JP2000247021A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium which is excellent in terms of brightness especially in a white paper part and a printed part, print density, ink absorbability, a recorded image quality or the like as suitability for ink jet recording and further, is of high surface strength. SOLUTION: A recording sheet has one or more recording layers formed on a substrate. In this case, any one of the recording layers contains a cationic copolymer containing a silanol group and a tertiary amino group or a quaternary ammonium base, and fine silica particles consisting of primary particles whose average particle size is 3-40 nm, and secondary particles whose average particle size is 10-500 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more particularly to an ink jet recording sheet which is excellent in glossiness and surface strength of a blank portion and a printed portion, and is excellent in ink jet recording suitability.

[0002]

2. Description of the Related Art Recording by an ink jet printer is as follows.
It is used in various fields because of low noise, high-speed recording, and easy multicoloring. As the ink jet recording paper, high quality paper devised to be rich in ink absorbency, coated paper having a surface coated with a porous pigment, or the like is applied. By the way, since all of these papers are mainly ink jet recording papers having a low surface gloss, so-called matte tone, there is a demand for ink jet recording papers having a high surface gloss and an excellent appearance. Generally, as a paper having a high surface gloss, a coated paper having a high gloss coated with a plate-like pigment on the surface and further subjected to a calender treatment as necessary, or a heating drum having a wet coating layer having a mirror surface There is known a so-called cast coated paper obtained by copying a mirror surface by pressing and drying on a surface. This cast coated paper has higher surface gloss and better surface smoothness compared to ordinary super calendered coated paper, and provides excellent printing effect. However, when it is used for ink jet recording paper, it has various difficulties.

That is, a conventional cast coated paper is generally disclosed in, for example, US Pat. No. 5,275,846, and a film-forming substance such as an adhesive in a pigment composition constituting the coated layer is coated on a mirror-coated drum surface of a cast coater. High gloss is obtained by copying On the other hand, the porosity of the coating layer is lost due to the presence of the film-forming substance, and the absorption of ink during ink jet recording is extremely reduced. In order to improve the ink absorbency, it is important that the cast coating layer is made porous so that the ink can be easily absorbed. For that purpose, it is necessary to reduce the film forming property. Reducing the amount of film-forming material results in a reduction in blank gloss. As described above, it was extremely difficult to simultaneously satisfy both the surface gloss of the cast coated paper and the suitability for inkjet recording.

As a method for solving the above problem, a monomer having an ethylenically unsaturated bond is polymerized on a base paper provided with a recording layer mainly containing a pigment and an adhesive.
A coating liquid containing a copolymer composition having a glass transition point of 0 ° C. or more as a main component is applied to form a coating layer for casting, and heating is performed while the coating layer for casting is in a wet state. The present inventors have found that a cast paper for ink jet recording having both excellent gloss and ink absorbability can be obtained by press-contacting and drying the finished mirror-surface drum (JP-A-7-89220).

[0005]

The present inventors have further found that
It has been found that gloss and extremely excellent print quality can be obtained by using fine silica secondary particles having a specific particle size in the cast coating layer (Japanese Patent Application No. Hei 9-13221).
issue). Gloss and extremely excellent print quality can be obtained by the above technology, but as a result of including a porous pigment in the coating layer on the base material, in order to have high ink absorption,
The surface strength has been reduced, causing various problems. For example,
When a paper pickup roll or the like installed in a transport unit of an ink jet printer hits the surface of glossy paper, the paper is pressed and the mold enters due to a problem.
For this reason, even if a high-quality inkjet recorded image is obtained,
As a result, the image quality deteriorates. In addition, the glossiness once obtained is reduced by various post-processes (printing, cutting, etc.) after the gloss processing, and this causes a reduction in print image quality.

The present invention provides an ink jet recording medium which is excellent in ink jet recording suitability such as glossiness, print density, ink absorbency, recording image quality and the like of a blank paper portion and a printing portion, and also has excellent surface strength.

[0007]

The present invention includes the following aspects. [1] In an ink jet recording paper having one or more recording layers provided on a base material, one of the recording layers is a cationic copolymer containing a silanol group and a tertiary amino group or a quaternary ammonium base, In addition, an ink jet recording medium containing fine silica particles having an average primary particle size of 3 nm or more and 40 nm or less and an average secondary particle size of 10 nm or more and 500 nm or less. [2] The cationic copolymer comprises (a) 60 to 99% by weight of a polymerizable vinyl monomer, and (b) a vinyl monomer having a tertiary amino group or a quaternary ammonium group in the molecule. 5-2
0% by weight and (c) 0.5 to 20% by weight of an ethylenically unsaturated silane monomer are copolymerized. [3] The ink jet recording body according to [1] or [2], wherein one of the recording layers is a layer (upper layer) on a side to which ink is applied, and is formed by a cast method. [4] The recording layer containing the cationic copolymer contains the pigment containing the silica fine particles, and the cationic copolymer is contained in an amount of 10 to 100 parts by weight based on 100 parts by weight of the total pigment. The inkjet recording material according to [1], [2] or [3], which is characterized in that: [5] (a) a polymerizable vinyl monomer is selected from the group consisting of styrene, vinyltoluene, α-methylstyrene, and alkyl (meth) acrylates having an alkyl group having 1 to 18 carbon atoms; The ink jet recording material according to [2], [3] or [4], which contains at least one selected from cationic copolymers. [6] The cationic copolymer contains a cationic monomer having a tertiary amino group or a quaternary ammonium group as a constituent monomer thereof, and the cationic monomer is represented by the general formula (I):

Embedded image (Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² and R
³ each independently represents an alkyl group having 1 to 4 carbon atoms,
X represents O (oxygen atom) or NH group, and R4 has 2 carbon atoms.
And 5 to 5 alkylene groups, each of which may have a hydroxyl group as a substituent. Or a quaternary ammonium salt thereof, which is at least one selected from the group consisting of dialkylaminoalkyl (meth) acrylates and dialkylaminoalkyl (meth) acrylamides represented by [1] to [1] to The inkjet recording material according to any one of [5].

[7] Layer on the side to which ink is applied (upper layer)
The ink-jet recording material according to any one of [1] to [6], wherein at least one undercoat layer containing a pigment and an adhesive is provided between the recording layer and the paper substrate. [8] At least one undercoat layer containing a pigment and an adhesive is provided on the base material, and then a coating liquid for an upper recording layer is applied on the undercoat layer and semi-dried. [1]-characterized by finishing by pressing and drying
The inkjet recording material according to any one of [7]. [9] Solid content 100 of semi-dried coating liquid for upper recording layer
[8] The ink-jet recording medium according to [8], containing 20 to 400 parts by weight of water based on parts by weight. [10] The cationic copolymer has an ethylenically unsaturated silane monomer, a vinyl monomer having a tertiary amino group or a quaternary ammonium group in the molecule, and an alkyl group having 1 to 6 carbon atoms. (Meth) acrylic acid alkyl ester 50
And a styrene monomer 50% by weight or more.
[1] to [9], which is a core-shell copolymer comprising 0 to 100% by weight and 0 to 50% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 8 to 12 carbon atoms. The ink-jet body according to any one of the above.

[11] In an ink jet recording paper having one or more recording layers provided on a base material, any one of the recording layers contains a monomer having a silanol group and a tertiary amino group or a quaternary ammonium base. A cationic copolymer obtained by polymerizing a monomer containing a monomer having silica fine particles having an average particle diameter of primary particles of 3 nm or more and 40 nm or less and an average particle diameter of secondary particles of 10 nm or more and 500 nm or less An ink jet recording material comprising particles.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies, the present inventors have found that by providing a coating layer containing specific silica fine particles and a specific cationic copolymer on a base material, the present invention is improved. The present inventors have found that an ink jet recording sheet excellent in gloss, ink jet recording suitability, and surface strength of a blank portion and a printed portion desired by the present invention can be obtained, and the present invention has been completed. That is, in the present invention, the specific silica fine particles are silica fine particles (substantially mainly of secondary particles).
Has an average particle size of 10 nm or more and 500 nm or less,
It is preferably from 10 nm to 400 nm, more preferably from 10 nm to 300 nm, still more preferably from 15 nm to 150 nm, and most preferably 20 nm.
It is adjusted to at least 100 nm. Silica fine particles 2
When the average particle diameter of the secondary particles exceeds 500 nm, the transparency of the coating layer is reduced, and the coloring property of the dye fixed in the coating layer is reduced, so that a desired print density cannot be obtained. Further, when silica fine particles having an extremely small average particle diameter of the secondary particles are used, the ink absorbency is reduced, and a desired image quality cannot be obtained.

The average particle size of the primary silica fine particles must be adjusted to 3 nm or more and 40 nm or less, preferably 5 nm to 30 nm, more preferably 7 nm to 20 nm. This primary particle is 3n
m, the gap between the primary particles becomes extremely small,
The ability to absorb solvents and dyes in the ink is reduced, and the desired image quality cannot be obtained. When the average primary particle diameter exceeds 40 nm, the aggregated secondary particles become large, the transparency of the coating layer is reduced, and the color development of the dye fixed in the coating layer is reduced. Is not obtained.

The cationic copolymer contained in the recording layer is
A cationic copolymer containing a tertiary amino group or a quaternary ammonium base and a silanol group, preferably (a) 60 to 99% by weight of a polymerizable vinyl monomer;
(b) 0.5 to 20% by weight of a vinyl monomer having a tertiary amino group or a quaternary ammonium group in the molecule, and (c) 0.5 to 20% by weight of an ethylenically unsaturated silane monomer Is a cationic copolymer obtained by copolymerizing a monomer mixture consisting of The polymerizable vinyl monomer (a) is a basic main component of the cationic copolymer, and provides a coating layer containing the cationic copolymer with adhesion to a support (or a lower layer). Imparts strength, mechanical stability and water resistance to the surface of the coating layer. Such a (a) polymerizable vinyl monomer is not particularly limited except that it does not have a tertiary amino group or a quaternary ammonium base in the molecule. , Vinyl toluene, α-methylstyrene, butadiene, isoprene, ethylene, vinyl halides such as vinyl chloride, vinyl bromide, vinylidene chloride, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl laurate , Vinyl esters such as vinyl versatate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( Alkyl groups such as lauryl (meth) acrylate and stearyl (meth) acrylate have 1 to 18 carbon atoms Certain alkyl (meth) acrylates, maleic esters such as (meth) acrylamide, dibutyl maleate and the like, and (meth) acrylonitrile can be exemplified. These vinyl monomers are used alone or as a mixture of two or more. Among them, particularly, styrene monomers such as styrene, vinyltoluene, α-methylstyrene and the like, and alkyl (meth) acrylates, in particular, the alkyl group has 1 to 4 carbon atoms (meth) ) Acrylic acid alkyl esters are preferably used in view of strength, mechanical stability, and water resistance of the resulting cationic copolymer.

The vinyl monomer (b) having a tertiary amino group or a quaternary ammonium group in the molecule has a tertiary amino group or a quaternary ammonium group in the molecule.
A polymerizable monomer containing a quaternary amino group or a quaternary ammonium base and a polymerizable vinyl group, and as a preferred example,
For example, general formula (I) can be exemplified.

[0014]

Embedded image

(Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ each independently represent an alkyl group having 1 to 4 carbon atoms, and X represents an O (oxygen atom) or an NH group. , R
4 represents an alkylene group having 2 to 5 carbon atoms, which may have a hydroxyl group as a substituent. )) And dialkylaminoalkyl (meth) acrylamides and dialkylaminoalkyl (meth) acrylamides. Such dialkylaminoalkyl (meth)
Specific examples of the acrylates include, for example, dimethylaminoethyl (meth) acrylate, diethylethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dimethylamino-2-hydroxypropyl (meth) acrylate, and the like. it can. Further, specific examples of dialkylaminoalkyl (meth) acrylamides include, for example, dimethylaminoethyl (meth) acrylamide and the like.

In addition to the above-mentioned amine monomers, dialkylaminoalkyl vinyl ethers such as dimethylaminoethyl vinyl ether and the like, 2-vinylpyridine, 4-vinylpyridine, 2-vinylimidazole, N-vinylimidazole And heterocyclic compounds having a vinyl group such as N-vinylpyrrolidone and the like. The above-mentioned amine monomers may be used alone or as a mixture of two or more kinds. In the present invention, the dialkylaminoalkyl (meth) acrylates represented by the general formula (I) are used as copolymerizable monomers. In terms of polymerization stability and the water resistance of the resulting cationic copolymer, and in particular, dialkylaminoalkyl (meth) acrylates in which the number of carbon atoms of the alkyl group in the dialkylamino group is in the range of 1 to 4 are preferable. Used. Also,
2-Hydroxy-3-methacryloxypropyltrimethylammonium chloride can be suitably used as a cationic vinyl monomer because its tertiary amino group is previously quaternary ammonium chloride and is water-soluble. . Such an amine monomer may be used for copolymerization without being neutralized with an acid as it is, but preferably a part or all of the amine monomer is neutralized with an appropriate acid and used as a quaternary salt for the copolymerization. It is preferable that the obtained copolymer is further neutralized with an acid, if necessary, to obtain a cationic copolymer.

In the present invention, such a cationic vinyl monomer is preferably contained in the monomer mixture in an amount of 0.5 to 1%.
-20% by weight, more preferably 1-10% by weight. When the amount is less than 0.5% by weight, the resulting cationic copolymer has insufficient cationicity, and the miscibility with the fine silica in the coating layer and the cationic resin to be blended as required is not sufficient. Will be enough. If the content is more than 20% by weight, the polymerization stability during copolymerization is poor, the occurrence of aggregates is increased, and the water resistance of the obtained coating layer is further deteriorated. The ethylenically unsaturated silane monomer (c) has an ethylenically unsaturated group in a molecule, has a hydrolyzable group bonded to a silicon atom in the molecule, and has a hydrogen atom bonded to a silicon atom in the molecule. A silane compound having a hydrolyzable group. Specific examples thereof include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyltris (β-methoxyethoxy) silane,
Allyltriethoxysilane, trimethoxysilylpropylallylamine, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- ( (Meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltris (β-methoxyethoxy) silane, N-β- (N-vinylbenzylamino) ethyl-γ
-Aminopropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, 3- (N-styrylmethyl-
2-aminoethylamino) propylmethoxysilane,
Examples thereof include (meth) acryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride, vinyltriacetoxysilane, and vinyltrichlorosilane.

In the process of copolymerizing such an ethylenically unsaturated silane monomer with another monomer, part or all of the hydrolyzable group bonded to the silicon atom undergoes hydrolysis. It forms a silanol group, reacts with the silica fine particles in the coating layer, generates Si-OR bond (R: polymer component), and enhances the binding force, thereby increasing the unprecedented surface strength. Excellent inkjet recording paper can be produced.

The above ethylenically unsaturated silane monomer is used in the monomer mixture in an amount of preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight. If the amount is less than 0.5% by weight, the bonding strength with the fine silica in the coating layer becomes weak, and the desired surface strength cannot be obtained. If the content is more than 20% by weight, the obtained copolymer has poor film formability and the gloss of the coating layer is insufficient. Further, since the ethylenically unsaturated silane monomer is expensive, it is disadvantageous in cost. The cationic copolymer of the present invention comprises a monomer comprising a polymerizable vinyl monomer (A), a cationic vinyl monomer (B) and an ethylenically unsaturated silane monomer (C) as described above. The body mixture is copolymerized in an aqueous medium in the presence or absence of an emulsifier or dispersant, and if necessary, the obtained copolymer is further neutralized with an acid to form a cationic copolymer. It can be obtained as an emulsion or an aqueous dispersion.

The method of copolymerizing the monomer mixture is not particularly limited, and may be a conventionally known ordinary method. Incidentally, in order to use the cationic vinyl monomer of the monomer mixture, when using an emulsifier, dispersant,
Nonionic or cationic ones are preferred. Also,
The copolymer particles may be particles composed of a core-shell polymer. In this case, since the silanol group which reacts with the silica fine particles and develops the excellent strength for the purpose of the present invention can be localized more in the shell portion, the total amount of the ethylenically unsaturated silane monomer is reduced. And it is easy to obtain a product with an excellent balance of quality.

The amount of the cationic copolymer to be added to the recording layer is from 10 to 1 per 100 parts by weight of the silica fine particles.
00 parts by weight is preferred. More preferably, it is 30 to 60 parts by weight. If the amount is less than 10 parts by weight, the effect of improving the surface strength tends to be poor. If the amount exceeds 100 parts by weight, there is a possibility that the print density and the ink absorbency may be reduced.

As a resin for the recording layer, a water-soluble resin (for example, polyvinyl alcohols such as polyvinyl alcohol, cation-modified polyvinyl alcohol, and silyl-modified polyvinyl alcohol, casein, soy protein, and synthetic resin) is used as an adhesive other than the above-mentioned cationic copolymer. Proteins, starch,
Cellulose derivatives such as carboxymethylcellulose and methylcellulose), styrene-butadiene copolymer,
Conjugated diene polymer latex such as methyl methacrylate-butadiene copolymer, water-dispersible resin such as vinyl copolymer latex such as styrene-vinyl acetate copolymer,
Water-based acrylic resins, water-based polyurethane resins, water-based polyester resins, and the like can be used in combination with other generally known and used adhesives in the coated paper field.

The recording layer (also referred to as a coating layer) preferably contains a cationic compound in addition to the above-mentioned cationic copolymer in order to fix a dye component in the ink. Examples of the cationic compound include a cationic resin and a low molecular weight cationic compound (eg, a cationic surfactant).
Can be exemplified. A cationic resin is preferred from the viewpoint of improving the print density, and can be used as a water-soluble resin or an emulsion. Further, it can be used as a cationic organic pigment in which the cationic resin is insolubilized by means of crosslinking or the like to form a particulate form. Such a cationic organic pigment, when polymerizing a cationic resin, copolymerizes a polyfunctional monomer to form a crosslinked resin, or a reactive functional group (hydroxyl group,
(A carboxyl group, amino group, acetoacetyl group, etc.)
It is made into a crosslinked resin by means such as radiation. Cationic compounds, especially cationic resins, may also serve as adhesives.

The following are examples of the cationic resin. Specifically, 1) polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, 2) acrylic resin having a secondary amine group, tertiary amine group, or quaternary ammonium group, 3)
Polyvinylamine, polyvinylamidines, 4) dicyan cation resin represented by dicyandiamide-formalin polycondensate, 5) polyamine cation resin represented by dicyandiamide-diethylenetriamine polycondensate, 6) epichlorohydrin-dimethylamine addition polymer , 7) dimethyldiallylammonium chloride-S
0 ₂ copolymer, 8) diallylamine salt -S0 ₂ copolymer,
9) dimethyldiallylammonium chloride polymer,
10) Cationic compounds such as polymer of allylamine salt, 11) polymer of quaternary salt of dialkylaminoethyl (meth) acrylate, and 12) copolymer of acrylamide-diallylamine salt. The cationic compound also has the effect of improving the printed image water resistance.

The cationic compound to be incorporated in the coating layer can be used in an amount of 1 to 100 parts by weight, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the pigment. If the amount is too small, the effect of improving the print density is difficult to be obtained, and if it is too large, the print density may be reduced or the image may be blurred. Whiteness, viscosity, in the coating composition for the coating layer
Pigments, defoamers, colorants, fluorescent brighteners, antistatic agents, preservatives and dispersants, and thickeners used in general printing coated paper and inkjet paper to control fluidity, etc. Various auxiliaries such as agents are appropriately added. Further, when a casting method using a heated mirror-surface drum or a film transfer method (including a method in which an upper layer is formed by using a smooth molding surface and is used as a casting method) as described below is used, a casting drum or a film is used. For the purpose of imparting releasability from
A release agent can be added.

The substrate used in the present invention is not particularly limited, and may be an acidic paper used for general coated paper,
Alternatively, a paper substrate such as neutral paper, various synthetic resin film sheets, laminated paper, and the like are appropriately used. However, when using a cast method or a film transfer method as described below,
It is preferable to use an air-permeable substrate, and a paper substrate or a resin film sheet having air permeability can be used.

The paper base is composed mainly of wood pulp and, if necessary, pigment. Wood pulp can use various chemical pulp, mechanical pulp, recycled pulp, etc.
The degree of beating of these pulp can be adjusted with a beater in order to adjust paper strength, suitability for papermaking, and the like. Pulp beating degree (freeness) is not particularly limited, but is generally 250 to 5
It is about 50 ml (CSF: JIS P-8121). The pigment (filler) is blended for the purpose of imparting opacity or the like or adjusting the ink absorption, and calcium carbonate, calcined kaolin, silica, titanium oxide, etc. can be used. In this case, the amount is preferably about 1 to 20% by weight. If it is too large, the paper strength may be reduced. Sizing agent as auxiliary,
A fixing agent, a paper strength enhancer, a cationizing agent, a retention improver, a dye, a fluorescent whitening agent and the like can be added. Further, in the size press step of the paper machine, starch, polyvinyl alcohol, cationic resin and the like can be applied and impregnated to adjust the surface strength, sizing degree, and the like. Size degree is 1 to 200
Seconds are preferred. If the size is low, wrinkles may occur during coating, which may cause operational problems.If the size is high, ink absorbency may decrease, ink strike-through may occur, or curling or cockling after printing may be significant. May be. The basis weight of the substrate is not particularly limited, but is 20 to 400 g / m ^2.
It is about.

The recording layer according to the present invention may be provided directly on the substrate, but it is preferable to provide at least one undercoating recording layer for the purpose of increasing the ink absorption capacity and absorption speed. The undercoat layer provided on the base material is mainly composed of a pigment and an adhesive. The pigment in the undercoat layer is kaolin, clay, calcined clay, amorphous silica (also called amorphous silica), synthetic amorphous silica, zinc oxide, aluminum oxide, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate , Alumina, colloidal silica, zeolite, synthetic zeolite, sepiolite,
Smectite, synthetic smectite, magnesium silicate,
One or more pigments known and used in the general coated paper manufacturing field such as magnesium carbonate, magnesium oxide, diatomaceous earth, styrene-based plastic pigment, hydrotalcite, urea resin-based plastic pigment, and benzoguanamine-based plastic pigment are used in combination. I can do it. Among these, it is preferable to use amorphous silica, alumina, and zeolite having high ink absorbability as main components.

Examples of the undercoat layer adhesive include proteins such as casein, soy protein, and synthetic protein; various starches such as starch and oxidized starch; polyvinyl alcohols such as polyvinyl alcohol, cationic polyvinyl alcohol, and silyl-modified polyvinyl alcohol; Water-soluble resins such as cellulose derivatives such as carboxymethylcellulose and methylcellulose,
Hydrophobic resins such as styrene-butadiene copolymer, conjugated diene polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, vinyl polymer latex such as ethylene-vinyl acetate copolymer, etc. Conventionally known adhesives used for coated paper may be used alone or in combination. The mixing ratio of the pigment and the adhesive depends on the type, but generally the pigment 1
The amount is adjusted in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight, with respect to 00 parts by weight. In addition, dispersants, thickeners, defoamers used in the production of general coated paper,
Various auxiliaries such as an antistatic agent and a preservative are appropriately added. A fluorescent dye and a colorant can be added to the undercoat layer.

The recording layer of the undercoat layer may contain a cationic compound for the purpose of fixing the dye component in the ink for ink jet recording. However, it is preferable to fix the ink dye to the upper recording layer provided on the undercoat layer as much as possible, since the printing (recording) density becomes higher,
For this purpose, it is preferable to mix a larger amount of the cationic compound in the upper layer than in the undercoat layer. More preferably, a cationic compound is blended only in the upper layer, and the cationic compound is substantially not present in the undercoat layer. The term “substantially absent” excludes the addition of a small amount of a cationic surfactant or the like as an auxiliary agent. When the cationic compound is blended only in the upper layer, and the cationic compound is not substantially present in the undercoat layer, the gloss when the upper layer is provided is most easily developed. When a composite of colloidal silica and a polymer resin obtained by polymerizing a monomer having an ethylenically unsaturated bond is blended in the undercoat layer, the gloss of the upper layer is more enhanced. The reason for this is not necessarily clear, but it is presumed that the presence of the composite suppresses penetration of the undercoat layer into the undercoat layer while maintaining the ink absorbency of the undercoat layer. Further, although the reason is not clear, there is a tendency that the releasability from the cast drum when the upper layer is provided by the casting method is improved.

Examples of the polymer resin obtained by polymerizing a monomer having an ethylenically unsaturated bond include methyl acrylate, ethyl acrylate, butyl acrylate,
Acrylic acid ester having 1 to 18 alkyl groups such as 2-ethylhexyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl Alkyl groups such as methacrylates having 1 to 18 carbon atoms, methacrylic acid esters, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl propionate, acrylamide, N-methylolacrylamide, ethylene And a polymer obtained by polymerizing an ethylenic monomer such as butadiene.

In an embodiment in which the glossiness of the upper layer is increased by a casting method using a heated mirror drum described later, the Tg (glass transition point) of the (co) polymer component is 40 ° C.
The above is preferable, and the range of 50 to 100 ° C. is more preferable. If the Tg is too low, the film formation will progress too much during drying,
Ink absorption may be slow and bleeding may occur. The polymer may be a copolymer using two or more kinds of ethylenic monomers as needed, or may be a polymer or a substituted derivative of the copolymer. Incidentally, examples of the substituted derivative include, for example, those having a carboxyl group or those having been rendered alkali-reactive.

The above polymer resin can be compounded with colloidal silica. The above-mentioned ethylenic monomer is polymerized in the presence of a silane coupling agent and the like in the presence of colloidal silica to form a composite by a Si-OR bond (R: polymer component) or, if necessary, modified by a silanol group or the like. The polymer resin and colloidal silica are reacted to form Si-
A method of forming a composite by an OR bond (R: a polymer component) may be mentioned. The composition for an undercoat layer composed of the above-mentioned materials is generally adjusted to a solid content concentration of about 5 to 50% by weight, and dried on a paper substrate in a dry weight of ^{2 to} 100 g / m ² , preferably 5 to 50 g / m ² . ^{About 2} , more preferably 10
Coating is performed so as to be about 20 g / m ² . If the coating amount is small, the ink absorbency may be poor, or the gloss may not be sufficiently obtained when the surface layer is provided.If the coating amount is large, the print density may decrease, or the strength of the coating layer may decrease. In some cases, powder may be easily dropped or scratched. The composition for the undercoat layer is coated and dried by various known and publicly-known coating devices such as a blade coater, an air knife coater, a roll coater, a brush coater, a chaplex coater, a bar coater, a lip coater, a gravure coater, and a curtain coater. You. Further, if necessary, the recording layer may be subjected to a smoothing process such as super calendering or brushing after drying.

When the above-mentioned coating solution for the upper layer is coated on the base material or the undercoat layer, various known materials such as a blade coater, an air knife coater, a roll coater, a brush coater, a champlex coater, a bar coater, and a gravure coater can be used. Coating device can be used. The coating amount of the upper layer is 1 to 30 g / m ^{2 as} a dry solid content, preferably 1.5 g / m ² .
To 20 g / m ^2, more preferably 3 to 15 g / m ^2. If the amount is less than 1 g / m ² , the print density and gloss may not be sufficiently obtained. If the amount is more than 30 g / m ² , the effect may be saturated, the drying may be burdened, and the operability may be reduced. When the glossiness of the recording layer is increased, a recording density and image quality equivalent to a silver halide photograph can be obtained. After coating the upper layer coating solution on the base material or the undercoat layer and drying, gloss can be imparted by smoothing treatment using a super calender or the like. In order to impart high gloss and excellent ink jet recording suitability, it is preferable to employ a cast method and a film transfer method described later.

The casting method means that a coating layer is dried on a smooth casting drum (a drum made of mirror-finished metal, plastic, glass, etc.), a mirror-finished metal plate, a plastic sheet or film, a glass plate, or the like. Then, the smooth surface is copied onto the coating layer to obtain a smooth and glossy coating layer surface. As a method of providing the upper layer by a casting method using a heated mirror drum in this, the above-mentioned upper layer coating liquid is applied on a substrate or an undercoat layer, and the coating layer is in a wet state. A method of pressing and drying the mirror drum heated in the middle, drying and finishing (wet casting method), a method of pressing once on the heated mirror drum and drying and finishing (rewet casting method) And the like. Alternatively, a method of directly applying a coating liquid for an upper layer onto a heated mirror-surface drum and then pressing and drying the substrate or an undercoat layer provided on the substrate to finish the coating (precast method) can also be adopted.

The temperature of the heated mirror drum is, for example, 50
To 150 ° C, preferably 70 to 120 ° C. Further, a film transfer method may be employed as the cast method. The film transfer method is defined as (a) applying the coating solution for a coating layer on a substrate or an undercoat layer, and stacking a smooth film or sheet while the coating layer is in a wet state. A method of peeling and finishing a smooth film or sheet after drying, or (b) applying a coating liquid on a smooth film or sheet and applying a coating layer (recording layer) or laminating While the substrate surface or the undercoat layer surface is in a wet state to some extent, this is a method in which the substrate is pressed against the substrate, dried, and then a smooth film or sheet is peeled off to finish. Compared to the film transfer method, the cast method using a heated mirror drum tends to have excellent surface smoothness, and is often advantageous in terms of productivity and cost.

In the case of a casting method using a heated mirror-surface drum, the above-mentioned coating liquid for an upper layer is applied on a substrate or an undercoat layer provided on the substrate, and this coating layer is dried to some extent, It is particularly preferable that the coated layer be pressed against the heated mirror drum and dried to finish while it is in a dry state, since a uniform coating layer is easily formed, an upper layer having high print density and excellent gloss is easily obtained. Here, semi-dried means a state in which the fluidity of the coating layer is almost lost but contains a large amount of water, and is 20 to 400% based on the absolute dry weight of the coating layer.
(That is, 20 to 40 parts by weight based on 100 parts by weight of the absolute dry weight of the coating layer
(Including 0 parts by weight of water), more preferably in the range of 50 to 200%. If the water content is low, the transfer of the mirror surface when pressed against the mirror drum (cast drum) becomes insufficient, and it is difficult for the gloss to be sufficiently exhibited. If the amount is too large, the coating layer is crushed when pressed against the mirror drum, and a uniform coating layer with a sufficient coating amount cannot be obtained, and the print density and gloss tend to be insufficient. Further, the coating layer is transferred to and adheres to the mirror-surface drum, causing a decrease in gloss, and the mirror-surface drum becomes dirty, which may cause a problem in operation.

The coating liquid for the coating layer (upper layer) of the present invention is applied onto a substrate or an undercoat layer provided on the substrate, and is applied to a mirror-surface drum heated while the undercoat layer is in a wet state. In the case of finishing by pressing and drying, a method of accelerating the immobilization of the upper layer coating solution can be adopted in order to obtain a uniform and sufficient coating amount of the coating layer. As this method, for example, (1) a gelling agent which promotes immobilization of the coating solution for the upper layer is blended in the base material or the undercoat layer, and (2) on the base material or the undercoat layer. Coating and impregnating a gelling agent that promotes the immobilization of the upper layer coating solution. (3) Applying the upper layer coating solution and then promoting the immobilization of the upper layer coating solution. Coating and impregnating the surface with a gelling agent, (4) blending a gelling agent in the upper layer coating solution that promotes immobilization in the process of drying the coating solution. . As such a gelling agent,
Examples thereof include boric acid and formic acid, which are crosslinking agents for the adhesive in the coating solution for the upper layer, and salts thereof, aldehyde compounds, and epoxy compounds. A composition similar to the upper layer coating composition,
After coating on a base material or an undercoat layer and drying or semidrying, a composition for an upper layer may be further coated on the coating layer and dried on a cast drum. After the upper layer is provided by cast finishing, a smoothing treatment can be further performed by a super calender or the like.

[0039]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto.
Parts and% in Examples are parts by weight and% by weight, respectively, unless otherwise specified. "Preparation of paper base material" wood pulp (LBKP; freeness 500
ml CSF) 100 parts, calcined kaolin (trade name: Ansilex, Engelhard & Minerals) 9 parts, commercial sizing agent 0.05 part, sulfuric acid band 1.5 parts, wet paper strength agent 0.5 parts, starch 0 .75 parts of papermaking material,
A paper substrate having a basis weight of 120 g / m ² was produced using a fourdrinier machine. The Stockigt sizing degree of this paper substrate was 10 seconds. This paper substrate was used in all examples and comparative examples of the present invention. "Production of cationic copolymer" [Cationic copolymer A] 60 parts of deionized water was heated to 70 ° C.
, And 0.2 parts of a polymerization initiator was added. Next, 40 parts of deionized water, 0.5 part of a cationic emulsifier (stearyltrimethylammonium chloride), 2 parts of a nonionic emulsifier (polyoxyethylene nonylphenyl ether) and 1 part of acetic acid
30 parts of methyl methacrylate, 60 parts of butyl acrylate, 5 parts of dimethylaminoethyl methacrylate (Light Ester DM; manufactured by Kyoeisha Chemical Co., Ltd.), and 5 parts of vinyltrimethoxysilane (KBM-503; Shin-Etsu Chemical Co., Ltd.) A monomer mixture (emulsion mixture) composed of 5 parts was continuously added dropwise over 3 hours. Thereafter, the temperature of the reaction mixture was maintained at 70 ° C. for 2 hours to terminate the polymerization. Thereafter, the reaction mixture was cooled to room temperature, and the pH was adjusted to 5 with hydrochloric acid to obtain a cationic copolymer emulsion.

[Cationic copolymer B] Deionized water 1
5 parts of a cationic polymer (copolymer of 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride and acrylamide) was added to 00 parts, and the mixture was heated to 70 ° C. and dissolved, and 0.2 part of a polymerization initiator was added. . The same monomer mixture as the cationic copolymer A was added dropwise thereto over 3 hours without using an emulsifier. Thereafter, the same treatment as that for the cationic copolymer A was carried out to obtain a soap-free type cationic copolymer emulsion.

[Cationic Copolymer C] In the same manner as the cationic copolymer A, 30 parts of methyl methacrylate, 60 parts of butyl acrylate, vinyltrimethylammonium chloride (Blenmer QA; manufactured by NOF Corporation) 5
And 5 parts of vinyltrimethoxysilane (KBM-503; manufactured by Shin-Etsu Chemical Co., Ltd.) to obtain a cationic copolymer emulsion. [Cationic copolymer D] As in the case of the cationic copolymer A, 60 parts of butyl acrylate, 30 parts of styrene,
Dimethylaminobutyl methacrylate (Light ester D
M; Kyoeisha Chemical Co., Ltd.) and vinyltrimethoxysilane (KBM-503; Shin-Etsu Chemical Co., Ltd.) 5 parts were used to obtain a cationic copolymer emulsion. [Cationic copolymer E] 40 parts of deionized water was heated to 80 ° C.
, And 0.2 parts of a polymerization initiator was added. A mixture of 20 parts of deionized water and 0.4 part of a cationic emulsifier (stearyltrimethylammonium chloride) was added to the mixture, and 38 parts of ethyl acrylate and methacrylic acid were added. Dimethylaminobutyl acid (light ester DM; manufactured by Kyoeisha Chemical Co., Ltd.), 1 part, vinyltrimethoxysilane (KBM-503; Shin-Etsu Chemical Co., Ltd.)
1 part) was continuously added dropwise over 1 hour, and the mixture was left standing for another 1 hour and cooled to prepare a hydrophilic seed particle emulsion. Next, a monomer solution in which 0.6 part of a polymerization initiator is dissolved in 6 parts of styrene is added to the seed particle emulsion at a temperature of 50 ° C., and the mixture is stirred at 50 ° C. for 30 minutes to be absorbed by the seed particles. Was. Then 8
The temperature was raised to 0 ° C. to start polymerization, and the reaction was performed for 20 minutes. Next, a styrene emulsion prepared by previously adding 54 parts of styrene to a mixture of 40 parts of deionized water and 0.6 part of a cationic emulsifier (stearyltrimethylammonium chloride) with stirring was continuously added dropwise over 3 hours. , Followed by 2 at 80 ° C
The emulsion was left to stand for a period of time to obtain an emulsion of a cationic core-shell polymer in which a styrene polymer was used as a core and a copolymer layer composed of ethyl acrylate, vinyltrimethoxysilane, and dimethylaminoethyl methacrylate was used as a shell layer.

[Preparation of Silica Fine Particles] [Silica Fine Particles A] Synthetic amorphous silica (trade name: Fine Seal X-45, manufactured by Tokuyama Co., Ltd .;
Using an aqueous dispersion having a particle size of 5 μm and a primary particle diameter of 15 nm, the pulverization operation was repeated using a pressure-type homogenizer (trade name: ultrahigh-pressure type homogenizer GM-1 manufactured by SMT) (pressurization: 500 kg / cm ^2). ). The average secondary particle size of the silica in the dispersion after the treatment was 50 nm, and the solid content concentration was 12% (the primary particle size remained at 15 nm). "Mixing of silica fine particles and cationic compound" In the following Examples and Comparative Examples, when mixing the above silica fine particles A and the cationic compound, after mixing and dispersing both to once aggregate the silica, In addition, a pressure homogenizer (S
MT Corp., trade name: ultra high pressure homogenizer GM-1)
Triturated with (pressure 500 kg / cm ^2), an average secondary particle size of the silica in the dispersion was treated to an average secondary particle diameter 50nm of the original silica fine particles (primary particle diameter As it is).

Example 1 A coating solution for an undercoat layer described below was applied on a paper base material by a dry weight of 12%.
g / m ² with an air knife coater.
Dried. Next, the following upper layer coating solution is applied on the above-mentioned undercoat layer with an air knife coater, dried for 20 seconds with cold air to be in a semi-dry state (moisture ratio 1 to the absolute dry amount of the coating layer).
50%), pressed against a mirror-surface drum having a surface temperature of 90 ° C., dried, and released to obtain a glossy inkjet recording paper. The coating amount of the upper layer at this time was 5 g in terms of solid content weight.
/ M ² . [Coating liquid for undercoat layer] (solids concentration 17%, parts are solids
Indicates parts by weight. ) Synthetic amorphous silica (Fine Seal X-60; manufactured by Tokuyama, average secondary particle diameter 6.0 μm, primary particle diameter 15 nm)
80 parts, 20 parts of zeolite (ToyoBuilder; manufactured by Tosoh, average particle size 1.5 μm), 20 parts of silyl-modified polyvinyl alcohol (R1130; manufactured by Kuraray), and a styrene-2 methylhexyl acrylate copolymer having a glass transition point of 75 ° C. Complex emulsion with colloidal silica having a particle diameter of 30 nm (copolymer and colloidal silica are mixed in a weight ratio of 4
0:60, the particle size of the emulsion is 80 nm) 40 parts,
2 parts of a fluorescent dye (WhitexBPSH; manufactured by Sumitomo Chemical).

[ Coating liquid for upper layer] (solids concentration 12%, parts
100 parts by weight of silica fine particles A, diallyldimethylammonium chloride-acrylamide copolymer (PAS-J
-81: 10 parts by Nitto Boseki Co., Ltd., cationic resin (PAA)
-HCL-3L; Nitto Boseki, polyallylamine) 5
Parts, 5 parts of a cationic resin (CP-91; diallyldimethylammonium chloride manufactured by SENKA), 60 parts of a cationic copolymer A, and 10 parts of a release agent (Pertor N-856; polyethylene wax, manufactured by Hyundai Chemical Industry Co., Ltd.).

Example 2 In the coating solution for surface layer used in Example 1, except that the number of parts of the cationic copolymer A was changed from 60 parts to 30 parts,
In the same manner as in Example 1, a gloss type ink jet recording paper was obtained. Example 3 A gloss type inkjet recording paper was prepared in the same manner as in Example 1 except that the number of parts of the cationic copolymer A was changed from 60 parts to 100 parts in the coating solution for the surface layer used in Example 1. Obtained.

Example 4 A gloss type ink jet recording paper was obtained in the same manner as in Example 1 except that the cationic copolymer B was used in the coating solution for the upper layer. Example 5 A gloss type inkjet recording paper was obtained in the same manner as in Example 1 except that the cationic copolymer C was used in the upper layer coating liquid. Example 6 A gloss type inkjet recording paper was obtained in the same manner as in Example 1 except that the cationic copolymer D was used in the coating solution for the upper layer.

Example 7 A gloss type ink jet recording paper was obtained in the same manner as in Example 1 except that the cationic copolymer E was used in the coating solution for the upper layer. Example 8 A gloss type inkjet recording paper was obtained in the same manner as in Example 1 except that the secondary particle diameter of the silica fine particles A was changed from 50 nm to 200 nm in the coating solution for the surface layer used in Example 1. Was. Comparative Example 1 In the same manner as in Example 1, except that the cationic copolymer was changed to polyvinyl alcohol (R-140H; manufactured by Kuraray Co., Ltd.) in the coating solution for the upper layer used in Example 1, a gloss type ink jet recording was performed. I got the paper. Comparative Example 2 Except that in the coating liquid for the upper layer used in Example 1, the cationic copolymer was changed to 30 parts of a cationic polyurethane resin having no silanol group (F-8564D; manufactured by Daiichi Kogyo Chemical). In the same manner as in Example 1, a gloss type ink jet recording paper was obtained. Comparative Example 3 In Comparative Example 2, the cationic polyurethane resin (F-85
64D; manufactured by Daiichi Kogyo Kagaku Co., Ltd.), except that the composition was changed to 60 parts, thereby obtaining a glossy type inkjet recording paper in the same manner as in Comparative Example 2.

Comparative Example 4 In the coating solution for the surface layer used in Example 1, the cationic copolymer was changed to a cationic acrylic ester copolymer resin having no silanol group (Polysol AE802; manufactured by Showa Polymer). A gloss type ink jet recording sheet was obtained in the same manner as in Example 1 except that the recording was performed. Comparative Example 5 In the coating solution for a surface layer used in Example 1, a gloss type was prepared in the same manner as in Example 1 except that the secondary particle diameter of the silica fine particles A was changed to 600 nm by changing the processing conditions of a pressure homogenizer. Was obtained. Comparative Example 6 A glossy inkjet recording paper was prepared in the same manner as in Example 1, except that the silica fine particles A were changed to a non-pulverized product (particle diameter: 4.5 μm) in the coating solution for the surface layer used in Example 1. I got

Example 9 The same coating liquid for undercoat layer as in Example 1 was applied on a paper base material by an air knife coater so as to have a dry weight of 12 g / m ² and dried. Next, the upper layer coating liquid used in Example 1 was applied on the above-mentioned undercoat layer with an air knife coater, dried, and then subjected to a heat super calender at a pressure of 50 kg.
The process was repeated twice to obtain a glossy inkjet recording paper. At this time, the coating amount of the upper layer was 5 g in terms of solid content weight.
/ M ² .

Example 10 The surface layer coating solution used in Example 1 was directly coated on a paper base material with an air knife coater, dried with cold air for 20 seconds to obtain a semi-dried state, and the surface temperature was reduced. It was pressed against a mirror-surface drum at 90 ° C., dried, and released to obtain a glossy inkjet recording paper. The coating amount at this time is 5 g in terms of solid content weight.
/ M ² .

COMPARATIVE EXAMPLE 7 The same procedure as in Example 1 except that an undercoat layer was provided was used.
Comparative Example 8 The base paper used in Example 1 was used as it was. Comparative Example 9 Except that the silica fine particles A were changed to colloidal silica (trade name: Snowtex O, manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex O, particle diameter: 10 to 20 nm) in the surface coating liquid used in Example 1, In the same manner as in Example 1, a gloss type ink jet recording paper was obtained.

The surface strength, suitability for ink jet recording and gloss of white paper of the ink jet recording paper thus obtained were evaluated by the following methods, and are shown in Table 1. [Surface strength] Friction tester specified in JIS-L0849
Using a type II (Gakushin type) (friction load: 200 g), a black paper was stuck to the friction element, and the glossy surface of the ink jet recording paper was reciprocally rubbed five times. The surface strength was determined according to the following criteria. ：: A little amount of paper powder adhered to black paper, and surface strength was high. −-: A level at which paper dust adheres to black paper but does not cause a problem. X: Paper powder adheres considerably to black paper, and the surface strength is extremely weak.

[Glossiness] The glossiness of a blank portion at 75 ° C. was measured according to JIS-P8142. [Visual glossiness] The glossiness was visually evaluated. : Excellent. −-: slightly inferior Δ: Poor. X: There is no glossiness at all. [Inkjet recording suitability] Inkjet printer B
Printing was performed using JC420J (a photo ink cartridge BC-22e manufactured by Canon Inc.). (Uniformity of solid printing portion) The printing unevenness (shading unevenness) of the solid printing portion in which two colors of cyan ink and magenta ink were mixed was visually evaluated. : Good level without printing unevenness −-: There is some printing unevenness, which is a level that is a little problem in practical use. X: A level at which printing unevenness is remarkable and becomes a serious problem in practical use.

(Print bleeding) Solid printing portions of black, cyan, magenta, and yellow inks were printed so that their borders were in contact with each other, and bleeding at the borders was visually evaluated. ：: Good level without bleeding. Δ: Slight bleeding, a level that is somewhat problematic in practical use. X: A level at which bleeding is remarkable and becomes a serious problem in practical use. (Print density after inkjet recording) The print density of the black solid print portion was measured by Macbeth RD-914.

[Comprehensive Evaluation] Print quality, gloss and surface strength were comprehensively evaluated. 5: Very good. 4: Excellent. 3: Normal. 2: Slightly inferior. 1: Poor.

[0056]

[Table 1]

[0057]

As is clear from the comparison between Examples 1 to 8 and Comparative Examples 1 to 6, ink jet recording provided with a coating layer containing the cationic copolymer defined by the present invention and silica fine particles. The paper has excellent inkjet recording suitability and gloss. Comparing Example 1 with Example 9, it can be seen that the quality (gloss, print density, etc.) is better when the upper layer is formed by the cast method. Comparing Example 1 with Example 10, it can be seen that the quality (bleeding, print density, etc.) is better when the undercoat layer is provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA13 FC06 2H086 BA16 BA33 BA34 BA45 4L055 AG18 AG28 AG62 AG63 AG64 AG65 AG71 AG73 AG89 AG94 AG98 AH50 AJ04 BE09 EA16 EA30 EA32 FA12 FA13 GA09 GA20

Claims (6)

[Claims] 1. An ink jet recording sheet having one or more recording layers provided on a substrate, wherein one of the recording layers is a cationic copolymer containing a silanol group and a tertiary amino group or a quaternary ammonium base. An ink jet recording material comprising coalesced particles and fine silica particles having an average primary particle size of 3 nm or more and 40 nm or less and an average secondary particle size of 10 nm or more and 500 nm or less. 2. A cationic copolymer comprising (a) 60 to 99% by weight of a polymerizable vinyl monomer and (b) a vinyl monomer having a tertiary amino group or a quaternary ammonium in the molecule. .5-
2. The ink jet recording material according to claim 1, wherein 20% by weight and (c) 0.5 to 20% by weight of an ethylenically unsaturated silane monomer are copolymerized. 3. The ink-jet recording medium according to claim 1, wherein one of the recording layers is a layer (upper layer) on a side to which ink is applied, and is formed by a cast method. 4. The recording layer containing the cationic copolymer contains a pigment containing the silica fine particles, and the total pigment 10
0 to 1 part by weight of the cationic copolymer is 10 to 1
4. The ink-jet recording material according to claim 1, wherein the content is 00 parts by weight. 5. A method according to claim 1, wherein (a) the polymerizable vinyl monomer is styrene,
At least one selected from the group consisting of vinyltoluene, α-methylstyrene, and alkyl (meth) acrylates having an alkyl group having 1 to 18 carbon atoms.
5. The ink-jet recording material according to claim 2, which contains a seed, a cationic copolymer. 6. The cationic copolymer contains, as a constituent monomer thereof, a cationic monomer having a tertiary amino group or a quaternary ammonium base, and the cationic monomer has a general formula (I) I) (Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² and R
³ each independently represents an alkyl group having 1 to 4 carbon atoms,
X represents O (oxygen atom) or NH group, and R4 has 2 carbon atoms.
And 5 to 5 alkylene groups, each of which may have a hydroxyl group as a substituent. ), And at least one selected from the group consisting of dialkylaminoalkyl (meth) acrylates and dialkylaminoalkyl (meth) acrylamides, and quaternary ammonium salts thereof. The inkjet recording material according to any one of the above.