condition (a), it is preferable that the content be such that it does not inhibit the action of the silicone surfactant that satisfies the above condition (a).

[0074] 1.1.2.(4) Other ingredients The treatment liquid may contain components such as resin particles, organic solvents, surfactants, waxes, additives, preservatives, antifungal agents, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, and antifungal agents, as long as they do not impair the function. These will be explained in order below.

[0075] (resin particles) The treatment liquid may contain resin particles. Resin particles may further improve the adhesion of an image formed by the ink adhered to a recording medium. Examples of resin particles include urethane-based resins, acrylic-based resins (including styrene-acrylic-based resins), fluorene-based resins, polyolefin-based resins, rosin-modified resins, terpene-based resins, polyester-based resins, polyamide-based resins, epoxy-based resins, vinyl chloride-based resins, vinyl chloride-vinyl acetate copolymers, and ethylene vinyl acetate-based resins. Among these, urethane-based resins, acrylic-based resins, polyolefin-based resins, and polyester-based resins are preferred. These resin particles are often handled in the form of an emulsion, but may also be in the form of a powder. Furthermore, the resin particles may be used alone or in combination of two or more types. The glass transition temperature (Tg) of the resin particles is preferably -50°C or higher and 200°C or lower, more preferably 0°C or higher and 150°C or lower, and even more preferably 50°C or higher and 100°C or lower. 50°C or higher and 80°C or lower is particularly preferred. When the glass transition temperature (Tg) of the resin particles is within the above range, the durability and clogging resistance tend to be superior. The glass transition temperature is measured, for example, using a differential scanning calorimeter "DSC7000" manufactured by Hitachi High-Tech Science Corporation in accordance with JIS K7121 (Method for measuring transition temperature of plastics).

[0076] The volume average particle diameter of the resin particles is preferably 10 nm or more and 300 nm or less, more preferably 30 nm or more and 300 nm or less, even more preferably 30 nm or more and 250 nm or less, and particularly preferably 40 nm or more and 220 nm or less. The volume average particle diameter can be measured by the method described above.

[0077] The resin of the resin particles preferably has an acid value of 50 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 20 mgKOH / g or less, and particularly preferably 10 mgKOH / g or less. The lower limit of the acid value is 0 mgKOH / g or more, preferably 5 mgKOH / g or more, and more preferably 10 mgKOH / g or more. In this case, image quality is excellent and is preferable. The acid value can be measured by the above-mentioned method.

[0078] When resin particles are contained in the treatment liquid, the content is, in terms of solids, 0.1% by mass or more and 20% by mass or less, preferably 1% by mass or more and 15% by mass or less, and more preferably 2% by mass or more and 10% by mass or less, relative to the total mass of the treatment liquid.

[0079] (organic solvent) The treatment liquid used in the recording method according to this embodiment may contain an organic solvent. The organic solvent is preferably water-soluble. One of the functions of the organic solvent is to improve the wettability of the treatment liquid with respect to the recording medium and to increase the moisturizing properties of the treatment liquid. The organic solvent can also function as a moisturizer and a penetrant.

[0080] Examples of organic solvents include esters, alkylene glycol ethers, cyclic esters, nitrogen-containing solvents, polyhydric alcohols, etc. Examples of nitrogen-containing solvents include cyclic amides and non-cyclic amides, etc. Examples of non-cyclic amides include alkoxyalkylamides.

[0081] Examples of the esters include glycol monoacetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate, and glycol diesters such as ethylene glycol diacetate, diethylene glycol diacetate, and propylene glycol diacetate.

[0082] The alkylene glycol ether may be a monoether or diether of alkylene glycol, and is preferably an alkyl ether. Specific examples include alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, and diethylene glycol monomethyl ether, and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether.

[0083] Examples of cyclic esters include cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, and β-butyrolactone, as well as compounds in which the hydrogen atom of the methylene group adjacent to the carbonyl group of these cyclic esters is substituted with an alkyl group having 1 to 4 carbon atoms.

[0084] Examples of alkoxyalkylamides include 3-methoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, 3-methoxy-N,N-methylethylpropionamide, 3-ethoxy-N,N-dimethylpropionamide, 3-ethoxy-N,N-diethylpropionamide, 3-ethoxy-N,N-methylethylpropionamide, 3-n-butoxy-N,N-dimethylpropionamide, 3-n-butoxy-N,N-diethylpropionamide, and 3-n-butoxy-N,N-methylethylpropionamide.

[0085] Examples of cyclic amides include lactams, such as pyrrolidones such as 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone. These are preferred in terms of solubility of the flocculant and promotion of film formation of resin particles, which will be described later, and 2-pyrrolidone is particularly preferred.

[0086] It is also preferable to use a compound represented by the following general formula (1) as the alkoxyalkylamide.

[0087] R 1 -O-CH2CH2-(C=O)-NR 2 R 3 ···(1)

[0088] In the above formula (1), R 1 represents an alkyl group having 1 to 4 carbon atoms, and R 2 and R 3 each independently represents a methyl group or an ethyl group. The "alkyl group having 1 to 4 carbon atoms" can be a linear or branched alkyl group, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, or a tert-butyl group. The compound represented by the above formula (1) may be used alone or in combination of two or more types.

[0089] The function of the nitrogen-containing solvent is, for example, to improve the surface drying and fixability of the treatment liquid applied to a low-absorbency recording medium. In particular, the compound represented by the above formula (1) is excellent in the ability to moderately soften and dissolve vinyl chloride resins. Therefore, the compound represented by the above formula (1) softens and dissolves the recording surface containing vinyl chloride resin, allowing the treatment liquid to penetrate into the interior of the low-absorbency recording medium. By the treatment liquid penetrating into the low-absorbency recording medium in this way, the treatment liquid is firmly fixed and the surface of the treatment liquid is easily dried. Therefore, the resulting image is likely to have excellent surface drying and fixability.

[0090] When a nitrogen-containing solvent is used in the treatment liquid, its content, relative to the total mass of the treatment liquid, preferably does not exceed 15 mass%, more preferably does not exceed 10 mass%, even more preferably does not exceed 5 mass%, further preferably does not exceed 2 mass%, and more preferably does not exceed 1 mass%. In particular, it is preferable that the processing liquid does not contain the above-mentioned amide solvents, which can further improve the graininess and abrasion resistance of the resulting image.

[0091] Examples of polyhydric alcohols include 1,2-alkanediols (e.g., alkanediols such as ethylene glycol, propylene glycol (also known as propane-1,2-diol), 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol), and 1,2-alkanediols other than 1,2-alkanediols. Examples of suitable polyols include polyhydric alcohols (polyols) (for example, diethylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol (also known as 1,3-butylene glycol), 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, trimethylolpropane, and glycerin).

[0092] Examples of polyhydric alcohols include alkanediols and polyols. The alkanediols are preferably alkanediols having 5 or more carbon atoms. The number of carbon atoms in the alkane is preferably 5 to 10, more preferably 5 to 8, and even more preferably 5 to 6. 1,2-alkanediol, propylene glycol, etc. are preferred. 1,2-alkanediol is preferred.

[0093] Examples of polyols include alkanediols having 4 or less carbon atoms, intermolecular condensation products of hydroxyl groups of alkanediols, and alkanepolyols of triol or higher. The number of carbon atoms in the above alkanes is preferably 2 to 3. The number of hydroxyl groups in the polyol molecule is 2 or more, preferably 5 or less, more preferably 3 or less. When the polyol is an intermolecular condensation product as described above, the number of intermolecular condensations is 2 or more, preferably 4 or less, more preferably 3 or less. The polyhydric alcohols can be used alone or in combination of two or more.

[0094] Alkanediols and polyols can function primarily as penetrating solvents and / or moisturizing solvents, but alkanediols tend to have stronger penetrating solvent properties, while polyols tend to have stronger moisturizing solvent properties.

[0095] The treatment liquid more preferably contains an organic solvent that is a polyol having a normal boiling point of 170°C or higher and 240°C or lower. This can further improve the graininess and abrasion resistance of the resulting image. The treatment liquid may also preferably contain an organic solvent that is a polyhydric alcohol having a normal boiling point of 170°C or higher and 240°C or lower.

[0096] When the treatment liquid contains an organic solvent, the organic solvent may be used alone or in combination of two or more. The total content of the organic solvent relative to the total mass of the treatment liquid is, for example, 5% by mass to 50% by mass, preferably 10% by mass to 45% by mass, more preferably 15% by mass to 40% by mass, and even more preferably 20% by mass to 40% by mass. Furthermore, 25 to 35% by mass is preferred. By having the organic solvent content within the above range, the balance between wetting and spreading properties and drying properties is further improved, making it easier to form higher-quality images.

[0097] It is also good and preferable that the content of the organic solvent, which is a polyol having a normal boiling point of 170° C. or more and 240° C. or less, falls within the above range. It is also good and preferable that the content of the organic solvent, which is a polyhydric alcohol having a normal boiling point of 170° C. or more and 240° C. or less, falls within the above range.

[0098] The treatment liquid preferably contains no more than 1% by mass, and more preferably no more than 0.5% by mass, of polyhydric alcohols having a normal boiling point above 280° C. It is also possible and preferred to set the content of organic solvents, including but not limited to polyhydric alcohols having a normal boiling point above 280° C., within the above range.

[0099] (surfactant) The treatment liquid may contain a surfactant other than a silicone surfactant. The surfactant has a function of adjusting the surface tension of the treatment liquid and, for example, adjusting the wettability with respect to the recording medium. Among surfactants, for example, acetylene glycol surfactants and fluorine-based surfactants can be preferably used.

[0100] When a surfactant other than the silicone surfactant a is contained, it is preferable that the content be such that it does not inhibit the action of the silicone surfactant that satisfies the above condition (a).

[0101] 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 Co.). , Olfine 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.).

[0102] As the fluorine-based surfactant, 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).

[0103] (wax) The treatment liquid may contain wax. Wax has the function of providing lubricity to ink images, which may reduce peeling of the images.

[0104] Examples of wax components include plant and animal waxes such as carnauba wax, candelilla wax, beeswax, rice wax, and lanolin; petroleum waxes such as paraffin wax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, and petrolatum; mineral waxes such as montan wax and ozokerite; synthetic waxes such as carbon wax, Hoechst wax, polyolefin wax, and stearic acid amide; and natural and synthetic wax emulsions and blended waxes such as α-olefin-maleic anhydride copolymers, which can be used alone or in combination. Among these, polyolefin waxes (particularly polyethylene wax and polypropylene wax) and paraffin wax are preferred from the viewpoint of their superior effect of improving adhesion to flexible packaging films, as described below.

[0105] As the wax, commercially available products can be used as they are, such as Nopcoat PEM-17 (trade name, manufactured by San Nopco Ltd.), Chemipearl W4005 (trade name, manufactured by Mitsui Chemicals, Inc.), and AQUACER 515, 539, and 593 (all trade names, manufactured by BYK Japan K.K.).

[0106] Furthermore, in cases where the recording method includes a heating step or the like, in order to prevent the wax from melting too much and its performance from being reduced, it is preferable to use a wax having a melting point of preferably 50°C or higher and 200°C or lower, more preferably 70°C or higher and 180°C or lower, and even more preferably 90°C or higher and 150°C or lower.

[0107] The wax may be supplied in the form of an emulsion or suspension. The wax content is, in terms of solid content, 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, and even more preferably 0.5% by mass to 2% by mass, relative to the total mass of the treatment liquid. When the wax content is within the above range, the wax functions well. Furthermore, if the treatment liquid and at least one of the clear ink composition, the first ink composition, and the second ink composition described below contain wax, the function of imparting lubricity to an image can be more fully obtained.

[0108] (additives) The treatment liquid may contain additives such as ureas, amines, sugars, etc. Examples of ureas include urea, ethylene urea, tetramethyl urea, thiourea, 1,3-dimethyl-2-imidazolidinone, etc., and betaines (trimethylglycine, triethylglycine, tripropylglycine, triisopropylglycine, N,N,N-trimethylalanine, N,N,N-triethylalanine, N,N,N-triisopropylalanine, N,N,N-trimethylmethylalanine, carnitine, acetylcarnitine, etc.).

[0109] Examples of amines include diethanolamine, triethanolamine, triisopropanolamine, etc. Ureas and amines may function as pH adjusters. Examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0110] (others) The processing liquid used in the recording method according to this embodiment may further contain components such as preservatives, antifungal agents, rust inhibitors, chelating agents, viscosity adjusters, antioxidants, and antifungal agents, as required.

[0111] 1.1.2.(5) Physical properties of processing liquid From the viewpoint of ensuring appropriate wetting and spreading properties on the recording medium, the treatment liquid used in the recording method of this embodiment preferably has a surface tension of 40 mN / m or less, preferably 38 mN / m or less, more preferably 35 mN / m or less, and even more preferably 30 mN / m or less at 25° C. The surface tension can be measured by checking the surface tension when a platinum plate is wetted with the composition in an environment of 25° C. using an automatic surface tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

[0112] The treatment liquid is more preferably applied to the recording medium by an inkjet method. In this case, the viscosity at 20°C is preferably 1.5 mPa·s or more and 15 mPa·s or less, more preferably 1.5 mPa·s or more and 7 mPa·s or less, and even more preferably 1.5 mPa·s or more and 5.5 mPa·s or less. When the treatment liquid is applied to the recording medium by an inkjet method, it is easy to efficiently form a predetermined treatment liquid application area on the recording medium.

[0113] 1.1.3. Method of applying processing liquid to recording medium The treatment liquid application process is performed by ejecting the treatment liquid from the inkjet head and applying it to the recording medium, and any method may be used as long as the treatment liquid is applied while scanning, which is a relative positional movement between the inkjet head and the recording medium. Examples of inkjet methods include a serial method and a line method. This allows for efficient printing of a variety of small quantities using a small device.

[0114] The amount of treatment liquid applied in the treatment liquid application process is 0.4 mg / inch 2 The above is preferable. Furthermore, 0.5 mg / inch 2 More than 1.0 mg / inch is preferable. 2 It is preferable that the concentration is 1.5 mg / inch or more. 2 More preferably, it is 2.0 mg / inch or more. 2The above is even more preferable. In this way, an image with even better filling properties can be obtained.

[0115] The upper limit of the amount of treatment liquid to be applied in the treatment liquid application step is 5.0 mg / inch. 2 or less, and even 3.0 mg / inch 2 Below, 2.5mg / inch 2 If the amount is less than this, the image will be prone to graininess, but even in this case, the effect of the recording method of this embodiment, that is, the ability to suppress graininess, will be more pronounced.It is also good and preferable to set the maximum amount of treatment liquid applied in the treatment liquid application step to within the above range.

[0116] Furthermore, the mass (ng) of the droplets of the treatment liquid in the treatment liquid application step is preferably 0.5 ng to 10 ng, more preferably 1 ng to 7 ng, even more preferably 1 ng to 5 ng, and even more preferably 2 ng to 4 ng. In terms of dot size (ng / dot), the mass (ng) of the droplets of the treatment liquid in the treatment liquid application step is preferably 0.5 ng / dot to 10 ng / dot, more preferably 1 ng / dot to 7 ng / dot, even more preferably 1 ng / dot to 5 ng / dot, and even more preferably 2 ng / dot to 4 ng / dot.

[0117] After the treatment liquid is applied to the recording medium in the treatment liquid application step, ink is applied to the recording medium in each ink application step. Furthermore, the treatment liquid application step applies the treatment liquid to the same scanning area in the same scan (pass) as the scan in which the first ink composition and / or the second ink composition is applied to the recording medium. This also includes an embodiment in which the treatment liquid, the first ink composition, and the second ink composition are applied to the recording medium in "one pass" in the recording apparatus described below.

[0118] The treatment liquid application step is carried out so that each ink composition applied to the recording medium in each ink application step and the treatment liquid applied to the recording medium in the treatment liquid application step can come into contact with each other on the recording medium and react with each other.

[0119] 1.2. First ink application process The first ink application step is a step of applying the first ink composition, which is a water-based ink composition containing a coloring material, to a recording medium. The method of application to a recording medium will be described later.

[0120] 1.2.1. First ink composition The first ink composition is a water-based ink composition that contains a coloring material.

[0121] 1.2.1.(1) Colorants The first ink composition is an ink containing a colorant. Examples of the colorant include dyes and pigments. The colorant can be, for example, a colored colorant such as cyan, yellow, magenta, or black, or a white colorant. Other examples include special color inks such as red, orange, blue, or green, and light color inks such as light magenta, light cyan, or gray.

[0122] The colorant may be either a dye or a pigment, or a mixture thereof. However, of dyes and pigments, it is more preferable to use a pigment. The pigment has excellent storage stability such as light resistance, weather resistance, and gas resistance, and from this viewpoint, it is preferable that the pigment is an organic pigment.

[0123] Specifically, the pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, quinone pigments, and the like. Polycyclic pigments such as phthalon pigments, dye chelates, dye lakes, nitro pigments, nitroso pigments, aniline black, daylight fluorescent pigments, carbon black, etc. can be used. The above pigments can be used alone or in combination of two or more. Furthermore, brilliant pigments can be used as colorants.

[0124] Specific examples of pigments include, but are not limited to, the following:

[0125] Examples of black pigments include No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, and No. 2200B (all manufactured by Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, and Raven 700 (all manufactured by Carbon Columbia), Rega1 400R, Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, and Monarch 1400 (manufactured by CABOT JAPAN). KK)), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color B1ack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, and Special Black 4 (all manufactured by Degussa).

[0126] Examples of yellow pigments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, and 180.

[0127] Examples of magenta pigments include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48(Ca), 48(Mn), 57(Ca), 57:1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, and 245, and CI Pigment Violet. Examples include 19, 23, 32, 33, 36, 38, 43, and 50.

[0128] Examples of cyan pigments include CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, and 66, and CI Vat Blue 4 and 60.

[0129] Furthermore, pigments other than magenta, cyan, and yellow are not particularly limited, but examples thereof include CI Pigment Green 7, 10, CI Pigment Brown 3, 5, 25, 26, and CI Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, and 63.

[0130] The pearl pigment is not particularly limited, but examples thereof include pigments having pearlescent or interference luster, such as titanium dioxide-coated mica, fish scale foil, and bismuth oxychloride.

[0131] The metallic pigment is not particularly limited, but examples thereof include particles of aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, copper, and the like, either alone or as an alloy.

[0132] Examples of white coloring materials include metal oxides, barium sulfate, calcium carbonate, and other metal compounds. Examples of metal oxides include titanium dioxide, zinc oxide, silica, alumina, and magnesium oxide. Furthermore, particles having a hollow structure may be used as the white coloring material, and known particles having a hollow structure may be used. Among the examples listed above, titanium dioxide is preferably used as the white coloring material from the viewpoint of good whiteness and abrasion resistance.

[0133] As the dye, various dyes that are usually used in inkjet recording, such as direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes, can be used.

[0134] The colorant is preferably one that can be stably dispersed or dissolved in the dispersion medium, and may be dispersed using a dispersant as needed.

[0135] It is preferable that the colorant be stably dispersed in the dispersion medium, and therefore a dispersant may be used for dispersion. Examples of dispersants include resin dispersants, and are selected from those that can improve the dispersion stability of the colorant in the first ink composition. Furthermore, the colorant may be used as a self-dispersing pigment by modifying the surface of the pigment particles by oxidizing or sulfonating the pigment surface with, for example, ozone, hypochlorous acid, fuming sulfuric acid, or the like.

[0136] Examples of resin dispersants (dispersant resins) include (meth)acrylic resins and salts thereof such as poly(meth)acrylic acid, (meth)acrylic acid-acrylonitrile copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, and vinylnaphthalene-(meth)acrylic acid copolymer; styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid copolymer. Examples of suitable water-soluble resins include styrene-based resins such as acrylic acid-(meth)acrylic acid ester copolymers, styrene-maleic acid copolymers, and styrene-maleic anhydride copolymers, and salts thereof; urethane-based resins and salts thereof, which are polymeric compounds (resins) containing urethane bonds formed by the reaction of an isocyanate group with a hydroxyl group and may be linear and / or branched, and may have a crosslinked structure; polyvinyl alcohols; vinyl naphthalene-maleic acid copolymers and salts thereof; vinyl acetate-maleic acid ester copolymers and salts thereof; and vinyl acetate-crotonic acid copolymers and salts thereof. Among these, preferred are copolymers of a monomer having a hydrophobic functional group and a monomer having a hydrophilic functional group, and polymers composed of a monomer having both a hydrophobic and a hydrophilic functional group. The copolymers may be random copolymers, block copolymers, alternating copolymers, or graft copolymers. Among styrene-based resins, copolymers with (meth)acrylic monomers are also considered (meth)acrylic resins.

[0137] Commercially available styrene resin dispersants include, for example, X-200, X-1, X-205, X-220, and X-228 (manufactured by Seiko PMC Corporation), Nopcosperse (registered trademark) 6100 and 6110 (manufactured by San Nopco Ltd.), Joncryl 67, 586, 611, 678, 680, 682, and 819 (manufactured by BASF), and DISPERBYK-190 (manufactured by BYK-Chemie Japan Co., Ltd.). Examples of such anti-inflammatory agents include N-EA137, N-EA157, N-EA167, N-EA177, N-EA197D, N-EA207D, and E-EN10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0138] Commercially available acrylic resin dispersants include BYK-187, BYK-190, BYK-191, BYK-194N, and BYK-199 (manufactured by BYK-Chemie Co., Ltd.), Aron A-210, A6114, AS-1100, AS-1800, A-30SL, A-7250, and CL-2 (manufactured by Toagosei Co., Ltd.).

[0139] Furthermore, commercially available urethane resin dispersants include BYK-182, BYK-183, BYK-184, and BYK-185 (manufactured by BYK-Chemie Co., Ltd.), TEGO Disperse 710 (manufactured by Evonic Tego Chemi), and Borchi (registered trademark) Gen 1350 (manufactured by OMG Borschers).

[0140] The dispersants may be used alone or in combination of two or more. The total content of the dispersants is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 25 parts by mass, even more preferably 1 to 20 parts by mass, and even more preferably 1.5 to 15 parts by mass, relative to 50 parts by mass of the white colorant. By using a dispersant content of 0.1 parts by mass or more relative to 50 parts by mass of the colorant, the dispersion stability of the colorant can be further improved. Furthermore, by using a dispersant content of 30 parts by mass or less relative to 50 parts by mass of the colorant, the viscosity of the resulting dispersion can be kept low.

[0141] Among the dispersants listed above, at least one selected from anionic dispersant resins is more preferred. In this case, the weight-average molecular weight of the dispersant is more preferably 500 or more. Furthermore, it is more preferably 5,000 or more and 100,000 or less, and even more preferably 10,000 or more and 50,000 or less.

[0142] The use of such a resin dispersant as a dispersant improves the dispersion and aggregation of the pigment, resulting in better dispersion stability and images of better image quality. Furthermore, the viscosity increase rate of the first ink composition, which will be described later, can be easily increased by 5 times or more, which is preferable.

[0143] Anionic dispersant resins are resins that have anionic functional groups and exhibit anionic properties. Examples of the anionic functional groups include carboxyl groups, sulfo groups, and phosphate groups. Among these groups, carboxyl groups are more preferred.

[0144] The dispersant resin preferably has an acid value, preferably 5 mgKOH / g or more, more preferably 10 to 200 mgKOH / g, and even more preferably 15 to 150 mgKOH / g. An acid value of 20 to 100 mgKOH / g is more preferred, and 30 to 80 mgKOH / g is even more preferred. Furthermore, the lower limit is preferably 40 mgKOH / g or more, more preferably 50 mgKOH / g or more, particularly preferably 60 mgKOH / g or more, and even more preferably 70 mgKOH / g or more. In this case, the viscosity increase rate of the first ink composition (described later) can be easily increased by 5 times or more, which is preferred.

[0145] The acid value can be measured by neutralization potentiometric titration in accordance with JIS K 0070. As a titration device, for example, "AT610" manufactured by Kyoto Electronics Manufacturing Co., Ltd. can be used.

[0146] The content of the colorant relative to the total mass of the first ink composition is preferably 0.3% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, even more preferably 1% by mass to 10% by mass, and even more preferably 2% by mass to 7% by mass.

[0147] When a pigment is used as the colorant, the volume average particle diameter of the pigment particles is preferably 10 nm to 300 nm, more preferably 30 nm to 250 nm, even more preferably 50 nm to 250 nm, and particularly preferably 70 nm to 200 nm. Furthermore, 80 nm to 150 nm is preferable. The volume average particle diameter of the colorant is measured in the initial state using the aforementioned method for determining the volume average particle diameter. A volume average particle diameter within the above range is preferable in that the desired colorant is easily available and the properties of the colorant can be easily improved.

[0148] 1.2.1.(2) Water The first ink composition used in the recording method according to this embodiment is an aqueous ink containing water. An aqueous ink is a composition containing water as one of its main solvent components. This allows for recording with less odor and a reduced environmental impact. The water content may be the same as that of the treatment liquid described above, and therefore further explanation will be omitted.

[0149] 1.2.1.(3) Other ingredients In addition to the colorant and water, the first ink composition may contain components such as resin particles, organic solvents, surfactants, waxes, additives, preservatives, antifungal agents, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, and antifungal agents.

[0150] The components of the first ink composition, other than the colorant and the aggregating agent, are the same as those that may be used in the treatment liquid, and can be selected independently of the treatment liquid. These components may all be the same as those in the treatment liquid described above, and detailed explanations will be omitted by replacing "treatment liquid" with "first ink composition."

[0151] When a surfactant is added to the first ink composition, the same surfactant as that used in the treatment liquid described above can be used, and can be selected regardless of whether condition (a) is satisfied or not.

[0152] 1.2.1.(4) Physical properties of the first ink composition To ensure appropriate wetting and spreading properties on a recording medium, the first ink composition used in the recording method of this embodiment preferably has a surface tension of 40 mN / m or less, preferably 38 mN / m or less, more preferably 35 mN / m or less, and even more preferably 30 mN / m or less at 25° C. The surface tension can be measured by wetting a platinum plate with the composition at 25° C. using an automatic surface tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

[0153] The first ink composition is applied to a recording medium by an inkjet method, and therefore the viscosity at 20°C is preferably 1.5 mPa·s or more and 15 mPa·s or less, more preferably 1.5 mPa·s or more and 7 mPa·s or less, and even more preferably 1.5 mPa·s or more and 5.5 mPa·s or less.

[0154] 1.2.2. Viscosity increase rate of first ink composition The first ink composition preferably exhibits a viscosity increase of at least five times when mixed with a 7% by mass aqueous solution of calcium formate at a mass ratio (first ink composition:7% by mass aqueous solution of calcium formate) of 10:1. By having such a viscosity increase, the components of the first ink composition can be sufficiently cohesive when contacted with the treatment liquid, and the quality of the image formed with the first ink composition can be further improved. This further improves the unevenness of the shading of the resulting image.

[0155] Regarding the viscosity increase rate of the first ink composition, the "viscosity increase rate" is defined as follows in relation to the increase in the viscosity of the ink when mixed with a 7% by mass aqueous solution of calcium formate. That is, the viscosity increase rate is the increase in the viscosity of the ink when the ink and treatment liquid used in the recording method are mixed at a mass ratio of ink:treatment liquid of 10:1. The inks are mixed and stirred together, and the viscosity ratio (multiplication factor) of the mixed liquid after mixing to the viscosity of the ink before mixing is determined. Viscosity is measured at 20°C. Therefore, the viscosity increase ratio is the multiplication factor of the viscosity after mixing based on the viscosity before mixing. The viscosity increase ratio is, for example, approximately 0.5 to 10.0 times. Note that depending on the ink composition, the viscosity increase ratio may be less than 1.0 times, resulting in a decrease in viscosity, but this is still referred to as the viscosity increase ratio. Viscosity can be measured using a rheometer.

[0156] The lower limit of the viscosity increase rate of the first ink composition is preferably 2 times or more, more preferably 3 times or more, and even more preferably 5 times or more, more preferably more than 5 times, more preferably 5.5 times or more, even more preferably 6 times or more, particularly preferably 7 times or more, and even more preferably 10 times or more.

[0157] On the other hand, the upper limit of the viscosity increase rate of the first ink composition is not limited, but is preferably 20 times or less, more preferably 10 times or less, more preferably 9 times or less, even more preferably 8.5 times or less, and even more preferably 8 times or less. When the viscosity increase rate of the first ink composition is within the above range, image quality, crack resistance, abrasion resistance, ejection stability, and the like are more excellent, which is preferable. Furthermore, the image quality of the resulting image is also excellent, and graininess in particular can be reduced.

[0158] The viscosity increase rate of the first ink composition can be adjusted mainly by adjusting the type and content of the pigment (including the resin dispersant) and resin particles. In particular, adjusting the type and content of the pigment (including the resin dispersant) is preferable because it is easy to adjust.

[0159] 1.2.3. Method for applying the first ink composition to a recording medium The first ink deposition step may be performed by any method as long as the first ink composition is deposited while scanning, moving the relative positions of the inkjet head and the recording medium. Examples of inkjet methods include a serial method and a line method. This method allows for efficient printing of a variety of small quantities using a small device.

[0160] The maximum amount of the first ink composition applied in the first ink application step was 1.5 mg / inch. 2 More preferably, it is 3.0 mg / inch or more. 2 More than 4.0 mg / inch is preferable. 2 It is preferable that the concentration is 11.0 mg / inch or more. 2 More preferably, it is 10.0 mg / inch or less. 2 More preferably, it is 9.0 mg / inch or less. 2 More preferably, it is 7.0 mg / inch or less. 2 The following is even more preferable: In this way, an image with even better filling properties can be obtained.

[0161] Furthermore, the mass (ng) of the droplets of the first ink composition in the first ink applying step is preferably 8 ng or less, more preferably 1 ng to 8 ng, even more preferably 1 ng to 7 ng, and even more preferably 2 ng to 6 ng. In terms of dot size (ng / dot), the mass (ng) of the droplets of the first ink composition in the first ink applying step is preferably 8 ng / dot or less, more preferably 1 ng to 8 ng / dot, even more preferably 1 ng to 7 ng / dot, and even more preferably 2 ng / dot to 6 ng / dot.

[0162] In the first ink application step, ink is applied to the recording medium after the treatment liquid is applied to the recording medium in the treatment liquid application step. In addition, in the first ink application step, the first ink composition is applied to the same scanning area in the same scan (pass) as the scan in which the treatment liquid is applied to the recording medium.

[0163] 1.3. Second ink application process The first ink application step is a step of applying the second ink composition, which is a water-based ink composition containing a coloring material, to a recording medium.

[0164] 1.3.1. Second ink composition The second ink composition is a water-based ink composition that contains a coloring material.

[0165] The second ink composition used in the recording method according to this embodiment is an aqueous ink containing water, and is similar to the first ink composition described above, so in the following description, the "first ink composition" will be read as the "second ink composition." The physical properties, viscosity increase rate, and method of applying the second ink composition to a recording medium are also similar to those of the first ink composition, so in the following description, the "first ink composition" will be read as the "second ink composition."

[0166] The second ink composition preferably contains a colorant different in color from the colorant contained in the first ink composition and is an ink different in color from the first ink composition. In this case, multicolor printing can be performed, which is a useful recording method, and the present embodiment is preferable because it can obtain excellent image quality with reduced graininess and the like.

[0167] 1.4. Time interval and sequence of each attachment step In the recording method of this embodiment, in a scan that moves the relative positions of the inkjet head and the recording medium, the treatment liquid, the first ink composition, and the second ink composition are deposited on the recording medium in the same scan area.

[0168] In the recording method of this embodiment, the time from when droplets of the treatment liquid land on the recording medium in the treatment liquid applying step to when droplets of the first ink composition land on the recording medium in the first ink applying step is from 0.15 seconds to 0.25 seconds, and more preferably from 0.17 seconds to 0.23 seconds.

[0169] Furthermore, in the recording method of this embodiment, the time from when droplets of the treatment liquid land on the recording medium in the treatment liquid applying step to when droplets of the second ink composition land on the recording medium in the second ink applying step is 0.3 seconds or more and 0.6 seconds or less, and more preferably 0.35 seconds or more and 0.5 seconds or less.

[0170] If the time between the impact of the treatment liquid droplets on the recording medium and the impact of the ink droplets of the first ink composition on the recording medium is less than 0.15 seconds, insufficient filling and the occurrence of pinholes occur, and graininess also deteriorates. It is presumed that this is because if the time between the impact of the treatment liquid droplets on the recording medium and the impact of the ink droplets of the first ink composition on the recording medium is too short, the ink composition adheres before the treatment liquid has fully dried, causing the ink composition to react too quickly.

[0171] Furthermore, if the time between the impact of the treatment liquid droplets on the recording medium and the impact of the ink droplets of the second ink composition on the recording medium is longer than 0.6 seconds, uneven density occurs. It is presumed that this is because if the time between the impact of the treatment liquid droplets on the recording medium and the impact of the ink droplets of the second ink composition on the recording medium is long, the ink composition adheres in a state where the treatment liquid has dried too much, making it difficult for the reaction of the ink composition to proceed.

[0172] The treatment liquid, the first ink composition, and the second ink composition are ejected from their respective nozzle rows arranged in an inkjet head. Therefore, in the inkjet head, the nozzle row for the first ink composition is arranged closer to the nozzle row for the treatment liquid than the nozzle row for the second ink composition. This results in a difference in the time it takes for the first ink composition to land and the time it takes for the second ink composition to land after the treatment liquid has landed on the recording medium. The farther the nozzle row for the first ink composition is arranged from the nozzle row for the second ink composition, the greater the difference in the time it takes for the respective ink droplets to land.

[0173] The difference in time from the landing of the treatment liquid to the landing of the ink droplets of the first ink composition and the second ink composition can be changed by the arrangement of the nozzle rows in the inkjet head, the number of inks, the distance between the nozzle rows, the scanning speed of the inkjet head, etc. However, this time difference will occur as long as the nozzle row of the treatment liquid, the nozzle row of the first ink composition, and the nozzle row of the second ink composition are arranged in that order in the inkjet head. In the recording method of this embodiment, the shape of the nozzles in the inkjet head, the distance between the nozzles, the scanning speed of the inkjet head, etc. are adjusted so that the time until the landing of the ink droplets of the first ink composition and the second ink composition falls within the above range.

[0174] Furthermore, by setting the time from the impact of the treatment liquid to the impact of the ink droplets of the first ink composition and the second ink composition within the above-mentioned range, the degree of freedom in designing the inkjet head is increased, which is preferable. With such an inkjet head, the recording method of this embodiment is preferable because it can achieve excellent reductions in graininess and unevenness in density.

[0175] Ink compositions other than the first ink composition and the second ink composition may be ejected from other nozzle rows. In other words, the number of inks ejected from the nozzle rows during recording may be three or more. Furthermore, for example, the number may be 4 to 10. In this case, the first ink composition and the second ink composition may be any of the three or more inks.

[0176] Of all the inks used for recording in the recording method of this embodiment, it is preferable that the ink that lands the fastest after the treatment liquid lands has a time of 0.15 seconds or more from the time the treatment liquid lands, and that the ink that lands the slowest has a time of 0.6 seconds or less from the time the treatment liquid lands.

[0177] Furthermore, it is preferable that the time from the landing of the treatment liquid for each ink during recording is 0.15 seconds or more and 0.6 seconds or less. It is also preferable that another ink is landed between the landing of the first ink composition and the landing of the second ink composition. This is particularly preferable when a large number of inks are used, as it allows for excellent image quality to be obtained.

[0178] On the other hand, the time difference between the impact of the droplets of the first ink composition on the recording medium and the impact of the droplets of the second ink composition on the recording medium is preferably 0.1 to 0.5 seconds, which more significantly improves the graininess and pinhole filling of the resulting image, as well as the abrasion resistance.

[0179] 1.5.Other processes The recording method of this embodiment includes a step of applying a treatment liquid, a first ink composition, and a second ink composition to a recording medium. However, if necessary, the method may further include a step of applying a treatment liquid and one or more other ink compositions to a recording medium. Furthermore, there are no restrictions on the order or number of these steps, and they can be performed as needed. Furthermore, it is preferable that these other treatment liquids and inks are applied to the same area on the recording medium.

[0180] The recording method of this embodiment may include a drying step (primary heating step) for drying the liquid attached to the recording medium, a step for heating the recording medium (post-heating step), and the like.

[0181] 1.5.1. Drying process The recording method of this embodiment may have a drying step (primary drying step). The recording method of this embodiment may include a step of drying the recording medium before or during the application step of the treatment liquid or ink composition. The drying step can be carried out by stopping the recording and leaving it as it is, or by drying using a drying mechanism. The drying method using a drying mechanism includes a means for blowing air at room temperature or hot air onto the recording medium (air blowing type), and a drying method for drying the recording medium. Examples of such a method include a method of irradiating the recording medium with radiation (such as infrared rays) that generates heat (radiation method), a method of transferring heat to the recording medium by contacting the recording medium (conduction method), and a combination of two or more of these methods. If a drying step is included, it is more preferable to use an air blowing method.

[0182] Among the drying processes (primary drying processes), the case where a drying mechanism that heats the recording medium is used as the drying mechanism is particularly referred to as a heating process (primary drying process). For example, among the above drying mechanisms, a drying process that blows air at room temperature does not fall under the category of a heating process.

[0183] In this embodiment, since a certain level of image quality can be obtained by using the processing liquid, the primary heating step may not be performed, and furthermore, the primary drying step may not be performed.

[0184] Whether or not a primary drying step is performed, the surface temperature of the recording medium when the treatment liquid or ink composition is applied is preferably 45° C. or lower, and more preferably 20° C. or higher.

[0185] The temperature is more preferably 20° C. or higher and 45° C. or lower. Also, the temperature is preferably 27.0° C. or higher and 40° C. or lower, more preferably 28° C. or higher and 39° C. or lower. The temperature is further preferably 30 to 38° C., and more preferably 35 to 37° C.

[0186] This temperature is the surface temperature of the portion of the recording surface of the recording medium that receives the liquid during the application process, and is the highest temperature in the recording area during the application process. A surface temperature below the above range is more preferable in terms of reducing clogging. On the other hand, a surface temperature above the above range is more preferable in terms of better image quality and abrasion resistance.

[0187] If the surface temperature of the recording medium in the treatment liquid application step, the first ink application step, and the second ink application step is 45° C. or less, the graininess of the resulting image can be further improved.

[0188] The drying step can be carried out simultaneously with one or more of the treatment liquid application step and the ink application step. When the drying step is carried out simultaneously with the ink application step, the surface temperature of the recording medium is preferably 30°C or less, and more preferably 28°C or less.

[0189] When a drying step is carried out to dry the recording medium before or during the treatment liquid application step, the surface temperature of the recording medium at the time the treatment liquid is applied to the recording medium is 30.0° C. or higher, preferably 35.0° C. or higher, and more preferably 40.0° C. or higher. In this way, when the treatment liquid contains resin particles, for example, it becomes easier for the treatment liquid to form a film, which may further improve the adhesion and abrasion resistance of the obtained image.

[0190] Furthermore, each of the deposition steps does not have to be accompanied by a primary heating step, which can further improve the ejection stability of each ink, etc. Furthermore, each of the deposition steps does not have to be accompanied by a primary drying step.

[0191] 1.5.2. Post-heating process The recording method according to this embodiment may further include a post-heating step of heating the recording medium after each of the above-described adhesion steps. The post-heating step can be performed, for example, using an appropriate heating means. The post-heating step is performed, for example, by an after-heater (corresponding to heater 5 in the inkjet recording device example described below). The heating means is not limited to the heating means provided in the inkjet recording device, and other drying means may also be used. This dries the resulting image and allows it to be fixed more sufficiently, which, for example, allows the recorded material to be used sooner.

[0192] In this case, the temperature of the recording medium is not particularly limited, but can be set, for example, taking into consideration the Tg of the resin component that constitutes the resin particles contained in the recording material. When taking into consideration the Tg of the resin component that constitutes the resin particles and wax, it is recommended to set the temperature at least 5.0°C higher than the Tg of the resin component that constitutes the resin particles, and preferably at least 10.0°C higher.

[0193] The surface temperature of the recording medium reached by heating in the post-heating step is 30.0°C or higher and 120.0°C or lower, preferably 40.0°C or higher and 100.0°C or lower, more preferably 50.0°C or higher and 95°C or lower, and even more preferably 70°C or higher and 90°C or lower. The surface temperature of the recording medium reached by heating in the post-heating step is particularly preferably 80°C or higher. If the temperature of the recording medium is within this range, it is possible to coat and flatten the resin particles and wax contained in the recorded matter, and it is also possible to dry the resulting image and more fully fix it.

[0194] 1.6. Effects, etc. According to this recording method, the silicone surfactant used in the treatment liquid has a surface tension of 28.0 mN / m or less for both a 0.1% aqueous solution of the surfactant and a 0.1% propylene glycol solution of the surfactant, so that the graininess, buried pinholes, and uneven shading of the formed image can be improved.

[0195] Furthermore, according to this recording method, the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less, and the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less, so that the amount of water and organic solvent remaining in the treatment liquid after landing can be made appropriate, thereby achieving good wetting and spreading properties of the ink droplets when they come into contact with the droplets of the treatment liquid.

[0196] The wetting and spreading properties of ink droplets when they come into contact with droplets of treatment liquid are thought to be related to the surface tension of the treatment liquid at the time of contact. In this recording method, a surfactant is used in which the surface tension of a 0.1% aqueous surfactant solution and a 0.1% propylene glycol surfactant solution are both 28.0 mN / m or less, so the ink droplets that come into contact with the treatment liquid early after landing and the ink droplets that come into contact with the treatment liquid late after landing have similar wetting and spreading properties, which is thought to result in images with excellent graininess, filled pinholes, and uneven shading.

[0197] 2. Recording device The recording apparatus according to this embodiment is a recording apparatus that performs the above-described recording method, and includes a treatment liquid, a first ink composition, a second ink composition, and an inkjet head that ejects the treatment liquid, the first ink composition, and the second ink composition.

[0198] The treatment liquid and 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.

[0199] According to the recording apparatus of this embodiment, recording is performed by the above-described recording method, and therefore, the recording apparatus is excellent in recovering from nozzle clogging, image quality (bleed unevenness), and whitening reduction of printed matter.

[0200] The treatment liquid and 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.

[0201] 2.1.Serial Recording Device FIG. 1 is a schematic cross-sectional view showing a serial-type inkjet recording apparatus 19. FIG. 2 is a perspective view showing an example of the configuration of the periphery of the carriage of the inkjet recording apparatus 19 of FIG. 1. As shown in FIGS. 1 and 2, the inkjet recording apparatus 19 includes an inkjet head 29, an IR heater 391, a platen heater 49, a heating heater 59, a cooling fan 69, a preheater 79, a ventilation fan 89, a carriage 99, a platen 119, a carriage movement mechanism 139, a transport means 149, and a control unit CONT. The operation of the entire inkjet recording apparatus 19 is controlled by the control unit CONT shown in FIG. 2.

[0202] For example, the inkjet head 29 has the inkjet head 29a and the inkjet head 29b arranged symmetrically with respect to the sub-scanning direction SS so that the treatment liquid, the first ink composition, and the second ink composition can be deposited in this order during bidirectional scanning in the main scanning direction MS. When the carriage 99 scans in the S1 direction, the treatment liquid is ejected from the nozzle row of the inkjet head 29a located at the end in the S1 direction, the first ink composition is ejected from the nozzle row adjacent to the nozzle row from which the treatment liquid is ejected, and the second ink composition is ejected from the nozzle row of the inkjet head 29a located at the end in the S2 direction. Similarly, when the carriage 99 scans in the S2 direction, the treatment liquid is ejected from the nozzle row of the inkjet head 29b located at the end in the S2 direction, the first ink composition is ejected from the nozzle row adjacent to the nozzle row from which the treatment liquid is ejected, and the second ink composition is ejected from the nozzle row of the inkjet head 29b located at the end in the S1 direction.

[0203] Alternatively, recording may be performed by bidirectional scanning, and when the carriage 99 is scanned in the S1 direction, the treatment liquid is ejected from the nozzle row of inkjet head 29b located at the end in the S1 direction, the first ink composition is ejected from the nozzle row adjacent to the nozzle row from which the treatment liquid is ejected, and the second ink composition is ejected from the nozzle row of inkjet head 29a located second from the end in the S2 direction. Similarly, when the carriage 99 is scanned in the S2 direction, the treatment liquid is ejected from the nozzle row of inkjet head 29a located at the end in the S2 direction, the first ink composition is ejected from the nozzle row adjacent to the nozzle row from which the treatment liquid is ejected, and the second ink composition is ejected from the nozzle row of inkjet head 29b located second from the end in the S1 direction. This configuration may also be used, but in this case, the number of inks used for recording is eight, which is a large number and is therefore preferred.

[0204] Alternatively, when unidirectional printing is performed and the carriage 99 is scanned in the S1 direction, the treatment liquid is ejected from the nozzle row of the inkjet head 29b located at the end in the S1 direction, the first ink composition is ejected from the nozzle row adjacent to the nozzle row ejecting the treatment liquid, and the second ink composition is ejected from the nozzle row of the inkjet head 29a located at the end in the S2 direction. In this way, recording is performed by scanning only in the S1 direction. In this case, nine inks can be used, which is preferable.

[0205] The inkjet head 29 is a serial type inkjet head that scans multiple times in a main scanning direction MS relative to the recording medium M to deposit treatment liquid and ink composition (hereinafter also referred to as "ink, etc.") onto the recording medium M. The inkjet head 29 is mounted on a carriage 99 shown in FIG. 2. The inkjet head 29 is scanned multiple times in the main scanning direction relative to the recording medium M by the operation of a carriage movement mechanism 139 that moves the carriage 99 in the medium width direction of the recording medium M. The medium width direction is the main scanning direction of the inkjet head 29. Scanning in the main scanning direction is also called main scanning.

[0206] 3, the nozzle array that ejects the treatment liquid is inclined relative to the conveyance direction (direction T2) of the recording medium M. The nozzles are arranged horizontally at the same position as the nozzle row that ejects the ink composition. In this case, when the nozzle row that ejects the treatment liquid is projected along the head movement direction (MS), it is arranged so that it completely overlaps with the nozzle row that ejects the ink in the nozzle row direction (SS).

[0207] With this arrangement, the treatment liquid application step, first ink application step, and second ink application step in the above-mentioned recording method can be performed by scanning while moving the carriage relative to the recording medium, and the treatment liquid and the ink composition can be applied to the same scanning area in the same scanning step (single pass printing). The nozzle array shown in Figure 3 is the nozzle array that ejects ink, etc. in each inkjet head. 29, which includes 29a and 29b, represents the entire inkjet head.

[0208] The main scanning direction is the direction in which the carriage 99 carrying the inkjet head 29 moves. In FIG. 1, this direction intersects with the sub-scanning direction, which is the transport direction of the recording medium M, indicated by the arrow SS. In FIG. 2, the width direction of the recording medium M, i.e., the direction indicated by S1-S2, is the main scanning direction MS, and the direction indicated by T1→T2 is the sub-scanning direction SS. Note that scanning is performed in the main scanning direction, i.e., in either the direction indicated by the arrow S1 or the arrow S2, in one scan. Recording is performed on the recording medium M by repeating the main scan of the inkjet head 29 and the sub-scan, which transports the recording medium M, multiple times. In other words, the treatment liquid application process and the ink application process are performed by multiple main scans in which the inkjet head 29 moves in the main scanning direction, and multiple sub-scans in which the recording medium M moves in the sub-scanning direction that intersects the main scanning direction.

[0209] The cartridge 129 that supplies ink, etc. to the inkjet head 29 includes a plurality of independent cartridges. The cartridge 129 is detachably mounted on a carriage 99 that carries the inkjet head 29. 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 129 to each nozzle. Note that, in this embodiment, an example is shown in which the cartridge 129 is mounted on the carriage 99, but this is not limiting, and the cartridge 129 may be provided in a location other than the carriage 99 and ink may be supplied to each nozzle by a supply pipe (not shown).

[0210] A conventionally known method can be used for ejecting ink from the inkjet head 29. In this embodiment, a method of ejecting ink droplets using the vibration of a piezoelectric element, that is, an ejection method of forming ink droplets by the mechanical deformation of an electrostrictive element, is used.

[0211] The inkjet recording device 19 is equipped with a ventilation fan 89, an IR heater 391, and a platen heater 49 for drying ink and the like that is ejected from the inkjet head 29 and adhered to the recording medium M. The primary drying step can be performed by appropriately combining the ventilation fan 89, the IR heater 391, and the platen heater 49. In the primary drying step, it is not always necessary to heat the recording medium M, and the ventilation fan 89 may be used alone to blow air at room temperature.

[0212] Note that by using the IR heater 391, the recording medium M can be radiatively heated by radiating infrared rays from the inkjet head 29 side. This makes it easy for the inkjet head 29 to heat at the same time, but compared to heating from the back side of the recording medium M using a platen heater 49 or the like, the temperature can be increased without being affected by the thickness of the recording medium M. Also, various fans (for example, ventilation fan 89) are provided that blow warm air or air at the same temperature as the environment onto the recording medium M to dry the ink, etc. on the recording medium M.

[0213] The platen heater 49 is provided to heat the ink jet head 29 so that the ink, etc., discharged by the ink jet head 29 can be dried quickly from the time it is applied to the recording medium M. The recording medium M can be heated via a platen 119 at a position opposite the head 29. The platen heater 49 is capable of conducting heat to the recording medium M, thereby allowing ink or the like to adhere to the heated recording medium M.

[0214] With or without heating by the IR heater 391 and the platen heater 49, the upper limit of the surface temperature of the recording medium M is preferably 45° C. or less, more preferably 40° C. or less, even more preferably 35° C. or less, and even more preferably 30° C. or less. It is further preferably 25° C. or less. The lower limit is preferably 20° C. or more, more preferably 30° C. or more, and even more preferably 35° C. or more.

[0215] The heater 59 dries and solidifies the ink and other materials attached to the recording medium M, i.e., it is a heater for secondary heating or secondary drying. The heater 59 can be used in the secondary drying process. When the heater 59 heats the recording medium M on which an image has been recorded, the moisture contained in the ink and other materials evaporates and dissipates more quickly. In this way, the ink film is firmly fixed or adhered to the recording medium M, providing excellent film-forming properties, and an excellent, high-quality image can be obtained in a short time.

[0216] The upper limit of the surface temperature of the recording medium M heated by the heater 59 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. When the temperature is within the above range, high-quality images tend to be obtained in a short time.

[0217] The inkjet recording device 19 may have a cooling fan 69. After the ink recorded on the recording medium M is dried, the ink on the recording medium M is cooled by the cooling fan 69, thereby forming an ink coating film on the recording medium M with good adhesion.

[0218] The inkjet recording apparatus 19 may also include a preheater 79 that preheats the recording medium M before ink or the like is applied to the recording medium M. Furthermore, the inkjet recording apparatus 19 may also include a ventilation fan 89 so that the ink or the like applied to the recording medium M can dry more efficiently.

[0219] Below the carriage 99, there are provided a platen 119 that supports the recording medium M, a carriage movement mechanism 139 that moves the carriage 99 relative to the recording medium M, and a conveying means 149 that is a roller that conveys the recording medium M in the sub-scanning direction. The operations of the carriage movement mechanism 139 and the conveying means 149 are controlled by a control unit CONT.

[0220] 2.2. Lateral recording device 4 is a front view showing a typical example of a lateral recording device. The lateral recording device is a type of serial recording device, in which the carriage scan direction and the recording medium transport direction are the same.

[0221] 4 and 5, XYZ Cartesian coordinates with the Z axis as the vertical axis are also shown to clarify the positional relationship of each part of the device. In the following explanation, the direction of each coordinate axis (arrow) will be referred to as the positive direction, and the opposite direction as the negative direction. The recording device shown in FIG. 4 is also called a lateral recording device, as the recording medium is transported in a direction along the axis of the scanning direction.

[0222] The recording device 100 includes a host device 200 that generates print data from image data (bitmap data) received from an external device such as a personal computer, and a The printer unit 300 prints an image on the surface of the long sheet S using an inkjet method while transporting the long sheet S in a roll-to-roll manner.

[0223] 4, the printer unit 300 includes a main body case 1 having a substantially rectangular parallelepiped shape. Inside the main body case 1 are a feeding unit 2 that feeds out the sheet S from a roll R1 around which the sheet S is wound, a printing chamber 3 that ejects ink onto the surface of the fed sheet S to perform printing, a drying unit 4 that dries the sheet S with the ink attached, and a winding unit 5 that winds up the dried sheet S into a roll R2.

[0224] More specifically, the interior of the main body case 1 is divided into upper and lower sections in the Z-axis direction by a flat base 6 arranged parallel to the XY plane (i.e., horizontally), with the upper side of the base 6 being the printing chamber 3. In approximately the center of the printing chamber 3, a platen 30 is fixed to the upper surface of the base 6. The platen 30 has a rectangular shape, and supports the sheet S from below with its upper surface, which is parallel to the XY plane. A recording unit 31 then prints on the surface of the sheet S supported on the platen 30.

[0225] Meanwhile, below the base 6, the unwinding unit 2, the drying unit 4, and the winding unit 5 are arranged. The unwinding unit 2 is arranged below the platen 30 in the negative direction of the X axis (diagonally downward left in FIG. 4), and includes a rotatable unwinding spindle 21. The sheet S is wound around this unwinding spindle 21 to support a roll R1. The winding unit 5 is arranged below the platen 30 in the positive direction of the X axis (diagonally downward right in FIG. 1), and includes a rotatable winding spindle 51. The sheet S is wound around this winding spindle 51 to support a roll R2. The drying unit 4 is arranged directly below the platen 30, between the unwinding unit 2 and the winding unit 5 in the X axis direction.

[0226] The sheet S fed from the feed shaft 21 of the feed unit 2 passes through the printing chamber 3 and the drying unit 4 in that order while being guided by rollers 71 to 77, and is then wound up around the winding shaft 51 of the winding unit 5. The rollers 72 and 73 are arranged side by side in a straight line in the X-axis direction (i.e., horizontally) with the platen 30 between them, and are positioned so that their tops are flush with the upper surface of the platen 30 (the surface that supports the sheet S). Therefore, the sheet S wound around roller 72 moves horizontally (in the X-axis direction) while sliding against the upper surface of the platen 30 until it reaches roller 73.

[0227] In the printing chamber 3, a printing process is carried out on the sheet S by a recording unit 31 arranged above the platen 30. This recording unit 31 prints an image on the surface of the sheet S by ejecting a treatment liquid and an ink composition onto the surface of the sheet S. Here, a cartridge mounting section 8 is provided at the end of the printing chamber 3 in the negative direction of the X axis (the left end in FIG. 4), and a treatment liquid cartridge 81 that stores the above-mentioned treatment liquid and a plurality of ink cartridges 82 that store the above-mentioned ink composition are detachably mounted in the cartridge mounting section 8. The recording unit 31 is capable of ejecting the treatment liquid supplied from the treatment liquid cartridge 81 and the ink composition supplied from the ink cartridges 82 onto the surface of the sheet S by an inkjet system.

[0228] FIG. 5 is a bottom view partially showing the configuration of the recording unit. In this example, the recording unit 31 will be described in detail with reference to FIGS. 4 and 5. The recording unit 31 has a carriage 32, a flat support plate 33 attached to the underside of the carriage 32, and an inkjet head 34 for treatment liquid and an inkjet head 35 attached to the underside of the support plate 33. On the underside of the support plate 33, four inkjet heads 35 for ink and one inkjet head 34 for treatment liquid are arranged at equal pitches in the X-axis direction, and each inkjet head In the heads 34 and 35, a plurality of nozzles N (nozzle rows) are arranged in parallel in the Y-axis direction. The treatment liquid inkjet head 34 ejects treatment liquid from the nozzles N, and the four inkjet heads 35 eject ink of different colors from the nozzles N.

[0229] In this embodiment, the first ink composition is ejected from the inkjet head 35 for ink located next to the inkjet head 34 for treatment liquid, and the second ink composition is ejected from the inkjet head 35 for ink located farthest from the inkjet head 34 for treatment liquid.

[0230] The length in the Y-axis direction of the nozzle rows of the treatment liquid inkjet head 34 and the ink inkjet head 35 is preferably equal to or greater than the length in the Y-axis direction of the sheet S (recording medium). Inkjet heads having such lengths enable recording in one pass and are excellent in recording speed, but the amount of ink deposited is large, making bleeding unevenness more likely to occur. In contrast, the recording apparatus according to this embodiment uses the above-mentioned recording method, and therefore tends to be able to achieve excellent image quality (bleed unevenness) even when recording in one pass.

[0231] 5, when the nozzle row of the treatment liquid inkjet head 34 that ejects the treatment liquid is projected along the head movement direction (X-axis direction), it is arranged so that it completely overlaps in the nozzle row direction (Y-axis direction) with the nozzle row of the inkjet head 35 that ejects the ink. With this arrangement, the treatment liquid application step and each ink application step in the above-mentioned recording method can be performed by scanning while moving the inkjet head for treatment liquid and the inkjet head for ink relative to the recording medium, and can be performed in a mode where the treatment liquid and the ink composition are applied to the same scanned area during the same scan (completely simultaneous ejection).

[0232] The inkjet head of the recording unit may be the inkjet head 29 of FIG. 3, but in this example, the inkjet head of FIG. 5 is used. 5 may be used as the inkjet head of the recording unit of the recording apparatus of FIG. Although the number of inkjet heads in Figure 5 is five, the number of inkjet heads may be three or more, for example, 7 to 20 or less. The number of inkjet heads is also the number of nozzle rows. An inkjet head is a unit that ejects one ink or treatment liquid, and is also a nozzle row. The number of ink jet heads may also be used as the number of inks.

[0233] Returning to Figure 4, the explanation will continue. The carriage 32 of the recording unit 31 configured as described above is movable integrally with the support plate 33, the treatment liquid inkjet head 34, and the ink inkjet head 35. In other words, an X-axis guide rail 37 extending parallel to the X-axis direction is provided inside the printing chamber 3, and when the carriage 32 receives the driving force of the X-axis motor, it moves in the X-axis direction along the X-axis guide rail 37.

[0234] The recording unit 31 then moves (scans) a carriage 32 above the platen 30 in the X-axis direction (main scanning direction, scanning direction), while ejecting treatment liquid from the treatment liquid inkjet head 34 and ink from the inkjet head 35, depositing the treatment liquid and the ink composition in the same scanning area in the same scanning operation, thereby printing an image on the surface of the sheet S, which is stopped on the upper surface of the platen 30. As a result, a two-dimensional image for one frame is printed on the surface of the sheet S, the length of the nozzle row in the Y direction and the scanning distance in the X-axis direction. Furthermore, the coloring material of the ink that makes up the two-dimensional image is coagulated by the action of the treatment liquid and fixed to the surface of the sheet S.

[0235] The printing of one frame as described above is repeatedly performed while the sheet S is moved intermittently in the X-axis direction. Specifically, the printing area is a predetermined range that covers almost the entire upper surface of the platen 30. The sheet S is then intermittently transported in the X-axis direction in units of a distance (intermittent transport distance) that corresponds to the length of this printing area in the X-axis direction, and one frame is printed on the sheet S that stops on the upper surface of the platen 30 during the intermittent transport. In other words, when printing of one frame on the sheet S that stops on the platen 30 is completed, the sheet S is transported in the X-axis direction by the intermittent transport distance, and the unprinted side of the sheet S stops on the platen 30. Next, printing of a new frame is performed on this unprinted side, and when this is completed, the sheet S is again transported in the X-axis direction by the intermittent transport distance. This series of operations is then repeatedly performed.

[0236] Recording one frame on a stopped recording medium may be performed in one pass as described above, or in two or more passes. When performing recording in two or more passes, the inkjet head may be moved in the Y direction between passes. This is preferable because it allows for increased recording resolution in the Y direction. 10 passes or less is preferable, and 4 passes or less is more preferable.

[0237] Note that, in order to keep the sheet S stopped on the upper surface of the platen 30 flat during intermittent transport, the platen 30 may be equipped with a mechanism for sucking the sheet S stopped on its upper surface. Specifically, the upper surface of the platen 30 has a large number of suction holes (not shown), and a suction unit 38 is attached to the lower surface of the platen 30. When the suction unit 38 operates, negative pressure is generated in the suction holes on the upper surface of the platen 30, and the sheet S is sucked to the upper surface of the platen 30. Then, while the sheet S is stopped on the platen 30 for printing, the suction unit 38 sucks the sheet S, thereby keeping the sheet S flat. On the other hand, when printing is completed, the suction unit 38 stops sucking the sheet S, allowing the sheet S to be transported smoothly.

[0238] A heater 39 may be attached to the underside of the platen 30. This heater 39 can heat the platen 30 to a predetermined temperature (for example, 30°C) as needed. This allows the sheet S to be primarily dried by the heat of the platen 30 while undergoing printing processing by the treatment liquid inkjet head 34 and the ink inkjet head 35.

[0239] However, in the recording apparatus according to this embodiment, the recording medium may be heated in a location where the ink composition is deposited, such as on the platen 30, using a heating mechanism (e.g., heater 39) for heating the recording medium provided on a member that supports the recording medium, or a heating mechanism (not shown) for heating the recording medium from above. Examples of heating mechanisms for heating the recording medium from above include a blower fan and an IR heater. However, even when heating is performed, the surface temperature of the recording medium when the ink is deposited may be the same as in the example recording apparatus shown in FIG. 1.

[0240] This makes it easier to keep the surface temperature of the recording medium at 45° C. or less, preferably 35° C. or less, when the ink is applied, which tends to result in better clogging recovery.

[0241] In this way, the sheet S that has received one frame of printing moves from the platen 30 to the drying unit 4 as the sheet S is intermittently transported. This drying unit 4 is capable of carrying out a post-heating step in which the treatment liquid and ink composition that have landed on the sheet S are completely dried using air heated for drying.

[0242] In the drying section 4, the surface temperature that the sheet S reaches may be the same as that of the example of the recording device in FIG. 1, and is set to 30.0°C or higher and 120.0°C or lower, preferably 40.0°C or higher and 100.0°C or lower, more preferably 50.0°C or higher and 95°C or lower, and further preferably 70°C or higher and 90°C or lower. It is preferable to heat the mixture so that the temperature becomes

[0243] The sheet S that has been subjected to the drying process then reaches the winding section 5 as the sheet S is intermittently transported, and is wound up into a roll R2.

[0244] Figure 6 shows another example of the inkjet head of the recording unit of Figures 3 and 5. In Figure 6, as in Figure 5, an inkjet head 32d for treatment liquid and inkjet heads 32a to 32c for ink are arranged on a support plate 33. In the example of Figure 6, each of the inkjet heads 32a to 32d is configured with a plurality of unit heads 34 arranged in the Y direction. Each unit head 34 has a nozzle row N. In one inkjet head, there are portions where the nozzle positions in the X direction differ between nozzles. In particular, there are portions where the nozzle positions in the X direction differ between unit heads.

[0245] Constructing an inkjet head in this manner is preferable because it is easy to manufacture an inkjet head that is long in the Y direction. In this case, the length of the entire inkjet head in the X direction tends to be long, and the recording method of this embodiment is particularly useful and preferable. The length of the entire inkjet head in the X direction is the length from the nozzle of the inkjet head at one end in the X direction to the nozzle of the inkjet head at the other end.

[0246] In the example of Figure 6, there are three inkjet heads for each ink, but the number is not limited to three and may be two or more, for example, 2 to 20. The same applies to Figures 3 and 5. In this case, the number of inks can be increased and multi-color printing becomes possible, but the length of the entire inkjet head in the X direction tends to be longer, and this embodiment is particularly useful. Also, similar to the example of FIG. 3, two inkjet heads for the treatment liquid may be provided.

[0247] In each figure, the nozzle distance between the inkjet head for the treatment liquid and the inkjet head for the first ink is preferably 30 to 230 mm, more preferably 50 to 200 mm, even more preferably 100 to 190 mm, and particularly preferably 130 to 180 mm. The nozzle distance between the inkjet head for the treatment liquid and the inkjet head for the second ink is preferably 200 to 500 mm, more preferably 250 to 400 mm, even more preferably 300 to 360 mm, and particularly preferably 320 to 340 mm.

[0248] The scanning speed is preferably 200 to 1500 mm / sec, more preferably 500 to 1000 mm / sec, and even more preferably 600 to 800 mm / sec. The scanning speed is the inkjet head movement speed in the serial type and the recording medium conveyance speed in the line type.

[0249] In these cases, it is easy to achieve the difference in landing times of the treatment liquid ink as in this embodiment, which is preferable in terms of the degree of freedom in designing the recording apparatus.

[0250] 7 shows an example of a line-type recording apparatus. The line-type recording apparatus 1 includes a feeding section 10 for a recording medium F, a conveying section 20, a recording section 30, a drying device 90, and a discharge section 70.

[0251] The drying device 90 has a first drying section 40 that performs a drying step and a second drying section 50 that performs a post-heating step.

[0252] The feeding unit 10 is provided so as to be able to feed a rolled recording medium F to the transport unit 20. The feeding unit 10 has a rolled medium holder 11, which holds the rolled recording medium F. The rolled recording medium F is then rotated to feed the recording medium F to the transport unit 20 downstream in the feed direction Y.

[0253] The transport unit 20 transports the recording medium F sent from the feeding unit 10 to the recording unit 30. The transport unit 20 has a first feed roller 21, and is configured to be able to transport the sent recording medium F further to the recording unit 30 downstream in the feed direction Y.

[0254] The recording unit 30 has an inkjet head R that ejects a treatment liquid onto the recording medium F sent from the transport unit 20, and an inkjet head H that ejects ink.

[0255] The configuration of the inkjet head is not limited to this, and the inkjet head for the treatment liquid may be arranged at the most upstream position in the Y direction in FIG. 7, without using the configurations shown in FIGS. 3, 5 and 6 described above.

[0256] The recording medium is also provided with a platen 34 as a recording medium support portion that supports the recording medium from the back when ink or the like is attached.

[0257] A second feed roller 43 is provided downstream in the feed direction Y from the platen 34. The second feed roller 43 is configured to be able to feed the recorded recording medium F to a second drying section 50 located downstream in the feed direction Y.

[0258] A third feed roller 65 is provided near the outlet 64 of the second drying section 50. The third feed roller 65 is disposed so as to come into contact with the back surface of the recording medium F, and is configured to be able to feed the recording medium F to the discharge section 70 located downstream in the feed direction Y.

[0259] The discharge section 70 is provided so as to send the recording medium F sent from the second drying section 50 further downstream in the feed direction Y and discharge it to the outside of the inkjet recording apparatus 1. The discharge section 70 has a fourth feed roller 71, a fifth feed roller 72, a sixth feed roller 73, a seventh feed roller 74, and a take-up roller 75.

[0260] As described above, a line-type recording device performs recording by scanning, in which treatment liquid and ink are ejected from the inkjet head onto a recording medium F being fed to the inkjet head. In this way, recording is performed by scanning, which is the movement of the relative positions of the inkjet head and the recording medium. Furthermore, the deposition of treatment liquid and the deposition of ink are performed in the same scanning area during the same scan. Note that recording is performed in a single scan.

[0261] According to the recording apparatus of this embodiment, recording is performed by the above-mentioned recording method, and since the silicone surfactant used in the treatment liquid is a surfactant whose surface tension is 28.0 mN / m or less for both a 0.1% aqueous solution of surfactant and a 0.1% propylene glycol solution of surfactant, it is possible to form an image with good graininess, buried pinholes, and uneven shading.

[0262] Furthermore, with this recording device, the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less, and the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less, so that the amount of water and organic solvent remaining in the treatment liquid after landing can be made appropriate, thereby achieving good wetting and spreading properties of the ink droplets when they come into contact with the droplets of the treatment liquid.

[0263] The recording method of this embodiment can be performed by a serial type recording apparatus as in the above example, or by a line type recording apparatus. As with the serial type recording apparatus, if the inkjet heads are appropriately positioned in the line type recording apparatus, the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium can be reduced. It will be understood that the time can be 0.15 seconds or more and 0.25 seconds or less, and the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium can be 0.3 seconds or more and 0.6 seconds or less.

[0264] 3. Processing solution The treatment liquid according to this embodiment is a treatment liquid used in the above-described recording method, and is an aqueous treatment liquid containing a coagulant. It contains a silicone surfactant, and the silicone surfactant includes a silicone surfactant a, the surface tension of which in a 0.1% aqueous solution is 28.0 mN / m or less, and the surface tension of which in a 0.1% propylene glycol solution is 28.0 mN / m or less.

[0265] This treatment liquid uses a silicone surfactant whose surface tension is 28.0 mN / m or less for both a 0.1% aqueous solution of the surfactant and a 0.1% propylene glycol solution of the surfactant, so that the graininess, buried pinholes, and uneven shading of the formed image can be improved.

[0266] Furthermore, this treatment liquid allows the amount of water and organic solvent remaining on the recording medium to be appropriate after impact, thereby improving the wetting and spreading properties of ink droplets when they come into contact with droplets of the treatment liquid.

[0267] 4. Examples and Comparative Examples The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Hereinafter, "parts" and "%" are based on mass unless otherwise specified. The evaluations were carried out in an environment of a temperature of 25.0°C and a relative humidity of 40.0%, unless otherwise specified.

[0268] 4.1. Preparation of ink and treatment liquid The components were mixed in a container to obtain the compositions shown in Tables 1 and 2, stirred for 2 hours, and then filtered using a 5.0 μm PTFE membrane filter to obtain treatment liquids (R1 to R16), first ink compositions (C1-1 to C1-2), and second ink compositions (C2-1 to C2-2). The values ​​in the tables indicate mass %. Pure water was used, and was added so that the mass of each composition was 100 mass %. The pigment and dispersant resin were prepared as dispersions described below and used.

[0269] Among the components shown in Tables 1 and 2, the components other than the compound names are as follows: Cationic polymer: "Catiomaster PD-7, polyamine resin (epichlorohydrin-amine derivative resin)" manufactured by Yokkaichi Synthetic Co., Ltd. BYK-3420: Silicone surfactant (manufactured by BYK Japan), satisfies condition (a). BYK-3480: Silicone surfactant (manufactured by BYK Japan), satisfies condition (a). SAG002: Silface SAG002 (manufactured by Nissin Chemical Industry Co., Ltd.), does not satisfy condition (a). SAG503A: Silface SAG002 (manufactured by Nissin Chemical Industry Co., Ltd.), does not satisfy condition (a). SAG005: Silface SAG002 (manufactured by Nissin Chemical Industry Co., Ltd.), does not satisfy condition (a). BYK-333: Silicone surfactant (manufactured by BYK Japan), does not satisfy condition (a). BYK-348 silicone surfactant (manufactured by BYK Japan), condition (a) Does not satisfy. BYK-349 silicone surfactant (manufactured by BYK Japan) does not satisfy condition (a). · 1,2-HD: 1,2-hexanediol. · 2P: 2-pyrrolidone. Carbon black: No. 33 (Mitsubishi Chemical) Cyan pigment: CI Pigment Blue 15:3 Dispersion resin, Resin A (anionic): Acrylic acid-acrylate copolymer (weight average molecular weight: 25,000, acid value: 75) Dispersion resin, resin B (nonionic): acrylic acid-acrylate copolymer (weight average molecular weight: 25,000, acid value: 30) Resin particles, styrene acrylic: see below (high cohesiveness) Wax, polyethylene: Nopcoat PEM-17 (product name, manufactured by San Nopco Ltd.) Ink surfactant: Silicone surfactant "BYK348" manufactured by BYK

[0270] (Resin particles: Preparation of styrene acrylic resin) A resin emulsion was obtained by emulsion copolymerization of styrene and an acrylic monomer. The surfactant used for emulsion polymerization was Newcol NT-30 (manufactured by Nippon Nyukazai Co., Ltd.), and the amount used was 1 part by mass per 100 parts by mass of the total amount of monomers.

[0271] (Preparation of pigment dispersion) <Pigment dispersion liquid using resin A> First, 12 parts by mass of Resin A as a resin dispersant was added and dissolved in 155 parts by mass of ion-exchanged water in which 0.1 parts by mass of 30% aqueous ammonia solution (neutralizer) had been dissolved. 40 parts by mass of pigment (CI Pigment Blue 15:3 or carbon black: No. 33) was added, and the mixture was dispersed in a ball mill using zirconia beads for 10 hours. Subsequently, the mixture was centrifuged using a centrifuge to remove impurities such as coarse particles and dust, and the colorant concentration was adjusted to 20% by mass, yielding a colorant dispersion.

[0272] <Pigment dispersion liquid using resin B> A colorant dispersion liquid was obtained in the same manner except that Resin B was used as the resin dispersant.

[0273] <Silicone surfactant preparation example 1> The silicone surfactant Preparation Example 1 was synthesized as follows. To a 20 mL solution of 7.0 g of heptaethylene glycol monoallyl ether was added 5.8 g of a compound in which dimethylpolysiloxane having 19 Si atoms and -H bonds to the Si atoms at both ends and 0.1 mL of chloroplatinic acid, and the mixture was stirred and maintained at 65°C for 24 hours to allow the reaction to occur. After completion of the reaction, the solvent was removed by rotary evaporation, yielding Silicone Surfactant Preparation Example 1.

[0274] The structure of Silicone Surfactant Preparation Example 1 is represented by formula (1): a=17, x, y=3, n, m=7, o, p=0, R 1 , R 2 = hydroxy group, is.

[0275] The conditions for GPC measurement for each silicone surfactant were as follows: [Measurement conditions] Solvent: Tetrahydrofuran Column: TSKgel Super HZM-N x 2 · +TSKgel guardcolumn SuperHZ-L Column temperature: 40℃ ·Injection volume: 25μL Detector: Differential Refractive Index (RI) ·Flow rate: 0.35mL / min Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) A calibration curve using 13 samples with Mw = 1,000,000 to 500 was used. For each silicone surfactant, a 0.1% by mass aqueous solution of the surfactant and a 0.1% by mass propylene glycol solution of the surfactant were prepared, and the surface tension was measured as described above. The measured values ​​for each silicone surfactant are summarized in Table 6.

[0276] In each table, whether or not the silicone surfactant in the treatment liquid satisfies condition (a) that the surface tension of a 0.1% aqueous solution of the surfactant is 28.0 mN / m or less, and the surface tension of a 0.1% propylene glycol solution of the surfactant is 28.0 mN / m or less, is indicated as "Y" if it is satisfied, and as "N" if it is not satisfied.

[0277] 4.2.Evaluation Method 4.2.1. Thickening rate The "viscosity increase when mixed at a mass ratio of 10:1 (ink: 7% by mass calcium formate aqueous solution)" in Table 2 was measured by mixing each ink with a 7% by mass calcium formate aqueous solution at a mass ratio of 10:1, stirring for 1 minute, and then measuring the viscosity using a rheometer (MCR302 / Anton Paar) at 25°C and a shear rate of 200 s -1 The viscosity of the mixed liquid after mixing is the ratio of the viscosity of the ink before mixing when measured under the conditions of 1. The results are shown in Table 2.

[0278] 4.2.2. Recording test The ink and treatment liquid of each example were filled into a modified SurePress L-4733A digital label printer. The recording device shown in Figure 4 was used, and the inkjet head configuration shown in Figure 6 was used. However, the number of inkjet heads was set to five.

[0279] The recording resolution was based on 1200 x 1200 dpi, and the number of droplets per pixel was adjusted so that the deposition amount of each composition was the value shown in Tables 3 to 5. The temperature of the primary heating is shown in the tables as the surface temperature of the recording medium. Secondary heating was performed by heating to 70°C using a secondary heater installed downstream from the head. PET50A (manufactured by Lintec Corporation) was used as the recording medium. Each test was performed under the conditions shown in Tables 3 to 5. Tables 3 to 5 also show the time difference [s] between the treatment liquid and the ink, which is the time from the impact of the treatment liquid droplets on the recording medium to the impact of the ink droplets of the first ink on the recording medium, and the time from the impact of the treatment liquid droplets on the recording medium to the impact of the ink droplets of the second ink composition on the recording medium. The weight of each ejected droplet is shown in the tables.

[0280] The inkjet head at one end was filled with the treatment liquid, the inkjet head closest to the treatment liquid inkjet head was filled with the first ink, and the inkjet head at the other end was filled with the second ink.

[0281] In Example 1, the nozzle distance between the inkjet head for the treatment liquid and the inkjet head for the first ink was 150 mm, and the nozzle distance between the inkjet head for the treatment liquid and the inkjet head for the second ink was 338 mm. In examples with different time differences between the treatment liquid and the ink, the position of the inkjet head for the ink was changed in the X direction.

[0282] Recording was performed by scanning the carriage in the direction of the inkjet head for the treatment liquid, and was performed in one pass. The scanning speed was 750 mm / sec.

[0283] 4.2.3. Image Filling and Pinhole Evaluation The amount of adhesion was 1.5 mg / inch. 2 1st ink: 3.5mg / inch 2 , 2nd ink 3.5mg / inch 2 A test pattern was recorded with the solid image areas of the resulting recordings visually observed under fluorescent light and evaluated according to the following criteria. A: There are no unfilled areas or pinholes. B: Some unfilled areas and pinholes are visible. C: Unfilled areas and pinholes are clearly visible.

[0284] 4.2.4.Evaluation of Image Graininess The amount of adhesion is 1.5 mg / inch 2 , 1st ink: 1.8mg / inch 2 , 2nd ink 1.8mg / inch 2 The image area of ​​the resulting print was visually observed under a fluorescent lamp and evaluated according to the following criteria. A: The dots have no graininess. B: The dots are slightly grainy. C: The graininess of the dots is clearly visible.

[0285] 4.2.5. Evaluation of Image Shading The amount of adhesion is 1.5 mg / inch2 , 1st ink: 4.5mg / inch 2 , 2nd ink 4.5mg / inch 2 A test pattern was recorded in which the ink was superimposed and adhered with the ink, and the solid image area of ​​the resulting recorded matter was visually observed under a fluorescent lamp and evaluated according to the following criteria. A: There is no unevenness in the shade. B: Some unevenness in shade is visible. C: Significant unevenness in shading is visible.

[0286] In this specification, image density unevenness refers to unevenness caused by ink droplets gathering on the recording medium, known as aggregation unevenness, bleed unevenness, etc. Image density unevenness varies mainly due to the aggregation of ink droplets, their reaction with the treatment liquid, and the degree of drying.

[0287] 4.2.6. Evaluation of image scratch resistance The amount of adhesion (treatment liquid: 3 mg / inch 2 , 1st ink: 4mg / inch 2 , 2nd ink: 4mg / inch 2 , and the total amount of treatment liquid and ink adhered was set to 11 mg / inch 2 The ink was then applied over the other sheets and a test pattern was printed. The secondary heating was performed after drying for 2 minutes in a 70°C environment, and the following evaluation was then performed. The ink-applied area was cut into a 30 x 150 mm rectangle and rubbed 50 times with a plain woven cloth moistened with water using a Gakushin-type abrasion resistance tester (load 500 g). The degree of ink peeling was visually observed and evaluated according to the following criteria. A: In the Gakushin abrasion resistance test, no peeling occurred when rubbed 10 times with a load of 500g. B: In the Gakushin abrasion resistance test, peeling occurred when rubbed 10 times with a load of 500g, but the peeling was within 10% of the evaluation area. C: In the Gakushin abrasion resistance test, peeling occurred in more than 10% of the sample when rubbed 10 times with a load of 500g.

[0288] 4.3.Evaluation Results the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink land on the recording medium is 0.15 seconds or more and 0.25 seconds or less, and the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink land on the recording medium is 0.3 seconds or more and 0.6 seconds or less, or Furthermore, it was found that the recording method of each example in which the treatment liquid contains a silicone surfactant that satisfies condition (a) can improve the graininess, filled pinholes, and uneven shading of the formed image.

[0289] Although not shown in the table, similar evaluation results were obtained when the recording conditions were the same as for a line-type recording device such as that shown in Figure 7. This can also be achieved with a line-type recording device.

[0290] In addition, a yellow ink was prepared by replacing the colorant in the first ink with PY150, and a magenta ink was prepared by replacing it with PR120. These were filled into inkjet heads other than those used for the treatment liquid, first ink, and second ink, and recording was performed using the four inks. The amount of each ink deposited was made equal so that the total amount of ink deposited was the same as in each example, and the same evaluation results were obtained. The same can be achieved with three or more inks.

[0291] When we tried to use the SC-R5050 and SC-S80650 (both manufactured by Seiko Epson) as recording devices, the length of the carriage in the scanning direction was too short, and it was not possible to use the same inkjet head configuration as above.

[0292] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0293] The following can be derived from the above-described embodiment and modifications.

[0294] The recording method is a treatment liquid application step of ejecting the treatment liquid from an inkjet head and applying it to the recording medium; a first ink deposition step of ejecting the first ink composition from an inkjet head and depositing it on a recording medium; a second ink deposition step of ejecting the second ink composition from an inkjet head and depositing it on a recording medium, the treatment liquid is an aqueous treatment liquid containing a flocculant, the first ink composition and the second ink composition are water-based ink compositions containing a coloring material, In a scanning operation in which the relative positions of the inkjet head and the recording medium are moved, the treatment liquid, the first ink composition, and the second ink composition are deposited on the recording medium in the same scanning operation for the same scanning region; the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less; the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less; the treatment liquid contains a silicone surfactant, The silicone surfactant includes a silicone surfactant a, The silicone surfactant a is a silicone surfactant in which the surface tension of a 0.1% by mass aqueous solution of the surfactant is 28.0 mN / m or less, and the surface tension of a 0.1% by mass propylene glycol solution of the surfactant is 28.0 mN / m or less.

[0295] According to this recording method, the silicone surfactant used in the treatment liquid is surfactant 0. The surfactant used has a surface tension of 28.0 mN / m or less for both a 0.1% aqueous solution and a 0.1% propylene glycol solution of the surfactant, so the graininess, buried pinholes, and uneven shading of the formed image can be improved.

[0296] Furthermore, according to this recording method, the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less, and the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less, so that the amount of water and organic solvent remaining in the treatment liquid after landing can be made appropriate, thereby achieving good wetting and spreading properties of the ink droplets when they come into contact with the droplets of the treatment liquid.

[0297] The wetting and spreading properties of ink droplets when they come into contact with droplets of treatment liquid are thought to be related to the surface tension of the treatment liquid at the time of contact. In this recording method, a surfactant is used in which the surface tension of a 0.1% aqueous surfactant solution and a 0.1% propylene glycol surfactant solution are both 28.0 mN / m or less, so the ink droplets that come into contact with the treatment liquid early after landing and the ink droplets that come into contact with the treatment liquid late after landing have similar wetting and spreading properties, which is thought to result in images with excellent graininess, filled pinholes, and uneven shading.

[0298] In the above recording method, The content of the silicone surfactant a in the treatment liquid may be 0.1% by mass or more and 1.5% by mass or less.

[0299] According to this recording method, the graininess and pinhole filling of the obtained image, as well as the abrasion resistance, can be further improved.

[0300] In the above recording method, The first ink composition and the second ink composition may each have a viscosity increase of 5 times or more when mixed with a 7 mass % aqueous solution of calcium formate at a mass ratio (ink composition:aqueous solution) of 10:1.

[0301] According to this recording method, the resulting image can be made even more uniform in density.

[0302] In the above recording method, The droplet of the treatment liquid may have a mass of 1 ng or more and 7.0 ng or less.

[0303] According to this recording method, the resulting image can be made even more uniform in density.

[0304] In the above recording method, The surface temperature of the recording medium in the treatment liquid application step, the first ink application step, and the second ink application step may be 45° C. or lower.

[0305] According to this recording method, the graininess of the resulting image can be further improved.

[0306] In the above recording method, The silicone surfactant a may be a silicone surfactant having a maximum peak in the molecular weight range of 300 or more in the molecular weight range of 1000 to 3000 in the molecular weight distribution in gel permeation chromatography.

[0307] According to this recording method, the abrasion resistance of the resulting image can be further improved.

[0308] In the above recording method, The time difference between when the droplets of the first ink composition land on the recording medium and when the droplets of the second ink composition land on the recording medium may be 0.1 seconds or more and 0.5 seconds or less.

[0309] According to this recording method, the graininess and pinhole filling of the obtained image, as well as the abrasion resistance, can be further improved.

[0310] In the above recording method, The treatment liquid may contain an organic solvent that is a polyol having a normal boiling point of 170°C or higher and 240°C or lower.

[0311] According to this recording method, the graininess and abrasion resistance of the resulting image can be further improved.

[0312] In the above recording method, The treatment liquid may contain no more than 5% by mass of a nitrogen-containing solvent.

[0313] According to this recording method, the graininess and abrasion resistance of the resulting image can be further improved.

[0314] The recording device A recording device that performs the above-mentioned recording method, the treatment liquid, the first ink composition, and the second ink composition; an inkjet head that ejects the treatment liquid, the first ink composition, and the second ink composition; It has.

[0315] According to this recording device, the silicone surfactant used in the treatment liquid has a surface tension of 28.0 mN / m or less for both a 0.1% aqueous solution of the surfactant and a 0.1% propylene glycol solution of the surfactant, so that the graininess, buried pinholes, and uneven shading of the formed image can be improved.

[0316] Furthermore, with this recording device, the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less, and the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less, so that the amount of water and organic solvent remaining in the treatment liquid after landing can be made appropriate, thereby achieving good wetting and spreading properties of the ink droplets when they come into contact with the droplets of the treatment liquid.

[0317] The ink set is A recording method as described above, The ink jet recording medium includes the treatment liquid, the first ink composition, and the second ink composition.

[0318] According to this ink set, the treatment liquid contains a silicone surfactant such that the surface tension of a 0.1% aqueous solution of the surfactant and the surface tension of a 0.1% propylene glycol solution of the surfactant are both 28.0 mN / m or less, thereby enabling the image formed with the ink composition to have good graininess, filled pinholes, and uneven shading.

[0319] Furthermore, with this ink set, the amount of water and organic solvent remaining on the recording medium after impact can be controlled appropriately, thereby improving the wetting and spreading properties of the ink droplets when they come into contact with droplets of the treatment liquid.

[0320] The processing liquid is A processing liquid used in the above-mentioned recording method, The treatment liquid is an aqueous solution containing a flocculant, Contains silicone surfactants, The silicone surfactant includes a silicone surfactant a having a surface tension of 28.0 mN / m or less in a 0.1% aqueous solution of the surfactant and a surface tension of 28.0 mN / m or less in a 0.1% propylene glycol solution of the surfactant.

[0321] This treatment liquid uses a silicone surfactant whose surface tension is 28.0 mN / m or less for both a 0.1% aqueous solution of the surfactant and a 0.1% propylene glycol solution of the surfactant, so that the graininess, buried pinholes, and uneven shading of the formed image can be improved.

[0322] Furthermore, this treatment liquid allows the amount of water and organic solvent remaining on the recording medium to be appropriate after impact, thereby improving the wetting and spreading properties of ink droplets when they come into contact with droplets of the treatment liquid. [Explanation of symbols]

[0323] 19... inkjet recording device, 29... inkjet head (29a... ink for processing liquid ink jet head, 29b...ink jet head), 391...IR heater, 49...platen heater, 59...heating heater, 69...cooling fan, 79...preheater, 89...ventilation fan, 99...carriage, 119...platen, 129...cartridge, 139...carriage movement mechanism, 149...conveyance means, CONT...control unit, MS...main scanning direction, SS...sub-scanning direction, M...recording medium, 100...recording device, 200...host device, 210...printer driver, 230...communication control unit, 240...monitor, 300...printer unit, 400...printer control unit, 1... Body case, 2...feeding section, 9...carriage housing, 12...carriage main body, 13...carriage movement mechanism, 14...transport means, 21...feeding shaft, 3...printing chamber, 30, 11...platen, 31...recording unit, 32...carriage, 33...support plate, 34...treatment liquid inkjet head, 35...ink inkjet head, 37...X-axis guide rail, 38...suction section, 39...heater, 4...drying section, 5...winding section, 51...winding shaft, 6...base, 71-77...rollers, 8...cartridge mounting section, 81...treatment liquid cartridge, 82...ink cartridge, R1, R2...roll, S...sheet

Claims

1. a treatment liquid application step of ejecting the treatment liquid from an inkjet head and applying it to the recording medium; a first ink deposition step of ejecting the first ink composition from an inkjet head and depositing it on a recording medium; a second ink deposition step of ejecting the second ink composition from an inkjet head and depositing it on a recording medium, the treatment liquid is an aqueous treatment liquid containing a flocculant, the first ink composition and the second ink composition are water-based ink compositions containing a coloring material, In a scanning operation in which the relative positions of the inkjet head and the recording medium are moved, the treatment liquid, the first ink composition, and the second ink composition are deposited on the recording medium in the same scanning operation for the same scanning region; the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the first ink composition land on the recording medium is 0.15 seconds or more and 0.25 seconds or less; the time from when the droplets of the treatment liquid land on the recording medium to when the ink droplets of the second ink composition land on the recording medium is 0.3 seconds or more and 0.6 seconds or less; the treatment liquid contains a silicone surfactant, The silicone surfactant includes a silicone surfactant a, The silicone surfactant a is a silicone surfactant in which a 0.1% by mass aqueous solution of the surfactant has a surface tension of 28.0 mN / m or less, and a 0.1% by mass propylene glycol solution of the surfactant has a surface tension of 28.0 mN / m or less.

2. In claim 1, A recording method, wherein the content of the silicone surfactant a in the treatment liquid is 0.1% by mass or more and 1.5% by mass or less.

3. In claim 1, a recording method in which the first ink composition and the second ink composition each exhibit a 5-fold or greater increase in viscosity when mixed with a 7% by mass aqueous solution of calcium formate in a mass ratio (ink composition:aqueous solution) of 10:

1.

4. In claim 1, The recording method, wherein the droplets of the treatment liquid have a mass of 1 ng or more and 7.0 ng or less.

5. In claim 1, A recording method, wherein the surface temperature of the recording medium in the treatment liquid application step, the first ink application step, and the second ink application step is 45° C. or less.

6. In claim 1, The silicone surfactant a is a silicone surfactant having a maximum peak in the molecular weight range of 300 or more in the molecular weight range of 1500 to 4500 in the molecular weight distribution measured by gel permeation chromatography.

7. In claim 1, A recording method, wherein the time difference between when the droplets of the first ink composition land on the recording medium and when the droplets of the second ink composition land on the recording medium is 0.1 seconds or more and 0.5 seconds or less.

8. In claim 1, The treatment liquid contains an organic solvent that is a polyol having a normal boiling point of 170°C or more and 240°C or less. Contains, recording method.

9. In claim 1, The recording method, wherein the processing liquid does not contain more than 5% by mass of a nitrogen-containing solvent.

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

11. 10. A recording method according to claim 1, wherein: An ink set comprising the treatment liquid, the first ink composition, and the second ink composition.

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