JP2003205674A - Ink jet recording sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having high glossiness on its recording surface, excellent in ink absorbability, capable of obtaining a high density image of high resolving power, capable of stably holding an image without generating blur with the elapse of time in the case of long-time preservation under a high temperature and high humidity condition after printing, reduced in curling and excellent in printer feed properties. <P>SOLUTION: In the ink jet recording sheet constituted by providing a colorant receiving layer having a three-dimensional reticulated structure, which contains fine particles of an inorganic pigment, a water soluble resin, a crosslinking agent capable of crosslinking the water soluble resin and a basic organic cation mordant dye, on a support, the crosslinking agent comprises a compound of a Group IV element. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material suitable for ink jet recording using a liquid ink such as an aqueous ink or an oil ink, or a solid ink which is solid at room temperature and is melted and liquefied to be used for printing. More specifically, the present invention relates to a recording sheet having excellent ink receiving performance.

[0002]

2. Description of the Related Art In recent years, along with the rapid development of the information industry, various information processing systems have been developed, and recording methods and devices suitable for the information systems have been developed and put into practical use. Among the above recording methods, the inkjet recording method is capable of recording on various recording materials, hardware (device)
Has been widely used not only in offices but also in so-called home use because it is relatively inexpensive, compact, and excellent in quietness.

With the recent increase in the resolution of ink jet printers, it has become possible to obtain so-called photograph-like high-quality recorded matter. On the other hand, with the development of hardware (device), various recording sheets for inkjet recording have been developed. The properties required of the recording sheet for inkjet recording are generally:
(1) quick-drying property (high ink absorption speed), (2) proper and uniform ink dot diameter (no bleeding), (3) good graininess,
(4) High circularity of dots, (5) High color density, (6) High saturation (no dullness),
(7) Light resistance and water resistance of the printed area are good, (8) Whiteness of the recording sheet is high, (9) Storage stability of the recording sheet is good (yellowing coloring and images during long-term storage) (No bleeding), (10) difficult deformation, good dimensional stability (curl is sufficiently small), (11) good hard running property, and the like. In addition to the above characteristics, the photo glossy paper used for the purpose of obtaining a so-called photographic-like high-quality recorded material has glossiness, surface smoothness, and a photographic paper-like texture similar to silver halide photographs. Required.

Recording sheets used for ink jet recording include, for example, JP-A-55-51583, JP-A-55-144172, JP-A-55-150395 and JP-A-55-150395.
6-148582, 56-148583, 56
-148584, 56-148585, 57-
14091, 57-385, 57-129.
No. 778, No. 57-129979, No. 60-2190.
No. 84, No. 60-245588, etc.
It is known that a pigment such as silica and a water-soluble binder are coated on a support such as paper or plastic film. However, all of these proposed recording sheets have very low glossiness, which is insufficient for use as a photo glossy paper.

Japanese Unexamined Patent Publication (Kokai) No. 12-212135 describes an ink jet recording sheet containing a vapor phase silica and a cationic polymer having a constitutional unit of a polydiallylamine derivative, which also has an image printing density. , Low sharpness and gloss. Furthermore, JP-A-12-
No. 211241 discloses a pH containing silica prepared by vapor phase method.
A coating liquid for inkjet recording using an aqueous dispersion of 1.0 to 4.5 is described, but this also shows the print density of an image,
The sharpness and glossiness are low, and furthermore, the surface of the recording sheet is cracked.

[0006] There is also proposed a method in which after vapor phase method silica is dispersed with a cationic polymer, a coating solution containing PVA and a curing agent for PVA is applied and dried at a low temperature.
The coating solution easily aggregates, and the sharpness and glossiness of the image are still insufficient. Further, the recording sheet may curl under low humidity, which may result in poor running on the printer.

On the other hand, JP-A-6-032046 proposes an ink jet recording sheet (aqueous ink jet recording paper) containing amorphous fine powder silica, polyvinyl alcohol containing a silanol group, and a zirconium compound as main components. Has been done. These recording sheets satisfy some required characteristics in terms of ink absorption speed, image resolution, and speeding up of printing, but they are inferior in terms of gloss and are not sufficient for use as photoglossy paper. It was

JP-A-10-309862 discloses a coloring material receiving layer containing a hydrophilic polymer having a hydroxyl group, a polyvalent carboxylic acid and, if necessary, a compound of Group 4 element of the periodic table on a support. Inkjet recording sheet (water-based inkjet recording paper) on which (ink absorbing layer) is formed
Is proposed. These recording sheets satisfy some required characteristics in terms of water resistance,
The ink absorption rate was insufficient and bleeding occurred over time.

Further, in JP-A-11-078220, a color material receiving layer (ink receiving layer) in which polyvinylpyrrolidone, a cationic substance and a zirconium compound are added to polyvinyl alcohol having a low saponification degree on a support is disclosed. ) Has been proposed, an inkjet recording sheet (recording body) has been proposed. These recording sheets satisfy some required characteristics in terms of image resolution and water resistance, but the ink absorption rate was insufficient and bleeding occurred over time.

As described above, the color material receiving layer is strong without cracks and the like, while having good ink absorbability, excellent bleeding with time, and the formed image has high light fastness. The present situation is that an ink jet recording sheet has not yet been provided while ensuring such ink receiving performance and having less incurl that causes poor running properties during printing.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the various problems in the prior art and achieve the following objects. That is, the present invention has a high glossiness on the recording surface, is excellent in ink absorption, can obtain a high-resolution and high-density image, and can be stored for a long time in a high temperature and high humidity environment after printing. An object of the present invention is to provide an inkjet recording sheet that can stably hold an image without causing bleeding, has less curl, and is excellent in printer transportability.

[0012]

Means for Solving the Problems As a result of intensive investigations by the present inventors regarding a colorant receiving layer, inorganic fine particles such as silica particles of vapor phase method, a water-soluble resin such as polyvinyl alcohol, and a crosslinking agent were used. The inventors have found that the above problems can be solved by forming a coloring material receiving layer containing a compound of the periodic table group 4 element such as a zirconium compound and a basic organic cation mordant, and completed the present invention. That is, the present invention is

<1> Inorganic pigment fine particles are provided on a support,
An ink jet recording sheet comprising a water-soluble resin, a cross-linking agent capable of cross-linking the water-soluble resin, and a colorant-receiving layer having a three-dimensional network structure containing a basic organic cation mordant, The inkjet recording sheet is characterized in that the cross-linking agent is a group 4 element compound of the periodic table.

<2> The ink jet recording sheet according to <1>, wherein the water-soluble resin is polyvinyl alcohol and the crosslinking agent is a zirconium compound.

<3> The ink jet recording sheet according to <1> or <2>, wherein the inorganic pigment fine particles are gas phase method silica fine particles having a specific surface area of 200 m ² / g or more as measured by the BET method. Is.

<4> The basic organic cation mordant is polyallylamine, <1> to
The inkjet recording sheet according to any one of <3>.

<5> The inkjet recording sheet according to any one of <1> to <4>, wherein the crosslinking agent further contains a boron compound.

<6> The color material receiving layer is provided on a thermoplastic resin layer, <1> to <5.
> The ink jet recording sheet according to any one of <1>.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The ink jet recording sheet of the present invention has a three-dimensional network structure on a support, and fine inorganic pigment particles, a water-soluble resin, and a crosslinking agent capable of crosslinking the water-soluble resin. And a basic organic cation mordant are provided, and the cross-linking agent is a compound of Group 4 element of the periodic table. Less than,
The color material receiving layer in the present invention will be described.

<Coloring Material Receiving Layer> The coloring material receiving layer in the present invention has a three-dimensional network structure, and is a periodical agent as a cross-linking agent capable of crosslinking the inorganic pigment fine particles, the water-soluble resin and the water-soluble resin. It contains at least a Group 4 element compound and a basic organic cation mordant, and may further contain other components such as a light resistance improver, if necessary.

(Inorganic pigment fine particles) Examples of the inorganic pigment 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, boehmite, pseudo-boehmite and the like can be mentioned. Of these, silica fine particles are preferable.

Further, the silica fine particles in the present invention are B
More preferred are gas phase method silica fine particles having a specific surface area of 200 m ² / g or more by the ET method (hereinafter sometimes simply referred to as “high specific surface area gas phase method silica fine particles”). BET
The law means "Technical data No. 10 of Nippon Aerosil Co., Ltd."
The method for measuring the average primary particle size is described in paragraphs 2 and 2 above. The silica fine particles in the present invention preferably have a specific surface area of 200 m ² / g or more calculated using the BET method, more preferably 220 m ² / g or more, and further preferably 300 m ² / g or more.

The silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to the production method. In the above-mentioned wet method, a method in which activated silica is generated by acid decomposition of a silicate, polymerized appropriately, 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),
The mainstream method is to obtain anhydrous silica by a method of heating and vaporizing silica sand and coke by an arc in an electric furnace, and oxidizing this with air (arc method). It means anhydrous silica fine particles obtained by the phase method.

The vapor-phase method silica fine particles have different properties from the hydrous silica, such as the density of silanol groups on the surface and the presence or absence of pores, and show different properties, but form a three-dimensional structure having a high porosity. Suitable for 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 fine particles, since the density of silanol groups on the surface of the fine particles is as few as 2-3 / nm ² , it becomes a sparse soft coagulation (flocculate), resulting in a structure having a high porosity. Presumed.

Since the high specific surface area vapor-phase method silica fine particles have a particularly large specific surface area, they have high ink absorption and retention efficiency, and also have a low refractive index. It is characterized in that it is possible to impart transparency to the material receiving layer and obtain high color density and good color development. 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 high specific surface area vapor phase method silica fine particles is preferably 30 nm or less, and 20 nm or less.
The following is more preferable, and 10 nm or less is particularly preferable,
Most preferred is 3 to 10 nm. The vapor-phase method silica fine particles are likely to adhere to each other due to hydrogen bonds due to silanol groups, so that a structure having a large porosity can be formed when the average primary particle diameter is 30 nm or less, and the ink absorption characteristics are effective. Can be improved.

The present invention also includes fine particles of hydrous silica, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, boehmite, pseudoboehmite, etc. It is also preferable to use the other inorganic pigment fine particles in combination with the high specific surface area vapor-phase method silica fine particles. When the other inorganic pigment fine particles and the vapor phase silica fine particles are used in combination, in all the inorganic pigment fine particles,
The content of the vapor-phase method silica fine particles is preferably 90% by mass or more, and more preferably 95% by mass or more.

(Water-Soluble Resin) The water-soluble resin in the present invention is, for example, a resin having a hydroxyl group as a hydrophilic structural unit, such as polyvinyl alcohol (PV
A), cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, cellulose resin [methyl cellulose (MC), ethyl cellulose (E
C), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), etc.], chitins, chitosans, starches; polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PE) which are resins having an ether bond.
G), polyvinyl ether (PVE); polyacrylamide (PA which is a resin having an amide group or an amide bond)
AM), polyvinylpyrrolidone (PVP) and the like. Further, polyacrylic acid salts, maleic acid resins, alginates and gelatins having a carboxyl group as a dissociative group can be mentioned. As the water-soluble resin in the present invention, PVA is preferable, and among them, the saponification degree is 70-
99% PVA is more preferable, and PVA having a saponification degree of 88 to 99% is most preferable.

Further, the PVA has a hydroxyl group in its structural unit. When silica fine particles are used as the inorganic pigment fine particles, the hydroxyl groups and silanol groups on the surface of the silica fine particles form a hydrogen bond to form silica fine particles. It facilitates the formation of a three-dimensional network structure having secondary particles as chain units. It is considered that the formation of the three-dimensional network structure makes it possible to form a coloring material receiving layer having a porous structure with a high porosity. In the ink jet recording, the porous color material receiving layer thus obtained can rapidly absorb the ink due to the capillary phenomenon and form dots having good roundness without ink bleeding.

The content of the water-soluble resin is preferably 9 to 40% by mass, more preferably 12 to 33% by mass, based on the total mass of the solid content of the colorant receiving layer. The content is
When it is less than 9% by mass, the film strength is lowered and cracks are likely to occur during drying, and when it exceeds 40% by mass, the voids are easily clogged by the resin, resulting in a decrease in the void ratio and the ink. Absorption may be reduced.

The content ratio of the inorganic pigment fine particles (preferably high specific surface area vapor-phase method silica fine particles; i) and the water-soluble resin (p) [PB ratio (i: p), 1 part by weight of water-soluble resin The mass of pigment fine particles] also has a great influence on the film structure of the colorant receiving layer. That is, as the PB ratio increases, the porosity, pore volume, and surface area (per unit mass) increase. Specifically, the PB ratio (i: p) is 1.
5: 1 to 10: 1 is preferred. If the PB ratio exceeds 10: 1, that is, if the PB ratio becomes too large, the film strength may decrease and cracks may easily occur during drying, and the ratio is less than 1.5: 1, that is, the PB ratio is too small. As a result, the voids are more likely to be blocked by the resin, and as a result, the void ratio may decrease and the ink absorbency may decrease.

When passing through the transport system of an ink jet printer, stress may be applied to the recording sheet.
It is necessary for the colorant receiving layer to 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. In this case, the PB ratio is preferably 5: 1 or less, and is preferably 2: 1 or more from the viewpoint of ensuring high-speed ink absorbency in an inkjet printer.

For example, the PB ratio of the fumed silica fine particles having an average primary particle diameter of 20 nm or less and the water-soluble resin is 2: 1 to.
When a coating solution completely dispersed in an aqueous solution at a ratio of 5: 1 was coated on a support and the coating layer was dried, a three-dimensional network structure having secondary particles of silica fine particles as chain units was formed, and the average fine It is possible to easily form a translucent porous film having a pore diameter of 30 nm or less, a porosity of 50% or more, a pore specific volume of 0.5 ml / g or more, and a specific surface area of 100 m ² / g or more.

The inorganic pigment fine particles and the water-soluble resin may each be a single material or a mixed system of a plurality of materials.

(Crosslinking Agent) In the coloring material receiving layer of the ink jet recording sheet of the present invention, a coating layer containing a water-soluble resin contains a crosslinking agent, and the crosslinking agent cures the water-soluble resin by a crosslinking reaction. It is a layer. The cross-linking agent contains at least inorganic pigment fine particles and a water-soluble resin, and forms a coating material for the colorant-receiving layer having a porous structure (hereinafter, may be simply referred to as "coating fluid for colorant-receiving layer"). In addition, it is also possible to add it to a solution containing a basic organic cationic mordant described below (hereinafter, may be simply referred to as “cationic mordant”) and add it. When the crosslinking agent is added using a solution containing a cationic mordant containing the above-mentioned crosslinking agent (hereinafter, may be simply referred to as a “crosslinking agent mordant mixed solution”), the coating liquid for the colorant-receptive layer is It is preferably performed at the same time as the coating, or before the coating layer formed by coating the coating liquid for the color material receiving layer exhibits a decreasing rate of drying. By this operation, it is possible to effectively prevent the occurrence of cracks that occur during the drying of the coating layer. That is, the cross-linking agent mordant mixed solution permeates into the coating layer at the same time as the coating liquid for the color material receiving layer is coated, or before the coating layer starts to exhibit the rate of decrease in drying rate, resulting in water solubility in the coating layer. By rapidly reacting with the resin and gelling (curing) the water-soluble resin, the film strength of the coating layer is immediately and significantly improved.

In the present invention, the cross-linking agent is a compound of Group 4 element of the periodic table. Examples of the Group 4 element of the periodic table include titanium, zirconium, hafnium and the like, and among these, zirconium is preferable. The group 4 element compound of the periodic table is water-soluble which can be completely dissolved in water or dispersed in a colloidal form. Water-soluble compounds of the Group 4 element compounds of the periodic table include oxides (including complex oxides and oxyacid salts), halides, organic acid salts, inorganic acid salts, complexes and the like. The valence of an element of Group 4 of the periodic table such as zirconium is not particularly limited, but is usually divalent, trivalent, particularly tetravalent. These compounds can be used alone or in combination of two or more kinds.

As the oxide, for example, ZrO₂,
ZrO₂・ XH₂O, ZrO₃・ XH₂O, zirconic acid and
And corresponding titanium oxides (TiO₂, Titanic acid
Etc.), hafnium oxide, etc.
Examples of the oxyacid salt include M₂ZrO₃, M_FourZrO
_Four(M is an alkali metal, etc.), and
Examples include complex oxides of tan and hafnium and oxyacid salts.
It Examples of the halide include ZrCl₂,
ZrBr₂, ZrI₂, ZrCl₃, ZrBr₃, Zr
I₃, ZrCl_Four, ZrBr_Four, ZrI_Four, Halogenated zirconium
Conyl (ZrOCl₂, Zr ₂O₃Cl₂Etc.), and this
Corresponding to titanium halides (TiCl₃, Ti
Cl_Four, TiOCl₂Etc.) and hafnium halides, etc.
Can be illustrated.

Examples of the organic acid salt include zirconium acetate, zirconium propionate, zirconyl acetic acid, zirconium oxalate, zirconium tartrate, zirconium benzoate, and corresponding organic acid salts of titanium and hafnium. As the inorganic acid salt, for example, zirconium nitrate, zirconyl nitric acid, zirconium sulfate, zirconyl sulfate, zirconium phosphate,
Examples thereof include zirconyl phosphoric acid, and corresponding inorganic acid salts of titanium (titanium sulfate, titanium oxysulfate, etc.) and hafnium inorganic acid salts.

Examples of the complex include a ligand (OH, an alkoxy group, an acyl group, an alkoxycarbonyl group, an organic acid,
Acetylacetonato, halogen atom, CO, CN, H ₂
O (aco), phosphorus compounds such as triphenylphosphine,
Various complexes including nitrogen-containing compounds, etc., for example, oxalate complexes and the like. As the complex, for example,
Zirconium acetylacetonato complex (Zr (acac) ₄
Etc.), zirconyl acetylacetonato complex (ZrO (ac
ac) ₂ etc.), titanium acetylacetonato complex (Ti (aca
c) ₄ etc.), titanyl acetylacetonato complex (TiO 2
(Acac) ₂ etc.) and the like.

The cross-linking agent in the present invention has been
Used in the colorant receiving layer in addition to the compounds of Group 4 element of the periodic table
Suitable known cross-linking agent in relation to the water-soluble resin
You may select and use together. Known cross-linking agents that can be used in combination
As a cross-linking reaction is rapid, a boron compound
Are preferred, for example, borax, boric acid, borate (eg
For example, orthoborate, InBO₃, ScBO₃, YB
O₃, LaBO₃, Mg₃(BO ₃)₂, Co₃(BO₃)₂, Niho
Oxalate (eg Mg₂B₂O_Five, Co₂B₂O_Five), Metaho
Oxalates (eg LiBO₂, Ca (BO₂)₂, NaB
O₂, KBO₂), Tetraborate (eg Na₂B_FourO₇・
10H₂O), pentaborate (eg KB_FiveO₈・ 4H
₂O, Ca₂B₆O₁₁・ 7H₂O, CsB_FiveO_Five) Etc.
In addition, glyoxal and melamine formual
Dehydrates (eg, methylol melamine, alkylated methyl
Roll melamine), methylol urea, resole resin,
Examples include lisocyanate and epoxy resin
It Among them, borax and ho
Uric acid and borate are more preferable, and boric acid is most preferable.
Yes.

When gelatin is used as the water-soluble resin, the following compounds known as hardeners for gelatin can be used in combination with the above-mentioned Group 4 element compounds of the periodic table. 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,
Active halogen compounds such as 4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N'-ethylenebis (vinylsulfonylacetamide), 1, 3,5-
Active vinyl compounds such as triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin;

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 mucophenoxycyclo acid; dioxane compounds such as 2,3-dihydroxydioxane; chromium alum, potassium alum, zirconium sulfate, Chromium acetate and the like.

As the combination of the water-soluble resin and the cross-linking agent in the present invention, a combination of PVA (water-soluble resin) and a zirconium compound (cross-linking agent) is preferable. A combination of PVA (water-soluble resin) and a mixture (crosslinking agent) of a zirconium compound and a boron compound is also preferable. When the coating liquid for the color material receiving layer contains a cross-linking agent together with the inorganic pigment fine particles and the water-soluble resin, the content of the cross-linking agent in the coating liquid for the color material receiving layer is 1 to the water-soluble resin 1 by mass ratio. , Preferably 0.1 to 5.0, and 0.2 to
3.0 is more preferable.

On the other hand, when the cross-linking agent is applied as a cross-linking agent mordant mixed solution, the cross-linking agent is used by dissolving it in water and / or an organic solvent. In this case, the concentration of the cross-linking agent in the cross-linking agent mordant mixed solution is preferably 0.05 to 10% by mass, and particularly preferably 0.1 to 7% by mass. When a known cross-linking agent such as a boron compound is used together with a compound of the periodic table group 4 element as a cross-linking agent, the ratio of the known cross-linking agent to the compound of the periodic table group 4 element is a mass ratio of the periodic table 4
0.1 to 5.0 is preferable with respect to the group 1 element compound,
0.5 to 3.0 is more preferable.

As the solvent in the cross-linking agent mordant mixed solution, water is generally used, and an aqueous mixed solvent containing an organic solvent miscible with the water may be used. As the organic solvent, any solvent can be used as long as the crosslinking agent can be dissolved therein. Examples thereof include alcohols such as methanol, ethanol, isopropyl alcohol and glycerin; ketones such as acetone and methyl ethyl ketone; methyl acetate, ethyl acetate and the like. Ester; an aromatic solvent such as toluene; an ether such as tetrahydrofuran; and a halogenated carbon solvent such as dichloromethane.

(Basic organic cation mordant) In the present invention, a basic organic cation mordant is contained in the colorant-receiving layer in order to further improve the water resistance and bleeding resistance of the formed image. By allowing the cationic mordant to be present in the colorant-receiving layer, the colorant can be interacted with the liquid ink having the anionic dye as the colorant to stabilize the colorant, thereby improving water resistance and blurring over time. .

However, when the cationic mordant is added directly to the coating solution for forming the colorant-receiving layer, silica, etc.
There is a possibility that aggregation may occur with the inorganic pigment fine particles having an anion charge, but if a method of preparing and coating each as an independent solution is used, there is no need to worry about aggregation of the inorganic pigment fine particles. Therefore, in the present invention, it is preferable to prepare and use a solution containing a mordant separately from the solution containing the inorganic pigment fine particles (coating solution for the colorant receiving layer), and further add a crosslinking agent as described above. It is also possible to prepare and use a cross-linking agent mordant mixed solution.

As the cationic mordant, a polymer mordant having a primary to tertiary amino group and its salt or a quaternary ammonium salt group is preferably used, but a cationic non-polymer mordant can also be used. . As the polymer mordant, those obtained as a homopolymer of a monomer having the following base, or a copolymer or a condensation polymer of the monomer with another monomer are preferable. As the cationic mordant in the present invention, polyvinylamine,
Polyallylamine is preferred, and polyallylamine is more preferred.

Examples of the monomer include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride,
Triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N, N-dimethyl-N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-N-p -Vinylbenzylammonium chloride, N, N-dimethyl-N-n-propyl-N-
p-vinylbenzyl ammonium chloride, N, N-
Dimethyl-N-n-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-benzyl-Np- Vinylbenzyl ammonium chloride, N, N-dimethyl-
N- (4-methyl) benzyl-N-p-vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-N-p-vinylbenzylammonium chloride,

Trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl- m
-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.

Among them, trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, triethyl-2- (acryloyloxy) ethyl Ammonium chloride, trimethyl-3- (methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl-2- (methacryloylamino)
Ethyl ammonium chloride, trimethyl-2- (acryloylamino) ethyl ammonium chloride, triethyl-2- (acryloylamino) ethyl ammonium chloride, trimethyl-3- (methacryloylamino) propyl ammonium chloride, triethyl-
3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride, triethyl-3- (acryloylamino) propylammonium chloride,

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride,
N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl-3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium Bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-
3- (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.

The polymer mordant is a water-soluble polymer,
Water-dispersible latex particles can be used in any form.

Further, as a polymer mordant, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethylenimine, polyallylamine, polyallylamine hydrochloride, polyamide-polyamine resin, cationized starch, dicyandiamide. Formalin condensate, dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine and the like can also be mentioned as preferable ones.

The molecular weight of the polymer mordant is 1
000-200000 is preferable. The molecular weight is 10
When it is less than 00, the water resistance of the formed color material-receiving layer may be insufficient, and when it exceeds 200,000, the viscosity may be high and the handling aptitude may be deteriorated.

On the other hand, as the non-polymeric mordant, a compound having a quaternary ammonium salt group having a total number of carbon atoms of 12 or more, preferably 18 or more is suitably used.

The content of the cationic mordant is as follows.
0.5 to 25.0 based on the total solid content of the colorant receiving layer
Mass% is preferable, and 1.0-15.0 mass% is more preferable. If the content is less than 0.5% by mass, sufficient water resistance may not be obtained, and if it exceeds 25.0% by mass, the ink absorption may deteriorate.

(Other Components) The colorant receiving layer in the present invention is mainly composed of the above-mentioned inorganic pigment fine particles, a water-soluble resin, a cross-linking agent and a cationic mordant, but optionally contains the following components. You may stay. For the purpose of suppressing the deterioration of the coloring material, various ultraviolet absorbers, antioxidants, singlet oxygen quenchers and the like may be contained. Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, and benzotriazolylphenol derivatives. For example, α-cyano-phenyl butyl cinnamate, o-benzotriazole phenol, o-benzotriazole-p
-Chlorophenol, o-benzotriazole-2,4
-Di-t-butylphenol, o-benzotriazole-2,4-di-t-octylphenol and the like can be mentioned. A hindered phenol compound can also be used as an ultraviolet absorber, and specifically, at least one of 2-position and 6-position.
Phenol derivatives in which one or more positions are substituted with branched alkyl groups are preferred.

Further, a benzotriazole type ultraviolet absorber, a salicylic acid type ultraviolet absorber, a cyanoacrylate type ultraviolet absorber, an oxalic acid anilide type ultraviolet absorber and the like can also be used. For example, JP-A-47-1053
No. 7, 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 and the like.

A fluorescent whitening agent can also be used as an ultraviolet absorber, and examples thereof include a coumarin-based fluorescent whitening agent. Specifically, Japanese Examined Patent Publication Nos. 45-4699 and 54-5324.
No. etc.

Examples of the antioxidant include European Patent Nos. 223739, 309401, 309402, 310551, and 31.
No. 0552, No. 459416, German Published Patent No. 3435443, and Japanese Patent Laid-Open No. 54-48535.
No. 60-107384 and No. 60-107.
No. 383, No. 60-125470, No. 60-
No. 125471, No. 60-125472, No. 60-287485, No. 60-287486, No. 60-287487, and No. 60-28748.
8 gazette, the same 61-160287 gazette, the same 61-18.
5483, 61-211079 and 62.
No. 146678, No. 62-146680,
62-146679, 62-282885, 62-262047, 63-0511.
74, 63-89877, 63-88.
No. 380, No. 66-88381, No. 63-1.
No. 13536,

63-163351 and 63-2.
No. 03372, No. 63-224989, No. 6
No. 3-251282, No. 63-267594, No. 63-182484, Japanese Patent Laid-Open No. 1-2392.
82, JP-A-2-262654, and 2-7.
No. 1262, No. 3-121449, and No. 4-2.
No. 91685, No. 4-291684, No. 5-
No. 61166, No. 5-119449, No. 5-
No. 188687, No. 5-188686, No. 5
-110490 gazette, the same 5-1108437 gazette,
No. 5-170361, Japanese Patent Publication No. 48-43295, No. 48-33212, and U.S. Pat. No. 4,814.
No. 262, No. 4980275, etc. are mentioned.

Specifically, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2 -Dihydroquinoline, 6-ethoxy-1-
Phenyl-2,2,4-trimethyl-1,2,3,4-
Tetrahydroquinoline, 6-ethoxy-1-octyl-
2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, nickel cyclohexanoate, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2 -Ethylhexane, 2
-Methyl-4-methoxy-diphenylamine, 1-methyl-2-phenylindole and the like can be mentioned.

The light resistance improvers may be used alone or in combination of two or more kinds. The light resistance improver may be made water-soluble, dispersed, emulsified, or contained in microcapsules. The amount of the light resistance improver added is preferably 0.01 to 10% by mass of the coating liquid for the colorant receiving layer.

Further, for the purpose of enhancing the dispersibility of the fine particles of the inorganic pigment, various inorganic salts may be contained, and an acid, an alkali or the like may be contained as a pH adjusting agent. Further, various surfactants are used for the purpose of improving coating suitability and surface quality, and surfactants having ionic conductivity and metal oxide fine particles having electronic conductivity are used for the purpose of suppressing frictional electrification and peeling electrification on the surface. In addition, various matting agents may be included for the purpose of reducing the frictional properties of the surface.

<Support> As the support, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used. In order to make the most of the transparency of the colorant receiving layer, it is preferable to use a transparent support or a highly glossy opaque support. In the present invention, it is particularly preferable to use a paper support made of a raw paper coated with a thermoplastic resin such as polyethylene or a transparent film such as a PET film.

As a material usable for the transparent support, a material which is transparent and has a property of withstanding radiant heat when used in an OHP or a 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 in terms of handleability.

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 determined according to the method described in 2 (75 degree specular gloss test method for paper and board). Specific examples include the following supports.

For example, art paper, coated paper, cast coated paper, high gloss paper support such as RC paper and baryta paper used for silver salt photographic support; polyesters such as polyethylene terephthalate (PET) Cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide were made opaque by containing white pigments and the like (surface calendered. High gloss film; or a coating layer of polyolefin containing or not containing a white pigment on the surface of the high gloss film containing the various paper supports, the transparent support or the white pigment. A support provided with Further, 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.

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

Further, the support is subjected to corona discharge treatment,
Those subjected to glow discharge treatment, flame treatment, ultraviolet irradiation treatment and the like may be used.

Next, the base paper used for the paper support 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, NBSP, LD
Any of P, NDP, LUKP and NUKP can be used, but LBKP, NBSP, LB with a large amount of short fibers
It is preferable to use more SP, NDP, and LDP. However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

The pulp is preferably a chemical pulp containing few impurities (sulfate pulp or sulfite pulp),
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, starch, polyacrylamide,
A paper strength enhancer such as polyvinyl alcohol, a fluorescent brightening agent, a water retention agent such as polyethylene glycols, 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 calculated mass% defined in 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 size 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 base paper in the present invention preferably has the front and back surfaces coated with a thermoplastic resin, and polyethylene is preferable among the thermoplastic resins. The polyethylene is mainly low-density polyethylene (LDPE)
And / or high density polyethylene (HDPE), but some other LLDPE, polypropylene, etc. can also be used.

In particular, the polyethylene layer on the side of forming the colorant receiving layer is formed by adding rutile or anatase type titanium oxide to polyethylene, as is commonly used in photographic printing paper, to obtain opacity and whiteness. Those improved are preferable. Here, the content of titanium oxide is preferably about 3 to 20 mass% with respect to polyethylene, and 4
-13 mass% is more preferable.

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

As described above, according to the present invention, it is possible to improve the print density, sharpness and gloss of an image and suppress the occurrence of curl without deteriorating the performance of other inks. Moreover, since the colorant receiving layer in the present invention contains the inorganic pigment fine particles and has a three-dimensional network structure (preferably having a porosity of 50 to 80%), it exhibits good ink absorption and forms a high resolution image. At the same time, bleeding over time in a high temperature and high humidity environment is suppressed, and excellent ink receiving performance can be secured at the same time.

(Preparation of Inkjet Recording Sheet) The coloring material receiving layer of the inkjet recording sheet of the present invention comprises a support containing a solution containing a crosslinking agent together with inorganic pigment fine particles and a water-soluble resin as a coating material for the coloring material receiving layer. Or a method of applying a solution containing at least a mordant and not containing a crosslinking agent (hereinafter sometimes simply referred to as "mordant solution") onto the coating material for the colorant-receptive layer, or a colorant-receptive layer. It is preferable that a solution containing inorganic pigment fine particles and a water-soluble resin is applied as a coating solution for a coating solution on a support, and a cross-linking agent mordant mixed solution is applied onto the coating solution for a color material receiving layer. Further, the coloring material receiving layer of the inkjet recording sheet of the present invention comprises a coating liquid for the coloring material receiving layer, a mordant solution or a cross-linking agent and a mordant mixed solution, and a barrier liquid (provided that the cross-linking agent does not react with the cross-linking agent. It can also be obtained by simultaneously applying and curing a support containing a mordant in at least one of a solution containing an agent and a barrier liquid.

As described above, in the present invention, the mordant solution or the cross-linking agent mordant mixed solution and the colorant-receptive-layer coating liquid containing the inorganic pigment fine particles are separately prepared. That is, when the mordant solution is added to the coating material for the colorant-receiving layer, the mordant is cationic, so that coagulation may occur in the presence of inorganic pigment fine particles having an anionic charge on the surface, such as silica. However, a mordant solution or a cross-linking agent mordant mixed solution, and a coating material for the colorant-receptive layer are prepared independently, and if a method of individually coating is adopted, it is not necessary to consider aggregation of the inorganic pigment fine particles, The selection range of mordants is expanded.

In the present invention, the coating liquid for the color material receiving layer is
For example, it can be prepared as follows. That is, silica fine particles having an average primary particle diameter of 20 nm or less are added to water (for example, 10 to 20% by mass), and a high-speed rotating wet colloid mill (for example, CLEARMIX (M Technique Co., Ltd.) is used.
20) under the conditions of high-speed rotation of 10000 rpm (preferably 5000 to 20000 rpm).
After dispersing for 10 minutes (preferably 10 to 30 minutes), PV
It can be prepared by adding an aqueous solution of a water-soluble resin such as A (for example, so that the water-soluble resin has a mass of about 1/3 of silica) and further performing dispersion under the same rotation conditions as described above. The obtained coating liquid is a uniform sol, and a porous coloring material-receiving layer having a three-dimensional network structure can be formed by coating and forming this on a support by the coating method described below. In the coating liquid for the color material receiving layer, if necessary,
Further, a surfactant, a pH adjusting agent, an antistatic agent, etc. can be added.

The coating of the coating material for the color material receiving layer is carried out, for example, by an extrusion die coater, an air doctor coater,
It can be performed by a known coating method such as a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, or a bar coater.

In the present invention, the colorant-receiving layer cured by the crosslinking reaction can be obtained by allowing the water-soluble resin and the crosslinking agent to coexist by the method described above. The mordant solution or the cross-linking agent mordant mixed solution may be applied after the coating liquid for the colorant-receptive layer is applied to form the coating layer and before the coating layer exhibits the rate of decreasing rate of drying. That is,
It is preferably manufactured by applying the mordant solution or the cross-linking agent mordant mixed solution after coating the coating liquid for the colorant receiving layer while the coating layer shows a constant rate of drying.

The term "before the coating layer shows the rate of decrease in drying rate" usually means a few minutes immediately after the coating of the coating material for the colorant receiving layer, and during this period, the coating layer The constant drying rate, which is a phenomenon in which the content of the solvent decreases in proportion to time, is shown. For the time showing the constant rate of drying, see Chemical Engineering Handbook (p.707-712, Maruzen Co., Ltd.).
Published, October 25, 1980).

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

As a method of applying the above-mentioned coating layer before the rate of drying rate is decreased, a method of further coating a mordant solution or a cross-linking agent mordant mixed solution on the coating layer,
Examples thereof include a method of spraying by a method such as spraying, a method of immersing the support on which the coating layer is formed in a mordant solution or a cross-linking agent mordant mixed solution, and the like.

In the above-mentioned method, as a coating method for coating the mordant solution or the cross-linking agent mordant mixed solution, for example, a curtain flow coater, an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll is used. A known coating method such as a coater or a bar coater can be used. However, like the extrusion die coater, curtain flow coater, bar coater, etc.
It is preferable to use a method in which the coater does not come into direct contact with the already formed coating layer.

The coating amount of the mordant solution or the cross-linking agent mordant mixed solution applied on the colorant receiving layer is generally 0.05 to 5.0 g / m ^{2 in} terms of mordant,
˜2.0 g / m ² is preferred.

After applying the mordant solution or the cross-linking agent mordant mixed solution, it is generally 0.5 to 30 at 40 to 180 ° C.
It is heated for a minute, and dried and cured. Among them, 40
It is preferable to heat at ~ 150 ° C for 1 to 20 minutes. In the present invention, heating at 40 to 80 ° C is preferably performed for 2 to 10 minutes.

The mordant solution or the cross-linking agent mordant mixed solution may be applied at the same time as the coating liquid for the colorant receiving layer is applied. In this case, the coating material for the colorant receiving layer and the mordant solution or the mixed solution of the crosslinking agent and the mordant are simultaneously coated on the support so that the coating solution for the colorant receiving layer contacts the support (multilayer coating), After that, the colorant receiving layer can be formed by drying and curing.

The simultaneous coating (multi-layer coating) can be carried out by a coating method using, for example, an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried, and the drying in this case is generally performed by heating the coating layer at 40 to 150 ° C. for 0.5 to 30 minutes, preferably 40 to 100.
It is carried out by heating at 0 ° C for 0.5 to 20 minutes. In the present invention, heating at 40 to 80 ° C is preferably performed for 3 to 15 minutes.

When the simultaneous coating (multi-layer coating) is carried out by, for example, an extrusion die coater, the two kinds of coating liquids discharged at the same time are in the vicinity of the discharge port of the extrusion die coater, that is, before being transferred onto the support. Is formed in multiple layers, and in that state, multiple layers are applied on the support. Since the two-layer coating solution that has been overlaid before coating tends to cause a cross-linking reaction at the interface between the two solutions when it is transferred to the support, the two solutions to be discharged are mixed near the discharge port of the extrusion die coater. May increase the viscosity, which may hinder the coating operation. Therefore, in the case of simultaneous coating as described above, the coating liquid for the colorant receiving layer and the barrier layer liquid (intermediate layer liquid) made of a material which does not react with the crosslinking agent together with the mordant solution or the cross-linking agent mordant mixed solution It is preferable to intervene between the two liquids and apply simultaneously in three layers.

The barrier layer liquid can be selected without particular limitation as long as it can form a liquid film without reacting with the crosslinking agent. For example, an aqueous solution containing a trace amount of a water-soluble resin that does not react with the crosslinking agent, water, and the like can be given. The water-soluble resin is used in consideration of coatability for the purpose of a thickener or the like, for example, hydroxypropylmethyl cellulose,
Methyl cellulose, hydroxyethyl methyl cellulose
And polymers such as polyvinylpyrrolidone and gelatin.

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 the properties, glossiness, transparency and coating film strength. However, since the calendering process may cause a decrease in the porosity (that is, ink absorption may decrease), 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, more preferably 40 to 100 ° C. Further, the linear pressure between the rolls at the time of calendar treatment is preferably 50 to 400 kg / cm, and 10
0 to 200 kg / cm is more preferable.

In the case of ink jet recording, the layer thickness of the coloring material receiving layer needs to be determined in relation to the porosity in the layer, since 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 color material receiving layer is preferably 0.005 to 0.030 μm in terms of median diameter, and 0.01 to
0.025 μm is more preferable. The porosity and the median pore diameter can be measured using a mercury porosimeter (trade name: Boasizer 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.

On the support, for the purpose of improving the adhesiveness between the color material receiving layer and the support, adjusting the electric resistance, and the like,
An undercoat layer may be provided. The colorant receiving layer may be provided on only one side of the support, or may be provided on both sides of the support for the purpose of suppressing deformation such as curling. In the case of using for OHP or the like, and when the color material receiving layer is provided only on one side of the support, the surface on the opposite side or both sides thereof,
An antireflection film may be provided for the purpose of enhancing light transmittance.

[0104]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. still,
All “parts” and “%” in the examples represent “parts by mass” and “mass%”.

Example 1-Preparation of Support-Wood pulp consisting of 100 parts of LBKP was processed with a double disc refiner to obtain Canadian freeness of 300 ml.
Beaten to 0.5 parts of epoxidized behenic acid amide, 1.0 part of anionic polyacrylamide, 0.1 part of polyamide polyamine epichlorohydrin, and 0.5 parts of cationic polyacrylamide, all in an absolutely dry mass ratio to pulp. Then, it was weighed with a Fourdrinier paper machine to make 170 g / m ² of base paper.

In order to adjust the surface size of the base paper, a 4% aqueous solution of polyvinyl alcohol was added to the optical brightener (Whit
ex BB, manufactured by Sumitomo Chemical Co., Ltd.) was added at 0.04%, the base paper was impregnated with this so as to have an absolute dry weight of 0.5 g / m ² , dried, and then calendered. Then, a base paper having a density adjusted to 1.05 was obtained.

Corona discharge treatment was applied to the wire side (this side is called the "reverse side") side of the obtained base paper, and then high density polyethylene was coated to a thickness of 23 μm using a melt extruder. Then, a resin layer made of a matte surface was formed (hereinafter, the resin layer surface is referred to as a “rear surface”). The resin layer on the back surface side is further subjected to corona discharge treatment, and thereafter, aluminum oxide (alumina sol 10 is used as an antistatic agent).
0, Nissan Chemical Industries, Ltd.) and silicon dioxide (Snowtex O, Nissan Chemical Industries, Ltd.) were dispersed in water at a ratio of 1: 2 (mass ratio) to obtain a dry mass of 0. .2 g /
It was applied so as to be m ² .

Further, after performing corona discharge treatment on the felt side (this side is called the "front side") side of the base paper having the resin layer formed on the back side, anatase type titanium dioxide 10%,
Trace amount of ultramarine and optical brightener (white flow PSN:
Sumitomo Chemical Co., Ltd.) MFR (melt flow rate, JIS K 721) containing 0.01% (to polyethylene)
Measured by the method described in No. 0, test temperature: 190 ° C., test load 2.16 Kg) of low density polyethylene of 3.8,
Using a melt extruder, coating was performed to a thickness of 24 μm to form a glossy thermoplastic resin layer. In this way, a support A having resin layers formed on the front and back sides of the base paper was produced.

—Preparation of Coating Solution for Coloring Material Receiving Layer— Silica fine particles were mixed with ion-exchanged water, diallylmonomethylammonium chloride was further mixed, and 500 using Nanomizer LA31 (manufactured by Nanomizer Co., Ltd.).
After being treated twice at a pressure of 0 Pa (500 kg / m ² ), the mixture was stirred for 60 minutes, and a 7% aqueous solution of PVA having the saponification degree shown below was added with stirring to give a color of the following composition having a pH of 3.5. A coating liquid A for the material receiving layer was prepared.

[Composition of Coating Material A for Coloring Material Receiving Layer] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, Ltd.) Tokuyama) Ion-exchanged water: 60.95 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nittobo Co., Ltd., solid content concentration) : 60%) PVA 7% aqueous solution (water-soluble resin) ... 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree 98.5%, polymerization degree 2400) Emulgen 109P 10% aqueous solution ... 1. 0 parts (Kao Corporation, nonionic surfactant) Diethylene glycol monobutyl ether ・ ・ ・ 0.30 parts

[Composition of Crosslinking Agent Mordant Mixing Solution A] A liquid (crosslinking agent mordant mixed solution A) containing a crosslinking agent and a mordant having the following composition was prepared. Titanium lactate: 7.1 parts (trade name: ORGATICS TC315 42% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) Ion-exchanged water: 68.9 parts Polyallylamine (10%) aqueous solution: 20 parts (PAA-10C, Nitto Boseki Co., Ltd., weight average molecular weight: 15000) Emulgen 109P 10% aqueous solution ... 4 parts (Kao Co., Ltd. nonionic surfactant)

-Preparation of Inkjet Recording Sheet- The coating material A for the colorant receiving layer is applied on the surface of the support at an application amount of 180 g / m ² using an extrusion die coater (application step), 80 ° C with hot air dryer
The solid content concentration of the coating layer was 20 at (wind speed of 3 to 8 m / sec).
% To dryness. The coating layer showed a constant drying rate during this period. Immediately thereafter, the cross-linking agent mordant mixed solution A
20 g / m ² was adhered to the coating layer by applying it for 30 seconds (step of applying the cross-linking agent mordant mixed solution A), and further dried at 80 ° C. for 10 minutes (drying step). In this way, the inkjet recording sheet (1) of the present invention was prepared in which the coloring material receiving layer having a dry film thickness of 32 μm was provided on the surface of the support.

(Example 2) The coating solution A for the colorant receiving layer used in Example 1 was mixed with the coating solution B for the colorant receiving layer having the following composition containing a crosslinking agent, and the crosslinking agent mordant mixed solution A was added as follows. An inkjet recording sheet (2) of the present invention was produced in the same manner as in Example 1 except that the mordant solution B having the composition was changed.

[Composition of Coating Liquid B for Coloring Material Receiving Layer] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, ) Tokuyama) Ion-exchanged water: 57.35 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content) Concentration: 60%) Titanium lactate: 3.6 parts (trade name: Organix TC315, 42% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) PVA 7% aqueous solution (water-soluble resin): 28.0 parts ( PVA124, manufactured by Kuraray Co., Ltd., saponification degree: 98.5%, polymerization degree: 2400) Emulgen 109P 10% aqueous solution: 1.0 part (Kao Corporation: nonionic surfactant) diethylene glycol Over mono-butyl ether ... 0.30 parts

[0115]   [Composition of mordant solution B]   Deionized water: 76 parts   Polyallylamine (10%) aqueous solution ・ ・ ・ 20 parts       (PAA-10C, Nitto Boseki Co., Ltd., weight average molecular weight: 15000)   Emulgen 109P 10% aqueous solution ・ ・ ・ 4 parts       (Nonionic surfactant manufactured by Kao Corporation)

(Example 3) The present invention was carried out in the same manner as in Example 2 except that the colorant-receptive layer coating solution B used in Example 2 was changed to the colorant-receptive layer coating solution C having the following composition. An inkjet recording sheet (3) was produced.

[Composition of Colorant Receiving Layer Coating Solution C] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, Ltd.) Tokuyama) Deionized water: 58.95 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) Zirconyl acetic acid: 2.0 parts (trade name: Organix ZB-115, 30% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) PVA 7% aqueous solution (water-soluble resin): 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree: 98.5%, polymerization degree: 2400) Emulgen 109P 10% aqueous solution: 1.0 part (Kao Co., Ltd., nonionic surfactant) Diethylene Recall mono-butyl ether ... 0.30 parts

(Example 4) The present invention was carried out in the same manner as in Example 2 except that the coating material B for the color material receiving layer used in the example 2 was changed to the coating material D for the color material receiving layer having the following composition. An inkjet recording sheet (4) was produced.

[Composition of Coating Solution B for Coloring Material Receiving Layer] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, Ltd.) Deionized water: 55.95 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) Zirconyl acetic acid ... 5.0 parts (trade name: Organix ZB-115, 30% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) PVA 7% aqueous solution (water-soluble resin) ... 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree: 98.5%, polymerization degree: 2400) Emulgen 109P 10% aqueous solution: 1.0 part (Kao Co., Ltd., nonionic surfactant) Diethylene Recall mono-butyl ether ... 0.30 parts

(Example 5) The present invention was carried out in the same manner as in Example 2 except that the coloring material receiving layer coating solution B used in Example 2 was changed to the coloring material receiving layer coating solution E having the following composition. An inkjet recording sheet (5) was produced.

[Composition of Colorant Receptive Layer Coating Liquid E] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, Ltd.) Tokuyama) Ion-exchanged water: 44.25 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) Zirconyl acetic acid: 16.7 parts (trade name: Organix ZB-115, 30% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) PVA 7% aqueous solution (water-soluble resin): 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree: 98.5%, polymerization degree: 2400) Emulgen 109P 10% aqueous solution: 1.0 part (Kao Co., Ltd., nonionic surfactant) Diethyle Glycol mono-butyl ether ... 0.30 parts

(Example 6) The present invention was carried out in the same manner as in Example 2 except that the coating solution B for the color material receiving layer used in Example 2 was changed to the coating solution F for the color material receiving layer having the following composition. An inkjet recording sheet (6) was produced.

[Composition of Colorant Receptive Layer Coating Liquid F] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, Ltd.) Deionized water: 59.8 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) Zirconyl acetic acid: 0.83 parts (trade name: Organix ZB-115, 30% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) PVA 7% aqueous solution (water-soluble resin): 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree: 98.5%, polymerization degree: 2400) Boric acid: 0.35 parts Emulgen 109P 10% aqueous solution :: 1.0 part (Kao Corporation: Nonion Surfactant) Diethylene glycol monobutyl ether ... 0.30 parts

(Example 7) The present invention was carried out in the same manner as in Example 2 except that the coating solution B for the colorant receiving layer used in Example 2 was changed to the coating solution G for the colorant receiving layer having the following composition. An inkjet recording sheet (7) was produced.

[Composition of Colorant Receptive Layer Coating Solution G] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 300 m ² / g, trade name: QS-30, Ltd.) Deionized water: 55.95 parts Diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) Zirconyl acetic acid: 5.0 parts (trade name: Organix ZB-115, 30% aqueous solution, manufactured by Matsumoto Pharmaceutical Co., Ltd.) Acetoacetyl-modified PVA 7% aqueous solution (water-soluble resin): 28 0.0 part (Gosephimmer Z-200H, manufactured by Nippon Synthetic Chemical Industry, degree of saponification 99%, degree of polymerization 2400) Emulgen 109P 10% aqueous solution ... 1.0 part (Kao Corporation, No On surfactant) Diethylene glycol monobutyl ether ... 0.30 parts

(Comparative Example 1) A comparative ink jet was prepared in the same manner as in Example 2 except that the coating material B for the colorant receiving layer used in Example 2 was changed to the coating solution H for the colorant receiving layer having the following composition. A recording sheet (8) was produced.

[Composition of Coating Solution H for Coloring Material Receiving Layer] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 130 m ² / g, trade name: Aerosil 130, Nippon Aerosil Co., Ltd. )) Ion-exchanged water: 60.35 parts diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) Boric acid: 0.6 parts PVA 7% aqueous solution (water-soluble resin): 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree: 98.5%, polymerization degree: 2400) 109P 10% aqueous solution: 1.0 part (Kao Corporation, nonionic surfactant) Diethylene glycol monobutyl ether: 0.30 part

Comparative Example 2 The coating solution A for the colorant receiving layer used in Example 1 was mixed with the coating solution I for the colorant receiving layer having the following composition, and the crosslinking agent mordant mixed solution A was mixed with the crosslinking agent mordant having the following composition. A comparative inkjet recording sheet (9) was produced in the same manner as in Example 1 except that the solution C was used.

[Composition of Colorant Receptor Layer Coating Liquid I] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area according to BET method: 130 m ² / g, trade name: Aerosil 130, Nippon Aerosil Co., Ltd. )) Ion-exchanged water: 60.95 parts diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) PVA 7% aqueous solution (water-soluble resin) ... 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree 98.5%, polymerization degree 2400) Emulgen 109P 10% aqueous solution ... 1. 0 parts (Kao Corporation, nonionic surfactant) Diethylene glycol monobutyl ether ・ ・ ・ 0.30 parts

[0130]   [Composition of cross-linking agent mordant mixed solution C]   Boric acid: 3 parts   Deionized water: 73 parts   Polyallylamine (10%) aqueous solution ・ ・ ・ 20 parts       (PAA-10C, Nitto Boseki Co., Ltd., weight average molecular weight: 15000)   Emulgen 109P 10% aqueous solution ・ ・ ・ 4 parts       (Nonionic surfactant manufactured by Kao Corporation)

(Comparative Example 3) Coating solution A for coloring material receiving layer used in Example 1 was mixed with coating solution J for coloring material receiving layer having the following composition, and crosslinking agent mordant mixed solution A was mixed with the above crosslinking agent mordant. A comparative inkjet recording sheet (10) was produced in the same manner as in Example 1 except that the solution C was used.

[Composition of Colorant Receptor Layer Coating Liquid J] Silica fine particles (inorganic pigment fine particles) 9.0 parts (specific surface area by BET method: 200 m ² / g, trade name: Aerosil 200, Nippon Aerosil Co., Ltd. )) Ion-exchanged water: 60.95 parts diallylmonomethylammonium chloride: 0.75 parts (trade name: PAS-M-1, weight average molecular weight: 20000, manufactured by Nitto Boseki Co., Ltd., solid content concentration) : 60%) PVA 7% aqueous solution (water-soluble resin) ... 28.0 parts (PVA124, manufactured by Kuraray Co., Ltd., saponification degree 98.5%, polymerization degree 2400) Emulgen 109P 10% aqueous solution ... 1. 0 parts (Kao Corporation, nonionic surfactant) Diethylene glycol monobutyl ether ・ ・ ・ 0.30 parts

(Comparative Example 4) An ink jet recording sheet of the present invention was prepared in the same manner as Comparative Example 2 except that the cross-linking agent mordant mixed solution C used in Comparative Example 2 was changed to the cross-linking agent mordant mixed solution D having the following composition. (11) was produced.

[0134]   [Composition of cross-linking agent mordant mixed solution D]   Boric acid: 3 parts   Deionized water: 88 parts   Diallyl monomethyl ammonium chloride ・ ・ ・ 5 parts       (Brand name: PAS-M-1, weight average molecular weight: 20,000,         Nittobo Co., Ltd., solid content concentration: 60%)   Emulgen 109P 10% aqueous solution ・ ・ ・ 4 parts       (Nonionic surfactant manufactured by Kao Corporation)

<Performance Evaluation> The inkjet recording sheets (1) to (7) of the present invention and the inkjet recording sheets (8) to (11) of the comparative examples obtained above were evaluated as follows. It was The evaluation results are shown in Table 1 below. (Glossiness) The 60 ° glossiness on the surface of the color material receiving layer of the recording sheet before printing is measured by a digital variable angle glossiness meter (UGV-
It was measured with 50DP, manufactured by Suga Test Instruments Co., Ltd.

(Ink Absorption Rate) Using an inkjet printer (PM-770C, manufactured by Seiko Epson Corp.), Y (yellow), M (magenta), C (cyan) on the color material receiving layer of each recording sheet. , K (black), B (blue), G
Print solid images of (green) and R (red), and then (about 1
After 0 seconds), a paper was contacted and pressed on the image, and the degree of transfer of the ink to the paper was evaluated according to the following criteria. [Standard] AA: No transfer of ink onto the paper was observed. BB: Partial transfer of the ink onto the paper was observed.

(Bleeding over time) On each ink jet recording sheet, a grid-like linear pattern (black line width 0.28 m) in which magenta ink and black ink were placed next to each other using the same printer for measuring the ink absorption rate.
m) was printed. After leaving for 3 hours after printing, it was stored in a thermo-hygrostat at 40 ° C. and a relative humidity of 90% for 3 days, and the line width of the black portion was measured and displayed as% over time. still,
The larger the value, the greater the blurring over time.

(Curl (Incurl)) The ink jet recording sheet was cut into A6 size and left on a flat test plate for 1 hour in an environment of 10 ° C. and 20% relative humidity. The height of the test plate was measured, and the average of the heights was used as the curl value.

(Crack of Coloring Material Receiving Layer) The surface condition of the coloring material receiving layer of each ink jet recording sheet was visually observed, and the presence or absence of cracking on the surface and the size thereof were evaluated according to the following criteria. [Criteria] ◯: No cracks were observed at all, which was good. Δ: A crack having a length of about 1 to 2 mm was recognized. X: A crack having a length of 3 mm or more was remarkably observed.

[0140]

[Table 1]

The results shown in Table 1 above show that the ink jet recording sheets of Examples 1 to 7 containing a compound of Group 4 element of the periodic table as a cross-linking agent have high gloss and ink absorbability, and have bleeding and curling over time. It shows that there is little cracking and that it is strong without cracks. On the other hand, the inkjet recording sheets of Comparative Examples 1 to 4 containing boric acid as a crosslinking agent did not have sufficient gloss and were poor in ink absorbability, as compared with the inkjet recording sheets of Examples 1 to 7 above. However, bleeding and curling increased over time, and cracking also occurred.

[0142]

EFFECTS OF THE INVENTION According to the present invention, an image having a high gloss on the recording surface, excellent ink absorbency, high resolution and high density can be obtained, and after printing, it is stored for a long time in a high temperature and high humidity environment In this case, it is possible to provide an ink jet recording sheet that can stably hold an image without causing bleeding over time and has less curl and excellent printer transportability.

Continued front page    F-term (reference) 2C056 EA13 FC06                 2H086 BA01 BA15 BA19 BA31 BA33                       BA35 BA37 BA48

Claims (6)

[Claims] 1. A coloring material having a three-dimensional network structure, which comprises, on a support, inorganic pigment fine particles, a water-soluble resin, a crosslinking agent capable of crosslinking the water-soluble resin, and a basic organic cation mordant. An inkjet recording sheet provided with a receiving layer, wherein the cross-linking agent is a compound of Group 4 element of the periodic table. 2. The ink jet recording sheet according to claim 1, wherein the water-soluble resin is polyvinyl alcohol and the crosslinking agent is a zirconium compound. 3. The inorganic pigment fine particles are based on the BET method.
Specific surface area is 200m ²/ G or more of vapor phase silica fine particles
The ink jet ink according to claim 1 or 2, wherein
Sheet for recording. 4. The ink jet recording sheet according to claim 1, wherein the basic organic cation mordant is polyallylamine. 5. The ink jet recording sheet according to claim 1, wherein the cross-linking agent further contains a boron compound. 6. The ink jet recording sheet according to claim 1, wherein the color material receiving layer is provided on a thermoplastic resin layer.