Inkjet recording method and method for manufacturing laminated body

Abstract

This ink-jet recording method comprises: a step for preparing a white ink that contains water and a white pigment; a step for preparing a coloring ink that contains water and a coloring pigment; a step for obtaining a colored image by applying the coloring ink on a non-permeable substrate by ink-jet method; and a step for obtaining a white image having a surface roughness Ra of 0.10-0.40 μm by applying the white ink on the colored image by ink-jet method. The present invention also pertains to an application of said method.

Description

[Technical Field]

[0001] This disclosure relates to an inkjet recording method and a method for manufacturing a laminated body. [Background technology]

[0002] Conventionally, various studies have been conducted regarding image recording using white ink and colored ink (i.e., non-white ink).

[0003] For example, Japanese Patent Publication No. 2018-94902 discloses an ink set comprising a non-white ink having a non-white colorant and thermoplastic resin particles with a volume average particle size of 30 to 110 nm, and a white ink having a white colorant and thermoplastic resin particles, and also discloses that each of these inks is applied by an inkjet method. [Overview of the project] [Problems that the invention aims to solve]

[0004] Incidentally, there are cases where an image recording material is manufactured in which a colored image and a white image are arranged in that order on a non-permeable substrate by an inkjet recording method, in which a colored ink and a white ink are applied to a non-permeable substrate using an inkjet method. One example of this is to use a transparent substrate as an impermeable substrate, record a pattern image such as a character image as a colored image, and then record a solid white image to cover the entire area where the pattern image is recorded. In this case, the pattern image as a colored image is viewed through the substrate from the side of the substrate where the image is not recorded (i.e., the side opposite to the side where the image is recorded). Furthermore, in some cases, a laminated body is manufactured by laminating a laminating substrate onto the white image in the image recording material of the above embodiment, and in some cases, it is required to improve the lamination strength in this case (i.e., the lamination strength between the white image in the image recording material and the laminating substrate).

[0005] An object of one aspect of this disclosure is to provide an inkjet recording method that can produce an image recording material in which a colored image and a white image are arranged in that order on a non-permeable substrate, and which has excellent lamination strength when a laminating substrate is laminated onto the white image. An object of another aspect of the present disclosure is to provide a method for manufacturing a laminate, which comprises the image recording and a laminating substrate laminated onto the white image of the image recording, and which can produce a laminate with excellent lamination strength between the image recording and the laminating substrate. [Means for solving the problem]

[0006] The following embodiments are included as specific means for solving the above problems. <1> A step of preparing a white ink containing water and white pigment, A step of preparing a colored ink containing water and coloring pigments, A process of obtaining a colored image by applying colored ink to a non-permeable substrate using an inkjet method, A process of applying white ink to a colored image using an inkjet method to obtain a white image with a surface roughness Ra of 0.10 μm to 0.40 μm, An inkjet recording method, including... <2> The surface roughness Ra of the white image is 0.15 μm to 0.30 μm. <1> The inkjet recording method described above. <3> The amount of white pigment in the white image is 0.7 g / m². 2 That's all. <1> or <2> The inkjet recording method described above. <4> The white ink further contains resin particles. <1> ~ <3> The inkjet recording method described in one of the following documents. <5> The process for obtaining a white image is: Applying white ink to a colored image using an inkjet method, The process involves applying white ink to a colored image and then heating and drying it under conditions where the time from application to the start of heat drying is 10 seconds or less to obtain a white image. including The inkjet recording method according to any one of <1> to <4>. <6> The heat drying is carried out under the condition that the residual solvent amount in the white ink applied on the colored image is 0.10 g / m within 70 seconds from the start of the heat drying. 2 The inkjet recording method according to <5>, which is carried out under the following conditions. <7> The step of obtaining a colored image includes applying a colored ink onto a non-permeable substrate by an inkjet method, and heating and drying the colored ink applied on the non-permeable substrate under the condition that the residual solvent amount is 0.10 g / m 2 to obtain a colored image by heating and drying under the following conditions. including The inkjet recording method according to any one of <1> to <6>. <8> Further, a step of preparing a pretreatment liquid containing water and a flocculant, and a step of applying the pretreatment liquid onto a non-permeable substrate, which is provided before the step of obtaining a colored image. including In the step of obtaining a colored image, a colored ink is applied onto the region where the pretreatment liquid is applied on the non-permeable substrate to obtain a colored image. The inkjet recording method according to any one of <1> to <7>. <9> The step of applying the pretreatment liquid includes applying the pretreatment liquid onto a non-permeable substrate, and heating and drying the pretreatment liquid applied on the non-permeable substrate under the condition that the residual moisture amount is 0.03 g / m 2 to heat and dry under the following conditions. including The inkjet recording method according to <8>. <10> A step of obtaining an image recording product in which a colored image and a white image are arranged in this order on a non-permeable substrate by the inkjet recording method according to any one of <1> to <9>, and a step of laminating a laminating substrate onto the white image of the image recording product to obtain a laminate. A method for manufacturing a laminate including

Advantages of the Invention

[0007] According to one aspect of the present disclosure, there is provided an inkjet recording method capable of manufacturing an image recording material in which a colored image and a white image are arranged in this order on a non-permeable substrate, and the image recording material has excellent laminating strength when a laminating substrate is laminated on the white image. According to another aspect of the present disclosure, there is provided a manufacturing method of a laminate body including the image recording material and a laminate substrate laminated on the white image of the image recording material, and the laminate body has excellent laminating strength between the white image in the image recording material and the laminate substrate.

Embodiments for Carrying Out the Invention

[0008] In this specification, the numerical range indicated by using "~" means a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

[0009] In this specification, the amount of each component in the composition means the total amount of a plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved.

[0010] In this specification, "image" means the entire film formed by ink, and "image recording" means the formation of an image (i.e., a film). Furthermore, the concept of "image" as used herein also includes solid images.

[0011] In this specification, "colored ink" means ink of a color other than white, and "colored pigment" means pigment of a color other than white. The concept of colored ink includes black ink, and the concept of colored pigment also includes black pigment.

[0012] In this specification, "(meth)acrylate" is a concept that encompasses both acrylate and methacrylate. "(Meth)acrylic" is a concept that encompasses both acrylic and methacrylic. The term "alkylene glycol" is a concept that encompasses both monoalkylene glycols and polyalkylene glycols. "Alkylene glycol alkyl ether" is a concept that encompasses monoalkylene glycol monoalkyl ethers, monoalkylene glycol polyalkyl ethers, polyalkylene glycol monoalkyl ethers, and polyalkylene glycol polyalkyl ethers.

[0013] [Inkjet recording method] The inkjet recording method disclosed herein (hereinafter also simply referred to as the "recording method") A step of preparing a white ink containing water and white pigment, A step of preparing a colored ink containing water and coloring pigments, A process of obtaining a colored image by applying colored ink to a non-permeable substrate using an inkjet method, A process of applying white ink to a colored image using an inkjet method to obtain a white image with a surface roughness Ra of 0.10 μm to 0.40 μm, Includes. The recording method described herein may include other steps as necessary.

[0014] According to the recording method of this disclosure, an image recording material can be manufactured in which a colored image and a white image are arranged in that order on a non-permeable substrate, and which has excellent lamination strength (i.e., lamination strength between the white image and the lamination substrate in the image recording material) when a laminating substrate is laminated onto the white image. The reason for this effect is presumed to be as follows: In the recording method of this disclosure, since the surface roughness Ra of the white image on the colored image is 0.10 μm or more, it is thought that the contact area between the white image and the laminate substrate can be increased when a laminate substrate is further laminated onto the white image. As a result, it is thought that the lamination strength of the image recording material (i.e., the lamination strength between the white image and the laminate substrate in the image recording material) will be improved. Furthermore, by having a surface roughness Ra of 0.40 μm or less for the white image recorded on the colored image, the conformability of the laminate substrate to the surface of the white image is improved when laminating the laminate substrate onto the white image (i.e., the formation of gaps between the surface of the white image and the laminate substrate is suppressed), and as a result, the lamination strength of the image recording is expected to improve.

[0015] In this disclosure, the surface roughness Ra of the white image on the colored image means the arithmetic mean roughness Ra of the surface of the white image on the colored image as defined in JIS B0601:2001. The surface roughness Ra of the white image on this colored image is measured, for example, using a color 3D laser microscope "VK-9710" manufactured by KEYENCE.

[0016] In the recording method of this disclosure, the white image is recorded such that the surface roughness Ra of the white image recorded on the colored image is 0.10 μm to 0.40 μm. The method for adjusting the surface roughness Ra of the white image to within the range of 0.10 μm to 0.40 μm can be appropriately selected. for example, By appropriately selecting combinations of the composition of the colored ink (e.g., particle size of colored pigment, amount of colored pigment, presence or absence of resin particles, etc.), the conditions for forming the colored image (e.g., combination of colored ink application conditions and drying conditions), the composition of the white ink (e.g., particle size of white pigment, amount of white pigment, presence or absence of resin particles, etc.), and the conditions for forming the white image (e.g., combination of white ink application conditions and drying conditions), the surface roughness Ra of the white image formed on the colored image can be adjusted to a range of 0.10 μm to 0.40 μm.

[0017] The following describes each step included in the recording method of this disclosure.

[0018] <Preparing white ink> The recording method of this disclosure includes the step of preparing a white ink containing water and a white pigment. The following describes the white ink to be prepared in this process.

[0019] (water) White 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 white ink. The upper limit of the water content depends on the amounts of other components, but is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, relative to the total amount of white ink.

[0020] (White pigment) White ink contains white pigment. The white pigment can be any pigment that exhibits a white color, and its type is not particularly limited. Examples of white pigments include inorganic pigments (i.e., particles) such as titanium dioxide, strontium titanate, barium titanate, zinc oxide, magnesium oxide, zirconium oxide, aluminum oxide, barium sulfate, silica, talc, mica, aluminum hydroxide, calcium silicate, aluminum silicate, and zinc sulfide. The white pigment is preferably made up of titanium atoms, and more preferably titanium oxide particles.

[0021] The average particle size of the white pigment is preferably 200 nm or larger, more preferably 250 nm or larger, and even more preferably 280 nm or larger. The larger the average particle size of the white pigment, the easier it is to adjust the surface roughness Ra of the resulting white image to a range of 0.10 μm or greater.

[0022] The average particle size of the white pigment is preferably 550 nm or less, more preferably 450 nm or less, and even more preferably 400 nm or less. The smaller the average particle size of the white pigment, the easier it is to adjust the surface roughness Ra of the resulting white image to a range of 0.0.40 μm or less.

[0023] In this disclosure, the particle size distribution of the pigment may be either a broad particle size distribution or a monodisperse particle size distribution. The average particle size and particle size distribution of the pigment are determined by measuring the volume-average particle size using dynamic light scattering with a particle size distribution analyzer, such as the "NanoTrack UPA-EX150" manufactured by Nikkiso Co., Ltd. When a pigment is coated with a pigment dispersant, the average particle size of the pigment refers to the average particle size of the pigment coated with the pigment dispersant.

[0024] The white pigment content is preferably 10% by mass or more, and more preferably 14% by mass or more, relative to the total amount of white ink. The higher the white pigment content relative to the total amount of white ink, the easier it is to adjust the surface roughness Ra of the resulting white image to a range of 0.10 μm or higher. The content of the white pigment is preferably 25% by mass or less, and more preferably 20% by mass or less, relative to the total amount of white ink. The lower the amount of white pigment relative to the total amount of white ink, the easier it is to adjust the surface roughness Ra of the resulting white image to a range of 0.40 μm or less.

[0025] (Organic solvents) White ink is preferably made to contain an organic solvent from the viewpoint of its ejection properties from the inkjet head (hereinafter also simply referred to as "ejection properties").

[0026] From the viewpoint of further improving the ejection performance, it is more preferable for the white ink to contain a first organic solvent, which is an organic solvent with a boiling point of 120°C or higher.

[0027] In this disclosure, “boiling point” means the boiling point at 1 atmosphere (101325 Pa). The boiling point is measured using a boiling point meter, for example, using a boiling point measuring instrument (product name “DosaTherm300”, manufactured by Titan Technologies).

[0028] Examples of organic solvents with a boiling point of 120°C or higher as the first organic solvent include: Alcohols such as 1,3-butanediol (207°C), 1,4-butanediol (228°C), benzyl alcohol (205°C), and terpionelle (217°C); Alkylene glycols such as ethylene glycol (197°C), diethylene glycol (244°C), triethylene glycol (287°C), propylene glycol (187°C), and dipropylene glycol (230°C); Diethylene glycol monomethyl ether (194°C), diethylene glycol monoethyl ether (202°C), diethylene glycol monobutyl ether (231°C), diethylene glycol dimethyl ether (162°C), diethylene glycol ethyl methyl ether (176°C), diethylene glycol isopropyl methyl ether (179°C), triethylene glycol monomethyl ether (249°C), triethylene glycol dimethyl ether (216°C), propylene glycol monomethyl ether (121°C), propylene glycol monobutyl ether (170°C), propylene glycol monopropyl ether (150°C), 3-methyl ether Alkylene glycol alkyl ethers such as toxy-3-methyl-1-butanol (174°C), diethylene glycol monohexyl ether (above 261°C), propylene glycol monomethyl ether propionate (160°C), methyl cellosolve (ethylene glycol monomethyl ether, 125°C), ethyl cellosolve (ethylene glycol monoethyl ether, 135°C), butyl cellosolve (ethylene glycol monobutyl ether, 171°C), ethylene glycol mono-tert-butyl ether (153°C), tripropylene glycol monomethyl ether (243°C), and dipropylene glycol monomethyl ether (188°C); Esters such as ethylene glycol monomethyl ether acetate (145°C), diethylene glycol monoethyl ether acetate (217°C), ethyl acetate (154°C), ethyl lactate (154°C), and 3-methoxybutyl acetate (172°C); Ketones such as diacetone alcohol (169°C), cyclohexanone (156°C), and cyclopentanone (131°C); These are some examples. In the examples above, the numbers in parentheses indicate the boiling point.

[0029] If the white ink contains a first organic solvent, the white ink may further contain an organic solvent with a boiling point of less than 120°C. The proportion of the first organic solvent in the organic solvent contained in the white ink is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The above proportion may be 100% by mass. That is, all of the organic solvent contained in the white ink may be the first organic solvent.

[0030] If the white ink contains a first organic solvent, the content of the first organic solvent is preferably 30% by mass or less, more preferably 28% by mass or less, and even more preferably 26% by mass or less, based on the total amount of the white ink.

[0031] If the white ink contains a first organic solvent, the lower limit of the content of the first organic solvent is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the total amount of the white ink.

[0032] From the viewpoint of further improving the lamination strength of the image recording material, it is preferable that the white ink contains an organic solvent with a boiling point of 120°C to 200°C (hereinafter also referred to as "first organic solvent A"). The proportion of first organic solvent A in the organic solvent contained in the white ink is preferably 50% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. The above proportion may be 100% by mass. In other words, all of the organic solvent contained in the white ink may be first organic solvent A.

[0033] The first organic solvent A preferably contains at least one selected from the group consisting of alkylene glycols and alkylene glycol alkyl ethers.

[0034] (Pigment dispersant) White ink may contain a pigment dispersant. In this disclosure, a pigment dispersant has the function of dispersing pigments. When a white ink contains a pigment dispersant, the pigment dispersant can be adsorbed onto the surface of the white pigment, coating at least a portion of its surface, thereby allowing the white pigment to be dispersed in water. Furthermore, if a self-dispersing pigment that can disperse in water even without a pigment dispersant is used as the white pigment, the white ink does not need to contain a pigment dispersant.

[0035] The form of the pigment dispersant contained in the white ink is not particularly limited and may be a random polymer, a block polymer, or a graft polymer. Furthermore, the pigment dispersant contained in the white ink may be a polymer having a cross-linked structure. In particular, the pigment dispersant contained in the white ink is preferably a polymer or block polymer having a cross-linked structure. When the pigment dispersant is a polymer or block polymer having a cross-linked structure, it is thought that the pigment dispersant is less likely to detach from the surface of the white pigment, resulting in high dispersion stability of the white pigment. As a result, when the white ink reacts with the pretreatment solution, the white pigment aggregates uniformly, resulting in a uniform image, easier evaporation of the organic solvent, and improved laminate strength. Furthermore, even when a pretreatment solution is not used, after the white ink lands on a non-permeable substrate, the solvent ratio in the white ink increases as water evaporates, making the dispersion of the white pigment more unstable. In this case, if the pigment dispersant is a polymer or block polymer having a cross-linked structure, uneven aggregation of the white pigment is suppressed, resulting in a uniform image, easier evaporation of the organic solvent, and improved laminate strength.

[0036] In this disclosure, "polymer" refers to a compound with a weight-average molecular weight of 1000 or more.

[0037] In this disclosure, weight-average molecular weight refers to the value measured by gel permeation chromatography (GPC). The GPC measurement is performed using an HLC®-8020GPC (manufactured by Tosoh Corporation) as the measuring instrument, with three TSKgel® Super Multipore HZ-H columns (4.6 mm ID × 15 cm, manufactured by Tosoh Corporation), and THF (tetrahydrofuran) as the eluent. The measurement is performed with 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. A calibration curve is prepared from eight samples of 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".

[0038] - A polymer with a cross-linked structure - A polymer having a cross-linked structure is not particularly limited as long as it has at least one cross-linked structure within its molecule.

[0039] Whether or not the polymers contained in the ink have a cross-linked structure can be determined, for example, by the following method. First, the polymers are separated from the ink using a separation method such as solvent extraction. The separated polymers can then be analyzed using various analytical methods such as nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and thermal analysis to comprehensively determine whether or not they have a cross-linked structure.

[0040] A polymer having a crosslinked structure (hereinafter also referred to as "crosslinked polymer") is formed, for example, by crosslinking an uncrosslinked polymer (hereinafter also referred to as "uncrosslinked polymer") with a crosslinking agent. The uncrosslinked polymer is preferably a water-soluble polymer.

[0041] In this disclosure, "water-soluble" means the property of dissolving 1 g or more in 100 g of water at 25°C. Preferably, "water-soluble" means dissolving 3 g or more (more preferably 10 g or more) in 100 g of water at 25°C.

[0042] Furthermore, even if an uncrosslinked polymer is water-soluble, the crosslinked polymer is not necessarily water-soluble.

[0043] Examples of uncrosslinked polymers include vinyl resins, acrylic resins, urethane resins, and polyester resins. Among these, acrylic resin is preferred as the uncrosslinked polymer.

[0044] The uncrosslinked polymer is preferably a polymer having functional groups that can be crosslinked by a crosslinking agent. Examples of crosslinkable functional groups include carboxyl groups or their salts, isocyanate groups, and epoxy groups. Among these, from the viewpoint of improving the dispersibility of the pigment, the crosslinkable functional group is preferably a carboxyl group or its salt, and a carboxyl group is particularly preferred. In other words, the uncrosslinked polymer is preferably a polymer containing carboxyl groups.

[0045] The uncrosslinked polymer is preferably a copolymer containing structural units derived from monomers containing carboxyl groups (hereinafter referred to as "carboxyl group-containing monomers"). The copolymer may contain only one type of structural unit derived from carboxyl group-containing monomers, or two or more types. The copolymer may be a random copolymer or a block copolymer, but it is preferably a random copolymer.

[0046] Examples of monomers containing a carboxyl group include (meth)acrylic acid, β-carboxyethyl acrylate, fumaric acid, itaconic acid, maleic acid, and crotonic acid.

[0047] The carboxyl group-containing monomer is preferably (meth)acrylic acid or β-carboxyethyl acrylate, with (meth)acrylic acid being more preferred, from the viewpoint of crosslinkability and dispersibility.

[0048] The content of structural units derived from carboxyl group-containing monomers is preferably 5% to 40% by mass, more preferably 10% to 35% by mass, and even more preferably 10% to 30% by mass, based on the total amount of the uncrosslinked polymer.

[0049] The uncrosslinked polymer preferably contains structural units derived from hydrophobic monomers in addition to structural units derived from carboxyl group-containing monomers. The copolymer may contain only one type of structural unit derived from hydrophobic monomers, or two or more types.

[0050] Examples of hydrophobic monomers include (meth)acrylates having alkyl groups with 1 to 20 carbon atoms, (meth)acrylates having aromatic rings (e.g., benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, etc.), styrene, and styrene derivatives.

[0051] The content of structural units derived from hydrophobic monomers is preferably 60% to 95% by mass, more preferably 65% ​​to 90% by mass, and even more preferably 70% to 90% by mass, relative to the total amount of the uncrosslinked polymer.

[0052] The uncrosslinked polymer is preferably a random copolymer comprising structural units derived from a carboxyl group-containing monomer and at least one of structural units derived from (meth)acrylate having an alkyl group with 1 to 20 carbon atoms and structural units derived from (meth)acrylate having an aromatic ring; more preferably a random copolymer comprising structural units derived from (meth)acrylic acid and structural units derived from (meth)acrylate having an aromatic ring; and even more preferably a copolymer comprising structural units derived from (meth)acrylic acid and structural units derived from benzyl (meth)acrylate.

[0053] The weight-average molecular weight (Mw) of the uncrosslinked polymer is not particularly limited, but from the viewpoint of the dispersibility of the white pigment, it is preferably 3,000 to 300,000, more preferably 5,000 to 200,000, and even more preferably 7,000 to 100,000.

[0054] The preferred range for the weight-average molecular weight of the crosslinked polymer is the same as the preferred range for the weight-average molecular weight of the uncrosslinked polymer.

[0055] In this disclosure, the weight-average molecular weight (Mw) is measured by gel permeation chromatography (GPC). The GPC is performed using an HLC-8220GPC (manufactured by Tosoh Corporation), with three columns connected in series: TSKgeL SuperHZM-H, TSKgeL SuperHZ4000, and TSKgel SuperHZ2000 (all product names of Tosoh Corporation). THF (tetrahydrofuran) is used as the eluent. The conditions are 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, and the measurement is performed using a differential refractive index detector. Furthermore, the calibration curve will be created 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".

[0056] The crosslinking agent used when crosslinking an uncrosslinked polymer is preferably a compound having two or more reaction sites with the uncrosslinked polymer (for example, a polymer having a carboxyl group). One type of crosslinking agent may be used, or two or more types may be used.

[0057] A preferred combination of a crosslinking agent and an uncrosslinked polymer is a compound having two or more epoxy groups (i.e., a bifunctional or more epoxy compound) and a polymer having a carboxyl group. In this combination, a crosslinked structure is formed by the reaction between the epoxy groups and the carboxyl groups. It is preferable that the formation of the crosslinked structure by the crosslinking agent is carried out after the pigment has been dispersed by the uncrosslinked polymer.

[0058] Examples of bifunctional or more epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether.

[0059] Among these, the preferred epoxy compounds with two or more functions are polyethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, or trimethylolpropane triglycidyl ether.

[0060] The crosslinking agent can be a commercially available product. Examples of commercially available products include Denacol EX-321, EX-821, EX-830, EX-850, and EX-851 (manufactured by Nagase ChemteX).

[0061] The molar ratio of the reaction sites in the crosslinking agent (e.g., epoxy groups) to the reaction sites in the uncrosslinked polymer (e.g., carboxyl groups) is preferably 1:1.1 to 1:10, more preferably 1:1.1 to 1:5, and even more preferably 1:1.1 to 1:3, from the viewpoint of crosslinking reaction rate and dispersion stability after crosslinking.

[0062] -Block Polymer- A block polymer, also known as a block copolymer, is a copolymer in which at least two polymers are bonded together within the molecule.

[0063] The block polymer preferably contains structural units derived from hydrophobic monomers and structural units derived from monomers containing anionic groups (hereinafter referred to as "anionic group-containing monomers").

[0064] The structural units derived from hydrophobic monomers contained in the block polymer may be one type or two or more types. The structural units derived from anionic group-containing monomers contained in the block polymer may be one type or two or more types.

[0065] Structural units derived from hydrophobic monomers include ethylenically unsaturated compounds having an aromatic ring structure or an alicyclic structure, and (meth)acrylates having an alkyl group with 1 to 20 carbon atoms.

[0066] The content of structural units derived from hydrophobic monomers is preferably 35% to 95% by mass, more preferably 50% to 95% by mass, and even more preferably 70% to 90% by mass, relative to the total amount of the block polymer.

[0067] From the viewpoint of adsorption with pigments, the hydrophobic monomer preferably contains an ethylenically unsaturated compound having an aromatic ring structure or an alicyclic structure, more preferably contains an ethylenically unsaturated compound having an alicyclic structure, and even more preferably contains an ethylenically unsaturated compound having an alicyclic structure with 6 or more carbon atoms.

[0068] The content of structural units derived from ethylenically unsaturated compounds having an aromatic ring structure or an alicyclic structure is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, even more preferably 30% to 70% by mass, and still more preferably 30% to 60% by mass, based on the total amount of the block polymer.

[0069] The structural units derived from hydrophobic monomers may also preferably include (meth)acrylates having an alkyl group with 1 to 20 carbon atoms. The alkyl group may be linear or branched.

[0070] Examples of (meth)acrylates having an alkyl group with 1 to 20 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate.

[0071] The content of structural units derived from (meth)acrylates having an alkyl group with 1 to 20 carbon atoms is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, even more preferably 30% to 70% by mass, and particularly preferably 40% to 60% by mass, based on the total amount of the block polymer.

[0072] In structural units derived from anionic group-containing monomers, examples of anionic groups include carboxyl groups, salts of carboxyl groups, sulfo groups, salts of sulfo groups, phosphate groups, salts of phosphate groups, phosphonic acid groups, and salts of phosphonic acid groups.

[0073] Counterions in salts include alkali metal ions such as sodium ions, potassium ions, and lithium ions; alkaline earth metal ions such as calcium ions and magnesium ions; and ammonium ions.

[0074] In particular, the anionic group is preferably a carboxyl group or a salt of a carboxyl group. Examples of anionic group-containing monomers include (meth)acrylic acid, β-carboxyethyl acrylate, fumaric acid, itaconic acid, maleic acid, and crotonic acid. In particular, the anionic group-containing monomer is preferably (meth)acrylic acid.

[0075] The content of structural units derived from anionic group-containing monomers is preferably 1% to 30% by mass, more preferably 2% to 25% by mass, and even more preferably 3% to 20% by mass, based on the total amount of the block polymer.

[0076] Whether or not the polymer contained in the ink is a block polymer can be determined, for example, by the following method. First, the polymer is separated from the ink using a separation method such as solvent extraction. The separated polymer is then analyzed using various analytical methods such as nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and thermal analysis, and its physical properties, such as the glass transition temperature, are measured to comprehensively determine whether or not it is a block polymer.

[0077] The weight-average molecular weight (Mw) of the block polymer is not particularly limited, but from the viewpoint of pigment dispersibility, it is preferably 3,000 to 100,000, more preferably 5,000 to 80,000, and even more preferably 10,000 to 60,000.

[0078] The mixing ratio of the white pigment to the pigment dispersant is preferably 1:0.02 to 1:2 by mass, more preferably 1:0.03 to 1:1.5, and even more preferably 1:0.04 to 1:1.

[0079] Known dispersion devices can be used to disperse pigments, including, for example, ball mills, sand mills, bead mills, roll mills, jet mills, paint shakers, attritors, ultrasonic dispersers, and dispersers.

[0080] (Resin particles) From the viewpoint of improving the lamination strength of the image recording, the white ink preferably contains resin particles. In other words, it is preferable that the white ink contains resin particles, which are particles made of resin, in addition to the pigment dispersant.

[0081] When white ink contains resin particles, it is easier to adjust the surface roughness Ra of the resulting white image to a range of 0.10 μm or greater. This is thought to be because the viscosity of the ink increases significantly when it dries when white ink contains resin particles.

[0082] Furthermore, if the recording method of this disclosure includes a step of applying a pretreatment solution as described later, when white ink is applied to an area of ​​a non-permeable substrate to which the pretreatment solution has been applied, the flocculant contained in the pretreatment solution comes into contact with the resin particles contained in the white ink, destabilizing the dispersion of the resin particles and thereby increasing the viscosity of the white ink. As a result, the adhesion of the white ink to the non-permeable substrate is further improved, and consequently, the lamination strength of the image recording is further improved.

[0083] The resin constituting the resin particles is preferably a water-insoluble polymer. In the context of water-insoluble polymers, "water-insoluble" means that the amount that dissolves in 100g of distilled water at 25°C is less than 2g.

[0084] The resin particles preferably contain at least one of particles made of acrylic resin (hereinafter referred to as "acrylic resin particles") and particles made of urethane resin (hereinafter also referred to as "urethane resin particles"), and it is preferable that they contain acrylic resin particles.

[0085] The resin particles are preferably self-dispersible resin particles. Examples of self-dispersible resin particles include those described in paragraphs 0062 to 0076 of Japanese Patent Publication No. 2016-188345 and paragraphs 0109 to 0140 of International Publication No. 2013 / 180074.

[0086] The resin in the resin particles is preferably an acrylic resin containing structural units derived from (meth)acrylate having an aromatic ring structure or an alicyclic structure, structural units derived from (meth)acrylic acid, and structural units derived from alkyl (meth)acrylate containing an alkyl group having 1 to 4 carbon atoms.

[0087] The (meth)acrylate having an alicyclic structure is preferably an alkyl (meth)acrylate having a cycloalkyl group with 3 to 10 carbon atoms, and preferably at least one selected from the group consisting of cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, and dicyclopentanyl (meth)acrylate, and more preferably at least one selected from the group consisting of isobornyl (meth)acrylate, adamantyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. The (meth)acrylate having an aromatic ring structure is preferably phenoxyethyl (meth)acrylate or benzyl (meth)acrylate.

[0088] Examples of resins used in resin particles include phenoxyethyl acrylate / methyl methacrylate / acrylic acid copolymer (50 / 45 / 5), phenoxyethyl acrylate / benzyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (30 / 35 / 29 / 6), phenoxyethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (50 / 44 / 6), phenoxyethyl acrylate / methyl methacrylate / ethyl acrylate / acrylic acid copolymer (30 / 55 / 10 / 5), and benzyl methacrylate. Benzyl acrylate / isobutyl methacrylate / methacrylic acid copolymer (35 / 59 / 6), styrene / phenoxyethyl acrylate / methyl methacrylate / acrylic acid copolymer (10 / 50 / 35 / 5), benzyl acrylate / methyl methacrylate / acrylic acid copolymer (55 / 40 / 5), phenoxyethyl methacrylate / benzyl acrylate / methacrylic acid copolymer (45 / 47 / 8), styrene / phenoxyethyl acrylate / butyl methacrylate / acrylic acid copolymer (5 / 48 / 40 / 7), benzyl methacrylate / isobutyl methacrylate Tyl methacrylate / cyclohexyl methacrylate / methacrylic acid copolymer (35 / 30 / 30 / 5), phenoxyethyl acrylate / methyl methacrylate / butyl acrylate / methacrylic acid copolymer (12 / 50 / 30 / 8), benzyl acrylate / isobutyl methacrylate / acrylic acid copolymer (93 / 2 / 5), methyl methacrylate / methoxyethyl acrylate / benzyl methacrylate / acrylic acid copolymer (44 / 15 / 35 / 6), styrene / butyl acrylate / acrylic acid copolymer (62 / 35 / 3), methyl Methyl methacrylate / phenoxyethyl acrylate / acrylic acid copolymer (45 / 51 / 4), methyl methacrylate / isobornyl methacrylate / methacrylic acid copolymer (20 / 72 / 8), methyl methacrylate / isobornyl methacrylate / methacrylic acid copolymer (40 / 52 / 8), methyl methacrylate / isobornyl methacrylate / methacrylic acid copolymer (48 / 42 / 10), methyl methacrylate / isobornyl methacrylate / dicyclopentanyl methacrylate / methacrylic acid copolymer (20 / 62 / 10 / 8),Examples include methyl methacrylate / dicyclopentanyl methacrylate / methacrylic acid copolymer (20 / 72 / 8) and methyl methacrylate / isobornyl methacrylate / methacrylic acid copolymer (70 / 20 / 10). The values ​​in parentheses represent the mass ratio of structural units derived from monomers. Furthermore, the (meth)acrylic acid constituting the resin may be partially or entirely a salt.

[0089] 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.

[0090] The weight-average 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.

[0091] From the viewpoint of discharge stability, the 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.

[0092] Here, the average particle size of the resin particles is determined by measuring the volume-average particle size using dynamic light scattering with a particle size distribution analyzer, for example, the "NanoTrack UPA-EX150" product manufactured by Nikkiso Co., Ltd.

[0093] If the white ink contains resin particles, the resin particle content is preferably 0.1% to 15% by mass, more preferably 0.5% to 10% by mass, and even more preferably 2% to 10% by mass, relative to the total amount of white ink.

[0094] (Other ingredients) White ink may contain other components as needed. Other components include, for example, surfactants, co-sensitizers, UV absorbers, antioxidants, colorfastness inhibitors, conductive salts, and basic compounds.

[0095] (Physical properties) The pH of the white ink is preferably 7 to 10, and more preferably 7.5 to 9.5, from the viewpoint of improving ejection stability. The pH is measured at 25°C using a pH meter, for example, using a pH meter (model number "HM-31") manufactured by Toa DKK.

[0096] The viscosity of the white ink is preferably 0.5 mPa·s to 30 mPa·s, more preferably 2 mPa·s to 20 mPa·s, preferably 2 mPa·s to 15 mPa·s, and even more preferably 3 mPa·s to 10 mPa·s. The viscosity is measured at 25°C using a viscometer, for example, using a TV-22 viscometer manufactured by Toki Sangyo Co., Ltd.

[0097] The surface tension of the white ink 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. The surface tension is measured at 25°C using a surface tensimeter, for example, by the plate method using an automatic surface tensimeter (product name "CBVP-Z") manufactured by Kyowa Interface Science Co., Ltd.

[0098] <Preparing colored ink> The recording method of this disclosure includes the step of preparing a colored ink containing water and a coloring pigment. The colored ink prepared in this process may be one type or two or more types. It is preferable to prepare two or more colored inks in this process in order to record a multi-color image. The following describes the colored inks to be prepared in this process.

[0099] (water) The colored 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 colored ink. The upper limit of the water content depends on the amounts of other components, but is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, relative to the total amount of colored ink.

[0100] (Coloring pigments) Colored inks contain coloring pigments. The coloring pigment may be a chromatic pigment, a black pigment, or a combination of one or more chromatic pigments and one or more black pigments.

[0101] The chromatic pigment can be any pigment that exhibits a chromatic color, and its type is not particularly limited.

[0102] The chromatic pigments are not particularly limited and include, for example, cyan pigment, magenta pigment, yellow pigment, blue pigment, red pigment, green pigment, orange pigment, and violet pigment.

[0103] Examples of chromatic pigments include organic pigments such as azo pigments, disazo pigments, condensed disazo pigments, phthalocyanine pigments, quinacridone pigments, quinacridone quinone pigments, anthraquinone pigments, aminoanthraquinone pigments, anthanthrone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perinone pigments, perylene pigments, isoindoline pigments, isoindolinone pigments, isobiolanthrone pigments, benzimidazolon pigments, indanthron pigments, triarylcarbonium pigments, and diketopyrrolopyrrole pigments.

[0104] For more details, see the following as examples of chromatic pigments: Perylene pigments such as CI Pigment Red 190, CI Pigment Red 224, and CI Pigment Violet 29; Perinone pigments such as CI Pigment Orange 43 and CI Pigment Red 194; quinacridone pigments such as CI Pigment Violet 19, CI Pigment Violet 42, CI Pigment Red 122, CI Pigment Red 192, CI Pigment Red 202, CI Pigment Red 207, and Pigment Red 209; Quinacridone quinone pigments such as CI Pigment Red 206, CI Pigment Orange 48, and CI Pigment Orange 49; Anthraquinone pigments such as CI Pigment Yellow 147; Anthanthrone pigments such as CI Pigment Red 168; Benzimidazolone pigments such as CI Pigment Brown 25, CI Pigment Violet 32, CI Pigment Orange 36, CI Pigment Yellow 120, CI Pigment Yellow 180, Pigment Yellow 181, CI Pigment Orange 62, CI Pigment Red 185, etc. Condensed disazo pigments such as CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 95, CI Pigment Yellow 128, CI Pigment Yellow 166, CI Pigment Orange 34, CI Pigment Orange 13, CI Pigment Orange 31, Pigment Red 144, Pigment Red 166, Pigment Red 220, CI Pigment Red 221, CI Pigment Red 242, Pigment Red 248, CI Pigment Red 262, CI Pigment Brown 23, etc. Disazo pigments such as CI Pigment Yellow 13, CI Pigment Yellow 83, and CI Pigment Yellow 188; Azo pigments such as CI Pigment Red 187, CI Pigment Red 170, CI Pigment Yellow 74, CI Pigment Yellow 150, CI Pigment Red 48, Pigment Red 53, CI Pigment Orange 64, CI Pigment Red 247, etc. Indanthron pigments such as CI Pigment Blue 60; Phthalocyanine pigments such as CI Pigment Green 7, CI Pigment Green 36, CI Pigment Green 37, CI Pigment Green 58, CI Pigment Blue 16, CI Pigment Blue 75, and Pigment Blue 15; Triarylcarbonium pigments such as CI Pigment Blue 56 and CI Pigment Blue 61; Dioxazine pigments such as CI Pigment Violet 23 and CI Pigment Violet 37; Aminoanthraquinone pigments such as CI Pigment Red 177; Diketopyrrolopyrrole pigments such as CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 264, CI Pigment Red 272, CI Pigment Orange 71, CI Pigment Orange 73, etc. Thioindigo pigments such as CI Pigment Red 88; Isoindoline pigments such as CI Pigment Yellow 139 and Pigment Orange 66; isoindolinone pigments such as Pigment Yellow 109 and CI Pigment Orange 61; Pyrantron pigments such as CI Pigment Orange 40 and CI Pigment Red 216; and Examples include isobiolantron pigments such as CI Pigment Violet 31.

[0105] The black pigment can be any pigment that exhibits black color, and its type is not particularly limited. Examples of black pigments include carbon black and titanium black.

[0106] The average particle size of the coloring pigment is preferably 10 nm to 200 nm, more preferably 10 nm to 150 nm, and even more preferably 10 nm to 110 nm. The method for measuring the average particle size of colored pigments is the same as the method for measuring the average particle size of white pigments described above.

[0107] From the viewpoint of image density and ejection performance, the content of the coloring pigment is preferably 1% to 15% by mass, and more preferably 2% to 10% by mass, relative to the total amount of colored ink.

[0108] (Organic solvents) From the viewpoint of ejection properties, it is preferable that the colored ink contains an organic solvent. The preferred embodiments of the organic solvent that may be contained in the colored ink (i.e., preferred type, preferred content, etc.) are the same as the preferred embodiments of the organic solvent that may be contained in the white ink.

[0109] (Pigment dispersant) The colored ink may contain a pigment dispersant. A preferred embodiment of the pigment dispersant that can be contained in a colored ink is the same as a preferred embodiment of the pigment dispersant that can be contained in a white ink.

[0110] (Resin particles) The colored ink may contain resin particles. The preferred embodiment of resin particles that can be contained in colored ink is the same as the preferred embodiment of resin particles that can be contained in white ink.

[0111] (Other ingredients) The colored ink may contain other components as needed. Preferred embodiments of other components that may be contained in the colored ink are the same as preferred embodiments of other components that may be contained in the white ink.

[0112] (Physical properties) The preferred embodiments of the physical properties of the colored ink (i.e., pH, viscosity, and surface tension) are the same as the preferred embodiments of the physical properties of the white ink.

[0113] <Process for obtaining a colored image> The recording method of this disclosure includes the step of applying a colored ink to a non-permeable substrate by an inkjet method to obtain a colored image.

[0114] (Non-permeable base material) In this disclosure, non-permeable substrates are defined as having a 24-hour water absorption rate of 2.5% or less, as measured in accordance with ASTM D570-98 (2018). Here, the unit of water absorption rate, "%", is based on mass. The above water absorption rate is preferably 1.0% or less, and more preferably 0.5% or less.

[0115] The non-permeable substrate may be a non-permeable substrate that is transparent. Here, "transparent" means that the transmittance of visible light with wavelengths of 400 nm to 700 nm is 80% or more (preferably 90% or more). If the non-permeable substrate is a transparent non-permeable substrate, the colored image can be easily viewed through the non-image recording side of the non-permeable substrate.

[0116] Examples of materials for non-permeable substrates include glass, metals (e.g., aluminum, zinc, copper, etc.), and resins (e.g., polyvinyl chloride, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, nylon, acrylic resin, etc.).

[0117] The material of the non-permeable substrate is preferably a resin. In particular, from the standpoint of versatility, the material of the non-permeable substrate is preferably polypropylene, polyethylene, polyethylene terephthalate, nylon, acrylic resin, or polyvinyl chloride.

[0118] The shape of the non-permeable substrate is preferably in the form of a sheet (film) or a plate. Examples of non-permeable substrates having such shapes include glass plates, metal plates, resin sheets (resin films), paper laminated with plastic, paper laminated or vapor-deposited with metal, and plastic sheets (plastic films) laminated or vapor-deposited with metal.

[0119] Examples of non-permeable resin substrates include resin sheets (resin films), specifically, flexible packaging materials for packaging food products, and panels for floor guidance in mass retail stores.

[0120] In addition to sheet-like (film-like) or plate-like non-permeable substrates, examples of non-permeable substrates include textiles and nonwoven fabrics formed from non-permeable fibers.

[0121] The thickness of the non-permeable substrate is preferably 0.1 μm to 1,000 μm, more preferably 0.1 μm to 800 μm, and even more preferably 1 μm to 500 μm.

[0122] Non-permeable substrates may be subjected to hydrophilic treatment. Hydrophilization treatments include, but are not limited to, corona treatment, plasma treatment, flame treatment, heat treatment, abrasion treatment, light irradiation treatment (e.g., UV treatment), and fire treatment. Corona treatment can be performed, for example, using a Corona Master (product name "PS-10S", manufactured by Shinko Electric Instruments Co., Ltd.). The conditions for corona treatment should be appropriately selected depending on the type of non-permeable substrate, etc.

[0123] The recording method of this disclosure may include a preheating step of preheating a non-permeable substrate to which a colored ink is applied before the step of obtaining a colored image. The heating temperature in the preheating process can be set appropriately depending on the type of non-permeable substrate, but it is preferable to set the temperature of the non-permeable substrate to 30°C to 70°C, and more preferably to 30°C to 60°C.

[0124] (Method of applying colored ink) In the process of obtaining a colored image, a colored ink is applied to a non-permeable substrate using an inkjet method to obtain a colored image.

[0125] The resulting colored image is an image that is covered by a white image, which will be described later. Considering this point, it is preferable that the colored image be a pattern image such as characters or shapes.

[0126] The application of colored ink by the inkjet method is performed by ejecting the colored ink from the nozzles of the inkjet head.

[0127] There are no particular restrictions on the method of ejecting the colored ink; any known method may be used, for example, 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, irradiates the ink with it, and ejects 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.

[0128] As an inkjet method, the method described in Japanese Patent Publication No. 54-59936 is particularly effective, as it involves the ink undergoing a rapid volume change due to the action of thermal energy, and the force resulting from this state change ejects the ink from the nozzle. As an inkjet method, the method described in paragraphs 0093 to 0105 of Japanese Patent Publication No. 2003-306623 can also be applied.

[0129] 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.

[0130] 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.

[0131] The application of colored ink is preferably carried out using an inkjet head having a resolution of 300 dpi or higher (more preferably 600 dpi or higher, and even more preferably 800 dpi or higher). Here, dpi is an abbreviation for dots per inch, and 1 inch is equal to 2.54 cm.

[0132] From the viewpoint of obtaining high-definition images, the amount of colored ink droplets ejected from the nozzles of the inkjet head is preferably 1 pL (picoliters) to 10 pL, and more preferably 1.5 pL to 6 pL. Furthermore, from the viewpoint of improving the uniformity of the colored image and the continuity of continuous gradations, it is also effective to eject different appropriate amounts of ink in combination.

[0133] (heat drying) The process for obtaining a colored image is: Applying colored ink to a non-permeable substrate using an inkjet method, This may also include obtaining the colored image by heating and drying a colored ink applied to a non-permeable substrate.

[0134] There are no particular restrictions on the method of heating and drying, but examples include infrared (IR) drying, hot air drying, and heating and drying using heating devices (e.g., heaters, hot plates, heating furnaces, etc.). The heat drying method may also be a combination of two or more of these methods. Heat drying can be performed by heating the colored ink from at least one of the image recording side and the non-image recording side of a non-permeable substrate.

[0135] Heat drying results in a residual solvent content of 0.10 g / m² in the applied colored ink. 2 It is preferable to carry out the procedure under the following conditions. In this case, the surface roughness Ra of the white image recorded on the colored image can be easily adjusted within the range of 0.10 μm to 0.40 μm. Heat drying is performed so that the amount of residual solvent in the colored ink is 0.10 g / m² within 70 seconds of the start of heat drying. 2 It is more preferable to carry it out under the following conditions.

[0136] In this disclosure, the amount of residual solvent in the ink applied to the non-permeable substrate is determined by gas chromatography.

[0137] The drying temperature (i.e., the temperature of the colored ink) during the heat drying of the colored ink is preferably 35°C or higher, more preferably 40°C or higher, even more preferably 50°C or higher, and even more preferably 60°C or higher. There is no particular upper limit to the heating temperature, but 100°C is preferred, and 90°C is more preferred.

[0138] The drying time for heat drying of the colored ink is not particularly limited, but is preferably 1 to 180 seconds, more preferably 1 to 120 seconds, and even more preferably 1 to 60 seconds.

[0139] When heat drying is performed in the process of obtaining a colored image, it is preferable to perform the heat drying under conditions such that the time from the completion of application of the colored ink to the start of heat drying of the colored ink on a non-permeable substrate is 10 seconds or less. The time from the completion of applying the colored ink to the start of heating and drying the colored ink is preferably 10 seconds or less, and more preferably 5 seconds or less.

[0140] <Process for obtaining a white image> The recording method of this disclosure includes the step of applying white ink to a colored image by an inkjet method to obtain a white image having a surface roughness Ra of 0.10 μm to 0.40 μm.

[0141] The white image obtained in this process is an image that covers the colored image. The white image may be formed across the colored image and the non-formation area of the colored image on the non-permeable substrate. As an example of the recording method of the present disclosure, a substrate having transparency is used as the non-permeable substrate, and a pattern image such as a character image or a graphic image is recorded as the colored image, and a white image as a solid image is recorded so as to cover the entire area where this pattern image is recorded (that is, the entire area on the pattern image and the non-formation area of the image). In this case, the pattern image as the colored image is visually recognized through the substrate from the non-recording surface side of the substrate.

[0142] In this process, the surface roughness Ra of the white image on the colored image (that is, the arithmetic mean roughness Ra of the surface of the white image on the colored image) is 0.10 μm to 0.40 μm. Thereby, as described above, the laminating strength when laminating the laminating substrate on the white image is improved. From the viewpoint of further improving the laminating strength, the surface roughness Ra of the white image on the colored image is preferably 0.15 μm to 0.30 μm.

[0143] In this process, the amount of the white pigment in the obtained white image is 0.7 g / m 2 or more, which is preferable. Thereby, it is easier to adjust the surface roughness Ra of the white image recorded on the colored image within the range of 0.10 μm or more, and it is easier to further improve the laminating strength. The amount of the white pigment in the white image can be adjusted by the application amount of the white ink.

[0144] There is no particular limitation on the upper limit of the amount of the white pigment in the colored image, but examples of the upper limit include, for example, 3.0 g / m 2 , 2.0 g / m 2 , etc.

[0145] There are no particular restrictions on the ejection method for white ink using the inkjet method; for example, the same method as the ejection method for colored ink using the inkjet method, as mentioned above, can be used. The preferred range for resolution and droplet size of the white ink is the same as the preferred range for resolution and droplet size of the colored ink described above.

[0146] (heat drying) The process for obtaining a white image is: Applying white ink to a colored image using an inkjet method, The process involves heating and drying white ink applied to a colored image to obtain a white image, and It may include.

[0147] There are no particular restrictions on the heating and drying method that can be used in the process of obtaining a white image, but for example, the same method as the heating and drying method that can be used in the process of obtaining a colored image can be used.

[0148] Heat drying results in a residual solvent content of 0.20 g / m² in the applied white ink. 2 It is preferable to carry out the procedure under the following conditions. In this case, the surface roughness Ra of the white image recorded on the colored image can be easily adjusted within the range of 0.10 μm to 0.40 μm. From the perspective of obtaining the above effects more effectively, heat drying is performed so that the amount of residual solvent in the applied white ink is 0.15 g / m². 2 The following (more preferably 0.10 g / m²) 2 It is more preferable to carry out the procedure under the following conditions: For heat drying, the residual solvent content in the white ink should be 0.20 g / m² within 70 seconds of the start of heat drying. 2 The following (more preferably 0.15 g / m²) 2 More preferably, 0.10 g / m 2 It is more preferable to carry out the procedure under the following conditions:

[0149] In this disclosure, the amount of residual solvent in the white ink applied to the colored image is the total amount of water and organic solvent (g / m²) in the white ink applied to the colored image.2 ) means. In this disclosure, the amount of organic solvent in the residual solvent in the white ink applied to the colored image is determined by gas chromatography. In this disclosure, the amount of water in the residual solvent in the white ink applied to the colored image is determined by the Karl Fischer method. Specifically, it is determined using a Karl Fischer moisture meter (for example, the CA-310 trace moisture meter manufactured by Nitto Seiko Analytech Co., Ltd.).

[0150] The drying temperature (i.e., the temperature of the white ink) in the heat drying of the white ink is preferably 35°C or higher, more preferably 40°C or higher, even more preferably 50°C or higher, and even more preferably 60°C or higher. There is no particular upper limit to the heating temperature, but 100°C is preferred, and 90°C is more preferred.

[0151] The drying time for the heat drying of the white ink is not particularly limited, but is preferably 1 to 180 seconds, more preferably 1 to 120 seconds, and even more preferably 1 to 60 seconds.

[0152] When heat drying is performed in the process of obtaining a white image, it is preferable to perform the heat drying under conditions where the time from the completion of applying the white ink to the start of heat drying of the white ink is 10 seconds or less. The time from the completion of applying the white ink to the start of heating and drying the white ink is preferably 10 seconds or less, and more preferably 5 seconds or less.

[0153] <Steps to prepare the pretreatment solution, steps to apply the pretreatment solution,> The method of recording information in this disclosure is further described below. A step of preparing a pretreatment solution containing water and a coagulant, This process is provided before the step of obtaining a colored image, and includes a step of applying a pretreatment solution to a non-permeable substrate, It is preferable to include it. In this case, the step of obtaining a colored image is preferably to apply a colored ink to a region on a non-permeable substrate to which a pretreatment solution has been applied.

[0154] In a preferred embodiment using the above-described pretreatment solution, the components of the colored ink and the white ink are aggregated on a non-permeable substrate by the flocculant in the pretreatment solution. In particular, the flocculation effect by the flocculant is high when the colored ink and / or the white ink contain a pigment dispersant and resin particles. As a result, the adhesion between the non-permeable substrate and the colored image is improved, and further, the adhesion between the colored image and the white image is also improved, resulting in the aforementioned lamination strength being further enhanced.

[0155] (water) The pretreatment solution 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, based on 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, more preferably 80% by mass or less, and even more preferably 70% by mass or less, relative to the total amount of the pretreatment solution.

[0156] (Flocculant) The pretreatment solution contains a coagulant. The coagulant is not particularly limited as long as it is a component that coagulates the components in the white ink and the colored ink. The flocculant is preferably at least one selected from the group consisting of polyvalent metal compounds, organic acids, metal complexes, and cationic polymers, and more preferably contains an organic acid.

[0157] -Polyvalent metal compounds- Examples of polyvalent metal compounds include salts of alkaline earth metals in Group 2 of the periodic table (e.g., magnesium, calcium), transition metals in Group 3 of the periodic table (e.g., lanthanum), metals in Group 13 of the periodic table (e.g., aluminum), and lanthanides (e.g., neodymium).

[0158] These metal salts are preferably salts, nitrates, chlorides, or thiocyanates of organic acids, as described later.

[0159] In particular, the polyvalent metal compound is preferably a calcium or magnesium salt of an organic acid (e.g., formic acid, acetic acid, benzoic acid, etc.); a calcium or magnesium salt of nitric acid; calcium chloride, magnesium chloride, or a calcium or magnesium salt of thiocyanate.

[0160] 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.

[0161] -Organic acid- Examples of organic acids include organic compounds that have an acidic group.

[0162] Examples of acidic groups include phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, sulfate groups, sulfonic acid groups, sulfinic acid groups, and carboxyl groups.

[0163] In particular, from the viewpoint of ink aggregation rate, the acidic group is preferably a phosphoric acid group or a carboxyl group, and more preferably a carboxyl group.

[0164] It is preferable that at least a portion of the acidic group is dissociated in the pretreatment solution.

[0165] Examples of organic compounds having a carboxyl group include (meth)acrylic acid, poly(meth)acrylic acid, acetic acid, formic acid, benzoic acid, glycolic acid, malonic acid, malic acid (preferably DL-malic acid), maleic acid, succinic acid, glutaric acid, pimelic acid, adipic acid, fumaric acid, citric acid, tartaric acid, phthalic 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, and nicotinic acid.

[0166] In particular, from the viewpoint of ink aggregation rate, the organic compound having a carboxyl group is preferably a divalent or higher carboxylic acid (hereinafter also referred to as a polyvalent carboxylic acid), and more preferably a dicarboxylic acid.

[0167] Specifically, the polycarboxylic acid is preferably malonic acid, malic acid, maleic acid, succinic acid, glutaric acid, pimelic acid, adipic acid, fumaric acid, tartaric acid, 4-methylphthalic acid, or citric acid, and more preferably malonic acid, malic acid, tartaric acid, succinic acid, glutaric acid, pimelic acid, adipic acid, or citric acid.

[0168] Organic acids with a low pKa (e.g., 1.0 to 5.0) are preferable. This allows for a reduction in the dispersion stability of particles such as pigments and resin particles in ink, which are dispersed and stabilized by weakly acidic functional groups such as carboxyl groups, by bringing them into contact with an organic acid with an even lower pKa.

[0169] The organic acid is preferably low in pKa, highly soluble in water, and has a valency of 2 or higher. Furthermore, it is more preferable that the organic acid has 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.

[0170] -Metal complex- The metal complex preferably contains at least one metal element selected from the group consisting of zirconium, aluminum, and titanium.

[0171] The metal complex is preferably a metal complex that includes 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.

[0172] The metal complex may be a commercially available product. Various organic ligands, especially various polydentate ligands capable of forming metal chelate catalysts, are commercially available. Therefore, the metal complex may be a metal complex prepared by combining a commercially available organic ligand with a metal.

[0173] Examples of metal complexes include zirconium tetraacetylacetonate (e.g., "Orgatics ZC-150" manufactured by Matsumoto Fine Chemicals), zirconium monoacetylacetonate (e.g., "Orgatics ZC-540" manufactured by Matsumoto Fine Chemicals), zirconium bisacetylacetonate (e.g., "Orgatics ZC-550" manufactured by Matsumoto Fine Chemicals), zirconium monoethylacetoacetate (e.g., "Orgatics ZC-560" manufactured by Matsumoto Fine Chemicals), zirconium acetate (e.g., "Orgatics ZC-115" manufactured by Matsumoto Fine Chemicals), and titanium diisopropoxybis(acetylacetonate) (e.g., "Orgatics ZC-150" manufactured by Matsumoto Fine Chemicals). TC-100), Titanium tetraacetylacetonate (e.g., Matsumoto Fine Chemicals' "Orgatics TC-401"), Titanium dioctyloxybis(octylene glycolate) (e.g., Matsumoto Fine Chemicals' "Orgatics TC-200"), Titanium diisopropoxybis(ethylacetoacetate) (e.g., Matsumoto Fine Chemicals' "Orgatics TC-750"), Zirconium tetraacetylacetonate (e.g., Matsumoto Fine Chemicals' "Orgatics ZC-700"), Zirconium triputoxymonoacetylacetonate (e.g., Matsumoto Fine Chemicals' "Orgatics ZC-540"), Zirconium monobutoxyacetylacetonate bis(ethylacetoacetate) (e.g., Matsumoto Fine Chemicals' "Orgatics ZC-570), Zirconium dibutoxy bis(ethyl acetoacetate) (e.g., Matsumoto Fine Chemicals' "Orgatics ZC-580"), Aluminum trisacetylacetonate (e.g., Matsumoto Fine Chemicals' "Orgatics AL-80"), Titanium lactate ammonium salt (e.g., Matsumoto Fine Chemicals' "Orgatics TC-300"), Titanium lactate (e.g., Matsumoto Fine Chemicals' "Orgatics TC-310, 315"), Titanium triethanolamine (Matsumoto Fine Chemicals' "Orgatics")Examples include "TC-400") and zirconyl chloride compounds (for example, "Orgatics ZC-126" manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0174] In particular, the metal complex is preferably a titanium lactate ammonium salt (e.g., "Orgatics TC-300" manufactured by Matsumoto Fine Chemical Co., Ltd.), titanium lactate (e.g., "Orgatics TC-310, 315" manufactured by Matsumoto Fine Chemical Co., Ltd.), titanium triethanolamine (e.g., "Orgatics TC-400" manufactured by Matsumoto Fine Chemical Co., Ltd.), or a zirconyl chloride compound (e.g., "Orgatics ZC-126" manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0175] -Cationic polymer- Furthermore, the pretreatment solution may contain one or more cationic polymers as flocculating components. The cationic polymer is preferably a homopolymer of cationic monomers having primary to tertiary amino groups or quaternary ammonium bases, a copolymer of a cationic monomer and a non-cationic monomer, or a condensed polymer. The cationic polymer may be used in the form of a water-soluble polymer or water-dispersible latex particles. Examples of cationic polymers include polyvinylpyridine salts, polyalkylaminoethyl acrylates, polyalkylaminoethyl methacrylates, polyvinylimidazoles, polyethyleneimines, polybiguanides, polyguanides, polyallylamines, and derivatives thereof.

[0176] From the viewpoint of the viscosity of the pretreatment solution, a smaller weight-average molecular weight of the cationic polymer is preferable. When the pretreatment solution is applied to the recording medium by an inkjet recording method, a weight-average molecular weight of 1,000 to 500,000 is preferable, 1,500 to 200,000 is more preferable, and even more preferable is 2,000 to 100,000. A weight-average molecular weight of 1,000 or more is advantageous in terms of aggregation rate. A weight-average molecular weight of 500,000 or less is advantageous in terms of discharge reliability. However, this does not apply when the pretreatment solution is applied to the recording medium by a method other than an inkjet recording method.

[0177] The pretreatment solution may contain only one type of coagulant, or it may contain two or more types.

[0178] The coagulant content 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, based on the total amount of the pretreatment solution.

[0179] (Organic solvents) The pretreatment solution may contain an organic solvent. Examples of organic solvents that may be included in the pretreatment solution are the same as those that may be included in the white ink. The content of the organic solvent relative to the total amount of the pretreatment solution is preferably 15% by mass or less, and more preferably 10% by mass or less. The content of the organic solvent relative to the total volume of the pretreatment solution may be 0% by mass. In other words, the pretreatment solution does not need to contain an organic solvent.

[0180] (Other ingredients) The pretreatment solution may contain other components as needed. Other components that may be contained in the pretreatment solution include resin particles, surfactants, solid wetting agents, 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 (for example, water-soluble polymer compounds described in paragraphs 0026 to 0080 of Japanese Patent Application Publication No. 2013-001854).

[0181] (Physical properties) The pH of the pretreatment solution is preferably 0.1 to 4.5, and more preferably 0.2 to 4.0, from the viewpoint of the ink aggregation rate. The pH is measured at 25°C using a pH meter, for example, using a pH meter (model number "HM-31") manufactured by Toa DKK.

[0182] The viscosity of the pretreatment solution is preferably 0.5 mPa·s to 10 mPa·s, and more preferably 1 mPa·s to 5 mPa·s, from the viewpoint of the ink coagulation rate. The viscosity is measured using a viscometer at 25°C. The viscosity is measured using a viscometer at 25°C, for example, using a TV-22 viscometer manufactured by Toki Sangyo Co., Ltd.

[0183] 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. The surface tension is measured at a temperature of 25°C. The surface tension is measured at 25°C using a surface tensimeter, for example, by the plate method using an automatic surface tensimeter (product name "CBVP-Z") manufactured by Kyowa Interface Science Co., Ltd.

[0184] (Method of applying pretreatment solution) The method of applying the pretreatment solution is not particularly limited and includes known methods such as coating, immersion, and inkjet recording.

[0185] Known coating methods include those using bar coaters, extrusion die coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, and the like.

[0186] (heat drying) The step of applying the pretreatment solution is: Applying a pretreatment solution to a non-permeable substrate, The pretreatment solution applied to the non-permeable substrate has a remaining moisture content of 0.03 g / m². 2 The following conditions must be met for heating and drying: It is preferable to include it.

[0187] There are no particular restrictions on the method of heat drying that can be performed in the step of applying the pretreatment solution, but for example, a method similar to the heat drying that can be performed in the step of obtaining a colored image can be used.

[0188] Heat drying is performed on a non-permeable substrate using a pretreatment solution, with a remaining moisture content of 0.03 g / m². 2 It is preferable to carry out the procedure under the following conditions. In this case, the surface roughness Ra of the white image recorded on the colored image can be easily adjusted within the range of 0.10 μm to 0.40 μm. From the perspective of obtaining the above effects more effectively, heat drying is performed when the pretreatment solution applied to the non-penetrating substrate has a remaining moisture content of 0.02 g / m². 2 The following (more preferably 0.008 g / m²) 2 It is more preferable to carry out the procedure under the following conditions: Furthermore, during heat drying, the residual moisture content in the pretreatment solution should be 0.03 g / m² within 70 seconds of the start of heat drying. 2 The following (more preferably 0.02 g / m²) 2 More preferably, 0.008 g / m 2 It is even more preferable to carry it out under the following conditions:

[0189] In this disclosure, the residual moisture content in the pretreatment solution is confirmed by the Karl Fischer method. Specifically, it is confirmed using a Karl Fischer moisture meter (for example, the CA-310 trace moisture analyzer manufactured by Nitto Seiko Analytech Co., Ltd.).

[0190] The drying temperature (i.e., the temperature of the pretreatment solution) during the heat drying of the pretreatment solution is preferably 35°C or higher, more preferably 40°C or higher, even more preferably 50°C or higher, and even more preferably 60°C or higher. There is no particular upper limit to the heating temperature, but 100°C is preferred, and 90°C is more preferred.

[0191] The drying time for heating and drying the pretreatment solution is not particularly limited, but is preferably 0.5 to 60 seconds, more preferably 0.5 to 20 seconds, and even more preferably 0.5 to 10 seconds.

[0192] [Method for manufacturing laminated materials] The method for manufacturing the laminated body described herein is: The process of obtaining an image recording in which a colored image and a white image are arranged in that order on a non-permeable substrate using the inkjet recording method of the present disclosure described above, A process of obtaining a laminate by laminating a laminating substrate onto a white image of an image recording, Includes. The method for manufacturing the laminate according to this disclosure may include other steps as necessary.

[0193] The method for manufacturing the laminated body of this disclosure includes the inkjet recording method of this disclosure described above. Therefore, the method for manufacturing a laminate according to the present disclosure provides effects similar to those obtained by the inkjet recording method described above. In other words, according to the method for manufacturing a laminate body of the present disclosure, a laminate body can be manufactured which includes the image recording material and a laminating substrate laminated onto the white image of the image recording material, and which has excellent lamination strength between the white image in the image recording material and the laminating substrate.

[0194] For the process of obtaining an image recording, refer to the inkjet recording method described above.

[0195] The process of obtaining a laminate is to laminate a laminating substrate onto a white image on an image recording to obtain a laminate. In this case, the laminating substrate may be laminated across the white area of ​​the image recording and the area of ​​the image recording where no white area is recorded.

[0196] The laminating substrate is preferably a resin substrate. The resin substrate is not particularly limited, but examples include a substrate made of a thermoplastic resin.

[0197] 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.

[0198] 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.

[0199] In the process of obtaining a laminate, the laminating substrate may be laminated directly onto the white image, or it may be laminated via another layer (e.g., an adhesive layer).

[0200] When laminating a substrate for lamination directly onto a white image, lamination can be carried out by known methods such as heat bonding or heat fusion.

[0201] Furthermore, when laminating a laminating substrate onto a white image via an adhesive layer, the lamination process is, for example; A method of bonding the image recording to the laminated material by applying adhesive to the side on which the image is recorded, placing a laminating substrate on top, and then bonding the image recording to the laminating substrate; Extruded lamination (i.e., sandwich lamination); This can be done by methods such as those listed above.

[0202] The adhesive layer preferably contains an isocyanate compound. When the adhesive layer contains an isocyanate compound, the adhesion between the adhesive layer and the image is further improved, thereby increasing the lamination strength. [Examples]

[0203] The following are examples of the embodiments of this disclosure, but this disclosure is not limited to the following embodiments.

[0204] <Preparation of pretreatment solution> The components shown in Tables 1 to 3 (components other than water in the pretreatment solution (mass %)) were mixed with water to prepare the pretreatment solution.

[0205] The following provides supplementary information regarding Tables 1 to 3. "-" indicates that the product does not contain the corresponding ingredient. Kathiomaster PD-7 is a water-soluble cationic polymer (coagulant) manufactured by Yokkaichi Gosei Co., Ltd. Olphine E1010 and Olphine E1020 are surfactants manufactured by Nisshin Chemical Co., Ltd. Superflex M500 is an aqueous dispersion of urethane resin particles manufactured by Daiichi Kogyo Seiyaku Co., Ltd. BYK-024 is an antifoaming agent manufactured by BYK.

[0206] <Preparation of colored ink> The components shown in Tables 1 to 3 (components other than water in the "Components other than water in colored ink (mass %)" column) were mixed with water to prepare colored ink.

[0207] In Tables 1 to 3, PG is propylene glycol as an organic solvent. TEGO wet 280 is a substrate wetting agent manufactured by Evonik. As the dispersion of acrylic resin particles, Neocryl A-1105 (solid content concentration: 50.0 mass%) manufactured by DSM was used. As the magenta PR122 pigment dispersion, APD1000Magenta (pigment concentration: 14.0 mass%) manufactured by Fujifilm Imaging Colorants was used. As the magenta PR254 pigment dispersion, APD1000Red (pigment concentration: 14.3 mass%) manufactured by Fujifilm Imaging Colorants was used. As the magenta PR150 pigment dispersion, the one prepared as follows was used.

[0208] (Preparation of magenta PR150 pigment dispersion) - Preparation of pigment dispersant P1 - 965 g of dipropylene glycol was added to a 5000 mL three-necked flask equipped with a stirrer and a cooling tube, and heated to 85°C under a nitrogen atmosphere. Solution I obtained by dissolving 640 g of benzyl methacrylate, 340 g of methacrylic acid, and 19.94 g of 2-mercapto propionic acid in 370.28 g of dipropylene glycol, and Solution II obtained by dissolving 17.69 g of t-butyl peroxy-2-ethylhexanoate (product name: "Perbutyl O", manufactured by NOF Corporation) in 221.17 g of dipropylene glycol were each prepared. Solution I and Solution II were each added dropwise to the above three-necked flask over 4 hours and 5 hours, respectively. Here, the dropwise addition of Solution I and Solution II started simultaneously. After completion of the dropwise addition, the reaction was further continued for 2 hours. The disappearance of the monomers was 1 confirmed by 1H-NMR. The obtained reaction solution was heated to 70°C, and then 248.02 g of a 50 mass% potassium hydroxide aqueous solution was added thereto. Further, 107.48 g of dipropylene glycol and 75.52 g of pure water were added and stirred to obtain a 37 mass% solution of the random polymer. This random polymer was used as pigment dispersant P1. The structural units constituting the obtained random polymer are 1The results were confirmed by 1H-NMR. The weight-average molecular weight (Mw) was also determined by GPC. The weight-average molecular weight (Mw) of the obtained pigment dispersant P1 was 8400, and the acid value was 221.7 mgKOH / g.

[0209] -Preparation of Magenta PR150 Pigment Dispersion- 150 parts by mass of pigment dispersant P1 was dissolved in water to prepare a polymer aqueous solution with a concentration of pigment dispersant P1 of approximately 25% by mass. 180 parts by mass of the obtained polymer aqueous solution was mixed with 90 parts by mass of magenta pigment PR-150 (FUJI FAST CARMINE 520, manufactured by Fuji Pigment Co., Ltd.) and 171.9 parts by mass of water to obtain a mixture. Potassium hydroxide aqueous solution was added to the mixture to adjust the pH to 8.7 after neutralization. The pH was measured at 25°C using a pH meter (model: WM-50EG, manufactured by Toa DDK Co., Ltd.). Next, the neutralized mixture was subjected to a dispersion treatment for 3 hours using a bead mill (bead diameter: 0.1 mmφ, zirconia beads). This yielded a magenta pigment dispersion (uncrosslinked dispersion) in which the magenta pigment was dispersed by pigment dispersant P1. The pigment concentration of the uncrosslinked dispersion was 15% by mass. Next, to 136 parts by mass of the uncrosslinked dispersion, 3.00 parts by mass of trimethylolpropane polyglycidyl ether (product name "Denacol EX-321", manufactured by Nagase ChemteX Corporation) and 32.8 parts by mass of an aqueous boric acid solution (boric acid concentration: 4% by mass) were added as a crosslinking agent. The mixture was reacted at 70°C for 6 hours and then cooled to 25°C. This resulted in a magenta pigment dispersion (crosslinked dispersion) in which the pigment dispersant P1 was crosslinked and the magenta pigment was dispersed by the pigment dispersant P1a. Here, the pigment dispersant P1a is a polymer in which the pigment dispersant P1 has been crosslinked by the crosslinking agent. Deionized water was added to the crosslinked dispersion so that the pigment concentration was 15% by mass. The cross-linked dispersion to which deionized water was added as described above was subjected to ultrafiltration by flowing it at a flow rate of 600 mL per minute through an ultrafiltration apparatus (cross-flow type ultrafilter (UF), manufactured by Sartorius) equipped with a polyethersulfone (PESU) membrane (micropore size: 0.1 μm). At this time, the liquid temperature was adjusted to 25°C, and ultrafiltration was performed 10 times, with each pass representing a volume ratio of 1 of the initial liquid. Deionized water was added to achieve a pigment concentration of 15% by mass. This yielded a magenta PR150 pigment dispersion. The acid value of the pigment dispersant P1a (crosslinked polymer) contained in the magenta PR150 pigment dispersion was 105 mgKOH / g.

[0210] <Preparation of white ink> White ink was prepared by mixing the components shown in Tables 1 to 3 (components other than water in white ink (mass %)) with water.

[0211] In Tables 1 to 3, As the dispersion of acrylic resin particles, we used Neocryl A-1105 (solid content concentration 50.0% by mass) manufactured by DSM. As the acrylic water-soluble polymer, we used Solsperse 43000 (solids content 50.0% by mass) manufactured by Lubrizol. The aqueous white pigment dispersion and the aqueous white pigment crosslinked dispersion were prepared as follows.

[0212] (Water-based white pigment dispersion) -Synthesis of polymer dispersant (block polymer 1)- Block polymer 1 was synthesized as a polymer dispersant, referring to Synthesis Example 8 in Japanese Patent Publication No. 2015-83688. Details are shown below. A reaction apparatus consisting of a 1 L separable flask equipped with a stirrer, a backflow condenser, a thermometer, and a nitrogen inlet tube, Diethylene glycol dimethyl ether (266 parts by mass; polymerization solvent), 2-Iodo-2-cyanopropane (6.2 parts by mass; polymerization initiation compound), Methyl methacrylate (MMA) (120 parts by mass; monomer), Acrylic acid (AA) (28.8 parts by mass; monomer), Cyclohexyl methacrylate (CHMA) (67.2 parts by mass; monomer), Azobisdimethylisovaleronitrile (7.9 parts by mass), and 2-t-butyl-4,6-dimethylphenol (0.7 parts by mass; catalyst) The mixture was added and stirred while flowing nitrogen through it. Next, the temperature of the mixture in the reaction apparatus (reaction temperature) was raised to 70°C, and polymerization was carried out for 3 hours to obtain polymerization solution A containing the MMA / AA / CHMA copolymer. After 3 hours, a sample of polymerization solution A was taken and its solid content was measured. It was found to be 42.0% by mass, confirming that most of the monomers had polymerized. Furthermore, when the molecular weight of the MMA / AA / CHMA copolymer was measured using GPC, the weight-average molecular weight (Mn) was found to be 7,500. The acid value of this MMA / AA / CHMA copolymer was 101.0 mgKOH / g.

[0213] Next, a mixture of benzyl methacrylate (BzMA) (35.2 parts by mass; monomer) and V-65 (0.3 parts by mass; radical generator) was added to polymerization solution A, and polymerization was carried out at 70°C for 3 hours to obtain polymerization solution B containing block polymer 1 as a polymer dispersant. Here, block polymer 1 is a block polymer comprising block A, which is an MMA / AA / CHMA copolymer, and block B, which is a BzMA homopolymer. When the solid content of the obtained polymerization solution B was measured, it was found to be 43.2% by mass, confirming that most of the monomers had polymerized. Furthermore, the Mw of block polymer 1 was 8,500, and its acid value was 89.3 mgKOH / g.

[0214] <Preparation of aqueous white pigment dispersion> The above block polymer 1 (136.4 parts by mass), butyl carbitol (163.6 parts by mass), and C.I. Pigment White 6 (trade name "JR-405", titanium dioxide particles, manufactured by Tayca Corporation) (450 parts by mass) as a white pigment were blended and stirred with a disper. Next, using a horizontal media disperser, the white pigment was sufficiently dispersed to obtain an oily pigment dispersion. The average particle diameter of the white pigment dispersed in the oily pigment dispersion was 290 nm. The viscosity of the oily pigment dispersion was 86.3 m3Pa·s. Next, while stirring the above oily pigment dispersion (700 parts by mass) using a disper, a mixed solution consisting of potassium hydroxide (4.0 parts by mass) and water (341 parts by mass) was gradually added thereto for neutralization. Thereafter, using a horizontal media disperser, the white pigment was sufficiently dispersed to obtain a pigment dispersion. Next, ultrafiltration was performed on the obtained pigment dispersion using an ultrafiltration device (crossflow type ultrafilter (UF), manufactured by Sartorius) by flowing ion-exchanged water at a flow rate of 600 mL per minute for 1 minute. The liquid temperature was maintained at 25°C, and ultrafiltration was performed 10 times with one time being one-fold the volume of the charged liquid. Ion-exchanged water was added to obtain an aqueous white pigment dispersion having a pigment concentration of 45% by mass and a pigment dispersant block polymer concentration of 3.7% by mass.

[0215] (Aqueous white pigment crosslinked dispersion) -Synthesis of uncrosslinked polymer dispersant N1- 965 g of dipropylene glycol was added to a 5000 mL three-necked flask equipped with a stirrer and a cooling tube, and heated to 85°C under a nitrogen atmosphere. Solution I obtained by dissolving 640 g of benzyl methacrylate, 340 g of methacrylic acid, and 19.94 g of 2-mercaptopropionic acid in 370.28 g of dipropylene glycol, and Solution II obtained by dissolving 17.69 g of t-butylperoxy-2-ethylhexanoate (product name "Perbutyl O", manufactured by NOF Corporation) in 221.17 g of dipropylene glycol, were each prepared. Solution I was added dropwise to the three-necked flask over 4 hours, followed by Solution II over 5 hours. After the dropwise addition was complete, the reaction was allowed to continue for another 2 hours. The disappearance of monomers was confirmed by 1H-NMR. The resulting reaction solution was heated to 70°C, 248.02 g of 50% potassium hydroxide aqueous solution was added, followed by 107.48 g of dipropylene glycol and 75.52 g of pure water, and the mixture was stirred to obtain a 37% random polymer solution. This random polymer was used as the uncrosslinked polymer dispersant N1. The structural units constituting the obtained random polymer (i.e., uncrosslinked polymer dispersant N1) were confirmed by 1H-NMR. The weight-average molecular weight (Mw) was also determined by GPC. The weight-average molecular weight (Mw) of the obtained uncrosslinked polymer dispersant N1 was 8400, and the acid value was 221.7 mgKOH / g.

[0216] -Preparation of white pigment dispersion N using uncrosslinked polymer dispersant N1- Uncrosslinked polymer dispersant N1 (150 parts by mass) was dissolved in water to prepare a polymer solution with a concentration of 25% by mass of uncrosslinked polymer dispersant N1. 96 parts by mass of the above polymer solution, 300 parts by mass of CI Pigment White 6 (product name "JR-405", titanium dioxide particles, manufactured by Teika Co., Ltd.), a white pigment, and 270 parts by mass of water were mixed to obtain a mixture. Potassium hydroxide aqueous solution was added to the obtained mixture to adjust the pH to 8.7 after neutralization. The pH was measured at 25°C using a pH meter (model: WM-50EG, manufactured by Toa DDK Co., Ltd.). Next, the mixture after neutralization was subjected to a dispersion treatment for 3 hours using a bead mill (bead diameter: 0.1 mmφ, zirconia beads). This yielded a white pigment dispersion N (uncrosslinked dispersion) in which the white pigment was dispersed by the uncrosslinked polymer dispersant N1. The pigment concentration of the uncrosslinked dispersion was 45% by mass, and the concentration of the uncrosslinked polymer dispersant N1 was 3.6% by mass.

[0217] -Preparation of an aqueous white pigment crosslinked dispersion using crosslinked polymer dispersant L1- To 136 parts by mass of a white pigment dispersion N (uncrosslinked dispersion) in which a white pigment is dispersed by an uncrosslinked polymer dispersant N1, 2.70 parts by mass of trimethylolpropane polyglycidyl ether (product name "Denacol EX-321", manufactured by Nagase ChemteX Corporation) and 29.5 parts by mass of an aqueous boric acid solution (boric acid concentration: 4% by mass) were added as crosslinking agents. The mixture was reacted at 70°C for 6 hours and then cooled to 25°C. This crosslinked the uncrosslinked polymer dispersant N1 in the dispersion to form a crosslinked polymer dispersant L1, and a crosslinked dispersion was obtained in which the white pigment is dispersed by the crosslinked polymer dispersant L1. To the obtained crosslinked dispersion, deionized water was added to achieve a pigment concentration of 15% by mass. The crosslinked dispersion with added deionized water was ultrafiltered through an ultrafiltration apparatus (cross-flow type ultrafilter (UF), manufactured by Sartorius) equipped with a polyethersulfone (PESU) membrane (micropore size: 0.1 μm) at a flow rate of 600 mL per minute. At this time, the liquid temperature was adjusted to 25°C, and ultrafiltration was performed eight times, with each ultrafiltration cycle being 1x the volume of the initial liquid. Next, deionized water was added to achieve a white pigment concentration of 45% by mass. This yielded an aqueous white pigment crosslinked dispersion. The acid value of the crosslinked polymer dispersant L1 contained in the aqueous white pigment crosslinked dispersion was 105 mg KOH / g. The concentration of the crosslinked polymer dispersant L1 was 3.6% by mass. The crosslinked polymer dispersant L1 is a crosslinked polymer obtained by crosslinking the uncrosslinked polymer dispersant N1 with polyethylene glycol diglycidyl ether as a crosslinking agent.

[0218] [Examples 3-17, Comparative Examples 1-3] <Image Recording> As a non-permeable substrate (hereinafter also simply referred to as "substrate"), a polyethylene terephthalate (PET) substrate (product name "FE2001", manufactured by Futamura Chemical Co., Ltd., thickness 12 μm, width 100 mm, length 240 mm) was prepared.

[0219] An image recording device was prepared that includes a transport mechanism for transporting the substrate, and, in the order of upstream of the substrate transport direction, a wire bar coater for applying pretreatment liquid, a first inkjet head for applying colored ink, and a second inkjet head for applying white ink.

[0220] Both the first and second inkjet heads were 1200 dpi / 20-inch wide piezo full-line heads. Here, dpi stands for dots per inch.

[0221] Both the first and second inkjet heads are line heads in which the heads are aligned in a direction perpendicular to the substrate transport direction (i.e., in the width direction of the substrate). For each of the above inkjet heads, we used the Samba G3L (manufactured by FUJIFILM DIMATIX).

[0222] The substrate, pretreatment solution, colored ink, and white ink were set in the image recording device described above. The pretreatment solution, colored ink, and white ink were applied to the substrate under conditions that the areas to which the pretreatment solution was applied, the areas to which the colored ink was applied, and the areas to which the white ink was applied overlapped in a planar view, and an image was recorded. This resulted in obtaining an image recording.

[0223] The substrate was moved at a constant speed of 50 m / min while the pretreatment solution was applied to the substrate using a wire bar coater. The amount of pretreatment solution applied was 1.5 g / m². 2 That's what I decided. The mass of pretreatment solution applied is the mass of the applied pretreatment solution divided by the area of ​​the region to which the pretreatment solution was applied.

[0224] For the areas where the pretreatment solution had been applied, the pretreatment solution was dried with hot air using a dryer under the conditions described in Tables 1 to 3. The time from the completion of applying the pretreatment solution to the start of hot air drying was as shown in the "Time to Drying" column in Tables 1 to 3. The residual water content after drying of the treatment solution shown in Tables 1-3 is the value obtained from measurements using a Karl Fischer moisture meter.

[0225] After the pretreatment solution had dried, the substrate was moved at a constant speed of 50 m / min. Colored ink was ejected from the first inkjet head onto the dried pretreatment solution to create a solid image, and white ink was ejected from the second inkjet head onto the applied colored ink. At this time, the white ink was applied to the entire area of ​​the colored ink on the substrate. In other words, the areas to which both inks were applied were the same.

[0226] Here, the ejection conditions for both the colored ink and the white ink were set to a resolution of 1200 dpi × 1200 dpi (dots per inch) and a frequency as described in the examples (Example 1 had an ejection frequency of 39.37 kHz). The droplet size of the colored ink is 3.0 nanograms, and the applied mass of colored ink is 6.7 g / m². 2 That's what I decided. The droplet size of the white ink is 3.0 nanograms, and the applied mass of white ink is 6.7 g / m². 2 That's what I decided. Both the colored and white inks used were degassed through a degassing filter and heated to 30°C.

[0227] White ink applied to a colored ink on a substrate was subjected to infrared (IR) drying using an infrared (IR) irradiation device (PLC-328, manufactured by Noritake Co., Ltd.) under the conditions described in Tables 1 to 3 for the substrate surface temperature. Subsequently, hot air drying was performed using a dryer under the conditions described in Tables 1 to 3. The time from the completion of coloring ink application to the start of IR drying was as shown in the "Drying Time" column in Tables 1 to 3. The amounts of residual solvent after drying in Tables 1 to 3 were obtained by gas chromatography.

[0228] Based on the above, an image recording material was obtained in which a colored image and a white image are arranged in this order on a non-permeable substrate.

[0229] The surface roughness Ra (i.e., arithmetic mean roughness Ra as defined in JIS B0601:2001) of white images on colored images in image recordings was measured using a KEYENCE VK-9710 color 3D laser microscope. The results are shown in Tables 1-3.

[0230] <Evaluation of Lamination Strength> (Preparation of samples for evaluating laminate strength) From the image recording obtained above, a 200mm long x 100mm 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. The resulting laminate was aged at 40°C for 48 hours.

[0231] (Laminate strength evaluation) 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 for the evaluation of the laminate strength between the image in the image recording and the laminating substrate. The results are shown in Tables 1-3. The above tensile tests were performed using a tensile testing machine (TENSILON RTM-25, manufactured by Orientec Co., Ltd.). In the evaluation criteria below, rank A represents the best lamination strength.

[0232] -Evaluation criteria for laminate strength (L strength)- AA: The lamination strength between the image recording material and the laminating substrate is 2N / 15mm or higher. A: The lamination strength between the image recording material and the laminating substrate is 1.5N / 15mm or higher and less than 2N / 15mm. B: The lamination strength between the image recording and the laminating substrate is 1 N / 15 mm or more and less than 1.5 N / 15 mm. C: 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. D: The lamination strength between the image recording and the laminating substrate is less than 0.5 N / 15 mm.

[0233] [Examples 1 and 2] The pretreatment solution was not used. The components of the colored ink were changed as shown in Table 1, and, The colored ink on the substrate was dried under the conditions described in Table 1 after the application of the colored ink and before the application of the white ink. The same procedure as in Example 3 was followed, except for the exceptions. The results are shown in Table 1.

[0234] [Example 18] The procedure was the same as in Example 3, except that the colored ink on the substrate was dried under the conditions described in Table 2 after the application of the colored ink but before the application of the white ink. The results are shown in Table 2.

[0235] [Examples 19 and 20] The components of the pretreatment solution were changed as shown in Table 2, and The procedure was the same as in Example 3, except that the colored ink on the substrate was dried under the conditions described in Table 2 after the application of the colored ink but before the application of the white ink. The results are shown in Table 2.

[0236] [Table 1]

[0237] [Table 2]

[0238] [Table 3]

[0239] As shown in Tables 1 to 3, the inkjet recording methods of Examples 1 to 20, which include the steps of preparing a white ink containing water and a white pigment, preparing a colored ink containing water and a colored pigment, applying the colored ink to a non-permeable substrate by an inkjet method to obtain a colored image, and applying the white ink to the colored image by an inkjet method to obtain a white image with a surface roughness Ra of 0.10 μm to 0.40 μm, have been confirmed to produce an image recording material in which a colored image and a white image are arranged in this order on a non-permeable substrate, and which exhibits excellent lamination strength when a laminating substrate is laminated onto the white image.

[0240] In contrast, in Comparative Examples 1 and 3, where the surface roughness Ra of the obtained white image was less than 0.10 μm, and in Comparative Example 2, where the surface roughness Ra of the obtained white image was greater than 0.40 μm, the lamination strength decreased in all cases.

[0241] The results from Examples 3 to 6 show that when the surface roughness of the white image is Ra 0.15 μm to 0.30 μm (Examples 4 and 5), the laminate strength is particularly excellent.

[0242] The results from Examples 3 and 13 show that when the white ink further contains resin particles (Example 3), it exhibits particularly excellent lamination strength. Example 13 is an example in which a water-soluble polymer is used instead of resin particles.

[0243] The results from Examples 7 and 8 show that when the time from the completion of white ink application to the start of heat drying is 10 seconds or less (Example 7), the laminate strength is particularly excellent.

[0244] From the results of Examples 1 and 18, it can be seen that when the process includes a step of preparing a pretreatment solution containing water and a coagulant, and a step of applying the pretreatment solution to a non-permeable substrate, which is provided before the step of obtaining a colored image (Example 18), the laminate strength is particularly excellent.

[0245] The disclosure of Japanese Patent Application No. 2021-156435, filed on 27 September 2021, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually described as being incorporated by reference.

Claims

1. An inkjet recording method for producing an image recording material used to obtain a laminate by laminating a laminating substrate onto the white image, wherein a colored image and a white image are arranged in this order on a non-permeable substrate, the surface roughness Ra of the white image is 0.10 μm to 0.40 μm, and a laminating substrate is laminated onto the white image. A step of preparing a white ink containing water and white pigment, A step of preparing a colored ink containing water and coloring pigments, A step of applying the colored ink to a non-permeable substrate by an inkjet method to obtain a colored image, The process involves applying the white ink to the colored image by an inkjet method to obtain a white image having a surface roughness Ra of 0.10 μm to 0.40 μm. Includes, The average particle size of the white pigment is between 200 nm and 550 nm. The content of the white pigment in the white ink is 10% by mass or more and 25% by mass or less, relative to the total amount of the white ink. The amount of the white pigment in the resulting white image is 0.7 g / m² or more. Inkjet recording method.

2. The inkjet recording method according to claim 1, wherein the surface roughness Ra of the white image is 0.15 μm to 0.30 μm.

3. The inkjet recording method according to claim 1 or claim 2, wherein the white ink further contains resin particles.

4. The step of obtaining the aforementioned white image is: The process involves applying the white ink to the colored image using an inkjet method, The white ink applied to the colored image is heated and dried under conditions that the time from the completion of application to the start of heating and drying is 10 seconds or less to obtain the white image. including, The inkjet recording method according to claim 1 or claim 2.

5. The aforementioned heat drying process is carried out within 70 seconds of the start of heat drying until the amount of residual solvent in the white ink applied to the colored image is 0.10 g / m². ２ The inkjet recording method according to claim 4, performed under the following conditions.

6. The process of obtaining the aforementioned colored image is as follows: The colored ink is applied to the non-permeable substrate by an inkjet method, The colored ink applied to the non-permeable substrate is given a residual solvent amount of 0.10 g / m². ２ The colored image is obtained by heating and drying under the following conditions: including, The inkjet recording method according to claim 1 or claim 2.

7. Furthermore, A step of preparing a pretreatment solution containing water and a coagulant, A step provided before the step of obtaining the colored image, comprising applying the pretreatment liquid onto the non-permeable substrate, Includes, The step of obtaining the colored image involves applying the colored ink to the area on the non-permeable substrate to which the pretreatment liquid has been applied, thereby obtaining the colored image. The inkjet recording method according to claim 1 or claim 2.

8. The step of applying the aforementioned pretreatment solution is: Applying the pretreatment solution onto the non-permeable substrate, The pretreatment liquid applied to the non-permeable substrate has a remaining water content of 0.03 g / m². ２ The following conditions must be met for heating and drying: including, The inkjet recording method according to claim 7.

9. A step of obtaining an image recording material in which the colored image and the white image are arranged in this order on the non-permeable substrate by the inkjet recording method according to claim 1 or claim 2, A step of obtaining a laminate by laminating a laminating substrate onto the white image of the image recording material, A method for manufacturing a laminate containing [the specified substance].

10. Used in the inkjet recording method described in claim 7, The system includes a transport mechanism for transporting the non-permeable substrate, The system comprises, in this order, a wire bar coater for applying the pretreatment liquid, a first inkjet head for applying the colored ink, and a second inkjet head for applying the white ink, starting from the upstream side in the transport direction of the non-permeable substrate. Inkjet recording device.

Images