JP2007245426A - Inkjet recording material for pigment ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording material for a pigment ink which enables attainment of an image having a high printing density, excelling in mar resistance and having a matte tone, depth and stability. <P>SOLUTION: The inkjet recording material for the pigment ink has at least two ink accepting layers on a substrate. The uppermost ink accepting layer (A) provided at the most separated position from the substrate contains wet silica having an average secondary particle diameter of 1.5-2.5 μm, and the ink accepting layer (B) provided between the uppermost ink accepting layer (A) and the substrate mainly contains inorganic particulates having an average secondary particle diameter of 500 nm or less and contains a compound having two or more primary amino groups in a molecule and a resin binder having a keto group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording material, and more particularly, to an ink jet recording material for pigment ink that has a high printing density, excellent scratch resistance, and can provide a matte tone and deep image.

  As a recording material used in the ink jet recording method, a recording material in which an ink receiving layer is provided on a support such as paper or a plastic resin film is known. The ink receiving layer is roughly classified into two types. One type is an ink receiving layer mainly composed of a water-soluble polymer, and the other type is a porous ink receiving layer mainly composed of an inorganic pigment and a resin binder.

  The former type of ink receiving layer absorbs ink by swelling the water-soluble polymer. The latter type of ink receiving layer absorbs ink in voids formed by inorganic pigments. Due to such a difference in ink absorption mechanism, the former type is called a swelling type (or polymer type), and the latter type is called a void type.

  In recent years, a photographic image having an image quality comparable to a silver salt photograph can be printed by an ink jet recording method, and an ink jet recording material having photo-like gloss and texture has been demanded. For such applications, the former polymer type ink-receiving layer is excellent in gloss because it forms a continuous uniform film, but has poor ink absorbability (ink absorption speed; drying speed after printing), while the latter This void type is preferable because of its excellent ink absorbability and high print density. As the latter void type, it has been proposed to use inorganic fine particles such as gas phase method silica or wet method silica pulverized and dispersed to a particle diameter of 500 nm or less as a pigment component of the ink receiving layer. For example, JP-A-3-56552, JP-A-10-119423, JP-A-2000-2111235, and JP-A-2000-309157 disclose examples of using vapor phase silica. JP-A-9-286165, JP-A-10 No. 181190 discloses a use example of pulverized sedimentation silica, and Japanese Patent Application Laid-Open No. 2001-277712 discloses a use example of crushed gel method silica.

  When printing is performed using a dye ink on a recording material using such inorganic fine particles, the ink penetrates and is absorbed into fine voids in the coating layer, and the solvent component including water in the ink volatilizes. The dye will remain in the voids. As a result, the dye is exposed to air and degradation occurs at a very fast rate. Accordingly, there is a problem that the image storability of the void-type recording material using inorganic fine particles is lower than that of the former swelling type recording material.

  In order to solve the problem of image storability, it is known to use a pigment ink having high fastness as a colorant. However, the pigment ink is superior in image storability compared to the water-soluble dye ink in which the colorant is present as a single molecule, but the printing density is insufficient, and the ink particles do not enter the ink receiving layer. In order to form a film on the surface, there is a problem in the scratch resistance of the printed image, and a solution has been desired. Recently, an ink jet recording material for pigment ink using inorganic fine particles which has improved this problem has also been proposed. For example, it is disclosed in JP 2001-96907, JP 2003-251915, JP 2005-7641, JP 2005-53099, and the like.

  In addition, in order to obtain desired characteristics, a technique for applying a plurality of ink receiving layers having different characteristics on a support is known. For example, it has a specific peak in the hole distribution curve of the uppermost layer and the entire ink-receiving layer as described in JP-A No. 58-110287 (Patent Document 1) as a recording material with less ink absorbability and less ink bleeding. Recording materials are known. In addition, zinc oxide having a specific particle size and non-surface area in the uppermost layer as described in JP-A-2001-088438 (Patent Document 2) as a recording material having light resistance and high glossiness of a recorded image; Recording materials having cerium oxide are known.

  Furthermore, as a recording material excellent in ink absorbability, film cracking, and gloss, a recording material using wet method silica in the uppermost ink receiving layer as described in JP-A-2004-237704 (Patent Document 3). As described in JP-A-2004-299164 (Patent Document 4), the upper ink-receiving layer has a wet method silica having an average particle diameter of 500 nm or less and a crack or glare using vapor phase method silica in the lower layer. A recording material for backlit which suppresses sticking is known. However, when printing is performed on these recording materials using pigment ink, the printing density is low, the surface gloss is high, and there is a glare, and there is a problem in the fixability of the pigment ink.

  On the other hand, as described above, since a photographic image having an image quality comparable to a silver salt photograph can be printed by the ink jet recording method, an ink jet recording material having photo-like gloss and texture has been demanded. In general, a recording material having high glossiness is desired. However, a recording material capable of obtaining a matted tone and a deep and calm image is desired depending on the user's preference and the like. In order to obtain such a recording material, it is necessary to suppress glossiness, specifically, an inkjet recording material having a 75 ° glossiness of a blank paper portion of 10.0 or less and a high print density. Japanese Patent Application Laid-Open No. 2005-145043 (Patent Document 5) describes that at least one ink receiving layer contains an inorganic fine particle having an average secondary particle diameter of 500 nm or less, a resin binder having a keto group, and a crosslinking agent thereof. Although a characteristic ink jet recording material is described, it has not been satisfactory because of its high surface gloss.

In order to solve the above problems, a recording material mainly composed of an inorganic pigment, a so-called mat paper, has been used on a conventionally known paper support. When printing is performed using a pigment ink, the pigment ink is applied to the porous layer. Since the ink is submerged and held, the print density is low, and the uniformity of the printed image is insufficient. In order to solve this problem, Japanese Patent Application Laid-Open No. 2005-053136 (Patent Document 6) discloses alumina or hydrated alumina on the upper layer of an ink image receiving layer using an inorganic pigment having an average secondary particle diameter of 1 to 10 μm on a paper support. Inkjet recording materials that use materials are disclosed, but they are not fully satisfactory.
JP 58-110287 A (pages 2 to 5) JP 2001-88438 A (pages 2 to 3) JP 2004-237704 A (pages 2 to 4) JP 2004-299164 A JP 2005-145043 A JP 2005-53136 A

  An object of the present invention is to provide an ink jet recording material having a matte tone and a deep and calm image having a high printing density, excellent color developability, and good scratch resistance when printed with pigment ink.

The above object of the present invention has been achieved by the following ink jet recording material.
(1) The uppermost ink-receiving layer (A) having at least two ink-receiving layers on the support and provided at the position farthest from the support has an average secondary particle size of 1.5-2. The ink-receiving layer (B) containing 5 μm wet process silica and provided between the uppermost ink-receiving layer (A) and the support is mainly composed of inorganic fine particles having an average secondary particle diameter of 500 nm or less. An ink jet recording material for pigment ink, comprising: a compound containing two or more primary amino groups in a molecule; and a resin binder having a keto group.
(2) The inkjet recording material for pigment ink as described in (1) above, wherein the inorganic fine particles mainly contained in the ink receiving layer (B) are vapor-phase process silica.
(3) The inkjet recording material for pigment ink as described in (1) or (2) above, wherein the wet method silica of the uppermost ink receiving layer (A) is gel method silica.
(4) The inkjet recording material for pigment ink according to any one of the above 1 to 3, wherein the surface glossiness (JIS Z-8741; measured at 75 °) is 10.0 or less.

According to the ink jet recording material of the present invention, it is possible to obtain a calm image having a high printing density, excellent scratch resistance, matte tone and depth in the pigment ink.

Hereinafter, the present invention will be described in detail.
The support used in the present invention is a water-absorbing support such as fine paper, art paper, coated paper, cast coated paper, polyester resin such as polyethylene terephthalate and polyethylene naphthalate, diacetate resin, triacetate resin, nitrocellulose Water-resistant supports such as cellulose ester resins such as cellulose acetate, polyolefin resins, acrylic resins, polycarbonate resins, polyvinyl chloride, polyimide resins, polysulfone, polyphenylene oxide, cellophane, celluloid and other plastic resin films, polyolefin resin-coated paper, etc. Etc. are used. Among them, a water-resistant support is preferably used, and among the water-resistant supports, a polyolefin resin-coated paper in which at least one surface of a base paper is coated with a polyolefin resin is particularly preferably used. As the pulp constituting the base paper, natural pulp, recycled pulp, synthetic pulp or the like is used alone or in combination of two or more. This base paper may be blended with additives such as sizing agent, paper strength enhancing agent, filler, antistatic agent, fluorescent brightening agent, dye and the like generally used in papermaking. Alternatively, a surface sizing agent, a surface paper strength agent, a fluorescent brightening agent, an antistatic agent, a dye, an anchor agent, or the like may be applied on the surface.

In addition, the thickness of the base paper is not particularly limited, but preferably has a good surface smoothness such as a paper that is compressed by applying a pressure during or after paper making using a calendar or the like, and has a basis weight of 30 to 250 g / m ² is preferred. However, the density of the base paper is 1.10 g / cm ³ or less, preferably 0.6 to 1.05 g / cm ³ for rigidity. If the density is too small, it is difficult to obtain uniform surface smoothness even if resin coating is performed.

Examples of polyolefin resins include low-density polyethylene, high-density polyethylene, polypropylene, polybutene, olefin homopolymers such as polypentene, or copolymers composed of two or more olefins such as ethylene-propylene copolymer, and mixtures thereof. Those having various densities and melt viscosity indices (melt index) can be used alone or in combination.

  In polyolefin resin, white pigments such as titanium oxide, zinc oxide, talc and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, etc. Fatty acid metal salts, antioxidants such as Irganox 1010 and Irganox 1076, blue pigments and dyes such as cobalt blue, ultramarine blue, cecilian blue and phthalocyanine blue, magenta pigments such as cobalt violet, fast violet and manganese purple It is preferable to add various additives such as dyes, fluorescent brighteners and ultraviolet absorbers in appropriate combinations.

  The polyolefin resin-coated paper used in the present invention is produced by a so-called extrusion coating method in which a heated and melted resin is cast on a traveling base paper, and the surface or both sides thereof are coated with the resin. Moreover, it is preferable to subject the base paper to an activation treatment such as corona discharge treatment or flame treatment before coating the resin on the base paper. The surface (front surface) of the polyolefin resin-coated paper on which the ink receiving layer is applied is processed into a glossy surface, a matte surface, or the like according to the application. It is not necessary to coat the back surface with a resin, but it is preferable to coat the resin from the viewpoint of curling prevention. The back surface is usually a matte surface, and an active treatment such as corona discharge treatment or flame treatment can be applied to the front surface or both the front and back surfaces as necessary. Further, the thickness of the polyolefin resin-coated paper is not particularly limited, but is generally coated on the surface or both sides of the surface to a thickness of 5 to 50 μm on one side.

Next, the ink receiving layer (B) provided between the uppermost ink receiving layer (A) and the support of the present invention will be described.
The inorganic fine particles mainly contained in the ink receiving layer (B) of the present invention are inorganic fine particles having an average secondary particle diameter of 500 nm or less. Here, “mainly containing inorganic fine particles” means that the inorganic fine particles are contained in an amount of 50% by mass or more, more preferably 60% by mass or more, particularly preferably based on the total solid content in the ink receiving layer (B). Is 65% by mass or more, and the upper limit is about 95% by mass. The average secondary particle size referred to in the present invention can be obtained by measuring the diluted dispersion with a laser diffraction / scattering particle size distribution analyzer. The inorganic fine particles mainly used in the ink receiving layer (B) provided between the uppermost ink receiving layer (A) and the support of the present invention are synthetic amorphous silica, alumina, alumina hydrate, carbonic acid. Various known fine particles such as calcium and magnesium carbonate are exemplified, but synthetic amorphous silica and alumina hydrate are preferably used. Synthetic amorphous silica includes a gas phase method, a wet method, and others. In the present invention, gas phase method silica is particularly preferable. Vapor phase silica is also called a dry method and is generally made by flame hydrolysis. 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 silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state. Vapor phase silica is commercially available from Nippon Aerosil Co., Ltd. as Aerosil and Tokuyama Co., Ltd. as QS type.

The average particle diameter of primary particles of vapor-phase process silica that is particularly preferably used in the ink receiving layer (B) of the present invention is preferably 5 to 30 nm, and more preferably 15 nm or less. More preferably, the primary particles have an average particle diameter of 5 to 15 nm and a specific surface area of 200 m ² / g or more by the BET method. The BET method referred to in the present invention is one of powder surface area measurement methods by vapor phase adsorption, and is a method for determining the total surface area, that is, the specific surface area of a 1 g sample from the adsorption isotherm. 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 formula, called the BET formula, 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 primary particle diameter described here is obtained as the particle diameter of a circle, which is equal to the projected area of each of 100 particles existing within a certain area by electron microscope observation of the dispersed particles.

  Wet process silica is further classified into precipitation process silica and gel process 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 silica secondary particles produced by this method become gently 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 Co., Ltd., as a Toku Seal from Tokuyama Co., Ltd., and as a fine seal. Gel silica produces silicate sol by reacting sodium silicate and sulfuric acid under acidic conditions. The silicate sol gradually polymerizes to form primary particles, and further, a three-dimensional aggregate is formed and gelled. This silica is pulverized and pulverized by a general method such as airflow pulverization. That is, in the gel method, reaction polymerization is carried out on the acidic side, left standing until it becomes a gel, washed with water and dried to obtain gel method silica. For example, it is commercially available from Tosoh Silica Co., Ltd. as nip gel and from Mizusawa Chemical Industry Co., Ltd. as Mizukasil.

  In the ink receiving layer (B), vapor-phase method silica and wet method silica are used in the presence of a cationic compound, and the average secondary particle diameter of the silica is 500 nm or less, preferably 10 to 300 nm, more preferably 20 to 200 nm. Dispersed in can be used. As a dispersion method, gas phase method silica and a dispersion medium are premixed by ordinary propeller stirring, turbine type stirring, homomixer type stirring, etc., and then a media mill such as a ball mill, a bead mill, a sand grinder, a high pressure homogenizer, an ultrahigh pressure, etc. It is preferable to perform dispersion using a pressure disperser such as a homogenizer, an ultrasonic disperser, a thin film swirl disperser, or the like.

  As the cationic compound used for the dispersion of the gas phase method silica and the wet method silica, a cationic polymer or a water-soluble metal compound can be used. Examples of the cationic polymer include polyethyleneimine, polydiallylamine, polyallylamine, alkylamine polymer, JP-A-59-20696, JP-A-59-33176, JP-A-59-33177, JP-A-59-155088. JP, 60-11389, JP 60-49990, JP 60-83882, JP 60-109894, JP 62-198493, JP 63-49478, 1 described in JP-A-63-115780, JP-A-63-280681, JP-A-1-40371, JP-A-6-234268, JP-A-7-125411, JP-A-10-193976, etc. A polymer having a tertiary amino group or a quaternary ammonium 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.

  Examples of the water-soluble metal compound include water-soluble polyvalent metal salts, and among them, a compound made of aluminum or a group 4A metal (for example, zirconium or titanium) in the periodic table is preferable. Particularly preferred is a water-soluble aluminum compound. As a water-soluble aluminum compound, for example, as an inorganic salt, aluminum chloride or a hydrate thereof, aluminum sulfate or a hydrate thereof, ammonium alum and the like are known. Furthermore, a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer is known and preferably used.

The basic polyaluminum hydroxide compound has a main component represented by the following general formula 1, 2, or 3, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ _{, [Al 13 (OH) 34} ] 5+, with _{[Al 21 (OH) 60]} 3+, basic water-soluble that contain polynuclear condensed ions of a polymer stable at of polyaluminum hydroxide as an equal is there.

[Al ₂ (OH) _n Cl _6-n ] _m General formula 1
[Al (OH) ₃ ] _n AlCl ₃ general formula 2
Al _n (OH) _m Cl _(3n-m) 0 <m <3n General formula 3

  These are water treatment agents from Taki Chemical Co., Ltd. under the name of polyaluminum chloride (PAC), from Asada Chemical Co., Ltd. under the name of polyaluminum hydroxide (Paho), and from Riken Green Co., Ltd. It is marketed under the name of Purachem WT and from other manufacturers for the same purpose, and various grades can be easily obtained.

  As the water-soluble compound containing a Group 4A element of the periodic table used in the present invention, a water-soluble compound containing titanium or zirconium is more preferable. Examples of the water-soluble compound containing titanium include titanium chloride and titanium sulfate. Water-soluble compounds containing zirconium include zirconium acetate, zirconium chloride, zirconium oxychloride, hydroxy zirconium chloride, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium lactate, zirconium carbonate / ammonium, zirconium carbonate / potassium, zirconium sulfate. And zirconium fluoride compounds. In the present invention, the term “water-soluble” means that 1% by mass or more dissolves in water at room temperature and normal pressure.

  As the alumina 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. γ-alumina can make primary particles as small as about 10 nm. Usually, secondary particles of thousands to tens of thousands of nanometers are averaged by ultrasonic, high-pressure homogenizer, counter collision type jet crusher, etc. What grind | pulverized the particle diameter to 500 nm or less, Preferably about 20-300 nm can be used.

The alumina hydrate of the present invention is represented by a constitutive formula of Al ₂ O ₃ .nH ₂ O (n = 1 to 3). The case where n is 1 represents an alumina hydrate having a boehmite structure, and the case where n is greater than 1 and less than 3 represents an alumina hydrate having a pseudo boehmite structure. It can be obtained by a known production method such as hydrolysis of an aluminum alkoxide such as aluminum isopropoxide, neutralization of an aluminum salt with an alkali, or hydrolysis of an aluminate. The average secondary particle diameter of the alumina hydrate used in the present invention is 500 nm or less, preferably 20 to 300 nm. The method for obtaining the average secondary particle size in alumina and alumina hydrate is synonymous with the method for obtaining the average secondary particle size described above.

  The above-mentioned alumina and alumina hydrate used in the present invention are used in the form of a dispersion dispersed by a known dispersant such as acetic acid, lactic acid, formic acid, nitric acid and the like.

  Two or more kinds of inorganic fine particles may be used in combination from the inorganic fine particles described above. For example, combined use of finely divided wet method silica and vapor phase method silica, combined use of finely divided wet method silica and alumina or alumina hydrate, and combined use of vapor phase method silica and alumina or alumina hydrate. It is done. As for the ratio in the case of this combined use, the range of 7: 3 to 3: 7 is preferable in any embodiment.

In the present invention, the inorganic fine particles are preferably contained in an amount of 8 g / m ² or more, and more preferably in the range of 10 to 40 g / m ² . If it is less than this range, the ink absorbability is inferior.

  In the present invention, the ink receiving layer (B) contains, in addition to the inorganic fine particles, a compound having two or more primary amino groups in the molecule and a resin binder having a keto group.

  An embodiment containing a compound having two or more primary amino groups in the molecule and a resin binder having a keto group will be described. As a first embodiment, for example, a resin binder having a keto group in the ink receiving layer (B) and a compound having two or more primary amino groups in the molecule are contained in advance, or the resin binder is contained immediately before coating. Among them, it is preferable to contain them immediately before coating from the viewpoint of the stability of the coating solution over time. In a second embodiment, the ink receiving layer (B) contains only a resin binder having a keto group, and at least one layer adjacent to the ink receiving layer (B) (for example, in the case of a two-layer structure, the uppermost layer). In the ink receiving layer (A)), a compound having two or more primary amino groups in the molecule is contained, and simultaneous multi-layer coating using a slide bead method or the like described later is used. In a third embodiment, a layer containing a compound having two or more primary amino groups in the molecule is previously applied and dried as a subbing layer or a new layer on the subbing layer. There is a so-called sequential multilayer coating method in which the ink receiving layer (B) containing a resin binder having a group and the uppermost ink receiving layer (A) are coated, and the resin binder is crosslinked.

  The resin binder having a keto group in the present invention can be synthesized by a method of copolymerizing a monomer having a keto group and another monomer. Specific examples of the monomer having a keto group include acrolein, diacetone acrylamide, diacetone methacrylate, acetoacetoxyethyl methacrylate, 4-vinylacetoacetanilide, acetoacetylallylamide, and the like. Further, a keto group may be introduced by a polymer reaction. For example, an acetoacetyl group can be introduced by a reaction between a hydroxy group and a diketene. Specific examples of the resin binder having a keto group include acetoacetyl-modified polyvinyl alcohol, acetoacetyl-modified cellulose derivatives, acetoacetyl-modified starch, diacetone acrylamide-modified polyvinyl alcohol, and resin binders described in JP-A-10-157283. Can be mentioned. In the present invention, modified polyvinyl alcohol having a keto group is particularly preferable. Examples of the modified polyvinyl alcohol having a keto group include acetoacetyl-modified polyvinyl alcohol and diacetone acrylamide-modified polyvinyl alcohol.

  The acetoacetyl-modified polyvinyl alcohol can be produced by a known method such as a reaction between polyvinyl alcohol and diketene. The degree of acetoacetylation is preferably from 0.1 to 20 mol%, more preferably from 1 to 15 mol%. The saponification degree is preferably 80 mol% or more, more preferably 85 mol% or more. As a polymerization degree, the thing of 500-5000 is preferable, and the thing of 1000-4500 is especially preferable.

  Diacetone acrylamide-modified polyvinyl alcohol can be produced by a known method such as saponification of a diacetone acrylamide-vinyl acetate copolymer. As content of a diacetone acrylamide unit, the range of 0.1-15 mol% is preferable, and also the range of 0.5-10 mol% is preferable. The saponification degree is preferably 85 mol% or more, and the polymerization degree is preferably 500 to 5,000.

  In the present invention, in addition to the resin binder having a keto group, another known resin binder may be used in combination as long as the effect of the resin binder having a keto group is not hindered. For example, cellulose derivatives such as carboxymethyl cellulose and hydroxypropyl cellulose, starch and various modified starches, gelatin and various modified gelatins, chitosan, carrageenan, casein, soy protein, polyvinyl alcohol and various modified polyvinyl alcohols such as cationic modified polyvinyl alcohol, Polyvinyl pyrrolidone, polyacrylamide, etc. can be used together as necessary. Furthermore, various latexes may be used in combination as the binder resin.

  The smaller the total content of these resin binders, the smaller the void volume in the ink receiving layer and the better the ink absorbability.However, if the amount is too small, the ink receiving layer becomes brittle and surface defects such as cracks increase. Therefore, the range of 5 to 40% by mass is preferable with respect to the inorganic fine particles, and 10 to 30% by mass is particularly preferable.

  Next, a compound containing two or more primary amino groups of the present invention in the molecule will be described. The primary amino group of the present invention includes an aliphatic group, an aromatic group, a primary amino group bonded to a carbon atom of a heterocyclic group, and a primary amino group bonded to a nitrogen atom (that is, a terminal amino group of hydrazine). From the viewpoint of the thickening effect after mixing, a hydrazine-type amino group is preferable, and a hydrazide, semicarbazide, or carbohydrazide structure is particularly preferable. Specific examples of the compound having two or more primary amino groups bonded to carbon atoms include ethylenediamine, diethylenetriamine, triethylenediamine, metaxylenediamine, norbornanediamine, 1,3-bisaminomethylcyclohexane, and the like. Specific examples of the compound having two or more amino groups include hydrazine and salts thereof, carbohydrazide, succinic acid dihydrazide, adipic acid dihydrazide, citric acid trihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, and the like, Examples include a reaction product of polyisocyanate and hydrazine such as 4,4′-ethylene disemicarbazide and 4,4′-hexamethylene disemicarbazide, and a polymer hydrazide such as polyacrylic acid hydrazide. In particular, succinic acid dihydrazide and adipic acid dihydrazide are preferable in terms of water solubility and reactivity.

  Although there is no particular limitation on the content of the compound containing two or more primary amino groups in the molecule of the present invention, in terms of productivity and the characteristics of the ink receiving layer obtained, with respect to the resin binder having a keto group, The range of 0.1-50 mass%, and also 1-20 mass% is preferable.

  In the ink-receiving layer (B) in the present invention, known cationic polymers, preservatives, surfactants, coloring dyes, colored pigments, ultraviolet absorbers, antioxidants, and pigment dispersions together with the resin binder having the keto group. An agent, an antifoaming agent, a leveling agent, a fluorescent brightening agent, a viscosity stabilizer, a pH adjusting agent and the like can also be added.

Next, the uppermost ink receiving layer (A) will be described.
The uppermost ink-receiving layer (A) of the present invention contains wet-process silica having an average secondary particle size of 1.5 to 2.5 μm. When the average secondary particle diameter is less than 1.5 μm or exceeds 2.5 μm, the density when printing with pigment ink is lowered. The oil absorption of the wet process silica in the present invention is preferably in the range of 200 to 350 ml / 100 g. The oil absorption is measured based on the description of JIS K-5101. If the oil absorption is less than 200 ml / 100 g or more than 350 ml / 100 g, the scratch resistance is deteriorated. As described above, the wet method silica is classified into the precipitation method silica and the gel method silica. In the present invention, the gel method silica is particularly preferable because it has high absorptivity and improves the color developability of the pigment ink. The average secondary particle size measured in the present invention can be measured by a commercially available particle size distribution measuring device, for example, a particle size distribution measuring device such as LA-920 manufactured by Horiba, Ltd., LS230 manufactured by Beckman Coulter, or the like.

  As the wet process silica used in the ink receiving layer (A) of the present invention, a pulverized and dispersed fine particle or a pulverized granular material can be used. The atomized powder is commercially available from Mizusawa Chemical Co., Ltd. as Mizukasil and Tosoh Silica Co., Ltd. as a nip gel. In addition, the granular material with rough pulverization is generally expressed as silica gel and is used as a desiccant, a chromatographic filler, and the like. These granular materials are commercially available as QP type from Toyoda Chemical Co., Ltd. and Fuji Silica Gel from Fuji Silysia Science Co., Ltd.

  The wet process silica can be further finely pulverized for use. As a pulverization method, a wet dispersion method in which silica dispersed in an aqueous medium is mechanically pulverized can be preferably used. As the wet disperser, 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, a thin film winding disperser, and the like can be used.

  The wet process silica having an average secondary particle size of 1.5 μm to 2.5 μm used in the ink receiving layer (A) of the present invention is 50% by mass with respect to the total solid content in the uppermost ink receiving layer (A). Contains above. More preferably, it is 60 mass% or more, Most preferably, it is 65 mass% or more, and an upper limit is about 95 mass%.

  In the present invention, the wet process silica used for the ink receiving layer (A) is usually dispersed in an aqueous medium, but a dispersant may be added if necessary. A usable dispersing agent is preferably one that adsorbs to the surface of the silica particles and functions to stabilize the dispersion, and examples thereof include a cationic compound. The cationic compound is the same as described above. A dispersing agent may be used independently and may use 2 or more types together.

  As the resin binder used in the ink-receiving layer (A), various known binders can be used, and a hydrophilic binder that is highly transparent and provides higher ink permeability is preferably used. When using a hydrophilic binder, it is important that the hydrophilic binder does not swell during initial penetration of the ink to prevent voids. From this viewpoint, a hydrophilic binder having a relatively low swellability around room temperature is preferable. Used. Particularly preferred hydrophilic binders are fully or partially saponified polyvinyl alcohol or cation-modified polyvinyl alcohol. Particularly preferred among polyvinyl alcohols are those having a degree of saponification of 80% or more or those having been completely saponified. Those having an average degree of polymerization of 200 to 5000 are preferred. The amount used is 10 to 30% by mass with respect to wet-process silica having an average secondary particle size of 1.5 to 2.5 μm.

  In the second embodiment described above, the ink receiving layer (A) in the present invention contains a compound containing two or more primary amino groups in the molecule together with the resin binder, but other embodiments. Various crosslinking agents (hardeners) can also be used in Specific examples of the crosslinking agent include aldehyde compounds such as formaldehyde, glutaraldehyde, glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, bis (2-chloroethylurea), 2-hydroxy-4,6-dichloro. -1,3,5-triazine, compounds having reactive olefins as described in US Pat. No. 3,635,718, isocyanates as described in US Pat. No. 3,103,437, There are halogen carboxaldehydes as described in Patent Nos. 3,017,280 and 2,983,611, dioxane derivatives such as dihydroxyoxane, chromium alum, inorganic crosslinking agents such as zirconium sulfate, etc. Species or a combination of two or more can be used. The usage-amount is 0.02-50 mass% with respect to polyvinyl alcohol, and 0.5-35 mass% is especially preferable.

  Similarly to the ink receiving layer (B), the ink receiving layer (A) is a cationic polymer, an antiseptic, a surfactant, a coloring dye, a coloring pigment, an ultraviolet absorber, an antioxidant, a pigment dispersant, an anti-foaming agent. Foaming agents, leveling agents, fluorescent whitening agents, viscosity stabilizers, pH adjusting agents and the like can also be added.

In the present invention, dry coating weight in the range of the uppermost layer of the ink receiving layer (A) is preferably from 0.5~18g / m ^2, more preferably in the range of ^{1~10g / m 2, 1~5g / m} 2 The range of is particularly preferable. The above range is preferable in terms of color developability and bleeding after printing.

  The glossiness of the recording material of the present invention, that is, the 75 ° specular glossiness defined by JIS-P-8741 of the surface of the uppermost ink-receiving layer (A) is preferably 10% or less. Usually, if the glossiness is kept low, the print density tends to be low. However, by adopting the configuration of the ink receiving layer (B) and the uppermost layer of the present invention, a high print density can be satisfied with a low glossiness. it can. As a result, a calm image having a matte tone and depth can be obtained.

  In the present invention, a known coating method can be used as a coating method of each layer constituting the ink receiving layer. For example, there are a slide bead method, a curtain method, an extrusion method, an air knife method, a roll coating method, and a kedverting method.

  When the ink receiving layer coating solution is applied to the support, corona discharge treatment, fire treatment, ultraviolet irradiation treatment, plasma treatment or the like is preferably performed prior to coating.

  In the present invention, it is preferable to provide an undercoat layer mainly composed of a natural polymer compound or a synthetic resin on the surface of the support on which the ink receiving layer is provided. The ink receiving layer containing the inorganic fine particles of the present invention is applied on the undercoat layer, and then cooled and dried at a relatively low temperature, whereby the transparency of the ink receiving layer is further improved.

  The undercoat layer provided on the support is mainly composed of natural polymer compounds such as gelatin and casein and synthetic resins. Examples of such synthetic resins include acrylic resins, polyester resins, vinylidene chloride, vinyl chloride resins, vinyl acetate resins, polystyrene, polyamide resins, polyurethane resins, and the like. Further, in the third embodiment described above, a compound containing two or more primary amino groups in the molecule can be contained, but in other embodiments, various crosslinking agents (hardeners). Can be used.

  The undercoat layer is provided on the support with a film thickness (dry film thickness) of 0.01 to 5 μm. Preferably it is the range of 0.05-5 micrometers.

  In the third embodiment described above, a layer containing a compound containing a compound containing two or more primary amino groups in the molecule is provided between the undercoat layer and the ink receiving layer (B). Can be provided. The layer can appropriately contain a known resin binder, a surfactant and the like. Moreover, as application | coating thickness, it is provided by the film thickness (dry film thickness) of 0.1-20 micrometers on an undercoat layer, Preferably it is the range of 0.5-10 micrometers.

  Various back coat layers can be coated on the support in the present invention for antistatic properties, transport properties, anticurling properties, and the like. The back coat layer may contain an appropriate combination of inorganic antistatic agent, organic antistatic agent, resin binder, latex, pigment, curing agent, surfactant and the like.

  The pigment ink used for printing on the recording material of the present invention is preferably an aqueous pigment ink, in which conventionally known organic and inorganic pigments are dispersed in water together with various auxiliary agents such as a dispersant and a surfactant. Conventionally known organic and inorganic pigments include, for example, azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, Polycyclic pigments such as isoindolinone pigments and quinophthalone pigments, dye lakes such as basic dye type lakes and acid dye type lakes, organic pigments such as nitro pigments, nitroso pigments, aniline black and daylight fluorescent pigments, contacts And inorganic pigments such as carbon black produced by a method such as a method, a furnace method, or a thermal method.

  Preferred examples of yellow pigments include Dinichi First Yellow G (trade name, CI Pigment Yellow 1 manufactured by Dainichi Seika Kogyo Co., Ltd.), and Dinichi First Yellow GR (trade name, Dainichi Seika Kogyo). CI Pigment Yellow 2), Daiichi First Yellow 10G (trade name, manufactured by Dainichi Seika Co., Ltd., CI Pigment Yellow 3), Monolite First Yellow 5G (trade name, Imperial Chemical) CI Pigment Yellow 4) manufactured by Industries, Sanyo First Yellow 5G (trade name, manufactured by Sanyo Dye Co., Ltd., CI Pigment Yellow 5), Daiichi First Yellow 3G (trade name, Dainichi Seika Co., Ltd.) CI Pigment Yellow 6), Sanyo First Yellow R (trade name, manufactured by Sanyo Dye Co., Ltd.) CI Pigment Yellow 10), Sanyo Benzidine Yellow B (trade name, manufactured by Sanyo Pigment Co., Ltd., CI Pigment Yellow 12), Sanyo Light First Benzidine Yellow R (trade name, manufactured by Sanyo Pigment Co., Ltd.) CI Pigment Yellow 13), Sumitomo Yellow G (trade name, manufactured by Sumitomo Chemical Co., Ltd., CI Pigment Yellow 14), 2600 benzidine yellow (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd., Pigment) Yellow 15), Simula First Yellow 8GR (trade name, manufactured by Dainippon Ink & Chemicals, Inc., CI Pigment Yellow 17), Chromophthal Yellow 8GN (trade name, manufactured by Ciba Geigy, CI Pigment Yellow) 128), chromophthal yellow 6G (trade name, manufactured by Ciba Geigy, CI Pigment Ye -94), chromoftal yellow 3G (trade name, manufactured by Ciba-Geigy, CI Pigment Yellow 93), chromoftal yellow GR (trade name, manufactured by Ciba-Geigy, CI Pigment Yellow 95), Kayaset Yellow E -AR (trade name, manufactured by Nippon Kayaku Co., Ltd., CI Pigment Yellow 147), Chromophthal Yellow 2RLTS (trade name, manufactured by Ciba Geigy, CI Pigment Yellow 110), Irgazine Yellow 2GLTE (Product) Name, Ciba-Geigy, CI Pigment Yellow 109), Irgadine Yellow 2RLT (trade name, Ciba-Geigy, CI Pigment Yellow 110), Irgazine Yellow RRLTN (Product name, Ciba-Geigy, CI Pigment) Yellow 110), Irgarite Yellow F4G (Product) Name, Ciba Geigy, C.I. I. Pigment Yellow 111), Irgarite Yellow BRM (trade name, manufactured by Ciba Geigy, CI Pigment Yellow 14), Micro Lease Yellow 3G-WA (trade name, manufactured by Ciba Geigy, CI Pigment Yellow 13), Micro Lease Yellow 2R-WA (trade name, manufactured by Ciba Geigy, CI Pigment Yellow 83).

  Examples of red pigments include Sanyo Signal Red (trade name, manufactured by Sanyo Dye Co., Ltd., CI Pigment Red 1), and Dinichi Permanent Red 4R (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd.). Pigment Red 3), Dinichi Permanent Red RX (trade name, manufactured by Daiichi Seika Kogyo Co., Ltd., CI Pigment Red 4), Sumitomo Carmine B (trade name, manufactured by Sumitomo Chemical Co., Ltd., CI Pigment Red 5), Sanyo First Red (trade name, manufactured by Sanyo Pigment Co., Ltd., CI Pigment Red 6), Sanyo Permanent Red G-207 (trade name, manufactured by Sanyo Pigment Co., Ltd., CI Pigment) Red 9), Bordeaux F-2R (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd., CI Pigment Red 12), Sanyo First Red GR (trade name, Sanyoiro) CI Pigment Red 21), Sumitomo Scarlet FSH (trade name, manufactured by Sumitomo Chemical Co., Ltd., CI Pigment Red 22), Sanyo First Red 10B (trade name, Sanyo Dye Co., Ltd.) CI Pigment Red 23), Microly Thread RBS-WA (trade name, manufactured by Ciba Geigy, CI Pigment Red 23), Dainichi # 930 First Red (trade name, Daiichi Seika Kogyo Co., Ltd.) CI Pigment Red 38), 950 Red (trade name, manufactured by Daiichi Seika Kogyo Co., Ltd., CI Pigment Red 41), Dinichi Permanent Red (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd.) CI Pigment Red 48 (Calcium Reiki)), Sanyo First Red 2B (trade name, manufactured by Sanyo Dye Co., Ltd., CI Pigment) Tread 48 (Barium Reiki)), Sanyo Pigment Scarlet TR (trade name, manufactured by Sanyo Dye Co., Ltd., CI Pigment Red 48 (Strontium Reiki)), Sumitomo Red 2BM (trade name, manufactured by Sumitomo Chemical Co., Ltd.) CI Pigment Red 48 (Manganese Reiki)), Simula Reiki Red R (trade name, manufactured by Dainippon Ink & Chemicals, Inc., CI Pigment Red 49 (Barium Reiki)), Simula Reiki Red D (trade name, manufactured by Dainippon Ink & Chemicals, Inc., CI Pigment Red 50), Simula Reiki Red C (trade name, manufactured by Dainippon Ink & Chemicals, Inc., CI Pigment Red 53) (Barium Reiki)), Sumitone Red 6F (trade name, manufactured by Sumitomo Chemical Co., Ltd., CI Pigment Red 57) (Calcium Reiki)), Simula First Bordeaux 10B (trade name, manufactured by Dainippon Ink & Chemicals, Inc., C.I. I. Pigment Red 63 (Barium Reiki)), Dainichi First Pink GX, G Toner (trade name, Dainichi Seika Kogyo Co., Ltd., CI Pigment Red 81), Sumitone Red GS (trade name, Sumitomo Chemical Co., Ltd.) CI Pigment Red 112), Simula First Carmine BS (trade name, manufactured by Dainippon Ink and Chemicals, CI Pigment Red 114), Chromophthal Scarlet RN (trade name, Ciba Geigy) CI Pigment Red 166), Chromotal Red G (trade name, manufactured by Ciba Geigy, CI Pigment Red 220), Chromotal DPP Red BP (trade name, manufactured by Ciba Geigy, CI Pigment Red 254) ), Chromoftal red BRN (trade name, manufactured by Ciba Geigy, CI Pigme Tread 144), chromoftal red A2B (trade name, manufactured by Ciba-Geigy, CI Pigment Red 177), Shinkasia Red BNRT742D (trade name, manufactured by Ciba-Geigy, CI Pigment Violet 19), Shinkasia Red BRT790- D (trade name, manufactured by Ciba Geigy, CI Pigment Violet 19), Micro Lease Scarlet R-WA (trade name, manufactured by Ciba Geigy, CI Pigment Red 166), Micro Lease 2B-WA (trade name, manufactured by Ciba Geigy) CI Pigment Red 221), Micro Lease Magenta B-WA (trade name, manufactured by Ciba Geigy, CI Pigment Red 184).

  Blue pigments include Simex Blue BOF (trade name, manufactured by Dainippon Ink & Chemicals, Inc., CI Pigment Blue 1), Simurex Blue 16F (trade name, manufactured by Dainippon Ink & Chemicals, Inc.) CI Pigment Blue 2), Fast Gen Blue B, BS (trade name, manufactured by Dainippon Ink & Chemicals, Inc., CI Pigment Blue 15), Fast Gen Blue GS, 2G (trade name, Dai Nippon) Ink Chemical Industry Co., Ltd., CI Pigment Blue 15), Fast Gen Sky Blue (trade name, manufactured by Dainippon Ink and Chemicals, CI Pigment Blue 17), Sumitone Navy Blue (Product) Name, manufactured by Sumitomo Chemical Co., Ltd., CI Pigment Blue 25), Chromophthal Blue A3R (trade name, manufactured by Ciba Geigy, CI Pigment) Blue 60), Chromophthal Blue 4GNP (trade name, manufactured by Ciba Geigy, CI Pigment Blue 15: 3), Iilgalite Blue FR (trade name, manufactured by Ciba Geigy, CI Pigment Blue 62), Micro Lease Blue 4G-WA (trade name, manufactured by Ciba Geigy, CI Pigment Blue 15: 3).

  Examples of black pigments include Sanyo Diamond Black (trade name, manufactured by Sanyo Dye Co., Ltd., CI Pigment Black 1), and Micro Lease Black C-WA (trade name, manufactured by Ciba Geigy, CI Pigment Black 7 ( Carbon black)), MA7 (trade name, manufactured by Mitsubishi Chemical Industries, Inc., CI Pigment Black 7 (carbon black)), RAVEN 780, 1080 (trade name, manufactured by Columbia Carbon, CI Pigment Black 7 ( And carbon black))).

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In the examples and comparative examples, “parts” and “%” indicate parts by mass and mass% unless otherwise specified. In addition, the number of parts shown in the blend is the number of substantial components.

(Production of support)
A 1: 1 mixture of hardwood kraft pulp (LBKP) and softwood sulfite pulp (NBSP) was beaten to 300 ml with Canadian Standard Freeness to prepare a pulp slurry. As a sizing agent, 0.5% by mass of alkyl ketene dimer with respect to pulp, 1.0% by mass of polyacrylamide with respect to pulp as a strengthening agent, 2.0% by mass of cationized starch with respect to pulp, and polyamide epichlorohydrin resin 0.5% by mass of pulp was added and diluted with water to give a 1% 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 base paper for the support. A polyethylene resin composition in which 10% by mass of anatase-type titanium is uniformly dispersed with respect to 100% by weight of low density polyethylene having a density of 0.918 g / cm ³ is melted at 320 ° C. at 320 ° C. The film was extracted and coated so as to have a thickness of 35 μm per minute, and extrusion coated using a cooling roll having a finely roughened surface. On the other side, a blend resin composition of 30 parts by mass of a low density polyethylene resin having a density of 0.918 g / cm ³ is similarly melted at 320 ° C., extrusion coated to a thickness of 30 μm, and roughened. Extrusion coating was performed using a cooling roll.

After subjecting the surface of the support to high-frequency corona discharge treatment, an undercoat layer having the following composition was prepared by coating and drying so that the gelatin was 50 mg / m ² .
(Underlayer)
Lime-processed gelatin: 100 parts, Sulfosuccinic acid-2-ethylhexyl ester salt: 2 parts, Chrome alum: 10 parts

(Ink receiving layer (B))
4 parts of dimethylallyl ammonium chloride homopolymer (molecular weight 9,000) and 100 parts of gas phase method silica (average primary particle diameter 7 nm) are added to ion-exchanged water, and a sawtooth blade type disperser (blade peripheral speed 20 m / second) is added. And passed through a pressure homogenizer once under the condition of 40 MPa to obtain a silica dispersion having a solid content concentration of 20% by mass and an average secondary particle size of 150 nm.

  Using 103 parts of the above dispersion, 23 parts of an acetoacetyl-modified polyvinyl alcohol solution (solid content concentration 8%, manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd .: GOHSEIMER Z410) was mixed with a 3% denatured ethanol aqueous solution. A coating solution for the ink receiving layer (B) was prepared. The solid content concentration of the coating solution at this time was 12%.

(The uppermost ink receiving layer (A))
(Dispersion adjustment)
Commercially available wet method silica (manufactured by Tosoh Silica Co., Ltd., trade name: NIPGEL AY-200, average secondary particle size 2.3 μm, BET specific surface area 300 m ² / g, pore volume 1.6 ml / g, oil absorption 280 ml / 100 g, gel method silica) was continuously dispersed together with ion-exchanged water to which 10% NaOH had been added in advance using a disperser (manufactured by Tokushu Kika Kogyo Co., Ltd., TK Robotics). T.A. K. Robomix was used at 3000 rpm. Thereafter, AGESTAT A50 (Ciba Specialty Chemicals Water Treatment, Inc. USA, polyethylene polyamine / dimethylamine / epichlorohydrin polycondensate, hereinafter referred to as AGA50) was added to 5 parts with respect to 100 parts of silica, and It was made to disperse | distribute at 3000 rpm with said disperser. The solid content concentration of silica in the dispersion was 13%.

(Adjustment of uppermost ink receiving layer (A) coating solution)
100 parts of the above dispersion, 23 parts of a polyvinyl alcohol solution (solid concentration 8%, manufactured by Kuraray Co., Ltd .: PVA235, saponification degree 88%, polymerization degree 3500), adipic acid dihydrazide 19 parts, fluorine-based surfactant (Sey Chemical Co., Ltd. product: Surflon S-131) 0.3 part was mixed with 3% denatured ethanol aqueous solution to prepare a coating solution. The pH of the coating solution at this time was adjusted to 4.1. The coating solution concentration was 11%.

(Preparation of recording material)
The ink-receiving layer to the support of the undercoat layer is coated (B) an ink receiving layer coating solution and the uppermost layer (A) coating liquid, so as respectively to ^{22g / m 2, 3g / m} 2 The recording material of Example 1 was prepared by simultaneously applying with a slide bead coating apparatus and drying.

  Except for changing the acetoacetyl-modified polyvinyl alcohol of the ink receiving layer (B) coating liquid in Example 1 to diacetone acrylamide-modified polyvinyl alcohol (diacetone acrylamide modification degree 5 mol%, saponification degree 98 mol%, polymerization degree 1700). The recording material of Example 2 was produced in the same manner as Example 1.

  A recording material of Example 3 was prepared in the same manner as in Example 1 except that the adipic acid dihydrazide in the coating liquid for the uppermost ink-receiving layer (A) in Example 1 was changed to succinic acid dihydrazide. At this time, the pH of the uppermost ink-receiving layer (A) coating solution was adjusted to 4.1.

Instead of AY-200 of the uppermost ink-receiving layer (A) dispersion in Example 1, Mizkasil P-803 (manufactured by Mizusawa Chemical Industry Co., Ltd., average secondary particle diameter 2.4 μm, BET specific surface area 180 m) ² / g, pore volume 0.6 ml / g, oil absorption 210 ml / 100 g, precipitated silica) was used in the same manner as in Example 1 to produce a recording material of Example 4. At this time, the pH of the uppermost ink-receiving layer (A) coating solution was adjusted to 4.1.

100 parts of a polyvinyl alcohol solution (solid concentration 8%, manufactured by Kuraray Co., Ltd .: PVA205, saponification degree 88%, polymerization degree 500) on the support on which the undercoat layer of Example 1 was applied, adipic acid 70 parts of dihydrazide was mixed with a 3% denatured ethanol aqueous solution, and the coating solution was applied with a slide bead coating device so as to be 1.0 g / m 2 and dried. Thereafter, the ink receiving layer (B) coating solution of Example 1 and the uppermost ink receiving layer (A) coating solution of Example 1 to which adipic acid dihydrazide was not added were respectively 22 g / m ² and 3 g / m. The recording material of Example 5 was produced by applying simultaneously with a slide bead coating device so as to be ² , and drying. At this time, the coating solution pH of the uppermost ink receiving layer (A) was adjusted to 4.1.

  Example 1 except that adipic acid dihydrazide in the uppermost ink-receiving layer (A) coating solution in Example 1 was not added, but 2.3 parts of adipic acid dihydrazide was added in-line to the ink-receiving layer (B) immediately before coating. In the same manner as described above, the recording material of Example 6 was produced. At this time, the pH of the uppermost ink-receiving layer (A) coating solution was adjusted to 4.1.

Instead of vapor phase method silica used in the ink receiving layer (B) of Example 1, wet method silica (manufactured by Tosoh Silica Co., Ltd., NIPGEL AZ-200, average secondary particle size 2.4 μm, BET ratio) Example 1 except that a coating solution for the ink receiving layer (B) was prepared as follows using a surface area of 300 m ² / g, a pore volume of 2.0 ml / g, an oil absorption of 330 ml / 100 g, and a gel method silica). Similarly, a recording material of Example 7 was produced.

(Primary dispersion process of dispersion of gel method silica)
Industrial water having an electric conductivity of 150 mS / cm is set to a flow rate of 5.0 L / min by using a cartridge pure water production apparatus (manufactured by Organo Corporation, model G-5), and the electric conductivity is 9.0 μS / min. cm water was prepared. Next, 7.0 kg of the water was weighed, and 3.0 kg of gel method silica (NIPGEL AZ-200, manufactured by Tosoh Silica Co., Ltd.) was added, and a disperser (Special Machine Industries Co., Ltd., Hibiss) was added. Disperse mix 3D-10 type) was used for dispersion for 60 minutes at a disperser peripheral speed of 21.0 m / sec and a planetary rotation speed of 30 rpm to obtain a 30 mass% gel silica dispersion.

(Secondary dispersion step of dispersion of gel method silica)
The gel method silica dispersion obtained in the primary dispersion step was subjected to a bead filling rate of 70% by volume (using 0.3 mmΦ zirconia beads) with a bead mill (Shinmaru Enterprises Co., Dynomill), a disk peripheral speed of 12.5 m / second, Two-pass processing was performed under the condition of a pump flow rate of 300 ml / min. The average secondary particle diameter of this dispersion was measured with a particle size distribution meter (LA-920, manufactured by Horiba, Ltd.), and the result was 200 nm.

(Adjustment of ink receiving layer (B) coating solution)
Using 100 parts of the above dispersion, 23 parts of an acetoacetyl-modified polyvinyl alcohol solution (solid content concentration 8%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: Gohsephimer Z410) was mixed with 3% denatured ethanol aqueous solution. A coating solution for the ink receiving layer (B) was prepared. The solid content concentration of the coating solution at this time was 12%.

  In place of the wet method silica used in the uppermost ink-receiving layer (A) of Example 1, wet method silica (manufactured by Tosoh Silica Co., Ltd., NIPGEL AZ-200, gel method silica) was used. Thus, a recording paper of Example 8 was produced in the same manner as in Example 1 except that the coating liquid for the uppermost ink-receiving layer (A) was produced.

(Primary dispersion process of dispersion of gel method silica)
Using industrial water with an electrical conductivity of 150 mS / cm and a cartridge pure water production apparatus (Gorgan-5, Model G-5), the flow rate is set to 5.0 L / min and the electrical conductivity is 9.0 μS / cm. Water was prepared. Next, 7.0 kg of the water was weighed, and 3.0 kg of gel method silica (manufactured by Tosoh Silica Co., Ltd., NIPGEL AZ-200) was added, and a disperser (made by Tokushu Kika Kogyo Co., Ltd., Hibis Dispermix 3D-10 type) ) Was used for dispersion for 60 minutes at a disperser peripheral speed of 21.0 m / sec and a planetary rotation speed of 30 rpm to obtain a 30 mass% gel method silica dispersion.

(Secondary dispersion step of dispersion of gel method silica)
The gel method silica dispersion obtained in the primary dispersion step was subjected to a beads filling rate of 50% by volume (using 0.3 mmΦ zirconia beads) with a bead mill (Shinmaru Enterprises Co., Ltd., Dynomill), a disk peripheral speed of 12.5 m / second, One-pass processing was performed under the condition of a pump flow rate of 300 ml / min. The average secondary particle size was measured by a particle size distribution meter (LA-920, manufactured by Horiba, Ltd.), and the result was 1.8 μm.

(Adjustment of uppermost ink receiving layer (A) coating solution)
100 parts of the dispersion, 23 parts of a polyvinyl alcohol solution (8%, manufactured by Kuraray Co., Ltd .: PVA235), 19 parts of adipic acid dihydrazide, a fluorosurfactant (manufactured by Seimi Chemical Co., Ltd .: Surflon S-131) Three parts were mixed with 3% denatured ethanol aqueous solution to prepare a coating solution. The pH of the coating solution at this time was adjusted to 4.1. The coating solution concentration was 11%.

(Comparative Example 1)
The acetoacetyl-modified polyvinyl alcohol of the ink receiving layer (B) of Example 1 was changed to 23 parts of unmodified polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: PVA235, saponification degree 88%, polymerization degree 3500), and boric acid 4 A recording material of Comparative Example 1 was produced in the same manner as in Example 1 except that parts were added.

(Comparative Example 2)
The recording material of Comparative Example 2 was produced in the same manner as in Example 1 except that the adipic acid dihydrazide in the uppermost ink-receiving layer (A) of Example 1 was omitted, but significant cracking occurred on the coated surface. did. At this time, the coating solution pH of the uppermost ink receiving layer (A) was adjusted to 4.1.

(Comparative Example 3)
The recording material of Comparative Example 3 was prepared in the same manner as in Example 1 except that the adipic acid dihydrazide in the uppermost ink-receiving layer (A) of Example 1 was changed to propionic acid hydrazide. Significant cracks occurred. At this time, the coating solution pH of the uppermost ink receiving layer (A) was adjusted to 4.1.

(Comparative Example 4)
Instead of the wet method silica used in the uppermost ink-receiving layer (A) of Example 1, wet method silica (manufactured by Tosoh Silica Co., Ltd., NIPGEL AZ-200, gel method silica) was used as follows. A recording paper of Comparative Example 4 was prepared in the same manner as in Example 1 except that the coating liquid for the uppermost ink receiving layer (A) was prepared.

(Primary dispersion process of dispersion of gel method silica)
Using industrial water with an electrical conductivity of 150 mS / cm and a cartridge pure water production apparatus (Gorgan-5, Model G-5), the flow rate is set to 5.0 L / min and the electrical conductivity is 9.0 μS / cm. Water was prepared. Next, 7.0 kg of the water was weighed, and 3.0 kg of gel method silica (manufactured by Tosoh Silica Co., Ltd., NIPGEL AZ-200) was added, and a disperser (made by Tokushu Kika Kogyo Co., Ltd., Hibis Dispermix 3D-10 type) ) Was used for dispersion for 60 minutes at a disperser peripheral speed of 21.0 m / sec and a planetary rotation speed of 30 rpm to obtain a 30 mass% gel method silica dispersion.

(Secondary dispersion step of dispersion of gel method silica)
The gel method silica dispersion obtained in the primary dispersion step was subjected to a beads filling rate of 60% by volume (using 0.3 mmΦ zirconia beads) with a bead mill (Shinmaru Enterprises Co., Ltd., Dynomill), a disk peripheral speed of 12.5 m / second, One-pass processing was performed under the condition of a pump flow rate of 300 ml / min. The average secondary particle diameter was measured with a particle size distribution meter (LA-920, manufactured by Horiba, Ltd.), and the result was 1.4 μm.

(Adjustment of uppermost ink receiving layer (A) coating solution)
100 parts of the dispersion, 23 parts of a polyvinyl alcohol solution (8%, manufactured by Kuraray Co., Ltd .: PVA235), 19 parts of adipic acid dihydrazide, a fluorosurfactant (manufactured by Seimi Chemical Co., Ltd .: Surflon S-131) Three parts were mixed with 3% denatured ethanol aqueous solution to prepare a coating solution. The pH of the coating solution at this time was adjusted to 4.1. The coating solution concentration was 11%.

(Comparative Example 5)
In place of AY-200 of the uppermost ink-receiving layer (A) dispersion in Example 1, NIPGEL CY-200 (manufactured by Tosoh Silica Corporation, average secondary particle size: 2.7 μm, BET specific surface area: 800 m ² / G, pore volume 1.1 ml / g, oil absorption 185 ml / 100 g, gel method silica) was used in the same manner as in Example 1 to produce a recording material of Comparative Example 5. At this time, the pH of the uppermost ink-receiving layer (A) coating solution was adjusted to 4.1.

(Comparative Example 6)
A recording material was prepared in the same manner except that the one-pass treatment was performed under the same conditions in the secondary dispersion step of the gel silica dispersion of the ink receiving layer (B) of Example 7. The average secondary particle diameter was measured with a particle size distribution meter (LA-920, manufactured by Horiba, Ltd.), and the result was 750 nm.

(Comparative Example 7)
A recording material of Comparative Example 7 was produced in the same manner as in Example 6 except that the uppermost ink receiving layer (A) of Example 6 was not applied.

The following items were evaluated for the obtained recording materials. The results are shown in Table 1.
《Glossiness》
Using a variable angle photometer (VGS-1001DP) manufactured by Nippon Denshoku Industries Co., Ltd., the 75 ° gloss was measured and evaluated according to the following criteria.
○: A mat. (10.0 or less)
Δ: Slightly glossy but sufficiently matte. (10.0 to 20.0)
X: Glossy and matte texture cannot be obtained. (20.0 or more)

<< Evaluation of image 1 >>
A monochrome landscape image is printed with an ink jet printer (Seiko-Epson Corporation, PX-5500; using water-based pigment ink), and whether or not a matte and deep, calm image is obtained visually is shown below. Evaluated by criteria. Δ or more satisfies a matte tone and deep calm image.
◯: A calm image with a matte tone and high print density and depth is obtained.
Δ: Slightly inferior in the depth of the image, but has a sufficiently matte texture.
X: Glossy and matte texture cannot be obtained, or the print density is low and the image depth is inferior.

<< Image Evaluation 2 >>
The following criteria are used to visually determine whether a color human image is printed with an ink jet printer (Seiko Epson Corporation, PX-5500; water-based pigment ink used) and a matte and deep, calm image is obtained. It was evaluated with.
◯: A calm image with a matte tone and high print density and depth is obtained.
Δ: Slightly inferior in the depth of the image, but has a sufficiently matte texture.
X: Glossy and matte texture cannot be obtained, or the print density is low and the image depth is inferior.

<Print density>
After black solid printing was performed on an inkjet printer (Seiko Epson Corporation, PX-5500; using aqueous pigment ink), the optical density (OD value) was measured using an optical densitometer (manufactured by Kimoto Co., Ltd., Gretag Macbeth AG SpectroEye). No. 16228). The higher the value, the higher the print density and the better.

《Scratch resistance》
Using an inkjet printer for pigment ink (PX-G900 manufactured by Seiko Epson Corporation), solid printing was continuously performed with a maximum ink discharge amount of Blue, and the image portion through which the giza roll passed was visually evaluated.
○: No peeling of pigment ink.
Δ: Slight peeling of pigment ink.
X: There is peeling of the pigment ink.

From the above results, it can be seen that according to the present invention, an ink jet recording material for pigment ink can be obtained which has a high printing density, excellent scratch resistance, and can provide a matte tone and deep image. Further, when the inorganic fine particles mainly contained in the ink receiving layer (B) are gas phase method silica, and when the wet method silica of the uppermost ink receiving layer (A) is gel method silica, the effect is further improved. It turns out to be high.
On the other hand, since the recording material of Comparative Example 1 did not contain a resin binder having a keto group in the ink receiving layer (B), the print density and image evaluation were slightly lower than those of the Examples. Further, since the recording materials of Comparative Examples 2 and 3 did not contain a compound having two or more primary amino groups in the molecule, significant cracking occurred. Further, since the recording materials of Comparative Examples 4 and 5 contained the wet method silica outside the range of the average secondary particle diameter of 1.5 to 2.5 μm in the uppermost ink receiving layer (A), compared with the Examples. Print density and image evaluation were slightly low. In addition, since the recording material of Comparative Example 6 contained inorganic fine particles having an average secondary particle size exceeding 500 nm in the ink receiving layer (B), the print density and image evaluation were slightly lower than those of the Examples. Further, since the recording material of Comparative Example 7 was not provided with the uppermost ink receiving layer (A), the printing density was high, but there was no matte texture and the image evaluation and scratch resistance were inferior.

Claims (4)

  The ink receiving layer (A), which is the uppermost layer provided at the position farthest from the support and has at least two ink receiving layers on the support, is a wet type having an average secondary particle diameter of 1.5 to 2.5 μm. The ink receiving layer (B) provided between the uppermost ink receiving layer (A) and the support mainly contains inorganic fine particles having an average secondary particle diameter of 500 nm or less, An ink jet recording material for pigment ink, comprising a compound having two or more primary amino groups in a molecule and a resin binder having a keto group.   2. The ink jet recording material for pigment ink according to claim 1, wherein the inorganic fine particles mainly contained in the ink receiving layer (B) are vapor phase silica.   The inkjet recording material for pigment ink according to claim 1 or 2, wherein the wet method silica of the uppermost ink receiving layer (A) is gel method silica.   The inkjet recording material for pigment ink according to any one of claims 1 to 3, wherein the surface glossiness (JIS Z-8741; 75 ° measurement) is 10.0 or less.