JP2003191627A - Ink jet recording sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording sheet with a good plane state after a drying process without deteriorating acceptability of other ink. <P>SOLUTION: The ink jet recording sheet has a coloring material accepting layer on a base material. The coloring material accepting layer contains a telomer-type fluorine-based surface-active agent. Preferably, the coloring material accepting layer is formed by further applying first paint including inorganic particulates, a water-soluble resin and a cross-linking agent including a boron compound, and second paint capable of cross-linking the water-soluble resin. The second paint is basic and in addition contains a silicone-based surface-active agent. <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 an inkjet recording sheet, and more particularly to an inkjet recording sheet having an excellent appearance (planar state).

[0002]

2. Description of the Related Art In recent years, 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
It has been widely used not only in offices but also in so-called home use because it can be recorded on various recording materials, its hardware (device) is relatively inexpensive, it is compact, and it has excellent quietness. ing.

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 (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) Good light resistance and water resistance of the printed area thing,
(8) High whiteness of the recording sheet, (9) Good storability of the recording sheet (no yellowing coloring during long-term storage, no image bleeding during long-term storage), (10)
It is difficult to deform, has good dimensional stability (curl is sufficiently small), and (11) has good hard running property. In addition to the above characteristics, the photo glossy paper used for the purpose of obtaining a so-called photograph-like high-quality recorded matter may have glossiness, surface smoothness, and a photographic paper-like texture similar to silver salt photographs. Required.

Recording sheets used for ink jet recording are, for example, JP-A-55-51583, JP-A-55-144172, and JP-A-55-15039.
5 gazette, the same 56-148582 gazette, the same 56-14.
No. 8583, No. 56-148584, No. 56
-148585, 57-14091, 57-38185, 57-129778, 57-129979, 60-21908.
There is known one in which a pigment such as silica and a water-soluble binder are coated on a support such as paper or plastic film, as described in JP-A No. 4 and JP-A No. 60-245588.
However, all of these proposed recording sheets have very low glossiness, which is insufficient for use as a photo glossy paper.

Further, JP-A-2-276670, JP-A-3-215082, JP-A-3-281383,
JP-A 6-199035 and the like propose a recording sheet using a pseudo-boehmite sol and a water-soluble binder. These recording sheets satisfy some required properties in terms of glossiness, but have problems such as high production cost of pseudo-boehmite particles and difficulty in preparing a coating solution.

In JP-A-4-223190, 5-20 g / m ² of synthetic silica and polyvinyl alcohol (PVA) are added to a base paper coated with 0.1 g / m ² or more of borax or boric acid. An inkjet recording sheet provided with a recording layer made of is proposed. The above-mentioned technique is merely aimed at improving the coating film strength of the recording layer having a small binder content, and is inferior in terms of gloss, and is insufficient for use as a photo-glossy paper.

Further, recording materials using various water-soluble polymers for obtaining gloss have been proposed. For example, JP-A-58-89391, JP-A-58-134784, JP-A-58-134786, and JP-A-60-44386.
No. 60-132785, No. 60-145.
879, 60-168651, 60-
Known are those in which polyvinyl alcohol, polyvinylpyrrolidone, gelatin and the like described in Japanese Patent Nos. 171143 and 60-171143 are coated on a support such as paper or plastic film. These recording sheets are also excellent in glossiness, but inferior in ink quick drying property,
It was insufficient for photo glossy paper.

On the other hand, JP-A-7-276789 and JP-A-8-174992 propose an ink jet recording sheet satisfying the required characteristics and manufacturing cost of the above ink jet recording sheet. JP-A-7-
JP-A-276789 proposes a recording sheet in which a coloring material receiving layer having a three-dimensional structure having a high porosity, which is formed of fine particles of an inorganic pigment and a water-soluble resin, is provided on a support. According to this configuration, the ink absorbency is improved, color blurring during printing is sufficiently suppressed, and an image with high resolution can be obtained. This color material receiving layer can be generally formed by containing a large amount of particles having a small particle diameter, but since the binder amount for layer formation needs to be reduced so that voids can be formed, the coating layer is rapidly dried. If so, there is a defect that cracks occur and the transparency and appearance of the colorant receiving layer are impaired.

As a method for preventing the ink receiving layer from cracking, Japanese Patent Application Laid-Open No. 9-109545 proposes a method in which the viscosity of the binder of the coating liquid is made relatively high, but this method reduces the workability. There is a risk of uneven coating and uneven coating, and it has not reached a level that is practically effective. Further, Japanese Patent Laid-Open No. 7-76161 and 10-
Japanese Patent No. 119423 discloses a method for preventing cracks using a coating liquid composed of inorganic particles, polyvinyl alcohol (PVA), boric acid or borate, but in the case of this method, the viscosity of the coating liquid increases and workability is improved. Is large, and there is a problem in the stability of the liquid over time, and it has not reached a practically effective level.

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. . However, these recording sheets have excellent ink absorbability due to their constitution, have high ink receptivity capable of forming a high-resolution image, and show high gloss, but after printing, they are exposed to a high temperature and high humidity environment for a long time. When stored for a time, there is a problem that the solvent diffuses together with the dye in the color material-receptive layer to cause image bleeding with time (so-called “aging bleeding”).

On the other hand, with respect to the fading (image storability) of the formed image, the image stabilization has been attempted from the viewpoints of light resistance, water resistance, heat resistance, etc. as described above, but in addition to this, In recent years, it has been found that an image after printing is discolored by air, particularly ozone, and stability against ozone in the air has become a particular problem. Therefore, there is a demand for image storage performance that is capable of storing images stably for a long period of time without damaging the coloring and density at the time of printing, because it has the property that ozone in the air does not fade (ozone resistance). high. Techniques for improving ozone resistance include, for example, JP-A-7-26689 and JP-A-2000-17723.
Although disclosed in Japanese Patent Laid-Open No. 5-5, in each case, although some ozone resistance is obtained, the improvement in ozone resistance and the improvement in other ink receiving performance such as water resistance and ink blurring are simultaneously satisfied. It is not possible.

Further, depending on the chemicals to be added to the color material receiving layer, the adhesion between the inorganic pigment fine particles and the water-soluble resin may be hindered or the adhesion between the color material receiving layer and the support may be hindered. There is. Therefore, the film strength of the color material receiving layer is lowered, and the color material receiving layer is peeled off from the support when the sheet is bent or torn, and there is a problem in handleability. Thus, there is still room for improvement from the viewpoint of improving the handleability of the inkjet recording sheet.

In order to solve these various problems, Japanese Patent Application No. 20
No. 00-324248, a mordant is introduced in the process of applying a crosslinking agent solution to the coloring material receiving layer, that is, the coloring material receiving layer contains a coloring material receiving layer containing inorganic pigment fine particles and a water-soluble resin. A solution containing a cross-linking agent capable of cross-linking a water-soluble resin and a mordant is applied to the coating layer at the same time as the coating or during the drying of the formed coating layer, and then the solution is applied. Method of cross-linking and curing the coating layer provided with (W
The et On Wet method, hereinafter referred to as the WOW method. ) Is proposed.

The WOW method has an excellent appearance with no cracks in the image-receiving layer, and a cross-linking agent solution containing optional additives such as a mordant, an anti-fading agent (to improve light resistance and ozone resistance), and a pH adjuster on the paper surface. However, when the cross-linking agent solution is applied after the color-material receiving layer coating solution is applied, the cross-linking agent solution is repelled by the color-material receiving layer coating solution and there is a problem of repellency failure. .

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems in the prior art and to provide an ink jet recording sheet having a good appearance (planar shape) without causing a repellant failure even by the WOW method. And

[0016]

Means for solving the problems Means for solving the above problems are as follows. That is,

<1> An ink jet recording sheet having a color material receiving layer on a support, characterized in that the color material receiving layer contains a telomer type fluorochemical surfactant. is there.

<2> The ink jet recording sheet according to <1>, wherein the color material receiving layer further contains inorganic pigment fine particles, a water-soluble resin, and a boron compound crosslinking agent.

<3> The coloring material receiving layer is an inorganic fine particle,
<1> formed by applying a first coating liquid containing a water-soluble resin and a crosslinking agent, and a second coating liquid capable of crosslinking the water-soluble resin
Alternatively, the inkjet recording sheet according to <2>.

<4> The second coating liquid is basic,
The above <3 containing a telomer type fluorosurfactant
The inkjet recording sheet according to the above item>.

<5> The second coating liquid is applied while the coating layer formed by applying the first coating liquid is being dried and before the coating layer exhibits a decreasing rate of drying. The inkjet recording sheet according to <3> or <4>, which is obtained by crosslinking and curing the coating layer.

<6> The inkjet recording sheet according to any one of <2> to <5>, wherein the inorganic pigment fine particles are gas phase silica having an average primary particle diameter of 20 nm or less.

<7> For ink jet recording according to any one of <2> to <6>, wherein the water-soluble resin is polyvinyl alcohol and / or modified polyvinyl alcohol and the crosslinking agent is a boron compound. It is a sheet.

<8> The basic solution of the second coating solution is p
The inkjet recording sheet according to any one of <4> to <7>, wherein H is 8.0 or more.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION << Inkjet recording sheet >>
The ink jet recording sheet of the present invention is characterized by having a coloring material receiving layer on a support and containing a telomer type fluorochemical surfactant in the coloring material receiving layer, preferably the coloring material receiving layer. Further coating a first coating liquid containing a cross-linking agent containing inorganic fine particles, a water-soluble resin and a boron compound, and a second coating liquid capable of crosslinking the water-soluble resin,
An ink jet recording sheet in which the coating liquid is basic and contains a telomer type fluorochemical surfactant. Hereinafter, the inkjet recording sheet of the present invention will be described.

<Coloring Material Receiving Layer> The coloring material receiving layer in the present invention contains the telomer type fluorochemical surfactant as described above, and further, the inorganic pigment fine particles, the water-soluble resin, and the above water-soluble resin are cross-linked. It is preferable that the compound contains a boron compound cross-linking agent, a mordant and the like. Further, as described below, the color material receiving layer is preferably formed on the support by the WOW method.

(Surfactant) In the present invention, for the purpose of preventing the repelling failure of the basic solution as the second coating liquid,
Telomer type fluorochemical surfactant (hereinafter,
It may be referred to as the "surfactant in the present invention". )including. Although the reason for preventing the repellency failure is not clear, it is considered that this surfactant moderately controls the crosslinking rate and the wettability of the interface when the second coating liquid is applied.

The telomer type fluorochemical surfactant in the present invention is a surfactant obtained from a fluorochemical compound obtained by telomerization of tetrafluoroethylene, and is generally the following general formula 1 or general formula 2 Is a surfactant having a fluorinated alkyl group.

[0029]

[Chemical 1]

[0030]

[Chemical 2]

In the above formula, n represents an integer of 4 or more and m represents an integer of 1 or more.

Examples of the surfactant having such a group include a low molecular weight compound (also referred to as a linear type) and a high molecular weight compound (also referred to as a polymeric type) having these groups.

Examples of the low molecular weight compound include compounds represented by the following general formula.

[0034]

[Chemical 3]

In the above formula, Rf is a fluorinated alkyl chain, specifically, C ₁₀ F ₂₁ −, C ₈ F ₁₇ −, C ₆ F ₁₃ −, C
_{5 F ll -, C 4 F} 9 - , and the like. Examples of _{^{X l -OH, -O (CH 2}} CH 2 O) l -H, -SCH 2 CH 2
_{COO-M, -S0 3 -M,} -O-P (= O) (O
_{M) 2, -OCO-L-} COOM, -SO 2 NR 2 -CH 2
CH ₂ OH, such as -SO ^₂ NR ₂ -CH ₂ COOM and the like. In the above formula, 1 is an integer of 1 or more, M is a counter cation such as a hydrogen atom or a metal ion, R ² is an alkyl group, L is — (CH ₂ ) ₂ —, — (CH ₂ ) ₃ —, Represents orthophenylene, -CH = CH- and the like.

Examples of X ² include —OH, —NH—R ^{3 and the} like. R ³ is an alkyl group containing a hydrogen atom, an alkyl group, an ammonium group, and the like, for example, — (CH ₂ ) ₃ —
^{N + R 4 R 5 R 6} Y -, - (CH 2) 3 -N + R 4 R 5 R 7 COO
First class. Here, R ⁴ , R ⁵ , and R ⁶ are alkyl groups, aryl groups, and the like, R ⁷ is an alkylene group, and Y ⁻
Represents halogen or the like.

Examples of the high molecular compound include polymers obtained from the monomers represented by the following general formulas 5 to 6, and copolymers with monomers copolymerizable therewith.

[0038]

[Chemical 4]

[0039]

[Chemical 5]

In the above formula, Rf is the above-mentioned general formula 3 or general formula 4
Has the same meaning as in, R ¹ is hydrogen, a methyl group, or the like. R ² is an alkyl group or the like.

Further, as the monomer copolymerizable with these,
For example, (meth) acrylic acid, (meth) acrylic acid alkyl ester, [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, (meth) acrylic C-18 alkyl ester of (meth) acryleic acid such as acid hexyl, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate and stearyl (meth) acrylate. ], (Meta)
Acrylic acid cycloalkyl ester [eg (meth)
Cyclohexyl acrylate, norbornyl (meth) acrylate, etc. ], An aryl ester of (meth) acrylic acid [for example, phenyl (meth) acrylate and the like. ], Aralkyl ester [eg, benzyl (meth) acrylate, etc. ], A substituted (meth) acrylic acid alkyl ester [for example, 2-hydroxyethyl (meth) acrylate,
Dimethylaminoethyl (meth) acrylate etc. ],

(Meth) acrylic acid esters containing a polyether group, [eg diethylene glycol monomethyl ether mono (meth) acrylate, diethylene glycol monoethyl ether mono (meth) acrylate, dipropylene glycol monomethyl ether mono (meth) acrylate, Dipropylene glycol monoethyl ether mono (meth) acrylate, triethylene glycol monomethyl ether mono (meth) acrylate, triethylene glycol monoethyl ether mono (meth) acrylate, tripropylene glycol monomethyl ether mono (meth) acrylate, tripropylene glycol mono Ethyl ether mono (meth) acrylate, polyethylene glycol monomethyl ether mono (meth) acrylate , Polyethylene glycol monoethyl ether mono (meth) Akurirenito, polypropylene glycol monomethyl ether mono (meth) acrylate, polypropylene glycol monoethyl ether mono (meth) acrylate. ], (Meth) acrylamides [for example, (meth) acrylamide, dimethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide and the like. ], Aromatic vinyls [eg, styrene, vinyltoluene, α-methylstyrene, etc.]. ], Vinyl esters [eg, vinyl acetate, vinyl propionate, vinyl versatate, etc.]. ], Allyl esters [eg, allyl acetate, etc. ], A halogen-containing monomer [eg, vinylidene chloride, vinyl chloride, etc. ], Vinyl cyanide [eg (meth) acrylonitrile and the like. ], Olefins [eg, ethylene, propylene, etc. ] Is mentioned.

Specifically, Dainippon Ink and Chemicals, Inc.
Company MegaFac F470, MegaFac F472,
MegaFac F473, MegaFac F475, MegaFac F476, MegaFac F1405, MegaFac F178K, MegaFac F-140NK, DuPosi Zonyl FSP, FSE, TBS, F
S-62, FSA, FSO, FSN, FS-3
00, same FS-310, same FSN-100, same FSO-
100, DS101, DS202, D manufactured by Daikin Industries
S401 etc. are mentioned.

In the color material receiving layer, the total coating amount (solid content) of the surfactant in the present invention is 0.001 to
0.4 g / m ² is preferable, 0.005-0.2 g / m ²
Is more preferable, and 0.01 to 0.1 g / m ² is particularly preferable. When the coating amount is in the range of 0.001 to 0.4 g / m ² , the repelling failure can be effectively eliminated while maintaining the economical efficiency.

The coloring material receiving layer in the present invention has various known surfactants for the purpose of improving coating suitability and surface quality, and known ionic conductivity for the purpose of suppressing triboelectric charging and peeling charging of the surface. You may use surfactant etc. together with the surfactant in this invention.

(Inorganic Pigment Fine Particles) As described above, the colorant receiving layer in the present invention preferably has inorganic pigment fine particles. As the inorganic pigment fine particles, for example, 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 particularly preferable.

Since the above-mentioned 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. Therefore, if they are dispersed to an appropriate particle size, transparency is imparted to the receiving layer. It is possible to 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 diameter of the inorganic pigment fine particles is preferably 20 nm or less, more preferably 15 nm or less, and particularly preferably 10 nm or less.

The silica fine particles have a silanol group on the surface thereof, and the particles are easily attached to each other by hydrogen bond due to the silanol group, and the particles are attached to each other through the silanol group and the water-soluble resin. When the average primary particle size is 20 nm or less as described above, a structure having a high porosity and high transparency can be formed, and the ink absorption characteristics can be effectively improved.

The silica fine particles are roughly classified into wet method particles and dry method (gas phase method) particles depending on the 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 dry method (gas phase method)
Anhydrous silica by a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), by heating and reducing and vaporizing silica sand and coke with an arc in an electric furnace, and oxidizing this with air (arc method). The method of obtaining is the mainstream.

The hydrous silica (wet method) and anhydrous silica (dry method) obtained by these methods have different properties such as the density of silanol groups on the surface and the presence or absence of pores. Silica is particularly preferable because it is easy to form a three-dimensional structure having a particularly high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is as high as 5 to 8 / nm ² , and the silica fine particles are likely to densely aggregate (aggregate),
On the other hand, in the case of anhydrous silica, the density of the silanol groups on the surface of the fine particles is as few as 2-3 / nm ² , resulting in sparse soft flocculation, resulting in a structure with high porosity. It is estimated to be. Therefore, in the present invention, silica fine particles (anhydrous silica) obtained by the dry method (gas phase method) are preferable, and further silica fine particles having a silanol group density on the surface of the fine particles of 2 to 3 / nm ^2. It is preferable to use.

(Water-Soluble Resin) Similarly, the colorant receiving layer in the present invention preferably contains a water-soluble resin. Examples of the water-soluble resin include polyvinyl alcohol (PVA), cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, and cellulosic resin, which are resins having a hydroxyl group as a hydrophilic structural unit. Methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), etc.], chitins,
Chitosans, starch; polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PE), which are resins having ether bonds
G), polyvinyl ether (PVE); polyacrylamide (P which is a resin having an amide group or an amide bond)
AAM), polyvinylpyrrolidone (PVP) and the like. Also, having a carboxyl group as a dissociative group,
Examples thereof include polyacrylic acid salts, maleic acid resins, alginates and gelatins. Among the above, polyvinyl alcohols are particularly preferable.

The content of the above water-soluble resin is such that the decrease in film strength and cracking during drying due to the excessive content are prevented, and the voids are filled with the resin due to the excessive content. From the viewpoint of facilitating ease and preventing the ink absorbency from decreasing due to a decrease in porosity, it is preferably 9 to 40% by mass, and 12 to 33% by mass with respect to the total solid content of the coloring material receiving layer. More preferable.

The inorganic pigment fine particles and the water-soluble resin, which mainly constitute the colorant receiving layer, may be a single material or a mixture of a plurality of materials.

From the viewpoint of transparency, the type of resin combined with the silica fine particles is important. When the above anhydrous silica is used, polyvinyl alcohol (PVA) is preferable as the water-soluble resin, and the saponification degree is 70 to 9 among them.
More preferred is 9% PVA.

The PVA has a hydroxyl group in its structural unit, and the hydroxyl group and the silanol group on the surface of the silica fine particles form a hydrogen bond to form a three-dimensional network structure in which the secondary particles of the silica fine particles are chain units. Make it easier to form. It is considered that the formation of the above-mentioned three-dimensional network structure makes it possible to form a coloring material receiving layer having a porous structure with a high porosity. In inkjet recording, the porous coloring material-receiving layer obtained as described above can rapidly absorb ink by a capillary phenomenon and form dots with good circularity without ink blurring.

-Content ratio of inorganic pigment fine particles and water-soluble resin-Content ratio of inorganic pigment fine particles (preferably silica fine particles; i) and water-soluble resin (p) [PB ratio (i: p), water-soluble resin] The mass of the inorganic pigment fine particles relative to 1 part by mass] 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)
As a result, it is possible to prevent a decrease in film strength and a crack during drying due to the PB ratio being too large.
If the B ratio is too small, the voids are more likely to be blocked by the resin, and from the viewpoint of preventing the ink absorptivity from decreasing due to the reduction of the void ratio, 1.5: 1 to 1: 1.
0: 1 is preferred.

Since the recording sheet may be stressed when passing through the transport system of the ink jet printer, it is necessary that the coloring material receiving layer has 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, anhydrous silica fine particles having an average primary particle diameter of 20 nm or less and a water-soluble resin have a PB ratio of 2: 1 to 5:
In 1, use a high-pressure homogenizer, sand grinder, colloid mill, dyno mill, ultrasonic disperser, thin-film rotation type high-speed mixer (Filmix), etc. to apply a sufficiently dispersed coating solution onto a support, and apply the coating solution. When the layer is dried, a three-dimensional network structure having secondary particles of silica fine particles as a chain unit is formed, the average pore diameter is 30 nm or less, the porosity is 50% to 80%, and the pore specific volume is 0.5 ml / g. that's all,
It is possible to easily form a translucent porous film having a specific surface area of 100 m ² / g or more.

(Crosslinking Agent) The colorant receiving layer of the ink jet recording sheet of the present invention preferably further contains a crosslinking agent in the coating layer (porous layer) containing the inorganic pigment fine particles and the water-soluble resin. It is preferably a layer cured by a crosslinking reaction between the agent and the water-soluble resin.

(Crosslinking Agent Used in First Coating Liquid) Water-Solubility
As a cross-linking agent capable of cross-linking the resin, it is not used in the colorant receiving layer.
Select a suitable one in relation to the water-soluble resin
However, in particular, the boron compound is used because of its rapid crosslinking reaction.
Preferred are, for example, borax, boric acid, borate (eg
For example, orthoborate, InBO₃, ScBO₃, YBO
₃, LaBO₃, Mg₃(BO₃) ₂, Co₃(BO₃)₂, Nihou
Acid salts (eg Mg₂B₂O_Five, Co₂B₂O_Five), Metahou
Acid salts (eg LiBO₂, Ca (BO₂)₂, NaBO₂,
KBO₂), Tetraborate (eg Na₂B_FourO₇・ 10H
₂O), pentaborate (eg KB_FiveO₈・ 4H ₂O, Ca
₂B₆O₁₁・ 7H₂O, CsB_FiveO_Five), Glyoxal,
Melamine formaldehyde (eg, methylol melamine)
Min, alkylated methylol melamine), methylol urine
Element, resole resin, polyisocyanate, epoxy resin
Etc. can be mentioned. Among them, the crosslinking reaction
Borax, boric acid, and borate are preferable from the viewpoint of causing
Uric acid is more preferable, and polyvinyl alcohol is used as the water-soluble resin.
Especially preferred is the use in combination with caul.

When gelatin is used as the water-soluble resin, the following compounds known as a gelatin hardener can be used as a crosslinking agent. 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, active halogen compounds such as 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N'-ethylenebis (vinylsulfonylaceta) Amide), active vinyl compounds such as 1,3,5-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. The crosslinking agents may be used alone or in combination of two or more.

(Crosslinking Agent Used in Second Coating Liquid) The application of the second coating liquid is performed by applying the coating liquid (first coating liquid) for forming the porous color material receiving layer. At the same time or first
It is preferable that the treatment is performed before the coating layer formed by applying the coating liquid 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 second coating liquid permeates into the coating layer at the same time as the coating liquid is coated, or before the coating layer starts to exhibit the decreasing rate of drying, and reacts rapidly with the water-soluble resin in the coating layer. By gelling (curing) the water-soluble resin, the film strength of the coating layer is immediately and significantly improved.

As the cross-linking agent contained in the second coating liquid, the same cross-linking agents as those exemplified in the first coating liquid are used. When polyvinyl alcohol is used as the water-soluble resin in the first coating liquid and boric acid is used as the crosslinking agent, the crosslinking reaction proceeds only by making the second coating liquid basic. A cross-linking agent may be added.

The second coating liquid is a mordant, a surfactant, and p.
It is prepared by dissolving an H-conditioning agent and, if necessary, a crosslinking agent in water and / or an organic solvent. The concentration of the crosslinking agent in the crosslinking agent solution is 0.05 to 10 with respect to the mass of the crosslinking agent solution.
Mass% is preferable and 0.1-7 mass% is especially preferable.
Water is generally used as the solvent constituting the second coating liquid, and may be an aqueous mixed solvent containing an organic solvent miscible with water. Any organic solvent can be used as long as it can dissolve the crosslinking agent, and examples thereof include alcohols such as methanol, ethanol, isopropyl alcohol and glycerin; ketones such as acetone and methyl ethyl ketone; methyl acetate and ethyl acetate. And the like; aromatic solvents such as toluene; ethers such as tetrahydrofuran; and halogenated carbon solvents such as dichloromethane.

(Mordant) In the present invention, a mordant is preferably contained in the colorant receiving layer from the viewpoint of further improving the water resistance of the formed image and the bleeding resistance with time. As the mordant, a cationic polymer (cationic mordant)
When it is present in the color material receiving layer, it can interact with a liquid ink having an anionic dye as a color material to stabilize the color material and improve water resistance and blurring over time.

However, when this is directly added to the coating solution for forming the color material receiving layer, there is a possibility that aggregation may occur with the inorganic pigment fine particles having anion charge such as silica, but If the method of preparing and applying as a separate solution of 1 is used, there is no need to worry about the aggregation of the inorganic pigment fine particles. Therefore, in the present invention, it is preferably contained in the second coating liquid for use.

As the cationic mordant, a polymer mordant having a primary to tertiary amino group or a quaternary ammonium group as a cationic group is preferably used, but a cationic non-polymer mordant is also used. can do. As the polymer mordant, first to third
A homopolymer of a monomer (mordant monomer) having a primary amino group and a salt thereof or a quaternary ammonium salt group, or a copolymerization weight of the mordant monomer and another monomer (hereinafter, referred to as "non-mordant polymer"). Those obtained as a polymer or a condensation polymer are preferable. Further, these polymer mordants can be used in the form of either a water-soluble polymer or water-dispersible latex particles.

Examples of the above-mentioned monomer (mordanting monomer) include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium. Chloride, N, N-dimethyl-N-ethyl-N-p-vinylbenzylammonium chloride,
N, N-diethyl-N-methyl-N-p-vinylbenzylammonium chloride, N, N-dimethyl-Nn
-Propyl-N-p-vinylbenzyl ammonium chloride, N, N-dimethyl-Nn-octyl-N-p
-Vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-benzyl-
N-p-vinylbenzylammonium chloride, N,
N-dimethyl-N- (4-methyl) benzyl-Np-
Vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-Np-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, trimethyl-2-
(Methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, triethyl-2- (acryloyloxy) ethylammonium chloride, trimethyl-3- (methacryloyl) Oxy)
Propyl ammonium chloride, triethyl-3-
(Methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl-2- (methacryloylamino) ethylammonium chloride, trimethyl-2- (acryloylamino) ethylammonium chloride, triethyl-2- (acryloyl) Amino) ethylammonium chloride, trimethyl-3-
(Methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride, triethyl-3- (acryloylamino) propylammonium chloride,

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride,
N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl-3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium Bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-
3- (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 non-mordanting polymer 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 inkjet ink. A monomer that does not show or has a substantially small interaction. Examples of the non-mordanting monomer include (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylate; (meth)
(Meth) acrylic acid aryl ester such as phenyl acrylate; aralkyl ester such as benzyl (meth) acrylate; aromatic vinyls such as styrene, vinyltoluene, α-methylstyrene; vinyl acetate, vinyl propionate, vinyl versatate And vinyl 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 (meth) alkyl group having 1 to 18 carbon atoms.
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 non-mordant monomers can be used alone or in combination of two or more.

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 preferably 1,000 to 200,000 in terms of weight average molecular weight. When the molecular weight is in the range of 1,000 to 200,000, the water resistance will not be insufficient, and the viscosity will be too high and the handling aptitude can be prevented from being lowered.

As the above cationic non-polymer mordant, water-soluble metal salts such as aluminum sulfate, aluminum chloride, polyaluminum chloride, magnesium chloride, zirconyl acetate and zirconyl oxychloride are preferable.

(Other Components) The colorant receiving layer may contain the following components, if necessary. For the purpose of suppressing the deterioration of the coloring material, various kinds of ultraviolet absorbers, antioxidants, and fading inhibitors such as singlet oxygen quencher may be contained. Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, benzotriazolylphenol derivatives and the like. 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, a phenol derivative in which at least one of 2-position or 6-position is substituted with a branched alkyl group is preferable.

Further, benzotriazole type ultraviolet absorbers, salicylic acid type ultraviolet absorbers, cyanoacrylate type ultraviolet absorbers, oxalic acid anilide type ultraviolet absorbers and the like can also be used. For example, JP-A-47-1053
No. 7, gazette 58-111942 gazette, gazette 58-21.
No. 2844, No. 59-19945, No. 59-
46646, 59-109055, and 6
No. 3-53544, Japanese Patent Publication No. 36-10466, No. 42-26187, No. 48-30492, No. 48-31255, No. 48-41572.
JP-A-48-54965 and JP-A-50-1072.
No. 6, gazettes, US Pat. Nos. 2,719,086, 3,707,375, 3,754,919, 4,220,711, etc. There is.

A fluorescent whitening agent can also be used as an ultraviolet absorber, and examples thereof include a coumarin-based fluorescent whitening agent. Specifically, JP-B-45-4699 and 54-53.
No. 24, etc.

Examples of the above-mentioned 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 anti-fading agents may be used alone or in combination of two or more kinds. This anti-fading agent is water-soluble,
It may be dispersed or emulsified, or may be contained in microcapsules. The amount of the anti-fading agent added is preferably 0.01 to 10% by mass of the coating material for the colorant receiving layer.

Further, for the purpose of enhancing the dispersibility of the fine particles of the inorganic pigment, various inorganic salts and an acid, an alkali or the like as a pH adjusting agent may be contained. Further, metal oxide fine particles having electronic conductivity may be included for the purpose of suppressing frictional electrification and peeling electrification on the surface, and various matting agents may be included for the purpose of reducing the frictional property of the surface.

(Preparation of Inkjet Recording Sheet: W
(OW method) As described above, it is preferable that a mordant is introduced into the coloring material receiving layer in the process of applying the second coating liquid. That is, the coloring material receiving layer is formed by applying a coloring material receiving layer coating liquid (first coating liquid) containing inorganic pigment fine particles having an average primary particle diameter of 20 nm or less, a water-soluble resin, and a crosslinking agent, and applying the coating liquid. A basic coating liquid (second coating liquid) capable of cross-linking a water-soluble resin is applied to the coating layer during the drying of the coating layer formed before and before the coating layer shows a decreasing rate of drying. After applying, a method of crosslinking and curing the coating layer applied with the solution (W
It is preferably formed by the OW method). Here, the surfactant in the present invention is preferably contained in the basic coating liquid (second coating liquid).

As described above, in the present invention, both the cross-linking agent and the water-soluble resin are included in the first coating liquid, and the basic coating liquid (second coating liquid) is applied during the drying of the first coating liquid. Thus, the appearance such as cracks and repellency failure can be improved.

In the present invention, the coating liquid containing the inorganic pigment fine particles as the first coating liquid, the water-soluble resin and the boron compound crosslinking agent can be prepared, for example, 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 rotary wet colloid mill (for example, CLEARMIX (manufactured by M Technique Co., Ltd.)) is used. , For example 10000 rpm
After dispersing for 20 minutes (preferably 10 to 30 minutes) under the condition of high speed rotation (preferably 5000 to 20000 rpm), a boron compound cross-linking agent (for example, 0.5% of silica) is used.
˜20% by mass), and disperse under the same conditions as above to obtain an aqueous polyvinyl alcohol solution (for example, 1% of silica).
It can be prepared by adding (so that PVA has a mass of about / 3) and further performing dispersion under the same rotation conditions as 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. If necessary, a pH adjuster, a dispersant, a surfactant, an antifoaming agent, an antistatic agent, etc. may be added to the first coating liquid.

In the present invention, the coating liquid containing the surfactant of the present invention, which is the second coating liquid, can be prepared, for example, as follows. Ion-exchanged water with mordant
(0.1 to 5.0% by mass), the surfactant of the present invention (0.0
1 to 1.0% by mass) and, if necessary, a crosslinking agent (0 to 5.0% by mass) and sufficiently stirred. The pH of the second coating liquid is preferably 8.0 or higher, and in order to adjust the pH to 8.0 or higher, aqueous ammonia, sodium hydroxide, calcium hydroxide, amino group-containing compounds (ethylamine, ethanolamine, diethanolamine, It is preferable to adjust the pH with, for example, polyallylamine.

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

After applying the first coating liquid, the second coating liquid is applied to the coating layer, and the second coating liquid is applied before the coating layer after application shows a decreasing rate of drying. It is preferable to add. That is, after the application of the first coating liquid, the second coating liquid is preferably introduced by introducing the second coating liquid while the coating layer exhibits the constant rate of drying.

Here, "before the coating layer starts to exhibit the decreasing rate of drying" usually means a few minutes immediately after the coating of the first coating liquid, and during this period, the coating layer The constant rate drying rate, which is a phenomenon in which the content of the solvent decreases in proportion to time, is shown. Regarding the time showing the constant rate drying rate,
Chemical Engineering Handbook (p.707-712, published by Maruzen Co., Ltd.)
(October 25, 1980).

As described above, after the application of the first coating liquid, the coating layer is dried until it exhibits the rate of decrease in drying rate.
The drying is generally performed at 50 to 180 ° C. for 0.5 to 10 minutes (preferably 0.5 to 5 minutes). As the drying time, it naturally depends on the coating amount, but the above range is suitable.

As a method of applying before the above-mentioned coating layer shows a decreasing rate of drying, (1) a method of further coating the second coating liquid on the coating layer, (2) spraying or the like. And (3) a method in which the support having the coating layer formed thereon is dipped in the second coating liquid.

In the above method (1), the coating method for applying the second coating liquid is, 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 coater. A known coating method such as 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 coating layer.

The coating amount of the second coating liquid applied on the color material receiving layer is generally 5 to 50 g / m ² ,
30 g / m ² is preferred.

After applying the second coating liquid, generally 40 to 18
It is heated at 0 ° C. for 0.5 to 30 minutes to be dried and cured. Above all, it is preferable to heat at 40 to 150 ° C. for 1 to 20 minutes. For example, when using borax or boric acid as the crosslinking agent contained in the first coating liquid,
It is preferable to perform heating at 60 to 100 ° C. for 5 to 20 minutes.

Further, water, an organic solvent, or a mixed solvent thereof can be used as a solvent in each step.
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

After the color material receiving layer is formed on the support, the surface of the color material receiving layer is smoothed by subjecting the color material receiving layer to calendering through a roll nip under heat and pressure 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 0.030 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.

(Support) As the above 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.

As a material which can be used 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 from the viewpoint 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, baryta paper used for silver salt photographic support, etc.,
High gloss paper support such as RC paper; polyester such as polyethylene terephthalate (PET); cellulose ester such as nitrocellulose, cellulose acetate, cellulose acetate butyrate; polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, etc. A high gloss film which is made opaque by containing a white pigment or the like in a plastic film (may be subjected to surface calendering treatment); or contains the above various paper supports, the above transparent supports or white pigments A support having a coating layer of polyolefin containing or not containing a white pigment on the surface of the high-gloss film is used. 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, a corona discharge treatment,
Those that have been subjected to glow discharge treatment, flame treatment, ultraviolet irradiation treatment, etc. may be used privately.

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. As the wood pulp, 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.

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 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, 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 of forming the colorant receiving layer is formed by adding rutile or anatase type titanium oxide into 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 melt-extruded on the surface of a base paper for coating, a so-called patterning treatment is performed to obtain a matt surface or a matte surface which can be obtained with ordinary photographic printing paper. It is also possible to use those having a silk surface.

As described above, by incorporating the surfactant of the present invention into the colorant-receiving layer, an image-receiving layer having no appearance defect can be obtained. Further, this image-receiving layer effectively prevents fading of the formed image due to ozone in the air, and does not impair the coloring and image density of the inkjet image, and the vivid coloring and high-density image at the time of printing are kept for a long time. It can be stably stored and is easy to handle. Moreover, the colorant receiving layer contains the inorganic pigment fine particles and has a porosity of 50 to 50.
With a three-dimensional network structure of 80%, good ink absorption is exhibited and a high-resolution and high-density image can be formed.
It is also possible to secure excellent ink receiving performance such that bleeding with time in a high-temperature and high-humidity environment is suppressed and the formed image also has high light resistance and water resistance.

[0122]

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 mean "parts by mass" and "% by mass".

—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 and add 0.5 parts of epoxidized behenic acid amide, 1.0 part of anionic polyacrylamide, 0.1 part of polyamide polyamine epichlorohydrin, 0.5 part of cationic polyacrylamide, all in an absolutely dry weight 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 above-mentioned base paper, a 4% aqueous solution of polyvinyl alcohol was added to a fluorescent whitening agent (Whit
0.04% of ex BB, manufactured by Sumitomo Chemical Co., Ltd. was added, and the above 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 g / m ² was obtained.

The wire surface (back surface) side of the obtained base paper was subjected to corona discharge treatment, and then coated with high density polyethylene using a melt extruder so as to have a thickness of 19 μm, and a resin layer consisting of a matte surface. Was formed (hereinafter, the resin layer surface is referred to as “back surface”). The resin layer on the back side is further subjected to corona discharge treatment, and thereafter, aluminum oxide (alumina sol 100, manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (Snowtex O, manufactured by Nissan Chemical Industries, Ltd.) are used as antistatic agents. And 1) were dispersed in water at a ratio of 1: 2 (mass ratio), and the dispersion was applied so that the dry weight was 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 brightener 0.01% ( To polyethylene), MFR
(Melt flow rate) 3.8 low-density polyethylene was melt-extruded using a melt extruder to a thickness of 29 μm to form a high-gloss thermoplastic resin layer on the front surface side of the base paper (hereinafter, This high-gloss surface is referred to as the "front surface"), and was used as a support.

[Example 1] -Preparation of coating liquid for colorant receiving layer- (1) Silica fine particles in the following composition, (2) Dispersant,
(3) Ion-exchanged water was mixed and dispersed with a high-speed rotating colloid mill (Clearmix, manufactured by M Technic Co., Ltd.) at a rotation speed of 10,000 rpm for 20 minutes,
The following (6) diethylene glycol monobutyl ether,
(4) Crosslinking agent, (7) Surfactant, and (5) Polyvinyl alcohol 9% aqueous solution were added and further dispersed under the same conditions as above to prepare a coating material for the colorant receiving layer.

[0128] [Composition of coating liquid for colorant receiving layer] (1) Fine particles of inorganic pigment (Rheoroseal QS-30) 30.0 kg       (Average primary particle size 7 nm, manufactured by Tokuyama Corp.) (2) Dispersant (PAS-M-1 (60%), manufactured by Nitto Boseki Co., Ltd.) 2.5 kg (3) Ion-exchanged water 167.5 kg (4) Crosslinking agent (boric acid (5.3%)) 23.0 kg (5) Water-soluble resin (polyvinyl alcohol 7% aqueous solution) 95.18 kg     (PVA124, Kuraray Co., Ltd.) (6) Diethylene glycol monobutyl ether (100%) 1.09 kg (7) Surfactant (Emulgen 109P, (2%)) 18.22 kg       (Manufactured by Kao Corporation)

—Preparation of Inkjet Recording Sheet— After the front surface of the support was subjected to corona discharge treatment, the colorant-receptive layer coating solution obtained above was placed on the front surface of the support with an extrusion die coater. Using 170
Coating was performed with a coating amount of ml / m ² (coating step), and the coating layer was dried at 40 ° C. (air velocity 5 m / sec) until the solid concentration of the coating layer reached 18%. The coating layer showed a constant drying rate during this period. Immediately thereafter, it is immersed in a basic solution having the following composition for 30 seconds to make 20 g / m ² thereof adhere to the coating layer (step of applying the basic solution), and further at 80 ° C. for 1 hour.
It was dried for 0 minutes (drying step). From this, dry film thickness 3
An inkjet recording sheet (1) of the present invention having a 5 μm colorant receiving layer was prepared.

[0130] [Composition of basic solution]   (1) Basic mordant (PAA-10C (10%) aqueous solution) 10.0 kg         (Nittobo Co., Ltd.)   (2) Ion-exchanged water 34.7 kg   (3) Surface pH adjuster (ammonium chloride, (100%)) 0.3 kg   (4) Surfactant (MegaFac F1405 (10%)) 1.0 kg           (Manufactured by Dainippon Ink and Chemicals, Inc.)   (5) Surfactant (Emulgen 109P, (2%)) 1.0 kg               (Manufactured by Kao Corporation)       * The pH of the basic solution of Example 1 was 9.6.

Example 2 In the basic solution of Example 1, (4) the surfactant (Megafuck F1405 (10
%), Manufactured by Dainippon Ink and Chemicals, Inc.) 1.0 kg, except that the surfactant (Megafuck F475 (10%)), 1.0 kg by Dainippon Ink and Chemicals Co., Ltd. was changed to 1.0 kg. An inkjet recording sheet (2) of the present invention was produced in the same manner as in Example 1. The pH of the basic solution of Example 2 was 9.6.

Comparative Example 1 The amount of the surfactant (Emulgen 109P, 2%) used in the basic solution of Example 1 was changed to 2.0 kg without using the surfactant (Megafuck F1405). An inkjet recording sheet (1) for a comparative example was produced in the same manner as in Example 1 except for the above.
The basic solution of Comparative Example 1 had a pH of 9.6.

<Performance Evaluation> The inkjet recording sheets (1) and (2) of the present invention obtained above and the comparative inkjet recording sheet (1) were evaluated as follows. The evaluation results are shown in Table 1 below.

(Surface Condition) The surface condition of the ink jet recording sheet after the drying process was visually inspected.

(Glossiness) The 60 ° glossiness on the surface of the color material receiving layer of the recording sheet before printing was measured by a digital variable angle glossiness meter (UGV-50DP, manufactured by Suga Test Instruments Co., Ltd.).

(Printing density) A solid image of K (black) was printed on an inkjet recording sheet by an inkjet printer (PM-770C, manufactured by Seiko Epson Corp.), and after leaving for 3 hours, the reflection density of the printed surface Was measured with a Macbeth reflection densitometer.

[0137]

[Table 1]

From the results in the above table, when the surfactant of the present invention was used, a good surface condition was exhibited and no repellant failure was observed. On the other hand, in the comparative example in which the surfactant of the present invention was not used, the repellency failure was 3
8 pieces / 100 m ^{2 were} seen. Further, the print density and gloss were comparable to those of the comparative examples when the surfactant of the present invention was used.

[0139]

INDUSTRIAL APPLICABILITY The present invention can provide an ink jet recording sheet in a good surface condition without deteriorating the ink receiving performance such as print density and glossiness.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuichi Wakata             200, Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo             Within Film Co., Ltd. F-term (reference) 2C056 EA05 EA13 FC06                 2H086 BA15 BA31 BA33 BA35 BA41                       BA46

Claims (8)

[Claims] 1. An inkjet recording sheet having a colorant-receiving layer on a support, wherein the colorant-receiving layer contains a telomer-type fluorochemical surfactant. 2. The ink jet recording sheet according to claim 1, wherein the color material receiving layer further contains inorganic pigment fine particles, a water-soluble resin, and a cross-linking agent. 3. The color material-accepting layer is formed by applying a first coating liquid containing inorganic fine particles, a water-soluble resin and a crosslinking agent, and a second coating liquid capable of crosslinking the water-soluble resin. 2. The inkjet recording sheet according to 2. 4. The ink jet recording sheet according to claim 3, wherein the second coating liquid is basic and contains a telomer type fluorochemical surfactant. 5. The second coating liquid is applied during the drying of the coating layer formed by applying the first coating liquid, and before the coating layer shows a decreasing rate of drying. The inkjet recording sheet according to claim 3, which is obtained by crosslinking and curing the coating layer. 6. The ink jet recording sheet according to claim 2, wherein the inorganic pigment fine particles are gas phase silica having an average primary particle diameter of 20 nm or less. 7. The inkjet recording sheet according to claim 2, wherein polyvinyl alcohol and / or modified polyvinyl alcohol is contained as the water-soluble resin, and a boron compound is contained as the crosslinking agent. 8. The basic solution of the second coating liquid has a pH of 8.
The inkjet recording sheet according to any one of claims 4 to 7, which is 0 or more.