Ink set, recording apparatus, and recording method

Abstract

The present application provides an ink set, a recording device, and a recording method, which can achieve excellent quality (ink absorption and granularity) and rubbing resistance in both low-permeability substrates and non-permeability substrates. An ink set according to an embodiment of the present application includes an aqueous ink composition containing a colorant, a first treatment liquid containing a coagulant, and a second treatment liquid containing a coagulant. The coagulant in the first treatment liquid has a content of 0.60 mol / kg or more, and the coagulant in the second treatment liquid has a content of less than 0.60 mol / kg. The first treatment liquid is used together with the ink composition to record on a recording medium that is a low-permeability substrate, and the second treatment liquid is used together with the ink composition to record on a recording medium that is a non-permeability substrate.

Description

Technical Field

[0001] This invention relates to an ink set, a recording device, and a recording method. Background Technology

[0002] Inkjet recording methods can record high-definition images using relatively simple devices, and have made rapid progress in various aspects. Among them, extensive research has been conducted on obtaining high-quality images.

[0003] For example, Patent Document 1 discloses a recording method comprising a step of attaching a reaction liquid and a coloring ink composition to a recording medium such as coated paper, wherein the reaction liquid contains a coagulant that coagulates the components of the coloring ink composition, and the coloring ink composition contains a pigment and a resin.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-064640 Summary of the Invention

[0007] However, there are differences in image quality (especially ink adhesion and graininess) and abrasion resistance between recordings on low-permeability substrates such as coated paper and recordings on non-permeability substrates such as membranes. In other words, it is difficult to obtain excellent image quality (ink adhesion and graininess) and abrasion resistance in recordings on both low-permeability and non-permeability substrates.

[0008] One aspect of the ink group involved in this invention includes:

[0009] A water-based ink composition containing pigments, a first treatment liquid containing a coagulant, and a second treatment liquid containing a coagulant.

[0010] The coagulant content of the first treatment solution is above 0.60 mol / kg.

[0011] The coagulant content of the second treatment solution is less than 0.60 mol / kg.

[0012] The first processing liquid, together with the ink composition, is used to record onto a recording medium that serves as a low-permeability substrate.

[0013] The second processing liquid, together with the ink composition, is used to record onto a recording medium that serves as a non-permeable substrate.

[0014] One aspect of the recording device according to the present invention is to record to a recording medium.

[0015] The recording device includes an ink group as described above.

[0016] The recording device performs:

[0017] A first recording is performed using the ink composition and the first processing liquid on a recording medium that serves as a low-permeability substrate; and

[0018] The ink composition and the second processing liquid are used to record a second record on a recording medium that serves as a non-permeable substrate.

[0019] One aspect of the recording method according to the present invention uses the ink group of the above-described aspect to record to a recording medium.

[0020] The recording method includes the following steps:

[0021] Select the processing solution for recording from the first processing solution and the second processing solution;

[0022] The selected treatment solution is applied to the recording medium; and

[0023] The ink composition is then applied to the recording medium.

[0024] The recording method is any one of the following: a first record in which the selected processing liquid is the first processing liquid and the recording medium is a low-permeability substrate; or a second record in which the selected processing liquid is the second processing liquid and the recording medium is a non-permeable substrate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating the change in ultrasonic transmission intensity over time on low-permeability substrates, non-permeable substrates, and permeable substrates.

[0026] Figure 2 This is a schematic diagram of an example of an inkjet recording device according to an embodiment.

[0027] Figure 3 This is a schematic diagram of the carriage periphery of an example of an inkjet recording apparatus according to an embodiment.

[0028] Figure 4 This is a block diagram of an example of an inkjet recording device according to an embodiment.

[0029] Figure 5 It is a diagram that schematically illustrates a regular pattern.

[0030] Explanation of reference numerals in the attached figures

[0031] 1: Inkjet recording device; 2: Inkjet head; 3: IR heater; 4: Platen heater; 5: Heating heater; 6: Cooling fan; 7: Preheater; 8: Ventilation fan; 9: Carrier; 11: Platen; 12: Ink cartridge; 13: Carrier moving mechanism; 14: Transport unit; 101: Interface section; 102: CPU; 103: Memory; 104: Unit control circuit; 111: Transport unit; 112: Carrier unit; 113: Head unit; 114: Drying unit; 121: Detector group; 130: Computer; CONT: Control unit; MS: Main scanning direction; SS: Sub-scanning direction; M: Recording medium. Detailed Implementation

[0032] The embodiments of the present invention will now be described. These embodiments are used to illustrate examples of the present invention. The present invention is not limited to these embodiments in any way, and includes various modifications implemented without altering the spirit of the invention. It should be noted that not all of the configurations described below are essential components of the present invention.

[0033] 1. Ink group

[0034] An embodiment of the present invention relates to an ink assembly comprising an aqueous ink composition containing pigments, a first processing liquid containing a coagulant, and a second processing liquid containing a coagulant. The first processing liquid contains 0.60 mol / kg or more of the coagulant, and the second processing liquid contains less than 0.60 mol / kg of the coagulant. The first processing liquid and the ink composition are used together to record on a recording medium that is a low-permeability substrate, and the second processing liquid and the ink composition are used together to record on a recording medium that is a non-permeable substrate.

[0035] When recording on low-permeability substrates such as coated paper or non-permeable substrates such as films, although both are similar recording media in terms of their difficulty in absorbing liquids, differences in quality arise, and neither yields excellent image quality and abrasion resistance. Recently, a detailed study on the liquid permeability of low-permeability substrates revealed that, after a certain period of time following a droplet drop, the liquid permeability tends to increase compared to substrates such as ordinary paper. In other words, this quality difference is because, in recording media on low-permeability substrates, the increased permeability of the processing liquid over time leads to incomplete reaction between the processing liquid and the ink. Therefore, it is determined that for recording on low-permeability substrates, a higher reactivity between the ink and the processing liquid is needed. On the other hand, in recording on non-permeable substrates, if the reactivity between the ink and the processing liquid is too high, image quality, such as graininess, and abrasion resistance will deteriorate; therefore, it is necessary to control the reactivity to the minimum required level.

[0036] In controlling reactivity, one approach is to vary the amount of processing liquid adhering to the coating. However, with a low amount of processing liquid, it's difficult to achieve uniform adhesion, especially during inkjet coating where droplets become sparse, potentially preventing contact between the processing liquid and ink droplets. Conversely, a high amount of processing liquid can reduce drying efficiency and potentially worsen abrasion resistance due to increased liquid adhesion.

[0037] Therefore, the inventors conducted in-depth research and achieved the following configuration: preparing a treatment solution with a high concentration of coagulant and a treatment solution with a low concentration of coagulant, and selecting the treatment solution according to the recording medium to be recorded. As a result, excellent image quality (ink adhesion and graininess) and abrasion resistance can be obtained in recordings on both low-permeability and non-permeability substrates.

[0038] In this invention, "ink set" refers to two or more inks (including processing liquid) used in a recording device. The ink set, including at least the ink composition, the first processing liquid, and the second processing liquid, can be stored separately in individual ink containers or in different chambers of a single-piece ink container. It should be noted that the various inks in the ink set are preferably used for inkjet printing via inkjet technology.

[0039] The ink group involved in this embodiment includes at least one ink composition, at least one first processing liquid, and at least one second processing liquid. At least one of the ink composition, the first processing liquid, and the second processing liquid may be present in two or more forms.

[0040] 1.1 Recording Media

[0041] In the ink group according to this embodiment, the first processing liquid and the ink composition are used together to record to a recording medium that is a low-permeability substrate, and the second processing liquid and the ink composition are used together to record to a recording medium that is a non-permeable substrate.

[0042] The preferred low-permeability substrate satisfies the following formula (1) when the permeability of water dropped onto the low-permeability substrate for 60 seconds is set as A, while the non-permeable substrate does not satisfy the following formula (1) when the permeability of water dropped onto the non-permeable substrate for 60 seconds is set as A. As a result, there is a tendency to obtain better image quality (ink adhesion and graininess) and abrasion resistance.

[0043] 10log 10 (A / A0)<-5[dB]···Equation (1)

[0044] (A0: Permeability of water after 60 seconds on the reference substrate; A: Permeability of water after 60 seconds on the target substrate.)

[0045] The dynamic permeability in equation (1) above can be measured by measuring ultrasonic transmission, which is the permeability of water to the substrate. For example, when the substrate softens as it absorbs liquid, the ultrasonic transmission intensity decreases. Therefore, the permeability of the liquid at a certain time can be measured by immersing the substrate in a measuring tank and measuring the change in the ultrasonic transmission signal.

[0046] It should be noted that permeability can be measured using instruments such as the dynamic permeability tester DPM33 and DPM30 (manufactured by emco).

[0047] Figure 1 This is a schematic diagram illustrating the change over time in ultrasonic transmission intensity on low-permeability, non-permeable, and permeable substrates. For example, as shown... Figure 1 As shown, the ultrasonic wave transmission intensity (permeability) on a non-permeable substrate tends to remain constant regardless of the time elapsed. On the other hand, for example, as... Figure 1 As shown, the ultrasonic transmission intensity (permeability) on low-permeability substrates tends to be temporarily lower after the droplet falls, but increases after a certain period of time (low-permeability substrate A), or increases immediately after the droplet falls (low-permeability substrate B).

[0048] Furthermore, it is generally believed that substrates such as ordinary paper (permeable substrates) have higher permeability than low-permeability substrates, but... Figure 1 The results show that if a droplet has been in place for a relatively long time, the permeability of the low-permeability substrate tends to be higher than that of ordinary paper and other substrates. This indicates that in recording media using low-permeability substrates, the permeability of the processing liquid increases over time, and the reactivity of the processing liquid with the ink may sometimes be less complete compared to ordinary paper and other substrates.

[0049] In formula (1) above, the reference substrate is preferably a non-permeable substrate, more preferably a polyethylene terephthalate film. For example, "PET50A" can be used as such a reference substrate.

[0050] 10log of the above formula (1) in low-permeability substrate 10 The (A / A0) value is below -5 dB, more preferably below -7 dB, even more preferably below -8 dB, even more preferably -8.5 dB, and particularly preferably below -9 dB. The lower limit is not limited, but is preferably above -20 dB.

[0051] 10log of the above formula (1) in a non-permeable substrate 10The (A / A0) value is -5 [dB] or more, more preferably -3 [dB] or more, even more preferably -1 [dB] or more, and particularly preferably 0 [dB].

[0052] 10log of the above formula (1) in the permeable substrate 10 The (A / A0) value is preferably less than -5 [dB] and more than -9 [dB], more preferably less than -5 [dB] and more than -8 [dB], and even more preferably less than -5 [dB] and more than -7 [dB].

[0053] In a low-permeability substrate, the value of formula (1) above, measured 10log after 60 seconds of water addition, is taken as the value measured 10 seconds later. 10 The (A / A0) value is preferably below 0 dB, more preferably below -0.5 dB, and even more preferably below -1 dB. The lower limit value is preferably above -4 dB, more preferably above -3 dB, and even more preferably above -2 dB.

[0054] In a non-permeable substrate, the value of equation (1) above, measured 10log after 60 seconds of water addition, is taken as the value measured 10 seconds later. 10 The (A / A0) value is preferably greater than -1 [dB], more preferably greater than -0.5 [dB], and particularly preferably 0 [dB].

[0055] In a permeable substrate, the value of formula (1) above, measured 10log after 60 seconds of water addition, is taken as the value measured 10 seconds later. 10 The (A / A0) value is preferably below -1 dB, more preferably below -2 dB, even more preferably below -3 dB, and particularly preferably below -4 dB. The lower limit is not limited, but is preferably above -10 dB.

[0056] It should be noted that the low-permeability substrate or non-permeability substrate is preferably a low-absorbency substrate or non-absorbent substrate that has low or no water absorption of liquids such as inks and processing liquids. Quantitatively speaking, a low-absorbency substrate or non-absorbent substrate refers to a substrate that, in the Bristow process, from the start of contact to 30 msec... 1 / 2 The water absorption rate up to this point is 10 mL / m 2 The following substrates. The Brinell method is the most widely used method for determining liquid absorption over a short period of time, and it is also used by the Japan Pulp Technology Association (JAPAN TAPPI). For details of the test method, please refer to Specification No. 51 "Paper and Paperboard - Liquid Absorption Test Method - Brinell Method" in "JAPAN TAPPI Pulp Test Methods 2000 Edition".

[0057] In contrast, the preferred permeable substrate is prepared in the Bristow process from the start of contact to 30 msec.1 / 2 The water absorption rate up to 10 mL / m 2 A water-absorbing substrate.

[0058] 1.1.1 Low-permeability substrate

[0059] As a low-permeability substrate, it is preferable to have a substrate that satisfies the above formula (1) and includes a support and a coating layer on at least one side of the support. For example, as a substrate with a paper support, examples include: coated paper, coated paper, matte paper and other printing base paper. When the support is a plastic film, examples include: articles in which a hydrophilic polymer is formed as a coating layer on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene and the like, and articles in which particles such as silica and titanium are formed together with an adhesive to form a coating layer.

[0060] [Support]

[0061] As a support, there are no particular restrictions; examples include paper primarily composed of wood fibers, and sheet-like materials primarily composed of wood fibers and synthetic fibers. As for paper, there are no particular restrictions; examples include wood pulp and waste paper pulp.

[0062] The support may contain fillers. White pigments, described later, are used as fillers.

[0063] Internal sizing agents can be used when fabricating the support structure. Examples of internal sizing agents include: neutral rosin-based sizing agents used in neutral papermaking, alkenyl succinic anhydride (ASA), alkyl ketene dimers (AKD), and petroleum resin-based sizing agents.

[0064] [Coating]

[0065] The coating contains pigment particles and binders. It may also contain other components such as cationic compounds and surfactants, depending on the requirements.

[0066] (pigment particles)

[0067] As pigment particles, inorganic particles can be used, or a combination of inorganic and organic particles can be used.

[0068] Examples of inorganic particles include: kaolin, talc, heavy calcium carbonate, light calcium carbonate, calcium sulfite, amorphous silicon dioxide, titanium dioxide, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, chlorite, etc.

[0069] Examples of organic particles include water-soluble dispersions such as styrene-acrylic acid copolymer particles, styrene-butadiene copolymer particles, polystyrene particles, and polyethylene particles. These organic particles can be used alone or in combination of two or more.

[0070] The amount of organic particles added is preferably 2 to 20% by mass relative to the total mass of pigment particles in the coating layer. The volume average particle size (D50) of the organic particles is preferably 0.2 to 3.0 μm.

[0071] (Adhesive)

[0072] As an adhesive, a water-based resin is preferred. As such a water-based resin, the same substance as the resin particles contained in the ink composition described later can be used.

[0073] The amount of water-based resin added is preferably 2 to 100% by mass relative to the total mass of pigment particles in the coating layer, more preferably 3 to 50% by mass.

[0074] (Catonic compounds)

[0075] The coating layer may contain a cationic compound. Cationic compounds such as cationic resins (cationic polymers), cationic surfactants, etc., are possible, with cationic resins being more preferred. The same cationic compound that may be contained in the first treatment liquid described later can be used as such a cationic compound.

[0076] The preferred dry adhesion amount of the cationic compound is 0.3 g / m. 2 Above and 2.0g / m 2 the following.

[0077] (surfactant)

[0078] As a surfactant, the same substance as the surfactant contained in the ink composition described later can be used.

[0079] The amount of surfactant added is preferably 10% by mass or less, more preferably 1% by mass or less, relative to the total mass of the cationic compound. The lower limit is not particularly limited, but is preferably 0.1% by mass or more.

[0080] (Other ingredients)

[0081] Other components include, for example, alumina powder, pH adjusters, preservatives, antioxidants, and other additives.

[0082] (Formation method)

[0083] The coating layer can be formed, for example, by impregnating or applying a coating liquid onto a support. There are no particular limitations on the impregnation or application methods for the coating liquid; examples include: coating using various coating machines such as conventional sizing machines, horizontal roller sizing machines, film transfer sizing machines, doctor blade coaters, bar coaters, air knife coaters, and curtain coaters; and impregnation or adhesion using conventional sizing machines, horizontal roller sizing machines, film transfer sizing machines, followed by on-machine finishing.

[0084] The preferred amount of coating liquid, based on solid content, is 0.5 g / m³. 2 Above and 20g / m 2 Below, 1g / m is preferred. 2 Above and 15g / m 2 the following.

[0085] After impregnation or coating, drying can be carried out as needed, preferably at a temperature of 100°C or higher and 250°C or lower.

[0086] The low-permeability substrate can further form a back layer on the reverse side of the support, and other layers can be formed between the support and the coating layer and between the support and the back layer. A protective layer can also be provided on the coating layer. These layers can be single layers or multiple layers.

[0087] 1.1.2 Non-permeable substrate

[0088] As a non-permeable substrate, examples include substrates that do not satisfy the above formula (1), and preferably have a recording surface composed of plastic, more preferably have a recording surface composed of plastic. The surface of the recording surface does not have an absorbent layer or a receiving layer for absorbing liquid. Examples include: substrates coated with plastic on a paper or other substrate, substrates with a plastic film bonded to a paper or other substrate, and plastic films without an absorbent layer or a receiving layer. Examples of plastics mentioned herein include: polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc.

[0089] 1.1.3 Permeable Substrate

[0090] As a permeable substrate, as described above, 10log of the above formula (1) 10 The (A / A0) value is preferably below -5 dB and above -9 dB, more preferably below -5 dB and above -8 dB, and even more preferably below -5 dB and above -7 dB. Furthermore, the permeability substrate is preferably determined in the Bristow process from the start of contact to 30 msec. 1 / 2 The water absorption rate up to 10 mL / m 2 A water-absorbing substrate.

[0091] Specific examples of permeable substrates include: ordinary paper, recycled paper, high-grade paper, special paper for inkjet recording, and cloth.

[0092] The first processing liquid in the ink group according to this embodiment can be further used together with the ink composition to record onto a recording medium that is a permeable substrate. According to the ink group according to this embodiment, excellent image quality (ink adhesion and graininess, etc.) and abrasion resistance can be obtained even on a permeable substrate.

[0093] Hereinafter, the first processing liquid, the second processing liquid, and the various components contained in the ink composition of the ink group involved in this embodiment will be described.

[0094] 1.2 First treatment liquid

[0095] The ink assembly of this embodiment includes a first processing liquid containing a coagulant at a content of 0.60 mol / kg or more, which is used together with the ink composition to record onto a recording medium that is a low-permeability substrate.

[0096] Recent findings indicate that in recording media with low permeability substrates, the permeability of the processing solution increases over time, leading to insufficient reaction between the processing solution and the ink. Therefore, the first processing solution is formulated in a form where the ink composition has higher reactivity with the processing solution, i.e., a coagulant content of 0.60 mol / kg or higher.

[0097] 1.2.1 Coagulant

[0098] The ink assembly according to this embodiment includes a first processing liquid containing a coagulant. The coagulant reacts with components such as pigments and resins contained in the ink composition to coagulate the components of the ink composition. Furthermore, the coagulant can also react with white pigments contained in the white ink composition (described later) and resins contained in the transparent ink composition (described later) to coagulate the components of the white ink composition and the transparent ink composition. Such coagulation, for example, can improve the color development of the pigments and / or improve the adhesion of the resin particles.

[0099] The coagulant content in the first treatment solution is 0.60 mol / kg or more, preferably 0.65 mol / kg or more, more preferably 0.70 mol / kg or more, even more preferably 0.75 mol / kg or more, and particularly preferably 0.80 mol / kg or more. At this coagulant content, the image quality tends to be more refined, with improved reactivity, better ink adhesion, and finer grain.

[0100] In addition, the upper limit of the coagulant content in the first treatment liquid is not particularly limited, but is preferably 1.5 mol / kg or less, more preferably 1.2 mol / kg or less, even more preferably 1.0 mol / kg or less, and particularly preferably 0.9 mol / kg or less.

[0101] It should be noted that the content of coagulant [mol / kg] in this invention refers to the number of moles of coagulant relative to the total mass [kg] of the treated liquid.

[0102] As a coagulant, it is not particularly limited and can include: metal salts, acids, cationic compounds, etc. As a cationic compound, cationic resins (cationic polymers), cationic surfactants, etc., can be used. Among these, polyvalent metal salts are preferred as metal salts, and cationic resins are preferred as cationic compounds. As an acid, examples include: organic acids and inorganic acids, with organic acids being preferred.

[0103] Therefore, cationic resins, organic acids, and polyvalent metal salts are preferred as coagulants for achieving superior image quality and abrasion resistance.

[0104] In particular, polyvalent metal salts are preferred as coagulants for achieving superior image quality and abrasion resistance.

[0105] (Polyvalent metal salts)

[0106] 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 these metal ions constituting polyvalent metal salts, calcium ions and magnesium ions are preferred from the perspective of excellent cohesiveness of ink components.

[0107] The anions constituting the polyvalent metal salts are either inorganic or organic ions. That is, the polyvalent metal salts in this invention are composed of inorganic or organic ions and a polyvalent metal. Examples of such inorganic ions include: chloride ions, perchlorate ions, bromide ions, iodide ions, nitrate ions, nitrite ions, sulfate ions, permanganate ions, cyanide ions, chromate ions, tungstate ions, arsenate ions, hexafluorosilicate ions, molybdate ions, phosphate ions, and hydroxide ions. Examples of organic ions include: organic acid ions, such as: carboxylic acid ions, formic acid ions, acetate ions, lactate ions, propionic acid ions, ascorbic acid ions, and oxalate ions.

[0108] Specific examples of the aforementioned polyvalent metal salts include: calcium nitrate tetrahydrate, calcium chlorate, calcium perchlorate, calcium permanganate, calcium bromide, calcium formate, calcium nitrite, calcium chloride, calcium acetate, calcium cyanide, L-calcium lactate pentahydrate, calcium propionate, calcium ascorbate dihydrate, calcium iodide, calcium chromate, calcium oxalate, calcium hydroxide, calcium tungstate, calcium carbonate, calcium arsenate, calcium hexafluorosilicate, calcium molybdate, calcium iodate, calcium sulfate dihydrate, tricalcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, magnesium sulfate, magnesium chloride, magnesium carbonate, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, magnesium silicate, copper nitrate, magnesium acetate, aluminum acetate, etc.

[0109] These polyvalent metal salts can be used alone or in combination of two or more. It should be noted that these metal salts may contain water in their raw material form.

[0110] As metal salts other than polyvalent metal salts, examples include: sodium salts, potassium salts, etc.; monovalent metal salts include: sodium sulfate, potassium sulfate, etc.

[0111] (Organic acids)

[0112] Examples of organic acids include, for example, 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, phosphoric acid, pyrrolidone carboxylic acid, pyranone carboxylic acid, pyrrolic carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophenecarboxylic acid, nicotinic acid, or derivatives of these compounds, or their salts. An organic acid can be used alone or in combination with two or more. Metal salts of organic acids are also included in the above-mentioned metal salts. The same applies to the salts of organic acids.

[0113] Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. Inorganic acids can be used alone or in combination of two or more.

[0114] (Catonic resin)

[0115] Examples of cationic resins (cationic polymers) include: cationic urethane resins, cationic olefin resins, cationic amine resins, and cationic surfactants. Water-soluble cationic polymers are preferred.

[0116] As cationic urethane resins, commercially available products can be used, such as: HYDRAN CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, CP-7610 (trade name, manufactured by Dai Nippon Ink Chemical Industry Co., Ltd.), SUPERFLEX 600, 610, 620, 630, 640, 650 (trade name, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), URETHANE EMULSION WBR-2120C, WBR-2122C (trade name, manufactured by Taisei Fine Chemical Co., Ltd.), etc.

[0117] Cationic olefin resins have olefins such as ethylene and propylene in their structural backbone, and well-known materials can be appropriately selected. Furthermore, cationic olefin resins can be in an emulsion state dispersed in solvents including water and organic solvents. Commercially available products can be used as cationic olefin resins, such as ARROWBASE CB-1200 and CD-1200 (trade name, manufactured by UNITIKA Co., Ltd.).

[0118] As cationic amine resins (cationic polymers), any resin containing an amino group in its structure can be appropriately selected from known materials. Examples include polyamine resins, polyamide resins, and polyallylamine resins. Polyamine resins are resins whose main backbone contains amino groups. Polyamide resins are resins whose main backbone contains amide groups. Polyallylamine resins are resins whose main backbone contains structures derived from allyl groups.

[0119] Examples of cationic surfactants include: primary, secondary and tertiary amine salts, alkylamine salts, dialkylamine salts, aliphatic amine salts, benzalkonium chloride salts, quaternary ammonium salts, etc.

[0120] A single coagulant can be used alone, or two or more can be used in combination.

[0121] The coagulant in the first processing solution preferably has a solubility of 100g or more in 100g of water at 20°C. Coagulants with such solubility are highly water-soluble, and therefore dissolve well in the first processing solution even at high concentrations. As a result, the reactivity of the first processing solution is improved, leading to better image quality and abrasion resistance. It should be noted that highly water-soluble coagulants are prone to hygroscopicity, which can sometimes reduce the abrasion resistance of the recorded material. However, the low-permeability substrate to which the first processing solution is used is less prone to abrasion resistance reduction due to moisture absorption; therefore, the reduction in abrasion resistance can be suppressed, resulting in both good image quality and abrasion resistance.

[0122] The solubility is preferably 110g or more, more preferably 120g or more. The upper limit of the solubility is not particularly limited; for example, it is preferably 400g or less, more preferably 300g or less, even more preferably 200g or less, particularly preferably 150g or less, and even more particularly preferably 140g or less.

[0123] Examples of coagulants that have a solubility of 100g or more in 100g of water at 20°C include: calcium nitrate tetrahydrate (129g / 100g water), calcium chlorate (209g / 100g water), calcium perchlorate (188g / 100g water), calcium permanganate (338g / 100g water), and calcium bromide (143g / 100g water). Preferably, the coagulant is selected from one or more of calcium nitrate tetrahydrate and calcium bromide, and more preferably from calcium nitrate tetrahydrate.

[0124] 1.2.2 Water

[0125] The first processing liquid in the ink assembly according to this embodiment is preferably an aqueous composition containing at least water as a solvent component of the composition. In the liquid medium component, the water content is preferably 30-100% by mass, more preferably 40-90% by mass, and even more preferably 50-80% by mass. It should be noted that the liquid medium refers to solvent components such as water and organic solvents.

[0126] The water content relative to 100% by mass of the first treatment liquid is preferably 20% by mass or more, more preferably 30 to 99% by mass, even more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass.

[0127] As the water source, pure or ultrapure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, or distilled water, is preferred. In particular, water that has been treated with ultraviolet light or sterilized by adding hydrogen peroxide can inhibit the growth of mold and bacteria for a long period of time, and is therefore preferred.

[0128] 1.2.3 Organic solvents

[0129] The first processing liquid in the ink assembly according to this embodiment may also contain an organic solvent as a solvent component of the composition. In the liquid medium component, the content of the organic solvent is preferably 5-50% by mass, more preferably 15-45% by mass, and even more preferably 25-40% by mass. It should be noted that the liquid medium refers to solvent components such as water and organic solvents.

[0130] The content of the organic solvent relative to the total mass of the first treatment liquid is preferably 1% by mass or more, more preferably 5% by mass or more, further preferably 10% by mass or more, even more preferably 15% by mass or more, particularly preferably 20% by mass or more, and even more preferably 25% by mass or more. The upper limit is preferably 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 35% by mass or less. Furthermore, the content of the organic solvent is also preferably set within the above-mentioned range relative to the total mass of the liquid medium components contained in the first treatment liquid.

[0131] Examples of organic solvents include esters, alkylene glycol ethers, cyclic esters, nitrogen-containing solvents, alcohols, and polyols. Examples of nitrogen-containing solvents include cyclic amides and non-cyclic amides. Examples of non-cyclic amides include alkoxyalkylamides.

[0132] Examples of esters include: ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, and other glycol monoacetates; and ethylene glycol diacetates, diethylene glycol diacetate, and other glycol diesters.

[0133] As alkylene glycol ethers, any mono- or di-ether of an alkylene glycol is acceptable, with alkyl ethers being preferred. Specific examples include: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, etc., and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, etc.

[0134] Examples of cyclic esters include cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone, as well as compounds in which the hydrogen atom of the methylene group adjacent to their carbonyl group is replaced by an alkyl group having 1 to 4 carbon atoms.

[0135] Examples of alkoxyalkylamides include 3-methoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, and 3-methoxy-N,N-methylethylpropionamide.

[0136] Examples of cyclic amides include lactams, such as 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, 1-butyl-2-pyrrolidone, and other pyrrolidone derivatives. These substances are preferred for promoting resin film formation, and 2-pyrrolidone is particularly preferred.

[0137] Examples of alcohols include compounds in which one hydrogen atom of an alkane is replaced by a hydroxyl group. Preferably, the alkane has 10 or fewer carbon atoms, more preferably 6 or fewer, and even more preferably 3 or fewer. The alkane has 1 or more carbon atoms, preferably 2 or more. Alkanes can be straight-chain or branched. Examples of alcohols include methanol, ethanol, n-propanol, and isopropanol.

[0138] Polyols have two or more hydroxyl groups in their molecules. Examples of polyols include alkanediols and polyols in general.

[0139] Alkanediols can be exemplified by compounds in which alkanes are substituted with two hydroxyl groups. Examples of alkanediols include: ethylene glycol (also known as ethane-1,2-diol), propylene glycol (also known as propane-1,2-diol), 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,3-propanediol, 1,3-butanediol (also known as 1,3-Butanediol), 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, etc. Diols, 2,4-pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, etc.

[0140] Examples of polyols include condensates of two or more alkanediols formed by intermolecular condensation of molecules through hydroxyl groups, and compounds having three or more hydroxyl groups.

[0141] Examples of condensates formed by the intermolecular condensation of two or more molecules of alkyl glycols through hydroxyl groups include: dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as triethylene glycol and tripropylene glycol.

[0142] Compounds having three or more hydroxyl groups are compounds with three or more hydroxyl groups as their backbone, which are based on alkane or polyether structures. Examples of compounds having three or more hydroxyl groups include: glycerol, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, polyoxypropylene triol, etc.

[0143] The content of polyols relative to the total mass of the first treatment liquid is preferably 1-65% by mass, more preferably 5-60% by mass, more preferably 10-50% by mass, even more preferably 15-50% by mass, and particularly preferably 20-40% by mass. The content of alkanediols and / or polyols may also be within the above range.

[0144] The above-mentioned organic solvents can be used alone or in combination of two or more.

[0145] 1.2.4 Surfactants

[0146] The first processing liquid in the ink assembly according to this embodiment may also contain a surfactant. The surfactant has the function of reducing the surface tension of the first processing liquid and improving its wettability with the recording medium. Among surfactants, acetylenic diol surfactants, silicone surfactants, and fluorinated surfactants are preferred.

[0147] As acetylenic diol surfactants, they are not particularly limited, and examples 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, DF110D (all trade names, manufactured by Air Products & Chemicals), 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 Industries), ACETYLENOL E00, E00P, E40, E100 (all trade names, manufactured by Kawaken Fine Chemical Co., Ltd.)

[0148] As an organosilicon surfactant, without particular limitation, polysiloxane compounds are preferably listed. As such polysiloxane compounds, without particular limitation, examples include, for instance, polyether-modified organosilicon compounds. Commercially available products of this polyether-modified organosiloxane include, for example: BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (trade names, manufactured by BYK-Chemie Japan), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (trade names, manufactured by Shin-Etsu Chemical Industry Co., Ltd.), SILFACE. SAG002, 005, 503A, 008 (the above are trade names, manufactured by Nisshin Chemical Industry Co., Ltd.), etc.

[0149] As fluorinated surfactants, fluorinated modified polymers are preferred. Specific examples include: BYK-3440 (manufactured by BYK-Chemie, Japan), SURFRON S-241, S-242, S-243 (trade names, manufactured by AGC SEIMICHEMICAL), FTERGENT 215M (manufactured by Neos), etc.

[0150] The surfactants mentioned above can be used alone or in combination of two or more.

[0151] When the first treatment solution contains a surfactant, the surfactant content relative to the total mass of the first treatment solution is preferably 0.1% by mass or more and 2% by mass or less, more preferably 0.4% by mass or more and 1.5% by mass or less, and even more preferably 0.5% by mass or more and 1.0% by mass or less.

[0152] 1.2.5 Amines

[0153] The first processing liquid in the ink assembly according to this embodiment may also contain amines. Alkaneol amines are preferred. Examples of alkaneol amines include ethanolamine, propanolamine, triethanolamine, diethanolamine, and triisopropanolamine. These are sometimes also used as pH adjusters.

[0154] When the first treatment solution contains amines, the amine content relative to the total mass of the first treatment solution is preferably 0.01% by mass or more and 1.00% by mass or less, more preferably 0.03% by mass or more and 0.50% by mass or less, and even more preferably 0.05% by mass or more and 0.10% by mass or less.

[0155] 1.2.6 Other ingredients

[0156] The first processing liquid in the ink group involved in this embodiment may further contain urea, sugar, preservatives and mildew inhibitors, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, and other components as needed.

[0157] 1.3 Second treatment liquid

[0158] The ink assembly of this embodiment includes a second processing liquid containing a coagulant at a content of less than 0.60 mol / kg. The second processing liquid, together with the ink composition, is used to record onto a recording medium that is a non-permeable substrate.

[0159] When recording on non-permeable substrates, excessive reactivity between the ink and the processing liquid can lead to deterioration in image quality, such as graininess, and abrasion resistance. Therefore, the second processing liquid is formulated to achieve the minimum required reactivity between the ink composition and the processing liquid, i.e., a coagulant content of less than 0.60 mol / kg.

[0160] 1.3.1 Coagulant

[0161] The second processing liquid in the ink assembly described in this embodiment contains a coagulant.

[0162] The coagulant content in the second treatment solution is less than 0.60 mol / kg, preferably less than 0.55 mol / kg, more preferably less than 0.50 mol / kg, even more preferably less than 0.45 mol / kg, and particularly preferably less than 0.40 mol / kg. If the coagulant content is as described above, excellent image quality, such as abrasion resistance and grain size, can be achieved.

[0163] Furthermore, the lower limit of the coagulant content in the second treatment liquid is not particularly limited, but is preferably 0.05 mol / kg or more, more preferably 0.10 mol / kg or more, and even more preferably 0.15 mol / kg or more. More preferably 0.20 mol / kg or more, and even more preferably 0.25 mol / kg or more.

[0164] The type of coagulant in the second treatment solution can be the same as that in the first treatment solution.

[0165] The coagulant contained in the second treatment solution preferably has a solubility of less than 100g in 100g of water at 20°C. In recordings on non-permeable substrates, moisture absorption may lead to a decrease in abrasion resistance. However, coagulants with the aforementioned solubility have low water solubility and are less prone to moisture absorption; therefore, even recordings on non-permeable substrates tend to maintain excellent abrasion resistance.

[0166] The aforementioned solubility is preferably less than 80g, more preferably less than 60g, even more preferably less than 40g, and particularly preferably less than 20g. The lower limit of the aforementioned solubility is not particularly limited; for example, it is preferably 5g or more, more preferably 10g or more.

[0167] Examples of coagulants with a solubility of less than 100g in 100g of water at 20°C include: calcium formate (16.6g / 100g water), calcium nitrite (84.5g / 100g water), calcium chloride (74.5g / 100g water), calcium acetate (34.7g / 100g water), calcium cyanide (45g / 100g water), L-calcium lactate pentahydrate (5g / 100g water), calcium propionate (10g / 100g water), calcium ascorbate dihydrate (50g / 100g water), and calcium iodide (66g / 100g water). Preferably, the coagulant is selected from one or more of calcium formate and calcium propionate, and more preferably calcium formate.

[0168] 1.3.2 Other components

[0169] In the second processing liquid of the ink assembly according to this embodiment, the components other than the coagulant can be the same as those in the first processing liquid. That is, the second processing liquid can contain water, organic solvents, surfactants, amines, and the types and contents of these components can be the same as those in the first processing liquid. The second processing liquid may also further contain urea, sugars, preservatives and fungicides, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, etc., as needed.

[0170] It should be noted that when the second treatment liquid contains amines, the content of amines relative to the total mass of the second treatment liquid is preferably 0.001% by mass or more and 0.100% by mass or less, more preferably 0.001% by mass or more and 0.030% by mass or less, and even more preferably 0.001% by mass or more and 0.010% by mass or less.

[0171] 1.4 Ink Composition

[0172] The ink group involved in this embodiment has an aqueous ink composition containing colorant.

[0173] In this invention, "water system" refers to a composition that contains at least water as the main liquid medium component in the composition.

[0174] In the liquid medium component contained in the composition, the water content is 20% by mass or more, preferably 30-100% by mass, more preferably 35-98% by mass, even more preferably 40-90% by mass, and even more preferably 50-80% by mass. It should be noted that the liquid medium refers to solvent components such as water and organic solvents. The water content relative to the total mass of the composition can be set within the above range (less than 100% by mass).

[0175] 1.4.1 Pigments

[0176] As a colorant, any of dyes and pigments can be used. Pigments are preferred because they are resistant to fading from light and gases. Images formed on recording media using pigments not only have excellent image quality but also exhibit superior water resistance, gas resistance, and optical rotation resistance, resulting in good preservation. This property is particularly significant when forming images on recording media that are low-permeability or non-permeable substrates.

[0177] As pigments, there are no particular limitations, and both inorganic and organic pigments can be listed. As inorganic pigments, in addition to titanium dioxide and iron oxide, carbon black manufactured by known methods such as the contact process, furnace process, and thermal process can also be used. On the other hand, as organic pigments, examples include: azo pigments, polycyclic pigments, nitro pigments, nitroso pigments, aniline black, etc. Examples of azo pigments include: azo lakes, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc. Examples of polycyclic pigments include: phthalocyanine pigments, perylene pigments, perylene ketone pigments, anthraquinone pigments, quinacrine pigments, etc.

[0178] Examples of pigments used in black inks include carbon black. Carbon black is not specifically limited to these, and examples include furnace black, lamp black, acetylene black, or channel black (CI Pigment Black 7), as well as commercially available products such as No. 2300, 900, MCF88, No. 20B, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA77, MA100, No. 2200B (all trade names, manufactured by Mitsubishi Chemical Corporation), COLOURBLACK FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, PRINTEX 35, U, V, 140U, SPECIAL BLACK 6, 5, 4A, 4, 250 (all trade names, manufactured by Degussa), CONDUCTEXSC, RAVEN, etc. 1255, 5750, 5250, 5000, 3500, 1255, 700, etc. (all of the above are product names, manufactured by Columbia Carbon), RGAL400R, 330R, 660R, MOGUL L, MONARCH 700, 800, 880, 900, 1000, 1100, 1300, 1400, ELFTEX 12, etc. (all of the above are product names, manufactured by Cabot Japan Co., Ltd.)

[0179] As pigments for white inks, there are no particular limitations, and examples include: CI Pigment White 6, 18, 21, titanium dioxide, zinc oxide, zinc sulfide, antimony oxide, magnesium oxide, and zirconium oxide—all white inorganic pigments. In addition to these white inorganic pigments, white organic pigments such as hollow resin particles and polymer particles can also be used.

[0180] As pigments used in yellow inks, there are no particular limitations, and examples 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, 180.

[0181] As pigments used in magenta inks, there are no particular limitations, and examples include: CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48(Ca), 48(Mn), 57(Ca), 57:1 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, or CI pigment violet 19, 23, 32, 33, 36, 38, 43, 50.

[0182] As pigments used in cyan inks, there are no particular limitations, and examples include: CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, 66, CI Vapor Blue 4, 60.

[0183] In addition, pigments used in colored inks other than magenta, cyan, and yellow are not particularly limited, and examples include: CI pigments green 7 and 10, CI pigments brown 3, 5, 25, and 26, and CI pigments orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, and 63.

[0184] As a pearlescent pigment, it is not particularly limited, and examples include: titanium dioxide covering mica, fish scale foil, bismuth oxychloride, and other pigments that have a pearly or interference luster.

[0185] As a metallic pigment, it is not particularly limited and can be composed of particles made of elements or alloys such as aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, and copper.

[0186] When using pigments as colorants, it is preferable to ensure that the pigments can be stably dispersed in water. Examples of methods include: dispersing the pigment in a resin dispersant such as a water-soluble resin and / or a water-dispersible resin (hereinafter, pigments treated by this method are sometimes referred to as "resin-dispersed pigments"); dispersing the pigment in a dispersant (hereinafter, pigments treated by this method are sometimes referred to as "dispersant-dispersed pigments"); and introducing hydrophilic functional groups onto the surface of pigment particles through chemical or physical means, enabling the pigment to be dispersed and / or dissolved in water without the use of the resin or dispersant (hereinafter, pigments treated by this method are sometimes referred to as "surface-treated pigments").

[0187] The ink composition can use any of the resin-dispersed pigments, dispersant-dispersed pigments, and surface-treated pigments, and can also be used in various mixed forms as needed, preferably containing resin-dispersed pigments.

[0188] Examples of resin dispersants used for dispersing pigments include: polyvinyl alcohols, polyacrylic acid, acrylic acid-acrylonitrile copolymers, vinyl acetate-acrylate copolymers, acrylic acid-acrylate copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylate copolymers, styrene-α-methylstyrene-acrylic acid copolymers, styrene-α-methylstyrene-acrylate-acrylate copolymers, styrene-maleic acid copolymers, styrene-maleic anhydride copolymers, vinylnaphthalene-acrylic acid copolymers, vinylnaphthalene-maleic acid copolymers, vinyl acetate-maleic ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and their salts. Among these, copolymers of monomers having hydrophobic functional groups and monomers having hydrophilic functional groups, and polymers composed of monomers possessing both hydrophobic and hydrophilic functional groups, are preferred. As a copolymer, it can be used in any form, such as a random copolymer, block copolymer, cross-linked copolymer, or graft copolymer.

[0189] The content ratio of the resin dispersant can be appropriately selected according to the pigment to be dispersed. It is preferably 5 parts by mass or more and 200 parts by mass or less, more preferably 30 parts by mass or more and 120 parts by mass or less, relative to the pigment content in the ink (100 parts by mass).

[0190] Acid dyes are preferred. Examples of acid dyes include: azo dyes, anthraquinone dyes, pyrazolone dyes, phthalocyanine dyes, xanthracene dyes, indigo dyes, and triphenylmethane dyes. Specific examples of acid dyes include: CI Acid Yellow 17, 23, 42, 44, 79, 142; CI Acid Red 52, 80, 82, 249, 254, 289; CI Acid Blue 9, 45, 249; CI Acid Black 1, 2, 24, 94, etc. Dyes can be used alone or in combination of two or more.

[0191] The lower limit of the pigment content in the ink composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, relative to the total mass of the ink composition. On the other hand, the upper limit of the pigment content in the ink composition is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 6% by mass or less, relative to the total mass of the ink composition. By keeping the pigment content within the above range, the image formed on the recording medium exhibits excellent water resistance, gas resistance, and optical rotation resistance, and the ink also retains its quality well.

[0192] 1.4.2 Resin particles

[0193] The aqueous ink composition included in this embodiment may also contain resin particles. One function of resin particles is to improve the abrasion resistance of images formed by the ink composition adhering to the recording medium. Examples of resin particles include those composed of urethane resins, acrylic resins (including styrene acrylic resins), fluorene resins, polyolefin resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, and ethylene vinyl acetate resins. Uranethane resins, acrylic resins, polyolefin resins, and polyester resins are preferred. These resin particles are mostly used in emulsion form, but can also be supplied in powder form. Furthermore, one type of resin particle may be used alone, or two or more may be used in combination.

[0194] Urea-based resins are a general term for resins containing urethane bonds. Urea-based resins can include polyether-type urethane resins that also contain ether bonds in their main chain, polyester-type urethane resins that also contain ester bonds in their main chain, and polycarbonate-type urethane resins that also contain carbonate bonds in their main chain. In addition, commercially available products can also be used as urethane resins, such as: SUPERFLEX 460, 460s, 840, E-4000 (trade name, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), RESAMIN D-1060, D-2020, D-4080, D-4200, D-6300, D-6455 (trade name, manufactured by Daiichi Seika Kogyo Co., Ltd.), TAKELAC WS-6021, W-512-A-6 (trade name, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), SUNCURE 2710 (trade name, manufactured by LUBRIZOL Co., Ltd.), PERMARIN UA-150 (trade name, manufactured by Sanyo Chemical Co., Ltd.), etc.

[0195] Acrylic resins are a general term for polymers obtained by polymerizing acrylic monomers such as (meth)acrylic acid and (meth)acrylates as at least one component. Examples include resins obtained from acrylic monomers and copolymers of acrylic monomers with other monomers. Examples of acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers, include styrene, for example, as a vinyl monomer.

[0196] Acrylamide, acrylonitrile, etc., can also be used as acrylic monomers. Resin emulsions made from acrylic resins can use commercially available products, such as FK-854 (trade name, manufactured by Chuo Riko Kogyo Co., Ltd.), Mowinyl 952B, 718A (trade name, manufactured by Nippon Synthetic Chemical Co., Ltd.), Nipol LX852, LX874 (trade name, manufactured by Zeon Corporation of Japan).

[0197] It should be noted that, in this specification, acrylic resins can be styrene-acrylic resins as described later. Furthermore, in this specification, the term (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0198] Styrene-acrylic resins are copolymers obtained from styrene monomers and (meth)acrylic monomers, including: styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylate copolymers, styrene-α-methylstyrene-acrylic acid copolymers, styrene-α-methylstyrene-acrylic acid-acrylate copolymers, etc. Styrene-acrylic resins can be commercially available, such as JONCRYL 62J, 7100, 390, 711, 511, 7001, 631, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (trade name, manufactured by BASF), Mowinyl 966A, 975N (trade name, manufactured by Nippon Synthetic Chemicals Co., Ltd.), VINYBLAN 2586 (manufactured by Nissin Chemical Co., Ltd.), etc.

[0199] Polyolefin resins contain olefins such as ethylene, propylene, and butene in their structural backbone, and well-known materials can be appropriately selected. As olefin resins, commercially available products can be used, as well as products such as ARROWBASE CB-1200 and CD-1200 (trade name, manufactured by UNITIKA Co., Ltd.).

[0200] The volume average particle size (D50) 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.

[0201] It should be noted that the volume average particle size (D50) can be measured using a particle size distribution measuring device. Examples of such devices include particle size analyzers based on the dynamic light scattering method (e.g., the "NANOTRAC series" manufactured by MicrotracBEL). The volume average particle size is expressed as the D50 value.

[0202] When the ink composition contains resin particles, the content of resin particles relative to the total mass of the ink composition, in terms of solid content, is 0.1% by mass or more and 20% by mass or less, preferably 0.5% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 5% by mass or less.

[0203] 1.4.3 Wax

[0204] The ink composition of the ink group involved in this embodiment may further include wax. The wax is not particularly limited, and examples include: plant and animal waxes such as carnauba wax, confectionery wax, beeswax, rice wax, and lanolin; mineral waxes such as lignite wax and ceresin wax; paraffin wax, i.e., petroleum-based waxes; synthetic waxes such as carbon wax, Hoechst wax, polyolefin wax, silicone wax, and stearamide; and natural and synthetic wax emulsions or compound waxes such as α-olefin-maleic anhydride copolymers.

[0205] Among these, silicone wax, polyolefin wax, and paraffin wax are preferred, with polyolefin wax being more preferred. Using such waxes tends to improve abrasion resistance.

[0206] As a wax, commercially available products can be used. For example, commercially available polyolefin waxes include: HITEC E-7025P, HITEC E-2213, HITEC E-6500, HITEC E-6314, HITEC E-9460, HITEC E-9015, HITEC E-4A, HITEC E-5403P, HITEC E-8237 (these are trade names, manufactured by Toho Chemical Co., Ltd., polyethylene waxes), and other HITEC series products.

[0207] The wax content relative to the total amount of the ink composition is preferably 0.1% by mass or more and 1.2% by mass or less, more preferably 0.2% by mass or more and 1.0% by mass or less, and even more preferably 0.3% by mass or more and 0.7% by mass or less. By keeping the wax content within the above range, there is a tendency to further improve the abrasion resistance.

[0208] 1.4.4 Other components

[0209] The ink composition included in the ink group according to this embodiment may contain the same components as the first processing liquid, except as described above. That is, the ink composition may contain water, organic solvents, surfactants, amines, and the types and contents of these components may be the same as those in the first processing liquid. It may also further contain urea, sugars, preservatives and fungicides, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, etc., as needed.

[0210] It should be noted that when the ink composition contains organic solvents, the content of organic solvents in the liquid medium component is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass. It should be noted that the liquid medium refers to solvent components such as water and organic solvents.

[0211] The content of organic solvent relative to the total mass of the ink composition is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. The upper limit is preferably 40% by mass or less, more preferably 30% by mass or less, and more preferably 25% by mass or less. Furthermore, the content of organic solvent is also preferably set within the above-mentioned range relative to the total mass of the liquid medium components contained in the ink composition.

[0212] 1.5 White ink composition

[0213] In the ink group involved in this embodiment, the ink composition can be a non-white ink composition, and further includes a white ink composition. Even in such an embodiment, there is a tendency to obtain excellent image quality (ink adhesion and graininess) and abrasion resistance in both low-permeability substrates and non-permeability substrates.

[0214] It should be noted that, in this scheme, the second processing liquid is preferably used together with the white ink composition to record onto the recording medium, which is a non-permeable substrate.

[0215] "White ink composition" is an ink composition containing white pigment.

[0216] "Non-white ink composition" is an ink composition containing non-white pigments. Non-white pigments refer to pigments other than white pigments. Preferred non-white pigments are colored pigments such as cyan, yellow, magenta, and black.

[0217] It should be noted that in this specification, when referred to as white ink composition, white pigment, etc., the phrase "white" does not only refer to pure white, but also includes colors that are colored or achromatic and colors with a glossy finish, as long as they are within the range that can be considered white. Additionally, it includes substances that are called and sold under the names of inks or pigments that can be seen as white.

[0218] To be further quantitatively defined, "white" includes not only records in, for example, CIELAB L * The color is 100, and also includes L. * For those with a score between 60 and 100, a * and b * The colors are ±10 or less. On the other hand, in this specification, when referred to as non-white ink composition, non-white pigment, etc., the phrase "non-white" refers to a color other than "white" as described above.

[0219] 1.5.1 White Pigment

[0220] The white ink composition contains a white pigment. Examples of white pigments include, for example, white metal oxides, barium sulfate, calcium carbonate, and other metal compounds. Examples of metal oxides include titanium dioxide, zinc oxide, silicon dioxide, aluminum oxide, and magnesium oxide. Furthermore, white pigments can use particles with a hollow structure; known substances can be used as hollow-structured particles.

[0221] Typical examples of white pigments include titanium dioxide, such as: TIPAQUE CR-50-2, CR-57, CR-58-2, CR-60-2, CR-60-3, CR-Super-70, CR-90-2, CR-95, CR953, PC-3, PF-690, PF-691, PF-699, PF-711, PF-728, PF-736, PF-737, PF-739, PF-740, PF-742, R-980, UT-771 (all manufactured by Ishihara Sangyo Co., Ltd.), etc.

[0222] In the examples above, titanium dioxide is preferred as a white pigment from the viewpoint of good whiteness and abrasion resistance. A single white pigment can be used, or two or more can be used in combination.

[0223] Preferably, the white pigment can be stably dispersed in the solvent. In the white ink composition, similar to the ink compositions described above, any of the resin-dispersed pigment, dispersant-dispersed pigment, or surface-treated pigment can be used, and can also be used in various mixed forms as needed, preferably containing the resin-dispersed pigment.

[0224] The volume average particle size (D50) of the white pigment is preferably 30.0 nm or more and 600.0 nm or less, more preferably 100.0 nm or more and 500.0 nm or less, and even more preferably 150.0 nm or more and 400.0 nm or less. When the volume average particle size of the white pigment is within the above range, the particles are less prone to sedimentation, resulting in good dispersion stability, and when used in an inkjet recording device, nozzle clogging is less likely to occur. Furthermore, when the volume average particle size of the white pigment is within the above range, the background coverage and visibility of the image are more likely to be improved.

[0225] The content (solid content) of white pigment in the white ink composition is preferably 0.5% by mass or more and 20.0% by mass or less relative to the total mass of the white ink composition, more preferably 1.0% by mass or more and 20.0% by mass or less, and even more preferably 3.0% by mass or more and 15.0% by mass or less. If the content is within the above range, there is a tendency to obtain an image with sufficient visibility.

[0226] 1.5.2 Chelating agents

[0227] The white ink composition may also contain chelating agents. Specific chelating agents are not particularly limited, but examples include: compounds of ethylenediaminetetraacetic acid (EDTA), N-(2-hydroxyethyl)ethylenediaminetriacetic acid, ethylenediaminesuccinic acid, iminodisulfosuccinic acid, dicarboxymethylglutamic acid, bis(2-aminoethyl)ethylene glycoltetraacetic acid, bis(2-aminophenyl)ethylene glycoltetraacetic acid, bis(2-hydroxyethyl)glycine, 1,2-diaminocyclohexanetetraacetic acid, diethylenetriaminepentaacetic acid, iminodiacetic acid, N-(2-hydroxyethyl)iminodiacetic acid, hypozinotriacetic acid, hypozinotrimethylphosphate, triethylenetetraaminehexaacetic acid, and tetra(2-pyridylmethyl)ethylenediamine.

[0228] The content of the chelating agent in the white ink composition is preferably 0.001% by mass or more and 0.100% by mass or less relative to the total mass of the white ink composition, more preferably 0.003% by mass or more and 0.050% by mass or less, and even more preferably 0.005% by mass or more and 0.030% by mass or less.

[0229] 1.5.3 Other Components

[0230] In the white ink composition, the components other than those described above can be the same as those in the aforementioned ink composition. That is, the white ink composition may contain water, organic solvents, surfactants, resin particles, waxes, and amines, and the types and amounts of these components can be the same as those in the aforementioned ink composition. It may also further contain urea, sugars, preservatives and fungicides, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, etc., as needed.

[0231] It should be noted that the content of resin particles in the white ink composition, relative to the total mass of the white ink composition and in terms of solid content, is preferably 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 20% by mass or less, and even more preferably 3% by mass or more and 10% by mass or less. If the content of resin particles is within this range, there is a tendency to form a white image with sufficient abrasion resistance.

[0232] It should be noted that the wax content in the white ink composition, relative to the total mass of the white ink composition and calculated as solid content, is preferably 0.1% by mass or more and 1.2% by mass or less, more preferably 0.2% by mass or more and 1.0% by mass or less, and even more preferably 0.3% by mass or more and 0.7% by mass or less. By keeping the wax content within the above range, there is a tendency to further improve the abrasion resistance.

[0233] 1.6 Transparent ink composition

[0234] The ink group involved in this embodiment includes a transparent ink composition containing resin, which is an ink other than the aforementioned ink composition and white ink composition.

[0235] It should be noted that, in this case, the first processing liquid can be used together with the transparent ink composition to record on a recording medium that is a low-permeability substrate. Alternatively, the second processing liquid can be used together with the transparent ink composition to record on a recording medium that is a non-permeable substrate.

[0236] It should be noted that the "transparent ink composition" is not an ink used for coloring recording media, but rather an ink used for other purposes. These other purposes include, but are not limited to, improving the abrasion resistance of recorded materials, adjusting the gloss of recording media, and enhancing the adhesion and color development of colored inks. Furthermore, the transparent ink composition is not a processing liquid and does not contain a coagulant.

[0237] It should be noted that the transparent ink composition may also not contain the above-mentioned pigments. The content of pigments in the transparent ink composition is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less. The lower limit of the content can also be 0% by mass.

[0238] 1.6.1 Resin

[0239] The transparent ink composition contains a resin. As the resin, a substance formed by dispersing or dissolving a polymer component in a solvent in the form of an emulsion can be used. Preferably, a substance formed by dispersing or dissolving a polymer component in the form of an emulsion is used; particularly preferred are substances formed by dispersing a polymer component (resin particles). The resin particles can be the same as those in the ink composition described above.

[0240] The content of resin particles in the transparent ink composition, relative to the total mass of the transparent ink composition and in terms of solid content, is preferably 1% by mass or more and 40% by mass or less, more preferably 3% by mass or more and 30% by mass or less, even more preferably 5% by mass or more and 20% by mass or less, and particularly preferably 7% by mass or more and 15% by mass or less. By keeping the content of resin particles within the above range, there is a tendency to further improve the abrasion resistance.

[0241] 1.6.2 Other components

[0242] In the transparent ink composition, the components other than those described above can be the same as those in the aforementioned ink composition. That is, the transparent ink composition may contain water, organic solvents, surfactants, waxes, and amines, and the types and amounts of these components can be the same as those in the aforementioned ink composition. It may also further contain urea, sugars, preservatives and fungicides, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, etc., as needed.

[0243] It should be noted that the wax content in the transparent ink composition, relative to the total mass of the transparent ink composition and calculated as solid content, is preferably 0.3% by mass or more and 3.5% by mass or less, more preferably 0.5% by mass or more and 3.0% by mass or less, and even more preferably 1.0% by mass or more and 2.5% by mass or less. By keeping the wax content within the above range, there is a tendency to further improve the abrasion resistance.

[0244] 2. Recording device

[0245] An embodiment of the present invention relates to a recording apparatus that records to a recording medium. The recording apparatus includes the aforementioned ink group and performs: a first recording using the aforementioned ink composition and the aforementioned first processing liquid to record a recording medium that is a low-permeability substrate, and a second recording using the aforementioned ink composition and the aforementioned second processing liquid to record a recording medium that is a non-permeable substrate.

[0246] According to the recording apparatus of this embodiment, it is able to include the aforementioned ink group and select the appropriate processing liquid for recording based on the recording medium. Therefore, excellent image quality (ink adhesion and graininess) and abrasion resistance can be obtained in recordings on both low-permeability and non-permeability substrates.

[0247] The recording medium used in the recording apparatus according to this embodiment, which is a low-permeability substrate and a non-permeability substrate, can have the same configuration as the aforementioned medium.

[0248] It should be noted that in the examples described below, a method is used in which the ink composition and processing liquid of the ink group are ejected from the nozzle of the inkjet head and adhered to the recording medium. However, the method of liquid adhesion is not limited to inkjet printing and can also be spraying, etc.

[0249] Figure 2 This is a schematic cross-sectional view illustrating the recording apparatus according to this embodiment. According to this inkjet recording apparatus 1, it can include the aforementioned ink group and perform the aforementioned first recording and second recording.

[0250] Figure 3 It is shown Figure 2 A perspective view of an example of the configuration of the carriage periphery of an inkjet recording device 1. Figure 2 , 3 As shown, the inkjet recording device 1 includes: an inkjet head 2, an IR heater 3, a pressure plate heater 4, a heating type heater 5, a cooling fan 6, a preheater 7, an air exchange fan 8, a carriage 9, a pressure plate 11, a carriage moving mechanism 13, a transport unit 14, and a control unit CONT. The inkjet recording device 1... Figure 3 The control unit CONT shown controls the overall operation of the inkjet recording device 1.

[0251] The inkjet head 2 is configured to eject an ink composition and processing liquid from its nozzles to adhere to the recording medium M. It should be noted that, hereinafter, when simply referred to as "composition," it refers to at least one of the aforementioned first processing liquid, second processing liquid, ink composition, and other optional compositions.

[0252] exist Figure 3 In this example, inkjet head 2 is a serial inkjet head that scans the recording medium M more than once along the main scanning direction to allow the processing liquid and ink composition to adhere to the recording medium M. Inkjet head 2 is mounted on... Figure 3 The carriage 9 is shown. The inkjet head 2 scans the recording medium M at least once along the main scanning direction by means of a carriage moving mechanism 13 that moves the carriage 9 along the width direction of the recording medium M. The width direction of the medium is the main scanning direction of the inkjet head 2. The scanning along the main scanning direction is also called the main scan.

[0253] Furthermore, here, the main scanning direction is the direction in which the carriage 9, which carries the inkjet head 2, moves. Figure 2 In this context, the main scanning direction intersects the secondary scanning direction, which is the transport direction of the recording medium M, as indicated by arrow SS.Figure 3 In this diagram, the width direction of the recording medium M, i.e., the direction shown by S1-S2, is the main scanning direction MS, and the direction shown by T1→T2 is the sub-scanning direction SS. It should be noted that in one scan, scanning is performed along the main scanning direction, i.e., either arrow S1 or arrow S2. Next, the main scan of the inkjet head 2 and the sub-scanning, which transports the recording medium M, are performed at least once, thereby recording the recording medium M. That is, the process of attaching the processing liquid to the recording medium (processing liquid attachment process) and the process of attaching the ink composition to the recording medium (ink attachment process) are performed by at least one main scan in which the inkjet head 2 moves along the main scanning direction, and at least one sub-scanning in which the recording medium M moves in a sub-scanning direction intersecting the main scanning direction.

[0254] The ink cartridge 12, which supplies processing fluid and ink composition to the inkjet head 2, comprises multiple independent ink cartridges. The ink cartridge 12 is detachably mounted on the carriage 9 on which the inkjet head 2 is mounted. Each of the multiple ink cartridges is filled with a different type of processing fluid, ink composition, and optionally other compositions, and each composition is supplied from the ink cartridge 12 to each nozzle. It should be noted that although an example of the ink cartridge 12 being mounted on the carriage 9 is shown, it is not a limitation; the ink cartridge 12 may also be located in a location other than the carriage 9, and supplied to each nozzle via a supply pipe not shown in the figure.

[0255] The recording apparatus according to this embodiment selects the type of processing liquid used for recording based on the type of recording medium being recorded. That is, when recording on a recording medium that is a low-permeability substrate, a first processing liquid filled in the ink cartridge 12 is selected for first recording. Conversely, when recording on a recording medium that is a non-permeable substrate, a second processing liquid filled in the ink cartridge 12 is selected for second recording.

[0256] The recording apparatus of this embodiment can adhere a processing liquid to the recording medium via inkjet printing in both the first and second recordings. In the first recording, the processing liquid is ejected according to a first droplet mass and adhered to the recording medium. In the second recording, the processing liquid is ejected according to a second droplet mass smaller than the first droplet mass and adhered to the recording medium. In this approach, superior image quality and abrasion resistance are tended to be obtained in recordings on both low-permeability and non-permeability substrates.

[0257] It should be noted that "droplet mass" refers to the mass of each droplet ejected from the nozzle of inkjet head 2.

[0258] The mass of the first droplet is preferably 8 ng or less, more preferably 7 ng or less, even more preferably 6 ng or less, and particularly preferably 5 ng or less. The lower limit of the mass of the first droplet is preferably more than 3 ng, more preferably more than 4 ng.

[0259] The mass of the second droplet is preferably 6 ng or less, more preferably 5 ng or less, even more preferably 4 ng or less, and particularly preferably 3 ng or less. The lower limit of the mass of the second droplet is preferably more than 1 ng, more preferably more than 2 ng.

[0260] The mass of the second droplet is preferably 0.5 ng or less than that of the first droplet, more preferably 1.0 ng or more, even more preferably 1.5 ng or more, and even more preferably 2.0 ng or more. Preferably, it is 10 ng or less, and more preferably 5 ng or less.

[0261] It should be noted that when the white ink composition is applied to the recording medium by inkjet printing, the droplet mass of the white ink composition is preferably 16 ng or less, more preferably 14 ng or less, even more preferably 12 ng or less, and particularly preferably 10 ng or less. The lower limit is preferably more than 6 ng, and more preferably more than 8 ng.

[0262] Furthermore, when the transparent ink composition is applied to the recording medium by inkjet printing, the droplet mass of the transparent ink composition is preferably 8 ng or less, more preferably 7 ng or less, even more preferably 6 ng or less, and particularly preferably 5 ng or less. The lower limit is preferably more than 3 ng, more preferably more than 4 ng.

[0263] When the composition is ejected through the inkjet head 2, existing known methods can be used. Here, a method of ejecting droplets by vibration of a piezoelectric element is used, that is, an ejection method that forms ink droplets by mechanical deformation of an electrostrictive element.

[0264] The inkjet recording apparatus 1 may include a heating mechanism for a primary drying process, i.e., drying the recording medium M while the composition is ejected from the inkjet head 2 and adheres to it. The heating mechanism can be conductive, blower-type, or emission-type. A conductive heating mechanism conducts heat from a component in contact with the recording medium to the recording medium. Examples include a pressure plate heater 4. A blower-type heating mechanism delivers ambient or warm air to the recording medium M to dry the composition. Examples include an exhaust fan 8. An emission-type heating mechanism emits heat-generating rays into the recording medium M to heat it. Examples include an IR heater 3. These heating mechanisms can be used individually or in combination.

[0265] For example, the inkjet recording apparatus 1 may include an IR heater 3 and a platen heater 4 as heating mechanisms. When drying the recording medium M in a single drying process, the IR heater 3, the platen heater 4, the ventilation fan 8, etc., can be used.

[0266] It should be noted that if an IR heater 3 is used, the recording medium M can be heated by infrared radiation from the inkjet head 2 side in an emission manner. Therefore, the inkjet head 2 can also be heated simultaneously, but compared to cases where the recording medium M is heated from the reverse side, such as by a pressure plate heater 4, the temperature can be increased regardless of the thickness of the recording medium M. Furthermore, various fans (such as the ventilation fan 8 shown in the figure) can be provided to blow warm air or air at the same temperature as the environment onto the recording medium M to dry the composition on the recording medium M.

[0267] The platen heater 4 heats the recording medium M across the platen 11 at a position opposite the inkjet head 2, enabling the composition ejected through the inkjet head 2 to dry rapidly from the moment it adheres to the recording medium M. The platen heater 4 can be positioned downstream or upstream of the inkjet head 2 in the transport direction of the recording medium M. Insufficient heating of the inkjet head 2 by the platen heater 4 may suppress the drying of the liquid within the nozzle, reducing clogging, etc. The platen heater 4 can heat the recording medium M through conduction. The platen heater 4 is used as needed in the recording method. When using the platen heater 4, the surface temperature of the recording medium M is controlled to be below 45.0°C, preferably below 40.0°C. It should be noted that in a line-type inkjet recording apparatus, the platen heater 4 corresponds to the lower heater. If a primary drying step using a heating mechanism is not performed, the heating mechanism may not be required; in the recording apparatus according to this embodiment, it is preferable not to have a heating mechanism.

[0268] It should be noted that, in the ink adhesion process, the upper limit of the surface temperature of the recording medium M is preferably 45.0°C or less, more preferably 40.0°C or less, even more preferably 38.0°C or less, and particularly preferably 35.0°C or less. Furthermore, the lower limit of the surface temperature of the recording medium M is preferably 25.0°C or more, more preferably 28.0°C or more, even more preferably 30.0°C or more, and particularly more preferably 32.0°C or more.

[0269] In the recording method described later, after the ink adhesion step, a post-heating step can be included to heat the recording medium M, thereby drying and fixing the composition. This post-heating is also referred to as secondary heating.

[0270] The heating heater 5 used in the post-heating process is a heater used to dry and cure the composition attached to the recording medium M, i.e., for secondary heating or secondary drying. The heating heater 5 can be used in the post-heating process. By heating the recording medium M after image recording with the heating heater 5, moisture and other substances contained in the composition evaporate and disperse more quickly. When the composition contains resin, an ink film is formed by the resin. In this way, the film of the composition is firmly fixed or adhered to the recording medium M, exhibiting excellent film-forming properties, and enabling the acquisition of excellent high-quality images in a short time.

[0271] The upper limit of the surface temperature of the recording medium M brought about by the heating heater 5 is preferably 120.0°C or less, more preferably 100.0°C or less, even more preferably 90.0°C or less, and even more preferably 80.0°C or less. Furthermore, the lower limit of the surface temperature of the recording medium M is preferably 60.0°C or more, more preferably 70.0°C or more. By maintaining the temperature within this range, high-quality images can be obtained in a short time. It should be noted that in a line-type inkjet recording device, the heating heater 5 corresponds to the rear heater and is composed of a carbon heater or the like.

[0272] The inkjet recording device 1 may have a cooling fan 6. By cooling the composition on the recording medium M with the cooling fan 6 after the composition attached to the recording medium M is dried, a coating film with good adhesion can be formed on the recording medium M.

[0273] Additionally, the inkjet recording apparatus 1 may also include a preheater 7 for preheating the recording medium M before attaching the composition to it. It should be noted that in a line-type inkjet recording apparatus, the preheater 7 may also be provided as a heating mechanism.

[0274] Below the carriage 9 are a pressure plate 11 that supports the recording medium M, a carriage moving mechanism 13 that moves the carriage 9 relative to the recording medium M, and a conveying unit 14 that serves as a roller for conveying the recording medium M along the sub-scanning direction. The operation of the carriage moving mechanism 13 and the conveying unit 14 is controlled by the control unit CONT.

[0275] Figure 4 This is a functional block diagram of the inkjet recording device 1. The control unit CONT is a control unit for controlling the inkjet recording device 1. The interface unit 101 (I / F) is used for sending and receiving data between the computer 130 (COMP) and the inkjet recording device 1. The CPU 102 is a processing unit for controlling the overall operation of the inkjet recording device 1. The memory 103 (MEM) is used to store the program and operating area of ​​the CPU 102. The CPU 102 controls each unit through the unit control circuit 104 (UCTRL). It should be noted that the detector group 121 (DS) detects the condition inside the inkjet recording device 1, and the control unit CONT controls each unit based on the detection results.

[0276] The transport unit 111 (CONVU) controls the sub-scanning (transport) of the inkjet recording, specifically controlling the transport direction, transport distance, and transport speed of the recording medium M. Specifically, the transport direction, transport distance, and transport speed of the recording medium M are controlled by controlling the rotation direction, rotation amount, and rotation speed of the motor-driven transport roller.

[0277] The carriage unit 112 (CARU) controls the main scan (track) of inkjet recording; specifically, it causes the inkjet head 2 to reciprocate along the main scan direction. The carriage unit 112 includes a carriage 9 that carries the inkjet head 2 and a carriage moving mechanism 13 for reciprocating the carriage 9.

[0278] The head unit 113 (HU) controls the amount of composition ejected from the nozzles of the inkjet head 2. For example, when the nozzles of the inkjet head 2 are driven by piezoelectric elements, it controls the operation of the piezoelectric elements on each nozzle. The head unit 113 controls the timing of the attachment of each composition, the dot size of the composition, etc. In addition, the amount of composition attached per scan is controlled by the combination of the control of the carriage unit 112 and the head unit 113.

[0279] When the first processing liquid is selected as the processing liquid for recording, the printhead unit 113 can be controlled to eject the first processing liquid instead of the second processing liquid from the nozzle of the printhead 2. This allows for first recording. Conversely, when the second processing liquid is selected as the processing liquid for recording, the printhead unit 113 can be controlled to eject the second processing liquid instead of the first processing liquid from the nozzle of the printhead 2. This allows for second recording.

[0280] The drying unit 114(DU) controls the temperature of various heaters, including the IR heater 3, preheater 7, pressure plate heater 4, and heating heater 5.

[0281] The detector assembly 121 (DS) monitors the conditions within the inkjet recording apparatus 1. For example, it detects whether the recording medium M is either a low-permeability substrate or a non-permeability substrate. If a low-permeability substrate is detected as the type of recording medium M, the control unit CONT control head unit 113 does not eject the second processing liquid from the nozzle of the inkjet head 2, but ejects the first processing liquid instead. If a non-permeability substrate is detected as the type of recording medium M, the control unit CONT control head unit 113 causes it to not eject the first processing liquid from the nozzle of the inkjet head 2, but ejects the second processing liquid instead.

[0282] The inkjet recording apparatus 1 described above alternately performs the actions of moving the carriage 9 carrying the inkjet head 2 along the main scanning direction and the transport action (sub-scanning). During each pass, the control unit CONT controls the carriage unit 112 to move the inkjet head 2 along the main scanning direction, while the control head unit 113 ejects droplets of the composition from the predetermined nozzle orifice of the inkjet head 2, causing the droplets to adhere to the recording medium M. Furthermore, the control unit CONT controls the transport unit 111 to transport the recording medium M along the transport direction at a predetermined feed rate during the transport action.

[0283] In the inkjet recording apparatus 1, a recording area with multiple droplets attached is gradually conveyed by repeatedly performing main scans (tracks) and sub-scans (transport actions). Next, the droplets attached to the recording medium M are dried by the post-heater 5, thus completing the image. The completed recording is then wound into a roller shape by a winding mechanism or transported by a flat-head mechanism.

[0284] The above describes a serial recording apparatus equipped with a serial inkjet head and used for a serial recording method. On the other hand, the inkjet head 2 can also be a line-type head. A line-type recording apparatus inkjet head refers to a head with nozzles arranged along a length exceeding the recording width of the recording medium M, which applies an ink composition to the recording medium M in one pass. Furthermore, the inkjet head 2 can also be a laterally type head. A laterally type head refers to a head (carriage) equipped with a mechanism for moving along the X and Y directions (main scanning direction and sub-scanning direction) as described in Japanese Patent Application Publication No. 2002-225255.

[0285] The recording device involved in this embodiment can be a recording device of any recording mode, such as serial mode, row mode, or landscape mode.

[0286] 3. Recording Method

[0287] An embodiment of the present invention relates to a recording method for recording to a recording medium using the above-described ink composition, comprising the following steps: selecting a recording liquid from the above-described first processing liquid and the above-described second processing liquid; attaching the selected processing liquid to the recording medium; and attaching the above-described ink composition to the recording medium. The recording method is any one of the following: a first recording in which the selected processing liquid is the above-described first processing liquid and the recording medium is a low-permeability substrate; or a second recording in which the selected processing liquid is the above-described second processing liquid and the recording medium is a non-permeable substrate.

[0288] According to the recording method described in this embodiment, the above-mentioned ink group can be used to select the appropriate processing liquid for recording based on the recording medium. Therefore, excellent image quality (ink adhesion and graininess) and abrasion resistance can be obtained in recordings on both low-permeability and non-permeability substrates.

[0289] The recording medium, which is a low-permeability substrate and a non-permeability substrate, used for recording by the recording method described in this embodiment can have the same configuration as described above.

[0290] 3.1 Selecting the process

[0291] The recording method according to this embodiment includes the step of selecting a processing liquid for recording from the first processing liquid and the second processing liquid (selection step) described above.

[0292] In the selection process, when a first processing liquid is selected as the recording liquid, first recording can be performed on a recording medium that is a low-permeability substrate. On the other hand, when a second processing liquid is selected as the recording liquid, second recording can be performed on a recording medium that is a non-permeable substrate. In this way, in the recording method according to this embodiment, the processing liquid used can be selected for recording according to the recording medium. Therefore, excellent image quality (ink adhesion and graininess) and abrasion resistance can be obtained in both low-permeability and non-permeable substrates.

[0293] Examples of selection methods include: a method where the user inputs the selection from the input section of the recording device; a method where the selection is made using the processing fluid filled in the recording device; and a method where the recording device automatically selects based on recording conditions such as the type of recording medium.

[0294] 3.2 Processing liquid adhesion procedure

[0295] The recording method according to this embodiment includes a step of attaching a selected processing liquid to a recording medium (processing liquid attachment step). That is, if a first processing liquid is selected in the aforementioned selection step, the first processing liquid is attached to the recording medium in the processing liquid attachment step. On the other hand, if a second processing liquid is selected in the aforementioned selection step, the second processing liquid is attached to the recording medium in the processing liquid attachment step.

[0296] It should be noted that the method of applying the processing liquid to the recording medium is not particularly limited, and can be performed by, for example, coating with a brush, coating with a roller, spraying, coating with a bar coater, or inkjet printing. Among these, the processing liquid is preferably applied to the recording medium by inkjet printing. Therefore, in recordings on both low-permeability and non-permeability substrates, there is a tendency to obtain superior image quality and abrasion resistance.

[0297] The preferred treatment fluid adhesion amount (treatment fluid adhesion amount A) is 2.0 mg / inch per unit area of ​​the recording area of ​​the recording medium. 2 The following is more preferably 1.5 mg / inch 2 The following is a further preferred concentration: 1.2 mg / inch 2 The following applies. The lower limit of the adhesion amount is not particularly limited, but is preferably 0.3 mg / inch. 2 More preferably 0.5 mg / inch 2 That's all. Furthermore, a concentration exceeding 0.6 mg / inch is preferred. 2 More preferably, exceeding 0.8 mg / inch 2Further optimization of doses exceeding 1.0 mg / inch 2 If the amount of the treatment liquid adhering is within the above range, then in both low-permeability and non-permeability substrates, there is a tendency to obtain better image quality and abrasion resistance.

[0298] Furthermore, the amount of processing liquid adhering is preferably two or more depending on the amount of ink composition described later. This allows for more appropriate control of the reaction between the ink and the processing liquid, thus resulting in superior image quality and abrasion resistance in recordings on both low-permeability and non-permeability substrates.

[0299] When the amount of ink composition adhered in the ink adhesion process described later is set as ink adhesion amount A, it is preferable to perform the treatment liquid adhesion process with the amount of treatment liquid adhered to the recording area being treatment liquid adhesion amount A. On the other hand, when the amount of ink composition adhered in the ink adhesion process described later is set as ink adhesion amount B, it is preferable to perform the treatment liquid adhesion process with the amount of treatment liquid adhered to the recording area being the treatment liquid adhesion amount B described below. Treatment liquid adhesion amount A corresponds to the amount of treatment liquid adhered to the recording area where the ink adhesion amount is the maximum ink adhesion amount recorded.

[0300] The amount of treatment fluid adhering to B is equivalent to the amount of treatment fluid adhering to the recorded area, which is a specified amount of ink adhering to the area that is less than the maximum amount of ink adhering to the record.

[0301] The preferred treatment fluid adhesion amount B is 1.0 mg / inch per unit area of ​​the recording area of ​​the recording medium. 2 The following is more preferably 0.8 mg / inch. 2 The following is a further preferred dosage: 0.6 mg / inch 2 The following applies. The lower limit of the adhesion amount is not particularly limited, but is preferably 0.05 mg / inch. 2 More preferably 0.1 mg / inch 2 That's all. Furthermore, a concentration exceeding 0.3 mg / inch is preferred. 2 More preferably, exceeding 0.4 mg / inch 2 Further optimization is needed for doses exceeding 0.5 mg / inch. 2 .

[0302] It should be noted that the preferred treatment fluid adhesion amount A is 0.2 mg / inch higher than the treatment fluid adhesion amount B. 2 The above, preferably 0.4 mg / inch more. 2 The above further optimizes the dosage to 0.6 mg / inch. 2 The above. Further preferred dosage is 0.6–1.0 mg / inch. 2 .

[0303] The amount of treatment fluid adhering to B is preferably 40-60% by mass of the amount of treatment fluid adhering to A, more preferably 45-55%.

[0304] In the processing liquid adhesion process, it is preferable to adhere the processing liquid droplets in a regular pattern. As a result, the processing liquid adheres evenly to the recording medium, and the ink droplets and processing liquid droplets can easily come into contact. This tends to result in superior image quality and abrasion resistance in recordings on both low-permeability and non-permeability substrates.

[0305] Here, "regular pattern" refers to a pattern formed by regularly arranging droplets attached to a point represented by printing resolution [dpi].

[0306] Figure 5 It is a diagram that schematically illustrates a regular pattern. Figure 5 One grid shown corresponds to one dot in terms of printing resolution [dpi], and the black circle represents an attached droplet. For example, in Figure 5 The image shows a regular pattern formed by attaching droplets at half the size of a single point at a printing resolution [dpi] (one droplet for every two points). Similarly, regular patterns are also formed by attaching droplets at one-third, one-quarter, one-fifth, and one-sixth of the size of a single point at a printing resolution [dpi].

[0307] It should be noted that if the arrangement of droplets on one grid extending along the main scanning direction is regular, and the arrangement of droplets on one grid extending along the sub-scanning direction is also regular, then the pattern is a regular pattern. For example, a regular pattern is one in which droplets on one grid extending along the main scanning direction are arranged such that droplets are attached at half the distance from one point of the printing resolution [dpi], and droplets on one grid extending along the sub-scanning direction are attached such that droplets are attached at one-fifth the distance from one point of the printing resolution [dpi].

[0308] On the other hand, "irregular pattern" refers to a pattern that does not belong to the aforementioned regular patterns. For example, regarding the arrangement of droplets on one grid extending along the main scanning direction, if an arrangement of about 10 droplets is confirmed and this arrangement is irregular, it can be considered an irregular pattern.

[0309] In the recording method described in this embodiment, the recording resolution of the processing liquid is preferably 1200×1200 dpi or higher, and more preferably 1200×1200 dpi or higher in a single main scan. With such a recording resolution, there is a tendency to obtain superior image quality and abrasion resistance in both low-permeability and non-permeability substrates.

[0310] 3.3 Ink Adhesion Process

[0311] The recording method according to this embodiment includes a step of adhering an ink composition to a recording medium (ink adsorption step).

[0312] It should be noted that the method of adhering the ink composition to the recording medium is not particularly limited, and can be performed by means such as spraying or inkjet printing. Among these methods, inkjet printing is preferred for adhering the ink composition to the recording medium. This results in superior image quality and abrasion resistance in recordings on both low-permeability and non-permeability substrates. The following transparent ink adhering process and white ink adhering process are also the same.

[0313] The ink composition can have two or more adhesion amounts as needed. For example, ink adhesion amount A is preferably 20.0 mg / inch per unit area of ​​the recording area of ​​the recording medium. 2 Below, 15.0 mg / inch is preferred. 2 Hereinafter, 10.0 mg / inch is further preferred. 2 The following is preferred. Furthermore, 8.0 mg / inch is preferred. 2 The following is not specifically limited; however, it is preferred to exceed 0.6 mg / inch. 2 More preferably, exceeding 0.8 mg / inch 2 Further optimization of doses exceeding 1.0 mg / inch 2 Furthermore, 4.0 mg / inch is preferred. 2 Above, preferably 5.0 mg / inch 2 That's all. Ink adhesion amount A corresponds to the maximum ink adhesion amount recorded.

[0314] Ink adhesion amount B is equivalent to a specified ink adhesion amount that is less than the maximum ink adhesion amount recorded.

[0315] For example, the ink adhesion amount B is preferably 10.0 mg / inch per unit area of ​​the recording area of ​​the recording medium. 2 The following is more preferably 8.0 mg / inch. 2 The following is a further preferred dosage: 6.0 mg / inch 2 The following applies. The lower limit of the adhesion amount is not particularly limited, but is preferably greater than 0.3 mg / inch. 2 More preferably, exceeding 0.4 mg / inch 2 Further optimization is needed for doses exceeding 0.5 mg / inch. 2 Furthermore, 1.0 mg / inch is preferred. 2 More preferably 2.0 mg / inch 2 above.

[0316] The ink adhesion amount B is preferably 60-80% by mass of the ink adhesion amount A, and more preferably 65-75% by mass.

[0317] It should be noted that the preferred ink adhesion amount A is 0.2 mg / inch higher than the ink adhesion amount B. 2 The above, preferably 0.4 mg / inch more. 2 The above further optimizes the dosage to 0.6 mg / inch. 2 The above. A preferred dosage is 1.0–3.0 mg / inch. 2 .

[0318] In the recording method described in this embodiment, it is preferable to spray the processing liquid and ink composition in the same scan and then overlap them on the recording medium, with the maximum time difference between the adhesion of the processing liquid and the adhesion of the ink composition being less than 1 second. Under such circumstances, there is a tendency to obtain superior image quality and abrasion resistance in recordings on both low-permeability and non-permeability substrates.

[0319] It should be noted that "spraying the processing liquid and ink composition in the same scan and allowing them to overlap and adhere to the recording medium" can refer to attaching the processing liquid and ink composition to the same scan area of ​​the recording medium through the same master scan. This is called simultaneous ink dripping.

[0320] It should be noted that "the maximum time difference between the adhesion of the processing liquid and the adhesion of the ink composition" refers to the time difference between the adhesion of the processing liquid to the recording medium and the adhesion of the ink composition to the recording medium. This is the maximum time difference when using multiple ink compositions.

[0321] The maximum time is preferably within 0.8 seconds, and even more preferably within 0.6 seconds. In addition, the lower limit is not particularly limited, but is preferably 0.1 seconds or more, more preferably 0.3 seconds or more, and even more preferably 0.5 seconds or more.

[0322] 3.4 Transparent Ink Adhesion Process

[0323] The recording method according to this embodiment can include the above-described step of further adhering the resin-containing transparent ink composition to the recording medium (transparent ink adhering step). Therefore, it tends to further improve abrasion resistance.

[0324] The preferred adhesion amount of the transparent ink composition is 5 mg / inch per unit area of ​​the recording area of ​​the recording medium. 2 The following is preferred: 3 mg / inch 2 The following is further preferred: 2 mg / inch 2 The following applies. The lower limit of the adhesion amount is not particularly limited, but is preferably greater than 0.1 mg / inch. 2More preferably, more than 0.3 mg / inch 2 Further optimization is needed for doses exceeding 0.5 mg / inch. 2 .

[0325] 3.5 White ink adhesion process

[0326] The recording method described in this embodiment can include a step of adhering the above-mentioned white ink composition to the recording medium (white ink adhering step). Even in this case, there is a tendency to obtain superior image quality and abrasion resistance in both low-permeability substrates and non-permeability substrates.

[0327] The preferred adhesion amount of the white ink composition is 20 mg / inch per unit area of ​​the recording area of ​​the recording medium. 2 The following is more preferably 17 mg / inch. 2 The following is a further preferred value: 15 mg / inch 2 The following applies. The lower limit of the adhesion amount is not particularly limited, but is preferably greater than 5 mg / inch. 2 More preferably, exceeding 7 mg / inch 2 Further optimization of more than 9mg / inch 2 .

[0328] It should be noted that the order of the treatment liquid application process, the ink application process, the transparent ink application process, and the white ink application process is not particularly limited. For example, the ink application process can be performed after or simultaneously with the treatment liquid application process, or it can be performed after the ink application process.

[0329] 3.6 Single Drying Process

[0330] The recording method according to this embodiment may further include a primary drying step to dry droplets adhering to the recording medium. By including this step, the drying properties of the ink can be improved in the early stages after the ink composition or the like has adhered to the recording medium, resulting in better abrasion resistance. It should be noted that the recording method according to this embodiment preferably does not include a primary drying step accompanied by heating.

[0331] A primary drying process is a process of drying ink in the early stages after the ink composition has adhered isotropically to the recording medium. A primary drying process is used to dry and remove at least a portion of the solvent components of the ink adhered to the recording medium to a degree that at least reduces the flow of the ink. Ink droplets falling onto the recording medium are preferably dried by the primary drying process within 0.5 seconds of the droplet falling.

[0332] As a drying process, examples include: blower-type, emission-type, heat transfer-type, and combinations thereof. Among them, blower-type refers to the method of drying by using a fan or similar device to blow room temperature air (room temperature air) or by blowing air while heating (warm air) onto the recording medium; emission-type refers to the emission of IR heaters or microwaves; heat transfer-type is based on heating the recording medium by a pressure plate heater or similar device.

[0333] In a single drying process, when drying is carried out by blowing air, the air velocity is preferably 0.5 to 15 m / s, more preferably 0.5 to 10 m / s, even more preferably 1 to 5 m / s, and particularly preferably 2 to 3 m / s. This air velocity is the air velocity near the surface of the recording medium.

[0334] The blower air temperature is preferably below 50°C, more preferably above 10°C. Furthermore, it is preferably 15–45°C, more preferably 20–49°C. More preferably 23–40°C, more preferably 25–35°C, and even more preferably 25–28°C. The blower air temperature can also be room temperature.

[0335] With or without a primary drying step, the surface temperature of the recording medium in the ink adhesion step is preferably 45.0°C or lower, more preferably 40.0°C or lower, even more preferably 38.0°C or lower, and particularly preferably 35.0°C or lower. Furthermore, the lower limit of the surface temperature of the recording medium M is preferably 25.0°C or higher, more preferably 28.0°C or higher, even more preferably 30.0°C or higher, and particularly more preferably 32.0°C or higher.

[0336] It should be noted that when heating is involved in a single drying process, the single drying process can allow the ink to adhere to the heated recording medium, or heating can be performed early after adhesion. Preferably, the single drying process allows the ink droplet falling onto the recording medium to begin heating within 0.5 seconds of its droplet falling.

[0337] When heating is involved in a single drying process, heating can be performed at least at any time before, during, or early after the ink adhesion process, preferably simultaneously. This heating sequence allows for the ink adhesion process to be performed.

[0338] It should be noted that the surface temperature of the recording medium in a single drying process has several meanings. First, when ink is applied to the recording medium after the single drying process, it is the surface temperature of the recording medium at the time of ink application. Second, when the single drying process is performed early after ink application, it is the surface temperature of the recording medium during the single drying process. Furthermore, it is also the maximum temperature generated by the single drying process during the entire drying process. In these cases, the surface temperature of the recording medium in the single drying process preferably falls within the aforementioned range.

[0339] In addition, the surface temperature of the recording medium when there is no heating during a single drying process refers to the surface temperature of the recording medium when the ink is applied.

[0340] 3.7 Post-heating process

[0341] The recording method described in this embodiment may also include a post-heating step, that is, for the recording medium after the adsorption of the treatment liquid and ink composition, the surface of the recording medium is heated at a temperature preferably 60–120°C, more preferably 70–110°C, and even more preferably 80–100°C after the pressure plate passes through. This results in improved drying properties and a tendency to obtain recordings with superior abrasion resistance, which is therefore preferred.

[0342] The post-heating process is the process of completing the recording and ensuring the recorded material is sufficiently dry to a usable state. The post-heating process is used to thoroughly dry solvent components such as ink and to heat resin particles that may be contained in the ink to form a flat film.

[0343] It should be noted that heating of the recording medium in the post-heating process can be performed using a suitable heating device, for example, when using an inkjet recording device. Furthermore, it is not limited to the heating device found in inkjet recording devices; any suitable heating device can be used.

[0344] In the post-heating process, the lower limit of the surface temperature of the recording medium is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher. The upper limit of the surface temperature of the recording medium is preferably 120°C or lower, more preferably 110°C or lower, even more preferably 100°C or lower, particularly preferably 90°C or lower, and even more particularly preferably 80°C or lower.

[0345] It should be noted that the preferred temperature in the above-mentioned primary drying process is different from the preferred temperature in the subsequent heating process.

[0346] 4. Example

[0347] The present invention will now be described in more detail through examples, but the invention is not limited to these examples. Unless otherwise specified, “%” refers to a quality standard.

[0348] 4.1 Determination of dynamic permeability of recording media

[0349] The dynamic permeability of the low-permeability, non-permeable, and permeable substrates used in each example and comparative example was measured using a DPM33 dynamic permeability tester (manufactured by emco). As recording media, "GLOSS PW" and "CAST 73" cast paper were used for the low-permeability substrate, "PET50A" and "PP WHITE" films were used for the non-permeable substrate, and "55PW" high-grade paper was used for the permeable substrate. The measurement results are recorded in Table 1 below.

[0350] It should be noted that in Table 1 below, "value after 60 seconds" is 10log of the following formula (1). 10 The value of (A / A0), "value after 10 seconds" is 10log of the following formula (1). 10 The (A / A0) value is obtained by adding water for 60 seconds and then measuring it after 10 seconds. "PET50A" is used as the reference substrate for the following formula (1).

[0351] In addition, "contact angle" refers to the static contact angle, which is determined by the static drop method according to JIS R 3257 (Test method for wettability of substrate glass surface).

[0352] 10log 10 (A / A0)<-5[dB]···Equation (1)

[0353] (A0: Water permeability on the reference substrate after 60 seconds. A: Water permeability on the target substrate after 60 seconds.)

[0354] [Table 1]

[0355] Table 1:

[0356] Substrate class High grade paper Cast paper Cast paper Film Film Substrate name 55 PW Gloss PW Cast 73 PET 50A PP white Permeability High Low Low Non Non Value after 60 seconds [dB] -7 -9 -10 0 0 Value after 10 seconds [dB] -4 -1 -1 0 0 Contact angle [°] 116 106 94 88 91

[0357] As shown in Table 1 above, the permeability of non-permeable substrates tends to be lower after both 60 seconds and 10 seconds. On the other hand, the permeability of low-permeability substrates tends to be lower after 10 seconds, but higher after 60 seconds than that of permeable substrates.

[0358] 4.2 Preparation of the treatment solution

[0359] The components were placed in a container to form the composition shown in Table 2 below. After mixing and stirring with an electromagnetic stirrer for 2 hours, the mixture was filtered through a membrane filter with a pore size of 5 μm to obtain the treatment solutions (A1-A4, B1-B3) involved in each embodiment and comparative example. The values ​​in Table 2 below are all expressed as mass %, and pure water was added to make the total mass of the treatment solution reach 100% by mass.

[0360] 4.3 Preparation of each composition

[0361] The components of each composition were placed in a container to form the compositions shown in Table 3 below. After mixing and stirring with an electromagnetic stirrer for 2 hours, the mixture was filtered through a 5 μm pore size membrane filter to obtain ink composition (C1), white ink composition (W1), and transparent ink composition (CL1). All values ​​in Table 3 below represent mass %, and pure water was added to bring the total mass of the treatment solution to 100% by mass. It should be noted that the values ​​for resin particles and wax composition in Table 3 below are the total liquid volume values ​​without conversion to resin solids content.

[0362] It should be noted that, although not recorded in the table, the calcium formate content in treatment solution B1 was set to 10% by mass (0.77 mol / kg). Otherwise, it was prepared in the same way as treatment solution B1. As a result, the calcium formate was not fully dissolved and was not suitable for treatment solution.

[0363] It should be noted that the cyan pigment in the ink composition and the white pigment in the white ink composition are prepared in advance and the pigment dispersion is used as described below.

[0364] <Cyan Pigment Dispersion>

[0365] First, 7.5 parts by mass of acrylic acid-acrylate copolymer (weight average molecular weight: 25,000, acid value: 180) as a resin dispersant were added to 160.5 parts by mass of ion-exchanged water containing 2 parts by mass of 30% ammonia solution (neutralizing agent) and dissolved. Then, 30 parts by mass of CI Pigment Blue 15:3 as a cyan pigment were added, and the mixture was dispersed for 10 hours using a ball mill with zirconia beads. Next, the mixture was centrifuged and filtered to remove coarse particles and impurities, adjusting the cyan pigment concentration to 15% by mass to obtain a cyan pigment dispersion. The particle size of the cyan pigment at this point was 100 nm (average particle size).

[0366] <White pigment dispersion>

[0367] First, 4 parts by mass of acrylic acid-acrylate copolymer (weight average molecular weight: 25,000, acid value: 18) as a resin dispersant were added to 155 parts by mass of ion-exchanged water containing 0.1 parts by mass of 30% ammonia solution (neutralizing agent) and dissolved. Then, 40 parts by mass of titanium dioxide (CI Pigment White 6) as a white pigment were added, and the mixture was dispersed for 10 hours using a ball mill with zirconia beads. Next, the mixture was centrifuged and filtered to remove coarse particles and other impurities, adjusting the concentration of the white pigment to 20% by mass to obtain a white pigment dispersion. The particle size of the white pigment was 350 nm on average.

[0368] [Table 2]

[0369] Table 2:

[0370]

[0371] [Table 3]

[0372] Table 3:

[0373]

[0374] Supplementary explanations are provided for the records in Tables 2 and 3 above.

[0375] (Flocculant)

[0376] • Calcium nitrate tetrahydrate: Its solubility (hereinafter referred to as "solubility") in 100g of water at 20℃ is 129g / 100g water.

[0377] • Calcium bromide: Solubility is 143 g / 100 g water.

[0378] Calcium formate: solubility is 16.6 g / 100g water.

[0379] Calcium propionate: Solubility is 10 g / 100 g water.

[0380] (pigment)

[0381] • White pigment (titanium oxide): CI Pigment White 6

[0382] • Cyan pigment (PB 15:3): CI pigment blue 15:3

[0383] (surfactant)

[0384] BYK348: A silicone surfactant, manufactured by BYK-Chemie, a Japanese company.

[0385] (chelating agent)

[0386] ·EDTA: ethylenediaminetetraacetic acid

[0387] (Resin particles)

[0388] ·JONCRYL 631: Styrene-based acrylic resin, a trade name manufactured by BASF.

[0389] (wax)

[0390] HITEC E-6500: Polyethylene wax, a trade name manufactured by Toho Chemical Industry Co., Ltd.

[0391] It should be noted that "mol / kg" in Table 2 above refers to the number of moles of coagulant relative to the total mass [kg] of the treated liquid.

[0392] 4.4 Record the experiment

[0393] The ink assembly, comprising the above-obtained processing liquid, ink composition, white ink composition, and transparent ink composition, was filled into a printing press (a modified version of the "SurePress L-4533AW" manufactured by Seiko Epson), and printing was performed under the conditions described below, based on the descriptions in Tables 4 to 8.

[0394] It should be noted that in each embodiment, the ink pack filled in the printing press includes at least one processing liquid selected from A1 to A4 and at least one processing liquid selected from B1 to B3, and the processing liquid used is selected according to the type of recording medium. On the other hand, in Comparative Example 1, the processing liquid in the ink pack filled in the printing press is only A1, and in Comparative Example 2, the processing liquid in the ink pack filled in the printing press is only B1.

[0395] [Recording conditions]

[0396] • Printing press: A modified version of the “SurePress L-4533AW”.

[0397] • Resolution: 1200×1200dpi. Using this as the base resolution, the number of droplets per pixel was adjusted to achieve the same adhesion amount as in each example.

[0398] • Printed Pattern: When printing for evaluations of ink adhesion, graininess, rubbing resistance, and color development, a solid pattern is used. When printing for evaluations of text, text printing is used. It should be noted that "solid pattern" refers to the prescribed pattern recorded for evaluation purposes.

[0399] • Processing fluid conditions: Use the conditions described in Tables 4 to 8 below.

[0400] • Ink composition conditions: The mass per drop (Iw) is set at 5 ng. Additionally, the adhesion amount is set at 6 mg / inch in the Duty test.2 In the medium-duty trial, the concentration was set at 4 mg / inch. 2 .

[0401] • White ink composition conditions: The mass per drop (Iw) is set at 10 ng. Additionally, the adhesion rate is set at 13 mg / inch. 2 .

[0402] • Transparent ink composition conditions: The mass per drop (Iw) is set at 5 ng. Additionally, the adhesion amount is set at 1 mg / inch. 2 .

[0403] • Number of scans: once. Furthermore, in Examples 13 and 14, it is 1+1=2 scans.

[0404] • First drying temperature: No intentional heating. Alternatively, in Example 11, a pressure plate heater was used for heating to achieve the temperatures shown in the table.

[0405] • Post-heating temperature: 70℃.

[0406] • Recording medium: The substances listed in Table 1 above and Tables 4 to 8 below.

[0407] • Simultaneous dripping of ink composition and treatment solution.

[0408] [Table 4]

[0409]

[0410] [Table 5]

[0411]

[0412] [Table 6]

[0413]

[0414] [Table 7]

[0415]

[0416] [Table 8]

[0417] Table 8

[0418]

[0419] 4.5 Evaluation Methods

[0420] 4.5.1 Inkability

[0421] Print solid patterns under the conditions described in “4.4 Record Test” above, and visually observe the printed matter. Evaluate the results under the following judgment conditions.

[0422] (judgment condition)

[0423] A: It absorbs ink well.

[0424] B: Slightly poor ink adhesion (there are several areas on the substrate of the recording medium that are not filled with ink).

[0425] C: Poor ink adhesion (there are many areas on the substrate of the recording medium that are not filled with ink).

[0426] 4.5.2 Particle size

[0427] Print solid patterns under the conditions described in "4.4 Record Test" above, and visually inspect the printed matter. Evaluate the results under the following criteria. It should be noted that particle size can be caused by excessive ink reaction or by insufficient reaction leading to uneven exudation.

[0428] (judgment condition)

[0429] A: No particle size.

[0430] B: Granularity exists, but it has no impact.

[0431] C: Significant granularity.

[0432] 4.5.3 Text

[0433] Under the conditions described in "4.4 Record Test" above, print text and visually inspect the printed material. Evaluate the print under the following criteria. A score of B or higher indicates good quality.

[0434] (judgment condition)

[0435] A: The characters are clearly defined and readable.

[0436] B: The character lines are not continuous, but it has no effect and is readable.

[0437] C: The character lines are discontinuous and cannot be read.

[0438] 4.5.4 Abrasion resistance

[0439] After printing the solid pattern under the conditions described in "4.4 Record Test" above, dry it in a constant temperature bath at 70°C for 2 minutes, and then leave it at room temperature overnight. Then, cut the printed solid pattern into 30×200mm rectangles, and visually observe the degree of ink peeling after 50 rubs using a vibratory abrasion tester (load 500g) on ​​plain weave fabric. Evaluate the results under the following criteria: A score of B or higher indicates good performance.

[0440] (judgment condition)

[0441] A: No peeling.

[0442] B: Less than 50% of the evaluated area has peeling.

[0443] C: More than 50% of the area being evaluated has peeled off.

[0444] 4.5.5 Color Developing Properties

[0445] Print a solid pattern under the conditions described in "4.4 Record Test" above, measure the OD value of the print, and evaluate it under the following criteria. If the value is B or higher, it is considered good.

[0446] (judgment condition)

[0447] A: A high OD value indicates vivid colors that can be visually observed.

[0448] B: Although the OD value is not very high, the colors appear vivid to the eye.

[0449] C: Low OD value.

[0450] 4.6 Evaluation Results

[0451] The evaluation results are shown in Tables 4-8 above.

[0452] As shown in Tables 4-8 above, in various embodiments of the ink group, recording apparatus, and recording method, excellent image quality (inkability and graininess) and abrasion resistance are obtained in both low-permeability substrates and non-permeability substrates. The ink group comprises an aqueous ink composition containing pigments, a first processing liquid containing a coagulant, and a second processing liquid containing a coagulant. The coagulant content of the first processing liquid is 0.60 mol / kg or more, and the coagulant content of the second processing liquid is less than 0.60 mol / kg. The first processing liquid is used together with the ink composition to record on a recording medium that is a low-permeability substrate, and the second processing liquid is used together with the ink composition to record on a recording medium that is a non-permeability substrate.

[0453] A recording device records onto a recording medium, the recording device comprising the ink group, and performs: a first recording using an ink composition and a first processing liquid to record onto a recording medium serving as a low-permeability substrate, and a second recording using an ink composition and a second processing liquid to record onto a recording medium serving as a non-permeable substrate; and

[0454] The recording method uses the ink group to record to a recording medium. The recording method includes the following steps: selecting a processing liquid for recording from a first processing liquid and a second processing liquid; attaching the selected processing liquid to the recording medium; and attaching the ink composition to the recording medium. The recording method is any one of the following: a first record in which the selected processing liquid is the first processing liquid and the recording medium is a low-permeability substrate, or a second record in which the selected processing liquid is the second processing liquid and the recording medium is a non-permeable substrate.

[0455] The comparison between Example 1 and Comparative Examples 1 and 2 shows that, in the absence of the first and second processing liquids described above, excellent image quality (ink adhesion and graininess) and abrasion resistance cannot be obtained in recordings on both low-permeability and non-permeability substrates.

[0456] The comparison between Example 1 and Comparative Example 3 shows that when the coagulant content of the first processing liquid in the ink group is not 0.60 mol / kg or more, excellent image quality (grain and text) cannot be obtained in either low-permeability substrates or non-permeability substrates.

[0457] The results of Examples 1 and 2 demonstrate that excellent image quality and abrasion resistance can be obtained on recording media in various low-permeability and non-permeability substrates.

[0458] The results of Examples 1, 3, 4, 10, and 12 demonstrate that excellent image quality and abrasion resistance can be achieved through a wide range of coagulant contents and various coagulants.

[0459] The results of Examples 1 and 5 show that if the droplets of the treatment liquid adhere in a regular pattern, the image quality tends to be superior.

[0460] The results of Examples 1, 6, and 8 show that if the amount of the treatment liquid adheres to two or more different ink compositions, it tends to have better image quality and abrasion resistance.

[0461] The results of Examples 1 and 7 show that if the maximum time difference between the adhesion of the treatment liquid and the adhesion of the ink composition is within a specified time, there is a tendency for the image quality to be better.

[0462] The results of Examples 1 and 9 show that if a process is included to further adhere the resin-containing transparent ink composition to the recording medium, it tends to have even better abrasion resistance.

[0463] The results of Examples 1 and 11 show that there is a tendency for better image quality when no intentional heating is performed during a single drying process.

[0464] The results of Examples 13 and 14 show that even when using white ink compositions, excellent image quality and abrasion resistance can be obtained in recordings on both low-permeability and non-permeability substrates.

[0465] The results of Examples 2 and 15 show that if the droplet volume of the processing liquid when recording to a non-permeable substrate is less than that when recording to a permeable substrate, the image quality when recording to a non-permeable substrate is better.

[0466] The following content is derived from the above implementation method.

[0467] One aspect of the ink group includes an aqueous ink composition containing pigments, a first processing liquid containing a coagulant, and a second processing liquid containing a coagulant.

[0468] The coagulant content of the first treatment solution is above 0.60 mol / kg.

[0469] The coagulant content of the second treatment solution is less than 0.60 mol / kg.

[0470] The first processing liquid, together with the ink composition, is used to record onto a recording medium that serves as a low-permeability substrate.

[0471] The second processing liquid, together with the ink composition, is used to record onto a recording medium that serves as a non-permeable substrate.

[0472] In one aspect of the aforementioned ink group,

[0473] Optionally, the low-permeability substrate satisfies the following formula (1) when the permeability of water dropped onto the low-permeability substrate for 60 seconds is set to A, and the non-permeable substrate does not satisfy the following formula (1) when the permeability of water dropped onto the non-permeable substrate for 60 seconds is set to A.

[0474] 10log 10 (A / A0)<-5[dB]···Equation (1)

[0475] (A0: Permeability of water after 60 seconds on the reference substrate; A: Permeability of water after 60 seconds on the target substrate.)

[0476] In any of the above ink groups

[0477] Optionally, the coagulant contained in the first treatment solution has a solubility of more than 100g in 100g of water at 20°C, and the coagulant contained in the second treatment solution has a solubility of less than 100g in 100g of water at 20°C.

[0478] In any of the above ink groups

[0479] Optionally, the coagulant contained in the first treatment solution and the coagulant contained in the second treatment solution are polyvalent metal salts.

[0480] In any of the above ink groups

[0481] Optionally, the first processing liquid can be further used together with the ink composition to record onto a recording medium that serves as a permeable substrate.

[0482] In any of the above ink groups

[0483] Optionally, the ink composition is a non-white ink composition, and further comprises a white ink composition.

[0484] One aspect of the recording device records to the recording medium.

[0485] The above-described recording device includes an ink set according to any of the above aspects.

[0486] The above-mentioned recording device performs:

[0487] A first recording is performed using the ink composition and the first processing liquid on a recording medium that serves as a low-permeability substrate; and

[0488] A second recording is performed using the ink composition and the second processing liquid on a recording medium that serves as a non-permeable substrate.

[0489] In one aspect of the aforementioned recording device,

[0490] Optionally, in both the first and second records, the processing liquid is applied to the recording medium using an inkjet printing method.

[0491] In the first record, the treatment liquid is sprayed according to the first droplet mass and allowed to adhere to the recording medium.

[0492] In the second record, a treatment liquid is sprayed out according to a second droplet mass smaller than that of the first droplet and adhered to the recording medium.

[0493] One aspect of the recording method is to record to a recording medium using any of the ink groups described above.

[0494] The above recording method includes the following steps:

[0495] Select the processing solution for recording from the first processing solution and the second processing solution;

[0496] The selected treatment solution is applied to the recording medium; and

[0497] The ink composition is then applied to the recording medium.

[0498] The above recording method is any one of the following: a first record in which the selected processing liquid is the first processing liquid and the recording medium is a low-permeability substrate; or a second record in which the selected processing liquid is the second processing liquid and the recording medium is a non-permeable substrate.

[0499] In one aspect of the above-mentioned recording method,

[0500] Optionally, the amount of the treatment solution adhering is 1.5 mg / inch. 2 the following.

[0501] In any of the above-mentioned recording methods,

[0502] Optionally, the ink composition and the processing liquid are applied to the recording medium by inkjet printing.

[0503] In any of the above-mentioned recording methods,

[0504] Optionally, the droplets of the treatment liquid are made to adhere in a regular pattern.

[0505] In any of the above-mentioned recording methods,

[0506] Optionally, in the same scan, the processing liquid and the ink composition are sprayed and overlapped onto the recording medium, with the maximum time difference between the adhesion of the processing liquid and the adhesion of the ink composition being within 1 second.

[0507] In any of the above-mentioned recording methods,

[0508] Optionally, the amount of the treatment liquid adhering to the ink composition may have two or more variations depending on the amount of the ink composition adhering to the ink.

[0509] In any of the above-mentioned recording methods,

[0510] Optionally, the recording resolution of the processing liquid is 1200×1200 dpi or higher.

[0511] In any of the above-mentioned recording methods,

[0512] Optionally, the above recording method includes a step of further adhering the resin-containing transparent ink composition to the recording medium.

[0513] This invention is not limited to the above-described embodiments and can have various modifications. For example, this invention includes configurations that are substantially the same as those described in the embodiments, such as configurations with the same function, method, and result, or configurations with the same purpose and effect. Furthermore, this invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Additionally, this invention includes configurations that can achieve the same effect or purpose as those described in the embodiments. Furthermore, this invention includes configurations obtained by adding known techniques to the configurations described in the embodiments.

Claims

1. An ink set, characterized in that, have: A water-based ink composition containing pigments, a first treatment liquid containing a coagulant, and a second treatment liquid containing a coagulant. The coagulant content of the first treatment solution is above 0.60 mol / kg. The coagulant content of the second treatment solution is less than 0.60 mol / kg. The first processing liquid, together with the ink composition, is used to record onto a recording medium that serves as a low-permeability substrate. The second processing liquid, together with the ink composition, is used to record onto a recording medium that serves as a non-permeable substrate. The low-permeability substrate satisfies the following formula (1) when the permeability of water dropped onto the low-permeability substrate for 60 seconds is set as A, and the non-permeable substrate does not satisfy the following formula (1) when the permeability of water dropped onto the non-permeable substrate for 60 seconds is set as A. 10log 10 (A / A0) < -5 [dB] Equation (1) In the formula, A0: the permeability of water after 60 seconds on the reference substrate; A: the permeability of water after 60 seconds on the target substrate, wherein the reference substrate is a polyethylene terephthalate membrane.

2. The ink assembly according to claim 1, characterized in that, For the low-permeability substrate, the left side of equation (1) is 10log 10 (A / A0) is above -20 [dB] and below -5 [dB].

3. The ink set according to claim 1, characterized in that, The coagulant in the first treatment solution has a solubility of more than 100g in 100g of water at 20℃, while the coagulant in the second treatment solution has a solubility of less than 100g in 100g of water at 20℃.

4. The ink set according to claim 1, characterized in that, The coagulant contained in the first treatment solution and the coagulant contained in the second treatment solution are polyvalent metal salts.

5. The ink set according to claim 1, characterized in that, The first processing liquid is further used together with the ink composition to record onto a recording medium that serves as a permeable substrate.

6. The ink set according to claim 1, characterized in that, The ink composition is a non-white ink composition, and further includes a white ink composition.

7. A recording apparatus for recording on a recording medium, characterized in that, The recording device comprises the ink group according to any one of claims 1 to 6. The recording device performs: The first recording involves using the ink composition and the first processing liquid to record on a recording medium that serves as a low-permeability substrate. as well as The second recording involves using the ink composition and the second processing liquid to record on a recording medium that serves as a non-permeable substrate.

8. The recording device according to claim 7, characterized in that, In both the first and second records, the processing liquid is applied to the recording medium using an inkjet printing method. In the first record, the treatment liquid is sprayed according to the first droplet mass and allowed to adhere to the recording medium. In the second record, a treatment liquid is sprayed out according to a second droplet mass smaller than that of the first droplet and adhered to the recording medium.

9. A recording method, characterized in that, Recording is performed on the recording medium using the ink set according to any one of claims 1 to 6. The recording method includes the following steps: The process of selecting a processing solution for recording from the first processing solution and the second processing solution; The process of applying the selected treatment solution to the recording medium; and The process of applying the ink composition to the recording medium. The recording method is either a first record or a second record, wherein the first record is a record in which the selected processing liquid is the first processing liquid and the recording medium is a low-permeability substrate, and the second record is a record in which the selected processing liquid is the second processing liquid and the recording medium is a non-permeable substrate.

10. The recording method according to claim 9, characterized in that, The amount of the treatment solution adhering to the surface is 1.5 mg / inch. 2 the following.

11. The recording method according to claim 9, characterized in that, The ink composition and the processing liquid are adhered to the recording medium by inkjet printing.

12. The recording method according to claim 11, characterized in that, The droplets of the treatment liquid adhere in a regular pattern.

13. The recording method according to claim 11, characterized in that, The processing liquid and the ink composition are sprayed onto the recording medium in the same scan and overlapped, with the maximum time difference between the adhesion of the processing liquid and the adhesion of the ink composition being within 1 second.

14. The recording method according to claim 11, characterized in that, The amount of the treatment liquid adhering to the ink composition can have two or more variations depending on the amount of ink adhering to the ink composition.

15. The recording method according to claim 11, characterized in that, The recording resolution of the processing liquid is above 1200×1200 dpi.

16. The recording method according to claim 9, characterized in that, The process includes the following step: further adhering the resin-containing transparent ink composition to the recording medium.

Images