JP2022118827A - Inkjet recording material - Google Patents

Abstract

To provide an inkjet recording material that yields high gloss and high print density, and is resistant to roller marks caused by oil bleeding from the paper feed roller of an inkjet printer.SOLUTION: The inkjet recording material has an ink-receiving layer containing mainly an inorganic fine particle having an average secondary particle size of 500 nm or less on both sides of a non-absorptive support, and has an outermost layer containing a polyolefin particle having an average primary particle size of 0.1 to 0.7 μm by 5 to 25 mg/m2 on at least one ink-receiving layer.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to an inkjet recording material which provides high gloss and high print density, and which hardly causes roller marks due to bleeding of oil from a paper feed roller of an inkjet printer.

As a recording material used in the inkjet recording method, a pigment such as amorphous silica and polyvinyl alcohol are coated on a non-absorbing support such as a paper support or a resin film or a polyolefin resin-coated paper. Recording materials having a porous ink-receiving layer containing a water-soluble binder such as

2. Description of the Related Art In recent years, there has been known an inkjet recording material that uses ultrafine inorganic fine particles as a pigment and has a photo-like gloss. Specifically, it is known to use inorganic fine particles such as vapor-phase silica and wet-process silica pulverized and dispersed to an average secondary particle diameter of 500 nm or less as a pigment component of an ink receiving layer. No. 2000-211235, JP-A-2000-309157, etc. use examples of gas-phase silica, JP-A-9-286165, JP-A-10-181190, etc., pulverized sedimentation silica An example of the use of pulverized gel method silica is disclosed in Japanese Patent Application Laid-Open No. 2001-277712. Further, recording materials using alumina or alumina hydrate are disclosed in JP-A-62-174183, JP-A-2-276670, JP-A-5-32037 and JP-A-6-199034. ing. When the ink-receiving layer mainly contains fine inorganic fine particles, a porous ink-receiving layer with high gloss and excellent ink absorbability can be obtained.

When printing, for example, a photographic image using an inkjet printer on an inkjet recording material having such an ink-receiving layer on both sides of a non-absorbent support, when one side is printed and then the other side is printed, There was a problem that traces (roller traces) of the contact of the paper feed roller remained or scratches occurred. For example, as described in Japanese Patent Application Laid-Open No. 2011-256347 (Patent Document 1), such a problem can be solved by imparting appropriate flexibility to the roller body. This is improved by including a large amount of oil in the composition. However, the oil contained in the paper feed roller bleeds, and the bleeding oil is transferred to the surface of the ink jet recording material, which may cause roller marks different from the roller marks described above. had been

On the other hand, Japanese Patent Application Laid-Open No. 2006-256157 (Patent Document 2) discloses that an inkjet recording material containing polyolefin particles of 3 to 22 μm and inorganic fine particles in the outermost ink-receiving layer has color developability and glossiness, It also describes that the scratch resistance during transport to a printer can be improved. Further, in Japanese Patent Application Laid-Open No. 2008-126550 (Patent Document 3), by providing a surface layer containing organic fine particles having a particle diameter of 15 nm or more and 400 nm or less on an ink receiving layer, the pigment ink has excellent scratch resistance, An ink-jet recording material that is resistant to serrated roller marks is described. On the other hand, an ink-jet recording material having an ink-receiving layer containing natural organic fine particles as the outermost layer on the other side is described as an ink-jet recording material in which marks of a pick-up roller of a printer are not conspicuous on the printing surface and which is capable of double-sided printing. . However, even these ink jet recording materials are not sufficiently effective against roller marks caused by oil bleeding from the paper feed roller, and further improvements have been desired.

JP 2011-256347 A JP 2006-256157 A JP 2008-126550 A Japanese Patent Application Laid-Open No. 2004-351771

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording material which is highly glossy and provides high printing density, and is less likely to cause roller marks due to bleeding of oil from the rubber composition constituting the paper feed roller.

The above objects of the present invention are basically achieved by the following inventions.
An inkjet recording material having ink-receiving layers mainly containing inorganic fine particles having an average secondary particle size of 500 nm or less on both sides of a non-absorbing support, wherein at least one of the ink-receiving layers has an average primary particle size of 0. An ink jet recording material characterized by having an outermost layer containing 5 to 25 mg/m ² of polyolefin particles of 1 to 0.7 µm.

According to the present invention, it is possible to provide an ink jet recording material which is highly glossy and provides a high print density, and is less susceptible to roller marks caused by bleeding of oil from the rubber composition constituting the paper feed roller.

The present invention will be described in detail below.

The inkjet recording material of the present invention is an inkjet recording material having ink-receiving layers mainly containing inorganic fine particles having an average secondary particle diameter of 500 nm or less on both sides of a non-absorbent support, wherein at least one of the ink-receiving layers is an ink-receiving layer. It has an outermost layer containing 5 to 25 mg/m ² of polyolefin particles having an average primary particle size of 0.1 to 0.7 μm.

The non-absorbent support contained in the ink jet recording material of the present invention includes resin films such as polyethylene, polypropylene, polyvinyl chloride, diacetate resin, triacetate resin, cellophane, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, etc., or polyolefin. Resin-coated paper and the like represented by resin-coated paper are exemplified. The thickness of these non-absorbent supports is preferably 50 to 300 μm from the viewpoint of handleability.

The non-absorbent support may have an undercoat layer mainly composed of a natural polymer compound or a synthetic resin on the surface on which the ink-receiving layer is to be formed. Examples of the undercoat layer include an undercoat layer mainly composed of gelatin. The coating amount of the undercoat layer is not particularly limited, but the solid content coating amount is preferably in the range of 0.005 to 2.0 g/m ² , more preferably in the range of 0.01 to 1.0 g/m ² . A range of 0.02 to 0.5 g/m ² is particularly preferred.

In the present invention, the ink-receiving layer on the non-absorbent support mainly contains inorganic fine particles having an average secondary particle size of 500 nm or less. Here, containing mainly inorganic fine particles means that inorganic fine particles are contained in an amount of 50% by mass or more, preferably 60 to 96% by mass, based on the total solid content of the ink-receiving layer. This makes it possible to obtain an inkjet recording material having excellent ink absorbability. The inorganic fine particles contained in the ink-receiving layer are preferably hydrophilic inorganic fine particles, and examples thereof include various known fine particles such as amorphous synthetic silica, alumina, alumina hydrate, calcium carbonate, magnesium carbonate, and titanium dioxide. However, amorphous synthetic silica, alumina or alumina hydrate is preferred in that high print density and excellent image sharpness can be obtained.

Amorphous synthetic silica can be broadly classified into wet process silica, gas phase process silica, and others according to the manufacturing method. Wet-process silica is further classified into precipitation-process silica, gel-process silica, and sol-process silica according to the production method. Precipitation silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions, and the grown silica particles are aggregated and precipitated, then filtered, washed with water, dried, pulverized, and classified to produce products. Precipitated silica is commercially available, for example, from Tosoh Silica Corporation as NipSeal (registered trademark). Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During aging, fine particles dissolve and re-precipitate to bind other primary particles together, so that well-defined primary particles disappear and form relatively hard agglomerated particles with an internal void structure. For example, it is commercially available from Tosoh Silica Corporation as Nip Gel (registered trademark). Sol silica, also called colloidal silica, is obtained by heating and aging a silica sol obtained by metathesis of sodium silicate with an acid or the like or through an ion-exchange resin layer, for example, Snowtex (registered trademark) from Nissan Chemical Co., Ltd. It is commercially available.

Vapor-phase silica is also called a dry method as opposed to a wet method, 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 can also be used alone or with silicon tetrachloride. It can be used in a mixed state with Vapor-phase silica is commercially available from Nippon Aerosil Co., Ltd. as AEROSIL (registered trademark) and from Tokuyama Corporation as Leorosil (registered trademark).

Vapor-phase silica is preferably used in the ink-receiving layer of the inkjet recording material of the present invention. The vapor phase silica contained in the ink-receiving layer preferably has an average primary particle size of 30 nm or less, more preferably an average primary particle size of 3 to 15 nm and a BET specific surface area of 200 m ² /g or more. Particularly preferred are those having a particle diameter of 3 to 10 nm and a specific surface area of 250 to 500 m ² /g as determined by the BET method. The average primary particle size as used in the present invention is the diameter of a circle equal to the projected area of each of 100 primary particles existing within a certain area obtained by electron microscopic observation of fine particles, and the average value of the particle sizes is obtained. is. The BET method as used in the present invention is one of methods for measuring the surface area of powder by the vapor phase adsorption method, and is a method for determining the total surface area of 1 g of a sample, that is, the specific surface area, from the adsorption isotherm. Nitrogen gas is generally used as the adsorbed gas, and the method of measuring the amount of adsorption from changes in the pressure or volume of the gas to be adsorbed is most often used. The Brunauer-Emmett-Teller equation, which is called the BET equation and is widely used to determine the surface area, is the most famous for expressing the isotherm of multimolecular adsorption. The amount of adsorption is determined based on the BET formula and multiplied by the area occupied by one adsorbed molecule on the surface to obtain the surface area.

The gas phase method silica can preferably be used when dispersed in the presence of a cationic compound. In the present invention, the average secondary particle size of fumed silica is 500 nm or less, more preferably 10 to 300 nm. This makes it possible to obtain an ink-receiving layer with excellent glossiness. As a method for obtaining fumed silica having an average secondary particle size of 500 nm or less, fumed silica and a dispersion medium are premixed by ordinary propeller stirring, turbine type stirring, homomixer type stirring, etc., followed by ball milling, Dispersion is preferably carried out using a media mill such as a bead mill or a sand grinder, a pressure disperser such as a high pressure homogenizer or an ultrahigh pressure homogenizer, an ultrasonic disperser, a thin film swirling disperser, or the like. The average secondary particle size referred to in the present invention refers to the number median size measured using a laser scattering particle size distribution analyzer (for example, LA920 manufactured by Horiba, Ltd.).

In the present invention, wet process silica can also be preferably used. As the wet-process silica having an average secondary particle size of 500 nm or less contained in the ink-receiving layer, precipitation-process silica or gel-process silica is preferable, and precipitation-process silica is particularly preferable. The average primary particle size of the wet-process silica used in the present invention is preferably 50 nm or less, more preferably 3 to 40 nm. Further, the average secondary particle size of the wet-process silica is more preferably 20 to 300 nm from the viewpoint of obtaining an ink-receiving layer with excellent glossiness.

Wet-process silica can preferably be used after being dispersed and pulverized in the presence of a cationic compound. As a pulverization method, a wet dispersion method in which silica dispersed in an aqueous medium is mechanically pulverized can be preferably used. A preferred method for pulverizing the wet-process silica used in the present invention will be described. First, wet-process silica particles and a cationic compound are mixed in a dispersion medium mainly composed of water, and at least one dispersing device such as a sawtooth blade dispersing machine, a propeller vane dispersing machine, or a rotor-stator dispersing machine is used. to obtain a silica predispersion. If necessary, an appropriate low boiling point solvent or the like may be added to the aqueous dispersion medium. The solid content concentration of the silica pre-dispersion liquid is preferably high, but if the concentration becomes too high, dispersion becomes impossible. The silica pre-dispersion is then preferably subjected to mechanical means with higher shear forces to comminute the silica particles. As the mechanical means, known methods can be employed, for example, media mills such as ball mills, bead mills, and sand grinders, pressure-type dispersers such as high-pressure homogenizers and ultra-high-pressure homogenizers, ultrasonic dispersers, thin-film swirling dispersers, and the like. can be used.

A cationic polymer can be preferably used as the cationic compound used for dispersing or pulverizing the gas-phase silica and the wet-process silica. Examples of cationic polymers include polyethyleneimine, polydiallylamine, polyallylamine, alkylamine polymers, JP-A-59-20696, JP-A-59-33176, JP-A-59-33177, JP-A-59-33177 and JP-A-59-33177. 59-155088, JP-A-60-11389, JP-A-60-49990, JP-A-60-83882, JP-A-60-109894, JP-A-62-198493 , JP-A-63-49478, JP-A-63-115780, JP-A-63-280681, JP-A-1-40371, JP-A-6-234268, JP-A-7-125411 Polymers having primary to tertiary amino groups and quaternary ammonium bases described in JP-A-10-193776 and the like are preferably used. In particular, a diallylamine derivative is preferably used as the cationic polymer. In terms of dispersibility and dispersion viscosity, the weight average molecular weight of these cationic polymers is preferably about 2,000 to 100,000, more preferably about 2,000 to 30,000.

Alumina can also be preferably used in the present invention. As the alumina contained in the ink-receiving layer, γ-alumina, which is a γ-type crystal of aluminum oxide, is preferable, and δ-group crystal is particularly preferable. γ-alumina can be made to have primary particles as small as about 10 nm, but it is usually produced by pulverizing secondary particle crystals of several thousand to tens of thousands of nanometers using ultrasonic waves, high-pressure homogenizers, counter-collision jet pulverizers, etc. can be used. The average secondary particle size of alumina is 500 nm or less, more preferably 20 to 300 nm.

Alumina hydrate contained in the ink-receiving layer is represented by a constitutive formula of Al ₂ O ₃ ·nH ₂ O (n=1 to 3). Alumina hydrate used in the present invention can be obtained by known production methods such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, hydrolysis of aluminate, and the like. The average secondary particle size of the alumina hydrate used in the present invention is 500 nm or less, more preferably 20 to 300 nm.

The above alumina and alumina hydrate are preferably dispersed with a known dispersant such as acetic acid, lactic acid, formic acid and nitric acid.

Further, in the present invention, two or more kinds of inorganic fine particles selected from the inorganic fine particles having an average secondary particle diameter of 500 nm or less can be used in combination. For example, combined use of finely pulverized wet-process silica and vapor-phase silica, combined use of finely-ground wet-process silica and alumina or alumina hydrate, combined use of vapor-phase process silica and alumina or alumina hydrate, etc. mentioned.

In the present invention, the ink-receiving layer described above preferably contains a hydrophilic binder. As such a hydrophilic binder, polyvinyl alcohol, polyethylene glycol, starch, dextrin, carboxymethyl cellulose, polyvinylpyrrolidone, polyacrylic acid esters, and derivatives thereof are used. Among them, completely or partially saponified polyvinyl alcohol is used. Preferred are those having a degree of saponification of 80% or more. The average degree of polymerization of polyvinyl alcohol is preferably 500-6000, more preferably 1000-5000.

The polyvinyl alcohol mentioned above includes, in addition to general polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, and other polyvinyl alcohol derivatives. One type of polyvinyl alcohol may be used alone, or two or more types may be used in combination.

The content of the hydrophilic binder in the ink-receiving layer is preferably 3 to 80% by mass, more preferably 5 to 50% by mass, based on the inorganic fine particles having an average secondary particle size of 500 nm or less. This makes it possible to obtain an ink-receiving layer with excellent ink absorbability.

In the present invention, the ink-receiving layer preferably contains a cross-linking agent in addition to the hydrophilic binder described above. As the cross-linking agent, those known as cross-linking agents for hydrophilic binders can be used. When polyvinyl alcohol is used as the hydrophilic binder, boric acid or borates are particularly preferred. Moreover, when polyvinyl alcohol contains a highly active modifying group, a known cross-linking agent may be used according to the modifying group. The amount of the cross-linking agent added is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass, relative to the hydrophilic binder.

In the present invention, the ink-receiving layer preferably has a dry coating amount of 16 g/m ² or more, particularly preferably 18 g/m ² or more, in order to ensure the ink absorption speed and ink absorption capacity. The upper limit is about 30 g/m ² . Even if the dry coating amount exceeds 30 g/m ² , the print density of the printed image may not be improved.

In the ink jet recording material of the present invention, 5 to 5 polyolefin particles having an average primary particle diameter of 0.1 to 0.7 μm are provided on at least one of the ink receiving layers provided on both sides of the non-absorbent support. It has a top layer containing 25 mg/m ² . As a result, roller traces due to bleeding of oil contained in the paper feed roller can be suppressed, and at the same time, high glossiness and high print density can be obtained.

The above-mentioned roller traces due to bleeding of oil from the paper feed roller are printed on the ink-receiving layer on one side of the non-absorbent support with an inkjet printer capable of double-sided printing, and then printed on the other side. When printing is performed on the ink-receiving layer of , it is expressed on the ink-receiving layer that has been printed for the second time. Become. However, when printing with an inkjet printer capable of double-sided printing, it is troublesome for the user to specify the loading direction of the inkjet recording material. It is desirable to have an outermost layer.

In the present invention, the polyolefin particles contained in the outermost layer refer to particles of aliphatic hydrocarbon polymers containing one or more carbon-carbon double bonds, and specifically include particles of polyethylene, polypropylene, and the like. be done. Commercially available products include Chemipearl (registered trademark) S100 (average primary particle size 0.1 μm), S200 (average primary particle size 0.5 μm), and S500 (average primary particle size 0.7 μm) manufactured by Mitsui Chemicals, Inc. etc. are exemplified and can be suitably used in the present invention.

In the present invention, the outermost layer may contain colloidal silica in addition to the polyolefin particles described above. In that case, it is preferable to add 10 to 50 mg/m ² of colloidal silica to the outermost layer. Colloidal silica is silica synthesized by a sol method, and preferably has an average primary particle size of 10 to 50 nm, more preferably 15 to 45 nm. Within the above range, the glossiness of the blank portion and the adhesiveness to the ink-receiving layer are excellent. As such colloidal silica, Silidol (registered trademark) from Nippon Kagaku Kogyo Co., Ltd., Adelite (registered trademark) AT from ADEKA Corporation, Cataloid (registered trademark) from JGC Catalysts and Chemicals Industry Co., Ltd. Snowtex is commercially available from Nissan Chemical Co., Ltd., and Quatron (registered trademark) is commercially available from Fuso Chemical Industry Co., Ltd.

In the present invention, the ink-receiving layer and the outermost layer may be coated one by one by a sequential coating method (for example, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a reverse coater, etc.), or a multi-layer simultaneous coating method. The effect of the present invention can be obtained by any of the multi-layer coating methods (for example, slide bead coater, slide curtain coater, etc.). Among them, a slide bead coater is preferably used for the ink receiving layer, and a gravure coater is preferably used for the outermost layer.

EXAMPLES The present invention will be described in detail below with reference to examples, but the content of the present invention is not limited to the examples.

(Example 1)
<Production of polyolefin resin-coated paper>
A 1:1 mixture of bleached hardwood kraft pulp (LBKP) and bleached hardwood sulfite pulp (LBSP) was beaten to 300 ml with a Canadian Standard Freeness to prepare a pulp slurry. In addition, 0.5% by mass of alkyl ketene dimer as a sizing agent, 1.0% by mass of polyacrylamide as a strength agent, 2.0% by mass of cationized starch, and polyamide epichlorohydrin resin. 0.5% by mass of the pulp was added and diluted with water to form a 0.2% by mass slurry. This slurry was made into paper with a fourdrinier paper machine so as to have a basis weight of 135 g/m ² , dried and conditioned to obtain a base paper for polyolefin resin-coated paper. The thickness of the paper-made base paper is 130 μm. A polyolefin resin composition in which 10% by mass of anatase titanium is uniformly dispersed in 100% by mass of low-density polyethylene resin having a density of 0.918 g/cm ³ is melted at 320° C. on both sides of the base paper, Extrusion coating was performed to a thickness of 15 μm, and extrusion coating was performed using a cooling roll to obtain a polyolefin resin-coated paper having a thickness of 160 μm.

After subjecting the surfaces (both sides) of the polyolefin resin-coated paper obtained as described above to high-frequency corona discharge treatment, an undercoat layer having the following composition was applied so that gelatin was 0.05 g/m ² , and dried. A support was prepared.

<Undercoat layer>
Lime-processed gelatin 100 parts by mass Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts by mass Chrome alum 10 parts by mass

On each undercoat layer of the polyolefin resin-coated paper prepared as described above, an ink-receiving layer coating liquid 1 having the following composition was applied with a slide bead coater so that the solid content was 23.0 g/m ² , After cooling at 10°C for 20 seconds, it was dried by blowing hot air at 30-55°C.

<Preparation of vapor phase silica dispersion>
After adding 4 parts by mass of dimethyldiallylammonium chloride homopolymer (molecular weight 9000) and 100 parts by mass of vapor-phase silica (average primary particle size 7 nm, specific surface area 300 m ² /g by BET method) to water to prepare a preliminary dispersion. and a high-pressure homogenizer under the condition of 30 MPa twice to prepare a vapor phase silica dispersion having a solid content concentration of 20% by mass. The average secondary particle size of the fumed silica was 135 nm.

<Ink receiving layer coating solution 1>
Gas-phase silica dispersion (as solid content of gas-phase silica) 100 parts by mass Boric acid 4 parts by mass Polyvinyl alcohol (degree of saponification 88%, average degree of polymerization 3500) 23 parts by mass The solid content concentration of the coating liquid is 13 in water. .3% by mass.

On the ink-receiving layer obtained as described above, outermost layer coating liquid 1 having the following composition was applied with a reverse gravure coater so that the solid content was 15 mg/m ² , and hot air at 35°C was blown. An outermost layer was formed to obtain an inkjet recording material of Example 1.

<Outermost layer coating solution 1>
Add polyolefin particles (Chemipearl S200 manufactured by Mitsui Chemicals, Inc., average primary particle size 0.5 μm) to water, stir with a propeller at 700 rpm for 5 minutes, and add water so that the solid content concentration becomes 0.5% by mass. Outermost layer coating liquid 1 was prepared by adjusting.

(Example 2)
In Example 1, the outermost layer coating liquid 1 was applied to each ink-receiving layer so that the solid content of the outermost layer after drying was 5 mg/m ² . No. 2 ink jet recording material was obtained.

(Example 3)
In Example 1, the outermost layer coating liquid 1 was applied to each ink-receiving layer so that the solid content of the outermost layer after drying was 25 mg/m ² . No. 3 inkjet recording material was obtained.

(Example 4)
An inkjet recording material of Example 4 was obtained in the same manner as in Example 1, except that the outermost layer coating liquid 1 applied on each ink-receiving layer was changed to the outermost layer coating liquid 2 below.

<Outermost layer coating solution 2>
Add polyolefin particles (Chemipearl S100 manufactured by Mitsui Chemicals, Inc., average primary particle size 0.1 μm) to water, stir with a propeller at 700 rpm for 5 minutes, and add water so that the solid content concentration becomes 0.5% by mass. Outermost layer coating liquid 2 was prepared by adjusting.

(Example 5)
An inkjet recording material of Example 5 was obtained in the same manner as in Example 1, except that the outermost layer coating liquid 1 applied on each ink-receiving layer was changed to the outermost layer coating liquid 3 below.

<Outermost layer coating solution 3>
Add polyolefin particles (Chemipearl S500 manufactured by Mitsui Chemicals, Inc., average primary particle size 0.7 μm) to water, stir with a propeller at 700 rpm for 5 minutes, and add water so that the solid content concentration becomes 0.5% by mass. Outermost layer coating liquid 3 was prepared by adjusting.

(Example 6)
An inkjet recording material of Example 6 was obtained in the same manner as in Example 1, except that the ink-receiving layer coating solution 1 was changed to the following ink-receiving layer coating solution 2.

<Alumina Dispersion>
2 parts by mass of acetic acid (10% aqueous solution) and 100 parts by mass of γ-alumina powder (average primary particle size: 16 nm, specific surface area: 185 m ² /g) were added to water to prepare a preliminary dispersion, which was then treated with a homogenizer. , to obtain an alumina dispersion having a solid content concentration of 20% by mass. The average secondary particle size of the γ-alumina was 168 nm.

<Ink receiving layer coating liquid 2>
Alumina dispersion (as solid content of alumina) 100 parts by mass Boric acid 0.5 parts by mass Polyvinyl alcohol 8 parts by mass (degree of saponification 88%, average degree of polymerization 3500)
Propylene glycol 4 parts by mass Surfactant 0.3 parts by mass (betaine type; BT9 manufactured by Nippon Surfactant Kogyo Co., Ltd.)
The solid concentration of the coating liquid was adjusted to 19.0% by mass with water.

(Comparative example 1)
An inkjet recording material of Comparative Example 1 was obtained in the same manner as in Example 1, except that the outermost layer was not applied on each ink-receiving layer.

(Comparative example 2)
An inkjet recording material of Comparative Example 2 was obtained in the same manner as in Example 1, except that the outermost layer coating liquid 1 applied on each ink receiving layer was changed to the outermost layer coating liquid 4 below.
<Outermost layer coating solution 4>
Outermost layer coating liquid 4 was prepared by adjusting colloidal silica (Quartron PL3 manufactured by Fuso Chemical Industry Co., Ltd., average primary particle size 35 nm) with water so that the solid content concentration was 0.5% by mass.

(Comparative Example 3)
An inkjet recording material of Comparative Example 3 was obtained in the same manner as in Example 1, except that the outermost layer coating liquid 1 applied on each ink receiving layer was changed to the outermost layer coating liquid 5 below.
<Outermost layer coating solution 5>
Add polyolefin particles (Chemipearl W700 manufactured by Mitsui Chemicals, Inc., average primary particle size 1.0 μm) to water, stir with a propeller at 700 rpm for 5 minutes, and add water so that the solid content concentration becomes 0.5% by mass. Outermost layer coating liquid 5 was prepared by adjusting.

(Comparative Example 4)
An inkjet recording material of Comparative Example 4 was obtained in the same manner as in Example 1 except that each ink-receiving layer was coated so that the solid content of the outermost layer after drying was 3 mg/m ² . rice field.

(Comparative Example 5)
An inkjet recording material of Comparative Example 5 was obtained in the same manner as in Example 1 except that each ink-receiving layer was coated so that the solid content of the outermost layer after drying was 30 mg/m ² . rice field.

<Glossiness>
The 75° specular glossiness of both surfaces of each ink jet recording material obtained as described above was measured with a precision gloss meter (GM-26D manufactured by Murakami Color Research Laboratory Co., Ltd.).
○: 75 degree specular glossiness (average value of both surfaces) is 60 or more, and the surface has high glossiness.
x: The 75 degree specular glossiness (average value of both surfaces) is less than 60, and the glossiness of the surface is low.

<Print Density>
After printing an image printed with black ink using a commercial photo printer (Seiko Epson Co., Ltd., SL-D700) on both sides, the print density was measured with a portable spectrophotometer (GretagSpectrolino i1-Pro). was evaluated according to the criteria of The results are shown in Table 1.
Good: The total value of black print density is 2.30 or more.
Δ: Total value of black print density is 2.25 or more and less than 2.30.
x: Total value of black print density is less than 2.25.

<Roller marks due to oil bleeding from the paper feed roller>
After printing with black ink on one side with a commercially available inkjet printer (manufactured by Seiko Epson Co., Ltd., EP-881A), immediately turn it over and print with black ink on the other side. The image printed with black ink was observed at a distance of about 30 cm, and the roller mark was visually evaluated. The results are shown in Table 1.
◯: Slight roller traces due to bleeding of oil are observed.
Δ: Roller traces due to bleeding of oil are observed.
x: Significant roller traces due to bleeding of oil are observed.

The above results demonstrate the effect of the present invention.

Claims (1)

An inkjet recording material having ink-receiving layers mainly containing inorganic fine particles having an average secondary particle size of 500 nm or less on both sides of a non-absorbing support, wherein at least one of the ink-receiving layers has an average primary particle size of 0. An ink jet recording material characterized by having an outermost layer containing 5 to 25 mg/m ² of polyolefin particles of 1 to 0.7 µm.