JP2013056493A - Method for producing inkjet recording material - Google Patents

Abstract

[PROBLEMS] To provide excellent ink absorbability, color developability and water resistance of an image area in a water-based ink jet printer, and there is no blurring or cracking of an image even when stored under high humidity. Disclosed is a method for producing an ink jet recording material which can obtain an ink jet recording material capable of obtaining excellent print quality in a short time.
In a method for producing an ink jet recording material comprising coating an ink-receiving layer containing at least one hydrophilic polymer and a crosslinking agent on a non-water-absorbing support, the ink-receiving layer is applied and dried. A method for producing an ink jet recording material, wherein an aging treatment is later performed in a reduced pressure environment having an atmospheric pressure of 800 hPa or less.
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Description

  The present invention relates to a method for producing an ink jet recording material. More specifically, the present invention relates to an ink jet recording material that is excellent in ink absorbability in a water-based ink jet printer and that does not cause cracks in an image area after printing. The present invention relates to a method for manufacturing an ink jet recording material that can be manufactured well.

  The ink jet method as an image output method is widely used not only for general consumers such as photographic use but also for industrial use, and its use is expanding more and more. In general consumer applications, water-based inks are the mainstream, although there are differences between dye inks and pigment inks. In industrial applications, there are a wide variety of inks, and not only water-based inks but also many types of non-water-based inks such as solvent-based inks, thermosetting inks called ultraviolet curable inks and latex inks are used.

  From the viewpoint of the weather resistance of the output image, the non-aqueous ink is generally superior to the aqueous ink. Further, there are many non-aqueous inks that solidify on the surface of the recording material and ink media that have high volatility, and there is a general merit that there are wide choices of recording materials. On the other hand, the recording material for water-based ink needs to absorb all of the ejected ink, and there are restrictions on the recording material that can be used. However, the water-based ink jet printer has a great advantage that it is very easy to operate in the working environment because it does not require a large facility such as an exhaust device necessary for the solvent ink and the odor problem does not occur.

  The recording material for the water-based ink jet recording system needs to absorb ink that is shot in during image formation, and the recording material that requires high color development has an ink receiving layer on the support. The ink receiving layer is roughly classified into two types, one is a porous ink receiving layer mainly composed of an inorganic pigment and a hydrophilic polymer, and the other is an ink receiving layer mainly composed of a hydrophilic polymer. The former ink-receiving layer is called a void type (or microporous type) because it absorbs ink in voids formed by inorganic pigments, and the latter ink-receiving layer is an ink that is formed by the swelling of a hydrophilic polymer. It is called a swelling type (or polymer type) because it absorbs water.

  As the inorganic pigment contained in the void-type ink receiving layer, from the viewpoint of obtaining excellent gloss, image clarity, and color developability, vapor phase method silica or wet method in which the average secondary particle size is dispersed or pulverized to 500 nm or less It has been proposed to use inorganic fine particles such as silica as a pigment component of the ink receiving layer. Examples of the use of the vapor phase method silica include, for example, JP-A-10-119423, JP-A-2000-21235, JP-A-2000-309157, and the like. No. 9-286165, JP-A-10-181190, and the like. Examples of use of pulverized gel method silica include, for example, JP-A No. 2001-277712, and examples of inorganic pigments other than silica include use of alumina or alumina hydrate, for example, JP-A No. 62-174183. JP-A-2-276670, JP-A-5-32037, JP-A-6-199034, and the like.

  The void-type ink receiving layer absorbs ink in voids formed by aggregates of inorganic fine particles. In order to maintain this void, a hydrophilic polymer or the like is used as a binder, and in many cases, a hydrophilic polymer cross-linking agent is also used. For example, JP-A-2003-89263, JP-A-2001-96903, and JP-A-2003-291503 (Patent Documents 1 to 3) describe that the recording material is heated for the purpose of promoting the crosslinking reaction. Have been described. If this crosslinking reaction is insufficient, the image tends to bleed due to the influence of humidity when the printed recording material is stored. Or the ink absorbability may be insufficient. Japanese Patent Application Laid-Open No. 2006-31277 (Patent Document 4) discloses that an inorganic fine particle is coated on the outermost surface of the ink receiving layer without containing a polymer binder, and this inorganic fine particle is fused. It has been proposed to perform a temperature treatment. However, since these heating processes require a long time, there is a problem that productivity is remarkably lowered.

  On the other hand, as the swelling type ink receiving layer, there are various types of cellulose derivatives such as gelatin, polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, acrylic acid polymers, and cationic polyurethane resins. An ink receiving layer containing a hydrophilic polymer as a main component has been proposed. Among them, the cationic polyurethane resin is known as an ink jet receiving agent capable of obtaining water resistance and glossiness at the same time as high ink jet aptitude, and for example, JP 2009-46780 A (Patent Document 5) and JP 2007-276392 A. JP-A 2007-168164, JP-A 2005-74880, etc. propose an ink jet recording sheet using a cationic polyurethane resin by various methods.

  The swelling type ink receiving layer is mainly composed of a hydrophilic polymer as described above. However, it is hydrophilic for the purpose of improving the water resistance of the ink receiving layer and suppressing cracks in the printed part. The polymer may be cross-linked. In addition, in order to develop better ink absorbency, a heating process may be performed to accelerate the dehydration reaction. The purpose of this is to improve the ink absorbability and water resistance of the recording material during printing by removing the hydrated water adsorbed on the hydrophilic polymer. Such a heating process for promoting the cross-linking reaction requires a long time as in the case of the void-type ink receiving layer, and thus has a problem that productivity is remarkably lowered.

  In addition, when a shrink film is used as a support, the recording material shrinks when the heating process is performed. Therefore, it takes a very long time to complete the crosslinking reaction and obtain a predetermined print quality. There was a problem that.

JP 2003-89263 A JP 2001-96903 A JP 2003-291503 A JP 2006-31277 A JP 2009-46780 A

  An object of the present invention is to provide a production method for obtaining an ink jet recording material capable of obtaining excellent print quality in printing with a water-based ink jet printer in a short time. The excellent print quality here means that the ink-jet recording material is excellent in ink absorbency and bleed resistance under high humidity, and the ink absorption is good in the case of swelling ink-jet recording material. And excellent water resistance of the image area, and there is no cracking of the image area even when stored under high humidity.

The above object of the present invention has been achieved by the following means.
(1) In a method for producing an ink jet recording material obtained by coating an ink-receiving layer containing at least one hydrophilic polymer and a crosslinking agent on a non-water-absorbing support, the ink-receiving layer is applied and dried. A method for producing an ink jet recording material, comprising performing an aging treatment in a reduced pressure environment having an atmospheric pressure of 800 hPa or less.
(2) The method for producing an ink jet recording material according to (1), wherein the non-water-absorbing support is a shrink film, and the aging treatment is performed under a condition of 25 ° C. or lower.
(3) The method for producing an ink jet recording material according to (1), wherein the ink receiving layer mainly contains inorganic fine particles.
(4) The ink receiving layer contains a cationic polyurethane resin, polyvinyl alcohol and boric acid or a salt thereof (however, when the ink receiving layer contains inorganic fine particles, the content of the inorganic fine particles is the total amount of the ink receiving layer). (The solid content is 5% by mass or less) The method for producing an ink jet recording material according to the above (1).

  According to the method for producing a recording material of the present invention, an ink jet recording material capable of obtaining excellent print quality in printing with a water-based ink jet printer can be obtained in a short time.

Hereinafter, the present invention will be described in detail.
The aging treatment in the present invention is a step of promoting the crosslinking reaction between the hydrophilic polymer and the crosslinking agent. The present inventor has found that this crosslinking reaction is promoted by being subjected to an aging treatment under a reduced pressure environment, and has reached the present invention. The reduced pressure environment in the present invention is 800 hPa or less, preferably 400 hPa or less, and more preferably 110 hPa or less. When the atmospheric pressure during the aging treatment is higher than 800 hPa, the effect of promoting the crosslinking reaction due to the reduced pressure cannot be found so much, which is not preferable.

  In the present invention, the aging treatment under reduced pressure is a step of promoting the crosslinking reaction of the hydrophilic polymer in the ink receiving layer as described above, and a heating treatment may be performed as necessary. The temperature of the heating treatment needs to be appropriately adjusted with respect to the properties of the non-absorbing support, the properties of the substance constituting the ink receiving layer, the strength of the ink receiving layer, and the like. For example, when a non-absorbent support having a resin coated on both sides of a base paper is used, it is necessary to handle the recording material at a temperature lower than the softening point of the resin.

  When using a film obtained by stretching a polyester resin as a non-absorbent support, it is not possible to ignore a decrease in dimensional stability due to thermal shrinkage at high temperatures. It is more preferable. When a shrink film is used as the non-water-absorbing support, the heat shrinkability of the shrink film is remarkable, so that the heating treatment is not preferable, and it is preferable to perform the aging treatment at 25 ° C. or less.

  In the ink receiving layer mainly containing the inorganic fine particles of the present invention, “mainly containing the inorganic fine particles” means that the inorganic fine particles are contained in an amount of 50% by mass or more based on the total solid content of the ink receiving layer, preferably It is contained 60 mass% or more, More preferably, it is contained 65 mass% or more. The upper limit is preferably about 95% by mass. By containing the inorganic fine particles as a main component, a so-called void-type ink receiving layer having a high porosity is obtained, and ink absorbability is improved. In addition, the average secondary particle diameter of the inorganic fine particles is preferably 500 nm or less from the viewpoints of glossiness, image clarity, and color developability.

  Examples of the inorganic fine particles having an average secondary particle diameter of 500 nm or less that are preferably contained in the void-type ink receiving layer of the present invention include light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, titanium dioxide, zinc oxide, and zinc hydroxide. , Calcium silicate, magnesium silicate, synthetic silica, alumina, alumina hydrate, magnesium hydroxide and the like, and two or more of these may be mixed. Among these, synthetic silica, alumina or alumina hydrate is more preferable, and these inorganic fine particles are advantageous in terms of cost because a high printing density and a clear image can be obtained. More preferable inorganic fine particles in the present invention are amorphous synthetic silica, alumina, or alumina hydrate.

  Amorphous synthetic silica can be roughly classified into wet method silica and gas phase method silica depending on the production method. Vapor phase silica is also called a dry method as opposed to a wet method, and is generally made by a flame hydrolysis method. Specifically, a method of making silicon tetrachloride by burning with hydrogen and oxygen is generally known, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone or in silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state. Vapor phase silica is commercially available as Aerosil from Nippon Aerosil Co., Ltd.

  Wet method silica is further classified into precipitation method silica, gel method silica, and sol method silica according to the production method. Precipitated silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions, and the silica particles that have grown are agglomerated and settled, and are then commercialized through filtration, water washing, drying, pulverization and classification. The secondary particles of silica produced by this method become loosely agglomerated particles, and particles that are relatively easy to grind are obtained. Precipitated silica is commercially available, for example, as a nip seal from Tosoh Silica. Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During the ripening, the fine particles dissolve and reprecipitate so as to bond the other primary particles, so that the clear primary particles disappear and form relatively hard aggregated particles having an internal void structure. For example, commercially available as Toyo Silica Co., Ltd. as nip gel, from Mizusawa Chemical Industry Co., Ltd. as Mizukasil, from Grace Japan Co., Ltd. as syloid and silo jet. The sol silica is also called colloidal silica, which is obtained by heating and aging silica sol obtained through metathesis of sodium silicate acid or the like through an ion exchange resin layer. For example, it is commercially available as Snowtex from Nissan Chemical Industries, Ltd. Yes.

The vapor phase method silica that can be used in the void-type ink receiving layer of the present invention will be described. The average primary particle diameter of the vapor-phase process silica used in the present invention is preferably 30 nm or less, and preferably 15 nm or less in order to obtain higher gloss. More preferably, an average primary particle diameter of 3 to 15 nm and a specific surface area by BET method of 200 m ² / g or more (preferably 250 to 500 m ² / g) are used. The average primary particle diameter as used in the present invention refers to the average particle diameter obtained by observing fine particles with an electron microscope and taking the diameter of a circle equal to the projected area of each of 100 primary particles present within a certain area as the particle diameter of the particles. The BET method referred to in the present invention is one of the powder surface area measurement methods by the vapor phase adsorption method, and is a method for determining the total surface area of a 1 g sample from the adsorption isotherm, that is, the specific surface area. is there. Usually, nitrogen gas is often used as the adsorbed gas, and the most frequently used method is to measure the amount of adsorption from the change in pressure or volume of the gas to be adsorbed. The most prominent expression for expressing the isotherm of multimolecular adsorption is the Brunauer, Emmett, and Teller equation, called the BET equation, which is widely used for determining the surface area. The adsorption amount is obtained based on the BET equation, and the surface area is obtained by multiplying the area occupied by one adsorbed molecule on the surface.

  The average secondary particle size of the vapor phase silica mainly contained in the void-type ink receiving layer of the present invention is preferably 500 nm or less, and more preferably 10 to 300 nm. The vapor phase silica is preferably dispersed in the presence of a cationic polymer. In order to set the average secondary particle size of the vapor phase method silica to 500 nm or less, for example, the gas phase method silica and the dispersion medium are premixed by a normal propeller stirring, a turbine type stirring, a homomixer type stirring, etc., and then a ball mill, It is preferable to perform dispersion using a media mill such as a bead mill or a sand grinder, a pressure disperser such as a high-pressure homogenizer, an ultra-high pressure homogenizer, an ultrasonic disperser, a thin film swirl disperser, or the like. The average secondary particle diameter as used in the present invention can be determined by photographing an ink receiving layer of the obtained recording material with an electron microscope. For simplicity, a laser scattering type particle size distribution meter (for example, ( The number median diameter can be measured using LA920 manufactured by HORIBA, Ltd.

  Examples of the cationic polymer used for the dispersion of the vapor phase silica include polyethyleneimine, polydiallylamine, polyallylamine, alkylamine polymer, JP-A-59-20696, JP-A-59-33176, JP JP 59-33177, JP 59-1555088, JP 60-11389, JP 60-49990, JP 60-83882, JP 60-109894. JP, 62-198493, JP 63-49478, JP 63-115780, JP 63-280681, JP 1-40371, JP 6-6 No. 234268, JP-A-7-125411, JP-A-10-19376, and the like. Polymers having Moniumu base is preferably used. In particular, diallylamine derivatives are preferably used as the cationic polymer. In terms of dispersibility and dispersion viscosity, the molecular weight of these cationic polymers is preferably about 2,000 to 100,000, and particularly preferably about 2,000 to 30,000. The amount of the cationic polymer used is preferably in the range of 1 to 10% by weight relative to the vapor phase silica.

  Next, the wet method silica will be described. The wet process silica contained in the void-type ink receiving layer of the present invention is precipitated silica or gel process silica. These silica powders before pulverization preferably have an average primary particle diameter of 50 nm or less, more preferably 3 to 40 nm, and an average aggregate particle diameter (secondary particle diameter) of 5 to 50 μm. The average secondary particle diameter of the wet process silica is preferably 500 nm or less, and more preferably 10 to 300 nm. In order to set the average secondary particle size of these wet process silicas to 500 nm or less, for example, a media mill such as a ball mill, a bead mill, and a sand grinder, a pressure disperser such as a high pressure homogenizer, and an ultrahigh pressure homogenizer, an ultrasonic disperser, and It is preferable to grind in an aqueous medium using a thin film swirl type disperser or the like. The pulverization is preferably performed in the presence of a cationic compound as mentioned in the dispersion of the vapor phase silica.

  As the wet process silica that can be used in the void-type ink receiving layer of the present invention, precipitated silica is preferable. Precipitated silica is suitable for grinding because its secondary particles are loosely agglomerated particles.

  As the inorganic fine particles mainly contained in the void-type ink receiving layer of the present invention, alumina or alumina hydrate is also preferably used. Alumina or alumina hydrate is aluminum oxide or its hydrate, which may be crystalline or amorphous, and has an amorphous shape, a spherical shape, a plate shape, or the like. Either of them may be used or may be used in combination.

  As the alumina oxide that can be used in the present invention, γ-alumina, which is a γ-type crystal of aluminum oxide, is preferable, and among them, a δ group crystal is preferable. Although γ-alumina can reduce the primary particles to about 10 nm, normally, secondary particle crystals of several thousand to several tens of thousands nm are averaged by ultrasonic waves, a high-pressure homogenizer, a counter collision type jet crusher, or the like. Those having a secondary particle size of up to 500 nm or less can be preferably used, and those having a secondary particle size of about 50 to 300 nm can be used more preferably.

The alumina hydrate that can be used in the present invention is represented by a constitutional formula of Al ₂ O ₃ .nH ₂ O (n = 1 to 3). The hydrated aluminum oxide can be obtained by a known production method such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, hydrolysis of aluminate, and the like. The average secondary particle diameter of the alumina hydrate used in the present invention is preferably 500 nm or less, and more preferably 10 to 300 nm.

  Alumina and alumina hydrate that can be used in the present invention are those in which the average secondary particle diameter is dispersed to 500 nm or less by a known dispersant such as acetic acid, lactic acid, formic acid, methanesulfonic acid, hydrochloric acid, nitric acid and the like. Preferably used.

  The void-type ink receiving layer of the present invention contains a hydrophilic polymer in order to maintain the properties as a film and to obtain high transparency and high ink permeability. Examples of the hydrophilic polymer include polyvinyl alcohol, polyethylene glycol, starch, dextrin, carboxymethyl cellulose, polyvinyl pyrrolidone, polyacrylic acid ester and derivatives thereof. Preferred hydrophilic polymers are completely or partially saponified polyvinyl alcohol. It is. Particularly preferred among the polyvinyl alcohols are those having a saponification degree of 80% or more or those having a complete saponification and an average polymerization degree of 500 to 5,000.

  The mass ratio of the hydrophilic polymer to the inorganic fine particles contained in the void-type ink receiving layer of the present invention is preferably in the range of 5 to 30% by mass, particularly preferably 5 to 25% by mass.

  The void-type ink receiving layer of the present invention contains a crosslinking agent together with a hydrophilic polymer. Specific examples of the crosslinking agent include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, bis (2-chloroethylurea), 2-hydroxy-4,6-dichloro-1, 3,5-triazine, a compound having a reactive halogen as described in US Pat. No. 3,288,775, divinyl sulfone, and a reactive olefin as described in US Pat. No. 3,635,718. Compounds having N-methylol compounds as described in US Pat. No. 2,732,316, isocyanates as described in US Pat. No. 3,103,437, US Pat. No. 3,017,280 Aziridine compounds as described in U.S. Pat. No. 2,983,611, U.S. Pat. No. 3,100,70. Carbodiimide compounds as described in US Pat. No. 3,091,537, epoxy compounds as described in US Pat. No. 3,091,537, halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane, chromium alum, zirconium sulfate Inorganic cross-linking agents such as boric acid and its salts, and the like can be used alone or in combination of two or more. Among these, boric acid or a salt thereof is particularly preferable. The addition amount of the crosslinking agent is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass with respect to the hydrophilic polymer constituting the ink receiving layer.

The void-type ink receiving layer of the present invention can be provided in a plurality of layers as necessary. The solid content coating amount of the entire void-type ink receiving layer is preferably 7 to 40 g / m ² .

  In the present invention, the swelling type ink receiving layer contains a hydrophilic polymer as a main component. As the hydrophilic polymer, a water-soluble polymer or a water-dispersible polymer emulsion can be used. Examples of water-soluble polymers include cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, gelatin, dextrin, sodium polyacrylate, polyvinylpyrrolidone, polyacrylamide, polyvinyl alcohol, sodium polystyrene sulfonate, polyethylene glycol. Etc. A wide range of synthetic polymer emulsions can be used as the water-dispersible polymer emulsion. For example, acrylic acid and its ester compounds (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, t-butyl acrylate) Amyl acrylate, hexyl acrylate, octyl acrylate, etc.), α-substituted acrylic acid and its ester compounds (methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, etc.) , Acrylamide and its substitutes (butyl acrylamide, hexyl acrylamide, etc.), vinyl esters (vinyl acetate, etc.), vinyl halides (vinyl chloride, etc.), vinylidene halides (vinylidene chloride, etc.), vinyl Ether (vinyl methyl ether, vinyl octyl ether), styrene, divinylbenzene, ethylene, butadiene, vinyl polymer, polyurethane resin or the like to a vinyl monomer such as acrylonitrile as a main raw material and the like. These water-soluble polymers and water-dispersible polymer emulsions may be used in any combination. Among these, polyurethane resin is preferable from the viewpoint of ink absorbability.

  The polyurethane resin is obtained by reacting a polyisocyanate and a polyol. Examples of the polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2, 2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate Tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexane Examples include silylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, triphenylmethane triisocyanate, 1-methylbenzol-2,4,6-triisocyanate. be able to. These polycyanate compounds may be used alone or in combination of two or more.

  Known polyols can be used as the polyol used for obtaining the polyurethane resin, and examples thereof include polyether polyols, polyester polyols, polycarbonate polyols, polyacetal polyols, and polyacrylate polyols. Examples of the polyether polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-propanediol, and 3-methyl-2,4- Pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentane Diol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1, Aliphatic diols such as 10-decanediol, diethylene glycol and triethylene glycol, cyclohexane dimethanol And alicyclic diols such as cyclohexanediol, trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, pentaerythritol, tetramethylolpropane and other trivalent alcohols, polytetramethylene glycol, etc. It is done. Examples of the polyester polyol include ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanedimethanol, bisphenol A, bisphenol S, hydroquinone, or alkylene oxide addition of these compounds Body diol components and malonic acid, succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, deca Dicarboxylic acid, dodecanedicarboxylic acid, hexadecanedicarboxylic acid, maleic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, phthalic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bisphenoxyethane-p, p'-dicarboxylic acid, trimellitic acid, trimesic acid, a trimer of castor oil fatty acid, or a polycarboxylic acid thereof Polyesters obtained by condensation reaction from polycarboxylic acid components such as acid anhydride salts or ester-forming derivatives, polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone, and copolymerized polyesters thereof And the like.

  The polyurethane resin that can be used in the swelling type ink-receiving layer in the present invention is preferably cationic from the viewpoint of ink fixability, and known cationic polyurethane resins can be used. As a method for introducing a cationic group into a polyurethane resin, for example, a method of neutralizing a tertiary amino group of a polyamine used as a chain extender described later with an acid or quaternizing with a quaternizing agent, As described in JP 2007-168164 A, a polyol containing a tertiary amino group in the side chain is used, and the tertiary amino group is neutralized with an acid or quaternized with a quaternizing agent to be cationized. Methods and the like. When using a polyol containing a tertiary amino group in the side chain, a polyol not containing a tertiary amino group may be used in combination. Examples of acids that can be used for neutralizing the tertiary amino group include formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, butyric acid, lactic acid, malic acid, citric acid, tartaric acid, and malonic acid. Organic acids such as adipic acid, sulfonic acids, p-toluenesulfonic acid, methanesulfonic acid, hydroxymethanesulfonic acid and other organic sulfonic acids, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, phosphorous acid, hydrofluoric acid, etc. An inorganic acid etc. are mentioned, You may use these individually or in combination of 2 or more types. Examples of the quaternizing agent that can be used for quaternizing the tertiary amino group include dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, methyl chloride, ethyl chloride, benzyl chloride, methyl Alkyl halides such as bromide, ethyl bromide, benzyl bromide, methyl iodide, ethyl iodide, and benzyl iodide, alkyl such as methyl methanesulfonate and methyl paratoluenesulfonate, and methyl arylsulfonates, ethylene oxide, propylene Examples include epoxides such as oxide, butylene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether. That.

  Examples of the chain extender used for the purpose of adjusting physical properties such as mechanical properties and thermal properties of the polyurethane resin include polyamines and chain extenders containing active hydrogen. Examples of the chain extender for polyamines include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3, 3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, hydroxymethylaminoethylamine, hydroxyethylaminoethylamine, hydroxypropylaminopropylamine, ethylaminoethylamine, methylaminopropylamine, diethylenetriamine, dipropylene Diamines such as triamine and triethylenetetramine, hydrazines such as hydrazine, N, N'-dimethylhydrazine and 1,6-hexamethylenebishydrazine, disuccinic acid Dihydrazides such as dorazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, β-semicarbazide propionic acid hydrazide, 3-semicarbazide propylcarbazate, semicarbazide-3-semicarbazide methyl-3,5,5 -Semicarbazides such as trimethylcyclohexane. As chain extenders containing active hydrogen, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, saccharose, methylene Glycols such as glycol, glycerin and sorbitol, phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, hydrogenated bisphenol A, hydroquinone and water Is mentioned.

  As a method for producing a cationic polyurethane resin that can be used in the swelling ink-receiving layer of the present invention, a known method can be used. For example, a batch reaction method in which raw materials such as polyisocyanate and polyol are charged and reacted together and a sequential reaction method in which a part of the raw materials such as polyisocyanate and polyol are charged and reacted are included.

  Examples of the cationic polyurethane resin that can be used in the swelling type ink-receiving layer of the present invention include, for example, Pateracol series from DIC Corporation, Parasurf UP-28 and UP-36 from Ohara Palladium Chemical Co., Ltd. Moreover, what is marketed as Meiko Chemical Co., Ltd. as pass call JK-830 grade | etc., Can also be obtained and utilized.

The solid coating amount of the hydrophilic polymer that can be used in the ink-receiving layer of a swelling type of the present invention is not particularly limited, preferably ^{5~40g / m 2, 7~35g / m} 2 is particularly preferred. If it is less than 5 g / m ² , the ink absorbability may be lowered, and if it exceeds 40 g / m ² , the cost may be increased, or the curling property and transparency may be deteriorated.

  The reason why cracks occur in the printed portion when an image is output using the pigment ink on the swelling type recording material is presumed as follows. Since the solvent component in the ink is absorbed by swelling of the polymer in the swelling type ink receiving layer, the ink receiving layer expands. When the solvent component in the ink is released in the subsequent drying process, the ink receiving layer contracts. On the other hand, the pigment colorant in the ink printed and separated from the solvent component stays on the surface of the ink receiving layer to form an image. Since the ink pigment does not particularly absorb the solvent component by swelling, the volume does not change in the process from printing to drying. In this way, cracks occur due to the difference in expansion ratio between the image portion and the ink receiving layer, but in the present invention, the crosslinking reaction of the hydrophilic polymer is promoted by the aging treatment, and the expansion and contraction of the ink receiving layer can be reduced. It is presumed that cracking of the printed portion is suppressed.

  A hydrophilic polymer cross-linking agent is used in the swelling type ink receiving layer of the present invention. Various crosslinking agents described above can be used as the crosslinking agent for the hydrophilic polymer. The amount of the crosslinking agent that can be used in the swelling ink receiving layer of the present invention is not particularly limited, but is preferably 0.1 to 65% by mass with respect to the hydrophilic polymer.

The swelling ink-receiving layer of the present invention preferably contains a cationic polyurethane resin and polyvinyl alcohol together for the purpose of further improving ink absorbability. The polyvinyl alcohol in this case is preferably completely or partially saponified, and preferably has a saponification rate of 70% or more. The average degree of polymerization is preferably from 200 to 5,000. Further, modified polyvinyl alcohol such as cation-modified polyvinyl alcohol can also be used. For example, as described in JP-A-61-10383, a primary to tertiary amino group or a quaternary ammonium group can be used as polyvinyl alcohol. This is polyvinyl alcohol or the like contained in the main chain or side chain. The addition amount of polyvinyl alcohol in the present invention is preferably 10 to 90% by mass, particularly preferably 18 to 75% by mass, based on the cationic polyurethane resin. The total solid content of the cationic polyurethane resin and polyvinyl alcohol is preferably 7 to 30 g / m ² . The swelling type ink-receiving layer of the present invention may be formed by mixing the above-mentioned cationic polyurethane resin and polyvinyl alcohol to prepare a coating solution and coating it, for example, Pateracol EG-4X Since DIC (manufactured by DIC Corporation), Parasurf UP-28 (manufactured by Ohara Palladium Chemical Co., Ltd.) and the like are mixed in advance with a cationic polyurethane resin and polyvinyl alcohol, these can also be suitably used. Moreover, polyvinyl alcohol and a cationic polyurethane resin can also be added and used with respect to these commercial items.

  When the above cationic polyurethane resin and polyvinyl alcohol are used in combination, it is more preferable to use a polyvinyl alcohol crosslinking agent in combination. Examples of the polyvinyl alcohol crosslinking agent include zirconium compounds such as zirconium acetate, zirconium chloride, zirconium chloride octahydrate, zirconium zirconium chloride and the like, water-soluble organic titanium compounds such as titanium lactate, and inorganic crosslinking such as boric acid and its salts. An organic crosslinking agent such as an agent, an epoxy compound, methylol melamine, and glyoxal is known. From the viewpoints of reactivity to polyvinyl alcohol, stability of the coating solution, etc., boric acid or a salt thereof is preferable.

  The swelling ink-receiving layer of the present invention preferably contains no inorganic pigment from the viewpoints of crease resistance and coating layer transparency. The inorganic pigment can be added as required, such as a matting agent, but the amount added must be 5% by mass or less based on the solid content of the ink receiving layer. The transparency of the coating layer can be determined by applying an ink receiving layer to a transparent film base and measuring the haze of the obtained recording material with a haze meter or the like. When the haze value is 5% or less, the coating layer is considered to be transparent.

  In the swelling type ink receiving layer of the present invention, a cationic polymer similar to that used for cationization of the above-mentioned amorphous synthetic silica may be further used as an additive.

  The ink receiving layer of the present invention may contain a water-soluble polyvalent metal compound for the purpose of improving water resistance and improving the fixability of pigment ink. As the water-soluble polyvalent metal compound, a water-soluble aluminum compound and a water-soluble zirconium compound can be preferably used.

  Examples of water-soluble zirconium compounds that can be used in the present invention include zirconium acetate, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium carbonate / ammonium, zirconium carbonate / potassium, zirconium sulfate, zirconium fluoride, zirconium chloride, chloride. Zirconium octahydrate, zirconium oxychloride, hydroxyzirconium chloride and the like can be mentioned. Among these water-soluble zirconium compounds, zirconium acetate (zirconyl acetate) and zirconium oxychloride are particularly preferable.

  Examples of water-soluble aluminum compounds that can be used in the present invention include inorganic salts such as aluminum chloride or hydrates thereof, aluminum sulfate or hydrates thereof, and ammonium alum. Furthermore, a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer is known.

Among these water-soluble aluminum compounds, those that can be stably added to the coating solution for forming the ink receiving layer are preferable, and a basic polyaluminum hydroxide compound is preferably used. The main component of this compound is represented by the following formula 1, 2 or 3, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ ] ⁵⁺ , It is a water-soluble polyaluminum hydroxide that stably contains a basic and high-molecular polynuclear condensed ion such as [Al ₂₁ (OH) ₆₀ ] ³⁺ .

[Al ₂ (OH) _n Cl _6-n ] _m ·· Formula 1
[Al (OH) ₃ ] _n AlCl ₃ .. Formula 2
Al _n (OH) _m Cl _(3n−m) 0 <m <3n Formula 3

  These are the names of polyaluminum chloride (PAC) and highly basic aluminum chloride (Takibaine) from Taki Chemical Co., Ltd., and the name of polyaluminum hydroxide (Paho) from Asada Chemical Industry Co., Ltd. It is commercially available from RIKEN GREEN under the name of Purachem WT and from other manufacturers for the same purpose, and various grades are readily available. In the present invention, these commercially available products can be used as they are.

  The content of the water-soluble polyvalent metal compound is preferably in the range of 0.1 to 10% by mass with respect to the solid content coating amount of the ink receiving layer.

  The ink receiving layer of the present invention further includes a coloring dye, a coloring pigment, an ultraviolet absorber, an antioxidant, a crosslinking agent, an antifoaming agent, a leveling agent, a surfactant, an antiseptic, a fluorescent whitening agent, a viscosity stabilizer, Various known additives such as a pH adjusting agent and a matting agent can also be added.

  As a method for applying the ink receiving layer of the present invention, any method such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a reverse coater, a slide bead coater, and a slide curtain coater may be used. When two or more layers such as an ink receiving layer and other layers are provided, a multilayer coating method using a slide bead coater or a slide curtain coater is preferably used.

  The support of the ink jet recording material of the present invention must be a non-absorbent support from the viewpoint of the storage stability of the output under high humidity, and the resin coating in which at least one surface of the base paper is coated with a resin Paper, a resin film, a shrink film, etc. are mentioned. A shrink film that can be used as a support in the present invention is obtained by stretching a plastic film made of olefin resin such as polyethylene or polypropylene, vinyl chloride resin, vinylidene chloride resin, polystyrene resin, polyester resin, polyamide resin, or other resin. It is a commonly used heat shrinkable film. The thickness of these supports is 15 to 350 μm, preferably 20 to 300 μm.

  The resin-coated paper that can be used in the present invention will be described in detail. The water content of the resin-coated paper used in the present invention is not particularly limited, but it is preferably in the range of 5.0 to 9.0% by mass, more preferably 6.0 to 9.0% by mass from the curling property. Range. The moisture content of the resin-coated paper can be measured using any moisture measurement method. For example, an infrared moisture meter, an absolute dry weight method, a dielectric constant method, a Karl Fischer method, or the like can be used.

  The base paper constituting the resin-coated paper is not particularly limited, and commonly used paper can be used. For example, a smooth base paper used for a photographic support is preferable. As the pulp constituting the base paper, natural pulp, regenerated pulp, synthetic pulp or the like is used alone or in combination. This base paper is blended with additives such as sizing agent, paper strength enhancer, filler, antistatic agent, fluorescent whitening agent, and dye generally used in papermaking.

  Further, a surface sizing agent, a surface paper strength agent, a fluorescent brightening agent, an antistatic agent, a dye, an anchor agent, and the like may be applied on the surface.

Further, the thickness of the base paper is not particularly limited, but preferably has a good surface smoothness such as a paper that is compressed during or after paper making by applying pressure, etc., and its basis weight is 30 to 250 g. / M ² is preferred.

  Examples of the resin for coating the base paper include homopolymers of olefins such as low density polyethylene, high density polyethylene, polypropylene, polybutene, and polypentene, or copolymers composed of two or more olefins such as ethylene-propylene copolymer and the like. A mixture having various densities and melt viscosity indexes (melt index) can be used alone or in combination.

  In addition, in the resin of the resin-coated paper, white pigments such as titanium dioxide, zinc oxide, talc and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, zinc stearate, calcium stearate, aluminum stearate, stearin Fatty acid metal salts such as magnesium acid, antioxidants such as hindered phenol compounds, blue pigments and dyes such as cobalt blue, ultramarine blue, cecilian blue, and phthalocyanine blue, and magenta pigments such as cobalt violet, fast violet, and manganese purple It is preferable to add various additives such as dyes, dyes, fluorescent brighteners and ultraviolet absorbers in appropriate combinations.

  The main production method of the resin-coated paper is produced by a so-called extrusion coating method in which a resin is cast on a traveling base paper in a heated and melted state, and both surfaces of the base paper are coated with the resin. Further, before the resin is coated on the base paper, the base paper is preferably subjected to activation treatment such as corona discharge treatment and flame treatment. The thickness of the resin coating layer is suitably 5 to 50 μm.

An undercoat layer is preferably provided on the side of the support used in the present invention on which the ink receiving layer is applied. This undercoat layer is applied and dried in advance on the surface of the support before the ink receiving layer is applied. The undercoat layer mainly contains a water-soluble polymer or polymer latex that can form a film. Preferred are water-soluble polymers such as gelatin, polyvinyl alcohol, polyvinyl pyrrolidone and water-soluble cellulose, and particularly preferred is gelatin. Adhesion amount of the water-soluble polymer is preferably ^{10~500mg / m 2, 20~300mg / m} 2 is more preferable. Further, the undercoat layer preferably contains a surfactant and a crosslinking agent. By providing the undercoat layer on the support, it effectively works to prevent cracking when the ink receiving layer is applied, and a uniform coated surface is obtained.

  In the ink jet recording material of the present invention, on the side opposite to the support and the side opposite to the support, various types of anti-curling and various types of ink transfer can be used to further improve adhesion and ink transfer when superimposed immediately after printing. A backing layer may be provided, and an ink receiving layer may be applied to both sides of the support.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the content of this invention is not limited to an Example. Unless otherwise specified, parts and% indicate parts by mass and mass% in terms of solid content.

Example 1
<Preparation of resin-coated paper>
A 1: 1 mixture of hardwood bleached kraft pulp (LBKP) and hardwood bleached sulfite pulp (LBSP) was beaten to 300 ml with Canadian Standard Freeness to prepare a pulp slurry. As a sizing agent, alkylketene dimer is 0.5% to pulp, polyacrylamide is 1.0% to pulp, and cationized starch is 2.0% to pulp. Polyamide epichlorohydrin resin is 0 to pulp. 0.5% added and diluted with water to give a 0.2% slurry. This slurry was made with a long paper machine to a basis weight of 170 g / m ² , dried and conditioned to obtain a resin-coated base paper. A polyethylene resin composition in which 10% anatase-type titanium is uniformly dispersed in a low density polyethylene resin having a density of 0.918 g / cm ³ is melted at 320 ° C. to a paper base having a density of 35 μm. The surface was extrusion coated using a cooling roll that had been extrusion coated and finely roughened. Melted at similarly 320 ° C. The blend resin composition of the low density polyethylene resin 30 parts of a density 0.962 g / cm 70 parts high density polyethylene resin of ³ and a density 0.918 g / cm ³ on the other surface, the thickness Extrusion-coating to a thickness of 30 μm, and extrusion coating using a cooling roll having a roughened surface was used as the back surface.

The surface of the resin-coated paper was subjected to a high-frequency corona discharge treatment, and then an undercoat layer having the following composition was applied and dried so that gelatin was 50 mg / m ² to prepare a support.

<Underlayer>
Lime-processed gelatin 100 parts Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chromium alum 10 parts

On the surface provided with the undercoat layer of the resin-coated paper produced as described above, the ink receiving layer coating liquid 1 having the following composition was applied with a slide bead coater, and then the wind was blown at 5 ° C. to immobilize the coating liquid. Thereafter, wind at 50 ° C. was blown and dried to obtain inkjet recording material 1. The dry coating amount of the ink receiving layer coating liquid 1 is 25 g / m ² .

<Production of vapor phase silica dispersion>
After preparing 4 parts of diallyldimethylammonium chloride homopolymer (molecular weight 9000) and 100 parts of vapor phase process silica (average primary particle size 7 nm, specific surface area 300 m ² / g by BET method) in water, A gas phase method silica dispersion having a solid content concentration of 20% was prepared by a homogenizer treatment. The average secondary particle diameter of the vapor phase method silica was 135 nm.

<Ink-receiving layer coating solution 1>
Gas phase method silica dispersion (as solid phase of gas phase method silica) 100 parts Boric acid 4 parts Polyvinyl alcohol 23 parts (saponification degree 88%, average polymerization degree 3500)
Basic polyaluminum hydroxide 2 parts Zirconium acetate 2 parts Sodium acetate 1.5 parts Solid content concentration of coating solution 12.5%

<Production of inkjet recording material production method 1-1>
The obtained inkjet recording material 1 was subjected to an aging treatment at 40 ° C. under a pressure of 30 hPa or less for 15 hours to obtain an inkjet recording material.

<Preparation of inkjet recording material production method 1-2>
The inkjet recording material 1 obtained above was subjected to an aging treatment at 40 ° C. under a pressure of 200 hPa for 32 hours to obtain an inkjet recording material.

<Preparation of Inkjet Recording Material Production Method 1-3>
The inkjet recording material 1 obtained above was subjected to an aging treatment at 40 ° C. under a pressure of 600 hPa for 72 hours to obtain an inkjet recording material.

<Production of Production Method 1-4 of Comparative Example>
The inkjet recording material 1 obtained above was subjected to an aging treatment at 40 ° C. for 72 hours at normal pressure to obtain an inkjet recording material.

<Production of Production Method 1-5 of Comparative Example>
The inkjet recording material 1 obtained above was stored for 72 hours at 23 ° C. under normal pressure to obtain an inkjet recording material.

  The following evaluation was performed on each recording material obtained as described above. The results are shown in Table 1.

<Evaluation of ink absorbency>
Canon PIXUS iP-4300 manufactured by Canon Co., Ltd. printed a pattern in which fine C lines were embedded in a solid patch of M + Y (red). Immediately after printing, the bleed at the boundary between the fine line and the solid part was as follows. The visual judgment was made according to the criteria.
A: The boundary is very clear and the ink is absorbed quickly. O: The boundary is slightly blurred. No problem in practical use Δ: The boundary is disturbed. There is a problem in practical use ×: The boundary is very disturbed

<Evaluation of bleeding resistance under high humidity>
Inkjet printer PIXUS iP-4300 is a pattern in which fine non-printed parts are combined in a grid pattern on solid patches of each color of C, M, Y, K, M + Y (red), C + Y (green), and C + M (blue) After printing and drying at room temperature for 24 hours, 30 ° C. 80% R.D. H. 10 days, and compared with an image not subjected to the processing on the left, the degree of bleeding and the state of cracking were visually determined according to the following criteria.
○: No blurring or cracking ×: Blotting in solid outlines, thin line-shaped non-printing parts, or cracks observed XX: Blotting solid areas, severe blurring in thin-line non-printing parts, or Cracks are observed

  As is apparent from Table 1, according to the present invention, when printing is performed with a water-based ink jet printer, the void-type ink jet receiving layer has a print quality excellent in ink absorptivity and anti-bleeding property under high humidity. It is possible to obtain the inkjet recording material having a short time.

(Example 2)
After coating the ink receiving layer coating liquid 2 having the following composition on a polystyrene shrink film (film thickness: 60 μm) support with a bar coater so that the solid content coating amount is 15 g / m ² , 20 ° C. wind is blown. And dried to obtain an intermediate process product. Next, the top coat layer coating solution 2 having the following composition was coated on the intermediate process product obtained on the left so that the solid content coating amount was 1 g / m ^2, and then dried by blowing air at 18 ° C. Inkjet recording material 2 was obtained.

<Ink-receiving layer coating solution 2>
Pateracol EG-4X 100 parts spherical silica matting agent (average particle size 20 μm) 0.4 parts ethyl alcohol 5% with respect to coating liquid mass
It adjusted with water so that solid content concentration might be 12%.

<Topcoat layer coating solution 2>
Boric acid 100 parts ethyl alcohol 10% of coating liquid mass
The solid content was adjusted to 5% with water.

<Preparation of inkjet recording material manufacturing method 2-1>
The obtained inkjet recording material 2 was subjected to an aging treatment at 18 ° C. for 120 hours under an atmospheric pressure of 30 hPa or less to obtain an inkjet recording material of Production Method 2-1.

<Preparation of inkjet recording material manufacturing method 2-2>
The inkjet recording material 2 obtained above was subjected to an aging treatment at 18 ° C. under a pressure of 200 hPa for 360 hours to obtain an inkjet recording material of production method 2-2.

<Production of Production Method 2-3 of Comparative Example>
The ink jet recording material 2 obtained above was allowed to stand at normal pressure at 18 ° C. for 360 hours to obtain an ink jet recording material of Production method 2-3 of Comparative Example.

<Production of Production Method 2-4 of Comparative Example>
The ink jet recording material 2 obtained above was subjected to a heat treatment at 40 ° C. for 72 hours at normal pressure. However, a sample capable of withstanding printing evaluation could not be obtained due to thermal shrinkage.

  The obtained recording material was printed and evaluated by a water-based pigment ink printer MAXART PX-W8000 manufactured by Seiko Epson Corporation. In the evaluation, first, an ICC profile of the inkjet recording material of Production Method 2-1 obtained using RIP manufactured by EFI was created. The printing environment is 20 ° C 50% R.D. H. Met.

<Evaluation of ink absorbency>
Using the ICC profile for the ink jet recording material obtained in the production method 2-1 obtained above, in a mode in which a white ink is printed immediately after drawing an image with colored ink called “white to color” Output solid images of C, M, Y, Bk, R, G, B, C + W (white ink), M + W, Y + W, Bk + W, R + W, G + W, B + W, W only, and visually check whether ink is overflowing And evaluated according to the following criteria. The printing environment is 20 ° C 50% R.D. H. Met.
◎: No ink overflow ○: Slight mottling is observed at R + W, G + W, B + W, but there is no practical problem △: Mottling is clearly seen at R + W, G + W, B + W ×: Colored ink + white Mottling is seen in the ink part and ink absorbency is not good

<Evaluation of water resistance>
C, M, Y, Bk, R, G, B, C + W (white ink), M + W, Y + W, Bk + W, R + W, G + W, B + W, W only in the printing order “white to color” using the above ICC profile Characters were output in each of the colors, and the output recording material was then dried for 24 hours. The printing and drying environment after printing was 20 ° C 50% R.D. H. Met. One drop (approximately 50 μl) of water was dropped on the printing part. Then 20 ° C. 50% R.D. H. After being dried for 24 hours, the image and the coating layer were visually judged on the basis of the following criteria.
◎: No disturbance ○: Slightly disturbed but no problem in practical use △: Disturbed, practical problem ×: Significant disorder

<Evaluation of crack resistance under high humidity>
C, M, Y, Bk, R, G, B, C + W (white ink), M + W, Y + W, Bk + W, R + W, G + W, B + W, W only in the printing order “white to color” using the above ICC profile A solid patch of each color was output, and then the output recording material was dried for 24 hours. The printing and drying environment after printing was 20 ° C 50% R.D. H. Met. Thereafter, 15 ° C. 85% R.D. H. 10 days, and compared with an image not subjected to the processing on the left, the degree of bleeding and the state of cracking were visually determined according to the following criteria.
○: No smearing or cracking ×: Smearing or cracking is observed in the outline of the printed part XX: Smearing or cracking is observed in the contouring of the printed part

  As is apparent from Table 2, according to the present invention, when printing is performed with a water-based ink jet printer, the ink absorption property and the water resistance of the image area are excellent even in the swollen ink jet receiving layer, and at high humidity. An ink jet recording material having excellent print quality without cracking of the image area even during storage can be obtained in a short time. In addition, since the method for producing an ink jet recording material of the present invention exhibits an effect even at low temperatures, it is suitable for use in applications such as output calibration of flexible packaging materials.

Claims (4)

  In a method for producing an ink jet recording material comprising an ink-receiving layer containing at least one hydrophilic polymer and a crosslinking agent on a non-water-absorbing support, the air pressure is 800 hPa after the ink-receiving layer is applied and dried. A method for producing an ink jet recording material, comprising performing an aging treatment under the following reduced pressure environment.   The method for producing an ink jet recording material according to claim 1, wherein the non-water-absorbing support is a shrink film, and the aging treatment is performed under a condition of 25 ° C or lower.   2. The method for producing an ink jet recording material according to claim 1, wherein the ink receiving layer mainly contains inorganic fine particles.   The ink receiving layer contains a cationic polyurethane resin, polyvinyl alcohol and boric acid or a salt thereof (however, when the ink receiving layer contains inorganic fine particles, the content of the inorganic fine particles is the total solid content of the ink receiving layer). The method for producing an ink jet recording material according to claim 1, wherein the content is 5% by mass or less.