JP4190427B2 - Inkjet recording material and method for producing the same - Google Patents

Description

  The present invention relates to an ink jet recording material, and more specifically, an ink jet recording material having high photo-like gloss without cracks, excellent ink absorbability and water resistance, and high productivity and waste liquid treatment, and its production. Regarding the method.

  As a recording material used in the ink jet recording system, a porous ink receiving layer comprising a pigment such as amorphous silica and a water-soluble binder such as polyvinyl alcohol is provided on a support called an ink jet recording paper. Recording materials are known.

  In recent years, recording materials that use extremely fine inorganic particles as a pigment and have a photo-like gloss have been known. For example, it has been proposed to use inorganic ultrafine particles such as gas phase method silica or wet method silica pulverized and dispersed to 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 the use of vapor phase silica. JP-A-9-286165, JP-A-10-181190 Japanese Laid-Open Patent Publication No. 2001-277712 discloses an example of using pulverized sedimentation silica, and Japanese Laid-Open Patent Publication No. 2001-277712 discloses an example of using crushed gel silica. JP-A-62-174183, JP-A-2-276670, JP-A-5-32037, JP-A-6-199034 and the like disclose recording materials using alumina or alumina hydrate.

  However, when inorganic ultrafine particles are used, high gloss can be obtained, but the viscosity of the coating liquid tends to be high, and since the coating is applied at a low solid content concentration, surface defects such as wind ripples and cracks during drying tend to occur. In particular, when a water-resistant support such as polyolefin resin-coated paper (laminated with polyolefin resin such as polyethylene on both sides of the paper) or polyester film is used to obtain high gloss and good texture, Since the ink cannot be absorbed, the ink absorbability of the ink receiving layer provided on the support is important. Therefore, it is necessary to apply a large amount of pigment with a reduced ratio of the binder to the inorganic fine particles, and defects occur during drying. It was easy.

  In order to prevent such surface defects, a method is known in which a coating liquid containing a crosslinking agent is applied to a support and then dried under relatively mild conditions. For example, in JP-A-10-119423, 2000-27093, 2001-96900, etc., a boron compound such as boric acid, borate, or borax is used as a crosslinking agent for polyvinyl alcohol, and a coating solution is applied. A method is disclosed in which the coating liquid is increased in viscosity by cooling once and then dried at a relatively low temperature. Aldehyde compounds, epoxy compounds, isocyanates, and the like have also been studied, but it is difficult to achieve both crosslinkability and various properties as an inkjet recording material. To date, crosslinking agents that surpass boron compounds The actual situation is not found. However, even when a boron compound is used as a cross-linking agent, the coating film often becomes defective depending on the coating and drying conditions, and coating failures such as cracks and cracks are noticeable at slight drying temperature changes or high drying temperatures. There was a case. In addition, there are disadvantages such as insufficient water resistance of the coating layer. Furthermore, since a long time is required especially in a drying process, there exists a problem that productivity cannot be made high.

  On the other hand, it is known to use a resin having a keto group for an ink jet recording material. For example, JP-A-63-176173, JP-A-10-157283 (Patent Document 1), JP-A-2000-52646, etc. Describes a method of using the polymer swelling type ink receiving layer as a main component. JP-B-4-15746, JP-A-2000-280600, JP-A-2001-72711, JP-A-2001-213045, and JP-A-2003-237226 (Patent Document 2) disclose a binder component of a porous ink receiving layer. The use of acetoacetyl-modified polyvinyl alcohol is described.

However, these prior arts relate to the provision of photo-like high gloss without cracks in ink-jet recording materials using inorganic ultrafine particles, improved ink absorbency, improved water resistance, improved productivity, and waste liquid processability. There is no description.
JP-A-10-157283 (pages 3 to 6) JP 2001-237226 A (pages 2 to 5)

  An object of the present invention relates to an ink jet recording material, and more specifically, an ink jet recording material having high photo-like gloss without cracks, excellent ink absorbability and water resistance, and high productivity and waste liquid treatment. The manufacturing method is provided.

  As a result of intensive studies to solve this problem, the present inventors have completed the present invention by the following means.

(1) In a recording material in which at least one ink receiving layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder is provided on a support, the ink receiving layer has molecules of boron compounds and primary amino groups. It contains a compound having two or more hydrazide groups in the molecule as a compound having two or more in the molecule, and a modified polyvinyl alcohol having a keto group which is a resin binder having a keto group as a resin binder. Inkjet recording material.
(2) As the resin binder, a modified polyvinyl alcohol having a keto group which is a resin binder having a keto group and an unmodified polyvinyl alcohol, a modified polyvinyl alcohol having a keto group which is a resin binder having a keto group, and an unmodified 2. The inkjet recording material as described in 1 above, wherein the polyvinyl alcohol has a mass ratio of 3/7 to 7/3.
(3) In the method for producing an ink jet recording material in which at least one ink receiving layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder is provided on a support, a boron compound and a primary are provided on the support. Coating containing a compound having two or more hydrazide groups in the molecule as a compound having two or more amino groups in the molecule and a modified polyvinyl alcohol having a keto group which is a resin binder having a keto group as a resin binder A method for producing an ink jet recording material, comprising: applying a working solution, gelling the coating solution with cold air of 10 ° C. or lower, and drying at a drying end temperature of 50 ° C. or higher.

  In a recording material in which at least one ink receiving layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder is provided on a support, the ink receiving layer contains 2 boron compounds and primary amino groups in the molecule. Containing a compound having at least one and containing a resin binder having a keto group as a resin binder, and applying a coating solution containing the compound, and gelling the coating solution with cold air of 10 ° C. or less After that, when the drying end temperature is 50 ° C. or higher, the ink-jet recording material has high photo-like gloss without cracks, excellent ink absorbability and water resistance, and high productivity and waste liquid treatment. And a manufacturing method thereof.

  Hereinafter, the present invention will be described in detail. Examples of the inorganic fine particles used in the ink receiving layer of the present invention include various known fine particles such as amorphous synthetic silica, alumina, alumina hydrate, calcium carbonate, magnesium carbonate, and titanium dioxide. Amorphous synthetic silica, alumina, or alumina hydrate is preferred from the viewpoint of properties.

  Amorphous synthetic silica can be roughly classified into wet method silica, gas phase method silica, and others depending on the production method. 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 the steps of filtration, washing, drying, pulverization and classification. Precipitated silica is commercially available, for example, from Nippon Silica Co., Ltd. as a nip seal, and from Tokuyama Co., Ltd. as Toku Seal. Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During aging, the microparticles dissolve and reprecipitate so as to bind the other primary particles, so that the distinct primary particles disappear and form relatively hard aggregated particles having an internal void structure. For example, it is commercially available from Nippon Silica as nip gel and from Grace Japan as syloid and silo jet. The sol method silica is also called colloidal silica, and is obtained by heating and aging a silica sol obtained through metathesis of sodium silicate acid or through an ion exchange resin layer. For example, it is commercially available as Snowtex from Nissan Chemical Industries, Ltd. Yes.

  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 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. and QS type from Tokuyama Co., Ltd.

In the present invention, vapor phase silica is particularly preferably used. The average primary particle diameter of the vapor phase 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 (especially 3 to 10 nm) and a specific surface area by the 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 is an average particle diameter obtained by observing the diameter of a circle equal to the projected area of each of 100 primary particles existing within a certain area by observation of fine particles with an electron microscope. 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 obtaining the total surface area, that is, the specific surface area of a 1 g sample from the adsorption isotherm. 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 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.

  In the ink receiving layer of the present invention, the vapor phase method silica is used in the presence of a cationic compound, and the average secondary particle size of the vapor phase method silica is 500 nm or less, preferably 10 to 300 nm, more preferably 20 to 200 nm. Dispersed ones 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. The average secondary particle diameter as used in the present invention is an average particle diameter of dispersed aggregated particles observed by observing the ink receiving layer of the obtained recording material with an electron microscope. It is.

  In the present invention, wet process silica pulverized to an average secondary particle diameter of 500 nm or less can also be preferably used. The wet process silica particles used in the present invention are preferably wet process silica particles having an average primary particle diameter of 50 nm or less, preferably 3 to 40 nm, and an average aggregate particle diameter of 5 to 50 μm. It is preferable to use wet method silica fine particles finely pulverized to an average secondary particle diameter of 500 nm or less, preferably about 20 to 200 nm in the presence of.

  Since the wet process silica produced by a normal method has an average aggregate particle diameter of 1 μm or more, it is used after being finely pulverized. As a pulverization method, a wet dispersion method in which silica dispersed in an aqueous medium is mechanically pulverized can be preferably used. At this time, the increase in the initial viscosity of the dispersion is suppressed, high concentration dispersion is possible, and the pulverization / dispersion efficiency is increased so that the particles can be further pulverized. It is preferable to use precipitated silica of 5 μm or more. By using a high-concentration dispersion, the productivity of recording paper is also improved. The oil absorption is measured based on the description of JIS K-5101.

  As a specific method for obtaining wet method silica fine particles having an average secondary particle diameter of 500 nm or less of the present invention, first, silica particles and a cationic compound are mixed in water (whichever comes first or at the same time). And each dispersion or aqueous solution may be mixed, and at least one dispersion device such as a sawtooth blade type dispersion device, a propeller blade type dispersion device, or a rotor stator type dispersion device is used. To obtain a preliminary dispersion. If necessary, an appropriate low boiling point solvent may be added. The higher the solid content concentration of the silica pre-dispersion, the higher the concentration. However, since the dispersion becomes impossible when the concentration is too high, the preferred range is 15 to 40% by mass, and more preferably 20 to 35% by mass. Next, by applying a stronger mechanical means, a wet process silica fine particle dispersion having an average secondary particle diameter of 500 nm or less is obtained. As the mechanical means, a known method can be adopted, for example, a media mill such as a ball mill, a bead mill, a sand grinder, a high pressure homogenizer, a pressure disperser such as an ultra high pressure homogenizer, an ultrasonic disperser, and a thin film swirl disperser. Can be used.

  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. As the cationic polymer, polyethyleneimine, polydiallylamine, polyallylamine, alkylamine polymer, JP-A-59-20696, JP-A-59-33176, JP-A-59-33177, JP-A-59-155088, Sho 60-11389, Sho 60-49990, Sho 60-83882, Sho 60-109894, Sho 62-198493, Sho 63-49478, Sho 63-115780, Shosho 63-280681, No. 1-40371, No. 6-234268, No. 7-125411, No. 10-193976, etc. The polymer having 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⁺ , [Al ₂₁ (OH) ₆₀ ] ³⁺ , etc. 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. 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 whose size is pulverized to a particle size of 500 nm or less, preferably about 20 to 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, 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 above-mentioned alumina and alumina hydrate used in the present invention are used in the form of a dispersion dispersed with a known dispersant such as acetic acid, lactic acid, formic acid, nitric acid and the like.

  In the present invention, a resin having a keto group is used as a binder for inorganic fine particles. The resin binder having a keto group 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. 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.

  Examples of the cation-modified polyvinyl alcohol include polyvinyl alcohol having a primary to tertiary amino group or a quaternary ammonium group in the main chain or side chain of polyvinyl alcohol as described in JP-A-61-110483. It is.

  Among them, in the present invention, when a resin binder having a keto group and an unmodified polyvinyl alcohol are used in combination so that the respective mass ratios are 3/7 to 7/3, the resin binder having a keto group will be described later. While maintaining an effective cross-linking action by the reaction of a compound having two or more primary amino groups in the molecule, it is possible to improve waste liquid treatment properties such as fluidity and detergency when the coating liquid after cross-linking is diluted.

  In this case, the unmodified polyvinyl alcohol has a saponification degree of 80% or more, preferably an average polymerization degree of 200 to 5000, and more preferably an average polymerization degree of 2000 to 5000.

  The amount of the resin binder to be used in combination is not particularly limited as long as the effect of the resin binder having a keto group and a compound having two or more primary amino groups in the molecule can be obtained.

  The smaller the total content of the resin binder, the smaller the void volume in the ink receiving layer, which is preferable in terms of increasing the ink absorbency.However, if the amount is too small, the ink receiving layer becomes brittle and surface defects such as cracks increase. Since glossiness falls, the range of 5-40 mass% is preferable with respect to inorganic fine particles, and 10-30 mass% is especially preferable.

  Next, the boron compound of the present invention will be described. As the boron compound of the present invention, an oxygen acid having a boron atom as a central atom and salts thereof are shown. Specifically, orthoboric acid, metaboric acid, hypoboric acid, tetraboric acid, pentaboric acid and salts thereof. It is more preferable to use at least one selected from boric acid or borax.

  Although there is no restriction | limiting in particular about content of the boron compound of this invention, From the surface of productivity and the characteristic of the ink receiving layer obtained, 1-50 mass% with respect to all the resin binders, Preferably it is 5-40 mass%. is there.

  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 present invention, other known hardeners may be used in combination. When modified polyvinyl alcohol is used as the resin binder, the polyvinyl alcohol cross-linking agent (hardener) includes aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, and bis (2-chloroethyl). Urea), 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, US Pat. No. 3,635 , Compounds having reactive olefins as described in US Pat. No. 2,718,316, 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 and 2,983,611. Compounds, carbodiimide compounds as described in US Pat. No. 3,100,704, epoxy compounds as described in US Pat. No. 3,091,537, halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane Inorganic cross-linking agents such as chromium alum and zirconium sulfate can be used in combination.

  In the present invention, in a recording material provided with an ink receiving layer on a support, at least one of the ink receiving layers has inorganic fine particles having an average secondary particle diameter of 500 nm or less, a resin binder having a keto group, a boron compound, and a primary amino acid. A manufacturing method in which a coating solution containing a compound having two or more groups in the molecule is applied, the coating solution is gelled with cold air of 10 ° C. or lower, and then dried at a drying end temperature of 50 ° C. or higher. Is preferably formed.

  In the present invention, gelation refers to a state in which the viscosity of the coating liquid increases and the coating liquid does not flow with the wind blown in the drying process. Preferably, it is in a state that does not substantially exhibit fluidity.

  The drying end point of the present invention is a point where the moisture content of the coating liquid applied to the support is 8% or less, and can be easily measured with a non-contact infrared moisture meter or the like. The temperature at the end of drying in the present invention is the dryer temperature at the end of drying.

  In the present invention, a coating liquid containing a resin binder having a keto group and an unmodified polyvinyl alcohol as the resin binder, and a mass ratio of the resin binder having a keto group to the unmodified polyvinyl alcohol is 3/7 to 7/3. After coating on the support, the coating resin is gelled and immobilized with cold air of 10 ° C. or less by the reaction of all the resin binders and the boron compound, and the drying that has the greatest effect on cracking and cracking of the coating layer is particularly effective. At the end point, by accelerating the reaction of the resin binder having the keto group and the compound having two or more primary amino groups in the molecule at a temperature of 50 ° C. or higher, the ink absorption and An ink jet recording material having excellent water resistance can be obtained. The temperature of the cold air is preferably 0 ° C. or lower, and the temperature at the end of drying is preferably 60 ° C. or higher, more preferably 70 ° C. or higher. Moreover, since it can dry at high temperature, high productivity is obtained compared with the manufacturing method which uses only polyvinyl alcohol and a boric acid, and is made to gel on low temperature, and is dried on comparatively mild conditions.

  In the present invention, as a method of heat drying, a method of passing through high-temperature air, a method of closely contacting a heat roll, a method of using an infrared heating device, a microwave heating device, or the like can be used.

The dry coating amount of the ink receiving layer of the present invention, ink absorbency, strength of the ink receiving layer, and in terms of productivity, the scope of 8~40g / m ² as solid content of the inorganic fine particles, in particular 10 to 30 g / A range of m ² is preferred.

  In the present invention, it is preferable that the ink receiving layer further contains a cationic compound for the purpose of improving the water resistance of the ink dye. Examples of the cationic compound include the cationic polymer and the water-soluble metal compound mentioned in the description of the dispersion of silica. Examples of water-soluble metal compounds include water-soluble salts of metals selected from calcium, barium, manganese, copper, cobalt, nickel, iron, zinc, chromium, magnesium, tungsten, and molybdenum. Specifically, for example, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, chloride chloride Dicopper, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel sulfate Ammonium hexahydrate, nickel amidosulfate tetrahydrate, ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexa Hydrate, zinc sulfate, zinc p-phenolsulfonate, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate Nonahydrate, sodium phosphate, sodium tungsten citrate, 12 tungstophosphoric acid n-hydrate, dodecatungstosilicic acid 26-hydrate, molybdenum chloride, dodecamolybdophosphoric acid n-hydrate. Among these, a cationic polymer having a molecular weight of about 5,000 to 100,000 and a compound made of aluminum or a Group 4A metal (for example, zirconium or titanium) in the periodic table are preferable, and an aluminum compound is particularly preferable. One type of cationic compound may be used, or a plurality of compounds may be used in combination.

  In the present invention, in addition to at least one ink receiving layer, the ink jet recording material may be further provided with a layer having another function such as an ink absorbing layer having a different structure or a protective layer.

  In the present invention, the ink receiving layer of each layer further includes a surfactant, a coloring dye, a coloring pigment, an ink dye fixing agent, an ultraviolet absorber, an antioxidant, a pigment dispersant, an antifoaming agent, a leveling agent, an antiseptic. Various known additives such as an agent, a fluorescent brightening agent, a viscosity stabilizer, and a pH adjuster can also be added.

  Examples of the support used in the present invention include polyethylene, polypropylene, polyvinyl chloride, diacetate resin, triacetate resin, cellophane, acrylic resin, polyethylene terephthalate, polyethylene naphthalate and other water-resistant supports such as polyolefin resin-coated paper, Water-absorbing supports such as high-quality paper, art paper, coated paper, cast coated paper and the like are used. Preferably a non-absorbable support is used. Among non-absorbent supports, polyolefin resin-coated paper is particularly preferable. The thickness of these supports is preferably about 50 to 250 μm.

  In the case of using a support, particularly a film or resin-coated paper which is a non-absorbing support, it is preferable to provide a primer layer mainly composed of a natural polymer compound or a synthetic resin on the surface on which the ink receiving layer is provided. The primer 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. The primer 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 0.01-2 micrometers.

  Various back coat layers can be coated on the support in the present invention for writing properties, antistatic properties, transport properties, anticurling properties and the like. The backcoat layer can contain an appropriate combination of inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, pigments, curing agents, surfactants, and the like.

  When the ink receiving layer coating solution is applied to a film support or resin-coated paper, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, plasma treatment or the like is preferably performed prior to coating.

  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, a rod bar coating method, and the like.

  The coloring material used in the ink used in the ink jet recording material of the present invention may be either a dye or a pigment, and can be dissolved or dispersed in water and a known water-soluble organic solvent. In addition, a surfactant, a dispersant, an inclusion compound, etc. may be added to the ink composition in order to further stabilize the dissolution and dispersion state of the coloring material. An agent, a chelating agent, a preservative, a rust inhibitor, a viscosity modifier, a conductive agent, or the like can be contained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the content of this invention is not restricted to an Example. In addition, a part represents the mass part of solid content or a substantial component.

<Preparation of polyolefin resin-coated paper support>
A 1: 1 mixture of hardwood bleached kraft pulp (LBKP) and softwood bleached sulfite pulp (NBSP) 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% was added and diluted with water to make a 1% slurry. The slurry was papermaking so that the basis weight of 170 g / m ² by Fourdrinier paper machine to obtain a base paper of the polyolefin resin-coated paper dried and subjected to moisture conditioning to prepare. A polyethylene resin composition in which 10 parts of anatase-type titanium is uniformly dispersed is melted at 320 ° C. with respect to a resin of 100 parts of low density polyethylene having a density of 0.918 g / cm ³ , at 320 ° C. Extrusion coating was carried out to a thickness of 35 μm, and extrusion coating was performed using a cooling roll having a finely roughened surface. 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 The film was extrusion-coated to a thickness of 30 μm and extrusion-coated using a cooling roll having a rough surface.

Was subjected to high frequency corona discharge treatment of the polyolefin resin-coated paper surface, a primer layer having the following composition gelatin creates a support by coating and drying so that 50 mg / m ² (about 0.05 .mu.m).

<Primer layer>
Lime-processed gelatin 100 parts Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chrome alum 10 parts

<Recording sheet 1>
After adding 4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of vapor phase silica (average primary particle diameter 7 nm, specific surface area 300 m ² / g) to water to prepare a preliminary dispersion, a high-pressure homogenizer To prepare a silica dispersion 1 having a solid concentration of 20%. The silica dispersion liquid 1 and other chemicals dissolved in water were mixed at 30 ° C. to prepare an ink receiving layer coating liquid 1 having the following composition. The silica particles are coated on the support with a wire bar so that the coating amount of silica particles is 20 g / m ^2. First, 5 ° C. cold air is applied to the coated surface for 30 seconds to gel the coating solution, and then 40 ° C. Then, air at 80 ° C. was sequentially blown and dried. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.
<Ink-receiving layer coating solution 1>
Silica dispersion 1 (as silica solid content) 100 parts acetoacetyl-modified polyvinyl alcohol 22 parts (acetoacetylation degree 3%, saponification degree 98%, average polymerization degree 2500)
Boric acid 4 parts adipic acid dihydrazide 2 parts

<Recording sheet 2>
4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of precipitated silica (oil absorption 200 ml / 100 g, average primary particle size 16 nm, average aggregated particle size 9 μm) are added to water, and a sawtooth blade type A preliminary dispersion was prepared using a disperser (blade peripheral speed 30 m / sec). Next, the obtained preliminary dispersion was treated with a bead mill to obtain a silica dispersion 2 having a solid concentration of 30%. The silica dispersion 2 and other chemicals dissolved in water are mixed at 30 ° C. to prepare an ink-receiving layer coating liquid 2 having the following composition, so that the coating amount of silica particles is 20 g / m ^2. The recording sheet 2 was obtained by coating the support with a wire bar and drying the recording sheet 1 in the same manner. In addition, the average secondary particle diameter of the silica fine particles was 100 nm as observed with an electron microscope, and the temperature at the end of drying of the coating liquid was 80 ° C.
<Ink-receiving layer coating solution 2>
Silica dispersion 2 (as silica solid content) 100 parts acetoacetyl-modified polyvinyl alcohol 16 parts (degree of acetoacetylation 3%, degree of saponification 98%, average degree of polymerization 2500)
Boric acid 3 parts Adipic acid dihydrazide 1.5 parts

<Recording sheet 3>
Nitric acid (2 parts) and pseudo boehmite (average primary particle size 14 nm) were added to water, and an alumina hydrate dispersion with a solid content concentration of 20% was prepared using a sawtooth blade type disperser. This alumina hydrate dispersion and other chemicals dissolved in water were mixed at 30 ° C. to prepare ink receiving layer coating liquid 3 having the following composition, so that the coating amount of alumina hydrate particles was 20 g / m ² . The recording sheet 3 was obtained by coating the support with a wire bar and drying it in the same manner as the recording sheet 1. In addition, the average secondary particle diameter of the alumina hydrate particles was 80 nm from observation with an electron microscope, and the temperature at the end of drying of the coating liquid was 80 ° C.
<Ink-receiving layer coating solution 3>
Alumina hydrate dispersion (as alumina hydrate solid content) 100 parts acetoacetyl-modified polyvinyl alcohol 12 parts (acetoacetylation degree 3%, saponification degree 98%, average polymerization degree 2500)
Boric acid 2 parts Adipic acid dihydrazide 1.2 parts

<Recording sheet 4>
Except for changing the binder component of the ink receiving layer coating liquid 1 to 25 parts of diacetone acrylamide-modified polyvinyl alcohol (diacetone acrylamide modification degree 5 mol%, saponification degree 98 mol%, polymerization degree 1700), the recording sheet 1 and In the same manner, a recording sheet 4 was obtained. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 5>
A recording sheet 5 was obtained in the same manner as the recording sheet 1 except that the adipic acid dihydrazide in the ink receiving layer coating liquid 1 was changed to 1.7 parts of succinic acid dihydrazide. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 6>
The ink receiving layer coating liquid 1 was dried except that the coating liquid was first gelled by applying cold air of 5 ° C. to the coating surface for 30 seconds, and then air of 40 ° C. and 55 ° C. was sequentially blown to dry. A recording sheet 6 was obtained in the same manner as the recording sheet 1. The average secondary particle diameter of the silica fine particles was 80 nm as observed with an electron microscope, and the temperature at the end point of drying of the coating liquid was 55 ° C.

<Recording sheet 7>
The same ink-receiving layer coating liquid as that of the recording sheet 1 was applied onto the support with a wire bar so that the amount of silica particles applied was 20 g / m ² , and then applied to a wind of 15 ° C. for 30 seconds. Next, 80 ° C. wind was blown and dried to obtain a recording sheet 7. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 8>
After applying the same ink-receiving layer coating liquid as that of the recording sheet 1 on the support with a wire bar so that the amount of silica particles applied is 20 g / m ² , first, cool air of 5 ° C. is applied to the coating surface for 30 seconds. The coating liquid was gelled and then dried by blowing air at 40 ° C. to obtain a recording sheet 8. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 40 ° C.

<Recording sheet 9>
The binder component of the ink-receiving layer coating liquid 1 was changed to 13.2 parts and 8.8 parts, respectively, of the same acetoacetyl-modified polyvinyl alcohol and unmodified polyvinyl alcohol (saponification degree 88 mol%, polymerization degree 3500). Recorded sheet 9 in the same manner as recording sheet 1. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 10>
The binder component of the ink-receiving layer coating liquid 1 was changed to 4.4 parts and 17.6 parts, respectively, of the same acetoacetyl-modified polyvinyl alcohol and unmodified polyvinyl alcohol (saponification degree 88 mol%, polymerization degree 3500). Obtained a recording sheet 10 in the same manner as recording sheet 1. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 11>
A recording sheet 11 was obtained in the same manner as the recording sheet 1 except that the ink receiving layer coating liquid 1 did not contain boric acid. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 12>
A recording sheet 12 was obtained in the same manner as the recording sheet 1 except that the adipic acid dihydrazide was removed from the ink receiving layer coating liquid 1. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 13>
A recording sheet 13 was obtained in the same manner as the recording sheet 1 except that the adipic acid dihydrazide in the ink receiving layer coating liquid 1 was changed to 2 parts of propionic acid hydrazide. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 14>
4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of precipitated silica (oil absorption 250 ml / 100 g, average primary particle size 30 nm, average aggregated particle size 2 μm) are added to water, and a sawtooth blade type Silica dispersion 3 was prepared using a disperser (blade peripheral speed 30 m / sec). The silica dispersion 3 and other chemicals dissolved in water are mixed at 30 ° C. to prepare an ink-receiving layer coating liquid 4 having the following composition, and the silica particle coating amount is 20 g / m ^2. The recording sheet 14 was obtained by coating the support with a wire bar and drying in the same manner as the recording sheet 1. The average secondary particle size of the silica fine particles was 1.0 μm as observed by electron microscope, and the temperature at the end of drying of the coating solution was 80 ° C.
<Ink-receiving layer coating solution 4>
Silica dispersion 3 (as silica solid content) 100 parts acetoacetyl-modified polyvinyl alcohol 16 parts (acetoacetylation degree 3%, saponification degree 98%, average polymerization degree 2500)
Boric acid 3 parts Adipic acid dihydrazide 1.5 parts

<Recording sheet 15>
A recording sheet 15 was obtained in the same manner as the recording sheet 1 except that the binder component of the ink receiving layer coating liquid 1 was changed to 22 parts of partially saponified polyvinyl alcohol (saponification degree 88 mol%, polymerization degree 3500). In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 16>
The binder component of the ink-receiving layer coating solution 1 was changed to 22 parts of partially saponified polyvinyl alcohol (saponification degree 88 mol%, polymerization degree 3500), and the same procedure as in recording sheet 1 was performed except that adipic acid dihydrazide was not added. Thus, a recording sheet 16 was obtained. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 80 ° C.

<Recording sheet 17>
The same ink-receiving layer coating liquid as that of the recording sheet 16 was coated on the support with a wire bar so that the amount of silica particles applied was 20 g / m ² , and then cold air of 5 ° C. was applied to the coated surface for 30 seconds. The coating liquid was applied to gel, and then dried by blowing air at 40 ° C. to obtain a recording sheet 17. In addition, the average secondary particle diameter of the silica fine particles was 80 nm from observation with an electron microscope, and the temperature at the end point of drying of the coating liquid was 40 ° C.

  The following evaluation was performed about each obtained inkjet recording sheet. The results are shown in Table 1.

<Evaluation of cracks on the coated surface>
The coated surface of the coated and dried ink receiving layer was observed and evaluated according to the following criteria.
(Double-circle): There is no crack and it is a uniform coated surface.
○: Small cracks that are difficult to distinguish visually are generated, but are very few and no problem.
Δ: Small cracks that are difficult to distinguish visually are generated.
X: A large crack that can be clearly identified visually is generated.

<Glossiness of white paper part>
The glossiness of the blank paper before printing on the recording sheet was observed obliquely and evaluated according to the following criteria.
(Double-circle): There exists a glossiness as high as a color photograph.
○: Not as good as a color photograph, but has a sufficient gloss.
Δ: Slightly glossy.
X: There is no glossiness.

<Ink absorbability>
Red, blue, green, and black solid printing with a commercially available inkjet printer (Epson, PM-950C). Immediately after printing, the amount of ink transferred onto the PPC paper by lightly pressing the PPC paper over the print area. The degree of was observed visually. Evaluation was made according to the following criteria.
○: Not transferred.
Δ: A thin transfer is observed on the entire printed portion.
X: A dark transfer is observed over the entire printed part.

<Water resistance of ink receiving layer>
Water droplets were dropped on the surface of the recording sheet and left for 1 minute, then the surface was rubbed to observe the surface state.
◯: No change Δ: Part of the ink receiving layer is scraped off, resulting in a reduced gloss.
X: Most of the ink receiving layer is scraped off.

<Drying time>
Measure the moisture content of the recording sheet with a non-contact infrared moisture meter, and measure the time from application to the end of drying when the moisture content of the coating liquid applied to the support is 8% or less. And drying time.

From the above results, it can be seen that according to the present invention, an ink jet recording material having high photo-like gloss without cracks, excellent ink absorbability and water resistance, and high productivity can be obtained. In particular, since the recording sheet 9 uses acetoacetyl-modified polyvinyl alcohol and unmodified polyvinyl alcohol in a mass ratio of 3/7 to 7/3, it is compared with the recording sheet 1 while maintaining a high level of cracking and gloss. When the coating liquid to be discarded was diluted, the fluidity was high and the waste liquid treatment was easy. The recording sheet 10 was very easy to be treated with the waste liquid like the recording sheet 9, but the cracks and glossiness were slightly inferior to the recording sheets 1 and 9, although they were at a level that was not a problem.
Since the recording sheet 11 did not contain a boron compound, low-temperature gelation did not occur, and the coating liquid flowed by the wind, so that cracks and gloss were slightly reduced. Since the recording sheet 12 did not contain a compound having two or more primary amino groups in the molecule, the waste liquid was easy to treat, but the crosslinking reaction with the binder having a keto group at the end of high temperature drying did not work effectively. Large cracks occurred and the gloss was remarkably lowered. The recording sheet 13 is a case where the compound is changed to a compound having one primary amino group in the molecule, and the waste liquid treatment was easy, but a large crack was generated on the entire surface, the gloss was remarkably lowered, and the water resistance of the ink receiving layer was also improved. It was not obtained. In the recording sheet 14, the pigment was changed to particles having a secondary particle diameter of 1.0 μm, but the gloss was remarkably lowered. The recording sheets 15 and 16 were obtained when the acetoacetyl-modified polyvinyl alcohol was changed to unmodified polyvinyl alcohol. The waste liquid treatment was easy, but large cracks occurred due to high temperature drying, and the water resistance was low. The recording sheets 8 and 17 were gelled at a low temperature and then dried under relatively mild conditions, and the waste liquid was easy to treat and a high gloss inkjet recording material without cracking was obtained. Therefore, it took about twice as long as the recording sheet subjected to high temperature drying. Further, in the recording sheet 17, the water resistance of the ink receiving layer was lowered.

Claims (3)

In a recording material in which at least one ink receiving layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder is provided on a support, the ink receiving layer contains 2 boron compounds and primary amino groups in the molecule. An inkjet recording comprising a compound having two or more hydrazide groups in the molecule as a compound having at least one and a modified polyvinyl alcohol having a keto group which is a resin binder having a keto group as a resin binder material. As the resin binder, a modified polyvinyl alcohol having a keto group and an unmodified polyvinyl alcohol which are a resin binder having a keto group, a modified polyvinyl alcohol having a keto group and an unmodified polyvinyl alcohol which are a resin binder having a keto group The inkjet recording material according to claim 1, wherein the mass ratio is 3/7 to 7/3. In the method for producing an inkjet recording material, on which a support is provided with at least one ink receiving layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder, a boron compound and a primary amino group are provided on the support. A coating liquid comprising a compound having two or more hydrazide groups in a molecule as a compound having two or more in the molecule and a modified polyvinyl alcohol having a keto group which is a resin binder having a keto group as a resin binder A method for producing an ink jet recording material, comprising: coating, gelling a coating solution with cold air of 10 ° C. or lower, and drying at a drying end temperature of 50 ° C. or higher.