JP2007245713A - Inorganic fine particle dispersion, manufacturing method of the same, inkjet recording medium, and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic fine particle dispersion having the stabilized viscosity of a coating liquid for an ink receiving layer and to provide an inkjet recording medium using the coating liquid for the ink receiving layer with the stabilized viscosity. <P>SOLUTION: In the method of manufacturing the inorganic fine particle dispersion, the dispersion includes at least one kind selected from the group comprising an inorganic fine powder, a silane coupling agent, a basic inorganic salt, and ammonia and the pH of the dispersion is adjusted by at least one kind selected from the group comprising an inorganic fine powder dispersion of pH of 5.0 or lower, a basic inorganic salt, and ammonium. In the method of manufacturing the inkjet recording media, the inkjet recording media includes at least one kind selected from the group comprising an inorganic fine powder, a silane coupling agent, a basic inorganic salt, and ammonia, and uses an inorganic fine powder dispersion of pH of 5.0 or lower. The inkjet recording media obtained by the method is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inorganic fine particle dispersion, a method for producing the same, an ink jet recording medium, and a method for producing the same.

In recent years, inkjet recording methods have the advantage that they can be recorded on various recording materials, the hardware (device) is relatively inexpensive and compact, and excellent in quietness. Widely used.
As an inkjet recording medium, an inkjet recording medium having an ink receiving layer having a porous structure has been proposed as a recording medium that forms a photo-like image, that is, a high-resolution image and exhibits high gloss.
However, since it has a porous structure, it has a high oxygen permeability and may promote deterioration of components contained in the ink receiving layer. Furthermore, image blurring over time may occur due to moisture adsorption on the silica surface contained in the ink receiving layer.

In order to solve the above problems, high-resolution and high-density images can be formed by using a silane coupling agent, and the image area is excellent in light resistance, water resistance, and gas resistance. An ink jet sheet has been proposed that stably retains an image without causing blurring of the image over time even when stored under a long period of time, and has excellent manufacturability (see, for example, Patent Document 1). ).
In addition, an invention using a silane coupling agent to provide environmental stability of an image has been proposed (see, for example, Patent Document 2 or 3).
JP 2003-305944 A Japanese Patent Laid-Open No. 2001-10209 Japanese Patent Laid-Open No. 2003-276305

The ink receiving layer is formed by applying an ink receiving layer coating solution on a support. However, when a silane coupling agent is added to the ink receiving layer coating solution, the viscosity of the ink receiving layer coating solution increases, and the viscosity stability may deteriorate.
The present invention has been made in view of the above-described conventional problems, and has an inorganic fine particle dispersion capable of improving the viscosity stability of a coating liquid for an ink receiving layer, a method for producing the same, and an excellent viscosity stability. An object of the present invention is to provide a method for producing an ink jet recording medium using a coating liquid for an ink receiving layer and an ink jet recording medium obtained by the method.

That is, the present invention
<1> An inorganic fine particle dispersion comprising inorganic fine particles, a silane coupling agent, at least one selected from the group consisting of a basic inorganic salt and ammonia, and having a pH of 5.0 or less.

  <2> The inorganic fine particle dispersion according to <1>, wherein the silane coupling agent is a cationic polymer silane coupling agent.

  <3> The inorganic fine particle dispersion described in <2>, wherein the cationic polymer type silane coupling agent is represented by the following general formula (1).

[In the general formula (1), R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ¹ , R ² and R ³ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. A is a repeating unit given from a cationic monomer, and B represents a repeating unit given from a nonionic monomer. m and n represent the mol% of A component and B component, respectively, and m and n are 0-100 mol% each independently. Further, the repeating unit represented by A and the repeating unit represented by B may be arranged in any order. ]

  <4> The inorganic fine particle dispersion according to <2>, wherein the cationic polymer type silane coupling agent is represented by the following general formula (2).

[In General Formula (2), R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ⁴ , R ⁵ and R ⁶ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. X represents a repeating unit provided from a cationic monomer, and Y represents a repeating unit provided from a nonionic monomer. r, p, and q represent mol% of each repeating unit, r is 1 to 50 mol%, and p and q are each independently 0 to 99 mol%. Further, the repeating unit represented by X and the repeating unit represented by Y may be arranged in any order. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

  <5> Any one of <1> to <4>, wherein the inorganic fine particles are at least one selected from the group consisting of silica fine particles, colloidal silica, alumina fine particles, and pseudoboehmite. The inorganic fine particle dispersion described.

  <6> A method for producing an inorganic fine particle dispersion having an inorganic fine particle, a silane coupling agent, at least one selected from the group consisting of a basic inorganic salt and ammonia, and having a pH of 5.0 or less, wherein the base PH is adjusted with at least one selected from the group consisting of inorganic inorganic salts and ammonia.

  <7> The production of the inorganic fine particle dispersion liquid according to <6>, further comprising a step of dispersing the inorganic fine particles in a solution containing at least one selected from the group consisting of the basic inorganic salt and ammonia. Is the method.

  <8> A method for producing an ink jet recording medium having an ink receiving layer comprising a water-soluble resin, inorganic fine particles, a silane coupling agent, a basic inorganic salt, and at least one selected from the group consisting of ammonia on a support. A step of preparing an inorganic fine particle dispersion having a pH of 5.0 or less, comprising at least one selected from the group consisting of inorganic fine particles, a silane coupling agent, a basic inorganic salt, and ammonia, and the inorganic fine particles A step of mixing the dispersion and the water-soluble resin to prepare an ink-receiving layer coating solution, and a step of coating the ink-receiving layer coating solution on the support to form a coating layer. This is a method for producing an ink jet recording medium.

  <9> The method for producing an ink jet recording medium according to <8>, wherein the silane coupling agent is a cationic polymer type silane coupling agent.

  <10> The method for producing an inkjet recording medium according to <9>, wherein the cationic polymer silane coupling agent is represented by the following general formula (1).

[In the general formula (1), R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ¹ , R ² and R ³ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. A is a repeating unit given from a cationic monomer, and B represents a repeating unit given from a nonionic monomer. m and n represent the mol% of A component and B component, respectively, and m and n are 0-100 mol% each independently. Further, the repeating unit represented by A and the repeating unit represented by B may be arranged in any order. ]

  <11> The method for producing an inkjet recording medium according to <9>, wherein the cationic polymer silane coupling agent is represented by the following general formula (2).

[In General Formula (2), R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ⁴ , R ⁵ and R ⁶ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. X represents a repeating unit provided from a cationic monomer, and Y represents a repeating unit provided from a nonionic monomer. r, p, and q represent mol% of each repeating unit, r is 1 to 50 mol%, and p and q are each independently 0 to 99 mol%. Further, the repeating unit represented by X and the repeating unit represented by Y may be arranged in any order. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

  <12> Any one of <8> to <11>, wherein the inorganic fine particles are at least one selected from the group consisting of silica fine particles, colloidal silica, alumina fine particles, and pseudoboehmite. It is a manufacturing method of the inkjet recording medium of description.

  <13> The method for producing an inkjet recording medium according to any one of <8> to <12>, wherein the water-soluble resin is a polyvinyl alcohol-based resin.

  <14> The method for producing an ink jet recording medium according to any one of <8> to <13>, wherein the ink receiving layer further contains a crosslinking agent capable of crosslinking the water-soluble resin. is there.

  <15> The method for producing an inkjet recording medium according to <14>, wherein the crosslinking agent is a boron compound.

  <16> At the same time as (1) applying the coating liquid to the coating layer, (2) before the coating layer is in the middle of drying, and (3) drying the coating layer. Any one of <8> to <15>, further comprising a step of applying a basic coating solution having a pH of 7.1 or higher at any time after the coating film is formed. The method for producing an inkjet recording medium according to the above.

  <17> An ink jet recording medium manufactured by the method for manufacturing an ink jet recording medium according to any one of <8> to <16>.

  According to the present invention, the inorganic fine particle dispersion capable of improving the viscosity stability of the ink receiving layer coating liquid, the production method thereof, and the ink jet recording medium using the ink receiving layer coating liquid excellent in viscosity stability. And an ink jet recording medium obtained by the method can be provided.

Hereinafter, the inorganic fine particle dispersion and the production method thereof, the inkjet recording medium and the production method thereof of the present invention will be described.
<Inorganic fine particle dispersion and method for producing the same>
The inorganic fine particle dispersion of the present invention comprises inorganic fine particles, a silane coupling agent, at least one selected from the group consisting of basic inorganic salts and ammonia, and has a pH of 5.0 or less.

  As will be described later, an ink-receiving layer coating solution is prepared by adding a water-soluble resin or the like to the inorganic fine particle dispersion of the present invention. There is little change in viscosity over time, and viscosity stability is excellent. By using the inorganic fine particle dispersion of the present invention, it is possible to obtain an ink-receiving layer coating solution having excellent viscosity stability.

The reason why the viscosity stability of the coating liquid for ink receiving layer is improved by using the inorganic fine particle dispersion of the present invention is not clear, but is presumed as follows. It is presumed that the viscosity of the ink receiving layer coating solution increases with time because the water-soluble resin contained in the coating solution is adsorbed on the inorganic fine particles. That is, the viscosity stability is expected to be improved by increasing the coating amount of the inorganic fine particles in the ink receiving layer coating solution with the silane coupling agent.
In the inorganic fine particle dispersion, the silane coupling agent is adsorbed on the surface of the inorganic fine particles, but the amount of adsorption is affected by the presence or absence of at least one compound selected from the group consisting of a basic inorganic salt and ammonia. The presence of the compound increases the amount of adsorption (covering amount) of the silane coupling agent on the surface of the inorganic fine particles. As a result, it is presumed that the viscosity stability of the ink receiving layer coating solution using the inorganic fine particle dispersion of the present invention is improved.
Moreover, since the amount of adsorption of the silane coupling agent to the surface of the inorganic fine particles increases, the amount of the silane coupling agent added can be reduced. Furthermore, since the viscosity change with time is reduced, the amount of the thickener used can be reduced.

Hereinafter, the constituent materials of the inorganic fine particle dispersion of the present invention will be described.
(Inorganic fine particles)
Examples of the inorganic fine particles contained in the inorganic fine particle dispersion of the present invention include silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, sulfuric acid. Calcium, pseudo boehmite, zinc oxide, zinc hydroxide, alumina, aluminum silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide, yttrium oxide and the like can be mentioned. Among these, silica fine particles, colloidal silica, alumina fine particles, or pseudoboehmite is preferable from the viewpoint of forming a good porous structure. The inorganic fine particles may be used as primary particles or in a state in which secondary particles are formed. The average primary particle size of these inorganic fine particles is preferably 2 μm or less, and more preferably 200 nm or less.
Further, silica fine particles having an average primary particle size of 20 nm or less, colloidal silica having an average primary particle size of 30 nm or less, alumina fine particles having an average primary particle size of 20 nm or less, or pseudoboehmite having an average pore radius of 2 to 15 nm is more preferable. In particular, silica fine particles, alumina fine particles, and pseudoboehmite are preferable.

  Silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to the production method. In the above wet method, a method is mainly used in which activated silica is produced by acid decomposition of a silicate, and this is appropriately polymerized and agglomerated and precipitated to obtain hydrous silica. On the other hand, the gas phase method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced by an arc in an electric furnace and oxidized with air. The method of obtaining anhydrous silica by the (arc method) is the mainstream, and “gas phase method silica” means anhydrous silica fine particles obtained by the gas phase method. As the silica fine particles used in the present invention, gas phase method silica fine particles are particularly preferable.

The gas phase method silica is different from hydrous silica in terms of the density of silanol groups on the surface, presence or absence of vacancies, and the like, and shows different properties, but is suitable for forming a three-dimensional structure having a high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is large at 5 to 8 / nm ² , and the silica fine particles tend to aggregate closely (aggregate). In the case of the method silica, the density of silanol groups on the surface of the fine particles is as small as ² to 3 / nm ² , so that it is sparse soft agglomeration (flocculate), resulting in a structure with a high porosity. Is done.

  Vapor phase silica has a particularly large specific surface area, so it has high ink absorption and retention efficiency, and its refractive index is low, so if it is dispersed to an appropriate particle size, it will provide transparency to the ink receiving layer. And high color density and good color developability can be obtained. The transparency of the ink-receiving layer is not only for applications that require transparency, such as OHP, but also for high color density and good color development gloss even when applied to recording sheets such as photo glossy paper. Is important.

  The average primary particle diameter of the vapor phase silica is preferably 30 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and most preferably 3 to 10 nm. Since the vapor phase silica is easily adhered to each other by hydrogen bonding with a silanol group, a structure having a large porosity can be formed when the average primary particle diameter is 30 nm or less, and ink absorption characteristics are effectively improved. Can be improved.

  Silica fine particles may be used in combination with the other fine particles described above. When the other fine particles and the vapor phase silica are used in combination, the content of the vapor phase silica in all the fine particles is preferably 30% by mass or more, and more preferably 50% by mass or more.

In the present invention, the inorganic fine particles are preferably alumina fine particles, alumina hydrate, a mixture or a composite thereof. Of these, alumina hydrate is preferable because it absorbs and fixes ink well, and pseudoboehmite (Al ₂ O ₃ .nH ₂ O) is particularly preferable. Alumina hydrates can be used in various forms, but it is preferable to use sol boehmite as a raw material because a smooth layer can be easily obtained.

About the pore structure of pseudo boehmite, the average pore radius is preferably 1 to 30 nm, and more preferably 2 to 15 nm. The pore volume is preferably 0.3 to 2.0 ml / g, more preferably 0.5 to 1.5 ml / g. Here, the pore radius and pore volume are measured by a nitrogen adsorption / desorption method, and can be measured by, for example, a gas adsorption / desorption analyzer (for example, trade name “Omni Soap 369” manufactured by Coulter). .
Among alumina fine particles, vapor-phase method alumina fine particles are preferable because of their large specific surface area. The average primary particle size of the vapor phase alumina is preferably 30 nm or less, and more preferably 20 nm or less.

  When the above-mentioned inorganic fine particles are used in an ink jet recording medium, for example, JP-A-10-81064, JP-A-10-119423, JP-A-10-157277, JP-A-10-217601, JP-A-11-348409, JP-A-2001-2001. 138621, 2000-43401, 2000-21235, 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, 8-2090 No. 8-2091, No. 8-2093, No. 8-174992, No. 11-192777, JP-A No. 2001-301314, etc. can be preferably used.

  The content of the inorganic fine particles in the inorganic fine particle dispersion of the present invention is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and particularly preferably 10 to 25% by mass.

(Silane coupling agent)
The silane coupling agent contained in the inorganic fine particle dispersion of the present invention is not particularly limited, and the silane coupling agent shown in the following specific examples can also be used, or a cationic polymer type silane coupling agent can be used. You can also.

  Here, R in 1-43 represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, an acyl group, a heteroaryl group, or a heterocyclic group, and n represents an integer of 1 or more.

  In the present invention, the cationic polymer type silane coupling agent refers to a silane coupling agent containing a repeating unit given from a cationic monomer. Examples of the cationic polymer type silane coupling agent used in the present invention include compounds represented by the following general formula (1) or general formula (2).

［一般式（１）中、Ｒ¹，Ｒ²，及びＲ³は、それぞれ独立に、水素原子、飽和あるいは不飽和環状構造を含んでいてもよい炭素数１から１８のアルキル基、飽和あるいは不飽和環状構造を含んでいてもよい炭素数１から８のアルコキシ基、又はアリールオキシ基を表し、Ｒ¹，Ｒ²，Ｒ³のうちの少なくとも一つはアルコキシ基あるいはアリールオキシ基であり、Ｑは、ヘテロ原子を介していてもよい総炭素数１から１８の２価の連結基を表し、置換基を有していてもよい。Ａは、カチオン性単量体から与えられる繰り返し単位であり、Ｂは非イオン性単量体から与えられる繰り返し単位を表す。ｍ、ｎはそれぞれＡ成分とＢ成分のモル％を表し、ｍおよびｎはそれぞれ独立に０〜１００モル％である。また、Ａで示される繰り返し単位とＢで示される繰り返し単位は、どのような順番で配置されていてもよい。］

[In the general formula (1), R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ¹ , R ² and R ³ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. A is a repeating unit given from a cationic monomer, and B represents a repeating unit given from a nonionic monomer. m and n represent the mol% of A component and B component, respectively, and m and n are 0-100 mol% each independently. Further, the repeating unit represented by A and the repeating unit represented by B may be arranged in any order. ]

The number of carbon atoms in the alkyl group represented by R ^1, R ^2, R ³ is 1 to 18, preferably 1-8. When the number of carbon atoms is 1 to 8, sufficient reactivity with inorganic fine particles can be ensured. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, and an octadecyl group. Groups are preferred.

The alkoxy group represented by R ¹ , R ² , or R ³ has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. Can be secured sufficiently. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, and an octyloxy group, and a methoxy group, an ethoxy group, and a propoxy group are preferable.

  In the general formula (1), Q represents a divalent linking group having 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. The total carbon number of Q is preferably 2-8. When the number of carbon atoms is 1 to 18, the solubility in water and alcohol solvents is sufficient, and sufficient performance can be ensured. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group, an ester group, an ether group, and an amide group. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a phosphorus atom, and an oxygen atom, a nitrogen atom, and a sulfur atom are preferable.

  Preferable specific examples of the divalent linking group include a methylene group, an ethylene group, a propylene group, a tetramethylene group, a hexamethylene group, and a xylylene group.

  In the general formula (1), A is at least one repeating unit given from a cationic monomer. Specific examples of the cationic monomer include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N, N -Dimethyl-N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-propyl-Np -Vinylbenzylammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N- Diethyl-N- N-Np-vinylbenzylammonium chloride, N, N-dimethyl-N- (4-methyl) benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-Np-vinyl Benzylammonium chloride, trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl -M-vinylbenzylammonium acetate, N, N, N-triethyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N, N-triethyl-N- -(3-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- ( 4-vinylphenyl) ethylammonium acetate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (Meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide The methyl chloride , Quaternized products of ethyl chloride, methyl bromide, ethyl bromide, methyl iodide or ethyl iodide, or sulfonates, alkyl sulfonates, acetates or alkyl carboxylates substituted with their anions.

  In the general formula (1), B is at least one repeating unit given from a nonionic monomer. Specific examples of nonionic monomers include, for example, (meth) acrylic acid alkyl esters [for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acrylic acid. Isopropyl, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, C1-C18 (meth) acrylic acid alkyl esters such as (meth) acrylic acid lauryl, stearyl (meth) acrylate, etc.], (meth) acrylic acid cycloalkyl esters [(meth) acrylic acid cyclohexyl etc.], ( Meth) acrylic acid aryl ester [phenyl (meth) acrylate, etc.], aralkyle Tellurium [benzyl (meth) acrylate], substituted (meth) acrylic acid alkyl esters [for example, 2-hydroxyethyl (meth) acrylate], (meth) acrylamides [for example, (meth) acrylamide, dimethyl (meta ) Acrylamide, etc.], aromatic vinyls [styrene, vinyl toluene, α-methyl styrene, etc.], vinyl esters [vinyl acetate, vinyl propionate, vinyl versatate, etc.], allyl esters [eg, allyl acetate], halogen-containing Monomers [vinylidene chloride, vinyl chloride, etc.], vinyl cyanides [(meth) acrylonitrile, etc.], olefins [ethylene, propylene, etc.] and the like.

  In general formula (1), the units represented by A and B may each be a single type or a combination of two or more types of copolymerizable components.

[In General Formula (2), R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ⁴ , R ⁵ and R ⁶ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. X represents a repeating unit provided from a cationic monomer, and Y represents a repeating unit provided from a nonionic monomer. r, p, and q represent mol% of each repeating unit, r is 1 to 50 mol%, and p and q are each independently 0 to 99 mol%. Further, the repeating unit represented by X and the repeating unit represented by Y may be arranged in any order. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

The R ^4, R ^5, the number of carbon atoms of the alkyl group represented by R ⁶ is 1 to 18, preferably 1-8. When the number of carbon atoms is 1 to 8, sufficient reactivity with inorganic fine particles can be ensured. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, and an octadecyl group. Groups are preferred.

The R ^4, R ^5, carbon atoms in the alkoxy group represented by R ⁶ is 1-8, preferably 1-4. When the number of carbon atoms is 1 to 8, sufficient reactivity with inorganic fine particles can be ensured. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, and an octyloxy group, and a methoxy group, an ethoxy group, and a propoxy group are preferable.

  J is a divalent linking group, and may be an alkylene group, an arylene group, an aralkylene group, —O—, —COO—, —OCO—, —CONH—, —CONR′—, or a combination thereof. Here, R ′ represents any of an alkyl group, an aryl group, and an aralkyl group.

  Specific examples of the monomer having a unit having a silyl group in the general formula (2) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (2-methoxyethoxy) silane, vinyldimethoxymethylsilane, 3-methacrylic acid. Examples include loxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropyldimethoxymethylsilane, and the like.

  In the general formula (2), X and Y have the same meanings as A and B in the general formula (1), respectively, and specific examples are the same.

In the inorganic fine particle dispersion of the present invention, it is preferable to use a cationic polymer type silane coupling agent represented by the general formula (1) or the general formula (2) as a silane coupling agent for the following reasons.
In the cationic polymer type silane coupling agent, covalent bonding to the silica surface by the silane coupling portion and electrostatic adsorption to the silica surface by the cationic site occur. Furthermore, since it is a polymer type, adsorption of PVA can be suppressed by steric hindrance, so that the viscosity of the coating solution can be stabilized efficiently.
Moreover, as content of the silane coupling agent in the inorganic fine particle dispersion liquid of this invention, 0.01-10 mass% is preferable, 0.1-5 mass% is more preferable, 0.2-3 mass% is Particularly preferred.

(Basic inorganic salt)
The inorganic fine particle dispersion of the present invention contains at least one selected from the group consisting of a basic inorganic salt and ammonia (hereinafter sometimes referred to as the alkali component of the present invention). In the present invention, the basic inorganic salt generally refers to a substance that dissolves in water and generates hydroxide ions.
Preferred specific examples of the alkali component of the present invention include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, trisodium phosphate, calcium hydroxide, barium hydroxide, calcium oxide, Examples thereof include barium oxide, ammonia, ammonium carbonate, ammonium chloride, magnesium hydroxide, copper (II) hydroxide, aluminum hydroxide, iron (III) hydroxide, and aluminum nitride, particularly preferably sodium hydroxide and potassium hydroxide. Sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonia, ammonium carbonate, ammonium chloride, magnesium hydroxide, and aluminum hydroxide.

  Moreover, water, an organic solvent, or these mixed solvents can be used as a solvent used for the inorganic fine particle dispersion of the present invention. Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, i-propanol and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate and toluene.

The pH of the inorganic fine particle dispersion of the present invention can be prepared using the alkali component of the present invention. The pH of the inorganic fine particle dispersion of the present invention is 5 or less, preferably 3 to 5, and particularly preferably 3.5 to 5.
In the inorganic fine particle dispersion of the present invention, it is most preferable that the inorganic fine particles are dispersed with a cationic polymer type silane coupling agent and the pH is adjusted to 4.0 to 4.5 using ammonium carbonate.

  In the method for producing an inorganic fine particle dispersion of the present invention, the pH is adjusted with the alkali component of the present invention. The pH adjustment method is not particularly limited, and the pH may be adjusted by adding the alkaline component of the present invention to a solution in which inorganic fine particles are dispersed, or the pH is adjusted in advance by the alkaline component of the present invention. Inorganic fine particles may be dispersed in the solution.

  For the production of the inorganic fine particle dispersion of the present invention, a disperser is used. Dispersers used to obtain the dispersion include various known dispersions such as a high-speed rotary disperser, a medium agitating disperser (such as a ball mill and a sand mill), an ultrasonic disperser, a colloid mill disperser, and a high pressure disperser. A stirrer, a colloid mill, or a high-pressure disperser is preferable from the viewpoint of efficiently dispersing the formed fine particles.

  The method for producing an inorganic fine particle dispersion of the present invention preferably includes a step of dispersing inorganic fine particles in a solution containing the alkali component of the present invention. A silane coupling agent may be added to the solution containing the alkali component of the present invention. By dispersing the inorganic fine particles in the solution containing the alkali component of the present invention, it is possible to prevent the generation of inorganic fine particles.

<Inkjet recording medium and manufacturing method thereof>
The method for producing an ink jet recording medium of the present invention comprises an ink receiving layer containing a water-soluble resin, inorganic fine particles, a silane coupling agent, a basic inorganic salt, and at least one selected from the group consisting of ammonia on a support. A method for producing an inkjet recording medium having the above-described step of preparing the inorganic fine particle dispersion of the present invention, and mixing the inorganic fine particle dispersion and the water-soluble resin to prepare a coating liquid for an ink receiving layer And a step of coating the ink receiving layer coating liquid on the support to form a coating layer. The ink jet recording medium of the present invention is produced by the method for producing an ink jet recording medium of the present invention.
Since the ink receiving layer coating liquid containing the inorganic fine particle dispersion of the present invention is excellent in viscosity stability over time, the use of the ink receiving layer coating liquid has the following advantages.
Even if the receiving layer is formed by using a coating solution that has been aged for 2 to 5 days, it is possible to reduce the manufacturing load because of the good surface shape.

The constituent materials of the ink receiving layer formed by the ink receiving layer coating liquid according to the present invention will be described below.
The ink receiving layer according to the present invention contains a water-soluble resin. When the ink receiving layer contains inorganic fine particles and a water-soluble resin, a porous structure is obtained, whereby the ink absorption performance is improved. In particular, if the solid content of the inorganic fine particles in the ink receiving layer is 50% by mass or more, more preferably more than 60% by mass, it is possible to form a more favorable porous structure, and sufficient ink absorption. This is preferable because an ink jet recording medium having the properties can be obtained. Here, the solid content in the ink receiving layer of the inorganic fine particles is a content calculated based on components other than water in the composition constituting the ink receiving layer.

(Water-soluble resin)
Examples of the water-soluble resin include polyvinyl alcohol resins that are resins having a hydroxy group as a hydrophilic structural unit [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified. Polyvinyl alcohol, polyvinyl acetal, etc.], cellulosic resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.] , Chitins, chitosans, starch, resins with ether linkages [polyethylene oxide (PEO), Propylene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like.
Moreover, the polyacrylic acid salt which has a carboxyl group as a dissociable group, maleic acid resin, alginate, gelatins, etc. can be mentioned.

Among these, polyvinyl alcohol resin is particularly preferable. Examples of the polyvinyl alcohol include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 3053231. JP-A-63-176173, JP-A-2604367, JP-A-7-276787, JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-18801, JP 2001-213045, JP 2001-328345, JP 8 -324105, JP-A-11-348417, etc. And the like.
Examples of water-soluble resins other than polyvinyl alcohol resins include the compounds described in paragraph Nos. 0011 to 0014 of JP-A No. 11-165461.
These water-soluble resins may be used alone or in combination of two or more.

  In the present invention, the content of the water-soluble resin is preferably 9 to 40% by mass, and more preferably 12 to 33% by mass with respect to the total solid content of the ink receiving layer.

In the present invention, the water-soluble resin and the inorganic fine particles, which mainly constitute the ink receiving layer, may each be a single material, or a mixed system of a plurality of materials may be used.
From the viewpoint of maintaining transparency, the type of water-soluble resin to be combined with fine particles, particularly silica fine particles, is important. When the gas phase method silica is used, the water-soluble resin is preferably a polyvinyl alcohol resin, more preferably a polyvinyl alcohol resin having a saponification degree of 70 to 100%, and a saponification degree of 80 to 99.5. % Of polyvinyl alcohol resin is particularly preferable.

The polyvinyl alcohol-based resin has a hydroxyl group in its structural unit, and since this hydroxyl group and the surface silanol group of the silica fine particle form a hydrogen bond, a three-dimensional network having a secondary particle of the silica fine particle as a network chain unit. It becomes easy to form a structure. By forming this three-dimensional network structure, it is considered that an ink receiving layer having a porous structure with a high porosity and sufficient strength is formed.
In ink jet recording, the porous ink receiving layer obtained as described above can absorb ink rapidly by a capillary phenomenon, and can form dots with good roundness without ink bleeding.

  In addition, the polyvinyl alcohol resin may be used in combination with the other water-soluble resin. When the other water-soluble resin and the polyvinyl alcohol resin are used in combination, the content of the polyvinyl alcohol resin in the total water-soluble resin is preferably 50% by mass or more, and more preferably 70% by mass or more.

(Content ratio of inorganic fine particles and water-soluble resin)
The mass content ratio [PB ratio (x / y)] of the inorganic fine particles (x) and the water-soluble resin (y) greatly affects the film structure and film strength of the ink receiving layer. That is, as the mass content ratio [PB ratio] increases, the porosity, pore volume, and surface area (per unit mass) increase, but the density and strength tend to decrease.

  In the present invention, the ink receiving layer prevents the decrease in film strength and cracking during drying caused by the PB ratio being too large as the mass content ratio [PB ratio (x / y)], and When the PB ratio is too small, the gap is easily blocked by the resin, and from the viewpoint of preventing the ink absorbency from being lowered due to the decrease in the porosity, 1.5 to 10 is preferable.

  Since stress may be applied to the recording sheet when passing through the conveyance system of the inkjet printer, the ink receiving layer needs to have sufficient film strength. Further, when cutting into a sheet shape, the ink receiving layer needs to have sufficient film strength in order to prevent cracking or peeling of the ink receiving layer. Considering these cases, the mass ratio (x / y) is more preferably 5 or less, while it is more preferably 2 or more from the viewpoint of ensuring high-speed ink absorbency in an inkjet printer.

For example, a coating solution in which vapor-phase method silica fine particles having an average primary particle size of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution at a mass ratio (x / y) of 2 to 5 is applied onto a support. When the coating layer is dried, a three-dimensional network structure is formed in which the secondary particles of silica fine particles are network chains, the average pore diameter is 30 nm or less, the porosity is 50 to 80%, and the pore specific volume is 0.00. A translucent porous film having a specific surface area of 5 ml / g or more and a specific surface area of 100 m ² / g or more can be easily formed.

(Crosslinking agent)
The ink receiving layer of the ink jet recording medium of the present invention includes a coating layer containing inorganic fine particles and a water-soluble resin, and further includes a cross-linking agent capable of cross-linking the water-soluble resin, and a crosslinking reaction between the cross-linking agent and the water-soluble resin. An embodiment that is a cured porous layer is preferred.

Boron compounds are preferred for the crosslinking of the water-soluble resin, particularly polyvinyl alcohol. Examples of the boron compound include borax, boric acid, borates (eg, _{orthoborate, InBO 3, ScBO 3, YBO} 3, LaBO 3, Mg 3 (BO 3) 2, Co 3 (BO 3) 2 , Diborate (eg, Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborate (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate _{(e.g., Na 2 B 4 O 7 ·} 10H 2 O), pentaborate _{(e.g., KB 5 O 8 · 4H 2} O, Ca 2 B 6 O 11 · 7H 2 O, CsB 5 O 5) include and the like Among them, borax, boric acid, and borate are preferable, and boric acid is particularly preferable in that a crosslinking reaction can be promptly caused.

The following compounds other than the boron compound can also be used as a crosslinking agent for the water-soluble resin.
For example, aldehyde compounds such as formaldehyde, glyoxal and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5- Active halogen compounds such as triazine and 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide) ), Active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; melamine resins (for example, methylolmelamine, alkylated methylolmelamine) ;Epoxy resin;

Isocyanate compounds such as 1,6-hexamethylene diisocyanate; aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983611; carboximide compounds described in US Pat. No. 3,100,704; glycerol triglycidyl Epoxy compounds such as ether; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; 2,3-dihydroxy Dioxane-based compounds such as dioxane; titanium-containing aluminum sulfate, chromium alum, potassium alum, metal-containing compounds such as zirconyl acetate, chromium acetate, polyamine compounds such as tetraethylenepentamine, hydrazide compounds such as adipic acid dihydrazide, A low molecule or polymer containing two or more oxazoline groups.
The above crosslinking agents may be used singly or in combination of two or more.

The application of the cross-linking agent is preferably performed as described below when a boron compound is taken as an example. That is, the ink receiving layer may be referred to as an ink receiving layer coating liquid (hereinafter referred to as “first coating liquid”) containing the inorganic fine particle dispersion of the present invention, a water-soluble resin containing polyvinyl alcohol, and a boron compound. ) Is a layer obtained by crosslinking and curing the coating layer, and (1) when the coating solution is applied to the coating layer, and (2) during the drying of the coating layer, the coating layer. Or (3) After the coating layer is dried and a coating film is formed, a basic coating liquid having a pH of 7.1 or higher (hereinafter referred to as “second coating”) It is preferable to carry out by applying a “liquid”.
1-50 mass% is preferable with respect to water-soluble resin, and, as for the usage-amount of a crosslinking agent, 5-40 mass% is more preferable.

(mordant)
In the present invention, a mordant is preferably contained in the ink receiving layer in order to improve the water resistance and aging resistance of the formed image.
As the mordant, a cationic polymer (cationic mordant) or an inorganic mordant is preferable as the organic mordant, and the liquid magenta having an anionic dye as a coloring material can be obtained by making the mordant present in the ink receiving layer. It can interact to stabilize the colorant and improve water resistance and aging resistance. The organic mordant and the inorganic mordant may be used alone or in combination with the organic mordant and the inorganic mordant.

  The mordant is added to the ink receiving layer coating liquid (first coating liquid) containing inorganic fine particles and a water-soluble resin, or if there is a concern of causing aggregation between the inorganic fine particles, the mordant is added to the second coating liquid. The method of containing and applying can be used. Also, a mordant can be added to both the first coating solution and the second coating solution. In this case, the mordant contained in the first coating liquid and the mordant contained in the second coating liquid may be the same or different.

As the cationic mordant, a polymer mordant having a primary to tertiary amino group or a quaternary ammonium base as a cationic group is preferably used, but a cationic non-polymer mordant may also be used. it can.
Examples of the polymer mordant include a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base (mordant monomer), and the mordant monomer and other monomers (hereinafter, What is obtained as a copolymer or condensation polymer with "non-mordant monomer") is preferred. Moreover, these polymer mordants can be used in any form of a water-soluble polymer or water-dispersible latex particles.

  Examples of the monomer (mordant monomer) include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N , N-dimethyl-N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-propyl-N -P-vinylbenzylammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-die Ru-N-benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N- (4-methyl) benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-N -P-vinylbenzylammonium chloride;

Trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl-m-vinyl Benzylammonium acetate, N, N, N-triethyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N, N-triethyl-N-2- (3-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride Tate;

N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N- Methyl chloride, ethyl chloride, methyl bromide of dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide , Quaternized products of ethyl bromide, methyl iodide or ethyl iodide, or sulfonates, alkyl sulfonates, acetates or alkyl carboxylates substituted with their anions.

  Specifically, for example, monomethyl diallyl ammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, triethyl- 2- (acryloyloxy) ethylammonium chloride, trimethyl-3- (methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl-2- (Methacryloylamino) ethylammonium chloride, trimethyl-2- (acryloylamino) ethyl Ammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride Triethyl-3- (acryloylamino) propylammonium chloride;

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride, N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl- 3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-3- And (acryloylamino) propylammonium acetate.
In addition, examples of copolymerizable monomers include N-vinylimidazole and N-vinyl-2-methylimidazole.

In addition, allylamine, diallylamine, its derivatives, salts and the like can be used. Examples of such compounds include allylamine, allylamine hydrochloride, allylamine acetate, allylamine sulfate, diallylamine, diallylamine hydrochloride, diallylamine acetate, diallylamine sulfate, diallylmethylamine and salts thereof (for example, Hydrochloride, acetate, sulfate, etc.), diallylethylamine and salts thereof (for example, hydrochloride, acetate, sulfate, etc.), diallyldimethylammonium salt (chloride, acetic acid as counter anions of the salt) Ion sulfate ions, etc.). In addition, since these allylamines and diallylamine derivatives are inferior in polymerizability in the amine form, they are generally polymerized in the form of a salt and desalted as required.
In addition, a unit such as N-vinylacetamide, N-vinylformamide or the like, which is converted into a vinylamine unit by hydrolysis after polymerization, and a salt thereof can also be used.

The non-mordant monomer does not contain a basic or cationic moiety such as a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, and does not show an interaction with a dye in an inkjet ink. Or the monomer which interaction is substantially small is said.
Examples of the non-mordant monomer include (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylate; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate; Aralkyl esters such as (meth) benzyl acrylate; Aromatic vinyls such as styrene, vinyl toluene and α-methylstyrene; Vinyl esters such as vinyl acetate, vinyl propionate and vinyl versatic acid; Allyl esters such as allyl acetate Halogen-containing monomers such as vinylidene chloride and vinyl chloride; vinyl cyanide such as (meth) acrylonitrile; olefins such as ethylene and propylene; and the like.

The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth) Propyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, Examples include 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like.
Of these, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate are preferable.
The non-mordant monomers can also be used singly or in combination of two or more.

Further, as the polymer mordant, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine and derivatives thereof, polyamide-polyamine resin, cationized starch, dicyandiamide formalin condensate, dimethyl 2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine, dicyandication resin typified by dicyandiamide-formalin polycondensate, polyamine cation resin typified by dicyanamide-diethylenetriamine polycondensate, epichlorohydrin-dimethylamine addition polymer, dimethyldiallylammonium chloride -SO ₂ copolymers, diallylamine salt -SO ₂ copolymer, Quaternary ammonium base-substituted alkyl group having an ester moiety (meth) acrylate-containing polymers, styryl polymers having a quaternary ammonium base-substituted alkyl group may be mentioned as being also preferred.

  Specific examples of the polymer mordant include JP-A Nos. 48-28325, 54-74430, 54-124726, 55-22766, 55-142339, 60-23850, and 60. -23851, 60-23852, 60-23853, 60-57836, 60-60643, 60-118834, 60-122940, 60-122941, 60-122294 No. 60-235134, JP-A-1-161236, U.S. Pat.Nos. 2,484,430, 2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386, 4,193,800, 4,273,853, JP 4282305, JP 4450224, JP-A-1-16123. 10-81064, 10-119423, 10-157277, 10-217601, 11-348409, JP-A-2001-138621, 2000-43401, 2000-212235 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, 8-2090, 8-2091, 8-2093, JP-A-8-174992, JP-A-11-192777, JP-A-2001-301314, JP-B-5-35162, JP-A-5-35163, JP-A-5-35164, JP-A-5-88846, JP-A-7-118333 JP-A-2000-344990, Japanese Patent Nos. 2648847, 2666177, etc. It is below. Of these, polyallylamine and derivatives thereof are particularly preferable.

  As the organic mordant in the present invention, polyallylamine having a weight average molecular weight of 100,000 or less and derivatives thereof are particularly preferable from the viewpoint of preventing bleeding with time.

  In the present invention, various known allylamine polymers and derivatives thereof can be used as polyallylamine or derivatives thereof. Examples of such derivatives include salts of polyallylamine and acids (acids include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, methanesulfonic acid, toluenesulfonic acid, acetic acid, propionic acid, cinnamic acid, (meth) Organic acids such as acrylic acid, or combinations thereof, or salts of only a part of allylamine), derivatives of polyallylamine by polymer reaction, copolymers of polyallylamine and other copolymerizable monomers Specific examples of the monomer include (meth) acrylic acid esters, styrenes, (meth) acrylamides, acrylonitrile, vinyl esters and the like.

  Specific examples of polyallylamine and derivatives thereof include JP-B-62-31722, JP-B-2-14364, JP-B-63-43402, 63-43403, 63-45721, 63-29881, Japanese Patent Publication Nos. 1-26362, No. 2-56365, No. 2-57084, No. 4-41686, No. 6-2780, No. 6-45649, No. 6-15592, No. 4-68622, Patents No. 3199227, No. 3008369, JP-A-10-330427, JP-A-11-21321, JP-A-2000-281728, JP-A-2001-106736, JP-A-62-256801, JP-A-7-173286, 7-213897, 9-235318, 9-302026, 11-21321, WO99 / 21901, WO99 / 19 72 No., JP-A-5-140213, compounds described in JP Kohyo No. 11-506488, and the like.

In the present invention, an inorganic mordant can be used as the mordant, and examples thereof include polyvalent water-soluble metal salts and hydrophobic metal salt compounds.
Specific examples of the inorganic mordant include, for example, magnesium, aluminum, calcium, scandium, titanium, vanadium, manganese, iron, nickel, copper, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, indium, barium, lanthanum, Examples thereof include salts or complexes of metals selected from cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysproprosium, erbium, ytterbium, hafnium, tungsten, and bismuth.

  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 Cupric, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, sulfuric acid Nickel ammonium hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum alum, basic polyaluminum hydroxide, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate Japanese, ferrous bromide, ferrous chloride, ferric chloride Ferrous sulfate, ferric sulfate, zinc phenolsulfonate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, titanium lactate, zirconium acetyl Acetonate, zirconyl acetate, zirconyl sulfate, ammonium zirconium carbonate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconium oxychloride, zirconium hydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, citric acid Magnesium nonahydrate, sodium phosphotungstate, sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, gallium nitrate , Strontium nitrate, strontium nitrate, yttrium acetate, yttrium chloride, yttrium nitrate, indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanum acetate, lanthanum benzoate, cerium chloride, cerium sulfate, cerium octylate, praseodymium nitrate, neodymium nitrate, nitric acid Examples include samarium, europium nitrate, gadolinium nitrate, dysprosium nitrate, erbium nitrate, ytterbium nitrate, hafnium chloride, and bismuth nitrate.

In the present invention, the inorganic mordant is preferably an aluminum-containing compound such as basic polyaluminum hydroxide, a titanium-containing compound, a zirconium-containing compound, or a group IIIB series metal compound (salt or complex).
Mordant amount contained in the ink receiving layer in the present invention is preferably from ^{0.01g / m 2 ~5g / m 2} , 0.1g / m 2 ~3g / m 2 is more preferable.

(Other ingredients)
The ink receiving layer according to the ink jet recording medium of the present invention may further contain various known additives such as acids, ultraviolet absorbers, antioxidants, fluorescent brighteners, monomers, polymerization initiators, and polymerization prohibitions, as necessary. Agents, anti-bleeding agents, preservatives, viscosity stabilizers, antifoaming agents, surfactants, antistatic agents, matting agents, anti-curling agents, water-proofing agents, and the like.

  In the present invention, the ink receiving layer may contain an acid. By adding an acid, the surface pH of the ink receiving layer is adjusted to 3 to 8, preferably 5 to 7.5. This is preferable because yellowing resistance of the white background portion is improved. The surface pH is measured by the A method (coating method) of the surface pH measurement determined by the Japan Paper Pulp Technology Association (J.TAPPI). For example, the measurement can be performed using a paper pH measurement set “Type MPC” manufactured by Kyoritsu Riken Co., Ltd. corresponding to the method A.

  Specific examples of acids include formic acid, acetic acid, glycolic acid, oxalic acid, propionic acid, malonic acid, succinic acid, adipic acid, maleic acid, malic acid, tartaric acid, citric acid, benzoic acid, phthalic acid, isophthalic acid , Glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, salicylic acid, salicylic acid metal salts (Zn, Al, Ca, Mg, etc.), methanesulfonic acid, itaconic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfone Acid, styrenesulfonic acid, trifluoroacetic acid, barbituric acid, acrylic acid, methacrylic acid, cinnamic acid, 4-hydroxybenzoic acid, aminobenzoic acid, naphthalenedisulfonic acid, hydroxybenzenesulfonic acid, toluenesulfinic acid, benzenesulfinic acid, Sulfanilic acid, sulfamic acid, α-le Examples include ricinic acid, β-resorcinic acid, γ-resorcinic acid, gallic acid, phloroglicin, sulfosalicylic acid, ascorbic acid, erythorbic acid, bisphenolic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, boric acid, boronic acid, etc. It is done. The amount of these acids added may be determined so that the surface pH of the ink receiving layer is 3-8.

  The above acids can be metal salts (eg sodium, potassium, calcium, cesium, zinc, copper, iron, aluminum, zirconium, lanthanum, yttrium, magnesium, strontium, cerium, etc.) or amine salts (eg ammonia, triethylamine, tri Butylamine, piperazine, 2-methylpiperazine, polyallylamine, etc.).

In the present invention, it is preferable that the ink receiving layer contains a preservability improving agent such as an ultraviolet absorbent, an antioxidant, or a bleeding inhibitor.
These UV absorbers, antioxidants, and bleeding inhibitors include alkylated phenol compounds (including hindered phenol compounds), alkylthiomethylphenol compounds, hydroquinone compounds, alkylated hydroquinone compounds, tocopherol compounds, thiodiphenyl ether compounds, 2 Compounds having the above thioether bonds, bisphenol compounds, O-, N- and S-benzyl compounds, hydroxybenzyl compounds, triazine compounds, phosphonate compounds, acylaminophenol compounds, ester compounds, amide compounds, ascorbic acid, amine antioxidants Agent, 2- (2-hydroxyphenyl) benzotriazole compound, 2-hydroxybenzophenone compound, acrylate, water-soluble or hydrophobic metal salt, organometallic compound, metal complex, Ndardamine compounds (including TEMPO compounds), 2- (2-hydroxyphenyl) 1,3,5, -triazine compounds, metal deactivators, phosphite compounds, phosphonite compounds, hydroxyamine compounds, nitrone compounds, peroxidation Scavenger, polyamide stabilizer, polyether compound, basic auxiliary stabilizer, nucleating agent, benzofuranone compound, indolinone compound, phosphine compound, polyamine compound, thiourea compound, urea compound, hydrazide compound, amidine compound, sugar compound, hydroxybenzoic acid Acid compounds, dihydroxybenzoic acid compounds, trihydroxybenzoic acid compounds and the like can be mentioned.

  Among these, alkylated phenol compounds, compounds having two or more thioether bonds, bisphenol compounds, ascorbic acid, amine-based antioxidants, water-soluble or hydrophobic metal salts, organometallic compounds, metal complexes, hindered amine compounds, Hydroxyamine compounds, polyamine compounds, thiourea compounds, hydrazide compounds, hydroxybenzoic acid compounds, dihydroxybenzoic acid compounds, trihydroxybenzoic acid compounds and the like are preferable.

  Specific examples of the compound include Japanese Patent Application Nos. 2002-13005, 10-182621, 2001-260519, 4-34953, 4-34513, and 11-170686. No. 4-34512, EP 1138509, JP-A-60-67190, JP-A-7-276808, JP-A-2001-94829, JP-A-47-10537, JP-A-58-111942, and JP-A-58-212844. 59-19945, 59-46646, 59-109055, 63-53544, JP 36-10466, 42-26187, 48-30492, 48-31255, 48-41572, 48-54965, 50-10726, U.S. Pat.Nos. 2,719,086, 3, 707,375, 3,754,919, 4,220,711,

  Japanese Patent Publication Nos. 45-4699, 54-5324, European Published Patent Nos. 223739, 309401, 309402, 3105301, 310552, 459416, German Published Patent No. 3435443, Kaisho 54-48535, 60-107384, 60-107383, 60-125470, 60-125471, 60-125472, 60-287485, 60-287486, 60-287487, 60-287488, 61-160287, 61-18854, 61-2111079, 62-146678, 62-146680, 62-146679, 62- No. 282885, No. 62-262047, No. 63-051174, Nos. 63-89877, 63-88380 same issue, same 66-88381 JP, same 63-113536 issue,

  63-163351, 63-203372, 63-224989, 63-251282, 63-267594, 63-182484, JP-A-1-239282, JP-A-2-262654, 2-71262, 3-121449, 4-291865, 4-291684, 5-611166, 5-119449, 5-188687, 5-188686, 5 No. 110490, No. 5-110437, No. 5-170361, No. 48-43295, No. 48-33212, U.S. Pat. Nos. 4,814,262, No. 4,980,275, and the like. .

The other components may be used alone or in combination of two or more. These other components may be added after being water-solubilized, dispersed, polymer-dispersed, emulsified or oil-dropped, or may be encapsulated in microcapsules. In the inkjet recording medium of the present invention, the addition amount of the other components is preferably 0.01 to 10 g / m ² .

In the present invention, the ink receiving layer coating solution preferably contains a surfactant. As the surfactant, any of cationic, anionic, nonionic, amphoteric, fluorine and silicon surfactants can be used.
Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers and polyoxyalkylene alkyl phenyl ethers (for example, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene nonyl). Phenyl ether, etc.), oxyethylene / oxypropylene block copolymers, sorbitan fatty acid esters (for example, sorbitan monolaurate, sorbitan monooleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (for example, polyoxyethylene sorbitan mono) Laurate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan Oleate, etc.), polyoxyethylene sorbitol fatty acid esters (eg, polyoxyethylene sorbitol tetraoleate), glycerin fatty acid esters (eg, glycerol monooleate), polyoxyethylene glycerin fatty acid esters (polyoxymonostearate) Ethylene glycerol, monooleic acid polyoxyethylene glycerin, etc.), polyoxyethylene fatty acid esters (polyethylene glycol monolaurate, polyethylene glycol monooleate, etc.), polyoxyethylene alkylamine, acetylene glycols (eg, 2, 4, 7) , 9-tetramethyl-5-decyne-4,7-diol, and ethylene oxide adducts and propylene oxide adducts of the diols), and the like. Sharp emission alkyl ethers are preferable. The nonionic surfactant can be used in the first coating solution and the second coating solution. Moreover, the said nonionic surfactant may be used independently and may use 2 or more types together.

  Examples of the amphoteric surfactants include amino acid type, carboxyammonium betaine type, sulfoammonium betaine type, ammonium sulfate betaine type, imidazolium betaine type, etc., for example, U.S. Pat. No. 3,843,368, Those described in JP-A-59-49535, JP-A-63-236546, JP-A-5-303205, JP-A-8-262742, and JP-A-10-282619 can be suitably used. As the amphoteric surfactant, an amino acid type amphoteric surfactant is preferable, and as the amino acid type amphoteric surfactant, as described in JP-A-5-303205, for example, an amino acid (glycine, glutamic acid, Histidine acid etc.) and N-aminoacyl acids and salts thereof into which long chain acyl groups have been introduced. The amphoteric surfactants may be used alone or in combination of two or more.

Examples of the anionic surfactant include fatty acid salts (eg, sodium stearate, potassium oleate), alkyl sulfate esters (eg, sodium lauryl sulfate, triethanolamine lauryl sulfate), and sulfonates (eg, sodium dodecylbenzenesulfonate). Alkyl sulfosuccinate (for example, sodium dioctyl sulfosuccinate), alkyl diphenyl ether disulfonate, alkyl phosphate, and the like.
Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, pyridinium salts, imidazolium salts and the like.

Examples of the fluorosurfactant include compounds derived from an intermediate having a perfluoroalkyl group using a method such as electrolytic fluorination, telomerization, or oligomerization.
Examples thereof include perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl trialkyl ammonium salts, perfluoroalkyl group-containing oligomers, and perfluoroalkyl phosphate esters.

  As the silicon-based surfactant, silicon oil modified with an organic group is preferable, and a structure in which a side chain of a siloxane structure is modified with an organic group, a structure in which both ends are modified, and a structure in which one end is modified can be taken. Examples of the organic group modification include amino modification, polyether modification, epoxy modification, carboxyl modification, carbinol modification, alkyl modification, aralkyl modification, phenol modification, and fluorine modification.

  In the present invention, the content of the surfactant is preferably 0.001 to 2.0%, more preferably 0.01 to 1.0% with respect to the coating liquid for the ink receiving layer. Further, when coating is performed using two or more liquids as the ink receiving layer coating liquid, it is preferable to add a surfactant to each coating liquid.

In the present invention, the ink receiving layer preferably contains a high boiling point organic solvent for curling prevention. The high-boiling organic solvent is an organic compound having a boiling point of 150 ° C. or higher at normal pressure, and is a water-soluble or hydrophobic compound. These may be liquid or solid at room temperature, and may be low molecules or polymers.
Specifically, aromatic carboxylic acid esters (for example, dibutyl phthalate, diphenyl phthalate, phenyl benzoate, etc.), aliphatic carboxylic acid esters (for example, dioctyl adipate, dibutyl sebacate, methyl stearate, dibutyl maleate) , Dibutyl fumarate, triethyl acetyl citrate, etc.), phosphate esters (eg, trioctyl phosphate, tricresyl phosphate, etc.), epoxies (eg, epoxidized soybean oil, epoxidized fatty acid methyl, etc.), alcohols (eg, stearyl) Alcohol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerol, diethylene glycol monobutyl ether (DEGMBE), triethylene glycol monobutyl ether, glycerol Methyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, triethanolamine, polyethylene glycol, etc. ), Vegetable oils (eg, soybean oil, sunflower oil, etc.) and higher aliphatic carboxylic acids (eg, linoleic acid, oleic acid, etc.).

(Support)
In the present invention, as the support, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used. In order to make use of the transparency of the ink receiving layer, it is preferable to use a transparent support or a highly glossy opaque support. Further, a read-only optical disk such as CD-ROM or DVD-ROM, a write-once optical disk such as CD-R or DVD-R, or a rewritable optical disk may be used as a support, and an ink receiving layer may be provided on the label surface side. it can.

The material that can be used for the transparent support is preferably a material that is transparent and can withstand radiant heat when used in an OHP or backlight display. Examples of the material include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
Although there is no restriction | limiting in particular as thickness of the said transparent support body, 50-200 micrometers is preferable at the point which is easy to handle.

  As the highly glossy opaque support, one having a glossiness of 40% or more on the surface on which the ink receiving layer is provided is preferable. The glossiness is a value determined according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard). Specifically, the following supports are mentioned.

For example, high gloss paper support such as art paper, coated paper, cast coated paper, baryta paper used for silver salt photographic support, etc .; polyesters such as polyethylene terephthalate (PET), nitrocellulose, cellulose acetate , Cellulose esters such as cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide are made opaque by adding a white pigment or the like (surface calendering may be applied). Glossy film; or a support in which a polyolefin coating layer containing or not containing a white pigment is provided on the surface of a highly glossy film containing the various paper supports, the transparent support or the white pigment. Etc.
A white pigment-containing foamed polyester film (for example, foamed PET containing polyolefin fine particles and forming voids by stretching) can also be suitably exemplified. Furthermore, resin-coated paper used for silver salt photographic printing paper is also suitable.

  Although there is no restriction | limiting in particular also about the thickness of the said opaque support body, 50-300 micrometers is preferable at the point of handleability.

  The surface of the support may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment or the like in order to improve wettability and adhesion.

Next, the base paper used for the resin-coated paper will be described in detail.
The base paper is made from wood pulp as a main raw material and, if necessary, paper using synthetic pulp such as polypropylene or synthetic fibers such as nylon or polyester in addition to wood pulp. As the above-mentioned wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, NUKP can be used, but more LBKP, NBSP, LBSP, NDP, LDP with more short fibers are used. preferable.
However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

  The pulp is preferably a chemical pulp (sulfate pulp or sulfite pulp) with few impurities, and a pulp having a whiteness improved by bleaching is also useful.

  In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancing agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, polyethylene glycols A water retaining agent such as a dispersant, a softening agent such as a quaternary ammonium, and the like can be appropriately added.

  The freeness of the pulp used for papermaking is preferably 200 to 500 ml as defined by CSF, and the fiber length after beating is a 24 mesh residual mass% and a 42 mesh residual as defined in JIS P-8207. 30 to 70% of the sum with the mass% of is preferable. In addition, it is preferable that the mass% of 4 mesh remainder is 20 mass% or less.

The basis weight of the base paper is preferably 30 to 250 g, and particularly preferably 50 to 200 g. The thickness of the base paper is preferably 40 to 250 μm. The base paper can be given a high smoothness by calendering at the paper making stage or after paper making. The density of the base paper is generally 0.7 to 1.2 g / m ² (JIS P-8118).
Furthermore, the base paper stiffness is preferably 20 to 200 g under the conditions specified in JIS P-8143.

A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, a sizing agent similar to the size that can be added to the base paper can be used.
The pH of the base paper is preferably 5 to 9 when measured by a hot water extraction method defined in JIS P-8113.

  The polyethylene covering the front and back surfaces of the base paper is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but some other LLDPE, polypropylene, etc. can also be used.

  In particular, the polyethylene layer on the side that forms the ink receiving layer is added with rutile or anatase type titanium oxide, fluorescent whitening agent, ultramarine, and polyethylene, as is widely done in photographic paper. Those having improved whiteness and hue are preferred. Here, as a titanium oxide content, about 3-20 mass% is preferable with respect to polyethylene, and 4-13 mass% is more preferable. Although the thickness of a polyethylene layer does not have limitation in particular, 10-50 micrometers is suitable for both front and back layers. Further, an undercoat layer can be provided on the polyethylene layer in order to provide adhesion to the ink receiving layer. As the undercoat layer, aqueous polyester, gelatin and PVA are preferable. Moreover, as thickness of this undercoat layer, 0.01-5 micrometers is preferable.

  Polyethylene-coated paper can be used as glossy paper, or when it is melt-extruded onto the surface of the base paper and coated, the matte surface or silky surface that can be obtained with ordinary photographic printing paper by so-called molding Can also be used.

A back coat layer can be provided on the support, and examples of components that can be added to the back coat layer include a white pigment, an aqueous binder, and other components.
Examples of white pigments contained in the backcoat layer include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, and aluminum silicate. , Diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, white inorganic pigment, styrene And organic pigments such as polyethylene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins.

Examples of the aqueous binder used in the back coat layer include styrene / maleate copolymer, styrene / acrylate copolymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxy Examples thereof include water-soluble polymers such as methyl cellulose, hydroxyethyl cellulose, and polyvinyl pyrrolidone, and water-dispersible polymers such as styrene butadiene latex and acrylic emulsion.
Examples of other components contained in the backcoat layer include an antifoaming agent, an antifoaming agent, a dye, a fluorescent brightening agent, a preservative, and a water-proofing agent.

The ink receiving layer according to the ink jet recording medium of the present invention is formed by applying the ink receiving layer coating liquid according to the present invention on a support to form a coating layer, and then performing a heat drying treatment or the like as necessary. (1) At the same time when the coating solution is applied to the coating layer, (2) before the coating layer is drying, and (3) the coating layer is being dried. It is preferable to further include a step of applying a basic coating solution having a pH of 7.1 or higher at any time after drying to form a coating film.
Providing an ink receiving layer that has been crosslinked and cured in this manner is preferable from the viewpoints of ink absorptivity and prevention of film cracking.

  This is preferable because a large amount of mordant is present near the surface of the ink receiving layer, so that the ink-jet coloring material is sufficiently mordanted and the water resistance of characters and images after printing is improved.

  The ink receiving layer coating liquid according to the present invention can be prepared by finely granulating a predetermined constituent material using a disperser. Dispersers used to obtain the dispersion include various known dispersions such as a high-speed rotary disperser, a medium agitating disperser (such as a ball mill and a sand mill), an ultrasonic disperser, a colloid mill disperser, and a high pressure disperser. A stirrer, a colloid mill, or a high-pressure disperser is preferable from the viewpoint of efficiently dispersing the formed fine particles.

  Moreover, water, an organic solvent, or these mixed solvents can be used as a solvent. Examples of the organic solvent that can be used for this coating include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. It is done.

Further, a dispersant may be added to improve the dispersibility of the coating solution. As the dispersant, a cationic polymer can be used. Examples of the cationic polymer include the aforementioned mordants. It is also preferable to use a silane coupling agent as the dispersant.
The amount of the dispersant added to the inorganic fine particles is preferably 0.1% by mass to 30% by mass, and more preferably 1% by mass to 10% by mass.

  The ink receiving layer coating solution is applied by a known coating method such as an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, or a bar coater. it can.

  Here, “before the coating layer exhibits a decreasing rate of drying” usually refers to a process for several minutes immediately after the coating of the coating liquid for the ink receiving layer, and during this time, the solvent in the coated coating layer This shows the phenomenon of “constant rate drying rate” in which the content of (dispersion medium) decreases in proportion to time. About the time which shows this "constant rate drying speed", it describes in chemical engineering handbook (pages 707-712, Maruzen Co., Ltd. issue, October 25, 1980), for example.

  As described above, after the application of the first coating solution, the coating layer is dried until the coating layer exhibits a decreasing rate of drying. This drying is generally performed at 50 to 180 ° C. for 0.5 to 10 minutes (preferably 0.5 to 5 minutes). The drying time naturally varies depending on the coating amount, but the above range is usually appropriate.

  As a method of applying the second coating liquid before the coating layer exhibits a reduced rate of drying, (1) a method of further coating on the coating layer, (2) a method of spraying by a method such as spraying (3) A method of immersing the support on which the coating layer is formed in the second coating solution.

  In the method (1), examples of the application method for applying the second application liquid include curtain flow coaters, extrusion die coaters, air doctor coaters, bread coaters, rod coaters, knife coaters, squeeze coaters, and reverse roll coaters. A known coating method such as a bar coater can be used. However, it is preferable to use a method in which the coater does not directly contact an already formed coating layer, such as an extrusion die coater, a curtain flow coater, a bar coater or the like.

  After the application of the second coating solution, it is generally heated at 40 to 180 ° C. for 0.5 to 30 minutes, and dried and cured. Especially, it is preferable to heat at 40-150 degreeC for 1 to 20 minutes.

  When the second coating liquid is applied at the same time as the first coating liquid is applied, the first coating liquid and the second coating liquid are supported so that the first coating liquid is in contact with the support. The ink-receiving layer can be formed by simultaneously applying (multilayer application) on the body and then drying and curing.

  The simultaneous coating (multilayer coating) can be performed by a coating method using, for example, an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried. In this case, the drying is generally performed by heating the coating layer at 40 to 150 ° C. for 0.5 to 10 minutes, preferably 40 to 100. It is carried out by heating at a temperature of 0.5 to 5 minutes.

  When the above simultaneous coating (multilayer coating) is performed by, for example, an extrusion die coater, the two types of coating liquid discharged at the same time are close to the discharge port of the extrusion die coater, that is, before moving onto the support. A multilayer is formed, and in that state, the multilayer is applied on the support. Since the two-layer coating liquid layered before coating is likely to cause a cross-linking reaction at the interface between the two liquids when transferred to the support, the two liquids to be ejected are mixed in the vicinity of the discharge port of the extrusion die coater. As a result, thickening is likely to occur, which may hinder the application operation. Therefore, when applying simultaneously as described above, simultaneously with the application of the first coating solution and the second coating solution, the barrier layer solution (intermediate layer solution) is interposed between the two solutions, and the simultaneous triple layer coating is performed. Is preferred.

  The barrier layer solution can be selected without particular limitation. For example, an aqueous solution containing a trace amount of water-soluble resin, water, and the like can be given. The water-soluble resin is used in consideration of applicability for the purpose of a thickener and the like. For example, a cellulose resin (for example, hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose) And polymers such as polyvinylpyrrolidone and gelatin. The barrier layer solution may contain the above mordant.

  After the ink receiving layer is formed on the support, the ink receiving layer is subjected to, for example, super calender, gloss calender, etc., and is subjected to calender treatment through the roll nip under heat and pressure, so that surface smoothness, glossiness, It is possible to improve transparency and coating strength. However, the calendar process may cause a decrease in the porosity (that is, the ink absorptivity may be decreased), so it is necessary to set conditions under which the decrease in the porosity is small.

As roll temperature in the case of performing a calendar process, 30-150 degreeC is preferable and 40-100 degreeC is more preferable.
Moreover, as a linear pressure between rolls at the time of a calendar process, 50-400 kg / cm is preferable and 100-200 kg / cm is more preferable.

In the case of ink jet recording, the thickness of the ink receiving layer needs to have an absorption capacity sufficient to absorb all of the droplets, and therefore needs to be determined in relation to the porosity in the layer. For example, if the ink amount is 8 nL / mm ² and the porosity is 60%, a film having a layer thickness of about 15 μm or more is required.
Considering this point, in the case of ink jet recording, the layer thickness of the ink receiving layer is preferably 10 to 50 μm.

The pore diameter of the ink receiving layer is preferably 0.005 to 0.030 μm, more preferably 0.01 to 0.025 μm in terms of median diameter.
The porosity and pore median diameter can be measured using a mercury porosimeter (trade name “Bore Sizer 9320-PC2” manufactured by Shimadzu Corporation).

In addition, the ink receiving layer is preferably excellent in transparency, as a guide, the haze value when the ink receiving layer is formed on a transparent film support is preferably 30% or less, More preferably, it is 20% or less.
The haze value can be measured using a haze meter (HGM-2DP: Suga Test Instruments Co., Ltd.).

  A polymer fine particle dispersion may be added to a constituent layer (for example, an ink receiving layer or a back layer) of the ink jet recording medium of the present invention. This polymer fine particle dispersion is used for the purpose of improving film properties such as dimensional stabilization, curling prevention, adhesion prevention, and film cracking prevention. The polymer fine particle dispersion is described in JP-A Nos. 62-245258, 62-1316648, and 62-110066. If a polymer fine particle dispersion having a low glass transition temperature (40 ° C. or lower) is used, cracking and curling of the layer can be prevented. Further, even when a polymer fine particle dispersion having a high glass transition temperature is added to the back layer, curling can be prevented.

The ink jet recording medium of the present invention is disclosed in JP-A-10-81064,
10-119423, 10-157277, 10-217601, 11-348409, JP-A-2001-138621, 2000-43401, 2000-212235, 2000-309157, Also produced by the methods described in JP-A Nos. 2001-96897, 2001-138627, JP-A Nos. 11-91242, 8-2087, 8-2090, 8-2091, and 8-2093. Is possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In the examples, “parts” and “%” represent “parts by mass” and “mass%” unless otherwise specified, and “average molecular weight” and “degree of polymerization” are “weight average molecular weight” and “mass”. It represents “average degree of polymerization”.

-Production of support-
50 parts of LBKP made of acacia and 50 parts of LBKP made of aspen were beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.

  Next, the pulp slurry obtained above was charged with 1.3% cationic starch (CATO 304L, manufactured by NSC Japan), 0.15% anionic polyacrylamide (polyaclon ST-13, manufactured by Hoshiko Chemical Co., Ltd.), and alkyl ketene dimer. (Arakawa Chemical Size Pine K) 0.29%, epoxidized behenamide 0.29%, polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd .: Arafix 100) 0.32%, then added antifoaming agent 0.12% was added.

In the process of making the pulp slurry prepared as described above with a long paper machine and pressing the felt surface of the web against the drum dryer cylinder through the dryer canvas, the tensile force of the dryer canvas is 1.6 kg / After drying by setting to cm, 1 g / m ² of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: KL-118) was applied on both sides of the base paper with a size press and dried, and then calendar treatment was performed. The base paper was made with a basis weight of 166 g / m ² to obtain a base paper (base paper) having a thickness of 160 μm.

After the corona discharge treatment was performed on the wire surface (back surface) side of the obtained base paper, high-density polyethylene was coated to a thickness of 25 μm using a melt extruder, and a thermoplastic resin layer comprising a mat surface was formed. (Hereinafter, this thermoplastic resin layer surface is referred to as “back surface”). The thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Sol 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (manufactured by Nissan Chemical Industries, Ltd.) Of “Snowtex O”) was dispersed in water at a mass ratio of 1: 2 so that the dry mass was 0.2 g / m ² .

  Furthermore, after the corona discharge treatment is applied to the felt surface (surface) side where the resin layer is not provided, anatase-type titanium dioxide 10%, a trace amount of ultramarine blue, and a fluorescent whitening agent 0.01% (vs. polyethylene) A low-density polyethylene containing MFR (melt flow rate) 3.8 is extruded using a melt extruder to a thickness of 29 μm, and a high gloss thermoplastic resin layer is formed on the surface side of the base paper. (Hereinafter, this high-gloss surface is referred to as a “front side”), which was used as a support.

-Preparation of inorganic fine particle dispersion-
1) Preparation of Inorganic Fine Particle Dispersion A Among the following compositions, (1) Gas phase method silica fine particles are added to an aqueous solution containing (2) ion-exchanged water, (3) polymer 1, and (4) ammonium carbonate. In addition, after dispersion using a non-media disperser (for example, an ultrasonic disperser (manufactured by SMT Co., Ltd.)), the dispersion is heated to 45 ° C. and held for 20 hours to hold inorganic fine particle dispersion A (dispersion A ) Was prepared.
[Composition of inorganic fine particle dispersion A]
(1) Gas phase method silica fine particles (inorganic fine particles) 10.0 parts (“VP-300SV” manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 7 nm)
(2) Ion-exchanged water 52.4 parts (3) Polymer 1 (silane coupling agent) (average molecular weight Mw: 20,000) 4.0 parts (25% ethanol solution) (the asterisk represents an adjacent repeating unit) Indicates the coupling position)

(4) Ammonium carbonate (manufactured by Kanto Chemical Co., Ltd.) 0.21 part

2) Preparation of dispersions B to Y In the same manner as the inorganic fine particle dispersion A, except that the amounts of the polymer 1 and ammonium carbonate used in the inorganic fine particle dispersion A were changed to the types and ratios shown in Table 1. Inorganic fine particle dispersions B to Y were prepared.

  Here, the Mw of the polymer 2 is 20,000, the Mw of the polymer 3 is 20,000, the Mw of the polymer 4 is 20,000, the Mw of the polymer 5 is 30,000, and the polymer 6 Mw: 50,000. Moreover, it is a: 50 and b: 50 of the polymer 3, a: 50 and b: 50 of the polymer 4, and a: 66 and b: 34 of the polymer 6.

[Example 1]
-Preparation of coating liquid A for ink receiving layer-
(1) The above-mentioned inorganic fine particle dispersion A, (2) boric acid, (3) polyvinyl alcohol solution, (4) ethanol (5) ion-exchanged water was added at 30 ° C., and the ink receiving layer coating liquid A (Coating liquid A) was prepared.
[Composition of coating liquid A for ink receiving layer]
(1) Inorganic fine particle dispersion A 66.7 parts (2) Boric acid 0.38 parts (3) Polyvinyl alcohol (water-soluble resin) solution 29.1 parts (4) Ethanol 2.6 parts (5) Ion exchange 4.3 parts of water

[Polyvinyl alcohol solution composition]
・ Kuraray Co., Ltd., “PVA235”, saponification degree 88%, polymerization degree 3500)
2.0 parts ・ Polyoxyethylene lauryl ether (surfactant)
("Emulgen 109P" (10% aqueous solution), HLB value 13.6 parts, manufactured by Kao Corporation) 0.75 parts diethylene glycol monobutyl ether 0.66 parts (Butisenol 20P, manufactured by Kyowa Hakko Co., Ltd.)
・ Thickener “EDTA-diamide” 0.055 parts ・ Ion-exchanged water 26.1 parts

−Preparation of inkjet recording medium−
The front surface of the support was subjected to corona discharge treatment, and then the ink receiving layer coating liquid A of Example 1 was applied at a coating amount of 183 ml / m ² . At that time, 8% by mass of a polyaluminum chloride aqueous solution (Alphain 83; manufactured by Daimei Chemical Industry Co., Ltd.) was mixed with the ink receiving layer coating solution A immediately before coating so that the coating amount was 12.0 ml / m ^2. And applied. Then, it was dried with a hot air dryer at 80 ° C. (wind speed 3 to 8 m / sec) until the solid content concentration of the coating layer became 20%. This coating layer exhibited a constant rate of drying during this period. And before showing the rate-decreasing drying, it was immersed in a basic coating solution C having the following composition for 3 seconds to deposit 13 g / m ² on the coating layer, and further dried at 80 ° C. for 10 minutes (curing). Process). Thus, an ink jet recording medium provided with an ink receiving layer having a dry film thickness of 32 μm was produced.

<Composition of basic solution C>
(1) Boric acid 0.65 parts (2) Zirconyl ammonium carbonate 2.5 parts (Zircosol AC-7 (28% aqueous solution), manufactured by Daiichi Rare Elemental Chemical Co., Ltd.)
(3) Ammonium carbonate (first grade; manufactured by Kanto Chemical Co., Inc.) 3.5 parts (4) Ion-exchanged water 63.3 parts (5) Polyoxyethylene lauryl ether (surfactant) 30.0 parts (Kao Corporation ), Emulgen 109P (2% aqueous solution), HLB value 13.6)

[Examples 2 to 11 and Comparative Examples 1 to 14]
Inkjet recording media of Examples 2 to 11 and Comparative Examples 1 to 14 were produced in the same manner as in Example 1 except that the inorganic fine particle dispersion was changed to that shown in Table 2. In addition, the coating liquid in which the viscosity on the next day of production exceeded 500 cp was diluted with ethanol and applied.

The inorganic fine particle dispersion, the ink receiving layer coating liquid and the ink jet recording medium obtained as described above were evaluated as follows. The obtained results are shown in Table 2.
(1) Measurement of pH of inorganic fine particle dispersion The pH was measured using a pH meter HM-25G (manufactured by Toa DKK Co., Ltd.).
(2) Dispersibility The dispersibility of the vapor phase silica fine particles when the inorganic fine particle dispersion was prepared was visually observed and evaluated based on the following criteria.
Good dispersibility (silica can be charged easily): ○
Dispersibility is slightly poor (silica takes time): △
Poor dispersibility (requires manual assistance from outside): ×
(3) Measurement of coating solution viscosity for ink receiving layer The viscosity of the coating solution for ink receiving layer was measured using a B-type viscometer (manufactured by Tokimec Co., Ltd.). The viscosity after 1 day of time was measured after the ink-receiving layer coating solution was prepared and then kept at 30 ° C. for 1 day using INCUBATOR: MIR-253 (manufactured by Sanyo Electric Co., Ltd.). The temperature of the liquid during the viscosity measurement was 30 ° C.
(4) Evaluation of surface state of ink jet recording medium The surface state of the ink jet recording medium prepared by coating was visually observed, and the following evaluation was performed.
No cracking: ○
There is a crack (L version size is around 5 failures): △
There is a crack (L version size is around 10 failures): ×

  It should be noted that the viscosity after 1 day with time in Comparative Examples 5 and 8 to 11 was not measurable because the coating solution gelled.

From Table 2, Examples 1 to 11 were excellent in dispersibility, and could not only lower the coating solution viscosity but also suppress the increase in coating solution viscosity over time. This is presumably because the pH of the dispersion was adjusted to a region where the adsorption rate of the silane coupling agent to silica was improved, and the silica particles were surrounded by more silane coupling agent to suppress the adsorption of PVA to silica. Is done.
In Comparative Examples 1, 3, 4, and 6, the viscosity of the coating solution increased to a level that could not be applied over time. This is presumably because the pH of the dispersion was not adjusted, so that the adsorption of the silane coupling agent to silica was insufficient, and the adsorption of PVA to silica could not be suppressed.
In Comparative Examples 2, 5, and 7, the viscosity of the coating solution increased, and the surface condition after coating was poor. This is because the adsorption rate of the silane coupling agent to silica can be improved by adjusting the pH of the dispersion, but the zeta potential between the silica particles decreases, the electrostatic repulsion between the silica particles weakens, and the silica particles aggregate. It is presumed that the conditions were easy.
Comparative Examples 8 to 14 did not have a viscosity stabilizing effect. This is presumed to be because, since a polymer having no binding site to silica is used, even if the pH is adjusted, only electrostatic repulsion between silica particles is weakened.

Claims (17)

  An inorganic fine particle dispersion comprising inorganic fine particles, a silane coupling agent, at least one selected from the group consisting of a basic inorganic salt and ammonia, and having a pH of 5.0 or less.   2. The inorganic fine particle dispersion according to claim 1, wherein the silane coupling agent is a cationic polymer type silane coupling agent. The inorganic fine particle dispersion according to claim 2, wherein the cationic polymer type silane coupling agent is represented by the following general formula (1).

[In the general formula (1), R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ¹ , R ² and R ³ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. A is a repeating unit given from a cationic monomer, and B represents a repeating unit given from a nonionic monomer. m and n represent the mol% of A component and B component, respectively, and m and n are 0-100 mol% each independently. Further, the repeating unit represented by A and the repeating unit represented by B may be arranged in any order. ] The inorganic fine particle dispersion according to claim 2, wherein the cationic polymer type silane coupling agent is represented by the following general formula (2).

[In General Formula (2), R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ⁴ , R ⁵ and R ⁶ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. X represents a repeating unit provided from a cationic monomer, and Y represents a repeating unit provided from a nonionic monomer. r, p, and q represent mol% of each repeating unit, r is 1 to 50 mol%, and p and q are each independently 0 to 99 mol%. Further, the repeating unit represented by X and the repeating unit represented by Y may be arranged in any order. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]   The inorganic fine particle dispersion according to any one of claims 1 to 4, wherein the inorganic fine particles are at least one selected from the group consisting of silica fine particles, colloidal silica, alumina fine particles, and pseudoboehmite. liquid. A method for producing an inorganic fine particle dispersion having an inorganic fine particle, a silane coupling agent, at least one selected from the group consisting of a basic inorganic salt and ammonia, and having a pH of 5.0 or less,
A method for producing an inorganic fine particle dispersion, wherein the pH is adjusted by at least one selected from the group consisting of the basic inorganic salt and ammonia.   The method for producing an inorganic fine particle dispersion liquid according to claim 6, further comprising a step of dispersing the inorganic fine particles in a solution containing at least one selected from the group consisting of the basic inorganic salt and ammonia. A method for producing an ink jet recording medium having an ink receiving layer comprising a water-soluble resin, inorganic fine particles, a silane coupling agent, a basic inorganic salt, and at least one selected from the group consisting of ammonia on a support,
A step of preparing an inorganic fine particle dispersion having a pH of 5.0 or less, comprising inorganic fine particles, a silane coupling agent, at least one selected from the group consisting of a basic inorganic salt and ammonia;
Mixing the inorganic fine particle dispersion and the water-soluble resin to prepare a coating liquid for an ink receiving layer;
Applying the ink receiving layer coating liquid onto the support to form a coating layer;
A method for producing an ink jet recording medium, comprising:   The method for producing an ink jet recording medium according to claim 8, wherein the silane coupling agent is a cationic polymer type silane coupling agent. The method for producing an ink jet recording medium according to claim 9, wherein the cationic polymer type silane coupling agent is represented by the following general formula (1).

[In the general formula (1), R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ¹ , R ² and R ³ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. A is a repeating unit given from a cationic monomer, and B represents a repeating unit given from a nonionic monomer. m and n represent the mol% of A component and B component, respectively, and m and n are 0-100 mol% each independently. Further, the repeating unit represented by A and the repeating unit represented by B may be arranged in any order. ] The method for producing an ink jet recording medium according to claim 9, wherein the cationic polymer type silane coupling agent is represented by the following general formula (2).

[In General Formula (2), R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms that may contain a saturated or unsaturated cyclic structure, saturated or unsaturated, Represents an alkoxy group having 1 to 8 carbon atoms which may contain a saturated cyclic structure, or an aryloxy group, and at least one of R ⁴ , R ⁵ and R ⁶ is an alkoxy group or an aryloxy group; Represents a divalent linking group having a total of 1 to 18 carbon atoms which may have a hetero atom, and may have a substituent. X represents a repeating unit provided from a cationic monomer, and Y represents a repeating unit provided from a nonionic monomer. r, p, and q represent mol% of each repeating unit, r is 1 to 50 mol%, and p and q are each independently 0 to 99 mol%. Further, the repeating unit represented by X and the repeating unit represented by Y may be arranged in any order. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]   The inkjet recording medium according to any one of claims 8 to 11, wherein the inorganic fine particles are at least one selected from the group consisting of silica fine particles, colloidal silica, alumina fine particles, and pseudoboehmite. Manufacturing method.   The method for producing an inkjet recording medium according to any one of claims 8 to 12, wherein the water-soluble resin is a polyvinyl alcohol-based resin.   The method for producing an ink jet recording medium according to claim 8, wherein the ink receiving layer further contains a cross-linking agent capable of cross-linking the water-soluble resin.   The method for producing an ink jet recording medium according to claim 14, wherein the crosslinking agent is a boron compound.   (1) At the same time that the coating solution is applied to the coating layer, (2) before the coating layer is in the process of drying and before the coating layer shows reduced-rate drying, or (3) the coating layer is dried and applied. 16. The inkjet recording according to claim 8, further comprising a step of applying a basic coating solution having a pH of 7.1 or higher at any time after the film is formed. A method for manufacturing a medium.   An ink jet recording medium manufactured by the method for manufacturing an ink jet recording medium according to claim 8.