JP2003292794A - Fine particle dispersion and inkjet recording sheet using the dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording sheet which has a quickdrying property and gives a high print concentration and high gloss, when printed with an inkjet printer. <P>SOLUTION: This inkjet recording sheet having a color material-receiving layer is characterized by containing a water-soluble polymer and a dispersion which contains a cationic polymer having an average mol.wt. of ≤60,000 and has a sulfate ion concentration of ≤1.5 wt.% based on the cationic polymer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ink such as an aqueous ink (using a dye or a pigment as a coloring material) and an oil-based ink, or a solid ink which is solid at room temperature and is melted and liquefied before printing. The present invention relates to a recording material supplied for ink jet recording using ink and the like, and a fine particle dispersion liquid used for the production thereof, and more specifically, to an ink jet recording sheet having high gloss and a high print density and a fine particle dispersion liquid used for the production thereof.

[0002]

2. Description of the Related Art In recent years, with the rapid development of the information technology industry, various information processing systems have been developed, and a recording method and a recording apparatus suitable for the information processing system have also been developed.
Each has been put to practical use. Among these recording methods, the inkjet recording method is not limited to offices, because it is capable of recording on various types of recording materials, has a relatively inexpensive hardware (device) and is compact, and has excellent quietness. , Has also been widely used in so-called home use.

Further, with the recent increase in resolution of ink jet printers, it has become possible to obtain so-called photograph-like high quality recorded matter. With the progress of such hardware (apparatus), ink jet recording has become possible. Various recording sheets have been developed. The properties required for the recording sheet for inkjet recording are generally (1) quick-drying property (high ink absorption speed), and (2) proper and uniform ink dot diameter. (No bleeding), (3) good graininess, (4) high dot roundness, (5) high color density, (6) high saturation (dullness No)), (7) Water resistance, light resistance, and ozone resistance of the printed area are good, (8) Whiteness of the recording sheet is high,
(9) The storage stability of the recording sheet is good (no yellowing coloring occurs even after long-term storage, images do not bleed after long-term storage (good aging blur)), and (10) stable and dimensional stability And the curl is sufficiently small, and (11) hard running property is good. Further, in the application of photo glossy paper used for the purpose of obtaining so-called photographic-like high quality recorded matter, in addition to the above-mentioned characteristics, gloss, surface smoothness, photographic paper-like texture similar to silver halide photography, etc. Is also required.

In order to improve the above-mentioned various properties, an inkjet recording sheet having a porous structure in the colorant receiving layer has been developed and put into practical use in recent years. Since such an inkjet recording sheet has a porous structure, it has excellent ink receptivity (quick drying) and high gloss.

For example, in JP-A-10-119423 and JP-A-10-217601, a coloring material receiving layer containing fine inorganic pigment particles and a water-soluble resin and having a high porosity is provided on a support. Ink jet recording sheets have been proposed. These recording sheets, particularly ink jet recording sheets provided with a coloring material receiving layer having a porous structure using silica as the inorganic pigment fine particles, have excellent ink absorbability due to the constitution and form a high resolution image. It is said that it has a high ink receiving performance to be obtained and can exhibit high gloss.

However, these are still unsatisfactory in terms of color density and glossiness similar to silver salt photographs.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording sheet which has a fast drying property, a high color density and a glossy feeling similar to a silver salt photograph when printed by an ink jet printer, and It is to provide a fine particle dispersion for this purpose.

[0008]

In view of such circumstances, the present inventors have conducted diligent research and found that in a dispersion liquid of fine particles having an average primary particle diameter of 50 nm or less, a cationic polymer contained in the dispersion liquid. Has an average molecular weight of 60,000 or less and a sulfate ion concentration of 1.5% by mass or less with respect to the cationic polymer, and an inkjet recording sheet containing a water-soluble resin in a colorant-receiving layer is The present invention has been completed by finding that it is dry, has a high color density, and gives a glossy feeling similar to that of a silver salt photograph. That is, the present invention provides the following.

<1> In a dispersion liquid of fine particles having an average primary particle diameter of 50 nm or less, the average molecular weight of the cationic polymer contained in the dispersion liquid is 60,000 or less, and the sulfate ion concentration is relative to that of the cationic polymer. Dispersion liquid of 1.5% by mass or less. <2> The dispersion according to <1>, wherein the cationic polymer is a polydiallyldialkyl cationic polymer. <3> Fine particles having an average primary particle diameter of 50 nm or less
The dispersion according to <1> or <2>, which is one kind or two or more kinds selected from silica fine particles, colloidal silica, alumina fine particles and pseudo-boehmite. <4> An ink jet recording sheet having a color material receiving layer, wherein the color material receiving layer is <1>, <2> or <3.
> An ink jet recording sheet comprising the dispersion described above and a water-soluble resin. <5> The inkjet recording sheet according to <4>, wherein the colorant receiving layer further contains a crosslinking agent capable of crosslinking the water-soluble resin. <6> The cross-linking agent is boric acid or a boron compound <5
> The inkjet recording sheet described above. <7> The colorant receiving layer is a layer having a three-dimensional network structure with a porosity of 50 to 80%, and the mass content ratio [PB ratio (x / y) of the fine particles (x) and the water-soluble resin (y). )] Is 1.5 to 10, the ink jet recording sheet according to <4>, <5> or <6>. <8> The colorant-receptive layer is a layer obtained by cross-linking and curing a coating layer applied with a coating liquid containing at least fine particles and a water-soluble resin, and the cross-linking and curing is performed on the coating liquid and / or the basic solution described below. When a cross-linking agent is added and (1) the coating solution is applied to form a coating layer, or (2) the coating layer formed by applying the coating solution is being dried, the coating layer is formed. At any time before indicates a rate-decreasing dryness, p
Any one of <4> to <7>, which is performed by applying a basic solution of H8 or more to the coating layer.
Ink jet recording sheet according to the item.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the ink jet recording sheet of the present invention, the coloring material receiving layer comprises the dispersion liquid of the present invention, a water-soluble resin,
In addition, by optionally containing a cross-linking agent, a mordant, etc., it is characterized in that it has fast drying property, high printing density, and high gloss feeling. Hereinafter, the present invention will be described in detail.

First, the dispersion liquid of the present invention will be described. (Fine particles) In the ink jet recording sheet of the present invention,
The coloring material receiving layer contains the dispersion liquid of the present invention and a water-soluble resin, and the fine particles in the dispersion liquid are constituent elements of the coloring material receiving layer of the inkjet recording sheet. The coloring material receiving layer of the ink jet recording sheet has a porous structure by containing fine particles, which improves the ink absorbing performance. In particular, when the solid content of the fine particles in the coloring material receiving layer is 50% by mass or more, more preferably more than 60% by mass, it becomes possible to form a better porous structure, and sufficient ink absorption is achieved. It is preferable since an inkjet recording sheet having the property can be obtained. Here, the solid content of the fine particles in the color material receiving layer is a content calculated based on components other than water in the composition constituting the color material receiving layer. The fine particles used in the present invention may be either organic fine particles or inorganic fine particles, but inorganic fine particles are preferable from the viewpoint of ink absorbability and image stability.

Preferred examples of the organic fine particles include polymer fine particles obtained by emulsion polymerization, microemulsion polymerization, soap-free polymerization, seed polymerization, dispersion polymerization, suspension polymerization and the like. , Polypropylene, polystyrene, polyacrylate, polyamide, silicone resin, phenol resin, natural polymer powder, latex or emulsion polymer particles, and the like.

Examples of the inorganic fine particles include silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, pseudoboehmite, and oxidation. Examples thereof include zinc, zinc hydroxide, alumina, aluminum silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide and yttrium oxide. Among these, silica fine particles, colloidal silica, alumina fine particles or pseudo-boehmite are preferable from the viewpoint of forming a good porous structure.

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

The above-mentioned vapor-phase process silica is different from the hydrous silica in the density of silanol groups on the surface, the presence or absence of pores, and the like, and shows different properties, but is suitable for forming a three-dimensional structure having a high porosity. ing. Although the reason for this is not clear, in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is as high as 5 to 8 / nm ² , and the silica fine particles are likely to be densely aggregated (aggregate). In the case of the method silica, since the density of silanol groups on the surface of the fine particles is as few as 2-3 / nm ^2, it is assumed that sparse soft agglomeration (flocculate) occurs, resulting in a structure with a high porosity. To be done.

Since the above-mentioned vapor grown silica has a particularly large specific surface area, it has high ink absorption and retention efficiency, and has a low refractive index. Is provided, and high color density and good color developability are obtained. The transparency of the receiving layer is not only for applications requiring transparency such as OHP, but also for obtaining high color density and good color forming gloss even when applied to recording sheets such as photo glossy paper. is important.

The average primary particle size of the vapor phase silica is 50 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, most preferably 3 to 10 nm. In the vapor phase silica, particles are easily attached to each other by hydrogen bonds due to silanol groups, so that a structure having a large porosity can be formed when the average primary particle diameter is 50 nm or less, and the ink absorption characteristics are effectively improved. Can be improved.

The silica fine particles may be used in combination with the above-mentioned other fine particles. When the other fine particles are used in combination with the vapor phase silica, 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.

As the inorganic fine particles used in the present invention, alumina fine particles, alumina hydrates, and mixtures or composites thereof are also preferable. Of these, alumina hydrate is preferable because it absorbs ink well and fixes it, and pseudo-boehmite (Al ₂ O ₃ .nH ₂ O) is particularly preferable. Although various forms of alumina hydrate can be used, sol-like boehmite is preferably used as a raw material because a smooth layer can be easily obtained.

Regarding the pore structure of pseudo-boehmite, its average pore radius is preferably 1 to 25 nm, and 2 to 10 nm.
Is more preferable. The pore volume is 0.3 to 2.0.
cc / g is preferable, and 0.5 to 1.5 cc / g is more preferable. Here, the measurement of the pore radius and the pore volume,
It is measured by a nitrogen adsorption / desorption method and can be measured by, for example, a gas adsorption / desorption analyzer (for example, trade name "Omnisorb 369" manufactured by Coulter, Inc.). Among the alumina fine particles, vapor phase method alumina fine particles are preferable because of their large specific surface area. The average primary particle diameter of the vapor grown alumina is 50 nm or less, and more preferably 20 nm or less.
Further, colloidal silica having an average primary particle size of 50 nm or less is also preferable. That is, as the inorganic fine particles used in the present invention, silica fine particles, colloidal silica, alumina fine particles and pseudo-boehmite are preferable.

When the above-mentioned fine particles are used in an ink jet recording sheet, for example, JP-A-10-81064 is used.
No. 10-119423 and No. 10-157277.
No. 10-217601 and No. 11-348409.
No. 2001-138621 and 2000-43.
401, 2000-212135, 2000-
309157, 2001-96897, 200
1-138627, JP-A-11-91242 and 8
-2087, 8-2090, 8-2091,
8-2093, 8-174992, 11-1
The embodiments disclosed in JP-A No. 92777, JP 2001-301314 A and the like can also be preferably used.

(Cationic Polymer) As the cationic polymer used in the dispersant of the present invention, as a cationic group,
A polymer having a primary to tertiary amino group or a quaternary ammonium base is preferably used. As the cationic polymer, a homopolymer of a monomer (cationic monomer) having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, or the cationic monomer and another monomer (hereinafter, Those obtained as a copolymer or a condensation polymer with "non-cationic monomer") are preferable. Further, these polymers can be used in the form of either water-soluble polymers or water-dispersible latex particles.

Examples of the above-mentioned monomer (cationic monomer) are 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-N-p-vinylbenzylammonium chloride, N, N-dimethyl-N
-N-propyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-octyl-N
-P-vinylbenzyl ammonium chloride, N, N
-Dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-benzyl-Np-vinylbenzylammonium chloride,
N, N-dimethyl-N- (4-methyl) benzyl-N-
p-vinylbenzyl ammonium 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
-Vinylbenzyl ammonium 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 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, Methyl chloride of N-diethylaminopropyl (meth) acrylamide,
Examples thereof include ethyl chloride, methyl bromide, ethyl bromide, quaternary compounds of methyl iodide or ethyl iodide, and sulfonates, alkylsulfonates, acetates or alkylcarboxylates of which anions are substituted.

Specifically, for example, monomethyldiallylammonium 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- (methacryloyl) Amino) ethylammonium chloride, trimethyl-
2- (acryloylamino) ethylammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (Acryloylamino) propyl ammonium chloride, triethyl-
3- (acryloylamino) propyl ammonium 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- (acryloylamino) propyl ammonium acetate etc. can be mentioned. In addition, as the copolymerizable monomer, N-vinylimidazole, N-vinyl-2-methylimidazole and the like can also be mentioned.

Further, allylamine, diallylamine, derivatives thereof, 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 (as the salt, for example, Hydrochloride, acetate, sulfate, etc.),
Examples thereof include diallylethylamine and salts thereof (for example, hydrochlorides, acetates, sulfates and the like), diallyldimethylammonium salts (for counter anions of the salts chloride, acetate ion sulfates and the like). Since these allylamine and diallylamine derivatives have poor polymerizability in the form of amine, it is common to polymerize in the form of a salt and desalt as necessary. Further, it is also possible to use a unit such as N-vinylacetamide or N-vinylformamide, which is converted into a vinylamine unit by hydrolysis after polymerization, or a salt thereof.

The non-cationic monomer does not contain a basic or cationic moiety such as a primary to tertiary amino group and its salt, or a quaternary ammonium salt group, and interacts with the dye in the ink jet ink. A monomer that does not show or has a substantially small interaction. Examples of the non-cationic 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 benzyl (meth) acrylate; aromatic vinyls such as styrene, vinyltoluene, α-methylstyrene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl versatate;
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.

The above-mentioned (meth) acrylic acid alkyl ester has a carbon number of 1 to 18 at the alkyl moiety (meth).
Acrylic acid alkyl esters are preferable, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate,
Examples include hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate. Among them, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and hydroxyethyl methacrylate are preferable. The above non-cationic monomers may be used alone or in combination of two or more.

Further, as the cationic polymer, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine and its derivatives, polyamide-polyamine resin,
Cationized starch, dicyandiamide formalin condensate, dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine, dicyan-based alkyne resin represented by dicyandiamide-formalin polycondensate, represented by dicyanamide-diethylenetriamine polycondensate polyamine cationic resins, epichlorohydrin - dimethylamine addition polymer, dimethyldiallylammonium phosphorus chloride -SO ₂ copolymers, diallylamine salt -SO ₂ copolymer, having a quaternary ammonium base-substituted alkyl group in the ester moiety (meth) An acrylate-containing polymer and a styryl-type polymer having a quaternary ammonium salt group-substituted alkyl group can also be mentioned as preferable ones.

Specific examples of the cationic polymer include those disclosed in JP-A-48-28325 and JP-A-54-74430.
No. 54-124726, No. 55-22766,
No. 55-142339, No. 60-23850, No. 6
0-23851, 60-2852, 60-2
3853, 60-57836, 60-6064.
No. 3, No. 60-118834, No. 60-122940
No. 60-122941, No. 60-122942
No. 60-235134, JP-A-1-161236.
Publications, US Pat.
No. 4, No. 3148061, No. 3309690, No. 4
115124, 4124386, 419380
No. 0, No. 4273853, No. 4282305, No. 4
450224, JP-A-1-161236, 10-
81064, 10-119423, 10-15
7277, 10-217601, 11-348.
409, JP 2001-138621 A, 2000
-43401, 2000-212135, 20
00-309157, 2001-96897, 2001-138627, and JP-A-11-91242.
No. 8-2087, 8-2090, 8-20
91, 8-2093, 8-174992, 11-192777, and JP 2001-301314A.
No. 5, Japanese Patent Publication No. 5-35162, No. 5-35163, No. 5-35164, No. 5-88846, JP-A 7-11
No. 8333, JP 2000-344990 A, Patent No. 2
Examples thereof include those described in each publication such as 648847 and 2661677. Among them, polyallylamine and its derivatives are preferable, and structurally, diallyldimethyl cationic polymer is preferable.

As the polyallylamine or its derivative, various known allylamine polymers and their derivatives can be used. Examples of such derivatives include salts of polyallylamine and an acid (as the acid, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, methanesulfonic acid, toluenesulfonic acid, acetic acid, propionic acid, cinnamic acid, (meth) Organic acids such as acrylic acid, or combinations thereof, or salts obtained by partially salting allylamine), derivatives of polyallylamine by polymer reaction, copolymers of polyallylamine and other copolymerizable monomers (such as Specific examples of the monomer include (meth) acrylic acid esters, styrenes,
(Meth) acrylamides, acrylonitrile, vinyl esters and the like).

Specific examples of polyallylamine and its derivatives include JP-B-62-31722 and JP-B-2-1.
No. 4364, Japanese Patent Publication No. 63-43402, No. 63-434
03, 63-45721, 63-29881,
Japanese Patent Publication No. 1-263632, No. 2-56365, No. 2-5
7084, 4-41686, 6-2780, 6-45649, 6-15592, 4-6862.
No. 2, Patent No. 3199227, No. 30083369,
JP-A-10-330427, JP-A-11-21321,
JP-A-2000-281728, 2001-1067
36, JP-A-62-256801, JP-A-7-17
No. 3286, No. 7-213897, No. 9-23531
No. 8, No. 9-302026, No. 11-21321,
The compounds described in WO99 / 21901, WO99 / 19372, JP-A-5-140213, and JP-A-11-506488 may be mentioned.

The cationic polymer in the present invention is preferably a diallyldialkyl cationic polymer,
A diallyldimethyl cationic polymer is particularly preferable. As the cationic polymer in the present invention, a cationic polymer having a weight average molecular weight of 60,000 or less, particularly 40,000 or less is preferable from the viewpoint of dispersibility, particularly prevention of thickening.

(Sulfate ion) The sulfate ion concentration in the dispersion of the present invention must be 1.5% by mass or less in order to prevent thickening of the dispersion. This sulfate ion is contained in the polymerization initiator and the like during the production of the cationic polymer, and this remains in the polymer. Therefore, it is desirable to use a polymerization initiator or the like that does not emit sulfate ions.

As the solvent of the dispersion liquid, water, an organic solvent, or a mixed solvent thereof can be used. 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, toluene and the like. To be

The amount of the above cationic polymer added to the fine particles is preferably 0.1% by mass to 30% by mass,
1% by mass to 10% by mass is more preferable. In order to produce the dispersion liquid of the present invention, KDL-P manufactured by Shinmaru Enterprises Co., Ltd. is prepared by adding fine particles and a cationic polymer to a solvent (for example, silica fine particles in water are 10 to 20% by mass).
Examples of the method include using ILOT for dispersion.

Further, in the preparation of the dispersion liquid containing the fine particles and the cationic polymer, the fine particle dispersion liquid may be prepared in advance and the dispersion liquid may be added to the cationic polymer solution, or the cationic polymer solution may be added to the fine particle dispersion liquid. They may be added or mixed at the same time. Further, instead of the fine particle dispersion liquid, fine particles of powder may be added to the cationic polymer solution as described above. A fine particle dispersion can be obtained by mixing the fine particles and the cationic polymer and then finely granulating the mixed solution using a disperser. As a disperser used to obtain the aqueous dispersion, various conventionally known dispersers such as a high-speed rotation disperser, a medium stirring type disperser (ball mill, sand mill, etc.), an ultrasonic disperser, a colloid mill disperser, a high-pressure disperser, etc. You can use a disperser,
From the viewpoint of efficiently dispersing the formed lump-shaped fine particles, a medium stirring type disperser, a colloid mill disperser or a high pressure disperser is preferable.

Next, the ink jet recording sheet of the present invention will be described. The ink jet recording sheet of the present invention has a coloring material receiving layer, the dispersion of the present invention, a water-soluble resin,
In addition, by containing a cross-linking agent, a mordant, etc., if necessary, fast drying property, high printing density and high gloss feeling can be obtained.

(Water-Soluble Resin) The water-soluble resin used in the present invention is, for example, a polyvinyl alcohol resin which is a resin 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 resin [methyl cellulose (MC),
Ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CM)
C), hydroxypropylcellulose (HPC), hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, etc.], chitins, chitosans, starch, resins having an ether bond [polyethylene oxide (PEO), polypropylene oxide (PPO),
Polyethylene glycol (PEG), polyvinyl ether (PVE), etc.], a resin having a carbamoyl group [polyacrylamide (PAAM), polyvinylpyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like. Further, polyacrylic acid salts having a carboxyl group as a dissociative group, maleic acid resins, alginates, gelatins and the like can also be mentioned.

Among the above, polyvinyl alcohol resins are particularly preferable. Examples of the polyvinyl alcohol include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432.
No. 7-29479, Japanese Patent No. 2537827
No. 7, Japanese Patent Publication No. 7-75553, and Japanese Patent No. 2502998.
No. 3,053,231, JP-A-63-17617
No. 3, Japanese Patent No. 2604367, and Japanese Patent Laid-Open No. 7-27678.
7, JP-A-9-207425, JP-A-11-589.
41, JP-A-2000-135858, JP-A-2001
-205924, JP 2001-287444 A, JP 62-278080 A, JP 9-39373 A,
Japanese Patent No. 2750433, Japanese Patent Laid-Open No. 2000-158801
No. 2001-213045, 2001-3
28345, JP-A-8-324105, JP-A-11
Examples thereof include those described in No. 348417 and the like. In addition, examples of water-soluble resins other than polyvinyl alcohol resins include compounds described in JP-A No. 11-165461, "0011" to "0014". These water-soluble resins may be used alone or in combination of two or more.

The content of the water-soluble resin of the present invention is preferably 9 to 40% by mass, and more preferably 12 to 33% by mass, based on the total mass of the solid content of the colorant receiving layer.

Mainly constituting the colorant receiving layer of the present invention,
The fine particles and the water-soluble resin may each be a single material, or may be a mixed system of a plurality of materials. still,
From the viewpoint of maintaining transparency, the type of water-soluble resin combined with fine particles, particularly silica fine particles, is important. When the vapor phase silica is used, the water-soluble resin is preferably a polyvinyl alcohol-based resin, of which a polyvinyl alcohol-based resin having a saponification degree of 70 to 100% is more preferable, and a saponification degree of 80 to 99.5. % Polyvinyl alcohol resin is particularly preferred.

The polyvinyl alcohol-based resin has a hydroxyl group in its structural unit. Since the hydroxyl group and a surface silanol group of the silica fine particles form a hydrogen bond, the secondary particles of the silica fine particles are used as a network chain unit. It becomes easy to form a three-dimensional network structure. It is considered that the formation of this three-dimensional network structure forms a colorant receiving layer having a porous structure with high porosity and sufficient strength. In ink jet recording, the porous coloring material-receiving layer obtained as described above rapidly absorbs ink by a capillary phenomenon,
It is possible to form dots having good circularity without causing ink bleeding.

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-based resin are used in combination, the content of the polyvinyl alcohol-based 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 Fine Particles and Water-Soluble Resin> Mass ratio of fine particles (x) and water-soluble resin (y) [PB ratio (x
/ Y)] has a great influence on the film structure and film strength of the colorant receiving layer. That is, when 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.

The coloring material-receptive layer of the present invention has the above-mentioned mass content ratio [PB ratio (x / y)] which prevents film strength from being lowered and cracks during drying due to the PB ratio being too large. In addition, when the PB ratio is too small, the voids are likely to be clogged with the resin, and the ink absorbency is prevented from being lowered due to the reduction of the void ratio.
5-10 are preferable.

Since the recording sheet may be stressed when passing through the transport system of the ink jet printer, the coloring material receiving layer must have sufficient film strength. Further, in the case of cutting into a sheet shape, it is necessary that the coloring material receiving layer has sufficient film strength in order to prevent cracking or peeling of the coloring material receiving layer. Taking these cases into consideration, 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, the gas phase method silica fine particles having an average primary particle diameter of 20 nm or less and the water-soluble resin are mixed in a mass ratio (x /
y) When a coating solution completely dispersed in an aqueous solution in 2 to 5 is coated on a support and the coating layer is dried, a three-dimensional network structure having secondary particles of silica fine particles as a network chain is formed, The average pore diameter is 25 nm or less, the porosity is 50 to 80%,
Pore specific volume 0.5ml / g or more, specific surface area 100m
It is possible to easily form a light-transmitting porous film having a weight ratio of ² / g or more.

(Crosslinking Agent) In the colorant receiving layer of the ink jet recording sheet of the present invention, the coating layer containing the fine particles and the water-soluble resin further contains a crosslinking agent capable of crosslinking the water-soluble resin. A preferred embodiment is a porous layer that is cured by a crosslinking reaction with a water-soluble resin.

Boron compounds are preferred for crosslinking the above water-soluble resins, especially polyvinyl alcohol. Examples of the boron compound include borax, boric acid, borate (for example,
Orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , La
_{BO 3, Mg 3 (BO 3} ) 2, Co 3 (BO 3) 2, two borates _{(e.g., Mg 2 B 2 O 5,} Co 2 B 2 O 5), metaborate salts (e.g., LiBO _2, Ca (BO ₂ ) ₂ , NaBO ₂ , KB
O ₂ ), tetraborate (eg, Na ₂ B ₄ O ₇ · 10H
₂ O), pentaborate (eg KB ₅ O ₈ .4H ₂ O, Ca _{2
B 6 O 1 1 · 7H 2} O, can be cited CsB ₅ O ₅₎ or the like. Among them, borax, boric acid, and borate are preferable, and boric acid is particularly preferable, because a crosslinking reaction can be rapidly caused.

As the crosslinking agent for the water-soluble resin, the following compounds other than the boron compound can be used. 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-triazine, 2,4-dichloro-6-S-
Active halogen compounds such as triazine / sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N'-ethylenebis (vinylsulfonylacetamide), 1,3,5-triacryloyl-hexahydro Active vinyl compounds such as -S-triazine; N such as dimethylolurea and methyloldimethylhydantoin
A methylol compound; a melamine resin (eg methylol melamine, alkylated methylol melamine); an epoxy resin;

Isocyanate compounds such as 1,6-hexamethylene diisocyanate; US Pat. No. 301
Nos. 7280 and 2983611; aziridine compounds; carboximide compounds described in U.S. Pat. No. 3,100,704; epoxy compounds such as glycerol triglycidyl ether; 1,6-hexamethylene-N, N '. -Ethyleneimino compounds such as bisethyleneurea; halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; dioxane compounds such as 2,3-dihydroxydioxane; titanium lactate, aluminum sulfate, chromium alum, potassium Examples thereof include metal-containing compounds such as alum, zirconyl acetate and chromium acetate, polyamine compounds such as tetraethylenepentamine, hydrazide compounds such as adipic acid dihydrazide, and low molecular weight compounds or polymers containing two or more oxazoline groups. The above-mentioned crosslinking agents may be used alone or in combination of two or more.

Crosslinking and curing are carried out by adding a crosslinking agent to a coating solution containing fine particles, a water-soluble resin and the like (hereinafter sometimes referred to as "coating solution A") and / or a basic solution described below, and
(1) When the coating liquid is applied to form a coating layer,
Or (2) a basic solution having a pH of 8 or more (hereinafter, referred to as “coating layer”) at any time during the drying of the coating layer formed by coating the coating solution and before the coating layer shows the rate-decreasing drying. It is preferable to apply it to the coating layer). The cross-linking agent is preferably applied as described below using a boron compound as an example. That is, when the color material receiving layer is a layer obtained by crosslinking and curing the coating layer coated with the coating liquid (coating liquid A) containing the water-soluble resin containing fine particles and polyvinyl alcohol,
The cross-linking curing is (1) at the same time when the above-mentioned coating liquid is applied,
(2) A basic solution having a pH of 8 or more (coating solution B) during the dry coating of the coating layer formed by applying the coating solution and before the coating layer shows the rate-decreasing drying. Is applied to the coating layer. The boron compound as a crosslinking agent may be contained in either the coating liquid A or the coating liquid B, or may be contained in both the coating liquid A and the coating liquid B. The amount of the cross-linking agent used is 1 with respect to the water-soluble resin.
-50 mass% is preferred, and 5-40 mass% is more preferred.

(Mordant) In the present invention, a mordant is preferably contained in the colorant-receiving layer in order to improve the water resistance of the formed image and the bleeding resistance with time. As the mordant, the organic mordant is preferably the above-mentioned cationic polymer (cationic mordant) or inorganic mordant,
By allowing the mordant to be present in the colorant-receiving layer, it interacts with the liquid ink containing the anionic dye as a colorant to stabilize the colorant, thereby improving water resistance and bleeding resistance over time. The organic mordant and the inorganic mordant may be used alone, respectively, or the organic mordant and the inorganic mordant may be used in combination.

The mordant is added to the coating liquid containing the fine particles and the water-soluble resin (coating liquid A) or, if there is a fear of aggregation with the fine particles, contained in the coating liquid B for coating.

An inorganic mordant may be used as the mordant of the present invention, and examples of the inorganic mordant 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, cerium, praseodymium, neodymium, samarium, europium, gadolinium, dislopro Mention may be made of salts or complexes of metals selected from sium, 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. , Cupric chloride, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate,
Nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel ammonium sulfate hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum alum, basic polyaluminum hydroxide, aluminum sulfite, aluminum thiosulfate, Polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate, ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, zinc phenolsulfonate, odor Zinc oxide, zinc chloride,
Zinc nitrate hexahydrate, zinc sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate,
Titanium lactate, zirconium acetylacetonate, 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 Hydrate, magnesium citrate 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, germanium nitrate, strontium nitrate, yttrium acetate, yttrium chloride, Yttrium nitrate, indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanum acetate, lanthanum benzoate, cerium chloride, cerium sulfate,
Examples thereof include cerium octylate, praseodymium nitrate, neodymium nitrate, samarium nitrate, europium nitrate, gadolinium nitrate, dysprosium nitrate, erbium nitrate, ytterbium nitrate, hafnium chloride and bismuth nitrate.

As the inorganic mordant of the present invention, an aluminum-containing compound, a titanium-containing compound, a zirconium-containing compound and a metal compound (salt or complex) of Group IIIB series of the Periodic Table of the Elements are preferable. Mordant amount contained in the colorant 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 Components) The ink jet recording sheet of the present invention may further contain various known additives such as an acid, an ultraviolet absorber, an antioxidant, a fluorescent brightener, a monomer and a polymerization initiator, if necessary. Agent, polymerization inhibitor, anti-bleeding agent,
An antiseptic, a viscosity stabilizer, a defoaming agent, a surfactant, an antistatic agent, a matting agent, an anti-curl agent, a water resistant agent and the like can be contained.

In the present invention, the coloring material receiving layer may contain an acid. By adding an acid, the surface pH of the colorant receiving layer is adjusted to 3 to 8, preferably 5 to 7.5. This is preferable because the yellowing resistance of the white background portion is improved. The surface pH is measured by the Japan Pulp and Paper Technology Association (J. TAPP
In the measurement of the surface PH defined in I), the measurement is performed by the A method (coating method). For example, the measurement can be carried out using a paper surface PH measurement set “type MPC” manufactured by Kyoritsu Riken Kagaku Kenkyusho, which corresponds 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 and phthalic acid. , Isophthalic acid, glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, salicylic acid, salicylic acid metal salt (Zn, Al, C
a, salts such as Mg), methanesulfonic acid, itaconic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic 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-resorcinic acid, β-resorcinic acid, γ-resorcinic acid, gallic acid, phloroglysin, sulfosalicylic acid, ascorbic acid, erythorbic acid, bisphenolic acid, hydrochloric acid, nitric acid , Sulfuric acid, phosphoric acid,
Examples thereof include polyphosphoric acid, boric acid, and boronic acid. The addition amount of these acids may be determined so that the surface PH of the color material receiving layer becomes 3 to 8. The above-mentioned acids are metal salts (for example, sodium, potassium, calcium, cesium, zinc, copper,
When used in the form of iron, aluminum, zirconium, lanthanum, yttrium, magnesium, strontium, cerium, etc.) or an amine salt (eg, ammonia, triethylamine, tributylamine, piperazine, 2-methylpiperazine, polyallylamine, etc.) Good.

In the present invention, it is preferable that the colorant receiving layer contains a preservative improving agent such as an ultraviolet absorber, an antioxidant and a bleeding inhibitor. As these ultraviolet absorbers, antioxidants, and anti-bleeding agents, 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 bond, bisphenol compounds, O-, N-
And an S-benzyl compound, a hydroxybenzyl compound,
Triazine compound, phosphonate compound, acylaminophenol compound, ester compound, amide compound, ascorbic acid, amine antioxidant, 2- (2-hydroxyphenyl) benzotriazole compound, 2-hydroxybenzophenone compound, acrylate, water-soluble or hydrophobic Metal salt, organometallic compound, metal complex, hindered amine compound (including TEMPO compound), 2- (2-
Hydroxyphenyl) 1,3,5-triazine compound, metal deactivator, phosphite compound, phosphonite compound, hydroxyamine compound, nitrone compound,
Peroxide scavenger, polyamide stabilizer, polyether compound, basic co-stabilizer, nucleating agent, benzofuranone compound, indolinone compound, phosphine compound, polyamine compound, thiourea compound, urea compound, hydrazito compound, amidine compound, sugar compound, Examples thereof include hydroxybenzoic acid compounds, dihydroxybenzoic acid compounds and trihydroxybenzoic acid compounds.

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

Specific examples of compounds include Japanese Patent Application No. 2002
-13005, JP-A-10-182621, JP-A-2
No. 001-260519, Japanese Patent Publication No. 4-34953, Japanese Patent Publication No. 4-34513, JP-A No. 11-170686,
JP-B-4-34512, EP1138509, JP-A-60-67190, JP-A-7-276808, JP-A-2001-94829, and JP-A-47-10537.
No. 58-111942, No. 58-212844.
59, 19945, 59-46646, 59-109055, 63-53544, 36-66466, 42-26187, 48-.
30492, 48-31255, 48-415
No. 72, No. 48-54965, No. 50-10726.
U.S. Pat. Nos. 2,719,086 and 3,707,
375, 3,754,919, 4,220,7
No. 11,

Japanese Examined Patent Publication Nos. 45-4699 and 54-532
No. 4, European Published Patent Nos. 223739, 309.
No. 401, No. 309402, No. 310551, No. 310552, No. 459416, German Published Patent No. 3435443, JP-A-54-48535, No. 6
0-107384, 60-107383, 60
-125470, 60-125471, 60-
125472, 60-287485, 60-2
87486, 60-287487, 60-28
7488, 61-160287, 61-185.
No. 483, No. 61-211079, No. 62-1466.
No. 78, No. 62-146680, No. 62-14667.
No. 9, No. 62-282885, No. 62-262047.
No. 63-051174, No. 63-89877,
63-88380, 66-88381, 63
-113536,

63-163351 and 63-203.
372, 63-224989, 63-2512
No. 82, No. 63-267594, No. 63-18248.
4, JP-A-1-239382, and JP-A-2-2626.
No. 54, No. 2-71262, No. 3-121449,
No. 4-291685, No. 4-291688, No. 5-
61166, 5-1149449, 5-1886
No. 87, No. 5-188686, No. 5-110490
No. 5-1108437, No. 5-170361,
Examples thereof include those described in Japanese Patent Publications No. 48-43295, No. 48-33212, U.S. Pat. Nos. 4,814,262 and 4,980,275.

The other components may be used alone or in combination of two or more. These other components may be added after being made water-soluble, dispersed, polymer-dispersed, emulsified, oil-dropped, or encapsulated in microcapsules. In the inkjet recording sheet of the present invention,
The addition amount of the above-mentioned other components is 0.01 to 10 g.
/ M ² is preferred.

The surface of the inorganic fine particles may be treated with a silane coupling agent for the purpose of improving the dispersibility of the inorganic fine particles. Examples of the silane coupling agent include an organic functional group (for example, vinyl group, amino group (primary to tertiary amino group, quaternary ammonium salt group), epoxy group, mercapto, etc., in addition to the site for coupling treatment. Group, chloro group,
Those having an alkyl group, a phenyl group, an ester group, etc.) are preferable.

In the present invention, the coating liquid for the colorant receiving layer (coating liquid A) preferably contains a surfactant.
As the surfactant, any of cationic, anionic, nonionic, amphoteric, fluorine-based, and silicon-based surfactants can be used. Examples of the nonionic surfactants include polyoxyalkylene alkyl ethers and polyoxyalkylene alkylphenyl ethers (for example, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxy). Ethylene nonyl phenyl ether, etc.), oxyethylene / oxypropylene block copolymer, sorbitan fatty acid esters (eg, sorbitan monolaurate, sorbitan monooleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (eg, polyoxyethylene) Sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan Rioreto etc.), polyoxyethylene sorbitol fatty acid esters (e.g., polyoxyethylene sorbit tetraoleate and the like), glycerol fatty acid esters (e.g.,
Glycerol monooleate etc.), polyoxyethylene glycerin fatty acid esters (polyoxyethylene glycerin monostearate, polyoxyethylene glycerin monooleate etc.), polyoxyethylene fatty acid esters (polyethylene glycol monolaurate, polyethylene glycol monooleate etc.) ), Polyoxyethylene alkylamines, acetylene glycols (eg,
2,4,7,9-Tetramethyl-5-decyne-4,7-
Diols, ethylene oxide adducts and propylene oxide adducts of the diols), and the like, among which polyoxyalkylene alkyl ethers are preferable. The nonionic surfactant can be used in the coating liquid A and the coating liquid B. Further, the nonionic surfactants may be used alone or in combination of two or more kinds.

Examples of the amphoteric surfactants include amino acid type, carboxyammonium betaine type, sulfolammonium betaine type, ammonium sulfate ester betaine type, imidazolium betaine type and the like. For example, US Pat. No. 3,843,368. Specification, JP-A-5
9-49535, 63-236546,
What is described in Unexamined-Japanese-Patent No. 5-303205, 8-262742, 10-282619 etc. can be used conveniently. As the amphoteric surfactant,
Amino acid-type amphoteric surfactants are preferable, and the amino acid-type amphoteric surfactants are, for example, derivatized from amino acids (glycine, glutamic acid, histidic acid, etc.) as described in JP-A-5-303205. Examples thereof include N-aminoacyl acid having a long-chain acyl group introduced and salts thereof. The amphoteric surfactants may be used alone or in combination of two or more.

Examples of the anionic surfactant include fatty acid salts (for example, sodium stearate, potassium oleate),
Alkyl sulfate ester salts (eg sodium lauryl sulfate, triethanolamine lauryl sulfate), sulfonates (eg sodium dodecylbenzenesulfonate),
Examples thereof include alkyl sulfosuccinates (for example, sodium dioctyl sulfosuccinate), alkyl diphenyl ether disulfonates, alkyl phosphates and the like. Examples of the cationic surfactant include alkylamine salts,
Examples thereof include primary ammonium salts, pyridinium salts and imidazolium salts.

Examples of the above-mentioned fluorine-containing surfactants include compounds that are derived via 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 phosphates.

As the silicone-based surfactant, an organic group-modified silicone oil is preferable, which has a structure in which the side chain of a siloxane structure is modified with an organic group, both ends are modified, and one end is modified. It can have a structure. 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 0.001 to 2 with respect to the coating liquid for the colorant receiving layer (coating liquid A).
0% is preferable, and 0.01 to 1.0% is more preferable.
When two or more coating liquids for the color material receiving layer are used for coating, it is preferable to add a surfactant to each coating liquid.

In the present invention, the colorant receiving layer preferably contains a high boiling organic solvent for preventing curling. The high-boiling point organic solvent is an organic compound having a boiling point of 150 ° C. or higher under normal pressure and is a water-soluble or hydrophobic compound. These may be liquid or solid at room temperature, and may be low molecular weight or high molecular weight.
Specifically, aromatic carboxylic acid esters (eg, dibutyl phthalate, diphenyl phthalate, phenyl benzoate, etc.), aliphatic carboxylic acid esters (eg, dioctyl adipate, dibutyl sebacate, methyl stearate, dibutyl maleate) , Dibutyl fumarate, acetyl triethyl citrate, etc.), phosphates (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, glycerin, diethylene glycol monobutyl ether (DE
GMBE), triethylene glycol monobutyl ether, glycerin monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,
2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, triethanolamine,
Polyethylene glycol etc.), vegetable oil (eg soybean oil, sunflower oil etc.) and higher aliphatic carboxylic acid (eg linoleic acid, oleic acid etc.) and the like.

(Support) As the support of the present invention, 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 the most of the transparency of the colorant receiving layer, it is preferable to use a transparent support or a highly glossy opaque support.

As a material that can be used for the transparent support, a material that is transparent and has the property of withstanding radiant heat when used in an OHP or backlight display is preferable. Examples of the material include polyesters such as polyethylene terephthalate (PET); polysulfone,
Examples thereof include polyphenylene oxide, polyimide, polycarbonate and polyamide. Among them, polyesters are preferable, and polyethylene terephthalate is particularly preferable. The thickness of the transparent support is not particularly limited, but is preferably 50 to 200 μm from the viewpoint of easy handling.

As the highly glossy opaque support, one having a glossiness of 40% or more on the surface on which the colorant receiving layer is provided is preferable. The glossiness is JIS P-814.
It is a value obtained according to the method described in 2 (75-degree specular gloss test method for paper and paperboard). Specific examples include the following supports.

For example, high gloss paper supports such as art papers, coated papers, cast coated papers, and baryta papers used for silver salt photographic supports; polyesters such as polyethylene terephthalate (PET); nitrocellulose. Cellulose esters such as cellulose acetate and cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate and polyamide are made opaque by containing a white pigment and the like (may be subjected to surface calendering treatment). High-gloss film; or a high-gloss film containing the above various paper supports, the above-mentioned transparent supports or white pigments, etc., provided with a polyolefin coating layer containing or not containing a white pigment. And a support or the like. A white pigment-containing expanded polyester film (for example, expanded PET in which polyolefin fine particles are contained and voids are formed by stretching) can also be preferably mentioned. Further, resin coated paper used for silver salt photographic printing paper is also suitable.

The thickness of the opaque support is not particularly limited, but is preferably 50 to 300 μm from the viewpoint of handleability.

The surface of the support may be subjected to a corona discharge treatment, a glow discharge treatment, a flame treatment, an ultraviolet irradiation treatment or the like in order to improve the wetting property and the adhesiveness.

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, synthetic paper such as polypropylene, or synthetic fiber such as nylon or polyester is used in addition to wood pulp. Examples of the wood pulp include LBKP, LBSP, NBKP, NBS
Any of P, LDP, NDP, LUKP and NUKP can be used, but LBKP and NBS with a large amount of short fibers
It is preferable to use more P, LBSP, NDP, and LDP. However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

As the above pulp, a chemical pulp containing few impurities (sulfate pulp or sulfite pulp) is preferably used,
Pulp that has been bleached to improve its whiteness 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 strengthening agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, A water retention agent such as polyethylene glycol, a dispersant, and a softening agent such as quaternary ammonium can be appropriately added.

The freeness of the pulp used for papermaking is
According to CSF regulations, 200 to 500 ml is preferable, and
The fiber length after beating is preferably 30 to 70% of the sum of the 24% mesh residual mass% and the 42 mesh residual mass% defined by JIS P-8207. The mass% of the 4-mesh residue is preferably 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 papermaking stage or after the papermaking. The base paper density is 0.7 to 1.2 g / m ² (J
ISP-8118) is common. Furthermore, the stiffness of the base paper is 2 under the conditions specified in JIS P-8143.
0 to 200 g is preferable.

A surface sizing agent may be applied to the surface of the base paper, and as the surface sizing agent, the same sizing agent as that which can be added to the base paper can be used. The pH of the base paper is JI
It is preferably 5 to 9 when measured by the hot water extraction method specified in SP-8113.

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

In particular, the polyethylene layer on the side for forming the colorant receiving layer contains rutile or anatase type titanium oxide, an optical brightener, and ultramarine blue added to polyethylene, as is widely used in photographic printing paper. However, those having improved opacity, whiteness and hue are preferred. Here, the content of titanium oxide is generally 3 to 3 with respect to polyethylene.
20 mass% is preferable and 4-13 mass% is more preferable. The thickness of the polyethylene layer is not particularly limited, but 10 to 50 μm is suitable for both the front and back layers. Further, an undercoat layer may be provided on the polyethylene layer in order to impart adhesion to the coloring material receiving layer. As the undercoat layer, aqueous polyester, gelatin and PVA are preferable. Further, the thickness of the undercoat layer is preferably 0.01 to 5 μm.

The polyethylene-coated paper can be used as a glossy paper, or when a polyethylene is melt-extruded on the surface of a base paper for coating, a so-called patterning treatment is performed to obtain a matte surface or a matte surface obtained by ordinary photographic printing paper. It is also possible to use those having a silk surface.

A back coat layer may be provided on the support, and the components that can be added to this back coat layer are:
Examples include white pigments, aqueous binders, and other components. Examples of the white pigment contained in the back coat 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, pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloisite, magnesium carbonate, white inorganic pigments such as magnesium hydroxide, styrene plastic pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin, melamine Examples include organic pigments such as 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,
Examples thereof include water-soluble polymers such as cationized starch, casein, gelatin, carboxymethyl cellulose, hydroxyethyl cellulose and polyvinylpyrrolidone, and water-dispersible polymers such as styrene butadiene latex and acrylic emulsion. Examples of other components contained in the back coat layer include a defoaming agent, a defoaming agent, a dye, a fluorescent brightening agent, a preservative, and a water resistance agent.

(Preparation of Inkjet Recording Sheet) The coloring material receiving layer of the inkjet recording sheet of the present invention is prepared, for example, by applying a coating liquid A containing at least fine particles and a water-soluble resin on the surface of a support, and (1) Either at the same time as the coating, or (2) during the drying of the coating layer formed by the coating and before the coating layer exhibits a rate of reduction drying, p
After applying the coating liquid B having H of 8 or more, the coating layer to which the coating liquid B is applied is crosslinked and cured (Wet-on-We).
It is preferably formed by the t method). Here, the crosslinking agent capable of crosslinking the water-soluble resin is preferably contained in at least one or both of the coating liquid A and the coating liquid B. It is preferable to provide the color material-receptive layer cross-linked and cured in this way from the viewpoints of ink absorbency and prevention of film cracking.

When the mordant is added to the coating liquid B, a large amount of the mordant is present near the surface of the colorant-receiving layer, so that the colorant of the ink jet is sufficiently mordant and the water resistance of characters and images after printing is improved. preferable. A part of the mordant may be contained in the coating liquid A, and in this case, the mordants of the coating liquid A and the coating liquid B may be the same or different.

In the present invention, the coating liquid for the colorant receiving layer (coating liquid A) containing at least fine particles (for example, vapor phase silica) and a water-soluble resin (for example, polyvinyl alcohol) is as follows. Can be prepared. That is, fine particles such as vapor phase silica and a cationic polymer dispersant are added to water (for example, silica fine particles in water are 10 to 20% by mass), and a high-speed rotating wet colloid mill (for example, manufactured by M Technique Co., Ltd.) is used. "Clearmix") of 1), for example, for 20 minutes (preferably 10 to 30 minutes) under the condition of high-speed rotation of 10,000 rpm (preferably 5000 to 20000 rpm) to obtain a dispersion liquid of the present invention, Cross-linking agent (boron compound, etc.
May be added to coating liquid A), polyvinyl alcohol (P
It can be prepared by adding an aqueous solution of a water-soluble resin such as VA) (for example, so that PVA has a mass of about 1/3 of the vapor grown silica) and dispersing under the same rotation conditions as described above. . The obtained coating liquid is in a uniform sol state, and a porous coloring material-receptive layer having a three-dimensional network structure can be formed by coating it on a support by the following coating method and drying it. .

As the solvent in each step, water, an organic solvent, or a mixed solvent thereof can be used.
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, toluene and the like. To be

The coating of the coating solution for the color material receiving layer is carried out, for example, by
It can be performed 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, and a bar coater.

The coating liquid B is applied to the coating layer at the same time as or after the application of the coating liquid for the colorant receiving layer (coating liquid A). It may be applied before the specific drying rate is exhibited. That is, after being coated with the coating liquid for the colorant receiving layer (coating liquid A), it is suitably manufactured by introducing a mordant while the coating layer exhibits a constant rate of drying.

Here, the above "before the coating layer starts to exhibit the rate of decrease in drying rate" usually refers to a process for a few minutes immediately after the coating liquid for the color material receiving layer is applied, and during this period, the coating is performed. The phenomenon of "constant rate of drying" in which the content of the solvent (dispersion medium) in the applied coating layer decreases in proportion to time is shown. Regarding the time indicating this "constant rate of drying", see, for example, Chemical Engineering Handbook (pages 707 to 712, published by Maruzen Co., Ltd., Showa 5).
October 25, 5).

As described above, after the coating liquid A is coated, the coating layer is dried until it exhibits a rate of reduction drying, and this drying is generally at 40 to 180 ° C. for 0.5 to 10 minutes (preferably Is performed for 0.5 to 5 minutes). The drying time naturally depends on the coating amount, but the above range is usually appropriate.

As the method for applying before the first coating layer shows the rate of decrease in drying rate, the coating solution B is further coated on the coating layer, the method of spraying by a method such as spraying, the coating method. Examples include a method of immersing the support having the coating layer formed therein in the liquid B.

In the above method, as the coating method for coating the coating liquid B, for example, a curtain flow coater
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 can be used. However, it is preferable to use a method, such as an extrusion die coater, a curtain flow coater, or a bar coater, in which the coater does not directly contact the already formed first coating layer.

After applying the coating liquid B, it is generally 40 to 180.
Drying and curing are carried out by heating at 0 ° C. for 0.5 to 30 minutes. Above all, it is preferable to heat at 40 to 150 ° C. for 1 to 20 minutes.

When the coating liquid B is applied simultaneously with the coating of the colorant-receptive layer coating liquid (coating liquid A), the coating liquid A and the coating liquid B are contacted with the support. A colorant receiving layer can be formed by simultaneous coating (multi-layer coating) on a support and subsequent drying and curing.

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

When the above simultaneous coating (multilayer coating) is carried out, for example, by an extrusion die coater,
The two types of coating liquids discharged at the same time are layered in the vicinity of the discharge port of the extrusion die coater, that is, before being transferred onto the support, and in that state, they are layered on the support. The two layers of coating liquid that have been overlaid before coating tend to undergo a cross-linking reaction at the interface between the two liquids when they are transferred to the support. As a result, the viscosity tends to increase, which may hinder the coating operation. Therefore, when simultaneously coating as described above, the barrier layer liquid (intermediate layer liquid) is applied together with the coating of the coloring material receiving layer coating liquid (coating liquid A) and the mordant solution (coating liquid B).
It is preferable that the two layers are intervened between the above two liquids and simultaneous triple layer coating is performed.

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

After the color material receiving layer is formed on the support, the surface of the color material receiving layer is smoothed by applying a calendering treatment under heat and pressure through a roll nip using, for example, a super calender or a gloss calender. It is possible to improve properties, glossiness, transparency and coating film strength. However, the calendering process may cause a decrease in the porosity (that is, the ink absorbency may decrease), and therefore, it is necessary to set conditions under which the decrease in the porosity is small.

The roll temperature for calendering treatment is preferably 30 to 150 ° C., and 40 to 100 ° C.
C is more preferred. Further, the linear pressure between the rolls during the calendar treatment is preferably 50 to 400 kg / cm,
100 to 200 kg / cm is more preferable.

In the case of ink jet recording, the layer thickness of the color material receiving layer needs to be determined in relation to the porosity in the layer, because it is necessary to have an absorption capacity enough to absorb all the droplets. is there. For example, if the ink amount is 8 nL / mm ²
If the porosity is 60%, the layer thickness is about 15 μm.
The above film is required. Considering this point, in the case of inkjet recording, the layer thickness of the colorant receiving layer is 1
0 to 50 μm is preferable.

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

The colorant-receiving layer preferably has excellent transparency. As a guideline, the haze value when the colorant-receiving layer is formed on a transparent film support is 30.
% Or less, and more preferably 20% or less. The haze value is a haze meter (HG
M-2DP: It can be measured using Suga Test Instruments Co., Ltd.

A polymer fine particle dispersion may be added to the constituent layers of the ink jet recording sheet of the present invention (for example, a color material receiving layer or a back layer). This polymer fine particle dispersion is used for the purpose of improving physical properties of the film such as dimensional stabilization, curl prevention, adhesion prevention, and film cracking prevention. For the polymer fine particle dispersion, see Japanese Patent Laid-Open No.
2-245258, 62-1316648, 6
It is described in each publication of 2-110066. When a polymer fine particle dispersion having a low glass transition temperature (40 ° C. or lower) is added to the layer containing the mordant, cracking or curling of the layer can be prevented. Further, even if a polymer fine particle dispersion having a high glass transition temperature is added to the back layer,
Curling can be prevented.

[0116]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. In addition, "parts" and "%" in Examples represent "parts by mass" and "mass%" unless otherwise specified, and "average molecular weight".
"Polymerization degree" means "mass average molecular weight" and "mass average polymerization degree".

Preparation of Silica Dispersion Liquid (Preparation of Silica Dispersion Liquid 1) A pre-dispersion liquid having the following composition was used with KDL-PILOT manufactured by Shinmaru Enterprises Co., Ltd., 1.5 mm bead packing rate 80%, peripheral speed Silica dispersion liquid 1 was prepared at 14 m / sec. Silica fine particles (average particle diameter 14 nm) 25.2 parts (specific surface area by BET method: 300 m ² / g; Tokuyama Co., Ltd., QS-30) Ion-exchanged water 141 parts Polydiallyldimethylammonium chloride 1.8 parts (molecular weight 35,000, sulfate ion concentration 0.3 mass%)

(Preparation of Silica Dispersion Liquid 2) Polydiallyldimethylammonium chloride was added in the same amount with a molecular weight of 6600.
0, except that the sulfate ion concentration was changed to 0.5% by mass,
Silica Dispersion Liquid 2 in the same manner as (Preparation of Silica Dispersion Liquid 1)
It was created.

(Preparation of Silica Dispersion Liquid 3) 1.8 parts of polydiallyldimethylammonium chloride was added to a polymer having a molecular weight of 1400.
A silica dispersion liquid 3 was prepared in the same manner as in (Preparation of silica dispersion liquid 1) except that 0.98 parts having a sulfate ion concentration of 0.2 mass% were used.

(Preparation of Silica Dispersion Liquid 4) Polydiallyldimethylammonium chloride was added in the same amount with a molecular weight of 1900.
0, except that the sulfate ion concentration is 1.6% by mass,
Silica dispersion 4 in the same manner as (Preparation of silica dispersion 1)
It was created.

The liquid stability of the above silica dispersion was evaluated. The results are shown in Table 1.

[0122]

[Table 1]

From Table 1, those having a molecular weight of more than 60,000 are
It can be seen that the viscosity increases with time, and even if the molecular weight is 60,000 or less, a solution having a sulfate ion concentration of more than 1.5% by mass becomes a high viscosity liquid.

Preparation of ink jet recording sheet (preparation of support) Wood pulp consisting of 100 parts of LBKP was beaten to a Canadian freeness of 300 ml with a double disc refiner to give 0.5 part of epoxidized behenic acid amide and 1.0 part of anionic polyacrylamide. 0.1 parts of polyamide polyamine epichlorohydrin and 0.5 parts of cationic polyacrylamide were added at an absolutely dry mass ratio to the pulp, and weighed with a Fourdrinier paper machine 1
A 70 g / m ² base paper was made into paper.

In order to adjust the surface size of the above-mentioned base paper, 0.04% of a fluorescent whitening agent (“Whitex BB” manufactured by Sumitomo Chemical Co., Ltd.) was added to a 4% aqueous solution of polyvinyl alcohol.
The base paper was added and impregnated into the above-mentioned base paper so as to be 0.5 g / m ^{2 in} terms of absolute dry mass, dried and then calendered to obtain a base paper adjusted to a density of 1.05 g / cc. Obtained.

The wire surface (back surface) side of the obtained base paper was subjected to corona discharge treatment, and then high density polyethylene was coated to a thickness of 19 μm using a melt extruder, and a resin layer consisting of a matte surface was formed. Was formed (hereinafter, the resin layer surface is referred to as “rear surface”). The 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.) Snowtex O ") was dispersed in water at a mass ratio of 1: 2, and the resulting dispersion was applied so that the dry mass would be 0.2 g / m ² .

Further, after the corona discharge treatment was applied to the felt surface (front surface) side where the resin layer was not provided, anatase type titanium dioxide 10%, a trace amount of ultramarine blue, and an optical brightening agent 0.01% ( Polyethylene) and low density polyethylene with MFR (melt flow rate) 3.8 are extruded using a melt extruder to a thickness of 29 μm, and a high-gloss thermoplastic resin layer is provided on the surface side of the base paper. (Hereinafter, this high-gloss surface is referred to as "front surface") to form a support.

[Example 1] (Preparation of coating material A1 for colorant receiving layer) Silica dispersion 1
62.3 parts of 8% polyvinyl alcohol ("PVA124" manufactured by Kuraray Co., Ltd., saponification degree 98.5%, polymerization degree 24
00) 27.8 parts and a solution containing 0.4 parts of boric acid are added,
Further, stirring was performed with a dissolver at a rotation speed of 8000 rpm for 10 minutes, and 1.2 parts of polyoxyethylene lauryl ether (“Emulgen 109P” (10% aqueous solution, manufactured by Kao Corporation, HLB13.6) and ion-exchanged water 33.
Add a solution containing 4 parts, and add 1 at 2,000 rpm.
Stirring was performed for 0 minutes with a dissolver to prepare a coating material A for a color material receiving layer. The mass ratio (PB ratio = /) of the silica fine particles to the water-soluble resin was 4.5, and the pH of the coating material A for the colorant receiving layer was 3.5, indicating acidity.

[0129]   <Composition of coating liquid A1 for colorant receiving layer> Silica dispersion 1 62.3 parts Polystop 7300P (Hakuto Co., Ltd.) 0.06 copies Polyvinyl alcohol (water-soluble resin) 8% aqueous solution 27.8 parts   ("PVA124" manufactured by Kuraray Co., saponification degree 98.5%, polymerization degree 2400) Boric acid (crosslinking agent) 0.4 parts Polyoxyethylene lauryl ether (surfactant) 1.2 parts ("Emulgen 109P" (10% aqueous solution, manufactured by Kao Corporation, HLB value 13.6) Deionized water 33.4 parts

(Preparation of Inkjet Recording Sheet) After the front surface of the support was subjected to corona discharge treatment, the coating material A1 for the colorant receiving layer obtained as described above was applied to the front surface of the support. 2 using the Rouge die coater
A coating amount of 00 ml / m ² was applied (coating step), followed by drying with a hot air dryer at 80 ° C. (air velocity 3 to 8 m / sec) until the solid content concentration of the coating layer reached 20%. This coating layer exhibited a constant drying rate during this period. Immediately after that, it was dipped in a mordant solution B1 having the following composition for 30 seconds to form 2 on the coating layer.
0 g / m ² (step of applying mordant solution),
Further, it was dried at 80 ° C. for 10 minutes (drying step). As a result, an inkjet recording sheet (1) of the present invention provided with a coloring material receiving layer having a dry film thickness of 32 μm was produced.

[0131]   <Composition of mordant coating liquid B1> Boric acid (crosslinking agent) 0.65 parts Polyallylamine "PAA-10C" 10% aqueous solution 25 parts   (Mordant, manufactured by Nittobo Co., Ltd.) 2-Methylpiperazine (Koei Chemical Industry Co., Ltd.) 2.5 parts Deionized water 59.7 parts Ammonium chloride (surface pH adjuster) 0.8 parts Polyoxyethylene lauryl ether (surfactant) 10 parts   ("Emulgen 109P" manufactured by Kao Corporation, 2% aqueous solution, HLB value 13.6) MegaFac “F1405” 10% aqueous solution 2.0 parts   (Fluorine-based surfactant manufactured by Dainippon Ink and Chemicals, Inc.)

[Example 2] An ink jet recording sheet of Example 2 was prepared according to Example 1 except that the silica dispersion liquid 1 was changed to the silica dispersion liquid 3 in Example 1.

[Comparative Example 1] In the same manner as in Example 1, except that the coloring material receiving layer coating liquid A1 was changed to the coloring material receiving layer coating liquid A2.
An ink jet recording sheet of Comparative Example 1 was prepared according to Example 1.

(Preparation of Coating Material A2 for Coloring Material Receiving Layer) KD-P manufactured by Shinmaru Enterprises Co., Ltd. was used by mixing gas phase method silica fine particles having the following composition, ion-exchanged water and ammonia water. After dispersing at a rotation speed of 10,000 rpm for 20 minutes, a solution containing the following polyvinyl alcohol, polyoxyethylene lauryl ether and ion-exchanged water is added, and the dispersion is performed again at a rotation speed of 10,000 rpm for 20 minutes. A coating liquid A2 for the colorant receiving layer was prepared. Mass ratio of fine silica particles and water-soluble resin (PB ratio =
/) Is 4.5, the pH of the coating material A for the colorant receiving layer
Showed acidity at 3.5.

<Composition of Colorant Receptive Layer Coating Liquid A2> Silica Fine Particles ... 25.2 parts (specific surface area by BET method: 300 m ² / g; Tokuyama Corp., QS-30) Ion-exchanged water・ ・ ・ 141 parts 1N ammonia water ・ ・ ・ 9 parts Polyvinyl alcohol 7% aqueous solution ・ ・ ・ 79.9 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree 98.5%, polymerization degree 2400) Polyoxyethylene Lauryl ether (surfactant) 9.8 parts ("Emulgen 109P" manufactured by Kao Corporation, 2% aqueous solution, HLB value 13.6)

Comparative Example 2 Example 1 was repeated except that the silica dispersion 1 was changed to the following silica dispersion 5 in Example 1.
An ink jet recording sheet of Comparative Example 2 was prepared according to the above. (Silica dispersion liquid 5) Silica fine particles ... 25.2 parts (specific surface area by BET method: 300 m ² / g; manufactured by Tokuyama Corp., QS-30)) Ion-exchanged water ... 136.2 parts Polyamidine ... 5.6 parts (SC700 modified, Hymo Co., Ltd., molecular weight 7,000, solid content concentration: 30%) (Evaluation test) For each of the inkjet recording sheets obtained above, the following evaluation test Was done. The test results are shown in Table 2.

(1) Gloss degree Digital variable angle gloss meter (UGA-5D, Suga Test Instruments Co., Ltd.)
The measurement was performed at an incident angle of 60 degrees with a measurement hole of 8 mm).

(2) Ink Absorption Rate Using an ink jet printer (PM-900C, manufactured by Seiko Epson Corp.), Y (yellow), M (magenta), C (cyan), and K (K) inks were formed on the ink jet recording sheet.
Solid images of (black), B (blue), G (green) and R (red) are printed, and immediately (after about 10 seconds), the paper is contact-pressed on the image to transfer the ink to the paper. The presence or absence of each of these was evaluated according to the following criteria. [Standard] AA: Ink transfer onto paper was not observed at all. It shows that the ink absorption rate is good. CC: Partial transfer of the ink onto the paper was observed.

(3) Water resistance Using the same printer as in (2), the same printing pattern was formed on an ink jet recording sheet, and after leaving for 3 hours,
Immerse in water for 1 minute, visually observe the flow of ink,
It evaluated as follows. AA: Dye did not flow at all BB: Part of the dye flowed and the color density became low CC: Dye flowed almost completely

(4) Blurring over time Using the same printer and ink as in (2) above, a grid-like linear pattern (line width 0.28 mm) in which magenta ink and black ink are placed side by side on an ink jet recording sheet. Was printed, and the visual density was measured by X-light 310TR (manufactured by X-light). Furthermore, after leaving for 3 hours after printing, 40 ° C, relative humidity 90%
After being stored in the constant temperature and humidity chamber for 1 day, the visual density was measured again and evaluated by the density difference (ΔOD). The smaller the value of the density difference (ΔOD), the more the generation of bleeding with time is suppressed.

(5) Printing Density Using an inkjet printer (PM-900C, manufactured by Seiko Epson Corp.), Y (yellow), M (magenta), C (cyan) and K are printed on the inkjet recording sheet.
Solid images of (black), B (blue), G (green) and R (red) were printed, and the density of the K (black) part was measured with an X light thermometer.

[0142]

[Table 2]

From the results of Table 2 above, it was found that the ink jet recording sheet of the present invention is a recording sheet excellent in print density and gloss.

[0144]

INDUSTRIAL APPLICABILITY The ink jet recording sheet of the present invention, when printed with an ink jet printer, has a fast drying property, a high print density, and a glossy feeling similar to a silver salt photograph.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 7/12 C09D 201/00 201/00 B41J 3/04 101Y F term (reference) 2C056 EA04 FC06 2H086 BA15 BA33 BA35 BA37 BA41 BA46 4J002 AA03W AB02X AB03X AB04X AB05X BC11W BE02X BG08W BG13W BG13X BJ00W BJ00X CC183 CD003 CH02X DE096 DE106 DE136 DE146 DE236 EUDG07 EU207 207 EU207 207 EA27 ED 207 EU27 207 EA27 EA27 ED27 EA27 ED 207 EA027 DK27 ED027 DK27 ED27 EA27 ED27 ED027 DK027 4J037 AA18 AA25 CC11 EE28 4J038 CE021 HA216 HA446 PC10

Claims (8)

[Claims] 1. In a dispersion liquid of fine particles having an average primary particle diameter of 50 nm or less, the average molecular weight of the cationic polymer contained in the dispersion liquid is 60,000 or less, and the sulfate ion concentration is 1 with respect to the cationic polymer. Dispersion liquid characterized by being 0.5 mass% or less. 2. The dispersion according to claim 1, wherein the cationic polymer is a polydiallyldialkyl cationic polymer. 3. The dispersion according to claim 1, wherein the fine particles having an average primary particle diameter of 50 nm or less are one kind or two or more kinds selected from silica fine particles, colloidal silica, alumina fine particles and pseudo-boehmite. 4. An ink jet recording sheet having a coloring material receiving layer, wherein the coloring material receiving layer contains the dispersion according to claim 1, 2 or 3 and a water-soluble resin. Inkjet recording sheet. 5. The ink jet recording sheet according to claim 4, wherein the colorant receiving layer further contains a crosslinking agent capable of crosslinking a water-soluble resin. 6. The ink jet recording sheet according to claim 5, wherein the crosslinking agent is boric acid or a boron compound. 7. The coloring material receiving layer is a layer having a three-dimensional network structure having a porosity of 50 to 80%, and the mass content ratio [PB ratio (x) of fine particles (x) and water-soluble resin (y). / Y)] is 1.
The inkjet recording sheet according to claim 4, 5 or 6, which has a size of 5 to 10. 8. A coloring material-receiving layer is a layer obtained by crosslinking and curing a coating layer coated with a coating liquid containing at least fine particles and a water-soluble resin, the crosslinking and curing being performed by the coating liquid and / or the following basicity. When a cross-linking agent is added to the solution, and (1) the coating liquid is applied to form a coating layer, or (2) the coating layer formed by coating the coating liquid is being dried, The coating is performed by applying a basic solution having a pH of 8 or more to the coating layer at any time before the coating layer shows the rate-decreasing dryness. Inkjet recording sheet.