JP2003291490A - Inkjet recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inkjet recording material formed by coating an alumina sol coating liquid, which has high gloss and excellent ink absorbency and prevents bronzing from developing at printing. <P>SOLUTION: In the inkjet recording material providing at least one ink accepting layer including an alumina hydrate and a water soluble binder on a support, the ink accepting layer is formed by coating the alumina sol coating liquid including an alumina hydrate dispersant, which is prepared by deflocculating fine alumina hydrate powder with an inorganic acid under the state that the water is employed as a solvent, the water soluble binder and an amino alcohol-based compound. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording material coated with an alumina sol coating liquid, and more particularly to an ink jet recording material having high gloss and excellent ink absorbency and preventing the occurrence of bronzing during printing.

[0002]

2. Description of the Related Art Ink-jet recording has no noise and is capable of high-speed printing. It is easy to perform multicolor printing by using multiple ink nozzles, and with the recent advances in inkjet recording technology, high quality, storability, and high-quality surfaces approaching silver salt color photographs Quality and luster have come to be required. In ink jet recording materials called photo grades, which require high image quality comparable to silver salt photographs, water-resistant supports such as so-called RC bases and polyester films in which paper is laminated with polyethylene resin are used as supports in terms of gloss and surface quality. Commonly used. In the case of these supports, it is necessary that the ink receiving layer provided on the support absorbs all the ink, and a high level is required for the drying property and the absorbing property of the ink.

As such an ink jet recording material having a high image quality comparable to that of a silver salt photograph, a recording material in which alumina or alumina hydrate fine particles are provided as an ink absorbing layer on a support is known.

For example, JP-A-62-174183, JP-A-2-276670, JP-A-5-32037 and JP-A-6-199034 disclose recording materials using alumina or alumina hydrate. ing.

In these methods, a layer made of porous alumina hydrate is provided to improve ink absorbency and the like, but it is still unsatisfactory for occurrence of a phenomenon such as gloss abnormality such as metallic gloss or so-called bronzing in a printed portion. It is enough. Bronzing is caused by the fact that the coloring material of the ink is not fixed uniformly on the ink receiving layer on the surface of the ink receiving layer and the coloring material is excessively aggregated.

[0006] Japanese Patent Laid-Open No. 2001-253164 contains a dye mordant cross-linked with a cross-linking agent in the porous ink receiving layer, or two or more kinds of cationic polymers in the porous ink receiving layer in 2001-39026. Although technologies for bronzing prevention such as containing are disclosed, they are not at a satisfactory level due to insufficient effects and reduced ink absorbency. Also, Japanese Patent Laid-Open No. 2001-
Japanese Patent No. 341408 discloses a technique for preventing bronzing by impregnating an ink jet recording material having a porous ink absorbing layer with borax to raise the film surface pH. Not at all.

Japanese Patent Laid-Open Nos. 2000-27093 and 2000
No. 239578 discloses a method of drying at a relatively low temperature suitable for applying to an RC base laminated with a polyethylene resin or a polyester film, and a porous layer made of inorganic fine particles such as silica or alumina is formed to absorb ink. A technique for improving the property is disclosed. However, when alumina or alumina hydrate is used as the ink absorbing layer, the coating amount is required to be larger than that of synthetic silica fine particles such as vapor-phase method silica, and the high concentration of the coating liquid and the coating property Improvement is desired.

Alumina sol and alumina sol coating liquid used for ink jet recording materials and coating materials are
JP-A Nos. 7-76161, 8-295509, 8
-333115 gazette etc. are disclosed. However, they are described for an alumina sol obtained by directly synthesizing aluminum alkoxide by hydrolysis without pulverizing alumina, deflocculating with acid and then subjecting to a concentration step.

In recent years, fine alumina hydrate powder such as boehmite has come to be marketed at a relatively low price, and industrially a coating composition for ink jet recording material is produced from such fine alumina hydrate powder. . In this case, the alumina hydrate dispersion or coating solution is prepared from the powder state, but since the solid content concentration is increased, the pH lowers due to the effect of the acid used for peptization, and bronzing tends to occur. .

A technique using an amino alcohol compound for an ink jet recording material is disclosed in JP-A-59-33.
No. 177, No. 62-37181, No. 62-37182.
No. 62-37183, etc.,
These are related to improvement of water resistance and color development, and there is no description about use of alumina hydrate or bronzing.

[0011]

DISCLOSURE OF THE INVENTION An object of the present invention relates to an inkjet recording material coated with an alumina sol coating liquid, and particularly for inkjet recording which has high gloss and excellent ink absorbency and prevents bronzing from occurring during printing. Provide recording material.

[0012]

As a result of sincerity examination, it was found that the above object of the present invention can be achieved by the following means.

(1) In an ink jet recording material in which at least one ink receiving layer containing an alumina hydrate and a water-soluble binder is provided on a support, the ink receiving layer contains alumina hydrate fine powder and water. An inkjet recording material formed by applying an alumina hydrate dispersion obtained by deflocculation with an inorganic acid as a solvent, a water-soluble binder, and an alumina sol coating liquid containing an amino alcohol compound. .

(2) The ink jet recording material as described in (1) above, wherein the secondary particles of the alumina hydrate of the ink receiving layer have an average particle diameter of 140 to 250 nm.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The alumina hydrate fine powder used in the present invention is Al ₂ O ₃
· NH represented by ₂ configuration formula O (n = 1~3). n is 1
Represents the alumina hydrate having a boehmite structure, and n is greater than 1 and less than 3 represents the alumina hydrate having a pseudo-boehmite structure. Obtained by a known production method such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, hydrolysis of aluminate, etc., and powdered by gelation or spray drying of boehmite sol The commercially available product is available from Sasol, Martinswer, and the like.

The average particle size of the primary particles of the alumina hydrate of the present invention is 100 nm or less, preferably 5 to 50 nm, more preferably 8 to 30 nm. The average particle diameter of the primary particles was determined by observing the dispersed particles with an electron microscope, and determining the diameter of a circle equal to the projected area of each of 100 particles existing in a certain area as the particle diameter.

The average particle size of the secondary particles of the hydrated alumina of the present invention is preferably 140 to 250 nm, more preferably 150 to 200 nm. The above range further improves ink absorbency and surface gloss. The average particle size of the secondary particles of the present invention is measured by a laser diffraction / scattering type particle size distribution measuring device obtained by diluting a dispersion of alumina hydrate to a solid content concentration of 2% or less. The particle size of the secondary particles is governed by the dispersibility of the alumina hydrate fine powder, but can be adjusted to some extent by the addition amount of the peptizer and the solid content concentration.

The fine alumina hydrate powder used in the present invention is peptized with an inorganic acid using water as a solvent. As the inorganic acid as a deflocculant, known acids such as hydrochloric acid, nitric acid and sulfuric acid are used. Nitric acid is particularly preferable. Conventionally, organic acids such as acetic acid and lactic acid have been used as peptizers for alumina in addition to inorganic acids, but it is preferable not to use these organic acids in the present invention. It has been found that the use of an organic acid as a deflocculant adversely affects the surface quality at the time of low-temperature drying at the time of ink-receptive coating, ink absorbency and bronzing. The addition amount of the inorganic acid is preferably 10 to 100 mmol, particularly 20 to 60, based on 100 g of Al ₂ O ₃ of alumina hydrate.
mmol is more preferred.

To disperse the alumina hydrate dispersion used in the present invention, a known dispersing device such as a tooth blade type dispersing machine, a propeller blade type dispersing machine, a high pressure homogenizer, an ultrasonic dispersing machine and a bead mill is used. . The peptizer may be added before or after adding the alumina hydrate fine powder to water, or may be added at the same time.

The solid content concentration of the alumina hydrate dispersion liquid used in the present invention is generally 10 to 35% by mass in terms of Al ₂ O ₃ , but 20 to 30% by mass is preferable. Within the above range, the coating solution is stable, and good surface quality can be obtained without coating unevenness or cracks in the coating layer during coating and drying.

The alumina sol coating liquid of the present invention contains an amino alcohol compound. By adding the amino alcohol compound to the alumina sol coating solution, the coating property is improved and the occurrence of bronzing is prevented. Amino alcohol has the effect of appropriately increasing the pH of the alumina sol coating solution and accompanying the prevention of the aggregation of alumina hydrate fine particles, and easily causes aggregation or thickens caustic soda, caustic potash, ammonia, borax, etc. This is an effect not found in general alkalis. Further, when the alumina sol coating liquid is applied on the support and dried at a low temperature, gelation of the coating layer is promoted, a surface quality without coating unevenness is obtained, and the coating property is improved.

As the amino alcohol compound used in the present invention, conventionally known compounds are used. Those represented by the following general formula are particularly preferred.

[0023] {N- (R1) (R2) (R3)} <General formula>

In the chemical formula 1, at least one of R1, R2 and R3 represents an alkyl group in which at least one hydrogen is replaced by a hydroxyl group, and the other is selected from the group consisting of a hydrogen atom, an alkyl group and an aminoethyl group. Indicates an atom or atomic group.

The amount of the amino alcohol compound added is 0.1 to 5 parts by mass, preferably 0.5 to 2.5 parts by mass, based on 100 parts by mass of Al ₂ O ₃ of the alumina hydrate. .

The aminoalcohol compounds used in the present invention include, for example, monooxymonoamines, monoamine polyhydric alcohols, oxypolyhydric amines and the like. Specific examples are monoethanolamine, diethanolamine, triethanolamine, Monoisopropanolamine, N-methylmonoethanolamine, N-ethylmonoethanolamine, N-methylmonoisopropanolamine, N, N-dimethylmonoethanolamine, N, N
-Diethylmonoethanolamine, 2-ethylaminoethanol, Nn-butylmonoethanolamine, N-
n-butyldiethanolamine, Nt-butylmonoethanolamine, Nt-butyldiethanolamine,
Examples thereof include N- (β-aminoethyl) -ethanolamine.

A water-soluble binder is used in the alumina sol coating liquid of the present invention. In using the water-soluble binder, it is important that the water-soluble binder does not swell and block the voids during initial penetration of the ink. From this viewpoint, a water-soluble binder having a low swelling property at around room temperature is preferable. Used. Particularly preferred water-soluble binders are fully 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.

As the cation-modified polyvinyl alcohol, for example, as described in JP-A-61-10483, primary to tertiary amino groups and quaternary ammonium groups are added to the main chain or side chain of polyvinyl alcohol. It is a polyvinyl alcohol.

Further, other water-soluble binders can be used in combination, but it is preferably 20% by mass or less with respect to polyvinyl alcohol.

In the present invention, it is preferable to use a crosslinking agent (hardening agent) together with the above water-soluble binder. Specific examples of the cross-linking agent include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,
3,5 triazine, compound having reactive halogen as described in US Pat. No. 3,288,775, divinyl sulfone, compound having reactive olefin as described in US Pat. No. 3,635,718, US patent 2nd, 73
N-methylol compounds as described in US Pat. No. 2,316, isocyanates as described in US Pat. No. 3,103,437, US Pat. Nos. 3,017,280 and 2,983.
No. 611, aziridine compounds, US Pat. No. 3,100,704, carbodiimide compounds, US Pat. No. 3,091,537, epoxy compounds, mucochloric acid, halogen carboxaldehydes, There are dioxane derivatives such as dihydroxy dioxane, chromium alum, zirconium sulfate, inorganic cross-linking agents such as boric acid and borate, and these may be used alone or in combination of two or more. Among these, boric acid or borate is particularly preferable.

The alumina sol coating layer of the present invention preferably contains a cationic compound for the purpose of improving water resistance. As the cationic compound, a cationic polymer,
Water-soluble metal compounds may be mentioned.

Examples of the cationic compound used in the present invention include cationic polymers and water-soluble metal compounds. Examples of the cationic polymer include polyethyleneimine, polydiallylamine, polyallylamine, JP-A-59-20696, JP-A-59-33176, and JP-A-59-33176.
9-33177, 59-155088, 60-
11389, 60-49990 and 60-838.
No. 82, No. 60-109894, No. 62-19849.
No. 3, No. 63-49478, No. 63-115780.
No. 63-280681, JP-A-1-40371.
Polymers having a primary to tertiary amino group and a quaternary ammonium salt group described in JP-A Nos. 6-234268, 7-125411, 10-193776, etc. are preferably used. The molecular weight of these cationic polymers is
About 5,000 to 100,000 is preferable.

The amount of these cationic polymers used is 1 to 10% by mass, preferably 2 to 7% by mass, based on the alumina hydrate fine particles.

Examples of the water-soluble metal compound used in the present invention include water-soluble polyvalent metal salts. Examples thereof include water-soluble salts of metals selected from calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, magnesium, tungsten and molybdenum. 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, chloride Cupric, ammonium (II) chloride dihydrate, copper sulfate, cobalt chloride,
Cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel ammonium ammonium hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum sulfite, Aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate,
Ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, zinc phenolsulfonate, zirconium acetate , Zirconium chloride, zirconium chloride octahydrate, zirconium hydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate,
Magnesium citrate nonahydrate, sodium phosphotungstate, sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, etc. To be

Further, examples of the cationic compound include a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer. The basic polyaluminum hydroxide compound has the following main formulas 1 and 2
Or 3 and, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [A
l ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ ] ⁵⁺ [Al ₂₁
It is a water-soluble polyaluminum hydroxide which stably contains basic and high molecular weight polynuclear condensed ions such as (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 marketed by 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 commercially available products can be used as they are,
Some have an inappropriately low pH, and in that case, the pH can be adjusted appropriately before use.

In the present invention, the content of the water-soluble metal compound in the alumina coating layer is 0.1 g / m ^{2 to} 10 g /
m ^2, preferably from ^{0.2g / m 2 ~5g / m 2} .

Two or more of the above-mentioned cationic compounds can be used in combination. For example, a cationic polymer and a water-soluble metal compound may be used together.

In the present invention, the alumina sol coating layer further comprises a coloring agent, a coloring pigment, an ink dye fixing agent, an ultraviolet absorber, an antioxidant, in addition to the surfactant and the hardener.
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.

In the present invention, at least one ink receiving layer containing an alumina hydrate and a water-soluble binder is provided on the support, but in addition to this, at least one layer of a colloidal porous inorganic fine particle other than the alumina hydrate is used. A layer containing silica, fumed silica, alumina or the like may be provided.

[0043] In the present invention, the total coating amount of the alumina hydrate and a water-soluble binder content of the ink receiving layer is preferably from 10g / m ² ~50g / m ² on a dry solid content, more preferably 18 g / m ² ~ It is 40 g / m ² . When a porous inorganic fine particle-containing layer other than alumina hydrate is applied in addition to the ink receiving layer containing alumina hydrate and a water-soluble binder, the coating amount is 15 g in total of the dry solid content of each layer. / m ² ~50g / m ^2, and more preferably from ^{20g / m 2 ~40g / m 2} .

Examples of the support used in the present invention include water-absorbent supports such as general paper, art paper and coated paper, synthetic paper, polyester resin such as polyethylene terephthalate, diacetate resin, triacetate resin, acrylic resin and polycarbonate resin. , A plastic resin film such as polyvinyl chloride, a polyimide resin, cellophane, and celluloid, and a water-resistant support such as a resin-coated paper in which a polyolefin resin is laminated on both sides of the paper. In particular, resin-coated paper is preferably used.

The base paper constituting the resin-coated paper preferably used in the present invention is not particularly limited, and commonly used paper can be used, but more preferably, it is smooth as used for a photographic support. Raw base paper is preferred. As the pulp constituting the raw 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, a filler, an antistatic agent, an optical brightening agent, which is generally used in papermaking,
Additives such as 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. ˜250 g / m ² is preferred.

As the resin for the resin-coated paper, a polyolefin resin or a resin curable with an electron beam can be used.
The polyolefin resin is a homopolymer of olefins such as low-density polyethylene, high-density polyethylene, polypropylene, polybutene, and polypentene, or a copolymer of two or more olefins such as ethylene-propylene copolymer and a mixture thereof. Various densities and melt viscosity indexes (melt indexes) can be used alone or in combination.

In the resin of the 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, stearic acid. Aluminum, fatty acid metal salts such as magnesium stearate, antioxidants such as Irganox 1010 and Irganox 1076, blue pigments and dyes such as Cobalt Blue, Ultramarine Blue, Cecilian Blue, Phthalocyanine Blue, Cobalt Violet, Fast Violet, Manganese Purple It is preferable to add various additives such as magenta pigments and dyes, fluorescent whitening agents, and ultraviolet absorbers in an appropriate combination.

The resin-coated paper, which is a support preferably used in the present invention, is produced by a so-called extrusion coating method in which a heat-melted resin is cast in the case of a polyolefin resin on a running base paper, and both surfaces of the resin are coated. Is covered by. In the case of a resin that is cured by an electron beam, the resin is applied by a commonly used coater such as a gravure coater or a blade coater, and then the resin is irradiated with an electron beam to cure and coat the resin. Further, it is preferable to perform activation treatment such as corona discharge treatment or flame treatment on the base paper before coating the base paper with the resin. The surface (surface) of the support to which the ink receiving layer is applied has a glossy surface, a matte surface or the like depending on the application, and the glossy surface is particularly predominantly used. It is not necessary to coat the back surface with a resin, but it is preferable to coat the resin from the viewpoint of preventing curling. The back surface is usually a matte surface, and the front surface or both front and back surfaces can be subjected to activation treatment such as corona discharge treatment and flame treatment, if necessary. The thickness of the resin coating layer is not particularly limited, but it is generally coated on the surface or both front and back sides with a thickness of 5 to 50 μm.

In the present invention, a known coating method can be used as the coating method of the alumina sol coating liquid. For example, there are a slide bead method, a curtain method, an extrusion method, an air knife method, a roll coating method, a rod bar coating method and the like.

In the present invention, the film surface temperature is 20 ° C. in the step of applying the alumina sol coating liquid on the support and then drying it.
After cooling, it is preferable to dry after cooling. By drying at a low temperature, a void structure is formed in the gelled state of the alumina hydrate coating layer, so that an inkjet recording material having excellent coating properties and ink absorbability can be obtained.

In the present invention, the ink jet recording material may be provided with an ink receiving layer containing fine particles of hydrated alumina and, on the layer, a protective layer for improving scratch resistance. Examples of the protective layer include a porous layer containing inorganic fine particles such as colloidal silica and spherical alumina.

When the coating solution for the ink receiving layer is applied to the film support or resin-coated paper, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, plasma treatment or the like is preferably carried out prior to coating.

In the present invention, when a film or resin-coated paper which is a water resistant support is used, it is preferable to provide a primer layer mainly containing a natural polymer compound or a synthetic resin on the surface on which the ink receiving layer is provided. . The transparency of the ink receiving layer is further improved by coating the ink receiving layer containing the inorganic fine particles of the present invention on the primer layer, then cooling and drying at a relatively low temperature.

The primer layer provided on the water resistant support is mainly composed of natural polymer compounds such as gelatin and casein and synthetic resins. As such a synthetic resin, an acrylic resin,
Polyester resin, vinylidene chloride, vinyl chloride resin,
Examples thereof include vinyl acetate resin, polystyrene, polyamide resin and polyurethane resin.

The above-mentioned primer layer is formed on the support by 0.01
It is provided with a film thickness (dry film thickness) of ˜5 μm. It is preferably in the range of 0.05 to 5 μm.

Various back coat layers can be coated on the support of the present invention for the purposes of writing, antistatic properties, transportability, curl prevention and the like. In the back coat layer, an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder,
A latex, a pigment, a curing agent, a surfactant and the like can be contained in an appropriate combination.

[0059]

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.
In addition, part and% show a mass part and the mass%.

Example 1 <Preparation of Polyolefin Resin Coated Paper Support> A 1: 1 mixture of a bleached hardwood kraft pulp (LBKP) and a bleached softwood sulfite pulp (NBSP) was beaten to 300 ml under Canadian Standard Freeness, and the pulp was pulped. A slurry was prepared. 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 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 polyolefin resin-coated paper. Low-density polyethylene with a density of 0.918 g / cm ^{3 on} paper
A polyethylene resin composition in which 10% by mass of anatase-type titanium dioxide was uniformly dispersed in 100% by mass of resin was melted at 320 ° C., and extrusion coding was performed so that the thickness was 35 μm at 200 m / min. Extrusion coating was performed using a surface-modified cooling roll. High density polyethylene resin 70 with a density of 0.962 g / cm ^{3 on} the other surface
30 parts by weight and low density polyethylene resin having a density of 0.918
Similarly, a part by mass of the blended resin composition was melted at 320 ° C., extrusion-coated to a thickness of 30 μm, and extrusion-coated using a roughened cooling roll.

A high-roughened corona discharge treatment was applied to the surface of the polyolefin resin-coated paper which had been subjected to a micro-roughening treatment, and then a primer layer having the following composition was coated and dried so that the gelatin content was 50 mg / m ² to prepare a support. did.

[0062] <Primer layer> 100 parts of lime-processed gelatin Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chrome Alum 10 copies

A coating solution comprising the following alumina sol coating composition was applied onto the primer layer of the above support by a slide bead coating device and dried. Alumina sol coating layer is solid 3
It was applied and dried so as to be 5 g / m ² .

<Alumina sol coating composition> Pseudo-boehmite dispersion liquid (solid content concentration 25% in terms of Al ₂ O ₃ ) 100 parts (average particle diameter of primary particles 14 nm, average particle diameter of secondary particles 170 nm) Boric acid 0. 3 parts Polyvinyl alcohol 12 parts (Saponification degree 88%, average degree of polymerization 3500) N- (β-aminoethyl) ethanolamine 0.75 parts Surfactant 0.2 parts (Product name: SWAM AM-2150, Nippon Surfactant Distilled water is added to the above additive to obtain a solid content concentration of 20% and a pH of 5.8.
To obtain a coating solution of alumina sol. The above pseudo-boehmite dispersion liquid was prepared by adding nitric acid as a peptizer in distilled water to 100 in terms of Al ₂ O _3.
It was added in advance so that it would be 30 mmol with respect to g,
Pseudo-boehmite powder (DISPERAL HP14, manufactured by Sasol) was added to this solution while stirring with a dispersion device (manufactured by Tokushu Kika Kogyo Co., Ltd., Hibis Dispermix), and stirring was continued for another 60 minutes after the addition.

The drying conditions after coating are shown below. 3 at 5 ° C
After cooling for 0 seconds, the total solid content concentration is 90% by mass at 45 ° C.
It was dried at 10% RH and then at 35 ° C. 10% RH.

The following evaluations were performed on the ink jet recording sheet prepared as described above. The results are shown in Table 1.

<Coatability> The condition of the coated surface was visually observed and evaluated. ◯: No coating unevenness, cracks or surface defects such as lines are observed. Δ: Surface defects such as coating unevenness and cracks are slightly observed. X: The degree of coating unevenness and cracking is severe.

<Glossy blank part> The glossiness of the white paper part was observed by oblique light and evaluated according to the following criteria. ◯: Has a high glossy feeling similar to that of a color photograph. Δ: There is a glossiness similar to that of art and coated paper. X: There is a sinking glossy feeling similar to that of high-quality paper.

<Bronzing> Cyan and blue solid portions were printed with a commercially available inkjet printer (PM880C, manufactured by Seiko Epson Corp.), and the presence or absence of bronzing was visually evaluated. ◯: No bronzing occurred Δ: Bronzing was slightly observed. ×: Bronzing occurred

<Ink Absorption> Solid inks of 100% and 70% of red, green, blue, and heavy colors are printed with a commercially available ink jet printer (PM880C manufactured by Seiko Epson Corporation), and PPC paper is printed immediately after printing. Then, the amount of ink transferred to the PPC paper was visually observed. Evaluated according to the following criteria: No transfer occurs. Δ: Transfer a little. ×: Transfer is large and cannot be actually used

Example 2 An ink jet recording material of Example 2 was obtained in the same manner as in Example 1 except that N-methylethanolamine was used instead of the amino alcohol compound of Example 1. Table 1 shows the evaluation results
Shown in.

Example 3 An ink jet recording material of Example 3 was obtained in the same manner as in Example 1 except that the amino alcohol compound of Example 1 was replaced with Nt-butylethanolamine. The evaluation results are shown in Table 1.

Example 4 An ink jet recording material of Example 4 was obtained in the same manner as in Example 1 except that the amino alcohol compound of Example 1 was replaced with Nt-butyldiethanolamine. The evaluation results are shown in Table 1.

Comparative Example 1 An ink jet recording material of Comparative Example 1 was obtained in the same manner as in Example 1 except that the peptizing agent of the pseudo-boehmite dispersion liquid of Example 1 was replaced with the same amount of acetic acid. The evaluation results are shown in Table 1.

Comparative Example 2 An ink jet recording material of Comparative Example 2 was obtained in the same manner as in Example 1 except that the amino alcohol compound of Example 1 was removed and the pH of the alumina sol coating liquid of Example 1 was adjusted with caustic soda. It was The evaluation results are shown in Table 1.

Comparative Example 3 An ink jet recording material of Comparative Example 3 was prepared in the same manner as in Example 1 except that the amino alcohol compound of Example 1 was removed and the pH of the alumina sol coating solution of Example 1 was adjusted with borax. Obtained. The evaluation results are shown in Table 1.

Comparative Example 4 An ink jet recording material of Comparative Example 4 was obtained in the same manner as in Example 1 except that the amino alcohol compound of Example 1 was omitted. The pH of the coating liquid was 4.0. Table 1 shows the evaluation results
Shown in.

[0078]

[Table 1] ──────────────────────────────────── Sample coatability Gloss of white paper Bronzing Ink absorption ──────────────────────────────────── Example 1 ○ ○ ○ ○ Example 2 ○ ○ ○ ○ Example 3 ○ ○ ○ ○ Example 4 ○ ○ ○ ○ ──────────────────────────────────── Comparative Example 1 × ○ × △ Comparative Example 2 △ × △ ○ Comparative Example 3 × − − − Comparative Example 4 △ ○ × △ ────────────────────────────────────

Results: As is apparent from the results of Examples 1 to 4, the alumina sol dispersion liquid containing an inorganic acid as a peptizer and the alumina coating liquid of the present invention containing an amino alcohol compound were applied with good surface quality. Ink jet recording materials using the same exhibit bronzing prevention, high gloss and excellent ink absorbency. In Comparative Example 1, the peptizer was replaced with an organic acid, but the coatability and ink absorbency were insufficient, and no effect of preventing bronzing was observed. Comparative Example 2 is a case in which amino alcohol was removed and the pH of the coating solution was adjusted with caustic soda. Thickening and agglomeration of the coating solution were observed, which resulted in a decrease in gloss and deterioration of surface quality, and also for bronzing. The effect was insufficient. Comparative Example 4 is a case in which amino alcohol was removed, and the effect on coating properties and ink absorbency was insufficient, and no preventive effect on bronzing was observed. In Comparative Example 3, the amino alcohol was removed and the pH of the coating liquid was adjusted with borax, and the thickening of the alumina coating liquid was so severe that it was not possible to prepare a sample that would cause printing.

[0080]

INDUSTRIAL APPLICABILITY The present invention relates to an ink jet recording material coated with an alumina sol coating liquid, which provides an ink jet recording material having high gloss and excellent ink absorbency and preventing bronzing during printing.

Claims (2)

[Claims] 1. A recording material for ink jet comprising at least one ink receiving layer containing an alumina hydrate and a water-soluble binder on a support, wherein the ink receiving layer comprises alumina hydrate fine powder and water as a solvent. An inkjet recording material formed by applying an alumina hydrate dispersion obtained by deflocculation with an inorganic acid, a water-soluble binder, and an alumina sol coating liquid containing an amino alcohol compound. 2. The ink jet recording material according to claim 1, wherein the average particle diameter of secondary particles of alumina hydrate of the ink receiving layer is 140 to 250 nm.