Image recording material and method for manufacturing the same, and laminate body and method for manufacturing the same

Abstract

To provide: an image recorded material excellent in lamination strength when a base material for lamination is laminated on an image; a method for producing the image recorded material; a laminate; and a method for manufacturing the laminate.SOLUTION: The method for producing the image recorded material includes: a step of preparing a pretreatment liquid containing water and an aggregating agent which is at least one selected from the group consisting of an organic acid, an organic acid salt, a polyvalent metal compound, and a metal complex; a step of preparing a first ink containing a first pigment, a first resin, water, and a surfactant 1, in which a content of the surfactant 1 is 0.01% by mass to 0.8% by mass with respect to a total amount of the first ink; a step of preparing a second ink containing a second pigment, a second resin, water, and a surfactant 2, in which a content of the surfactant 2 is 0.8% by mass to 5% by mass with respect to a total amount of the second ink; and an image recording step of applying the pretreatment liquid, the first ink, and the second ink in this order onto an impermeable base material to record an image; wherein in the image recording step, the image is recorded under a condition that an overlapping region in which a region to which the pretreatment liquid is applied, a region to which the first ink is applied, and a region to which the second ink is applied overlap each other in plan view is generated, and a ratio of a total applied mass of the first resin and the second resin per unit area to an applied mass of the aggregating agent per unit area is 16.0 or more and 30.0 or less in the overlapping region. The image recorded material, the laminate, and a method for manufacturing the laminate are also described.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to an image recording material and a method for manufacturing the same, as well as a laminate and a method for manufacturing the same. [Background technology]

[0002] In recent years, research has been conducted on techniques for recording images using ink and a pretreatment solution (also called a reaction solution, etc.) containing a coagulant that aggregates the components in the ink.

[0003] For example, Patent Document 1 discloses an inkjet recording method that reduces the odor of the reactant and allows for the production of high-quality records, comprising a recording step of attaching a reaction solution and one or more inkjet ink compositions to a low-absorbency or non-absorbency recording medium, wherein the reaction solution contains a reactant which is a carboxylic acid or carboxylate salt that reacts with the components of the inkjet ink composition, the inkjet ink composition contains a resin and water, and in the area where the inkjet ink composition is attached on the low-absorbency or non-absorbency recording medium, when the area with the highest amount of resin attached per unit area is defined as 100%, the mass ratio of the amount of resin attached to the amount of reactant attached (resin / reactant) in the area where the amount of resin attached is 20% or more and 100% or less is 1.5 or more and 16 or less, thereby attaching the reaction solution and the inkjet ink composition.

[0004] Furthermore, Patent Document 2 discloses an inkjet recording method for obtaining a recording material with excellent image quality and scratch resistance, comprising: a reaction solution attachment step of attaching a reaction solution containing a flocculant that aggregates the components of an aqueous ink composition to the recording area of ​​a recording medium; and an ink composition attachment step of ejecting an aqueous ink composition containing a pigment dispersion including a surface treatment pigment and water from an inkjet head to attach to the recording area of ​​the recording medium, wherein the recording area has a region in which the amount of aqueous ink composition attached is 2 to 20 times the amount of reaction solution attached. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2015-217591 [Patent Document 2] Japanese Patent Publication No. 2018-165029 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, after recording an image on a non-permeable substrate to obtain an image recording, a laminating substrate may be laminated onto the image on the image recording. In this case, it may be necessary to improve the lamination strength between the image recording and the laminating substrate.

[0007] An object of one aspect of this disclosure is to provide an image recording material comprising an impermeable substrate and an image recorded on the impermeable substrate, wherein the image recording material exhibits excellent lamination strength when a laminating substrate is laminated onto the image, and a method for manufacturing the image recording material that can produce the image recording material. An object of another aspect of the present disclosure is a laminate comprising an image recording and a laminating substrate laminated onto the image of the image recording, wherein the laminate has excellent lamination strength between the image and the laminating substrate, and a method for manufacturing the laminate that can produce the laminate. It is about providing. [Means for solving the problem]

[0008] The following are examples of specific means for solving the problem: <1> A step of preparing a pretreatment solution containing a flocculant, which is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes, and water. A step of preparing a first ink containing a first pigment, a first resin, and water, A step of preparing a second ink containing a second pigment, a second resin, and water, wherein the surface tension is lower than that of the first ink. An image recording process in which a pretreatment solution, a first ink, and a second ink are applied in that order to a non-permeable substrate to record an image, Includes, A method for manufacturing an image recording material, wherein the image recording step is characterized by the following conditions: an overlapping region is created in a plan view where a region to which a pretreatment liquid is applied, a region to which a first ink is applied, and a region to which a second ink is applied, and in the overlapping region, the ratio of the total mass of the first and second resins applied per unit area to the mass of the flocculant applied per unit area is 16.0 or more and 30.0 or less. <2> The above ratio is between 16.0 and 25.0. <1> A method for manufacturing the image recording described above. <3> The content of organic solvents with a boiling point of 220°C or higher relative to the total amount of the first ink is 5% by mass or less. The content of organic solvents with a boiling point of 220°C or higher relative to the total volume of the second ink is 5% by mass or less. <1> or <2> A method for manufacturing the image recording described above. <4> The pretreatment solution contains resin, The first resin contains resin particles, The glass transition temperature of the resin contained in the pretreatment solution is lower than the glass transition temperature of the resin particles contained in the first resin. <1> ~ <3> A method for manufacturing an image recording as described in any one of the following. <5> The first resin contains resin particles, The second resin contains resin particles, Among the resin particles contained in the first resin and the resin particles contained in the second resin, in the overlapping region, when Ta represents the glass transition temperature of the one with a larger applied mass per unit area, and Tb represents the glass transition temperature of the one with a smaller applied mass per unit area, Ta and Tb satisfy the relationship of 0°C ≤ Ta-Tb ≤ 30°C. The method for producing an image recorded material according to any one of <1> to <4>. <6> When A1 represents the viscosity of a mixture obtained by mixing the pretreatment liquid and the first ink, and A2 represents the viscosity of a mixture obtained by mixing the pretreatment liquid and the second ink, A1 and A2 satisfy A1-A2 > 0 mPa·s. The method for producing an image recorded material according to any one of <1> to <3>. <7> A step of obtaining an image recorded material by the method for producing an image recorded material according to any one of <1> to <6>, a step of laminating a laminating substrate on the image-recorded side of the image recorded material to obtain a laminated body, A method for producing a laminated body comprising the above steps. <8> An image recorded material comprising a non-permeable substrate and an image recorded on the non-permeable substrate, wherein the image comprises a pretreatment layer that is in contact with the non-permeable substrate and contains a coagulant, a first layer that is in contact with the pretreatment layer and contains a first pigment and a first resin, and a second layer that is in contact with the first layer and contains a second pigment and a second resin, and the image comprises an overlapping region where the pretreatment layer, the first layer and the second layer overlap in a plan view, the coagulant is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes, in the overlapping region, the first resin per unit area relative to the mass of the coagulant per unit area the ratio of the total mass of the resin and the second resin is 16.0 or more and 30.0 or less. The image recorded material. <9> A laminated body comprising the image recorded material according to <8>, and a laminating substrate laminated on the image of the image recorded material, comprising the above components. The laminated body. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, an image recording material comprising an impermeable substrate and an image recorded on the impermeable substrate is provided, which has excellent lamination strength when a laminating substrate is laminated onto the image, and a method for manufacturing the image recording material that can produce the above image recording material is provided. According to another aspect of the present disclosure, a laminate is provided comprising an image recording and a laminating substrate laminated onto the image of the image recording, wherein the laminate has excellent lamination strength between the image and the laminating substrate, and a method for manufacturing the laminate is provided for manufacturing the laminate. [Modes for carrying out the invention]

[0010] In this disclosure, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. In this disclosure, the amount of each component in the composition means the total amount of any multiple substances present in the composition, unless otherwise specified, if there are multiple substances corresponding to each component in the composition. In the numerical ranges described in stages within this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages, or with the values ​​shown in the examples. In this disclosure, the term "process" includes not only independent processes but also any process that cannot be clearly distinguished from other processes, as long as its intended purpose is achieved. In this disclosure, a preferred combination of embodiments is a more preferred embodiment.

[0011] In this disclosure, "image" means the entire film formed by applying a pretreatment solution, a first ink, and a second ink in that order onto a non-permeable substrate, and "image recording" and "image recording" mean film formation and film formation, respectively. Furthermore, the concept of "image" in this disclosure also includes solid images.

[0012] [Method for manufacturing image recordings] The method for manufacturing an image recording in this disclosure is: A step of preparing a pretreatment solution containing a flocculant, which is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes, and water. A step of preparing a first ink containing a first pigment, a first resin, and water, A step of preparing a second ink containing a second pigment, a second resin, and water, wherein the surface tension is lower than that of the first ink. An image recording process in which a pretreatment solution, a first ink, and a second ink are applied in that order to a non-permeable substrate to record an image, Includes, The image recording process records an image under the following conditions: an overlapping region is created in a plan view where the region to which the pretreatment solution is applied, the region to which the first ink is applied, and the region to which the second ink is applied overlap; and in the overlapping region, the ratio of the total mass of the first and second resins applied per unit area to the mass of the flocculant applied per unit area (hereinafter also referred to as the "mass application ratio [(first resin + second resin) / flocculant]" or "amount application ratio [resin / flocculant]") is 16.0 or more and 30.0 or less.

[0013] According to the method for manufacturing an image recording material of the present disclosure, an image recording material comprising an impermeable substrate and an image recorded on the impermeable substrate can be manufactured, which has excellent lamination strength when a laminating substrate is laminated onto the image. Here, lamination strength refers to the peel strength when separating the laminating substrate from the image recording material in a laminated body formed by the above lamination [i.e., a laminated body having a laminated structure of "laminating substrate / image recording material" (more specifically, a laminated structure of "laminating substrate / image / impermeable substrate")].

[0014] The reason why the above-mentioned effects are achieved by the method for manufacturing image recordings disclosed herein is presumed to be as follows. To improve the lamination strength of a laminated object, it is necessary to first improve the adhesion between the non-permeable substrate and the image, and then improve the adhesion between the image and the laminating substrate. In the image recording step of the method for manufacturing an image recording material of this disclosure, a pretreatment liquid, a first ink, and a second ink are applied to a non-permeable substrate in this order. That is, the pretreatment liquid is applied to the non-permeable substrate, the first ink is applied on the applied pretreatment liquid, and the second ink is applied on the applied first ink. The pretreatment liquid, the first ink, and the second ink are applied under conditions (i.e., application arrangement) in which an overlapping region is created in a plan view where the area to which the pretreatment liquid is applied, the area to which the first ink is applied, and the area to which the second ink is applied overlap. As a result, on the non-permeable substrate, the components of the first ink (mainly the first resin) and the components of the second ink (mainly the second resin) applied on the pretreatment liquid aggregate due to the action of a flocculant component in the pretreatment liquid, and an image is obtained. In this case, it is believed that by having an applied mass ratio [(first resin + second resin) / coagulant] of 30.0 or less in the overlapping region, insufficient aggregation of the first and second resins is suppressed, and the decrease in adhesion between the non-permeable substrate and the image caused by insufficient aggregation is suppressed. Furthermore, in the overlapping region, if the applied mass ratio [(first resin + second resin) / aggregant] is 16.0 or higher, over-aggregation of the first and second resins is suppressed, and surface irregularities and / or variations in image thickness caused by over-aggregation are suppressed. As a result, it is believed that the decrease in adhesion between the image and the laminating substrate caused by surface irregularities and / or variations in image thickness is suppressed. Furthermore, because the surface tension of the second ink is lower than that of the first ink, the wetting spread of the second ink on the first ink is improved in the overlapping region, and as a result, surface irregularities and / or variations in image thickness are suppressed. Consequently, it is believed that the decrease in adhesion between the image and the laminating substrate caused by surface irregularities and / or variations in image thickness is suppressed. As described above, the method for manufacturing an image recording in this disclosure ensures adhesion between the non-permeable substrate and the image, as well as adhesion between the image and the laminating substrate, and as a result, it is believed that lamination strength is ensured.

[0015] The following describes each step that may be included in the method for manufacturing the image recordings disclosed herein.

[0016] <Steps to prepare the pretreatment solution> The step of preparing the pretreatment solution (hereinafter also referred to as the "pretreatment solution preparation step") is the step of preparing a pretreatment solution containing a coagulant which is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes, and water. The pretreatment solution preparation step may simply involve preparing a pre-manufactured pretreatment solution, or it may be a step in manufacturing a pretreatment solution. There are no particular restrictions on the method of producing the pretreatment solution; known methods for mixing each component can be applied.

[0017] (water) The pretreatment solution contains water. The water content is preferably 50% by mass or more, and more preferably 60% by mass or more, relative to the total amount of the pretreatment solution. The upper limit of the water content depends on the amounts of other components, but is preferably 90% by mass or less of the total amount of the pretreatment solution.

[0018] (Flocculant) The pretreatment solution is prepared by adding a flocculant, which is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes. The coagulant is a component that causes the components (e.g., the first ink and the second ink; the same applies hereinafter) in the ink to coagulate.

[0019] -Organic acid- Examples of organic acids include organic compounds that have an acidic group. Examples of acidic groups include phosphate groups, phosphonic acid groups, phosphinic acid groups, sulfate groups, sulfonic acid groups, sulfinic acid groups, and carboxyl groups. From the viewpoint of the ink aggregation rate, the above-mentioned acidic group is preferably a phosphoric acid group or a carboxyl group, and more preferably a carboxyl group. Furthermore, it is preferable that at least a portion of the above-mentioned acidic group is dissociated in the pretreatment solution.

[0020] Preferred organic compounds having a carboxyl group include polyacrylic acid, acetic acid, formic acid, benzoic acid, glycolic acid, malonic acid, malic acid (preferably DL-malic acid), maleic acid, succinic acid, glutaric acid, fumaric acid, citric acid, tartaric acid, phthalic acid, adipic acid, pimelic acid, 4-methylphthalic acid, lactic acid, pyrrolidone carboxylic acid, pyrrone carboxylic acid, pyrrole carboxylic acid, furanic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, pimelic acid, and the like. These compounds may be used individually or in combination of two or more.

[0021] As for organic compounds having a carboxyl group, divalent or higher carboxylic acids (hereinafter also referred to as polyvalent carboxylic acids) are preferred from the viewpoint of ink aggregation rate. As for polycarboxylic acids, Dicarboxylic acids or tricarboxylic acids are preferred. Glutaric acid, malonic acid, succinic acid, adipic acid, pimelic acid, malic acid, maleic acid, fumaric acid, tartaric acid, or citric acid are more preferably used. Glutaric acid, malonic acid, succinic acid, adipic acid, pimelic acid, malic acid, fumaric acid, tartaric acid, or citric acid are more preferably used. Glutaric acid, malonic acid, succinic acid, adipic acid, or pimelic acid are more preferred.

[0022] Organic acids are preferably those with a low pKa (e.g., 1.0 to 5.0). This allows for a reduction in the dispersion stability of particles such as pigments and polymer particles in inks, which are dispersed and stabilized by weakly acidic functional groups such as carboxyl groups, by bringing them into contact with organic acidic compounds with lower pKa values.

[0023] The organic acid is preferably a divalent or trivalent acidic substance that has a low pKa, high solubility in water, and a valency of 2 or higher, and more preferably has a high buffering capacity in a pH range lower than the pKa of the functional group (e.g., carboxyl group) that disperses and stabilizes the particles in the ink.

[0024] -Organic acid salt- Examples of organic acid salts include the salts of the organic acids exemplified above. Examples of organic acid salts include those containing alkaline earth metals from Group 2 of the periodic table (e.g., magnesium, calcium), transition metals from Group 3 of the periodic table (e.g., lanthanum), cations from Group 13 of the periodic table (e.g., aluminum), and lanthanides (e.g., neodymium). As for organic acid salts, organic acid salts containing alkaline earth metals are preferred, and organic acid salts containing calcium (e.g., calcium lactate, calcium acetate, etc.) or organic acid salts containing magnesium (e.g., magnesium lactate, magnesium acetate, etc.) are preferred.

[0025] -Polyvalent metal compounds- Examples of polyvalent metal compounds include salts (excluding organic salts) containing at least one selected from the group consisting of alkaline earth metals of Group 2 of the periodic table (e.g., magnesium, calcium), transition metals of Group 3 of the periodic table (e.g., lanthanum), cations from Group 13 of the periodic table (e.g., aluminum), and lanthanides (e.g., neodymium). Suitable polyvalent metal compounds include nitrates, chlorides, or thiocyanates. Particularly preferred polyvalent metal compounds are calcium or magnesium salts of nitric acid, calcium chloride, magnesium chloride, or calcium or magnesium salts of thiocyanate. It is preferable that the polyvalent metal compound dissociates into polyvalent metal ions and counterions in the pretreatment solution, at least a portion of which is present.

[0026] -Metal complex- As for the metal complex, a metal complex containing at least one element selected from the group consisting of zirconium, aluminum, and titanium is preferred. As for the metal complex, a metal complex comprising at least one selected from the group consisting of acetate, acetylacetonate, methylacetoacetate, ethylacetoacetate, octylene glycolate, butoxyacetylacetonate, lactate, lactate ammonium salt, and triethanolamine as a ligand is preferred.

[0027] Various metal complexes are commercially available, and in this disclosure, commercially available metal complexes may be used. In addition, various organic ligands, in particular various polydentate ligands that can form metal chelate catalysts, are commercially available. Therefore, metal complexes prepared by combining commercially available organic ligands with metals may also be used.

[0028] There are no particular restrictions on the amount of flocculant contained. From the viewpoint of ink aggregation rate, the content of the coagulant relative to the total amount of pretreatment solution is preferably 0.1% to 40% by mass, more preferably 0.1% to 30% by mass, even more preferably 1% to 20% by mass, and particularly preferably 1% to 10% by mass.

[0029] (resin) The pretreatment solution preferably contains at least one type of resin. If the pretreatment solution contains resin, the adhesion of the image will be further improved.

[0030] If the pretreatment solution contains a resin, the glass transition temperature (Tg) of the resin contained in the pretreatment solution is preferably 0°C or higher, more preferably 10°C or higher, even more preferably 20°C or higher, and even more preferably 30°C or higher. If the pretreatment solution contains a resin, the glass transition temperature (Tg) of the resin contained in the pretreatment solution is preferably 120°C or lower, more preferably 100°C or lower, and even more preferably The temperature is 80°C or lower, and more preferably 70°C or lower.

[0031] In this disclosure, the glass transition temperature of the resin refers to the value measured using differential scanning calorimetry (DSC). The specific measurement of the glass transition temperature shall be carried out in accordance with the methods described in JIS K 7121 (1987) or JIS K 6240 (2011). In this disclosure, the glass transition temperature is the extrapolation glass transition onset temperature (hereinafter sometimes referred to as Tig). The method for measuring the glass transition temperature will be explained in more detail. To determine the glass transition temperature, the apparatus is held at a temperature approximately 50°C lower than the expected glass transition temperature of the resin until it stabilizes. Then, the temperature is heated at a heating rate of 20°C / min to approximately 30°C higher than the temperature at which the glass transition is completed, and a differential thermal analysis (DTA) curve or digital sensor cell (DSC) curve is created. The extrapolation glass transition onset temperature (Tig), i.e., the glass transition temperature in this disclosure, is determined as the temperature at the intersection of a straight line drawn by extending the low-temperature baseline of the DTA curve or DSC curve toward the high-temperature side, and a tangent line drawn at the point where the slope of the curve representing the stepwise transition portion of the glass transition is maximum.

[0032] If the pretreatment solution contains two or more types of resin, the glass transition temperature (Tg) of the resins in the pretreatment solution represents the weighted average of the glass transition temperatures of the individual resins.

[0033] Examples of resins that may be included in the pretreatment solution include acrylic resin, polyester resin, polyolefin resin, polyurethane resin, polyurea resin, polyamide resin, polycarbonate resin, and polystyrene resin. The resin that may be contained in the pretreatment solution preferably contains a polyester resin or an acrylic resin, and more preferably contains a polyester resin.

[0034] In this disclosure, "acrylic resin" means a polymer (homopolymer or copolymer) of raw material monomers that includes at least one selected from the group consisting of acrylic acid, derivatives of acrylic acid (e.g., acrylic acid esters, etc.), methacrylic acid, and derivatives of methacrylic acid (e.g., methacrylic acid esters, etc.). In this disclosure, polyester resin means a polymer compound containing ester bonds in its main chain. Examples of polyester resins include polycondensates of polycarboxylic acids (e.g., dicarboxylic acids) and polyalcohols (e.g., diols). In this disclosure, polyolefin resin means a polymer (homopolymer or copolymer) of raw material monomers containing olefins. Examples of polyolefin resins include polymers of one type of olefin, copolymers of two or more types of olefins, copolymers of one or more types of olefins and one or more other monomers. Examples of olefins include α-olefins having 2 to 30 carbon atoms. In this disclosure, polyurethane resin means a polymer compound containing urethane bonds. In this disclosure, polyurea resin means a polymer compound containing urea bonds. In this disclosure, polyamide resin means a polymer compound containing amide bonds. In this disclosure, polycarbonate resin means a polymer compound containing carbonate bonds. In this disclosure, polystyrene resin means a polymer of raw material monomers containing styrene.

[0035] The resin that may be contained in the pretreatment solution may be a water-soluble resin or a water-insoluble resin, but a water-insoluble resin is preferred.

[0036] In this disclosure, "water-soluble" means a substance whose solubility in 100g of water at 25°C is 1g or more. Preferably, "water-soluble" means a substance whose solubility in 100g of water at 25°C is 3g or more (more preferably 10g or more). In this disclosure, "water-insoluble" means a property in which the amount of substance that dissolves in 100g of water at 25°C is less than 1g. Preferably, "water-insoluble" means a property in which the amount of substance that dissolves in 100g of water at 25°C is less than 0.5g.

[0037] The pretreatment solution preferably contains resin particles. The resin particles are preferably made of a water-insoluble resin. Preferably, the resin particles are acrylic resin particles, polyester resin particles, a mixture of acrylic resin particles and polyester resin particles, or composite particles containing acrylic resin and polyester resin. As for the resin particles, those similar to the resin particles that may be included in the first ink, as described later in the section "Steps for preparing the first ink," are also preferable.

[0038] The weight-average molecular weight (Mw) of the resin in the resin particles is preferably 1,000 to 300,000, more preferably 2,000 to 200,000, and even more preferably 5,000 to 100,000.

[0039] In this disclosure, unless otherwise specified, weight-average molecular weight (Mw) refers to the value measured by gel permeation chromatography (GPC). Gel permeation chromatography (GPC) measurements were performed using an HLC®-8020GPC (Tosoh Corporation) as the measuring instrument, with three TSKgel® Super Multipore HZ-H columns (4.6 mm ID × 15 cm, Tosoh Corporation) and THF (tetrahydrofuran) as the eluent. The measurement conditions were a sample concentration of 0.45% by mass, a flow rate of 0.35 mL / min, a sample injection volume of 10 μL, and a measurement temperature of 40°C, using an RI detector. The calibration curve will be prepared using eight samples from Tosoh Corporation's "Standard Samples TSK standard, polystyrene": "F-40", "F-20", "F-4", "F-1", "A-5000", "A-2500", "A-1000", and "n-propylbenzene".

[0040] The volume-average particle size of the resin particles is preferably 1 nm to 300 nm, more preferably 3 nm to 200 nm, and even more preferably 5 nm to 150 nm.

[0041] When preparing the pretreatment solution, commercially available aqueous dispersions of resin particles may be used. Commercially available aqueous dispersions of resin particles include Pesresin A124GP, Pesresin A645GH, Pesresin A615GE, Pesresin A520 (all manufactured by Takamatsu Oil & Fat Co., Ltd.), Eastek1100, Eastek1200 (both manufactured by Eastman Chemical Co., Ltd.), Pluscoat RZ570, Pluscoat Z687, Pluscoat Z565, Pluscoat RZ570, Pluscoat Z690 (all manufactured by Go-o Chemical Industry Co., Ltd.), Byronal MD1200 (manufactured by Toyobo Co., Ltd.), EM57DOC (manufactured by Daicel Finechem Co., Ltd.), and others.

[0042] If the pretreatment solution contains resin particles, the content of resin particles relative to the total amount of the pretreatment solution is preferably 0.5% to 30% by mass, more preferably 1% to 20% by mass, and particularly preferably 1% to 15% by mass.

[0043] (Water-soluble organic solvent) The pretreatment solution preferably contains at least one water-soluble organic solvent. Any known water-soluble organic solvent can be used without any particular restrictions. Examples of water-soluble organic solvents include glycerin, 1,2,6-hexanetriol, trimethylolpropane, alkanediols (e.g., ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-butene-1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, 1,2-octanediol, 1,2-hexanediol, 1,2-pentanediol, 4-methyl-1,2-pentanediol, etc.), and polyalkylene glycols (e.g., diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, dipropylene glycol, polyoxyethylene polyoxypropylene glycol, etc.) and other polyhydric alcohols; Polyhydric alcohol ethers such as polyalkylene glycol ethers (e.g., diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, tripropylene glycol monoalkyl ether, polyoxypropylene glyceryl ether, etc.); Alkyl alcohols having 1 to 4 carbon atoms, glycol ethers, 2-pyrrolidone, and N-methyl-2-pyrrolidone; These are some examples. In particular, from the viewpoint of suppressing the transfer of components, polyhydric alcohols or polyhydric alcohol ethers are preferred, and alkanediols, polyalkylene glycols, or polyalkylene glycol ethers are more preferred.

[0044] If the pretreatment solution contains a water-soluble organic solvent, the content of the water-soluble organic solvent relative to the total amount of the pretreatment solution is preferably 0.5% to 30% by mass, more preferably 1% to 20% by mass, and particularly preferably 1% to 15% by mass.

[0045] As for water-soluble organic solvents that can be contained in the pretreatment solution, water-soluble organic solvents with a boiling point of less than 220°C are also preferred. From the viewpoint of the drying properties of the pretreatment solution, it is preferable that the pretreatment solution does not contain organic solvents with a boiling point of 220°C or higher, or that the content of organic solvents with a boiling point of 220°C or higher is 5% by mass or less (more preferably 3% by mass or less, and even more preferably 1% by mass or less) of the total amount of the pretreatment solution. For specific examples of water-soluble organic solvents with a boiling point below 220°C and organic solvents with a boiling point above 220°C, please refer to the section "Preparation of the First Ink" described later.

[0046] (Other ingredients) The pretreatment solution may contain other components not listed above, if necessary. Other components that may be contained in the pretreatment solution include known additives such as surfactants, solid wetting agents, silicate compounds (e.g., colloidal silica), inorganic salts, anti-fading agents, emulsifying stabilizers, penetration enhancers, ultraviolet absorbers, preservatives, antifungal agents, pH adjusters, viscosity adjusters, rust inhibitors, chelating agents, and water-soluble polymer compounds other than water-soluble cationic polymers (e.g., water-soluble polymer compounds described in paragraphs 0026 to 0080 of Japanese Patent Application Publication No. 2013-001854). Other components that may be included in the pretreatment solution can also be seen from the components that may be included in the first ink, as described later.

[0047] (Physical properties of the pretreatment solution) From the viewpoint of ink aggregation rate, the pH of the pretreatment solution at 25°C is preferably 0.1 to 3.5. If the pH of the pretreatment solution is 0.1 or higher, the roughness of the non-permeable substrate is further reduced, and the image The adhesion between the parts will be further improved. When the pH of the pretreatment solution is 3.5 or lower, the aggregation rate is further improved, the coalescence of ink dots on the surface of the non-permeable substrate is further suppressed, and the graininess of the image is further reduced. The pH of the pretreatment solution at 25°C is more preferably between 0.2 and 2.0. The measurement conditions for the pH of the pretreatment solution at 25°C are the same as those for the pH of the ink at 25°C as described above.

[0048] If the pretreatment solution contains a coagulant, the viscosity of the pretreatment solution is preferably in the range of 0.5 mPa·s to 10 mPa·s, and more preferably in the range of 1 mPa·s to 5 mPa·s, from the viewpoint of the ink coagulation rate.

[0049] Unless otherwise specified, the viscosity in this disclosure is the value measured using a viscometer at 25°C. For example, a VISCOMETER TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.) is used as the viscometer.

[0050] The surface tension of the pretreatment solution is preferably 60 mN / m or less, more preferably 20 mN / m to 50 mN / m, and even more preferably 30 mN / m to 45 mN / m.

[0051] Unless otherwise specified, the surface tensions in this disclosure are values ​​measured at a temperature of 25°C. Surface tension is measured using, for example, an Automatic Surface Tentiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

[0052] <Preparation of the first ink> The process of preparing the first ink (hereinafter also referred to as the "first ink preparation process") is the process of preparing the first ink containing a first pigment, a first resin, and water. The first ink preparation step may simply be a step of preparing a pre-manufactured first ink, or it may be a step of manufacturing the first ink. There are no particular restrictions on the method for manufacturing the first ink; known methods for mixing each component can be applied.

[0053] (water) The first ink contains water. The water content is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more, relative to the total amount of the first ink. The upper limit of the water content depends on the amounts of other components, but is preferably 90% by mass or less, and more preferably 80% by mass or less, relative to the total amount of the first ink.

[0054] (First Pigment) The first ink contains the first pigment. The term "first pigment" refers to all pigment components contained in the first ink (i.e., one or more pigments). There are no particular restrictions on the first pigment; it can be either an organic or inorganic pigment.

[0055] Examples of organic pigments include azo pigments and polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, diketopyrrolopyrrole pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments). Examples include pigments, dye chelates, nitro pigments, nitroso pigments, aniline black, etc. Examples of inorganic pigments include white inorganic pigments, iron oxide, barium yellow, cadmium red, chromium yellow, and carbon black. Preferred embodiments of white inorganic pigments will be described later. Examples of the first pigment include the pigments described in paragraphs 0096 to 0100 of Japanese Patent Publication No. 2009-241586.

[0056] The first ink, which contains a chromatic pigment or a black pigment as the first pigment, can be used, for example, as a color ink (e.g., cyan ink, magenta ink, yellow ink, etc.) or a black ink.

[0057] Furthermore, when the first ink includes a white pigment (for example, a white inorganic pigment) as the first pigment, it can also be used as, for example, a white ink (hereinafter also referred to as "white ink"). Furthermore, if the first pigment includes a white pigment and a pigment of a color other than white, the first ink can also be used as an ink in which a chromatic color is added to the white color.

[0058] Examples of white inorganic pigments include titanium dioxide (TiO2), barium sulfate, calcium carbonate, aluminum hydroxide, silica, zinc oxide, zinc sulfide, mica, talc, and pearl. Among the white inorganic pigments, titanium dioxide, barium sulfate, calcium carbonate, or zinc oxide are preferred, with titanium dioxide being more preferred.

[0059] The average primary particle size of white inorganic pigments is, for example, 150 nm to 400 nm. When the average primary particle diameter is 150 nm or larger, the opacity is further improved. Here, opacity refers to the property of covering and concealing the underlying surface with an image (e.g., a white image). When the average primary particle diameter is 400 nm or less, the ejection performance of the first ink is further improved. The average primary particle size of the white inorganic pigment is preferably 250 nm to 350 nm, and more preferably 250 nm to 300 nm.

[0060] The average primary particle size of white inorganic pigments is measured using a transmission electron microscope (TEM). A JEOL Ltd. 1200EX transmission electron microscope can be used for this measurement. Specifically, a Cu200 mesh (manufactured by JEOL Ltd.) with a carbon film attached is dropped with ink diluted 1,000 times and dried. Then, the circular equivalent diameter of 300 independent, non-overlapping particles is measured from an image magnified 100,000 times using TEM, and the average of the obtained measurements is defined as the average primary particle diameter.

[0061] The content of the first pigment is preferably 1% to 20% by mass, more preferably 1% to 15% by mass, and even more preferably 1% to 10% by mass, relative to the total amount of the first ink.

[0062] (First resin) The first ink contains the first resin. Here, the first resin refers to all the resin components contained in the first ink (i.e., one or more types of resin). In the image recording process described later, when the first resin in the first ink comes into contact with the flocculant in the pretreatment solution on a non-permeable substrate, the resin particles in the first ink aggregate. This improves the adhesion of the image.

[0063] There are no particular restrictions on the first resin, but preferably acrylic resin, polyester resin, It is a polyurethane resin or a polyolefin resin.

[0064] The content of the first resin relative to the total amount of the first ink is preferably 1% to 30% by mass, more preferably 2% to 20% by mass, even more preferably 2% to 15% by mass, and even more preferably 2% to 10% by mass.

[0065] Examples of the first resin include, specifically, a pigment dispersion resin for dispersing the first pigment, resin particles which are particles made of resin, and so on.

[0066] -Pigment-dispersed resin- The first resin may include a pigment dispersion resin. When the first resin includes a pigment dispersion resin, the first ink contains a resin-coated pigment having a structure in which at least a portion of the surface of the first pigment is coated with the pigment dispersion resin. A water-insoluble resin is preferred as the pigment dispersion resin.

[0067] The pigment dispersion resin is preferably an acrylic resin. Examples of pigment dispersion resins include those described in International Publication No. 2013 / 180074, Japanese Patent Publication No. 5863600, Japanese Unexamined Patent Publication No. 2018-28080, Japanese Unexamined Patent Publication No. 2017-149906, and Japanese Unexamined Patent Publication No. 2016-193981. Pigment dispersion resins are also referred to as "resin dispersants," etc. Furthermore, as a combination of the first pigment and the pigment dispersion resin, a resin-coated pigment in which the pigment is coated with a crosslinked water-soluble resin, as described in, for example, Japanese Patent Publication No. 5404669, may be used. In this case, the resin-coated pigment can be prepared, for example, by using an acrylic resin having a carboxyl group as the water-soluble resin and a bifunctional or more epoxy compound as the crosslinking agent.

[0068] From the viewpoint of adsorption to pigments, the pigment dispersion resin preferably contains an alicyclic structure or an aromatic cyclic structure, and more preferably contains an aromatic cyclic structure. As for the alicyclic structure, an alicyclic hydrocarbon structure having 5 to 10 carbon atoms is preferred, and a cyclohexane ring structure, dicyclopentanyl ring structure, dicyclopentenyl ring structure, norbornane ring structure, isobornane ring structure, norbornene ring structure, isobornene ring structure, or adamantane ring structure is preferred. The aromatic ring structure is preferably a naphthalene ring or a benzene ring, with a benzene ring being more preferred. The amount of alicyclic or aromatic ring structure is preferably 0.01 mol to 1.5 mol per 100 g of resin contained in the resin particles, and more preferably 0.1 mol to 1 mol.

[0069] From the viewpoint of pigment dispersion performance, it is preferable that the pigment dispersion resin has ionic groups in its structure. The ionic group may be an anionic group or a cationic group, but an anionic group is preferred. The anionic group is not particularly limited, but a carboxyl group, a salt of a carboxyl group, a sulfo group, or a salt of a sulfo group is preferred.

[0070] From the viewpoint of pigment dispersibility and storage stability, the acid value of the resin dispersant is preferably 30 mg KOH / g to 100 mg KOH / g, more preferably 30 mg KOH / g to 85 mg KOH / g, and even more preferably 50 mg KOH / g to 85 mg KOH / g. Here, the acid value is defined as the mass (mg) of KOH required to completely neutralize 1 g of resin, and is measured according to the method described in the JIS standard (JIS K 0070, 1992). That is the case.

[0071] The weight-average molecular weight (Mw) of the pigment-dispersed resin is preferably 30,000 or more, more preferably 30,000 to 150,000, even more preferably 30,000 to 100,000, and even more preferably 30,000 to 80,000.

[0072] When the first resin contains a pigment dispersion resin, the content of the pigment dispersion resin is preferably 1% to 25% by mass, more preferably 1% to 20% by mass, even more preferably 1% to 15% by mass, and even more preferably 1% to 10% by mass, based on the total amount of the first ink.

[0073] When the first resin contains a pigment dispersion resin, the ratio of the pigment dispersion resin (D) to the pigment (P) (i.e., the D / P ratio) is preferably 0.05 to 3, more preferably 0.05 to 2, even more preferably 0.05 to 1, and even more preferably 0.05 to 0.7.

[0074] -Resin particles- The first resin may contain resin particles. Here, the resin particles are distinguished from the pigment-dispersed resins mentioned earlier in that they are particles made of resin. Water-insoluble resins are preferred as the resins that make up the resin particles. When the first resin contains resin particles, the resin particles in the first ink come into contact with the flocculant in the pretreatment solution on a non-permeable substrate, causing the resin particles in the first ink to aggregate and the first ink to thicken. Therefore, when the first resin contains resin particles, the image intensity and adhesion are improved compared to when the first resin does not contain resin particles. Furthermore, when the first resin contains resin particles, the increase in viscosity of the first ink is more suppressed and the decrease in the discharge performance of the first ink is more suppressed compared to when the first resin contains the same mass of water-soluble resin.

[0075] There are no particular restrictions on the glass transition temperature of the resin particles (i.e., the glass transition temperature of the resin in the resin particles). From the viewpoint of further improving image intensity, the glass transition temperature (Tg) of the resin particles is preferably 20°C or higher, more preferably 50°C or higher, and even more preferably 80°C or higher. From the viewpoint of suitability for manufacturing resin particles, the glass transition temperature (Tg) of the resin particles is preferably 150°C or lower, and more preferably 130°C or lower.

[0076] In the method for manufacturing an image recording in this disclosure, from the viewpoint of further improving the adhesion of the image, The pretreatment solution contains resin, The first resin in the first ink contains resin particles. It is preferable that the glass transition temperature of the resin contained in the pretreatment solution is lower than the glass transition temperature of the resin particles contained in the first resin. In this case, the value obtained by subtracting the glass transition temperature of the resin contained in the pretreatment solution from the glass transition temperature of the resin particles contained in the first resin is preferably 20°C or higher, more preferably 30°C or higher, and even more preferably 40°C or higher. There is no particular upper limit to this value, but possible upper limits include, for example, 100°C, 150°C, and 200°C.

[0077] Preferably, the resin particles are acrylic resin particles (hereinafter also referred to as acrylic resin particles), polyester resin particles (hereinafter also referred to as polyester resin particles), polyurethane resin particles (hereinafter also referred to as polyurethane resin particles), or polyolefin These are particles made of polyolefin resin (hereinafter also referred to as polyolefin resin particles).

[0078] From the viewpoint of further improving image adhesion and scratch resistance, the resin particles contained in the first ink preferably include acrylic resin particles. When the resin particles contained in the first ink include acrylic resin particles, the ratio of acrylic resin particles to the total resin particles contained in the first ink is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. If the ratio of acrylic resin particles to the resin particles contained in the first ink is 60% by mass or more, the adhesion of the image is further improved.

[0079] Self-dispersible resin particles are preferred as the resin particles. Examples of self-dispersing resin particles include self-dispersing polymer particles described in paragraphs 0062 to 0076 of Japanese Patent Publication No. 2016-188345 and paragraphs 0109 to 0140 of International Publication No. 2013 / 180074.

[0080] The resin in the resin particles preferably contains an alicyclic structure or an aromatic cyclic structure, and more preferably contains an alicyclic structure. As for the alicyclic structure, an alicyclic hydrocarbon structure having 5 to 10 carbon atoms is preferred, and a cyclohexane ring structure, dicyclopentanyl ring structure, dicyclopentenyl ring structure, norbornane ring structure, isobornane ring structure, norbornene ring structure, isobornene ring structure, or adamantane ring structure is preferred. The aromatic ring structure is preferably a naphthalene ring or a benzene ring, with a benzene ring being more preferred. The amount of alicyclic or aromatic ring structure is preferably 0.01 mol to 1.5 mol per 100 g of resin in the resin particles, and more preferably 0.1 mol to 1 mol.

[0081] In resin particles, it is preferable that the resin has ionic groups in its structure, from the viewpoint of further improving the water dispersibility of the resin particles. The ionic group may be an anionic group or a cationic group, but an anionic group is preferred. The anionic group is not particularly limited, but a carboxyl group, a salt of a carboxyl group, a sulfo group, or a salt of a sulfo group is preferred.

[0082] As resin in resin particles, More preferably, the acrylic resin comprises at least one selected from the group consisting of benzyl (meth)acrylate units, phenoxyethyl (meth)acrylate units, and alicyclic structure-containing (meth)acrylate units, and (meth)acrylic acid units. More preferably, the acrylic resin comprises at least one selected from the group consisting of benzyl (meth)acrylate units, phenoxyethyl (meth)acrylate units, and alicyclic structure-containing (meth)acrylate units, (meth)acrylic acid units, alkyl (meth)acrylate units containing an alkyl group having 1 to 4 carbon atoms, and alkyl (meth)acrylate units containing an alkyl group having 5 to 12 carbon atoms.

[0083] As the alicyclic structure-containing (meth)acrylate, at least one selected from alkyl (meth)acrylates having a cycloalkyl group with 3 to 10 carbon atoms (e.g., cyclohexyl (meth)acrylate), isobornyl (meth)acrylate, adamantyl (meth)acrylate, and dicyclopentanyl (meth)acrylate is preferred. At least one selected from isobornyl (meth)acrylate, adamantyl (meth)acrylate, and dicyclopentanyl (meth)acrylate is more preferred.

[0084] The acid value of the resin in the resin particles is preferably 25 mg KOH / g to 100 mg KOH / g, more preferably 30 mg KOH / g to 90 mg KOH / g, and even more preferably 35 mg KOH / g to 80 mg KOH / g, from the viewpoint of self-dispersibility and aggregation during image recording.

[0085] The molecular weight of the resin in the resin particles is preferably 1,000 to 300,000, more preferably 2,000 to 200,000, and even more preferably 5,000 to 100,000. The weight-average molecular weight is measured by gel permeation chromatography (GPC). Details of GPC are as previously described.

[0086] The volume-average particle size of the resin particles is preferably 1 nm to 200 nm, more preferably 3 nm to 200 nm, and even more preferably 5 nm to 50 nm.

[0087] If the first ink contains resin particles, the content of resin particles relative to the total amount of the first ink is preferably 1% to 25% by mass, more preferably 2% to 20% by mass, even more preferably 2% to 15% by mass, and still more preferably 2% to 10% by mass.

[0088] (Water-soluble organic solvents with a boiling point below 220°C) The first ink preferably contains at least one water-soluble organic solvent with a boiling point of less than 220°C. This improves the lamination strength of image recordings. In this disclosure, boiling point means boiling point at 1 atmosphere (101325 Pa).

[0089] Examples of water-soluble organic solvents with a boiling point below 220°C include 1,2-propanediol (also known as propylene glycol; PG) (boiling point 188°C), 1,3-propanediol (boiling point 213°C), propylene glycol monomethyl ether (boiling point 121°C), ethylene glycol (boiling point 197°C), ethylene glycol monomethyl ether (boiling point 124°C), propylene glycol monoethyl ether (boiling point 133°C), ethylene glycol monoethyl ether (boiling point 135°C), and propylene glycol monopropyl ether ( Examples include ethylene glycol monopropyl ether (boiling point 151°C), propylene glycol monobutyl ether (boiling point 170°C), ethylene glycol monobutyl ether (boiling point 171°C), 2-ethyl-1-hexanol (boiling point 187°C), dipropylene glycol monomethyl ether (boiling point 188°C), diethylene glycol dimethyl ether (boiling point 162°C), diethylene glycol diethyl ether (boiling point 188°C), and dipropylene glycol dimethyl ether (boiling point 175°C).

[0090] If the first ink contains a water-soluble organic solvent with a boiling point of less than 220°C, the content of the water-soluble organic solvent with a boiling point of less than 220°C is preferably 1% to 50% by mass, more preferably 5% to 40% by mass, even more preferably 10% to 40% by mass, and even more preferably 15% to 35% by mass, based on the total amount of ink.

[0091] (Organic solvents with a boiling point of 220°C or higher) The content of organic solvents with a boiling point of 220°C or higher (hereinafter also referred to as "high-boiling point solvents") in the first ink is preferably 5% by mass or less. This further improves the lamination strength and image adhesion of the image recording material. Here, "the content of organic solvents with a boiling point of 220°C or higher in the first ink is 5% by mass or less" means that the first ink does not contain organic solvents with a boiling point of 220°C or higher (i.e., the first ink This means that the content of organic solvents with a boiling point of 220°C or higher in the ink is 0% by mass, or, if present, the content of organic solvents with a boiling point of 220°C or higher is 5% by mass or less relative to the total amount of the first ink. The content of organic solvents with a boiling point of 220°C or higher in the first ink is more preferably 3% by mass or less, even more preferably 2% by mass or less, even more preferably 1% by mass or less, and even more preferably 0% by mass.

[0092] As will be described later, the meaning of "the content of organic solvents with a boiling point of 220°C or higher in the second ink is 5% by mass or less" is the same as "the content of organic solvents with a boiling point of 220°C or higher in the first ink is 5% by mass or less," and the preferred content of high-boiling-point solvents in the second ink is the same as the preferred content of high-boiling-point solvents in the first ink.

[0093] Examples of organic solvents with a boiling point of 220°C or higher include glycerin (boiling point 290°C), 1,2-hexanediol (HDO) (boiling point 223°C), diethylene glycol (boiling point 245°C), diethylene glycol monobutyl ether (boiling point 230°C), triethylene glycol (boiling point 285°C), dipropylene glycol (boiling point 232°C), tripropylene glycol (boiling point 267°C), trimethylolpropane (boiling point 295°C), 2-pyrrolidone (boiling point 245°C), tripropylene glycol monomethyl ether (boiling point 243°C), triethylene glycol monomethyl ether (boiling point 248°C), and the like.

[0094] (Surfactants) The first ink may contain at least one surfactant. Examples of surfactants include nonionic surfactants, cationic surfactants, anionic surfactants, and betaine surfactants.

[0095] A preferred surfactant is an acetylene glycol-based surfactant, which is a type of nonionic surfactant. As an acetylene glycol-based surfactant, for example, an acetylene glycol-based surfactant described in paragraphs 0070-0080 of International Publication No. 2017 / 149917 can be used. Examples of acetylene glycol-based surfactants include Polyalkylene oxide adduct of 2,4,7,9-tetramethyl-5-decine-4,7-diol (preferably polyethylene oxide adduct), Polyalkylene oxide adduct of 3,6-dimethyl-4-octin-3,6-diol (preferably polyethylene oxide adduct), Polyalkylene oxide adduct of 2,5,8,11-tetramethyl-6-dodecine-5,8-diol (preferably polyethylene oxide adduct), Examples include polyalkylene oxide adducts of 2,5-dimethyl-3-hexyn-2,5-diol (preferably polyethylene oxide adducts). Commercially available acetylene glycol-based surfactants include the Surfinol series (e.g., Surfinol 420, Surfinol 440, Surfinol 465, Surfinol 485), Olfin series (e.g., Olfin E1010, Olfin E1020), and Dynol series (e.g., Dynol 604) manufactured by Air Products Co., Ltd. or Nisshin Chemical Industry Co., Ltd.; and Acetyleneol, etc., manufactured by Kawaken Fine Chemical Co., Ltd. Commercially available acetylene glycol-based surfactants are also supplied by companies such as Dow Chemical and General Aniline.

[0096] As surfactants, the compounds listed as surfactants in Japanese Patent Publication No. 59-157636, pages 37-38 and Research Disclosure No. 308119 (1989) are included. Other examples include fluorine (alkyl fluoride) surfactants, silicone surfactants, etc., as described in Japanese Patent Publication Nos. 2003-322926, 2004-325707, and 2004-309806.

[0097] If the first ink contains a surfactant, the amount of surfactant in the first ink is adjusted as appropriate, taking into consideration the surface tension of the first ink. The surfactant content in the first ink is preferably 0.01% to 5% by mass, more preferably 0.05% to 3% by mass, and even more preferably 0.1% to 2% by mass, based on the total amount of the first ink.

[0098] (Silicate compounds) The first ink may contain at least one silicate compound. If the first ink contains a silicate compound, the ejection stability of the first ink from the inkjet head can be further improved. As the silicate compound, for example, the compounds described in paragraphs 0058 to 0075 of Japanese Patent No. 5430316 can be used. As for silicate compounds, Silicates (e.g., sodium silicate, potassium silicate, calcium silicate, magnesium silicate, ammonium silicate, etc.) or anhydrous silicic acid (silica) are preferred. Silica is more preferred, Colloidal silica is even more preferable. Commercially available colloidal silica can be used. Specific examples of commercially available products include Snowtex S, Snowtex XS, Snowtex 20, Snowtex 30, Snowtex 40, Snowtex N, Snowtex C, and Snowtex O (all manufactured by Nissan Chemical Corporation).

[0099] The silicate compound content in the first ink is preferably 0.0001% to 1% by mass, more preferably 0.0005% to 0.5% by mass, even more preferably 0.001% to 0.5% by mass, and even more preferably 0.01% to 0.3% by mass, relative to the total amount of the first ink.

[0100] (Other ingredients) The first ink may contain other components besides those listed above. Other known additives include, for example, urea, urea derivatives, waxes, colorfastness inhibitors, emulsifying stabilizers, penetration enhancers, UV absorbers, preservatives, fungicides, pH adjusters, defoamers, viscosity modifiers, dispersion stabilizers, and chelating agents.

[0101] (Preferred physical properties of the first ink) The viscosity of the first ink (at 25°C) is preferably 1.2 mPa·s or more and 15.0 mPa·s or less, more preferably 2 mPa·s or more and less than 13 mPa·s, and preferably 2.5 mPa·s or more and less than 10 mPa·s.

[0102] The surface tension of the first ink (at 25°C) is preferably 25 mN / m to 50 mN / m, more preferably 30 mN / m to 45 mN / m, and even more preferably 30 mN / m to 40 mN / m.

[0103] The pH of the first ink at 25°C is preferably pH 6 to 11, more preferably pH 7 to 10, and even more preferably pH 7 to 9. The pH of the first ink at 25°C is measured using a commercially available pH meter.

[0104] <Preparing the second ink> The process of preparing the second ink (hereinafter also referred to as the "second ink preparation process") is a process of preparing a second ink containing a second pigment, a second resin, and water, and having a surface tension lower than that of the first ink. The second ink preparation step may simply be a step of preparing a pre-manufactured second ink, or it may be a step of manufacturing the second ink.

[0105] The second ink is the same as the first ink, except that its surface tension is lower than that of the first ink, and the preferred embodiment of the second ink is the same as the preferred embodiment of the first ink.

[0106] Specific examples and preferred embodiments of the second pigment contained in the second ink are the same as those of the first pigment contained in the first ink. The hue of the second pigment is preferably different from the hue of the first pigment. Furthermore, it is preferable that the hue of the second ink is different from the hue of the first ink.

[0107] One specific embodiment of the method for manufacturing an image recording in this disclosure is: The hue of the first ink is a hue other than white (preferably a chromatic color or black; for example, cyan, magenta, yellow, black, etc.). This embodiment is characterized in that the hue of the second ink is white (see the examples described below). In this embodiment, it is preferable that the first pigment contained in the first ink is a chromatic pigment and / or a black pigment, and the second pigment contained in the second ink is a white pigment. In this embodiment, for example, a transparent substrate is used as the impermeable substrate, and a colored image (i.e., a chromatic image or a black image; for example, a pattern image such as characters or figures) is recorded on the impermeable substrate using a first ink. Then, a white image (e.g., a solid color image) is recorded on the impermeable substrate on which the colored image is recorded, so as to cover the colored image. In this case, when observed from the non-image-recorded side of the impermeable substrate (i.e., the side where no image is recorded), the colored image recorded with the first ink against the white image recorded with the second ink can be seen through the impermeable substrate. On the other hand, when observed from the image-recorded side of the impermeable substrate (i.e., the side where an image is recorded), the colored image and the impermeable substrate are obscured by the white image recorded with the second ink, making it difficult to see the colored image and the impermeable substrate. In this embodiment, the area of ​​the white image created by the second ink tends to be larger than the area of ​​the colored image created by the first ink in order to cover the colored image created by the first ink. As a result, in this embodiment, the effect of suppressing surface irregularities and / or variations in image thickness (i.e., the effect of the surface tension of the second ink being lower than that of the first ink, and the effect of the applied mass ratio [(first resin + second resin) / coagulant] being 16.0 or higher) is more effectively exhibited, and the laminate strength is further improved.

[0108] The above embodiments may also include, for example, a method in which a multi-colored image is recorded by applying a plurality of colored inks (e.g., four types: cyan ink, magenta ink, yellow ink, and black ink) to a region on which a pretreatment liquid for an impermeable substrate has been applied, and then a white image is recorded by applying a second white ink to cover this multi-colored image. In this case, the relationship between all of the plurality of colored inks and the second white ink does not necessarily have to satisfy the conditions of the method for manufacturing an image recording material of the present disclosure; it is sufficient that the relationship between at least one of the plurality of colored inks and the second white ink satisfies the conditions of the method for manufacturing an image recording material of the present disclosure. In this case, among the plurality of colored inks, the colored ink that satisfies the conditions of the method for manufacturing an image recording material of the present disclosure corresponds to the first ink.

[0109] The content of high-boiling-point solvents (i.e., organic solvents with a boiling point of 220°C or higher) in the second ink is also, It is preferable that the amount be 5% by mass or less. This further improves the lamination strength of the image recording material and the adhesion of the image. From the viewpoint of further improving the lamination strength and image adhesion of the image recording material, it is more preferable that the content of an organic solvent with a boiling point of 220°C or higher relative to the total amount of the first ink is 5% by mass or less, and the content of an organic solvent with a boiling point of 220°C or higher relative to the total amount of the second ink is 5% by mass or less.

[0110] (Surface tension difference [1st ink - 2nd ink]) As mentioned above, the second ink has a lower surface tension than the first ink. As mentioned above, the surface tension of both the first and second inks refers to values ​​measured under a temperature of 25°C. An example of the surface tension measuring device is also described above. In other words, the difference between the surface tension of the first ink and the surface tension of the second ink (hereinafter also referred to as "surface tension difference [first ink - second ink]" or simply "surface tension difference") is greater than 0 mN / m. This improves the wetting and spreading properties of the second ink on the first ink applied to the non-permeable substrate, suppressing surface irregularities and / or variations in image thickness. As a result, the adhesion between the image and the laminating substrate is improved, and the lamination strength of the laminate is enhanced. The surface tension difference [first ink - second ink] is preferably 2.0 mN / m or more, more preferably 3.0 mN / m or more, and even more preferably 4.0 mN / m or more, from the viewpoint of further improving the lamination strength. There is no particular upper limit on the surface tension difference [first ink - second ink], but the upper limit is, for example, 10.0 mN / m.

[0111] Specific examples and preferred embodiments of the second resin contained in the second ink are the same as those of the first resin contained in the first ink. For example, the second resin preferably contains resin particles. This improves the adhesion between the layer made of the second ink (hereinafter also referred to as the "second ink layer") and the layer made of the first ink (hereinafter also referred to as the "first ink layer") and / or the layer made of the pretreatment solution (hereinafter also referred to as the "pretreatment layer"), and as a result, the lamination strength is further improved.

[0112] (Glass transition temperature difference (Ta-Tb)) A preferred embodiment of the method for manufacturing an image recording material of the present disclosure is one in which the first resin contains resin particles and the second resin also contains resin particles. In this preferred embodiment, among the resin particles contained in the first resin and the resin particles contained in the second resin, in the overlapping region (i.e., the overlapping region where the region to which the pretreatment liquid is applied, the region to which the first ink is applied, and the region to which the second ink is applied overlap in a plan view), if the glass transition temperature of the one with a larger mass applied per unit area is denoted as Ta and the glass transition temperature of the one with a smaller mass applied per unit area is denoted as Tb, then it is preferable that Ta and Tb satisfy the relationship 0°C ≤ Ta - Tb ≤ 30°C. The condition "0℃ ≤ Ta - Tb" (i.e., Tb ≤ Ta) improves the overall film strength of the image (i.e., an image with a layer structure of second ink layer / first ink layer / pretreatment layer), resulting in improved lamination strength. The condition "Ta-Tb ≤ 30℃" (i.e., "Ta-Tb" is 30℃ or less) improves the adhesion between the second ink layer and the first ink layer, resulting in improved lamination strength. "Ta-Tb" is preferably at a temperature of 25°C or lower, and more preferably at a temperature of 20°C or lower.

[0113] (Mixture viscosity difference (A1-A2)) A preferred embodiment of the method for manufacturing an image recording in this disclosure is one in which, when the viscosity of the mixture obtained by mixing the pretreatment liquid and the first ink is A1 (hereinafter also referred to as "mixture viscosity A1"), and the viscosity of the mixture obtained by mixing the pretreatment liquid and the second ink is A2 (hereinafter also referred to as "mixture viscosity A2"), A1 and A2 satisfy A1-A2>0mPa·s. When A1-A2 > 0 mPa·s is satisfied, the wettability and spreadability of the second ink applied to the first ink is improved, and as a result, surface irregularities and / or variations in image thickness are further suppressed. Consequently, the adhesion between the image and the laminating substrate is improved, and the lamination strength is further improved.

[0114] From the viewpoint of further improving the lamination strength, "A1-A2" is preferably 10 mPa·s or higher, more preferably 20 mPa·s or higher, and even more preferably 25 mPa·s or higher. There is no particular upper limit for "A1-A2," but as an upper limit, for example, 50 mPa·s or less is preferred, and 40 mPa·s or less is even more preferred.

[0115] Here, the viscosity A1 of the mixture refers to the value measured as follows: The pretreatment solution and the first ink are mixed at a liquid temperature of 25°C in a ratio such that the mass ratio of the pretreatment solution to the first ink (i.e., mass ratio [pretreatment solution / first ink]) is 0.1. The viscosity of the resulting mixture is measured at a liquid temperature of 25°C within 30 minutes of the completion of mixing of the flocculant and the first ink. Viscosity is measured using a viscometer, such as the VISCOMETER TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.). The viscosity of mixture A2 refers to the value measured in the same manner as the viscosity of mixture A1, except that the first ink was replaced with the second ink.

[0116] <Image recording process> The image recording process involves applying a pretreatment solution, a first ink, and a second ink in that order to a non-permeable substrate to record an image. In the image recording process, the pretreatment solution, the first ink, and the second ink are applied in this order to record an image, under conditions that create an overlapping region in a plan view where the area to which the pretreatment solution is applied, the area to which the first ink is applied, and the area to which the second ink is applied overlap (i.e., application arrangement), and under conditions that the ratio of the total mass of the first and second resins applied per unit area to the mass of the flocculant applied per unit area in the overlapping region (i.e., application mass ratio [(first resin + second resin) / flocculant]) is between 16.0 and 30.0 (i.e., application amount). The image recording process will be described in detail below.

[0117] (Order of application of pretreatment solution, first ink, and second ink) In the image recording process, a pretreatment solution, a first ink, and a second ink are applied to a non-permeable substrate in that order. Specifically, in the image recording process, a pretreatment solution is applied to a non-permeable substrate, a first ink is applied to the applied pretreatment solution, and a second ink is applied to the applied first ink. On a non-permeable substrate, the coagulant component in the pretreatment solution coagulates the components of the first ink (e.g., the first resin) applied to the pretreatment solution, and also coagulates the components of the second ink (e.g., the second resin) applied to the first ink via the first ink. This results in the formation of an image on a non-permeable substrate having a layer structure of "second ink layer / first ink layer / pretreatment layer ( / non-permeable substrate)". Here, the pretreatment layer, first ink layer, and second ink layer refer to the layer derived from the pretreatment solution, the layer derived from the first ink, and the layer derived from the second ink, respectively.

[0118] The first ink may be applied to a pre-treated solution that has been heated and dried (preferred conditions will be described later). Alternatively, it may be applied to a pre-treatment solution that has not been heated or dried. From the viewpoint of suppressing bleeding and other issues, it is preferable that the first ink be applied on a pre-treated solution that has been heated and dried. Preferred conditions for heating and drying the pre-treated solution will be described later.

[0119] The second ink may be applied to the first ink after it has been heat-dried (preferred conditions will be described later), or it may be applied to the first ink that has not been heat-dried. Even when the second ink is applied to the first ink which has not been heat-dried, bleeding and color mixing are suppressed. This is because, at the time the second ink is applied, the first ink has already become thicker due to the action of the pretreatment solution. From the viewpoint of suppressing bleeding and improving the efficiency of image recording, the image recording process is preferably a process in which a pretreatment solution is applied to a non-permeable substrate and heated and dried, and then a first ink and a second ink are applied in this order onto the heated and dried pretreatment solution.

[0120] (Arrangement of pretreatment solution, first ink, and second ink) In the image recording process, the pretreatment solution, the first ink, and the second ink are applied under conditions (i.e., application arrangement) where the areas to which the pretreatment solution is applied, the areas to which the first ink is applied, and the areas to which the second ink is applied overlap in a plan view, and an image is recorded. In the image recording process, the pretreatment solution, the first ink, and the second ink may be applied under conditions (i.e., application arrangement) that create overlapping regions and regions that do not overlap. For example, a patterned first ink layer may be formed by applying the first ink in a patterned manner to an area to which a pretreatment solution has been applied, and then a second ink layer may be formed by applying the second ink (for example, in a solid color) to an area that spans the first ink layer and an area other than the first ink layer (for example, an area that covers the entire first ink layer and its surroundings). In this case, the area where the first ink layer exists corresponds to the "overlapping area" described above, and the area where the first ink layer does not exist but the second ink layer exists, and the area where neither the first nor the second ink layer exists, correspond to the "area other than the overlapping area" described above.

[0121] (Amounts of pretreatment solution, first ink, and second ink applied) In the image recording process, in the overlapping region, the pretreatment solution, the first ink, and the second ink are applied under conditions (i.e., application amount) such that the ratio of the total applied mass of the first and second resins per unit area to the applied mass of the flocculant per unit area (i.e., application mass ratio [(first resin + second resin) / flocculant]) is between 16.0 and 30.0. As mentioned above, by having an application mass ratio [(first resin + second resin) / aggregant] of 16.0 or higher in the overlapping region, over-aggregation of the first and second resins is suppressed in the overlapping region, and surface irregularities (i.e., the surface of the second ink layer) and / or variations in image thickness caused by over-aggregation are suppressed. As a result, the adhesion between the image and the laminating substrate is improved, and the lamination strength is improved. As mentioned above, by keeping the mass ratio of the first resin and the second resin in the overlapping region [(first resin + second resin) / coagulant] below 30.0, insufficient aggregation of the first and second resins in the overlapping region is suppressed. As a result, the adhesion between the non-permeable substrate and the image is improved, and the lamination strength is enhanced.

[0122] The mass ratio applied in the overlapping region [(first resin + second resin) / flocculant] is calculated based on the amount of flocculant applied per unit area in the overlapping region, the amount of first resin applied per unit area in the overlapping region, and the amount of second resin applied per unit area in the overlapping region. Mass of flocculant applied per unit area in the overlapping region (unit: g / m²) 2 This is calculated, for example, based on the amount of pretreatment solution applied per unit area in the overlapping region and the amount of coagulant (mass%) relative to the total amount of pretreatment solution. Mass of the first resin applied per unit area in the overlapping region (unit: g / m²) 2 This is calculated, for example, based on the amount of first ink applied per unit area in the overlapping region and the content (mass%) of first resin relative to the total amount of first ink. Mass of the second resin applied per unit area in the overlapping region (unit: g / m²) 2 This is calculated, for example, based on the amount of second ink applied per unit area in the overlapping region and the content (mass%) of the second resin relative to the total amount of second ink.

[0123] From the viewpoint of further improving the laminate strength, the mass ratio of the additive [(first resin + second resin) / flocculant] is preferably 16.0 to 25.0, and more preferably 16.0 to 20.0. Furthermore, from the viewpoint of further improving the laminate strength, the lower limit of the imparting mass ratio [(first resin + second resin) / flocculant] is preferably 16.1, and more preferably 16.2.

[0124] Mass of flocculant applied per unit area in the overlapping region (unit: g / m²) 2), preferably 0.040 to 0.100, more preferably 0.045 to 0.075. The applied mass of the pretreatment liquid per unit area in the overlapping region (unit: g / m 2 ), preferably 1.0 to 2.0, more preferably 1.2 to 1.8.

[0125] Total applied mass of the first resin and the second resin per unit area in the overlapping region (unit: g / m 2 ), preferably 1.00 to 2.50, more preferably 1.00 to 2.00. Total applied mass of the first ink and the second ink per unit area in the overlapping region (unit: g / m 2 ), preferably 14.0 to 30.0, more preferably 14.5 to 28.0.

[0126] Applied mass of the first resin per unit area in the overlapping region (unit: g / m 2 ), preferably 0.45 to 1.00, more preferably 0.48 to 0.90. Applied mass of the first ink per unit area in the overlapping region (unit: g / m 2 ), preferably 7.0 to 13.0, more preferably 7.0 to 12.0, still more preferably 7.0 to 11.5.

[0127] Applied mass of the second resin per unit area in the overlapping region (unit: g / m 2 ), preferably 0.40 to 2.00, more preferably 0.40 to 1.30, still more preferably 0.50 to 1.10. Applied mass of the second ink per unit area in the overlapping region (unit: g / m 2 ), preferably 7.0 to 20.0, more preferably 7.0 to 18.0, still more preferably 7.0 to 16.0.

[0128] (Non-permeable substrate) In the image recording step, the pretreatment liquid, the first ink, and the second ink are applied onto the non-permeable substrate. A non-permeable substrate refers to a substrate whose water absorption rate (mass %, 24hr.) is less than 0.2 according to the ASTM D570 test method. There are no particular restrictions on the non-permeable substrate, but a resin substrate is preferred. There are no particular restrictions on the resin substrate; for example, a thermoplastic resin substrate can be used. Examples of resin substrates include thermoplastic resins molded into sheet or film shapes. As the resin substrate, a substrate containing polypropylene, polyethylene terephthalate, nylon, polyethylene, or polyimide is preferred.

[0129] The resin substrate may be a transparent resin substrate. Here, "transparent" means that the transmittance of visible light with wavelengths of 400 nm to 700 nm is 80% or higher (preferably 90% or higher). In the embodiment described above, where the hue of the first ink is a hue other than white (preferably a chromatic color or black; for example, cyan, magenta, yellow, black, etc.) and the hue of the second ink is white, if the non-permeable substrate is a transparent resin substrate, the colored image created by the first ink with a white image created by the second ink as the background can be viewed through the non-permeable substrate from the non-image recording side of the non-permeable substrate (i.e., the side on which no image is recorded). The resin substrate may be colored.

[0130] The shape of the resin substrate is not particularly limited, but it is preferably a sheet-shaped resin substrate, and more preferably a sheet-shaped resin substrate that can be formed into a roll by winding, from the viewpoint of productivity of the recording medium. The thickness of the resin substrate is preferably 10 μm to 200 μm, and more preferably 10 μm to 100 μm.

[0131] The resin substrate may be surface-treated to improve its surface energy. Surface treatments include, but are not limited to, corona treatment, plasma treatment, flame treatment, heat treatment, abrasion treatment, light irradiation treatment (UV treatment), and fire treatment.

[0132] (Application of pretreatment solution) In the image recording process, the application of a pretreatment solution to a non-permeable substrate can be carried out by known methods such as coating, inkjet, or immersion. Known coating methods include those using bar coaters (e.g., wire bar coaters), extrusion die coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, gravure coaters, flexo coaters, and the like. Details of the inkjet method will be discussed later.

[0133] Furthermore, in the image recording process, the non-permeable substrate may be heated before applying the pretreatment solution. The heating temperature is preferably 20°C to 50°C for the non-permeable substrate, and more preferably 25°C to 40°C.

[0134] In the image recording process, the pretreatment solution may be heated and dried after it has been applied but before the first ink has been applied. Means for heating and drying the pretreatment liquid include known heating means such as heaters, known air blowing means such as dryers, and means combining these. For example, a method for heating and drying the pretreatment solution is: A method of applying heat from a heater or the like from the side opposite to the surface to which the pretreatment solution for the non-penetrating substrate has been applied. A method of applying warm air or hot air to a surface of a non-penetrating substrate to which a pretreatment solution has been applied. A method of applying heat with an infrared heater to the side of a non-penetrating substrate to which a pretreatment solution has been applied, or from the side opposite to the side to which the pretreatment solution has been applied. A method that combines these multiple methods, These are some examples.

[0135] The heating temperature during the heat drying of the pretreatment solution is preferably 35°C or higher, and more preferably 40°C or higher. There are no particular restrictions on the upper limit of the heating temperature, but a preferred upper limit is 100°C, more preferably 90°C, and even more preferably 70°C. There are no particular restrictions on the heating and drying time, but 0.5 to 60 seconds is preferred, 0.5 to 20 seconds is more preferred, and 0.5 to 10 seconds is particularly preferred.

[0136] (Application of the first ink) In the image recording process, the application of the first ink onto the pretreatment solution (i.e., the pretreatment layer) can be carried out by known methods such as coating, inkjet, or immersion, but is preferably done by the inkjet method. There are no particular restrictions on the ejection method of the first ink in the inkjet method, and any known method may be used, such as a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that utilizes the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electrical signal into an acoustic beam and irradiates the ink to eject the ink using the radiation pressure, and a thermal inkjet (bubble jet®) method that heats the ink to form bubbles and utilizes the resulting pressure. As an inkjet method, in particular, the method described in Japanese Patent Publication No. 54-59936, in which the ink, when subjected to thermal energy, undergoes a rapid volume change, and the force resulting from this state change causes the ink to be ejected from the nozzle, can be effectively utilized. As an inkjet method, the method described in paragraphs 0093 to 0105 of Japanese Patent Publication No. 2003-306623 can also be applied.

[0137] The application of the first ink by the inkjet method is performed by ejecting the first ink from the nozzle of the inkjet head. Inkjet head systems include the shuttle system, which uses a short serial head to scan the recording medium in the width direction while recording, and the line system, which uses a line head in which recording elements are arranged to cover the entire width of one side of the recording medium. In the line method, image recording can be performed across the entire surface of the recording medium by scanning it in a direction intersecting the arrangement direction of the recording elements. The line method eliminates the need for a transport system such as a carriage that scans the short head, which is required in the shuttle method. Furthermore, compared to the shuttle method, the line method eliminates the need for complex scanning control of the carriage movement and the recording medium, as only the recording medium moves. For this reason, the line method enables faster image recording compared to the shuttle method.

[0138] The first ink is preferably applied using an inkjet head having a resolution of 300 dpi or higher (more preferably 600 dpi, and even more preferably 800 dpi). Here, dpi is an abbreviation for dots per inch, and 1 inch is equal to 2.54 cm.

[0139] From the viewpoint of obtaining a high-resolution image, the amount of first ink droplets ejected from the nozzle of the inkjet head is preferably 1 pL (picoliters) to 10 pL, and more preferably 1.5 pL to 6 pL. Furthermore, from the perspective of improving image uniformity and the continuity of continuous gradations, it is also effective to dispense a combination of appropriate amounts of different liquids.

[0140] In the image recording process, the first ink applied to the pretreatment solution (i.e., the pretreatment layer) may be heated and dried, and then the second ink may be applied to the heated and dried first ink. The preferred conditions for heating and drying are the same as the preferred conditions for heating and drying after the application of the second ink, which will be described later. Furthermore, as mentioned above, in the image recording process, the second ink may be applied to the first ink without heating and drying the first ink applied to the pretreatment liquid (i.e., the pretreatment layer). At the step of applying the second ink, the first ink has already thickened due to the action of the coagulant. Therefore.

[0141] Furthermore, the non-permeable substrate may be heated in advance before applying the first ink. This heating may also serve as the heat drying of the pretreatment solution. The heating temperature can be set as appropriate, but it is preferable to set the temperature of the non-permeable substrate to 20°C to 50°C, and more preferably to 25°C to 40°C.

[0142] (Second ink application) In the image recording process, the application of the second ink onto the first ink (i.e., the first ink layer) can also be carried out by known methods such as coating, inkjet, or immersion, but is preferably done by the inkjet method. The inkjet method applicable to the application of the second ink is the same as the inkjet method applicable to the application of the first ink described above, and the preferred embodiments are also the same.

[0143] In the image recording process, after applying the second ink, the first ink (i.e., the first ink layer) and the second ink (i.e., the second ink layer) on the non-permeable substrate may be heat-dried. Means for performing heat drying include known heating means such as heaters, known air blowing means such as dryers, and means combining these. Methods for heat drying include, for example, A method of applying heat from a heater or the like to the side of a non-permeable substrate opposite to the side to which the first and second inks have been applied. A method of applying warm air or hot air to the surface of a non-permeable substrate to which the first ink and the second ink have been applied, a method of applying heat with an infrared heater to the surface of a non-permeable substrate to which the first ink and the second ink have been applied, or from the opposite side of the surface to which the ink has been applied. A method that combines these multiple methods, These are some examples. The heating temperature during heat drying is preferably 55°C or higher, more preferably 60°C or higher, and particularly preferably 65°C or higher. There is no particular upper limit to the heating temperature, but an upper limit of, for example, 100°C is possible, and 90°C is preferred. There are no particular restrictions on the heating and drying time, but 3 to 60 seconds is preferred, 5 to 30 seconds is more preferred, and 5 to 20 seconds is particularly preferred.

[0144] [Method for manufacturing laminated materials] As described above, the method for manufacturing an image recording material according to the present disclosure makes it possible to manufacture an image recording material comprising an impermeable substrate and an image recorded on the impermeable substrate, wherein the image has excellent lamination strength when a laminating substrate is laminated onto the image. Accordingly, the method for manufacturing an image recording material of the present disclosure is suitably used to manufacture a laminate body comprising the image recording material and a laminating substrate laminated to the side of the image recording material on which the image is located. The manufacturing method for the above-mentioned laminated body will be described below.

[0145] The method for manufacturing the laminated body described herein is: The process of obtaining an image recording by the method for manufacturing an image recording as described above in this disclosure, A process of obtaining a laminate by laminating a laminating substrate onto the side of the image recording material on which the image is placed, Includes.

[0146] According to the method for manufacturing a laminate according to this disclosure, a laminate can be manufactured that has excellent lamination strength (i.e., peel strength) between the image recording material and the laminating substrate.

[0147] For the process of obtaining an image recording, refer to the image recording method of this disclosure described above. The process of obtaining a laminate is to laminate a laminating substrate onto the side of the image recording material on which the image is placed to obtain a laminate.

[0148] A resin substrate is preferred as the base material for lamination. The resin substrate is not particularly limited, but examples include a substrate made of a thermoplastic resin. Examples of resin substrates include substrates made by molding thermoplastic resin into a sheet. The resin substrate preferably contains polypropylene, polyethylene terephthalate, nylon, polyethylene, or polyimide.

[0149] The shape of the resin substrate is not particularly limited, but a sheet-like resin substrate is preferred. The thickness of the resin substrate is preferably 10 μm to 200 μm, and more preferably 10 μm to 100 μm.

[0150] In this process, the laminating substrate may be laminated directly onto the side of the image recording material on which the image is placed, or it may be laminated via another layer (e.g., an adhesive layer).

[0151] When laminating a laminating substrate directly onto the side of the image recording material on which the image is placed, the lamination can be carried out by known methods such as heat bonding or heat fusion.

[0152] Furthermore, when laminating a laminate substrate to the side of the image recording object on which the image is placed, the lamination can be carried out, for example, by applying adhesive to the side of the image recording object on which the image is recorded, then placing the laminate substrate on top, and then bonding the image recording object and the laminate substrate together. Furthermore, when laminating the image recording material on the side where the image is placed via an adhesive layer, lamination can also be carried out by methods such as extrusion lamination (i.e., sandwich lamination).

[0153] In the embodiment in which the image recording material described above is laminated to the side on which the image is placed via an adhesive layer, the adhesive layer preferably contains an isocyanate compound. When the adhesive layer contains an isocyanate compound, the adhesion between this adhesive layer and the image ink-derived layer is improved, thereby increasing the lamination strength.

[0154] [Image recordings] The image recordings relating to this disclosure as an example are: The system comprises a non-permeable substrate and an image recorded on the non-permeable substrate. The image includes a pretreatment layer containing a flocculant in contact with a non-permeable substrate, a first layer containing a first pigment and a first resin in contact with the pretreatment layer, and a second layer containing a second pigment and a second resin in contact with the first layer, and includes an overlapping region where the pretreatment layer, the first layer and the second layer overlap in a plan view. The flocculant is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes. In the overlapping region, the ratio of the total mass of the first and second resins per unit area to the mass of the flocculant per unit area is between 16.0 and 30.0.

[0155] The image recording material in this example exhibits excellent lamination strength when a laminating substrate is laminated onto the image.

[0156] The image recording material according to this example is preferably manufactured by the method for manufacturing an image recording material of the present disclosure. In this case, the first layer corresponds to the first ink layer after drying, and the second layer corresponds to the second ink layer after drying. This corresponds to the ink layer. However, solvent may remain in each of the first layer, the second layer, and the pretreatment layer. The preferred embodiments of each component in the image recording material relating to this example are the same as the preferred embodiments of each component described in the section on the method for manufacturing the image recording material of this disclosure.

[0157] [Laminated font] An example of a laminate according to this disclosure comprises the image recording material of this disclosure described above, and a laminating substrate laminated onto the image of the image recording material. The laminated material in this example exhibits excellent lamination strength.

[0158] In the laminate according to this example, the laminating substrate may be directly laminated to the side of the image recording material on which the image is recorded, or it may be laminated via another layer (adhesive layer). The laminate according to this example is preferably manufactured by the method for manufacturing a laminate according to the disclosure. Preferred embodiments of the laminating substrate and adhesive layer are the same as those described in the section on the method for manufacturing the laminate. [Examples]

[0159] The following are examples of the embodiments of this disclosure, but this disclosure is not limited to the following embodiments. In the following, unless otherwise specified, "%" and "parts" refer to mass % and parts by mass, respectively. "Tg" refers to the glass transition temperature, and the Tg difference (Ta-Tb) refers to the difference in glass transition temperatures (Ta-Tb) mentioned above. For the "water" used, ion-exchanged water was employed.

[0160] <Preparation of pretreatment solution> Pretreatment solutions PC1, PC2, and PC3 were prepared as follows.

[0161] (Preparation of pretreatment solution PC1) Pretreatment solution PC1 was prepared by mixing the components with the following composition.

[0162] -Composition of pretreatment solution PC1- • Glutaric acid (manufactured by Fujifilm Wako Pure Chemical Industries; flocculant (organic acid)) …4% by mass • The following resin particles PC1 (Tg 50℃) ...5% by mass as the solid content of the resin particle PC1 below • 1,2-Propanediol (manufactured by Fujifilm Wako Pure Chemical Industries; water-soluble organic solvent) …10% by mass ·water ...The remaining amount will be 100% by mass in total.

[0163] -Preparation of an aqueous dispersion of resin particles PC1 (Tg 50℃)- As an aqueous dispersion of resin particles PC1 (Tg: 50°C), "Pesresin A-520" manufactured by Takamatsu Oil & Fat Co., Ltd. (a 30 mass% aqueous dispersion of polyester resin particles (Tg: 50°C) as resin particles PC1) was prepared.

[0164] (Preparation of Pretreatment Liquid PC2) Glutaric acid as a flocculant was replaced with the same mass of calcium acetate (manufactured by FUJIFILM Wako Pure Chemical Corporation; flocculant (organic acid salt)), and pretreatment liquid PC2 was prepared in the same manner as the preparation of pretreatment liquid PC1.

[0165] (Preparation of Pretreatment Liquid PC3) Pretreatment liquid PC3 containing no resin was prepared in the same manner as the preparation of pretreatment liquid PC1, except that the aqueous dispersion of resin particles PC1 was not used, and the amount of water was adjusted so that the content of glutaric acid was 4 mass%.

[0166] <Preparation of First Ink and Second Ink> Inks A to H as the first ink, and Inks I to M as the second ink were respectively prepared. All of the first inks are cyan inks, and all of the second inks are white inks. Details are shown below.

[0167] (Preparation of Ink A) Ink A as the first ink was prepared as follows.

[0168] - Synthesis of Pigment Dispersion Resin 1 - In a 1000 mL three-necked flask equipped with a stirrer and condenser, 88 g of methyl ethyl ketone was added and heated to 72°C under a nitrogen atmosphere. A solution prepared by dissolving 0.85 g of dimethyl 2,2'-azobisisobutyrate, 60 g of benzyl methacrylate, 10 g of methacrylic acid, and 30 g of methyl methacrylate in 50 g of methyl ethyl ketone was added dropwise over 3 hours. After the dropwise addition was complete, the mixture was reacted for another hour, and then a solution prepared by dissolving 0.42 g of dimethyl 2,2'-azobisisobutyrate in 2 g of methyl ethyl ketone was added. The temperature was raised to 78°C and heated for 4 hours. The resulting reaction solution was reprecipitation twice in a large excess of hexane, and the precipitated resin was dried. In this way, 96 g of pigment dispersion resin 1, which is a benzyl methacrylate / methyl methacrylate / methacrylic acid copolymer (=60 / 30 / 10 [mass ratio]), was obtained. The composition of the obtained pigment-dispersed resin 1 is: 1 Confirmed by 1H-NMR, the weight-average molecular weight (Mw) calculated in polystyrene equivalent by GPC was 44600. Furthermore, the acid value was determined to be 65.2 mgKOH / g according to the method described in the JIS standard (JIS K0070:1992).

[0169] -Preparation of Pigment Dispersion C- 4 parts of CI Pigment Blue 15:3 (manufactured by Dainichi Seika Kogyo Co., Ltd.) as a cyan pigment, 2 parts of the pigment dispersion resin 1 obtained as described above, 42 parts of methyl ethyl ketone, 5.5 parts of 1N NaOH aqueous solution, and 87.2 parts of water were mixed and dispersed using 0.1 mmφ zirconia beads in a bead mill at 2500 rpm (revolutions per minute; the same applies hereafter) for 6 hours. The obtained dispersion was concentrated under reduced pressure at 55°C until the methyl ethyl ketone was sufficiently removed by distillation, and some of the water was further removed. The dispersion was then centrifuged at 8000 rpm for 30 minutes using a high-speed centrifugal condenser 7550 (manufactured by Kubota Seisakusho Co., Ltd.) (using a 50 mL centrifuge tube) to remove the precipitate and collect the supernatant. Based on the above, a pigment dispersion C containing a resin-coated pigment in which at least a portion of the cyan pigment is coated by the pigment dispersion resin 1 was obtained.

[0170] -Preparation of an aqueous dispersion of resin particles 1 (Tg 100℃)- 560.0 g of methyl ethyl ketone was placed in a 2-liter three-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube, and the temperature was raised to 87°C. Then, while maintaining reflux in the reaction vessel (reflux was maintained until the end of the reaction), 336.4 g of methyl methacrylate and 6 g of isobornyl methacrylate were added to the methyl ethyl ketone in the reaction vessel. A mixed solution consisting of 9.6 g, 116.0 g of 2-ethylhexyl methacrylate, 58 g of methacrylic acid, 108 g of methyl ethyl ketone, and 2.32 g of "V-601" (a polymerization initiator manufactured by Fujifilm Wako Pure Chemical Industries; dimethyl 2,2'-azobis(2-methylpropionate)) was added dropwise at a constant rate so that the addition was completed in 2 hours. After the addition was completed, the mixture was stirred for 1 hour, and then the following procedure (1) was performed on the solution after stirring for 1 hour. Step (1) ... A solution consisting of 1.16 g of "V-601" and 6.4 g of methyl ethyl ketone was added and stirred for 2 hours.

[0171] Next, the above procedure (1) was repeated four times, and then a solution consisting of 1.16 g of "V-601" and 6.4 g of methyl ethyl ketone was added and stirring was continued for 3 hours (the operations up to this point are referred to as the "reaction"). After the reaction was complete, the solution was cooled to 65°C, and 163.0 g of isopropanol was added and allowed to cool, yielding a polymerization solution (solid content concentration 41.0%) containing a copolymer of methyl methacrylate / isobornyl methacrylate / 2-ethylhexyl methacrylate / methacrylic acid (=58 / 12 / 20 / 10 [mass ratio]). The copolymer described above had a weight-average molecular weight (Mw) of 35,000 and an acid value of 65.1 (mgKOH / g).

[0172] Next, 317.3 g of the obtained polymerization solution (solid content concentration 41.0% by mass) was weighed, and 46.4 g of isopropanol, 1.65 g of 20% maleic anhydride aqueous solution (water-soluble acidic compound, equivalent to 0.3% by mass of maleic acid relative to the copolymer), and 40.77 g of 2 mol / L NaOH aqueous solution were added thereto, and the temperature of the liquid in the reaction vessel was raised to 70°C. Next, 380 g of water was added dropwise to the solution, which had been heated to 70°C, at a rate of 10 mL / min to perform aqueous dispersion (dispersion step). Subsequently, 287.0 g of isopropanol, methyl ethyl ketone, and water were removed by distillation under reduced pressure by maintaining the temperature of the liquid in the reaction vessel at 70°C for 1.5 hours (solvent removal step). To the obtained liquid, 0.278 g of Proxel GXL(S) (manufactured by Arch Chemicals Japan Co., Ltd.) (440 ppm as benzoisothiazolin-3-one relative to the polymer solids) was added. The obtained liquid was filtered through a 1 μm filter, and the filtrate was collected to obtain an aqueous dispersion of resin particles 1 with a solid content concentration of 26.5% by mass. The Tg of resin particle 1 was 100°C, and the volume-average particle size was 10 nm.

[0173] -Preparation of Ink A- Ink A having the following composition was prepared using pigment dispersion C, aqueous dispersion of resin particles 1, 1,2-propanediol (hereinafter also referred to as "PG"; a water-soluble organic solvent with a boiling point of less than 220°C), surfactant (Orphine® E1010 manufactured by Nisshin Chemical Industry Co., Ltd.), colloidal silica (Snowtex® XS (20% by mass solids) manufactured by Nissan Chemical Corporation), and water.

[0174] -Composition of Ink A- • Cyan pigment… 4% by mass • Pigment dispersion resin 1… 2% by mass • 1,2-Propanediol (PG; water-soluble organic solvent with a boiling point below 220°C) ... 25% by mass • Surfactant (Orphine® E1010, manufactured by Nisshin Chemical Industry Co., Ltd.) ... 0.5% by mass ·Resin particles 1...5% by mass • Colloidal silica (Snowtex® XS manufactured by Nissan Chemical Corporation (20% silica solids by mass))... 0.06% by mass as silica solids • Water… Remaining amount that is 100% by mass overall

[0175] (Preparation of inks B to H) Inks B through H were prepared as the first inks in the same manner as ink A, except that the ink composition was changed as shown in Table 1. In Table 1, HDO is 1,2-hexanediol, which is a high-boiling point solvent (i.e., an organic solvent with a boiling point of 220°C or higher). Resin particle 2 is a resin particle synthesized as follows: Resin particle 3 is a resin particle synthesized as follows.

[0176] -Preparation of an aqueous dispersion of resin particles 2 (Tg 80℃)- An aqueous dispersion of resin particles 2 with a solid content of 26.5% by mass was obtained in the same manner as the aqueous dispersion of resin particles 1, except that the amount of each monomer added was changed so that the copolymerization ratio in the copolymer [methyl methacrylate / isobornyl methacrylate / 2-ethylhexyl methacrylate / methacrylic acid] was 42 / 11 / 37 / 10 [mass ratio], the weight-average molecular weight (Mw) was 35000, and the acid value was 65.1 (mgKOH / g). The Tg of resin particle 2 was 80°C, and the volume-average particle size was 10 nm.

[0177] -Preparation of an aqueous dispersion of resin particles 3 (Tg 120℃)- An aqueous dispersion of resin particles 3 with a solid content of 26.5% by mass was obtained in the same manner as the aqueous dispersion of resin particles 1, except that the amount of each monomer added was changed so that the copolymerization ratio in the copolymer [methyl methacrylate / isobornyl methacrylate / 2-ethylhexyl methacrylate / methacrylic acid] was 70 / 16 / 4 / 10 [mass ratio], the weight-average molecular weight (Mw) was 35000, and the acid value was 65.1 (mgKOH / g). The Tg of the resin particles 3 is 120°C, and the volume average particle diameter was 10 nm.

[0178] (Preparation of Ink I) An ink as the second ink was prepared as follows.

[0179] - Synthesis of Pigment Dispersion Resin 2 - Pigment dispersion resin 2 was synthesized as described below. Dipropylene glycol in an amount equal to the total mass of the monomers described below was added to a three-necked flask equipped with a stirrer and a cooling tube, and the mixture was heated to 85°C under a nitrogen atmosphere. Solution 1 was prepared by mixing 9.1 molar equivalents of stearyl methacrylate, 34.0 molar equivalents of benzyl methacrylate, 31.9 molar equivalents of hydroxyethyl methacrylate, 25.0 molar equivalents of methacrylic acid, and 0.8 molar equivalents of 2-mercaptopropionic acid. Solution 2 was prepared by dissolving 1% by mass, relative to the total mass of the monomers, of t-butyl peroxy-2-ethylhexanoate (Perbutyl O manufactured by NOF Corporation) in 20% by mass, relative to the total mass of the monomers, of dipropylene glycol. Solution 1 and Solution 2 were respectively added dropwise into the three-necked flask over 4 hours and 5 hours, respectively. After completion of the dropwise addition, the reaction was allowed to proceed for additional 2 hours, then the temperature was raised to 95°C, and the mixture was heated and stirred for 3 hours to react all unreacted monomers. Disappearance of the monomers was confirmed by nuclear magnetic resonance( 1 H-NMR) method. The obtained reaction solution was heated to 70°C, 20.0 molar equivalents of dimethylethanolamine as an amine compound was added, then propylene glycol was added and the mixture was stirred, thereby obtaining a 30% by mass solution of pigment dispersion resin 2. The constituent components of the obtained polymer were 1 confirmed by 1H-NMR. Further, the weight average molecular weight (Mw) determined by GPC was 22,000. Note that the mass ratio of each constituent unit in the pigment dispersion resin 2 is derived from stearyl methacrylate The ratio of constituent units from benzyl methacrylate, hydroxyethyl methacrylate, and methacrylic acid was 20 / 39 / 27 / 14. However, the above mass ratio does not include dimethylaminoethanol.

[0180] -Preparation of pigment dispersion W- Using a Ladymill Model LSG-4U-08 (manufactured by AIMEX), pigment dispersion W was prepared as follows. In a zirconia container, 45 parts by mass of titanium dioxide particles (TiO2 particles; average primary particle diameter: 210 nm, trade name: PF-690, manufactured by Ishihara Sangyo Co., Ltd.) as a white pigment (white inorganic pigment), 15 parts by mass of a 30% by mass solution of the above pigment dispersion resin 2, and 40 parts by mass of ultrapure water were added. Furthermore, 40 parts by mass of 0.5 mmφ zirconia beads (manufactured by TORAY, Treceram beads) were added and lightly mixed with a spatula. The zirconia container containing the obtained mixture was placed in a ball mill and dispersed at a rotation speed of 1000 rpm for 5 hours. After dispersion was complete, the beads were removed by filtering with a filter cloth to obtain a pigment dispersion W with a TiO2 concentration of 45% by mass.

[0181] -Preparation of Ink I- Ink I was prepared using a pigment dispersion W, an aqueous dispersion of resin particles 3, 1,2-propanediol (PG; a water-soluble organic solvent with a boiling point of less than 220°C), a surfactant (Orphine® E1010 manufactured by Nisshin Chemical Industry Co., Ltd.), colloidal silica (Snowtex® XS (20% solids by mass) manufactured by Nissan Chemical Corporation), and water, having the following composition.

[0182] -Composition of Ink I- ·White pigment (TiO2)…8% by mass • Pigment dispersion resin 2… 0.5% by mass • 1,2-Propanediol (PG; water-soluble organic solvent with a boiling point below 220°C) ... 25% by mass • Surfactant (Orphine® E1010, manufactured by Nisshin Chemical Industry Co., Ltd.) ... 1.2% by mass ·Resin particles 3...6% by mass • Colloidal silica (Snowtex® XS manufactured by Nissan Chemical Corporation (20% silica solids by mass))... 0.06% by mass as silica solids • Water… Remaining amount that is 100% by mass overall

[0183] (Preparation of inks J-M) Inks J through M were prepared as second inks in the same manner as ink I, except that the ink composition was changed as shown in Table 1.

[0184] [Table 1]

[0185] [Examples 1-21, Comparative Examples 1-8] The pretreatment solution, the first ink, and the second ink were used in the combinations shown in Table 2, and the following measurements, image recordings, and evaluations were performed.

[0186] <Measurements of each ink> For the first inks (inks A to H), the surface tension and mixture viscosity A1 were measured using the method described above. Furthermore, the Tg (°C) of the first resin in the first inks (inks A to H) was determined. For the second inks (inks I-M), the surface tension and mixture viscosity A2 were measured using the method described above. Furthermore, the Tg (°C) of the second resin in the second inks (inks I-M) was determined. Based on the results obtained, the surface tension difference (i.e., the value obtained by subtracting the surface tension of the second ink from the surface tension of the first ink), the viscosity difference of the mixture (A1-A2) (mPa·s), and the Tg difference (Ta-Tb) (°C) were determined for each example. The results are shown in Table 2.

[0187] <Manufacturing of image recordings> A polyethylene terephthalate (PET) substrate (FE2001, manufactured by Futamura Chemical Co., Ltd., 12 μm thick, 540 mm wide, and 4000 m long) was prepared as the non-permeable substrate on which the image was recorded (hereinafter also simply referred to as "substrate").

[0188] A transport mechanism for transporting the substrate, Arranged in this order from the upstream side in the substrate transport direction, the system includes a wire bar coater for applying pretreatment liquid, a first inkjet head for applying the first ink, and a second inkjet head for applying the second ink. An image recording device equipped with the following features was prepared. Both the first and second inkjet heads were 1200 dpi / 20-inch wide piezo full-line heads. Here, dpi stands for dots per inch. The arrangement of both the first and second inkjet heads was such that the nozzle arrangement direction was inclined at 75.7° with respect to the direction perpendicular to the substrate transport direction (i.e., the width direction of the substrate). The ink ejection surface of each of the above inkjet heads (i.e., the first inkjet head and the second inkjet head) is provided with a liquid-repellent film containing a fluorine compound. The liquid-repellent film containing the fluorine compound is C8F 17 It is a monolayer (SAM film) of C2H4SiCl3.

[0189] The substrate, pretreatment liquid, first ink, and second ink were set in the image recording device described above. The pretreatment liquid, first ink, and second ink were applied to the substrate under conditions where overlapping areas were created in a planar view, where the areas to which the pretreatment liquid was applied, the areas to which the first ink was applied, and the areas to which the second ink was applied overlapped (i.e., application arrangement), and an image was recorded. This resulted in obtaining an image recording. Details are provided below.

[0190] The substrate was moved at a constant speed of 500 mm / second while the pretreatment solution was applied to the substrate using a wire bar coater. The amount of pretreatment solution applied is shown in the "Amount of Pretreatment Solution Applied" column in Table 2 (unit: g / m²). 2 The amount of coagulant added to the pretreatment solution was as shown in the "Amount of coagulant added" column in Table 2 (unit: g / m³). 2 )

[0191] "Amount of pretreatment solution applied" (unit: g / m²) 2 This value is obtained by dividing the mass of the applied pretreatment solution by the area of ​​the region to which the pretreatment solution was applied. "Amount of flocculant applied" (unit: g / m 2 ) is the "amount of pretreatment solution applied" (unit: g / m 2 This value is determined based on the following: the amount of coagulant relative to the total volume of the pretreatment solution (mass %).

[0192] At the point where the pretreatment solution had been applied, drying of the pretreatment solution was started using a dryer at 50°C 1.5 seconds after the completion of the pretreatment solution application, and drying was completed 3.5 seconds after the completion of the pretreatment solution application. The drying time at this point was 2 seconds.

[0193] After the pretreatment solution had dried, the substrate was moved at a constant stage speed of 50 mm / second, and the first ink was ejected from the first inkjet head onto the dried pretreatment solution to form a solid image. Then, the second ink was ejected from the second inkjet head onto the applied first ink to form a solid image. In this process, the second ink was applied to the entire surface of the first ink applied to the substrate. That is, the overlapping regions in this embodiment and comparative example group coincide with the regions where the first ink is applied and the regions where the second ink is applied, respectively. Next, the first and second inks were dried at 70°C for 10 seconds. As a result, a solid image having a laminated structure in which a solid white film made of a second ink film is laminated on a solid cyan film made of a first ink film was obtained. That is, an image recording material comprising a substrate and the solid image provided on the substrate was obtained.

[0194] Here, the ejection conditions for both the first and second inks were set to an ejection frequency of 24 kHz and a resolution of 1200 dpi × 1200 dpi (dots per inch). The droplet volume of the first ink and the second ink, respectively, when ejecting them was adjusted according to the respective amounts of the first ink and the second ink applied. For example, in Example 1, the droplet volume of the first ink was 3.0 pL (the amount of the first ink applied was 7.0 g / m²). 2 (Compatible with) and the droplet volume of the second ink is set to 3.3 pL (second ink application amount 7.8 g / m²) 2 (This corresponds to) Both the first and second inks were degassed through a degassing filter and heated to 30°C.

[0195] The amounts of the first ink and the second ink are as shown in the "First Ink Amount" and "Second Ink Amount" columns in Table 2, respectively (all units are g / m²). 2 The amounts of the first resin and the second resin were as shown in the "Amount of First Resin" and "Amount of Second Resin" columns in Table 2, respectively (all in units of g / m²). 2 )

[0196] "First ink application amount" (unit: g / m²) 2 This value is obtained by dividing the mass of the first ink applied to the overlapping region by the area of ​​the overlapping region. "First resin application amount" (unit: g / m 2 ) is the "first ink application amount" (unit: g / m²). 2 This value is determined based on the content (mass%) of the first resin relative to the total amount of the first ink. "Second ink application amount" (unit: g / m²) 2 This value is obtained by dividing the mass of the second ink applied to the overlapping region by the area of ​​the overlapping region. "Second resin application amount" (unit: g / m 2 ) is the "second ink application amount" (unit: g / m²). 2 This value is calculated based on the content (mass%) of the second resin relative to the total amount of the second ink.

[0197] Based on the amount of flocculant applied, the amount of the first resin applied, and the amount of the second resin applied, the application mass ratio [(first resin + second resin) / flocculant] (i.e., the ratio of the total application mass of the first and second resins per unit area to the application mass of flocculant per unit area) was determined. The obtained mass ratio [(1st resin + 2nd resin) / coagulant] is shown in the "Amount ratio [resin / coagulant]" column of Table 2.

[0198] <Rating> The following evaluation was performed on the above image recordings.

[0199] (Lamination strength (L strength)) From the image recording obtained above, a 500mm long x 500mm wide area (hereinafter also referred to as the laminate strength evaluation area) with a solid image covering the entire surface was cut out and used as the laminate strength evaluation sample. On a solid image of the laminate strength evaluation sample, a dry laminating adhesive (main component TM-320 (isocyanate compound) / curing agent CAT-13B (alcohol compound), manufactured by Toyo Morton Co., Ltd.) was applied using a bar coater and dried at 70°C for 10 seconds. Then, an unoriented polypropylene film (CPP) film (product name: Pyrene P1128, manufactured by Toyobo Co., Ltd., thickness 25 μm) was laid on top as the laminating substrate. In this state, the laminating substrate and the laminate strength evaluation sample were bonded together to obtain a laminate.

[0200] The resulting laminate was aged at 40°C for 48 hours. A sample piece measuring 100mm in length and 15mm in width was cut from the aged laminated material. Next, the laminating substrate and the laminate strength evaluation sample were manually separated in a region of 30 mm in length from one end of the longitudinal direction of the sample piece. The remaining 70 mm region was left with the laminating substrate and the laminate strength evaluation sample bonded together. Next, a tensile test was performed on the delaminated portion of the sample piece, pulling the laminate substrate and the delaminated portion of the laminate strength evaluation sample in opposite directions. The pulling direction was perpendicular to the remaining 70 mm length region (the region where the laminate substrate and the laminate strength evaluation sample remained bonded together). This tensile test determined the peel strength required to separate the laminating substrate from the laminate strength evaluation sample in the remaining 70 mm length region, and the obtained peel strength was defined as the laminate strength. Based on the obtained laminate strength, the laminate strength between the laminate strength evaluation sample (i.e., the image recording) and the laminating substrate was evaluated according to the following evaluation criteria. This allowed us to evaluate the laminate strength between the image in the image recording and the laminating substrate (hereinafter also referred to as "L strength"). The results are shown in Table 2. The above tensile tests were performed using a tensile testing machine (TENSILON RTM-25, manufactured by Orientec Co., Ltd.).

[0201] -Evaluation criteria for laminate strength (L strength)- 5. The lamination strength between the image recording and the laminating substrate is 2N / 15mm or higher. 4. The lamination strength between the image recording and the laminating substrate is 1.5 N / 15 mm or more and less than 2 N / 15 mm. 3: The lamination strength between the image recording material and the laminating substrate is 1 N / 15 mm or more and less than 1.5 N / 15 mm. 2: The lamination strength between the image recording and the laminating substrate is 0.5 N / 15 mm or more and less than 1 N / 15 mm. 1: The lamination strength between the image recording and the laminating substrate is less than 0.5 N / 15 mm.

[0202] <Evaluation of adhesion> The adhesion of the image was evaluated by attaching a piece of cellophane tape (registered trademark, No. 405, manufactured by Nichiban Co., Ltd., 12 mm wide, hereinafter also simply referred to as "tape") to the solid image of the image recording obtained above, and then peeling off the tape piece. The tape was applied and removed using the following method. The tape was removed at a constant speed, cut to a length of approximately 75 mm, and obtained tape pieces. The obtained tape piece was placed over the solid image, and a 12mm wide and 25mm long area in the center of the tape piece was stuck to it with a finger and rubbed firmly with the fingertip. Within 5 minutes of applying the tape piece, grasp the end of the tape piece and peel it off in 0.5 to 1.0 seconds at an angle as close to 60° as possible. The presence or absence of adhering material on the detached tape piece and the presence or absence of peeling of the solid image on the recording medium were visually observed, and the adhesion of the image was evaluated according to the evaluation criteria below. The results are shown in Table 2. In the evaluation criteria below, rank "5" represents the best level of adhesion.

[0203] -Evaluation Criteria for Adhesion- 5: No residue was found on the tape fragment, and no peeling of the image on the recording medium was observed. 4: Some colored residue was observed on the tape fragments, but no peeling of the image on the recording medium was observed. 3: Some colored residue is observed on the tape fragments, and some peeling is observed on the image on the recording medium, but these are within a practically acceptable range. 2: Colored material was observed on the tape fragments, and peeling was also observed on the image on the recording medium, exceeding the limits of what is practically acceptable. 1: A colored substance is observed on the tape fragment, the image on the recording medium is almost completely peeled off, and the recording medium is visible.

[0204] [Table 2]

[0205] -Explanation of Table 2- The units for the amount of pretreatment solution applied, the amount of flocculant applied, the amount of the first ink applied, the amount of the first resin applied, and the amount of the second ink applied are all g / m². 2 That is the case. The amount (%) of high-boiling-point solvent in the first ink refers to the content (mass%) of high-boiling-point solvent (specifically, 1,2-hexanediol (HDO)) relative to the total amount of the first ink, and the amount (%) of high-boiling-point solvent (specifically, 1,2-hexanediol (HDO)) in the second ink refers to the content (mass%) of high-boiling-point solvent relative to the total amount of the second ink. The surface tension difference refers to the value obtained by subtracting the surface tension of the second ink from the surface tension of the first ink. • The ratio of resin / coagulant to be applied is equal to the mass ratio of (first resin + second resin) / coagulant (i.e.) This refers to the ratio of the total mass of the first and second resins applied per unit area to the mass of the flocculant applied per unit area. Ta-Tb is the value obtained by subtracting Tb from Ta, where Ta is the glass transition temperature of the resin particles in the first resin and the resin particles in the second resin that have a larger mass imparted per unit area in the overlapping region, and Tb is the glass transition temperature of the resin particles that have a smaller mass imparted per unit area. A1-A2 is the difference between A1 and A2, where A1 is the viscosity of the mixture obtained by mixing the pretreatment solution and the first ink, and A2 is the viscosity of the mixture obtained by mixing the pretreatment solution and the second ink. The method for measuring A1-A2 is as described above.

[0206] As shown in Table 2, the image recordings obtained in Examples 1 to 21 by applying the pretreatment solution, the first ink, and the second ink under conditions where the surface tension difference (i.e., the value obtained by subtracting the surface tension of the second ink from the surface tension of the first ink) was greater than 0 mN / m, and the application ratio [resin / coagulant] was between 16.0 and 30.0, showed excellent lamination strength (L strength) and image adhesion. In contrast, the image recordings of Comparative Examples 1, 6, and 7, manufactured under conditions where the application ratio [resin / aggregant] was less than 16.0, showed excellent image adhesion, but reduced laminate strength. This is thought to be because excessive aggregation of the resin caused irregularities and / or variations in thickness on the image surface. Furthermore, the image recordings of Comparative Examples 2, 5, and 8, which were manufactured under conditions where the application ratio [resin / aggregant] exceeded 30.0, showed reduced adhesion and laminate strength. This is thought to be because insufficient resin aggregation reduced the adhesion of the image, which is the basis for laminate strength. Furthermore, the image recordings of Comparative Examples 3 and 4, manufactured using the first and second inks with a surface tension difference of 0 mN / m or less, exhibited excellent image adhesion, but reduced lamination strength. This is thought to be due to insufficient spreading of the second ink, resulting in unevenness and / or variations in thickness on the image surface.

[0207] Of Examples 1, 2, 6, and 7, Examples 1 and 2, in which the application ratio [resin / flocculant] was 16.0 or more and 25.0 or less, showed superior lamination strength and image adhesion.

[0208] Of Examples 1, 13, and 14, Example 1, in which the first ink did not contain a high-boiling point solvent (i.e., an organic solvent with a boiling point (bp) of 220°C or higher), and Example 13, in which the first ink contained a high-boiling point solvent but the content of the high-boiling point solvent was 5% by mass or less, exhibited superior lamination strength and adhesion. Of Examples 1, 15, and 16, Example 1, in which the second ink did not contain a high-boiling point solvent (i.e., an organic solvent with a boiling point of 220°C or higher), and Example 15, in which the second ink contained a high-boiling point solvent but the content of the high-boiling point solvent was 5% by mass or less, exhibited superior lamination strength and adhesion.

[0209] Comparing Examples 1 and 20, Example 1, in which the pretreatment solution contained resin and the Tg of the resin contained in the pretreatment solution was lower than the Tg of the resin particles in the first resin, showed superior lamination strength and adhesion compared to Example 20, in which the pretreatment solution did not contain resin. Comparing Examples 5 and 21, Example 5, in which the pretreatment solution contained resin and the Tg of the resin contained in the pretreatment solution was lower than the Tg of the resin particles in the first resin, showed superior lamination strength and adhesion.

[0210] Of Examples 1 and 18, Example 1, which satisfies the relationship 0°C ≤ Ta-Tb ≤ 30°C, exhibited superior lamination strength and adhesion.

[0211] Of Examples 1 and 19, Example 1, which satisfies A1-A2>0mPa·s, is a laminate. It was superior in terms of strength.

[0212] The above describes a group of examples in which cyan ink was used as the first ink and white ink as the second ink, but this disclosure is not limited to the embodiments of these examples. For example, it goes without saying that the same effects as those described above can be obtained when the first ink is changed to an ink other than cyan ink (e.g., magenta ink, yellow ink, black ink, etc.) in the above-described group of embodiments, when a multi-color image is recorded using cyan ink plus at least one other ink as the first ink, and when at least one other ink than white ink is used as the second ink.

Claims

1. A step of preparing a pretreatment solution containing a flocculant, which is at least one selected from the group consisting of organic acids, organic acid salts, polyvalent metal compounds, and metal complexes, and water. A step of preparing a first ink containing a first pigment, a first resin, water, and a surfactant 1, wherein the amount of the surfactant 1 is 0.01% to 0.8% by mass relative to the total amount of the first ink, A step of preparing a second ink containing a second pigment, a second resin, water, and a surfactant 2, wherein the amount of the surfactant 2 is 0.8% to 5% by mass relative to the total amount of the second ink, An image recording step in which the pretreatment liquid, the first ink, and the second ink are applied in this order to a non-permeable substrate to record an image, Includes, A method for manufacturing an image recording material, wherein the image recording step is performed under conditions that an overlapping region is created in a plan view where the region to which the pretreatment liquid is applied, the region to which the first ink is applied, and the region to which the second ink is applied overlap, and in the overlapping region, the ratio of the total mass of the first resin and the second resin applied per unit area to the mass of the flocculant applied per unit area is 16.0 or more and 30.0 or less.

2. The method for manufacturing an image recording according to claim 1, wherein the ratio is 16.0 or more and 25.0 or less.

3. The first ink contains 5% by mass or less of an organic solvent with a boiling point of 220°C or higher relative to the total amount of the first ink. The method for manufacturing an image recording material according to claim 1 or claim 2, wherein the second ink contains 5% by mass or less of an organic solvent with a boiling point of 220°C or higher relative to the total amount of the second ink.

4. The aforementioned pretreatment liquid contains a resin, The first resin contains resin particles, A method for producing an image recording material according to any one of claims 1 to 3, wherein the glass transition temperature of the resin contained in the pretreatment liquid is lower than the glass transition temperature of the resin particles contained in the first resin.

5. The first resin contains resin particles, The second resin contains resin particles, A method for manufacturing an image recording material according to any one of claims 1 to 4, wherein, among the resin particles contained in the first resin and the resin particles contained in the second resin, in the overlapping region, the glass transition temperature of the one with a larger impartment per unit area is denoted as Ta, and the glass transition temperature of the one with a smaller impartment per unit area is denoted as Tb, and Ta and Tb satisfy the relationship 0°C ≤ Ta - Tb ≤ 30°C.

6. A method for manufacturing an image recording material according to any one of claims 1 to 3, wherein when the viscosity of a mixture obtained by mixing the pretreatment liquid and the first ink is A1, and the viscosity of a mixture obtained by mixing the pretreatment liquid and the second ink is A2, A1 and A2 satisfy the condition A1 - A2 > 0 mPa·s.

7. A method for producing an image recording material according to any one of claims 1 to 3, wherein the pretreatment liquid contains a resin, and the resin is at least one selected from the group consisting of acrylic resin, polyester resin, polyolefin resin, polyurethane resin, polyurea resin, polyamide resin, polycarbonate resin, and polystyrene resin, and is a water-insoluble resin.

8. A method for manufacturing an image recording according to any one of claims 1 to 7 The process of obtaining, A step of obtaining a laminated body by laminating a laminating substrate onto the side of the image recording material on which the image is recorded, A method for manufacturing a laminate containing [the specified substance].

Images