JP2003237223A - Ink jet recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an ink jet recording material being excellent in gloss and ink absorbing properties and in ink bleeding and flaw resistance and having a uniform coating surface. <P>SOLUTION: The ink jet recording material is manufactured by a method wherein a coating solution of at least one ink receiving layer (A) containing vapor-phase silica as a main body and a coating solution of at least one surface coating layer containing colloidal silica as the main substance are applied in this sequence on a water-resistant substrate. The coating solution of the ink receiving layer A contains a water-soluble metal compound, while the colloidal silica is cationic and the coating solution of the surface coating layer contains an organic binder. <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 ink jet recording material, and more particularly to an ink jet recording material having good glossiness, surface property and ink absorbability, and excellent in print density, ink bleeding and scratch resistance. It is a thing.

[0002]

2. Description of the Related Art As a recording material used in an ink jet recording system, a porous material made of a pigment such as amorphous silica and a water-soluble binder such as polyvinyl alcohol is provided on a support called ordinary paper or ink jet recording paper. A recording material provided with the ink receiving layer is known.

For example, JP-A-55-51583 and JP-A-5-51583.
No. 6-157, No. 57-107879, No. 57-10.
No. 7880, No. 59-230787, No. 62-160.
No. 277, No. 62-184879, No. 62-1833.
No. 82 and No. 64-11877, there are proposed recording materials obtained by coating a paper support with a silicon-containing pigment such as silica together with an aqueous binder.

Further, Japanese Patent Publication No. 3-56552 and Japanese Patent Laid-Open No. Hei 2
-188287, 10-81064, 10
-119423, 10-175365, 10
-203006, 10-217601, 11
-20300, Doppei 11-20306, Doppei 11-
Japanese Patent No. 344881 and the like disclose recording materials using synthetic silica fine particles by a vapor phase method (hereinafter referred to as vapor phase method silica). Also, JP-A-62-174183
JP-A-2-276670 and JP-A-5-32037.
And Japanese Patent Application Laid-Open No. 6-199034 disclose recording materials using alumina or alumina hydrate.

However, the above-described vapor-phase process silica is ultrafine particles having an average primary particle diameter of several nm to several tens of nm, and is characterized in that high gloss and good ink absorbency can be obtained. However, on the other hand, there are problems that the printed ink bleeds, scratches are likely to occur on the surface of the ink receiving layer due to the ultrafine particles, and scratches are likely to stand out due to the high gloss. Further, when alumina or alumina hydrate is used, the gloss is high and ink bleeding is good, but the ink absorbency is low and there is a problem that the surface is easily scratched.

On the other hand, conventionally, paper has been generally used as a support for the ink jet recording material, and the paper itself has a role as an ink absorbing layer. In recent years, as photo-like recording sheets have been demanded, recording sheets using a paper support have problems such as gloss, texture, water resistance, cockling (wrinkles or waviness) after printing, and are treated with water resistance. Further, a paper support such as a resin-laminated paper (polyolefin resin-coated paper) in which a polyolefin resin such as polyethylene is laminated on both surfaces of the paper, a plastic film or the like has come to be used. However, these water-resistant supports have a problem that, unlike the paper support, the surface on which the ink receiving layer is provided has high smoothness, so that scratches easily occur on the surface of the ink receiving layer due to rubbing. Also,
Since the water-resistant support itself has no ink absorbing ability, it is necessary to increase the ink absorbing capacity of the ink receiving layer, and for that purpose, it is necessary to apply a thick inorganic fine particle layer having a high porosity. In order to increase the porosity, it is necessary to reduce the ratio of the organic binder to the inorganic fine particles, and the decrease in the amount of the organic binder makes the film of the ink receiving layer brittle, and scratches are more likely to occur. This phenomenon becomes remarkable especially when vapor-phase process silica having an average primary particle diameter of 50 nm or less, alumina hydrate, and alumina are used.

As a technique for solving the above-mentioned problem of scratches, for example, it has been proposed to provide a layer containing colloidal silica as an upper layer. For example, JP-A-6-183
131, JP-A-6-183134, and JP-A-7-10.
1142, JP-A-9-183267, JP-A-10-
No. 71762, JP-A-10-166715, JP-A-20
00-33769, JP-A-2000-37944, 2000-108505, 2000-280609.
No. 2001-10212 and 2001-3539
57 publication. However, merely providing the colloidal silica layer on the upper layer cannot sufficiently satisfy gloss, ink absorbency, ink bleeding, and scratch resistance at the same time. In particular, JP 2000-3
Japanese Patent No. 3769 proposes that colloidal silica gel treated with a metal compound is used for the upper layer to improve the adsorption of the dye component of the ink. However, when vapor phase silica is used for the lower ink receiving layer, the ink is The ink bleeding was not sufficiently prevented, and ink bleeding occurred particularly at the interface between the upper layer and the ink receiving layer. When alumina or alumina hydrate was used as a single layer in the lower ink receiving layer, ink bleeding was good, but ink absorption was insufficient.
Japanese Patent Laid-Open No. 2001-353957 proposes a recording sheet having a lower layer containing vapor phase silica and an upper layer containing colloidal silica. However, a cationic mordant is used in a coating solution containing vapor phase silica. It is described that it is preferable to apply a cationic mordant as a separate solution because addition of the above causes coagulation, and there is no description of cissing between the lower layer and the upper layer at the time of application.

Further, as can be seen from the above-mentioned Japanese Patent Laid-Open Publication, as a conventional general manufacturing method, a lower ink receiving layer is applied and dried, and then an upper colloidal silica layer is applied and dried. The coating method was adopted.
It has been confirmed that the constitution of an ink receiving layer having a relatively large film thickness and a colloidal silica layer having a relatively small film thickness is preferable in order to enhance ink absorbency, which is one of the objects of the present invention. In the case of the configuration, the conventional manufacturing method described above,
That is, it was found that sufficient gloss and scratch resistance cannot be obtained by a method of coating a colloidal silica layer on an ink receiving layer which has been previously coated and dried, and then drying. Further, the method of successively coating a relatively thin cationic colloidal silica layer on the ink receiving layer has a problem that it is difficult to obtain a uniform coated surface.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ink jet recording material which is excellent in gloss, ink absorbency, print density, ink bleeding and scratch resistance, and has a uniform coating surface and no coating unevenness. To do.

[0010]

The above objects of the present invention have been achieved mainly by the following.

(1) A coating solution of an ink receiving layer (A) mainly containing at least one layer of vapor grown silica and a surface coating mainly containing at least one layer of colloidal silica on a water resistant support. In an ink jet recording material obtained by applying the coating liquids of the layers in this order, the coating liquid of the ink receiving layer A contains a water-soluble metal compound, the colloidal silica is a cationic colloidal silica, and the coating of the surface coating layer is performed. An ink jet recording material, wherein the liquid contains an organic binder.

(2) A coating solution for the ink receiving layer (B) containing at least one layer of fumed silica as a main component, at least one layer of alumina hydrate, or alumina as the main component on a water-resistant support. A coating liquid for the ink receiving layer (C) containing
An inkjet recording material obtained by applying a coating solution for a surface coating layer containing at least one layer of colloidal silica as a main component in this order, wherein the colloidal silica is a cationic colloidal silica.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The ink jet recording material of the present invention is provided with at least one layer of an ink receiving layer A mainly containing vapor phase silica and a surface coating layer mainly containing cationic colloidal silica on a water resistant support, or An ink receiving layer B mainly containing at least one layer of fumed silica on a water-resistant support, at least one layer ink receiving layer C mainly containing hydrated alumina or alumina, and a cationic colloidal silica A surface coating layer mainly containing is provided in this order. Here, for example, the ink receiving layer mainly containing vapor phase method silica means containing 50% by mass or more of vapor phase method silica with respect to the total solid content constituting the ink receiving layer, and preferably 60%. The content is preferably at least 65% by mass, particularly preferably at least 65% by mass. Alumina hydrate, alumina,
The same applies to the case where the main component is a cationic corridal silica. In the present invention, the total solid content of fumed silica, alumina hydrate, and alumina contained in each ink receiving layer of the inkjet recording material is 10 to 50.
preferably g / m ^2, the range of 15 to 40 g / m ² is more preferable.

The vapor-phase process silica used in the present invention is also called a dry process as opposed to a wet process, and is generally produced by a flame hydrolysis method. Specifically, a method of burning silicon tetrachloride with hydrogen and oxygen is generally known, but instead of silicon tetrachloride, silanes such as methyltrichlorosilane and trichlorosilane may be used alone or in the form of silicon tetrachloride. It can be used as a mixture with. Vapor phase silica is commercially available as Aerosil from Nippon Aerosil Co., Ltd. and QS type from Tokuyama Corp., and can be obtained.

The average primary particle diameter of the vapor phase silica is 5 to 5
0 nm is preferable, and in order to obtain higher gloss,
30 nm, the specific surface area by BET method is 50-40
It is preferable to use the one having 0 m ² / g. B referred to in the present invention
The ET method is one of the methods for measuring the surface area of powder by the vapor phase adsorption method, and the total surface area of a sample of 1 g from the adsorption isotherm,
That is, this is a method of determining the specific surface area. Nitrogen gas is often used as the adsorbed gas, and the most commonly used method is to measure the adsorbed amount from the change in pressure or volume of the adsorbed gas. The most prominent of the isotherms of multimolecular adsorption is the Brunauer, Emmett, and Teller equation, which is BET.
It is called a formula and is widely used to determine the surface area. The surface area is obtained by determining the adsorption amount based on the BET formula and multiplying the area occupied by one adsorbed molecule on the surface.

As the alumina used in the present invention, γ-alumina which is a γ type crystal of aluminum oxide is preferable, and δ group crystal is particularly preferable. With γ-alumina, the primary particles can be reduced to about 10 nm, but normally, secondary particle crystals of several thousands to tens of thousands nm are treated with ultrasonic waves, a high-pressure homogenizer, a facing collision type jet crusher, etc. Those crushed to about 300 nm can be preferably used.

Alumina hydrate used in the present invention is A
It is represented by a constitutive formula of l ₂ O ₃ · nH ₂ O (n = 1 to 3).
When n is 1, it represents an alumina hydrate having a boehmite structure, and when n is more than 1 and less than 3, it is an alumina hydrate having a pseudo-boehmite structure. It can be obtained by a known production method such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, and hydrolysis of aluminate.

The average particle size of the primary particles of alumina hydrate is
5 to 50 nm is preferable, and in order to obtain higher gloss, tabular grains having 5 to 30 nm and an average aspect ratio (ratio of average particle diameter to average thickness) of 2 or more, preferably 3 to 8 are used. Is preferred.

In the present invention, the ink receiving layer preferably contains an organic binder in order to maintain the characteristics as a film. As the organic binder, various water-soluble polymers or polymer latices are preferably used. Examples of the water-soluble polymer include polyvinyl alcohol, polyethylene glycol, starch, dextrin,
Carboxymethyl cellulose, polyvinylpyrrolidone,
Polyacrylic acid ester type or the like and derivatives thereof are used, but a particularly preferable organic binder is completely or partially saponified polyvinyl alcohol or cation-modified polyvinyl alcohol.

Among the polyvinyl alcohols, those partially or completely saponified with a saponification degree of 80% or more are particularly preferable. Polyvinyl alcohol having an average degree of polymerization of 500 to 5000 is preferable. In addition, examples of the cation-modified polyvinyl alcohol include, for example, JP-A 61-1048.
As described in No. 3, it is a polyvinyl alcohol having a primary to tertiary amino group and a quaternary ammonium group in the main chain or side chain of polyvinyl alcohol.

Examples of the polymer latex used as the organic binder include, for example, acrylic latex, alkyl group, aryl group, aralkyl group,
Acrylic esters or methacrylic esters such as hydroxyalkyl groups, acrylonitrile, acrylamide, homopolymers or copolymers of acrylic acid and methacrylic acid, or the above monomers, and styrenesulfonic acid, vinylsulfonic acid, itaconic acid, Maleic acid,
Examples thereof include fumaric acid, maleic anhydride, vinyl isocyanate, allyl isocyanate, vinyl methyl ether, vinyl acetate, styrene, and copolymers with divinylbenzene. As the olefin latex, a polymer composed of a copolymer of a vinyl monomer and a diolefin is preferable, and as the vinyl monomer, styrene, acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate, vinyl acetate, etc. are preferably used.
Examples of diolefins include butadiene, isoprene and chloroprene.

In the ink receiving layer of the present invention, the organic binder is preferably used in the range of 5 to 35% by mass, and more preferably 10 to 30% by mass based on the inorganic fine particles.

In the present invention, in the case where the ink receiving layer A in contact with the surface coating layer mainly composed of cationic colloidal silica mainly contains vapor grown silica, the water-soluble metal compound is also contained therein, Ink absorbency and ink bleeding are good. Aggregation at the interface between the cationic colloidal silica of the surface coating layer and the vapor phase silica of the ink receiving layer A is prevented by the cationic metal ions from the water-soluble metal compound, and as a result, ink is not accumulated at the interface. It is presumed that the absorption property is improved and the ink bleeding is improved in combination with the effect of the cationic metal ion. Preferably, the average primary particle diameter of the cationic colloidal silica of the surface coating layer is equal to or larger than the average primary particle diameter of the vapor phase method silica of the ink receiving layer A so that the ink solvent at the interface between the surface coating layer and the ink receiving layer A is Permeability becomes good. It is presumed that by making the voids between the vapor phase silica smaller, the cationic colloidal silica particles are less likely to fall into the voids and the solvent permeation resistance due to hole filling is reduced. 2 ink-accepting layers mainly composed of vapor-phase method silica
In the case of more than one layer, the ink receiving layer A in contact with the surface coating layer
It is preferable to add a water-soluble metal compound to each layer other than.

In the present invention, when the ink receiving layer C which is in contact with the surface coating layer mainly composed of cationic colloidal silica mainly contains alumina hydrate or alumina, aggregation occurs at the interface between both layers. A small amount and good ink solvent permeability, but an ink receiving layer B mainly composed of vapor grown silica and preferably containing a water-soluble metal compound is provided between the water resistant support and the ink receiving layer C. The ink absorbency and ink bleeding are good. In addition to the low ink absorbency of the ink receiving layer C being improved by the ink receiving layer B, the inclusion of the water-soluble metal compound in the ink receiving layer B causes aggregation at the interface between the ink receiving layers B and C. It is presumed that it will be prevented. Preferably, the average primary particle size L of the cationic colloidal silica of the surface coating layer, the average primary particle size M of the alumina hydrate or alumina of the ink receiving layer C, and the average primary particle size of the vapor phase process silica of the ink receiving layer B are preferable. When the relationship with N is L ≧ M ≧ N, the permeability of the ink solvent at each interface is good, and the ink bleeding at the interface is also improved. It is presumed that it is due to the effect of preventing the particles of the upper layer from falling into the lower layer by making the size of the voids equal to or smaller than the surface coating layer, the ink receiving layer C, and the ink receiving layer B in this order.

The water-soluble metal compound used in the ink receiving layer in the present invention is preferably a water-soluble polyvalent metal compound. Examples of the polyvalent metal include calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, titanium, chromium, magnesium, tungsten and molybdenum, and they can be used as water-soluble salts of these metals. it can. Specifically, for example,
Calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, cupric chloride, ammonium chloride copper (II) dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel ammonium sulfate hexahydrate, Nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate, ferrous bromide, ferrous chloride, ferric chloride Iron, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, Zinc enolsulfonate, zirconium acetate, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium carbonate, zirconium carbonate, zirconium carbonate, zirconium sulfate, zirconium fluoride, zirconium chloride, zirconium chloride octahydrate, zirconium oxychloride. , Hydroxyzirconium chloride, titanium chloride, titanium sulfate, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate, sodium citrate tungsten, 12 tungstophosphate n Hydrate, 12 tungstosilicic acid 2
Hexahydrate, molybdenum chloride, n-molybdophosphoric acid n-hydrate and the like can be mentioned. Among these, water-soluble salts of aluminum or Group IVa elements (zirconium, titanium) of the periodic table are particularly preferable. In the present invention, the term “water-soluble” means that it is dissolved in water at 1% by mass or more under normal temperature and pressure.

As the water-soluble aluminum compound other than the above, a basic polyaluminum hydroxide compound is preferably used. The main components of this compound are represented by the following general formulas 1, 2
Or 3 and, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [A
l ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ ] ⁵⁺ , [Al
It is a water-soluble polyaluminum hydroxide which stably contains basic and polymeric polynuclear condensed ions such as ₂₁ (OH) ₆₀ ] ³⁺ .

[Al ₂ (OH) _n Cl _6-n ] _m ··· Formula 1 [Al (OH) ₃ ] _n AlCl ₃ · · Formula 2 Al _n (OH) _m Cl _(3n-m) 0 <m < 3n ... Equation 3

These are water treatment agents under the name of polyaluminum chloride (PAC) from Taki Chemical Co., Ltd., under the name of polyaluminum hydroxide (Paho) from Asada Chemical Co., Ltd. It is commercially available from Riken Green under the name Purachem WT and from other manufacturers for the same purpose, and various grades are easily available. In the present invention, these commercial products can be used as they are. These basic polyaluminum hydroxide compounds are also described in Japanese Patent Publication No. 3-24907 and No. 3-42591.

In the present invention, the content of the above-mentioned water-soluble polyvalent metal compound in the ink receiving layer is 0.1 g / m ² to.
10 g / m ^2, and preferably from ^{0.2g / m 2 ~5g / m 2} .

As the cationic polymer used in the present invention for dispersion of vapor-phase method silica, a quaternary ammonium group,
Examples thereof include water-soluble cationic polymers having a phosphonium group or an acid addition product of a primary to tertiary amine. For example, polyethyleneimine, polydialkyldiallylamine, polyallylamine, alkylamine epichlorohydrin polycondensate, JP-A-59-20696 and JP-A-59-3.
No. 3176, No. 59-33177, No. 59-1550
No. 88, No. 60-11389, No. 60-49990.
No. 60-83882, No. 60-109894,
62-198493, 63-49478, 6
3-115780, 63-280681, JP-A-1-40371, 6-234268, 7-12.
Cationic polymers described in Japanese Patent No. 5411, No. 10-193776 and the like can be mentioned. The weight average molecular weight of the cationic polymer used in the present invention is preferably 100,000 or less, more preferably 50,000 or less, and the lower limit is about 2,000.

The amount of these cationic polymers used is preferably in the range of 1 to 8% by mass with respect to the inorganic fine particles.

In the present invention, the ink receiving layer may contain various oil droplets in order to improve the brittleness of the film. Such oil droplets include hydrophobic high-boiling point organic solvents having a solubility in water of 0.01% by mass or less at room temperature (for example, liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, etc.) and polymer particles ( For example, particles obtained by polymerizing one or more polymerizable monomers such as styrene, butyl acrylate, divinylbenzene, butyl methacrylate, hydroxyethyl methacrylate) can be contained. Such oil droplets can be preferably used in the range of 10 to 50% by mass with respect to the hydrophilic binder.

In the present invention, the ink receiving layer preferably contains a hardener together with an organic binder. Specific examples of the hardening agent include formaldehyde, an aldehyde compound such as glutaraldehyde, diacetyl,
Ketone compounds such as chlorpentanedione, bis (2-
Chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5triazine, U.S. Pat. No. 3,288,7
No. 75, a compound having a reactive halogen, such as divinyl sulfone, a compound having a reactive olefin, such as those described in US Pat. No. 3,635,718, and an N-- compound such as described in US Pat. No. 2,732,316. Methylol compounds, isocyanates such as those described in US Pat. No. 3,103,437, US Pat. Nos. 3,017,280 and 2,
983,611, aziridine compounds, US Pat. No. 3,100,704, carbodiimide compounds, US Pat. No. 3,091,537, epoxy compounds, and mucochloric acid, halogen carboxaldehydes. And dioxane derivatives such as dihydroxydioxane, inorganic hardeners such as chromium alum, zirconium sulfate, boric acid and borates.
They may be used alone or in combination of two or more. Among these, boric acid or borate is particularly preferable. The amount of the hardener added is preferably 0.1 to 40% by mass, and more preferably 0.5 to 30% by mass, with respect to the hydrophilic binder constituting the ink receiving layer.

The ink receiving layer further includes a coloring dye, a coloring pigment, a fixing agent for the ink dye, an ultraviolet absorber, an antioxidant,
Various known additives such as a pigment dispersant, a defoaming agent, a leveling agent, a preservative, a fluorescent whitening agent, a viscosity stabilizer, and a pH adjusting agent may be added. The pH of the coating liquid for the ink receiving layer of the present invention is preferably in the range of 3.0 to 6.0,
Especially, the range of 3.5 to 5.5 is preferable. The pH range of the coating liquid for the ink receiving layer and p of the coating liquid for the upper surface coating layer
By combining with H3.0 to 6.0, further ink absorptivity, glossiness, and uniform coating surface can be obtained.

The ink jet recording material of the present invention has at least one surface coating layer mainly containing a cationic colloidal silica on the above-mentioned ink receiving layer.
The shape of colloidal silica is generally spherical or nearly spherical, or a shape in which primary particles of silica are two-dimensionally linked and extended to form a secondary aggregate that is three-dimensionally bonded. It is different from silica gel which is a particle.

The cationic colloidal silica used in the present invention is a colloidal silica whose surface has a positive charge in the coating solution for any surface coating layer having a pH of at least 3.0 to 6.0. For example, it can be obtained by reacting colloidal silica obtained by heat aging silica sol obtained through metathesis of sodium silicate with an acid or through an ion exchange resin layer with a polyvalent metal ion such as aluminum ion, magnesium ion, calcium ion, zirconium ion. The Japanese Patent Publication No. 47-26959.
The publication discloses a cationic colloidal silica treated with aluminum. Examples of commercially available cationic colloidal silica include Snowtex ST-AK-L, ST-UP-AK and S from Nissan Chemical Industries, Ltd.
T-AK, ST-PS-M-AK, ST-AK-YL and the like are commercially available. You may mix and use 2 or more types of cationic corridal silica.

The average primary particle size of the cationic colloidal silica used in the present invention is 10 nm or more, and the range from 30 nm to 100 nm is preferable from the viewpoint of ink absorbency and gloss. 2 with different average primary particle size
You may use together more than 1 type of cationic colloidal silica. In this case, the average primary particle size is 30 nm or more to 60 n
It is preferable to use a combination of less than m and 60 to 100 nm of cationic colloidal silica in combination, and it is more preferable to use 60% by mass or more of cationic colloidal silica having an average primary particle diameter of 30 to 60 nm. When spherical particles are linked to form a chain, the average particle size is 40 to 200 nm, preferably 40 to 160 nm.
Something is used.

The solid coating amount of the cationic colloidal silica in the surface coating layer is generally 0.1 to 8.0 g.
/ M ^2, the range of 0.3 to 4.0 g / m ² is preferred.
As a result, glossiness,
Further improvement of ink fixability and scratch resistance is achieved.

The surface coating layer preferably further contains an organic binder. The organic binder is preferably used in a solid content of 10% by mass or less with respect to the cationic colloidal silica, and the lower limit is about 0.5% by mass. More preferably, the organic binder is used in the range of 1 to 7% by mass. By including the organic binder in this range, the smoothness and scratch resistance are improved without lowering the ink absorbency. Even if the coating solution for the surface coating layer containing an organic binder is applied after the coating solution for the ink receiving layer is applied and dried, the cissing prevention effect can be obtained. In the case of multi-layer coating, it is desirable to add an organic binder to the surface coating layer to improve coatability and obtain a uniform surface without cissing. The water-soluble polymer is preferably used as the organic binder, and the solid content of the cationic colloidal silica is 1 to 7% by mass, more preferably 3 to 7% by mass.

Examples of the organic binder include the above-mentioned organic binders used in the ink receiving layer. Among these, particularly preferred organic binders are completely or partially saponified polyvinyl alcohol or cation-modified polyvinyl alcohol. Especially preferred among the polyvinyl alcohols is a saponification degree of 80%.
The above is a partially or completely saponified product. Polyvinyl alcohol having an average degree of polymerization of 500 to 5000 is preferable.

A hardener may be used in the surface coating layer together with an organic binder. Examples of the hardener include the hardeners used in the ink receiving layer described above. Among these hardeners, boric acid or borate is preferably used. In the surface coating layer, other than the above, a surfactant, a coloring dye, a coloring pigment, an ultraviolet absorber, an antioxidant, a pigment dispersant, a defoaming agent, a leveling agent, a preservative, an optical brightener, a viscosity stabilizer, A pH adjusting agent or the like can be contained.

The ink jet recording material of the present invention comprises a coating liquid for an ink receiving layer containing at least one layer of vapor phase silica, alumina hydrate or alumina as a main component on a water resistant support, and a cationic colloidal silica. The coating solution for the surface coating layer mainly containing is applied in this order, and the coating solution for the surface coating layer has a pH of 3.0 to
The range of 6.0 is preferable from the viewpoint of ink absorbency and print density, and the more preferable range of pH is 3.2.
It is 5.5, and more preferably 3.2 to 4.4. Within the above range, the stability of the cationic colloidal silica in the coating liquid is improved, the pH of the film surface of the recording material to be obtained can be effectively suppressed to prevent ink bleeding, and ink absorption and print density can be improved. It is what

In the present invention, the ink receiving layer and the surface coating layer are coated by a sequential coating method (for example, blade coater, air knife coater,
Roll coater, bar coater, gravure coater, reverse coater, etc.), or a multilayer simultaneous multilayer coating method (for example, a slide bead coater or a slide curtain coater), the effect of the present invention can be obtained, A multilayer simultaneous multilayer coating method is preferably used.

Conventionally, the ink receiving layer and the surface coating layer were generally applied sequentially (a method of applying and drying the ink receiving layer and then applying and drying the surface coating layer). When the coating amount of the cationic colloidal silica in the layer is 8 g / m ² or less in terms of solid content, and further when it is 4 g / m ² or less, the effect of glossiness and scratch resistance of the surface coating layer is sufficient. It turns out that it won't work. This is coated and dried vapor phase silica, alumina hydrate. Or, when a relatively thin surface coating layer is applied on the ink receiving layer mainly containing alumina, the coating solution for the surface coating layer partially penetrates into the voids in the ink receiving layer, and a uniform cationic property is obtained. It is considered that the colloidal silica layer cannot be obtained. In addition, the air present in the voids in the ink receiving layer diffuses into the coating liquid of the upper surface coating layer to form bubbles, which may cause crater-like coating defects (crater-like cissing). It was a hindrance to the gloss and uniformity.

Furthermore, in the case where vapor phase silica, alumina, or alumina hydrate having an average primary particle diameter of 50 nm or less is used in the ink receiving layer, particularly when vapor phase silica is used, the ink receiving layer is formed. When the surface coating layer is applied after being applied and dried once, minute cracks may be generated in the ink receiving layer in the process in which the ink receiving layer is in a wet state again and is dried.

The above-mentioned problems in the case where the relatively thin surface coating layer is successively coated after the coating and drying of the ink receiving layer are solved by simultaneous multilayer coating of the ink receiving layer and the surface coating layer. In the present invention, thin layer coating of the surface coating layer is preferable from the viewpoint of ink absorbency. Cationic colloidal silica is inferior in ink absorbability to vapor-phase process silica, which is preferably used in the ink receiving layer of the present invention, and alumina and alumina hydrate. Therefore, when a colloidal silica layer is provided as an upper layer, a thin layer is preferable. Is preferred. On the other hand, cationic colloidal silica has excellent gloss and scratch resistance,
If a uniform coated surface can be formed, sufficiently high gloss and scratch resistance can be obtained even with a thin layer. Therefore, in order to simultaneously satisfy high levels of ink absorbency, gloss, and scratch resistance, a thin cationic colloidal silica layer should be applied simultaneously with an ink receiving layer mainly composed of vapor phase silica or alumina hydrate. Can be said to be extremely preferable.

In the multi-layer simultaneous multi-layer coating, a plurality of coating liquids for the ink receiving layer and the surface coating layer are coated in a laminated state on the support using a coater such as a slide bead coater or a slide curtain coater. Prevents agglomeration at the interface between the two layers and prevents coating unevenness when the coating liquid for the ink receiving layer and the surface coating layer is laminated or when the coating liquid for the surface coating layer is applied to the dried ink receiving layer How to do
The surface coating layer is mainly composed of cationic colloidal silica, preferably an organic binder is used, and when the ink receiving layer immediately below is mainly composed of vapor phase method silica, a water-soluble metal compound is contained, or an alumina hydrate or an alumina is used. Mainly,
The pH of the coating solution for the surface coating layer is preferably 3.0 to 6.
0, more preferably adjusted to a range of 3.2 to 5.5, and even more preferably the pH of the coating liquid for the ink receiving layer is 3.0 to 3.0.
It is solved by setting it to 6.0.

The preferred constitution of the surface coating layer is as described above, but the concentration of the cationic colloidal silica in the coating liquid for the layer is preferably about 3 to 25% by mass, more preferably 5 to 20% by mass. Is. The wet coating amount of the coating liquid for the surface coating layer is preferably about 7 to 50 g / m ² ,
-30 g / m ² is more preferable.

The constitution of the ink receiving layer is also as described above, but the solid content concentration of vapor phase silica, alumina hydrate and alumina in the coating liquid of the ink receiving layer is preferably about 5 to 20% by mass. . The ink receiving layer is
Even in the case of a plurality of layers, it is preferable that all layers have a concentration within the above range. The moisture application amount of the ink receiving layer coating solution is
In the case of a single layer or multiple layers, a total of 100 to 3
About 100 g / m ² is suitable. The pH of the coating liquid for the ink receiving layer is preferably in the range of 3.0 to 6.0, and particularly 3.5.
The range of -5.5 is preferable. By adjusting the pH within this range, aggregation at the interface with the upper surface coating layer is further suppressed, and the ink absorbency of the obtained recording material is improved.

Examples of the water resistant support used in the present invention include polyester resins such as polyethylene terephthalate, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride, polyimide resins, cellophane and celluloid plastic resins. Film, and paper and resin film bonded together,
A polyolefin resin-coated paper in which a hydrophobic resin such as a polyolefin resin is laminated on at least one surface of the paper is preferable. The thickness of these water resistant supports is 50 to 300 μm.
m, preferably 80 to 260 μm.

The polyolefin resin-coated paper support preferably used in the present invention (hereinafter referred to as polyolefin resin-coated paper) will be described in detail. The water content of the polyolefin resin-coated paper used in the present invention is not particularly limited, but is preferably in the range of 5.0 to 9.0%, more preferably 6.0 to 9.0% in terms of curling property. It is a range. The water content of the polyolefin resin-coated paper can be measured using an arbitrary water content measuring method. For example, an infrared moisture meter, an absolute dry weight method, a dielectric constant method, a Karl Fischer method or the like can be used.

The base paper constituting the polyolefin resin-coated paper is not particularly limited, and commonly used paper can be used, but more preferably, for example, a smooth base paper used for a photographic support is preferred. . As the pulp constituting the base paper, one kind or a mixture of two or more kinds of natural pulp, recycled pulp, synthetic pulp and the like is used. This base paper has a sizing agent, a paper strengthening agent, which are generally used in papermaking,
Additives such as fillers, antistatic agents, optical brighteners and dyes are blended.

Further, a surface sizing agent, a surface paper strength agent, a fluorescent whitening agent, an antistatic agent, a dye, an anchoring agent or the like may be applied on the surface.

The thickness of the base paper is not particularly limited, but it is preferable that the paper has good surface smoothness, such as being compressed by applying pressure with a calender during or after the paper making, and its basis weight is 30 to 250 g / m ² is preferable.

As the polyolefin resin for coating the base paper, homopolymers of olefins such as low density polyethylene, high density polyethylene, polypropylene, polybutene and polypentene or copolymers of two or more olefins such as ethylene-propylene copolymers are used. As a coalesced product and a mixture thereof, those having various densities and melt viscosity indexes (melt indexes) can be used alone or by mixing them.

In the resin of the polyolefin resin-coated paper, white pigments such as titanium oxide, zinc oxide, talc and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, zinc stearate, calcium stearate and stearin. Fatty acid metal salts such as aluminum acid salt and magnesium stearate, antioxidants such as Irganox 1010 and Irganox 1076,
Various additives such as cobalt blue, ultramarine blue, cesian blue, phthalocyanine blue and other blue pigments and dyes, cobalt violet, fast violet, magenta pigments and dyes such as manganese purple, optical brighteners and ultraviolet absorbers It is preferable to add them in combination.

The polyolefin resin-coated paper is mainly produced by a so-called extrusion coating method in which a polyolefin resin is cast on a running base paper in a molten state by heating, and at least one surface thereof is coated with the resin. Further, it is preferable that the base paper is subjected to an activation treatment such as a corona discharge treatment or a flame treatment before the resin is coated on the base paper. From the viewpoint of ink absorbency, it is preferable not to cover the surface of the base paper on which the ink receiving layer is provided (front surface of the base paper) with the resin, and to prevent curling on the opposite surface (back side of the base paper). preferable. The back surface is usually a matte surface, and the back surface or both the front and back surfaces can be subjected to activation treatment such as corona discharge treatment and flame treatment as required. The thickness of the resin coating layer is not particularly limited, but is generally 5 to 50 μm on one side and resin is coated on one side or both sides. When only one surface is coated with a resin, the thickness of the polyolefin resin coating layer is preferably about 5 to 30 μm from the viewpoint of curl of the obtained ink jet recording material.

The surface of the polyolefin resin-coated paper of the present invention on which the ink receiving layer is applied (hereinafter referred to as the surface of the polyolefin resin-coated paper) may be the base paper surface, but from the viewpoint of gloss and smoothness, the polyolefin is used. It is manufactured by heating and melting a resin with an extruder, extruding it into a film form between a base paper and a cooling roll, press-bonding and cooling. At this time, the cooling roll is used to form the surface shape of the polyolefin resin coating layer, and the surface of the resin layer is shaped into a mirror surface, a finely rough surface, or a patterned silk-like or matte shape depending on the shape of the cooling roll surface. It can be processed. From the viewpoint of preventing cracks in the ink receiving layer and the surface coating layer, it is preferable to perform a patterning process so that Ra defined by JIS-B-0601 on the surface of the resin coating layer is 0.8 to 5 μm.

The surface of the polyolefin resin-coated paper of the present invention on which the ink receiving layer is coated (hereinafter referred to as the back surface of the polyolefin resin-coated paper) may be the base paper surface when the surface is resin-coated. In order to improve the curl property and the printed image, a polyolefin resin is mainly heated and melted by an extruder, extruded in a film form between a base paper and a cooling roll, and pressure-bonded and cooled to produce the film. At this time, the cooling roll is JIS-B based on the transportability of the printer and the printed image.
It is preferable to perform a patterning process on the surface of the cooling roll so that Ra defined by −0601 is 0.8 to 5 μm, which is slightly roughened according to the shape of the surface of the cooling roll, or patterned, for example, silk or mat.

The method for providing the polyolefin resin coating layer on the back surface or the surface of the base paper is as follows: extruding the heat-melting resin to apply the electron beam curing resin, and then irradiating with an electron beam, or a polyolefin resin emulsion. There is a method of applying the coating liquid of (1) and drying it to perform surface smoothing treatment. In either case, a polyolefin resin-coated paper applicable to the present invention can be obtained by imprinting with a heat roll having irregularities.

An undercoat layer may be provided on the surface of the polyolefin resin-coated paper used in the present invention. The undercoat layer is applied and dried on the surface of the water-resistant support in advance before the ink receiving layer is applied. This undercoat layer is
It mainly contains a water-soluble polymer or polymer latex capable of forming a film. Water-soluble polymers such as gelatin, polyvinyl alcohol, polyvinylpyrrolidone and water-soluble cellulose are preferable, and gelatin is particularly preferable. The adhesion amount of these water-soluble polymers is 10 to 50.
Preferably ^{0mg / m 2, 20~300mg / m} 2 is more preferable. Furthermore, it is preferable that the undercoat layer further contains a surfactant or a hardener. Further, it is preferable to perform corona discharge before applying the undercoat layer to the resin-coated paper.

[0062]

The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples. Parts in the examples represent parts by mass.

Example 1 <Preparation of polyolefin resin-coated paper> Hardwood bleached kraft pulp (LBKP) and hardwood bleached sulfite pulp (L
A 1: 1 mixture of BSP) was beaten to 300 ml with Canadian Standard Freeness to prepare a pulp slurry. Alkyl ketene dimer as a sizing agent to 0.5% by weight of pulp, polyacrylamide as a strength agent to 1.0% by weight of pulp, cationized starch to 2.0% by weight of pulp, and polyamide epichlorohydrin resin. 0.5% by mass of pulp was added and diluted with water to obtain a 1% slurry. This slurry was made into a paper by a Fourdrinier paper machine so as to have a basis weight of 170 g / m ² , dried and conditioned to obtain a base paper for a polyolefin resin-coated paper. A polyethylene resin composition in which 10% by mass of anatase-type titanium was uniformly dispersed in 100% by mass of a low-density polyethylene resin having a density of 0.918 g / cm ³ was melted at 320 ° C. in a paper-making base paper, and 200 m / Min to give a thickness of 35 μm, and extrusion coating was carried out using a cooling roller having a micro-roughened surface. Density 0.962g / cm on the other side
70 parts by mass of high density polyethylene resin ³ and density 0.91
Similarly, 30 parts by mass of the low-density polyethylene resin of Example 8 was melted at 320 ° C., extrusion-coated to a thickness of 30 μm, and extrusion-coated using a roughened cooling roll.

A high-frequency corona discharge treatment was applied to the surface of the above polyolefin resin-coated paper, and then a subbing layer having the following composition was coated and dried so that gelatin was 50 mg / m ² to prepare a water-resistant support.

[0065] <Undercoat layer> 100 parts of lime-processed gelatin Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chrome Alum 10 copies

On the surface of the obtained water-resistant support on which the subbing layer was provided, the ink receiving layer coating liquid 1 and the surface coating layer coating liquid 1 having the following compositions were simultaneously multilayer coated with a slide bead coater. The concentration of vapor-phase method silica in the ink receiving layer coating liquid 1 was adjusted to 9% by mass. The wet coating amount of the coating liquid for the ink receiving layer is 220 g / m ² (the solid coating amount of vapor phase method silica is 20 g / m ² ). The concentration of the cationic colloidal silica in the coating liquid 1 for the surface coating layer was adjusted to 8% by mass. The amount of moisture of the surface coating layer coating liquid 1 is 1
It is 2.5 g / m ² (the solid coating amount of the cationic colloidal silica is 1 g / m ² ).

<Ink Receptor Layer Coating Liquid 1> 100 parts of vapor phase silica (average primary particle size 7 nm, specific surface area by BET method 300 m ² / g) dimethyl diallyl ammonium chloride homopolymer 4 parts (Daiichi Kogyo Seiyaku Co., Ltd.) Made by Charol DC902P, molecular weight 9000) boric acid 3 parts polyvinyl alcohol 22 parts (saponification degree 88%, average degree of polymerization 3500) basic polyaluminum hydroxide 3 parts (trade name: Purachem WT, manufactured by Riken Green Co., Ltd.) Interface Activator 0.3 part (betaine type; manufactured by Nippon Surfactant Co., Ltd., Swanol AM) The pH of the coating solution was adjusted to 4.0.

[0068] <Surface coating layer coating liquid 1> 100 parts of cationic colloidal silica   (Snowtex ST-AK-L manufactured by Nissan Chemical Industries, Ltd., average primary particle size 45 nm) Polyvinyl alcohol 4 parts   (Saponification degree 88%, average degree of polymerization 3500) Surfactant 0.1 part (Nonionic type; Nikol BT-9 manufactured by Nippon Surfactant Co., Ltd.)

The surface coating layer coating solution 1 was prepared as follows. First, water is added so that the concentration of the cationic colloidal silica is 12% by mass to prepare an aqueous solution,
While stirring this cationic colloidal silica aqueous solution at high speed with a high-speed rotating disperser, polyvinyl alcohol and a surfactant were sequentially added to prepare a coating solution. P of this coating liquid
H was 4.3.

<Surface coating layer coating liquid 2> The above-mentioned surface coating layer coating liquid 1 was prepared. However, while stirring the cationic colloidal silica aqueous solution at high speed with a high-speed rotating disperser, 0.5% by mass of sodium hydroxide was gradually added, and
After increasing H, polyvinyl alcohol and a surfactant were sequentially added while stirring to prepare a coating solution. The pH of this coating solution was 5.0.

<Surface coating layer coating liquid 3> The same coating liquid as the surface coating layer coating liquid 2 was prepared. However, the amount of sodium hydroxide was adjusted to adjust the pH of the coating solution to 6.0.

<Surface coating layer coating liquid 4> A coating liquid was prepared in the same manner as the surface coating layer coating liquid 1. However, 1% by mass nitric acid was gradually added to the cationic colloidal silica aqueous solution with high-speed rotation disperser to reduce the pH, and then polyvinyl alcohol and a surfactant were sequentially added with stirring to prepare a coating solution. did. The pH of this coating solution is 3.
It was 6.

<Surface coating layer coating liquid 5> The same coating liquid as the surface coating layer coating liquid 4 was prepared. However, the amount of nitric acid was adjusted to adjust the pH of the coating liquid to 3.1.

<Surface coating layer coating liquid 6> A coating liquid was prepared in the same manner except that the polyvinyl alcohol was removed from the surface coating layer coating liquid 1.

The above ink receiving layer and the surface coating layer layers 1 to
Inkjet recording materials A1 to A6 were produced by simultaneously coating 6 of each of the layers. However, in A6, the ink receiving layer coating liquid and the surface coating layer coating liquid caused cissing, and satisfactory surface properties were not obtained. Therefore, the glossiness, the ink absorbency, and the print density of the five types of recording materials A1 to A5 were obtained. , Ink bleeding, and scratch resistance were evaluated by the following methods.
Furthermore, the degree of occurrence of unevenness on the coated surface was also evaluated. The results are shown in Table 1.

<Glossiness> The glossiness of the recording material before printing was observed by oblique light and evaluated according to the following criteria. ◯: Has a high glossiness comparable to that of a color photograph. Δ: There is a glossy feeling similar to that of art and coated paper. X: There is no glossiness comparable to art and coated paper.

<Ink absorbency> Black solid printing was carried out with an ink jet printer PM-880C manufactured by Seiko Epson Corporation, the ink absorption state and the occurrence of mottling (image density unevenness) were visually observed, and evaluated according to the following criteria. did. A: Ink is absorbed promptly and no mottling occurs. ○: Ink absorption is slightly slow, but no mottling occurs. Δ: Ink slightly overflows on the printed surface, and slight occurrence of mottling is recognized. X: Ink overflows on the printed surface, and strong mottling is clearly observed.

<Print density> Black 1 with an inkjet printer (PM-880C, manufactured by Seiko Epson Corporation)
The area printed with 00% was left at 23 ° C. and 55% RH for one day, and the reflection density was measured by a Macbeth densitometer.

<Ink bleeding> A sheet with 100% black fine lines printed by an ink jet printer (PM-880C manufactured by Seiko Epson Corporation) was stored for 3 days in an atmosphere of 35 ° C and 80% RH, and the degree of bleeding was visually observed. It was judged by. ○: No bleeding at all. Δ: There is some blurring, but no problem. X: Large bleeding.

<Scratch resistance> Two recording materials which are not printed are superposed on the surface, 100 g of weight is placed on the recording material, and the recording material below is extracted, and scratches on the surface of the ink receiving layer are visually observed. I observed. ◯: No scratch is recognized. Δ: Some scratches are recognized. X: A scratch is clearly recognized.

<Unevenness of Coating Surface> The occurrence of unevenness in the coating surface was visually observed and evaluated according to the following criteria. ◯: No unevenness is observed on the coated surface. Δ: Slight unevenness is recognized on the coated surface. X: Unevenness is clearly recognized on the coated surface.

[0082]

[Table 1] ───────────────────────────────────   Recording material Gloss ink Ink print density Ink scratch resistance Coating unevenness Remarks                     Absorption ───────────────────────────────────     A1 ○ ◎ 2.30 ○ ○ ○ The present invention     A2 ○ ◎ 2.22 ○ ○ ○ The present invention     A3 ○ ○ 2.11 △ ○ △ The present invention     A4 ○ ◎ 2.34 ○ ○ ○ The present invention     A5 ○ ○ 2.32 ○ △ ○ The present invention ───────────────────────────────────

Example 2 On the same water-resistant support as in Example 1, the following three ink receiving layer coating solutions 2 and 3 and the surface coating layer coating solution 1 of Example 1 were slid. Simultaneous multilayer coating with a bead coater. The amount of moisture applied is the ink receiving layer coating liquid 2
180 g / m ² (the solid coating amount of the vapor phase silica is 16.
2 g / m ² ), ink receiving layer coating liquid 3 is 40 g / m ² (alumina hydrate solid content coating amount is 6 g / m ² ), and surface coating layer coating liquid 2 is 12.5 g / m ² (cation The coating amount of solid colloidal silica is 1 g / m ² ).

<Ink Receptor Layer Coating Liquid 2> 100 parts of vapor phase silica (average primary particle size: 12 nm, specific surface area by BET method: 200 m ² / g) Dimethyldiallylammonium chloride homopolymer 4 parts (Daiichi Kogyo Seiyaku Co., Ltd.) Manufactured by Charol DC902P, molecular weight 9000) boric acid 3 parts polyvinyl alcohol 20 parts (saponification degree 88%, average degree of polymerization 3500) basic polyaluminum hydroxide 3 parts (trade name: Purachem WT, manufactured by Riken Green Co., Ltd.) Interface Activator 0.3 part (betaine type; manufactured by Nippon Surfactant Co., Ltd., Swanol AM) The pH of the coating solution was adjusted to 4.0. The solid content concentration of the vapor-phase method silica in the coating liquid is 9% by mass.

<Ink-Receptive Layer Coating Liquid 3> Alumina hydrate 100 parts (pseudo-boehmite, average primary particle size 13 nm, flat plate having aspect ratio 3) Nitric acid 1 part Boric acid 0.5 part Polyvinyl alcohol 10 parts (saponification degree) 88%, average degree of polymerization 3500) Surfactant 0.3 part (betaine type; manufactured by Nippon Surfactant Co., Ltd., Swanol AM) The pH of the coating solution was adjusted to 4.2. The solid content concentration of the alumina hydrate in the coating liquid is 15% by mass.

Ink jet recording materials B1 to B5 were prepared by simultaneously coating the ink receiving layers 2 and 3 and the surface coating layers 1 to 5 of Example 1 in a multilayered manner. The five types of recording materials were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0087]

[Table 2] ───────────────────────────────────   Recording material Gloss ink Ink print density Ink scratch resistance Coating unevenness Remarks                     Absorption ───────────────────────────────────     B1 ○ ◎ 2.41 ○ ○ ○ The present invention     B2 ○ ◎ 2.34 ○ ○ ○ The present invention     B3 ○ ○ 2.21 △ ○ △ The present invention     B4 ○ ◎ 2.45 ○ ○ ○ The present invention     B5 ○ ○ 2.42 ○ △ ○ The present invention ───────────────────────────────────

Example 3 Recording materials C1 to C5 were prepared according to the recording material A4 of Example 1. However, the surface coating layer coating liquid 4 was changed as follows.

<Production of Recording Material C1> The cationic colloidal silica of the coating liquid 4 for the surface coating layer used in the recording material A4 of Example 1 was added to Snowtex P having an average particle diameter of 135 nm.
A recording material C1 was prepared in the same manner as in Example 1 except that the surface coating layer coating liquid 6 was used instead of S-M-AK (manufactured by Nissan Chemical Industries, Ltd., chain cationic colloidal silica).

<Preparation of Recording Material C2> The cationic colloidal silica of the coating solution 4 for the surface coating layer used in the recording material A4 of Example 1 was mixed with Snowtex ST-AK-YL (Nissan Chemical Co., Ltd.) having an average primary particle diameter of 65 nm. Recording material C was prepared in the same manner as in Example 1 except that the coating solution 7 for surface coating layer was used instead of the spherical cationic colloidal silica manufactured by Kogyo Co., Ltd.
2 was produced.

<Preparation of Recording Material C3> Recording Material C3 was prepared in the same manner as in Recording Material A4 of Example 1 except that 4 parts of polyvinyl alcohol in the surface coating layer coating solution 4 was changed to 1.5 parts. It was made.

<Preparation of Recording Material C4> A recording material C4 was prepared in the same manner as in Example 1 except that the surface coating layer coating solution 4 used in Example 1 contained 4 parts of polyvinyl alcohol. It was made.

<Preparation of Recording Material C5> The cationic colloidal silica of the coating liquid 4 for the surface coating layer used in the recording material A4 of Example 1 was mixed with Snowtex ST-OL40 (Nissan Chemical Industry ( Co., Ltd., spherical anionic colloidal silica) was used instead of the surface coating layer coating liquid 8, and two layers with the ink receiving layer coating liquid 1 were simultaneously layered with a slide bead coater, but aggregated at the interface of the two layers. Occurred, the surface was roughened and the glossiness was significantly reduced. First, apply the ink receiving layer coating liquid 1 with a bar coater.
After drying, the coating solution 8 for surface coating layer of Example 1 was applied using an air knife coater and dried to prepare a recording material C5.

The three types of recording materials C1 to C5 and the recording material A4 of Example 1 were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0095]

[Table 3] ───────────────────────────────────   Recording material Gloss ink Ink print density Ink scratch resistance Coating unevenness Remarks                     Absorption ───────────────────────────────────     A4 ○ ◎ 2.35 ○ ○ ○ The present invention     C1 ○ ◎ 2.23 ○ ○ ○ The present invention     C2 ○ ◎ 2.25 ○ ○ ○ The present invention     C3 ○ ◎ 2.26 ○ ○ ○ The present invention     C4 ○ ◎ 2.18 ○ △ △ The present invention     C5 △ △ 1.96 × △ △ Comparative example ───────────────────────────────────

Example 4 A recording material was prepared according to the recording material A4 of Example 1.
However, by increasing the solid content concentration of the cationic colloidal silica in the surface coating layer coating solution 1 and increasing the moisture coating amount,
The solid coating amount of the cationic colloidal silica was changed as follows. Recording Material D1: Cationic Colloidal Silica Solid Content Application 3 g / m ² Moisture Application 30 g / m ² (Cationic colloidal silica solid content concentration is 10% by mass) Recording material D2: Cationic colloidal silica solid coating amount 6 g / m ² Moisture coating amount 30 g / m ² (Cationic colloidal silica solid content concentration is 20% by mass) Recording material D3: Cationic colloidal silica solid content application amount 10 g / m ² Moisture application amount 40 g / m ² (Cationic colloidal silica solid content concentration is 25% by mass)

The three kinds of recording materials D1 to D3 and the recording material A4 of Example 1 were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0098]

[Table 4] ───────────────────────────────────   Recording material Gloss ink Ink print density Ink scratch resistance Coating unevenness Remarks                     Absorption ───────────────────────────────────     A4 ○ ◎ 2.38 ○ ○ ○ The present invention     D1 ○ ◎ 2.35 ○ ○ ○ The present invention     D2 ○ ○ 2.31 ○ ○ ○ The present invention     D3 ○ △ 2.34 ○ ○ ○ The present invention ───────────────────────────────────

Example 5 In accordance with Examples 1 and 4, recording materials were prepared in which the coating amount of the solid content of the cationic colloidal silica was changed. However, using a bar coater, first, the ink receiving layer coating liquid 1
Is applied and dried, and then the surface coating layer coating solution 6 of Example 1
4, the surface coating layer coating liquids used in the recording materials D1, D2 and D3 of Example 4 were coated and dried using an air knife coater to obtain recording materials E1 to E5 in the order of the description of the surface coating layer coating liquids. It was made. The recording material thus produced was evaluated in the same manner as in Example 1. Also,
The coated surface was visually observed and evaluated according to the following criteria. The evaluation results are shown in Table 5.

<Coating surface> ◯: There is no uneven gloss or crater-like cissing. Δ: Uneven gloss and crater-like cissing are slightly observed. X: Uneven gloss and crater-like cissing are clearly observed.

[0101]

[Table 5] ───────────────────────────────────   Recording material Gloss ink Ink print density Ink scratch resistance Coating surface Remarks                     Absorption ───────────────────────────────────     E1 △ × 1.88 △ × × Comparison     E2 △ ◎ 2.24 ○ △ × The present invention     E3 △ ◎ 2.20 ○ △ △ The present invention     E4 △ ○ 2.18 ○ ○ △ The present invention     E5 ○ △ 2.21 ○ ○ △ The present invention ───────────────────────────────────

[0102]

As is apparent from the above examples, when a surface coating layer mainly composed of cationic colloidal silica is provided on the upper layer of the ink receiving layer mainly containing vapor phase silica, hydrated alumina or alumina. When the ink receiving layer is mainly composed of vapor-phase method silica, it contains a water-soluble metal compound, and the pH of the coating liquid for the surface coating layer is in the range of 3.0 to 6.0, preferably pH 3.2 to 5. The glossiness, ink absorbency, print density, ink bleeding, and scratch resistance of the inkjet recording material produced by adjusting to the range of 5 are improved. Particularly, the recording materials B1 to B5 using pseudoboehmite as the upper layer of the ink receiving layer of Example 2 are the same as those of Example 1
The glossiness was much better than that of the recording materials A1 to A5. Although the recording material C1 using the chain-like cationic colloidal silica having an average particle diameter of 135 nm has a slightly lower print density than the recording material A4 using the cationic colloidal silica having an average primary particle diameter of 45 nm. Other properties were similarly good. The recording density of the recording material C2 using the cationic colloidal silica having an average primary particle diameter of 65 nm was slightly lower than that of the recording material A4, but other characteristics were good. The recording material C3 in which the amount of the organic binder in the surface coating layer was reduced to 1.5 parts showed almost the same good characteristics as the recording material A4, but the recording material C4 in which the amount of the organic binder was 0.5 parts was , Scratch resistance and coating unevenness decreased. The recording material C5 using the anionic colloidal silica having an average primary particle diameter of 45 nm, which is a comparative example, has lower glossiness, ink absorptivity, print density, and coating unevenness, as compared with the recording material A4, and ink bleeding is large. Became worse. The solid coating amount of the cationic colloidal silica in the surface coating layer is in the range of 0.3 to 8.0 g / m ² , and more preferably 0.3 to 4.0 g.
In the range of / m ² , the ink absorbency can be further improved.
Furthermore, simultaneous multi-layer coating of an ink receiving layer mainly containing inorganic fine particles and a cationic colloidal silica layer provides better coating unevenness than sequential coating, and favorable results in terms of glossiness and scratch resistance. can get. This effect is particularly remarkable when the solid coating amount of the cationic colloidal silica is 8 g / m ² or less, and further 2 g / m ² or less.

Claims (15)

[Claims] 1. A coating solution of an ink receiving layer (A) mainly containing at least one layer of fumed silica on a water-resistant support, and a surface coating layer mainly containing at least one layer of colloidal silica. The coating liquid for the ink-receiving layer A contains a water-soluble metal compound, the colloidal silica is cationic colloidal silica, and the coating liquid for the surface coating layer An ink jet recording material containing an organic binder. 2. A coating solution for an ink receiving layer (B) containing at least one layer of fumed silica as a main component, at least one layer of alumina hydrate, or mainly containing alumina on a water-resistant support. In the ink jet recording material, the coating liquid for the ink receiving layer (C) and the coating liquid for the surface coating layer mainly containing at least one layer of colloidal silica are applied in this order, and the colloidal silica is a cationic colloidal silica. An inkjet recording material characterized by being present. 3. The pH of the coating solution for the surface coating layer is 3.0.
The ink-jet recording material according to claim 1 or 2, characterized in that 4. The ink jet recording material according to claim 2, wherein the surface coating layer contains an organic binder. 5. The coating solution for the ink receiving layer B contains a water-soluble metal compound.
6. The inkjet recording material according to any one of 1. 6. The ink jet recording material according to claim 1, wherein the coating liquid for the ink receiving layer A has a pH of 3.0 to 6.0. 7. The ink jet recording material according to claim 2, wherein the coating liquid for the ink receiving layers B and C has a pH of 3.0 to 6.0. 8. The method according to claim 1, wherein the coating liquid for the ink receiving layer A and the coating liquid for the surface coating layer are simultaneously and multilayer coated.
7. The inkjet recording material according to 3 or 6. 9. The ink jet recording material according to claim 2, wherein the coating liquid for the ink receiving layers B and C and the coating liquid for the surface coating layer are simultaneously applied in a multilayer coating. 10. The inkjet recording material according to claim 1, wherein the average primary particle size of the cationic colloidal silica is 30 nm or more. 11. The ink jet recording material according to any one of claims 1 to 10, wherein the surface of the cationic colloidal silica is treated with a polyvalent metal compound. 12. The ink according to claim 1, wherein the vapor phase silica of the ink receiving layer A has an average primary particle size of 30 nm or less. Inkjet recording material. 13. The average primary particle diameter of alumina hydrate or alumina of the ink receiving layer C is 30 nm or less,
The average primary particle diameter of the vapor grown silica of the ink receiving layer B is equal to or larger than the average primary particle diameter thereof.
The inkjet recording material according to any one of 9, 10 and 11. 14. The ink jet recording material according to claim 1, wherein the surface coating layer contains an organic binder in a solid content of 1 to 7 mass% with respect to the cationic colloidal silica. 15. The coating amount of the cationic colloidal silica is 0.3 to 4.0 g / m ² in terms of solid content.
15. The inkjet recording material according to any one of 14 above.