JP2011011520A - Inkjet recording medium and inkjet recording method - Google Patents

Abstract

An ink jet recording medium in which occurrence of ink bleeding is suppressed is provided.
A gas phase method silica and a porous silica material having hexagonal structure pores having an average pore diameter of 0.8 nm to 20 nm and a volume average particle diameter of 50 nm to 20 μm are provided. An ink receiving layer having a mass ratio of the silica porous body to the total amount of the method silica and the silica porous body of less than 50% by mass is provided on the support.
[Selection figure] None

Description

  The present invention relates to an inkjet recording medium and an inkjet recording method suitable for recording by ejecting ink by an inkjet method.

  In recent years, various methods have been proposed as image recording methods for recording color images. In any case, there are high demands on the quality of recorded matter, such as image quality, texture, and curl after recording.

  For example, as a recording method using an ink jet method, a method using an ink jet recording medium in which a recording layer for receiving ink has a porous structure has been put into practical use. As an example, there is an ink jet recording medium that includes inorganic pigment particles and a water-soluble binder, and a recording layer having a high porosity is provided on a water-resistant support, and has a porous structure, so that the ink can be quickly dried. It has become possible to record photographic-like images such as excellent and high gloss.

  Ink jet recording methods are not only applied in the fields of office printers and home printers, but in recent years are also being applied in commercial printing fields. In this commercial printing field, an ink jet recording that does not have a photo-like surface that completely blocks the penetration of the ink solvent into the support, but has a printing texture, texture, and high-speed recording properties like general-purpose printing paper. Media is requested.

  For example, there is a demand for applications such as commercial printing such as printing images at high speed or many at once, or recording images on both sides. In such applications, not only can the image be recorded at a higher speed when recording ink by ejecting ink, but the quality of the recorded image, such as the glossiness of the recorded image and the fineness of the image, is stable. Is required. However, in situations where high quality or high performance is advancing, the influence of humidity environment or dry state after recording on image quality tends to be negligible when performing double-sided recording or multi-sheet processing or high-speed processing. is there.

  In relation to the above, for example, porous silica having highly regular pores in the mesopore region and dispersed in a submicron order in a solvent is disclosed (for example, see Patent Document 1). As a material that adsorbs moisture, porous silica having hexagonal pores is known (see, for example, Patent Document 2).

JP 2008-137859 A International Publication No. 05/075068 Pamphlet

  However, the conventional ink jet recording medium does not necessarily have an effect of preventing ink bleeding at the time of image recording, and the layer formed simply containing porous silica as described above has a small pore size. Therefore, the effect of preventing bleeding is low. For this reason, the above-described conventional technique has a limit in reducing image bleeding due to color materials such as organic solvents and dyes, and achieving higher image quality.

  The present invention has been made in view of the above, and an ink jet recording medium in which the occurrence of ink bleeding is suppressed (preferably while having high gloss), and a fine image (preferably high gloss) with less ink bleeding. It is an object of the present invention to provide an ink jet recording method capable of recording an image and to achieve the object.

  The composition of the present invention, which is composed of vapor-phase-processed silica as a main component and a porous silica having a pore size of several nanometers in an amount necessary for solvent absorption, is an image when ink is deposited. We have obtained knowledge that it is easy to immobilize most of the dye without bleeding by keeping the pigment component (dye, etc.) that forms the surface near the surface layer and quickly absorbing the solvent component that adversely affects recording performance. Based on that.

Specific means for achieving the above object are as follows.
<1> Gas phase method silica and a porous silica material having hexagonal structure pores having an average pore diameter of 0.8 nm to 20 nm and a volume average particle diameter of 50 nm to 20 μm, An ink jet recording medium having an ink receiving layer on a support, wherein the mass ratio of the porous silica to the total amount of silica and the porous silica is less than 50% by mass.
<2> The porous silica is a specific surface area of 400m ² / g~2000m ² / g, above, wherein the pore volume is 0.1cm ³ /g~3.0cm ³ / g <1> An ink jet recording medium according to the first aspect.
<3> The porous silica has one or more first peaks indicating a diffraction angle corresponding to a d value larger than 2.0 nm in an X-ray diffraction spectrum by CuKα rays, and has a d value smaller than 1.0 nm. The peak intensity of the second peak showing the corresponding diffraction angle is a relative intensity of 200% or less with respect to the peak intensity of the peak showing the maximum intensity among the first peaks, or the second peak is The inkjet recording medium according to <1> or <2>, wherein the inkjet recording medium is not included.
<4> The ink jet recording medium according to any one of <1> to <3>, wherein the silica porous body has an average primary particle diameter of 30 nm to 200 nm.

<5> The inkjet porous medium according to any one of <1> to <4>, wherein the silica porous body has a volume average particle diameter of 50 nm to 500 nm.
<6> In the X-ray diffraction spectrum by CuKα ray, the porous silica has a peak intensity of d ₁₀₀ : d ₁₁₀ : d ₂₀₀ = 100: 5.0 to 20.0: 5.0 to 15.0. The inkjet recording medium according to any one of <1> and <4> to <5>, wherein the ink jet recording medium is expressed by a volume average particle diameter of 50 nm to 500 nm.
<7> The inkjet recording medium according to any one of <1> to <6>, wherein the support is a resin-coated paper in which both sides of a base paper are coated with a resin layer. .
<8> The ink jet recording medium according to any one of <1> to <7>, wherein the ink receiving layer further contains a mordant.
<9> The ink receiving layer has a layer structure composed of two or more layers including a layer containing the porous silica material and a layer containing the vapor phase silica in order from the support side. <1> to the inkjet recording medium according to any one of <8>.

<10> An inkjet recording method for recording an image by applying a dye-based ink containing a dye to the inkjet recording medium according to any one of <1> to <9> above by an inkjet method.
<11> The inkjet recording method according to <10>, wherein a magenta ink containing at least a magenta dye represented by the following general formula (M) is applied as the dye-based ink.
In the following general formula (M), R represents a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group, and X represents Li, Na, or K.

According to the present invention, it is possible to provide an ink jet recording medium in which the occurrence of ink bleeding is suppressed (preferably with high gloss). Also,
According to the present invention, it is possible to provide an ink jet recording method capable of recording a fine image (preferably high gloss) with little ink bleeding.

  Hereinafter, the ink jet recording medium of the present invention and the ink jet recording method using the same will be described in detail.

<Inkjet recording medium>
The ink jet recording medium of the present invention has one or two or more ink receiving layers on a support. As the ink receiving layer, vapor phase method silica and an average pore diameter of 0.8 nm to 20 nm are used. And a porous silica material having a hexagonal structure and a volume average particle diameter of 50 nm to 20 μm, and the mass ratio of the porous silica material to the total amount of the vapor phase method silica and the porous silica material is less than 50% by mass (Hereinafter, also referred to as “ink receiving layer in the present invention”).

-Ink receiving layer-
The ink receiving layer in the present invention includes at least gas phase method silica, a porous silica material having hexagonal pores having an average pore diameter of 0.8 nm to 20 nm, and a volume average particle diameter of 50 nm to 20 μm. Preferably, it contains a water-soluble resin, a mordant (water-soluble metal compound, nitrogen-containing organic cationic polymer, etc.), and if necessary, can be constituted using other components such as a crosslinking agent.

  As the layer structure of the ink receiving layer in the present invention, a layer containing a porous silica (and vapor phase silica and / or water-soluble resin as required) and a layer containing vapor phase silica (in order from the support side) It is also preferable to have a layer structure of two layers or three layers or more in which the ratio of the porous silica material to the total mass of the layer is 20% by mass or less or does not include the porous silica material. By including a porous silica material on the lower layer side, it is easy to penetrate and absorb a solvent that tends to adversely affect recording performance, such as image bleeding, on the lower layer side. A fine image with reduced bleeding can be obtained.

(Silica porous body)
The ink receiving layer in the invention contains at least one kind of porous silica material together with the following vapor phase method silica. The porous silica material refers to a substance mainly composed of silicon oxide having a porous structure with hexagonal pores.

  The pores of the porous silica form a hexagonal structure. That is, in the porous silica, the hexagonal structure can be observed when the X-ray diffraction pattern shows a hexagonal type (preferably 2d-hexagonal type) or when the shape of the pore is directly observed with a transmission electron microscope. Is.

  The X-ray diffraction pattern is measured by a conventional method using, for example, a fully automatic X-ray diffractometer (RINT ULTIMA II, manufactured by Rigaku Corporation) and using CuKα rays as a radiation source. As the transmission electron microscope, for example, JEM-200CX (manufactured by JEOL Ltd.) is used.

The average pore diameter of the pores of the porous silica is 0.8 nm to 20 nm. If the average pore size is less than 0.8 nm, the production suitability is poor, the pore size in the ink receiving layer becomes too small, the solvent adsorbability in the ink is lowered, and ink bleeding tends to occur. On the other hand, when the average pore diameter exceeds 20 nm, the surface roughness is noticeable and the glossiness is lowered. Among these, the average pore diameter is preferably from 0.8 nm to 10 nm, more preferably from 1 nm to 10 nm, and particularly preferably from 1.5 nm to 5 nm, from the viewpoint of ink solvent adsorption.
Further, the pore size distribution is not particularly limited, but from the viewpoint of ink solvent adsorption, it is preferable that the pore size distribution is narrow, and more than 60% of the fine pores show the maximum distribution in the pore size distribution curve. It is more preferable to have a pore size included within a range of ± 40% of the pore size.

The specific surface area of the porous silica is not particularly limited, from the viewpoint of ink solvent ^absorptive, is ^preferably, 600m ² / g~2000m 2 / g be 400m ² / g~2000m 2 / g it is more ^preferable, more preferably 800m ² / g~2000m 2 / ^g, more preferably from 900m ² / g~2000m 2 / g.

Wherein the pore volume of the porous silica material, but from the viewpoint of ink solvent absorptive is ^{preferably 0.1cm 3 /g~3.0cm 3 / g, 0.2cm} 3 / g more preferably ~3.0cm ³ / ^g, more preferably from 0.5cm ³ /g~3.0cm 3 / g.

  The average pore diameter, specific surface area, and pore volume of the porous silica in the present invention can be obtained by a commonly used method. For example, the average pore diameter, specific surface area, and pore volume can be calculated from a nitrogen adsorption isotherm. Specifically, the average pore diameter can be calculated by the BJH method, the BET method, the t method, the DFT method, etc., but in the present invention, it is the average pore diameter calculated by the BJH method. The specific surface area can be calculated by the BET method, the t method, the α method, etc., but in the present invention, it is the specific surface area calculated by the BET method. Further, the pore volume can be calculated by the BJH method, the BET method, the t method, etc., but in the present invention, the pore volume is calculated by the BJH method.

The volume average particle diameter of the porous silica material is in the range of 50 nm to 20 μm. When the volume average particle diameter is less than 50 nm, particles having the average pore diameter as described above are difficult to obtain, the solvent adsorptivity in the ink is lowered and ink bleeding is likely to occur. Roughness is noticeable and glossiness decreases. Among them, the volume average particle diameter is preferably in the range of 50 nm to 10 μm, more preferably in the range of 50 nm to 3 μm, and further in the range of 50 nm to 500 nm, from the viewpoint of enabling the recording of fine image quality by preventing ink bleeding. Is preferred.
Here, the “volume average particle diameter” is the volume average particle diameter of the secondary particles of the porous silica, and is measured by a method usually used by a laser method or a dynamic light scattering method. Specifically, 100 mg of a sample is added to 10 ml of ion exchange and dispersed at 20 KHz, 200 W, 4.4 watt / cm ³ using an ultrasonic generator (UD-200, manufactured by Tommy Seiko Co., Ltd.). The particle size distribution of the obtained dispersion is measured with a laser diffraction / scattering particle size distribution measuring apparatus, and the average particle size is measured as the volume-based average diameter to be measured.

In addition, the average particle diameter of the primary particles of the porous silica is preferably 30 nm to 500 nm, more preferably 30 nm to 200 nm, and more preferably 30 nm to 100 nm from the viewpoint of preventing ink bleeding and improving image quality. More preferably, it is 30 nm-50 nm.
In addition, the average particle diameter of primary particles is measured by measuring the particle diameter of 100 primary particles using a transmission electron microscope and calculating the arithmetic average thereof.

In the X-ray diffraction spectrum by CuKα ray, the porous silica in the present invention has one or more first peaks showing a diffraction angle corresponding to a d value larger than 2.0 nm, and a d value smaller than 1.0 nm. The peak intensity of the second peak showing the corresponding diffraction angle is a relative intensity of 200% or less with respect to the peak intensity of the peak showing the maximum intensity among the first peaks, or has a second peak. Preferably not. By having such a highly regular structure, the adsorption and retention of the ink solvent becomes better.
The first peak preferably exhibits a diffraction angle corresponding to a d value of 2.0 nm to 20.0 nm, more preferably a diffraction angle corresponding to a d value of 2.0 nm to 5.0 nm, More preferably, it shows a diffraction angle corresponding to a d value of 3.0 nm to 5.0 nm.
When the second peak is present, the peak intensity is preferably 100% or less of the maximum intensity indicated by the first peak, more preferably 50% or less, and 30% or less. More preferably, it is more preferably 10% or less.
The X-ray diffraction spectrum and d value are measured by a conventional method using a fully automatic X-ray diffractometer (RINT ULTIMA II, manufactured by Rigaku Corporation).

  Further, in the chlorophyll adsorption test described later, the porous silica is preferably 5 mg or more, more preferably 5 to 100 mg, and more preferably 10 to 100 mg per 100 mg of the porous silica. More preferably, it is 15 mg to 100 mg, more preferably 20 mg to 100 mg. When the chlorophyll adsorption amount is within the above range, the ink solvent adsorption property is further improved.

  The chlorophyll adsorption test in the present invention is performed according to the following procedure. 1 g of porous silica is added to 100 ml of 0.1 mass% sodium hydroxide ethanol solution and stirred at room temperature for 5 minutes. The silica porous body is taken out, washed with ethanol, and dried to obtain an alkali-treated silica porous body. 100 mg of the obtained alkali-treated silica porous material is added to 2 ml of a benzene solution of chlorophyll a (chlorophyll concentration: 20 mM) and shaken at 25 ° C. for 30 minutes. Centrifuge at 7000 rpm for 20 minutes to obtain a supernatant. The concentration of chlorophyll a in the supernatant is measured using a spectrophotometer (U-20000, manufactured by Hitachi High-Technologies), and the adsorption amount of chlorophyll a adsorbed on the porous silica material is calculated from the measured value.

Furthermore, the silica porous body in the present invention has a peak intensity represented by a ratio of d ₁₀₀ : d ₁₁₀ : d ₂₀₀ = 100: 5.0 to 20.0: 5.0 to 15.0 in the X-ray diffraction pattern. Further, those having a volume average particle diameter of 50 nm to 500 nm (preferably 50 nm to 300 nm) are preferable. Here, d ₁₀₀ , d ₁₁₀ , and d ₂₀₀ indicate intervals between the (100) plane, the (110) plane, and the (200) plane, respectively, of the hexagonal structure of the X-ray diffraction pattern. As the regularity of the pores decreases, the peak intensities of d ₁₁₀ and d ₂₀₀ decrease. In particular, the d ₂₀₀ value may be difficult to confirm because the peak itself is unclear, but if the d ₂₀₀ peak clearly appears as a peak and satisfies the above ratio, the regularity of the pores is extremely high. It can be said. In other words, the occurrence of ink bleeding during image recording can be more effectively prevented by having highly regular pores. The volume average particle diameter here is also as described above.

  The regularity of the pores is confirmed by obtaining an X-ray diffraction pattern. Specifically, after heating the sample at 80 to 120 ° C. for 1 hour or longer, the sample is cooled in a desiccator, and the cooled sample is placed on a plate for X-ray diffraction measurement. This sample is made to be a uniform flat surface, and is confirmed by measuring an X-ray diffraction pattern with a fully automatic X-ray diffractometer (RINT ULTIMA II, manufactured by Rigaku Corporation). At this time, if a large amount of moisture remains in the pores, the peak intensity of the d value may be lower than the actual value. Therefore, the measurement of the X-ray diffraction pattern is preferably sufficiently dried in advance.

The ratio of the peak intensities of d ₁₀₀ , d ₁₁₀ , and d ₂₀₀ is determined when the peak intensity of d ₁₀₀ is _{100 in} the volume average particle diameter range from the viewpoint of more effectively preventing the occurrence of ink bleeding. It is more preferable that d ₁₀₀ : d ₁₁₀ : d ₂₀₀ = 100: 8.0 to 20.0: 7.0 to 15.0.

The porous silica includes those added with a metal species during or after synthesis. It is known that when the porous silica is exposed to hot water, steam, or an aqueous alkali metal salt solution, the pore walls of the silica dissolve with time and the specific surface area and pore regularity of the pores are impaired. However, by adding a metal species, it is possible to reduce structural deterioration and enhance durability when exposed to hot water, steam, or an aqueous alkali metal salt solution. In particular, it is effective in the case of a porous silica material having a ratio of peak intensity of d ₁₀₀ , d ₁₁₀ , and d ₂₀₀ and a volume average particle diameter.
As said metal seed | species, 1 type, or 2 or more types chosen from the group of Al, Zr, Ti, Fe, Ga, Sn, V, Cr, and Ru can be contained. A compound containing a metal species may be used. In this case, a compound that is ionized in water, such as sodium aluminate and aluminum nitrate for Al, and zirconium hydrochloride and zirconyl nitrate for Zr are suitable. The metal species may be added at any step during synthesis, or after the synthesis, the porous silica may be added by immersing and drying in an aqueous solution of metal species. The content of the metal species in the ink receiving layer containing the porous silica material is preferably 4% by mass or less from the viewpoint of the pore regularity of the porous silica material.

The method for producing a porous silica material in the present invention is not particularly limited as long as the porous silica material having the above characteristics is obtained. For example, an inorganic raw material is mixed with an organic raw material and reacted to form an organic substance-inorganic compound complex in which an inorganic skeleton is formed around the organic substance as a template. The method of removing is mentioned. Further, for example, (1) a step of dispersing alkoxysilane in a pH 1 to 3 cationic surfactant solution, and (2) silica and a surface activity by adding an alkali source to adjust the pH to 8.5 to 9.5. It can be produced by providing a step in which the complex with the agent forms a gel and a step in which the cationic surfactant is removed from the obtained complex.
Specifically, for example, the production methods described in paragraphs [0015] to [0025] of WO 05/075068 and JP 2008-137859 A can be preferably used.

The inorganic raw material in the present invention is not particularly limited as long as it is a compound containing silicon. Examples of the compound containing silicon include compounds containing silicates such as layered silicates and non-layered silicates, and compounds containing silicon other than silicates.
The layered silicate, kanemite _{(NaHSi 2 O 5 · xH 2} O), sodium disilicate crystal _{(Na 2 Si 2 O 5)} , makatite (NaHSi ₄ O _9), Airaaito _{(NaHSi 8 O 17 · xH 2} O ), Magadiite (Na ₂ HSi ₁₄ O ₂₉ · xH ₂ O), Kenyaite (Na ₂ HSi ₂₀ O ₄₁ · xH ₂ O), and the like. Non-layered silicates include water glass (sodium silicate), glass, amorphous sodium silicate, tetraalkoxysilanes such as tetramethoxysilane (TMOS) and tetraethoxysilane (TEOS), tetramethylammonium (TMA). ) Silicon alkoxides such as silicate and tetraethylorthosilicate. Furthermore, examples of the compound containing silicon other than silicate include silica, silica oxide, and silica-metal composite oxide. These may be used alone or in admixture of two or more.

  Examples of the organic raw material include surfactants. The surfactant may be any of a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant. The surfactants may be used alone or in combination of two or more.

  Examples of the cationic surfactant include primary amine salts, secondary amine salts, tertiary amine salts, and quaternary ammonium salts. Of these, quaternary ammonium salts are preferred. In the production of the porous silica in the present invention, primary to tertiary amine salts and quaternary ammonium salts can be preferably used when the production conditions are in the acidic range. Moreover, when manufacturing conditions are a basic region, a quaternary ammonium salt can be used preferably.

Examples of the quaternary ammonium salt include alkyltrimethylammonium salts having 8 to 22 carbon atoms. Specifically, for example, octyltrimethylammonium chloride, octyltrimethylammonium bromide, octyltrimethylammonium hydroxide, decyltrimethylammonium chloride, decyltrimethylammonium bromide, decyltrimethylammonium hydroxide, dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltrimethylammonium Ammonium hydroxide, tetradecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, tetradecyltrimethylammonium hydroxide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium hydroxide, octadecyl List trimethylammonium chloride, octadecyltrimethylammonium bromide, octadecyltrimethylammonium hydroxide, behenyltrimethylammonium chloride, behenyltrimethylammonium bromide, behenyltrimethylammonium hydroxide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium hydroxide, etc. Can do.
In addition, these quaternary ammonium salts may be used independently or may be used in mixture of 2 or more types.

  Examples of the anionic surfactant include carboxylate, sulfate ester salt, sulfonate salt, and phosphate ester salt. More specifically, soap, higher alcohol sulfate, higher alkyl ether sulfate, sulfated oil, sulfated fatty acid ester, sulfated olefin, alkylbenzenesulfonate, alkylnaphthalenesulfonate, paraffinsulfonate, And higher alcohol phosphoric acid ester salts. These anionic surfactants may be used alone or in combination of two or more.

  Examples of amphoteric surfactants include sodium laurylaminopropionate, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine. These amphoteric surfactants may be used alone or in combination of two or more.

  Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolinic acid derivative, polyoxyethylene polyoxypropylene alkyl ether , Polypropylene glycol, ether derivatives of polyethylene glycol, and nitrogen-containing types such as polyoxyethylene alkylamine. These nonionic surfactants may be used alone or in combination of two or more.

When silicon oxide such as silica (SiO ₂ ) is used as an inorganic raw material, a layered silicate such as kanemite is first formed, a template made of an organic raw material is inserted between the layers, and a layer where no template exists is connected with a silicate molecule or the like. Thus, a silica wall can be formed around the mold, and then the mold can be removed to form pores.
In addition, when water glass or the like is used as an inorganic raw material, silicate monomers are assembled around a mold made of an organic raw material, and this is polymerized to form silica, and then the mold is removed to form pores. it can.

  When a surfactant is used as the organic raw material and pores are formed using the surfactant as a template, micelles can be used as the template. Thereby, for example, by appropriately selecting the alkyl chain length of the surfactant, the diameter of the template can be changed, and the diameter of the pores to be formed can be controlled. Furthermore, in addition to the surfactant, the micelles can be expanded by using a hydrophobic compound (for example, trimethylbenzene, tripropylbenzene, etc.), and pores with larger diameters can be formed. By such a method, a porous silica material in which pores having a desired diameter are formed can be produced.

  In the method for producing a porous silica material, when an inorganic raw material and an organic raw material are mixed, a solvent may be used. Although there is no restriction | limiting in particular as a solvent, For example, water, water-soluble organic solvents, such as alcohol, etc. can be mentioned.

There is no particular limitation on the method of mixing the inorganic raw material and the organic raw material. For example, it is preferable to add water (preferably ion-exchanged water) twice or more in weight ratio to the inorganic raw material, stir at 40 to 80 ° C. for 1 hour or longer, and then add and mix the organic raw material.
There is no restriction | limiting in particular in the mixing ratio of an inorganic raw material and an organic raw material, According to the raw material to be used, it can select suitably. For example, the ratio of inorganic material to organic material (mass ratio) is preferably 0.1: 1 to 5: 1, and more preferably 0.1: 1 to 3: 1.

There are no particular limitations on the reaction conditions of the inorganic raw material and the organic raw material, and they can be appropriately selected according to the raw material used. For example, it is preferable to form a complex of an inorganic substance and an organic substance by stirring at a pH of 11 or more for 1 hour or more and then reacting at a pH of 8.0 to 9.0 for another 1 hour or more.
Moreover, as a method of removing the organic substance from the complex of inorganic substance and organic substance, for example, the complex is filtered, washed with water, dried, and then fired at 400 to 600 ° C., using an organic solvent. Examples thereof include a method for extracting an organic substance. In this invention, it is preferable that it is the method of baking at 400-600 degreeC.

  The silica porous body in the present invention is preferably further metal-crosslinked from the viewpoint of processing stability. Although there is no restriction | limiting in particular as a metal used for bridge | crosslinking, For example, Mn, Co, Ni, Fe, Mg, Al, Cr, Ca, Ge, Ti etc. are mentioned. Among these, Al is preferable from the viewpoint of processing stability. The metal crosslinking can be performed, for example, by dissolving a metal salt in water or the like and then mixing with a porous silica material to perform a crosslinking reaction, and further drying as necessary.

The porous silica obtained as described above is represented, for example, by the following general formula (1).
M _x Al _y Si _z O ₂ General Formula (1)
In the formula, M is a metal element other than Al, and x is 0 or more and 1 or less. y is 0 or more and 1 or less, and z is larger than 0 and 1 or less.
M is a metal element other than Al used for the metal cross-linking of the porous silica, and examples thereof include Mn, Co, Ni, Fe, Mg, Cr, Ca, Ge, and Ti. Further, M may be two or more kinds of metal elements, in which case x means the total value of the two or more kinds of metal elements.

In the present invention, the mass ratio of the porous silica in the ink receiving layer to the total amount of the following vapor phase silica and porous silica is less than 50% by mass. When the mass ratio of the porous silica in the ink receiving layer exceeds 50 mass%, the surface quality is rough and the image quality is deteriorated.
From the viewpoint of more effectively preventing ink bleeding, the mass ratio of the porous silica material to the total amount of the vapor phase silica and the porous silica material is preferably less than 40 mass%, more preferably in the range of 5 to 30 mass%. It is effective.

(Gas phase method silica)
The ink receiving layer in the present invention contains vapor-phase silica as a main component in the entire inorganic particles together with the silica porous body. That is, the content of the gas phase method silica as the main component in the ink receiving layer is 50% by mass or more based on the total amount of the gas phase method silica and the porous silica material.

  Silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to the production method. Among them, the gas phase method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced and vaporized by an arc in an electric furnace and oxidized with air ( The method of obtaining anhydrous silica by the arc method) is the mainstream, and “gas phase method silica” means silica (anhydrous silica fine particles) synthesized by the gas phase method. In the wet method, the mainstream is a method in which active silica is produced by acid decomposition of silicate, and this is appropriately polymerized and coagulated and precipitated to obtain hydrous silica.

Vapor phase silica is different from hydrous silica in terms of the density of silanol groups on the surface, the presence or absence of vacancies, etc., and exhibits different properties, but is suitable for forming a three-dimensional structure with a high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is high at 5 to 8 / nm ² , and the silica fine particles tend to aggregate closely (aggregate). In the case of the method silica, the density of silanol groups on the surface of the fine particles is 2 to 3 / nm ² , so that it is sparse soft aggregation (flocculate), and as a result, it is assumed that the structure has a high porosity. Is done.

  Vapor phase silica has a particularly large specific surface area, so ink absorption and retention efficiency is high, and since the refractive index is low, transparency can be imparted to the receiving layer by dispersing to an appropriate particle size. It is characterized by high color density and good color development. The transparency of the receiving layer is not only for applications that require transparency, such as OHP, but also in terms of obtaining high color density and good color development gloss even when applied to recording media such as photo glossy paper. is important.

  The average primary particle diameter of the vapor phase silica is preferably 30 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and most preferably 3 to 10 nm. Vapor phase silica is easy to adhere to each other by hydrogen bonds with silanol groups, so it can form a structure with a large porosity when the average primary particle size is 30 nm or less, effectively improving ink absorption characteristics. Can be made.

  Further, in the vapor phase method silica, in addition to the porous silica, for example, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, as long as the effect of preventing the occurrence of ink bleeding is not impaired. , Mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, pseudoboehmite, zinc oxide, zinc hydroxide, alumina, aluminum silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide, yttrium oxide Inorganic fine particles such as may be further used in combination.

  The content of the vapor phase silica in the ink receiving layer is preferably 30 to 80% by mass with respect to the total mass of the ink receiving layer.

-Water-soluble resin-
The ink receiving layer in the invention preferably contains at least one water-soluble resin.
Examples of the water-soluble resin include a polyvinyl alcohol resin that is a resin having a hydroxy group as a hydrophilic structural unit [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl. Alcohol, polyvinyl acetal, etc.], cellulose resins (methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.), Chitins, chitosans, starches, resins with ether linkages [polyethylene oxide (PEO), polyp Pyrene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like.
Moreover, the polyacrylic acid salt which has a carboxyl group as a dissociable group, maleic acid resin, alginate, gelatins, etc. can be mentioned.

Among the above, the water-soluble resin is preferably at least one selected from polyvinyl alcohol resins, cellulose resins, resins having an ether bond, resins having a carbamoyl group, resins having a carboxyl group, and gelatins. Polyvinyl alcohol (PVA) resin is preferable.
Examples of polyvinyl alcohol resins include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 3053231. JP-A-63-176173, JP-A-2604367, JP-A-7-276787, JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-158801, JP 2001-213045, JP 2001-328345, JP 8-324105, JP-A-11-348417, JP-A58-181 87, JP-A-10-259213, JP-A-2001-72711, JP-A-2002-103805, JP-A-2000-63427, JP-A-2002-308928, JP-A-2001-205919, JP-A-2002-264489. And the like described in the issue.
Examples of water-soluble resins other than polyvinyl alcohol resins include compounds described in JP-A-11-165461, [0011] to [0012], JP-A-2001-205919, and JP-A-2002-264489. The described compounds are also included.

These water-soluble resins may be used alone or in combination of two or more.
As content of water-soluble resin, 9-40 mass% is preferable with respect to the total solid content mass of an ink receiving layer, and 12-33 mass% is more preferable.

The water-soluble resin and the inorganic fine particles, which mainly constitute the ink receiving layer in the invention, may each be a single material or a mixed system of a plurality of materials.
From the viewpoint of maintaining transparency, the type of water-soluble resin combined with inorganic fine particles, particularly silica fine particles, is important. When the gas phase method silica is used, the water-soluble resin is preferably a polyvinyl alcohol resin, more preferably a polyvinyl alcohol resin having a saponification degree of 70 to 100%, and a saponification degree of 80 to 99.5. % Of polyvinyl alcohol resin is particularly preferable.

  The polyvinyl alcohol-based resin has a hydroxyl group in its structural unit, and since this hydroxyl group and the surface silanol group of the silica fine particle form a hydrogen bond, a three-dimensional network having a secondary particle of the silica fine particle as a network chain unit. It becomes easy to form a structure. By forming this three-dimensional network structure, it is considered that a porous ink receiving layer having a high porosity and sufficient strength is formed. In ink jet recording, the porous ink receiving layer obtained as described above can absorb ink rapidly by a capillary phenomenon, and can form dots with good roundness without ink bleeding.

  In addition, the polyvinyl alcohol resin may be used in combination with the other water-soluble resin. When the other water-soluble resin and the polyvinyl alcohol resin are used in combination, the content of the polyvinyl alcohol resin in the total water-soluble resin is preferably 50% by mass or more, and more preferably 70% by mass or more.

For example, the ink receiving layer is optimized by optimizing the mass ratio [PB ratio (x: y)] between the vapor phase silica and / or the porous silica (x) and the water-soluble resin (y). It is possible to further improve the film structure and film strength.
In the present invention, the PB ratio (x: y) of the ink receiving layer prevents the decrease in film strength and cracking during drying caused by the PB ratio being too large, and the PB ratio is too small. The ratio of 1.5: 1 to 10: 1 is preferable from the viewpoint of preventing the gap from being easily blocked by the resin and preventing the ink absorbency from being lowered due to the decrease in the porosity. The PB ratio is such that the x / y ratio of the upper half of the ink receiving layer is equal to or greater than the x / y ratio of the lower half (the PB ratio is the same in the upper half and the lower half, or the lower half is binder-rich). It is preferable that the PB ratios of the upper half and the lower half are equal.

  Since stress may be applied to the recording medium when passing through the transport system of the ink jet printer, the ink receiving layer needs to have sufficient film strength. Further, when cutting into a sheet shape, the ink receiving layer needs to have sufficient film strength in order to prevent the ink receiving layer from cracking or peeling off. From these points, the PB ratio (x: y) is more preferably 6: 1 or less, and more preferably 2: 1 or more from the viewpoint of ensuring high-speed ink absorbability with an inkjet printer.

-Mordant-
The ink receiving layer in the present invention can contain a mordant. As the mordant, a nitrogen-containing organic cationic polymer or a water-soluble metal compound can be used.
<Nitrogen-containing organic cationic polymer>
The ink receiving layer in the invention preferably contains at least one nitrogen-containing organic cationic polymer from the viewpoint of further suppressing bleeding of the recorded image and from the viewpoint of dispersing silica.

  The nitrogen-containing organic cationic polymer is not particularly limited, but a polymer having a primary to tertiary amino group or a quaternary ammonium base is preferable. The nitrogen-containing organic cationic polymer is a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a monomer having a quaternary ammonium base (nitrogen-containing organic cationic monomer). Conjugated diene systems such as nitrogen-containing organic cation polymers, styrene-butadiene copolymers, methyl methacrylate-butadiene copolymers obtained as copolymers or condensation polymers of the nitrogen-containing organic cation monomers and other monomers Copolymers; Acrylic polymers such as acrylic acid and methacrylic acid ester polymers or copolymers, acrylic acid and methacrylic acid polymers or copolymers; styrene-acrylic acid ester copolymers, styrene-methacrylic acid Styrene-acrylic polymers such as acid ester copolymers; Vinyl resins such as ethylene vinyl acetate copolymers System polymer; the urethane polymer or the like having a urethane bond include a nitrogen-containing organic cation polymers obtained by cationizing modified with a compound containing a cationic group.

Examples of the other monomer that can be copolymerized (or polycondensed) with the nitrogen-containing organic cation monomer include primary to tertiary amino groups and salts thereof, or basic such as quaternary ammonium base. Or the monomer which does not contain a cationic part, does not show interaction with the dye in an inkjet ink, or is substantially small interaction is mentioned. For example, (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylic acid; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate; benzyl (meth) acrylic acid Aralkyl esters of styrene; aromatic vinyls such as styrene, vinyl toluene and α-methyl styrene; vinyl esters such as vinyl acetate, vinyl propionate and vinyl versatate; allyl esters such as allyl acetate; vinylidene chloride, vinyl chloride, etc. A halogenated monomer such as: (c) vinyl cyanide such as (meth) acrylonitrile; and olefins such as ethylene and propylene.
The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety, specifically, for example, methyl (meth) acrylate or ethyl (meth) acrylate. Propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and the like.

  As a monomer constituting the urethane polymer, a polyvalent isocyanate compound having two or more isocyanate groups (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, hydrogenated xylylene diisocyanate) , Hydrogenated 4,4′-diphenylmethane diisocyanate, etc.) and a compound that can react with an isocyanate group to form a urethane bond (for example, glycerin, 1,6-hexanediol, triethanolamine, polypropylene glycol, polyethylene glycol, etc. Polyol compounds; acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, ethylenediamine, propylenediamine, diethylenetriamine, Ethylenediamine, phenylenediamines, amines such as tolylenediamine, hydrazine and the like).

  Furthermore, examples of the compound for introducing a cationic group into a copolymer or condensate having no cationic group include alkyl halides and methylsulfuric acid.

Among the nitrogen-containing organic cationic polymers, from the viewpoint of suppression of bleeding, cationic polyurethanes and cationic polyacrylates described in JP-A No. 2004-167784 are preferable, and cationic polyurethanes are more preferable. As commercial products of cationic polyurethane, for example, “Superflex 650”, “F-8564D”, “F-8570D” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Neofix IJ-” manufactured by Nikka Chemical Co., Ltd. 150 "and the like.
Further, from the viewpoint of particle dispersion, polydiallyldimethylammonium chloride and polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride derivatives are preferable, and polydiallyldimethylammonium chloride is more preferable. Examples of commercially available products include “Charol DC902P” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

<Water-soluble metal compound>
The ink receiving layer in the invention preferably contains at least one water-soluble metal compound.
Examples of the water-soluble metal compound include water-soluble salts of metals selected from calcium, magnesium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, tungsten, and molybdenum. For example, magnesium salts include magnesium acetate, magnesium oxalate, magnesium sulfate, magnesium chloride hexahydrate, and magnesium citrate nonahydrate. Of these, magnesium chloride hexahydrate is preferred.
The “water-soluble” of the water-soluble metal compound means that 1% by mass or more dissolves in 20 ° C. water.

  Among the water-soluble metal compounds, a trivalent or higher valent metal compound is preferable, an aluminum compound or a compound containing a Group 4A metal (for example, zirconium or titanium) in the periodic table is preferable, and an aluminum compound is more preferable. Particularly preferred is a water-soluble aluminum compound.

Examples of the water-soluble aluminum compound include aluminum chloride or a hydrate thereof (eg, aluminum chloride hexahydrate), aluminum sulfate or a hydrate thereof, ammonium alum, aluminum sulfite, aluminum thiosulfate, aluminum nitrate nine water Japanese hydrates, aluminum acetate, aluminum lactate, basic aluminum thioglycolate and the like are known. Furthermore, basic polyaluminum hydroxide compounds (hereinafter also referred to as “basic polyaluminum chloride” and “polyaluminum chloride”), which are inorganic aluminum-containing cationic polymers, are known and preferably used. The basic polyaluminum hydroxide compound is represented by the following formula 1, formula 2 or formula 3, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ ] ⁵⁺ , [Al ₂₁ (OH) ₆₀ ] ³⁺ , and the like, which are water-soluble polyaluminum hydroxides that stably contain basic and high-molecular polynuclear condensed ions.
[Al ₂ (OH) _n Cl _6-n ] _m (Formula 1)
[Al (OH) ₃ ] _n AlCl ₃ (Formula 2)
Al _n (OH) _m Cl _{(3 nm)} [0 <m <3n] (Formula 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 named -25 by Daiming Chemical Co., Ltd., and is also marketed by other manufacturers for the same purpose, and various grades are easily available.

  As the compound containing the Group 4A metal of the periodic table, a water-soluble compound containing titanium or zirconium is more preferable. Examples of the water-soluble metal compound containing titanium include titanium chloride, titanium sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, and titanium lactate. Examples of water-soluble metal compounds containing zirconium include zirconium acetate, zirconyl acetate, zirconium chloride, hydroxy zirconium chloride, zirconium nitrate, zirconyl nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium lactate, zirconyl lactate, zirconium carbonate / ammonium carbonate, Zirconium / potassium, zirconyl / ammonium carbonate, zirconyl / potassium carbonate, zirconium sulfate, zirconium fluoride, zirconyl sulfate, zirconyl fluoride, and the like.

  The content of the water-soluble metal compound (preferably a water-soluble aluminum compound) in the ink receiving layer is 0.1 with respect to the total amount of the vapor phase silica and the porous silica material in terms of image density and water resistance. 10 mass% is preferable, and 0.5-8 mass% is more preferable.

-Sulfur compounds-
The ink receiving layer in the invention can contain a sulfur compound from the viewpoint of further improving the ozone resistance. As the sulfur compound, one or more selected from thioether compounds, thiourea compounds, disulfide compounds, sulfinic acid compounds, thiocyanic acid compounds, sulfur-containing heterocyclic compounds, and sulfoxide compounds are suitable. Can be used. Of the sulfur compounds, thioether compounds or sulfoxide compounds are preferred.
Specific examples of the sulfur-based compound include compounds described in paragraph numbers [0024] to [0088] of JP-A-2008-246989.

For example, when a thioether-based compound is contained, the preservability of the image area (fading due to a trace gas such as ozone or nitrogen oxide in the air) is further improved. As the thioether compound, a compound represented by the following general formula (A) is preferably used.
R < ₁ >-(S-R < ₃ >) _m- S-R < ₂ > ... General formula (A)
In the general formula (A), R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group, or an aromatic group, and R ₁ and R ₂ may be the same or different, and combine to form a ring. May be. In addition, at least one of R ₁ and R ₂ is an alkyl group or an aromatic group substituted with a hydrophilic group such as an amino group, an amide group, an ammonium group, a hydroxy group, a sulfo group, a carboxy group, an aminocarbonyl group, or an aminosulfonyl group. It is a group. R ₃ represents an alkylene group having an oxygen atom. m represents a positive number of 0 to 10, and when m is 1 or more, at least one sulfur atom bonded to R ₃ may be a sulfonyl group.

  Examples of the thioether compounds include 3-thia-1,5-heptanediol, 4-thia-1,7-pentanediol, 3,6-dithia-1,8-octanediol, 3,6,9- Examples include trithia-1,11-undecanediol, 3,9-dithia-6-oxa-1,11-undecanediol, methylenebis (thioglycolic acid), bis [2- (2-hydroxyethylthio) ethyl] sulfone, and the like. It is done.

  The content of the sulfur-based compound in the ink receiving layer is preferably in the range of 0.5 to 50% by mass, more preferably in the range of 1 to 40% by mass with respect to the total solid content of the ink receiving layer.

-Crosslinking agent-
The ink receiving layer in the invention preferably contains at least one crosslinking agent from the viewpoint of crosslinking the water-soluble resin. In the present invention, the ink receiving layer is preferably a porous layer cured by a crosslinking reaction between a crosslinking agent and a water-soluble resin.

Boron compounds are preferred for crosslinking the water-soluble resin, particularly polyvinyl alcohol.
Examples of the boron compound include borax, boric acid, borate (for example, orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , diboric acid. Salt (eg, Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborate (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (eg, Na ₂ B ₄ O ₇ · 10H ₂ O), pentaborate (for example, KB ₅ O ₈ · 4H ₂ O, Ca ₂ B ₆ O ₁₁ · 7H ₂ O, CsB ₅ O ₅ ), etc. Borax, boric acid and borates are preferred, and boric acid is particularly preferred in that a crosslinking reaction can be promptly caused.

The following compounds other than the boron compound can also be used as a crosslinking agent for the water-soluble resin.
For example, aldehyde compounds such as formaldehyde, glyoxal, and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5- Active halogen compounds such as triazine and 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide) ), Active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; melamine resins (for example, methylolmelamine, alkylated methylolmelamine) Epoxy resin; 1,6- Isocyanate compounds such as hexamethylene diisocyanate; Aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983611; Carboximide compounds described in US Pat. No. 3,100,704; Epoxys such as glycerol triglycidyl ether Compounds; ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; dioxane such as 2,3-dihydroxydioxane Compounds: titanium lactate, aluminum sulfate, chromium alum, potash alum, metal-containing compounds such as zirconyl acetate and chromium acetate, polyamine compounds such as tetraethylenepentamine, hydrazide compounds such as adipic acid dihydrazide, oxazo A low molecule or polymer containing two or more phosphorus groups can be used.

A crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type.
1-50 mass% is preferable with respect to water-soluble resin, and, as for content of a crosslinking agent, 5-40 mass% is more preferable.

-Other ingredients-
The ink receiving layer in the invention may contain other components such as a mordant other than the nitrogen-containing organic cationic polymer and the water-soluble polyvalent metal salt, and various surfactants. As other components, the components described in paragraph numbers [0088] to [0117] of JP-A-2005-14593 and the components described in paragraph numbers [0138] to [0155] of JP-A-2006-321176 Etc. can be appropriately selected and used.

-Support-
As the support in the present invention, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used. In order to make use of the transparency of the ink receiving layer, it is preferable to use a transparent support or a highly glossy opaque support. Further, a read-only optical disk such as a CD-ROM or DVD-ROM, a write-once optical disk such as a CD-R or DVD-R, or a rewritable optical disk may be used as a support to provide an ink receiving layer on the label surface side. it can.

As a material that can be used for the transparent support, a material that is transparent and can withstand radiant heat when used in an OHP or a backlight display is preferable. Examples of the material include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
Although there is no restriction | limiting in particular as thickness of the said transparent support body, 50-200 micrometers is preferable at the point which is easy to handle.

As the highly glossy opaque support, one having a glossiness of 40% or more on the surface on which the ink receiving layer is provided is preferable. The glossiness is a value determined according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard). Specifically, for example, high gloss paper support such as art paper, coated paper, cast coated paper, baryta paper used for silver salt photographic support, polyesters such as polyethylene terephthalate (PET), Cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide are made opaque by adding white pigments (surface calendering is applied) A high-gloss film; or a polyolefin coating layer containing or not containing a white pigment on the surface of the above-mentioned various paper supports, the above-mentioned transparent support, or a high-gloss film containing a white pigment or the like. A provided support (eg both sides of the base paper Resin-coated paper coated with a resin layer of the olefin), and the like.
A white pigment-containing foamed polyester film (for example, foamed PET containing polyolefin fine particles and forming voids by stretching) can also be suitably exemplified. Furthermore, resin-coated paper used for silver salt photographic printing paper is also suitable.

  Although there is no restriction | limiting in particular also about the thickness of the said opaque support body, 50-300 micrometers is preferable at the point of handleability.

  The surface of the support may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment or the like in order to improve wettability and adhesion.

Next, the base paper used for the register coat paper will be described in detail.
As the base paper, wood pulp is used as a main raw material, and paper is made using synthetic pulp such as polypropylene or synthetic fiber such as nylon or polyester in addition to wood pulp as necessary. As the above-mentioned wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, NUKP can be used, but more LBKP, NBSP, LBSP, NDP, LDP with more short fibers are used. preferable.
However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.
The pulp is preferably a chemical pulp (sulfate pulp or sulfite pulp) with few impurities, and a pulp having a whiteness improved by bleaching is also useful.

  In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancing agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, polyethylene glycols A water retaining agent such as a dispersant, a softening agent such as a quaternary ammonium, and the like can be appropriately added.

The freeness of the pulp used for papermaking is preferably 200 to 500 ml as defined by CSF, and the fiber length after beating is a 24 mesh residual mass and 42 mesh residual as defined in JIS P-8207. The sum of 30% and 70% by mass is preferable. In addition, it is preferable that the mass% of 4 mesh remainder is 20 mass% or less.
The basis weight of the base paper is preferably 30 to 250 g, and particularly preferably 50 to 200 g. The thickness of the base paper is preferably 40 to 250 μm. The base paper can be given a high smoothness by calendering at the paper making stage or after paper making. The density of the base paper is generally 0.7 to 1.2 g / m ² (JIS P-8118).
The stiffness of the base paper is preferably 20 to 200 g under the conditions specified in JIS P-8143.
A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, a sizing agent similar to the size that can be added to the base paper can be used.
The pH of the base paper is preferably 5 to 9 when measured by a hot water extraction method defined in JIS P-8113.

  Examples of the polyolefin coating layer that covers the front and back surfaces of the base paper include polyethylene. The polyethylene is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but other LLDPE, polypropylene and the like can also be used in part.

  In particular, the polyethylene layer on the side on which the ink receiving layer is formed is obtained by adding rutile or anatase type titanium oxide, fluorescent whitening agent, ultramarine to polyethylene, as is widely done in photographic paper. Those having improved whiteness and hue are preferred. Here, as a titanium oxide content, about 3-20 mass% is preferable with respect to polyethylene, and 4-13 mass% is more preferable. Although the thickness of a polyethylene layer does not have limitation in particular, 10-50 micrometers is suitable for both front and back layers. Further, an undercoat layer can be provided on the polyethylene layer in order to provide adhesion to the ink receiving layer. As the undercoat layer, aqueous polyester, gelatin and PVA are preferable. Moreover, as thickness of this undercoat layer, 0.01-5 micrometers is preferable.

  Polyethylene-coated paper can be used as glossy paper, or when it is melt-extruded onto the surface of the base paper and coated, the matte surface or silky surface that can be obtained with ordinary photographic printing paper by so-called molding Can also be used.

  A back coat layer can be provided on the support, and the components that can be added to the back coat layer include white pigments, aqueous binders, and other components (eg, antifoaming agents, antifoaming agents, dyes, fluorescent whitening). Agents, preservatives, water-proofing agents, etc.).

-Others-
The ink jet recording medium in the invention may further have an ink solvent absorption layer, an intermediate layer, a protective layer and the like in addition to the ink receiving layer. In addition, an undercoat layer may be provided on the support for the purpose of enhancing the adhesion between the ink receiving layer and the support and appropriately adjusting the electric resistance value.

~ Formation of ink receiving layer ~
The ink receiving layer can be suitably formed by the following first and second modes.
The first form of forming the ink receiving layer includes a step of applying a first liquid containing at least gas phase method silica and porous silica on the substrate to form a coating layer, and the coating layer (1) at the same time as the application of the first liquid, or (2) during the drying of the coating layer formed by applying the first liquid and before the coating layer exhibits reduced-rate drying. In such a case, there is provided a step of applying a second liquid containing a basic compound and crosslinking and curing the coating layer to form an ink receiving layer in which the coating layer is crosslinked and cured.

  Further, the second form of forming the ink receiving layer is formed by applying a first liquid containing vapor phase silica and porous silica on the substrate to form a coating layer on the substrate. The ink receiving layer is formed by providing a step of cooling the applied layer so as to decrease by 5 ° C. or more with respect to the temperature of the first liquid at the time of application and a step of drying the cooled application layer. is there.

<Coating layer formation process>
In the first and second embodiments, a coating layer is formed by applying a first liquid containing vapor phase silica and a porous silica material on a substrate (hereinafter referred to as “coating layer forming step”). Also called). In the case of forming a two-layer ink-receiving layer, the coating layer forming step includes, as the first liquid, a silica porous material and, if necessary, gas phase method silica and / or a water-soluble resin on the support. 1 coating liquid and a second coating liquid containing vapor phase silica (preferably, the ratio of the porous silica material to the total mass of the coating liquid is 20% by mass or less or does not include the porous silica material). An application layer may be formed by applying multiple layers in order from the body side.
Application | coating of a 1st liquid can be performed using well-known coating apparatuses, such as an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, a bar coater, for example. The wet coating amount of the first solution is preferably ^{50~200ml / m 2, 75~150ml / m} 2 is more preferable. Moreover, as a solid content application quantity of 1st liquid, 5-25 g / m < ² > is preferable and 10-18 g / m < ² > is more preferable.

  The first liquid can contain other components such as a water-soluble resin, a crosslinking agent, a mordant, a dispersant, and a surfactant. Moreover, in application | coating of a 1st liquid, it is also preferable to apply, after carrying out in-line mixing of the liquid containing water-soluble polyvalent metal salt (preferably basic polyaluminum chloride compound) as stated above.

  The first liquid is preferably acidic, and the pH is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 4.0 or less. When the pH of the first liquid is 5.0 or less, for example, the crosslinking reaction of the water-soluble resin by the crosslinking agent (particularly the boron compound) in the first liquid can be more sufficiently suppressed.

The first liquid containing vapor-phase process silica can be prepared, for example, as follows. That is,
Vapor phase silica fine particles, silica porous material and dispersant are added to water (for example, gas phase silica and silica porous material in water are 10 to 20% by mass), and a high-speed rotating wet colloid mill (for example, M.M. After using, for example, 10000 rpm (preferably 5000 to 20000 rpm) and rotating for 20 minutes (preferably 10 to 30 minutes) using, for example, “CLEAMIX” manufactured by Technic Co., Ltd., a crosslinking agent (For example, boric acid) and an aqueous solution of polyvinyl alcohol (PVA) (for example, PVA having a mass of about 1/3 of the above-mentioned gas phase method silica) are added, and further a water-soluble polyvalent metal salt (for example, basic polyvalent metal). It can be prepared by adding an aluminum hydroxide compound) and dispersing under the same rotational conditions as described above. The water-soluble polyvalent metal salt may be added by in-line mixing immediately before coating.
Moreover, a liquid-liquid collision type disperser (for example, an optimizer manufactured by Sugino Machine Co., Ltd.) can also be used for the dispersion.
The obtained coating liquid is in a uniform sol state, and a porous ink receiving layer having a three-dimensional network structure can be formed by applying the coating liquid onto a substrate by the following coating method and drying it.

In addition, preparation of an aqueous dispersion composed of vapor phase silica and a dispersant may be carried out by preparing in advance an aqueous dispersion of vapor phase silica and porous silica and adding the aqueous dispersion to an aqueous dispersion solution. Then, the aqueous dispersant may be added to the vapor phase silica and the aqueous silica dispersion, or may be mixed at the same time. Further, the vapor phase silica or porous silica may be added to the aqueous dispersant as described above in the form of powder, not as an aqueous dispersion.
An aqueous dispersion can be obtained by mixing the gas phase method silica, the porous silica material, and the dispersant, and then finely pulverizing the mixture using a disperser. Dispersers used for obtaining the aqueous dispersion include various types of conventionally known high-speed rotating dispersers, medium stirring dispersers (ball mill, sand mill, etc.), ultrasonic dispersers, colloid mill dispersers, high pressure dispersers and the like. Although a disperser can be used, a stirrer-type disperser, a colloid mill disperser, or a high-pressure disperser is preferable from the viewpoint of efficiently dispersing the formed fine particles.

  As the solvent, water, an organic solvent, or a mixed solvent thereof can be used. Examples of the organic solvent that can be used for this coating include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. It is done.

  In addition, a chaotic polymer can be used as the dispersant. Examples of the chaotic polymer include mordant examples described in paragraph numbers 0138 to 0148 of JP-A No. 2006-321176. It is also preferable to use a silane coupling agent as the dispersant. The amount of the dispersant added to the vapor phase silica is preferably 0.1% by mass to 30% by mass, and more preferably 1% by mass to 10% by mass.

<Crosslinking curing process>
In the first embodiment, for the coating layer formed in the coating layer forming step,
(1) At the same time as the first liquid is applied, or (2) during the drying of the coating layer formed by applying the first liquid, before the coating layer exhibits reduced-rate drying,
In any of the cases, there is a step of applying a second liquid containing a basic compound and crosslinking and curing the coating layer (hereinafter also referred to as “crosslinking and curing step”).

  As a method of applying the second liquid at the same time as “(1) Applying the first liquid”, a mode in which the first liquid and the second liquid are simultaneously applied in order from the substrate side is preferable. The simultaneous multilayer coating can be performed using a known coating apparatus such as an extrusion die coater or a curtain flow coater.

The method of applying the second liquid before “(2) during the drying of the coating layer formed by applying the first liquid and before the coating layer exhibits reduced-rate drying” is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-2005. The so-called Wet-On-Wet method (WOW method) described in paragraph Nos. 0016 to 0037 of Japanese Patent No. 14593 is preferable. In the present invention, after the first liquid is applied to the base material to form the coating layer, (i) the coating is performed during the drying of the formed coating layer and before the coating layer exhibits reduced-rate drying. A method of applying the second liquid on the layer, (ii) a method of spraying the second liquid on the coating layer by spraying, or (iii) immersing the substrate on which the coating layer is formed in the second liquid It can be done by the method to do.
In the above (i), the application method for applying the second liquid is, for example, curtain flow coater, extrusion die coater, air doctor coater, bread coater, rod coater, knife coater, squeeze coater, reverse roll coater, bar coater. A known coating method such as the above can be used. However, it is preferable to use a method in which the coater does not directly contact an already formed coating layer, such as an extrusion die coater, a curtain flow coater, a bar coater or the like.

  The term “before the coating layer comes to show reduced-rate drying” usually refers to a process for several minutes immediately after the application of the coating liquid for forming the ink receiving layer (first liquid). This shows the phenomenon of “constant rate drying” in which the content of the solvent (dispersion medium) in the applied layer decreases in proportion to time. About the time which shows this "constant rate drying", it describes in chemical engineering handbook (pages 707-712, Maruzen Co., Ltd. issue, October 25, 1980), for example.

  As a condition for drying until the coating layer exhibits reduced-rate drying, it is generally performed at 40 to 180 ° C. for 0.5 to 10 minutes (preferably 0.5 to 5 minutes). The drying time varies depending on the coating amount, but usually the above range is appropriate.

Next, the said 2nd liquid in a bridge | crosslinking hardening process is demonstrated.
The second liquid contains at least one basic compound. Examples of basic compounds include ammonium salts of weak acids, alkali metal salts of weak acids (eg, lithium carbonate, sodium carbonate, potassium carbonate, lithium acetate, sodium acetate, potassium acetate, etc.), alkaline earth metal salts of weak acids (eg, , Magnesium carbonate, barium carbonate, magnesium acetate, barium acetate, etc.), hydroxyammonium, primary to tertiary amines (eg, triethylamine, tripropylamine, tributylamine, trihexylamine, dibutylamine, butylamine, etc.), primary to tertiary Aniline (eg, diethylaniline, dibutylaniline, ethylaniline, aniline, etc.), optionally substituted pyridine (eg, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 4- (2-hydroxy) Ethyl) -ami Pyridine, and the like), and the like. In addition to the basic compound, other basic substances and / or salts thereof may be used in combination with the basic compound. Examples of other basic substances include ammonia, primary amines such as ethylamine and polyallylamine, secondary amines such as dimethylamine, tertiary amines such as N-ethyl-N-methylbutylamine, and alkali metals. And alkaline earth metal hydroxides.

  Of these, ammonium salts of weak acids are particularly preferred. The weak acid is an inorganic acid or an organic acid described in Chemical Handbook Fundamentals II (Maruzen Co., Ltd.) or the like and has an pKa of 2 or more. Examples of the weak acid ammonium salt include ammonium carbonate, ammonium hydrogen carbonate, ammonium borate, ammonium acetate, and ammonium carbamate. However, it is not limited to these. Among these, ammonium carbonate, ammonium hydrogen carbonate, and ammonium carbamate are preferable, and are effective in that ink bleeding can be reduced without remaining in the layer after drying. In addition, a basic compound can use 2 or more types together.

  As content in the 2nd liquid of the said basic compound (especially ammonium salt of weak acid), 0.5-10 mass% is preferable with respect to the total mass (a solvent is included) of 2nd liquid, More preferably, 1 ˜5 mass%. When the content of the basic compound (particularly the ammonium salt of the weak acid) is particularly in the above range, a sufficient degree of curing can be obtained, and the ammonia concentration becomes too high without impairing the working environment.

A mode in which the second liquid contains at least one metal compound is preferable.
As the metal compound contained in the second liquid, those that are stable under basicity can be used without limitation, and any of the water-soluble polyvalent metal salts, metal complex compounds, inorganic oligomers, or inorganic polymers described above can be used. There may be. For example, zirconium compounds and the compounds listed as inorganic mordants in paragraph numbers 0100 to 0101 in JP-A-2005-14593 are suitable. Examples of the metal complex compound include metal complexes described in “Chemical Review No. 32 (1981)” edited by the Chemical Society of Japan, “Coordination Chemistry Review”, Vol. 84, pages 85-277. (1988) and JP-A-2-182701, transition metal complexes containing a transition metal such as ruthenium can be used.

  Among the above, zirconium compounds and zinc compounds are preferable, and zirconium compounds are particularly preferable. Zirconium compounds include, for example, ammonium zirconium carbonate, ammonium zirconium nitrate, potassium zirconium carbonate, ammonium zirconium citrate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconium oxychloride, and zirconium zirconium hydroxy chloride. Zirconium ammonium is preferred. In the second liquid, two or more metal compounds (preferably containing a zirconium compound) may be used in combination.

  As content in the 2nd liquid of the said metal compound (especially zirconium compound), 0.05-5 mass% is preferable with respect to the total mass (a solvent is included) of a 2nd liquid, More preferably, it is 0.1-0.1%. 2% by mass. By setting the content of the metal compound (especially zirconium compound) in the above range, the coating layer can be sufficiently hardened, and the mordanting ability is lowered and sufficient print density cannot be obtained or beading occurs. The concentration of the basic compound such as ammonia is not too high, and the working environment is not deteriorated. Two or more metal compounds can be used in combination, and when other mordant components to be described later are used in combination with a metal compound other than the metal compound, the total amount is within the above range and does not impair the effects of the present invention. It can be contained in a range.

  From the viewpoint of image density and ozone resistance, the second liquid preferably contains a magnesium salt as a metal compound. As the magnesium salt, magnesium chloride is particularly preferred. In this case, the addition amount of the magnesium salt is preferably 0.1 to 1% by mass, and more preferably 0.15 to 0.5% by mass with respect to the total mass of the second liquid.

The second liquid may contain a crosslinking agent and other mordant components as necessary.
The second liquid can be used as an alkaline solution to promote hardening of the coating layer, and is preferably adjusted to pH 7.1 or higher, more preferably pH 8.0 or higher, particularly preferably pH 9.0 or higher. is there. When the pH is 7.1 or more, the crosslinking reaction of the water-soluble resin that may be contained in the first liquid can be further promoted, and bronzing and cracking of the ink receiving layer can be more effectively suppressed.

  The second liquid is, for example, ion-exchanged water, a metal compound (for example, zirconia compound; for example, 1 to 5%) and a basic compound (for example, ammonium carbonate; for example, 1 to 5%), and paraffin as necessary. It can be prepared by adding toluenesulfonic acid (for example, 0.5 to 3%) and stirring sufficiently. In addition, all "%" of each composition means solid content mass%. Moreover, water, an organic solvent, or these mixed solvents can be used for the solvent used for preparation of a 2nd liquid. Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, i-propanol and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate and toluene.

  On the other hand, the second liquid preferably has a small content of inorganic particles such as silica particles, and the content of the inorganic particles is preferably 50% by mass or less based on the total solid content of the second liquid. It is desirable not to include inorganic particles.

<Cooling and drying process>
In the second embodiment, the step of cooling the coating layer formed in the coating layer forming step so as to decrease by 5 ° C. or more with respect to the temperature of the first liquid at the time of coating (hereinafter referred to as “cooling step”). And a step of drying the cooled coating layer (hereinafter also referred to as “drying step”).

As a method for cooling the coating layer in the cooling step, a method of cooling the substrate on which the coating layer is formed in a cooling zone maintained at 0 to 10 ° C. for 5 to 30 seconds is preferable. In a cooling process, it is preferable to cool so that it may fall 0-10 degreeC, and it is more preferable to cool so that it may fall 0-5 degreeC or more. Here, the temperature of the coating layer is measured by measuring the temperature of the film surface.
Moreover, drying in a drying process can be performed by, for example, applying drying air. The temperature of the drying air at this time is preferably 30 to 80 ° C.

<Inkjet recording method>
The ink jet recording method of the present invention records an image by applying at least a magenta ink containing a magenta dye represented by the following general formula (M) to the ink jet recording medium of the present invention described above by the ink jet method. . The ink jet recording method of the present invention further includes inks other than magenta ink, such as yellow (Y), cyan (C), black (K), red (R), green (G), and blue (B). The inks of the hues may be used in appropriate combinations.

In the image recording by the ink jet method, a colored image is recorded by ejecting ink by supplying energy. As a preferred inkjet method, the method described in paragraph Nos. 0093 to 0105 of JP-A No. 2003-306623 can be applied.
The inkjet system for recording an image on the inkjet recording medium of the present invention is not particularly limited, and a known system, for example, a charge control system for discharging ink using electrostatic attraction, a vibration pressure of a piezoelectric element. Drop-on-demand method using pressure (pressure pulse method), acoustic ink-jet method that converts electrical signals into acoustic beams, irradiates the ink, and ejects ink using radiation pressure, and heats the ink to form bubbles Further, a thermal ink jet method using the generated pressure can be used. The ink jet recording method includes a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality using a plurality of inks having substantially the same hue and different concentrations, and a colorless and transparent type. A method using ink is included.

  The magenta ink contains a magenta dye represented by the following general formula (M). The magenta ink generally contains an aqueous medium such as water or a mixed solvent of water and an organic solvent compatible with the water, and if necessary, further known additives (for example, boron compounds, drying inhibitors (wetting) Agent), anti-fading agent, emulsification stabilizer, penetration enhancer, ultraviolet absorber, antiseptic, antifungal agent, pH adjuster, surface tension adjuster, antifoaming agent, viscosity adjuster, dispersant, dispersion stabilizer, It can be prepared using a rust inhibitor, a chelating agent, or the like.

[Magenta dye]
The magenta dye represented by the following general formula (M) has a relatively large molecular weight, and when recorded on the ink receiving layer containing the porous silica as described above, the solvent and the dye are easily separated, and the ink bleeding Excellent generation prevention effect. Further, this magenta dye is excellent in ozone resistance and light resistance.

General formula (M):

In the general formula (M), R represents a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group, and X represents Li, Na, or K. R may be all the same or different. All Xs may be the same or different.
Examples include the following compounds, but the present invention is not limited thereto.

  In the magenta ink, in addition to the dye represented by the general formula (M), for example, an aryl or heteryl azo dye having phenols, naphthols, anilines as a coupler component; for example, pyrazolones, pyrazolotriazoles as a coupler component Azomethine dyes having, for example, arylidene dyes, styryl dyes, merocyanine dyes, cyanine dyes, oxonol dyes and other methine dyes; diphenylmethane dyes, triphenylmethane dyes, xanthene dyes and other carbonium dyes; A quinone dye; for example, a condensed polycyclic dye of a dioxazine dye can be appropriately used in combination. Specifically, heterocyclic azo dyes are suitable. International Patent Publication No. 2002/83795 (pages 35 to 55), 2002/83662 (pages 27 to 42), JP-A-2004-149560 Publications (paragraph numbers “0046” to “0059”), 2004-149561 publication (paragraph numbers “0047” to “0060”), and 2007-70573 publication (paragraph numbers “0073” to “0082”) The thing which was done is mentioned.

A pigment may be used in combination. There is no restriction | limiting in particular as a pigment, According to the objective, it can select suitably, For example, any of an organic pigment and an inorganic pigment may be sufficient.
Examples of organic pigments include azo pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments and polycyclic pigments are more preferable. Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black. Among these, carbon black is particularly preferable. In addition, as said carbon black, what was manufactured by well-known methods, such as a contact method, a furnace method, and a thermal method, is mentioned, for example.

  In addition, when using cyan ink, yellow ink, and black ink (and ink of other hues such as R, G, and B as necessary) together with magenta ink, cyan dye, yellow dye, and black dye are as follows: Dyes are preferred. In addition, each ink generally contains an aqueous medium such as water or a mixed solvent of water and an organic solvent compatible with the water, and other dyes or pigments other than those described below may be used in combination. Depending on the case, it can be further prepared using the known additives.

[Cyan dye]
Examples of cyan dyes include aryl or heteryl azo dyes having, for example, phenols, naphthols, anilines, etc. as coupler components; Polymethine dyes such as dyes, oxonol dyes, merocyanine dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes; phthalocyanine dyes; anthraquinone dyes; indigo / thioindigo dyes. It is not limited. Specifically, associative phthalocyanine dyes are preferable, International Patent Publication Nos. 2002/60994, 2003/811, 2003/62324, JP 2003-213167, 2004- No. 75986, No. 2004-323605, No. 2004-315758, No. 2004-315807, No. 2005-179469, No. 2007-70573 (paragraph numbers “0083” to “0090”) What has been described.
Among them, the cyan dye has a relatively large molecular weight, and when recorded on the ink receiving layer containing the porous silica as described above, the solvent and the dye are easily separated from each other, and is excellent in the effect of preventing the occurrence of ink bleeding. The following structural formula is preferred. This cyan dye is excellent in ozone resistance and light resistance.

Ｘ＝ＳＯ_２（ＣＨ_２）_３ＳＯ_３Ｌｉ（全てのＸの３／４）
ＳＯ_２（ＣＨ_２）_３ＳＯ_２ＮＨＣＨ_２ＣＨ（ＣＨ_３）ＯＨ（全てのＸの１／４）

X = SO ₂ (CH ₂ ) ₃ SO ₃ Li (3/4 of all X)
_{SO 2 (CH 2) 3 SO} 2 NHCH 2 CH (CH 3) OH (1/4 of all X)

Ｘ＝ＳＯ_２（ＣＨ_２）_３ＳＯ_３Ｌｉ（全てのＸの２／４）
ＳＯ_２（ＣＨ_２）_３ＳＯ_２ＮＨＣＨ_２ＣＨ（ＣＨ_３）ＯＨ（全てのＸの２／４）

X = SO ₂ (CH ₂ ) ₃ SO ₃ Li (2/4 of all X)
_{SO 2 (CH 2) 3 SO} 2 NHCH 2 CH (CH 3) OH (2/4 of all X)

[Yellow dye]
Examples of the yellow dye include International Patent Publication No. 2005/075573, JP-A-2004-83903 (paragraph numbers “0024” to “0062”), and 2003-277661 (paragraph numbers “0021” to “0050”). No. 2003-277262 (paragraph numbers “0042” to “0047”), No. 2003-128953 (paragraph numbers “0025” to “0076”), No. 2003-41160 (paragraph number “0028”). ”To“ 0064 ”), those described in US 2003/0213405 (paragraph number“ 0108 ”), and C.I. I. Direct yellow 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44, 50, 53, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110, 130, 132, 142, 144, 161, 163, C.I. I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76, 79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199, 218, 219, 222, 227, C.I. I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27, 29, 35, 37, 41, 42, C.I. I. Basic yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 39, 40 etc. are mentioned. Further, yellow dyes described in paragraph numbers “0013” to “0112” and “0114” to “0121” of JP-A-2007-191650 are suitable.
Among them, the yellow dye has a relatively large molecular weight, and when recorded on the ink receiving layer containing the porous silica as described above, the solvent and the dye are easily separated from each other, and is excellent in the effect of preventing the occurrence of ink bleeding. What is represented by the following general formula (Y) is preferable. This yellow dye is excellent in ozone resistance and light resistance.

General formula (Y):

In the general formula (Y), R represents a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group, and X represents K, Na, or Li. R may be all the same or different. All Xs may be the same or different.
Examples include the following compounds, but the present invention is not limited thereto.

[Black dye]
Examples of the black dye include disazo, trisazo, and tetraazo dyes. These black dyes may be used in combination with a pigment such as a carbon black dispersion. Preferred examples of the black dye are described in detail in JP-A-2005-307177 and 2006-282795 (paragraph numbers “0068” to “0087”).
Among them, the black dye has a relatively large molecular weight, and when recorded in the ink receiving layer containing the porous silica as described above, the solvent and the dye are easily separated from each other, and the ink bleeding prevention effect is excellent. The following structural formula is preferred. This black dye is excellent in ozone resistance and light resistance.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “part” and “%” are based on mass.

<< Preparation of porous silica >>
As shown below, silica porous bodies A1 to C1 were prepared.
(Silica porous body A1)
50 g of powdered sodium silicate (SiO ₂ / Na ₂ O = 2.00, manufactured by Nippon Chemical Industry Co., Ltd.) was dispersed in 1000 mL of a 0.1M aqueous solution of behenyltrimethylammonium chloride and stirred at 70 ° C. for 3 hours. Thereafter, while heating and stirring at 70 ° C., 2M hydrochloric acid was added to adjust the pH to 8.5, and the mixture was further heated and stirred at 70 ° C. for 3 hours. The solid product was collected by filtration, dispersed in 1000 mL of ion exchange water, and stirred. This filtration / dispersion stirring was repeated 5 times, followed by drying at 40 ° C. for 24 hours. The dried solid product was heated in nitrogen gas at 450 ° C. for 3 hours and then calcined in air at 550 ° C. for 6 hours to obtain porous silica A1.

In the obtained porous silica A1, it was confirmed by X-ray diffraction that hexagonal pores were formed. The average pore size determined by the BJH method was 4.0 nm, the pore volume determined by the BJH method was 1.15 cm ³ / g, the volume average particle size was 3.1 μm, and the specific surface area determined by the BET method was 1041 m ^2. / G.
Further, 60% or more of the pores were within the range of ± 40% of the pores showing the maximum peak in the pore diameter distribution curve. In addition, one strong peak at a diffraction angle corresponding to a d value of 4.9 nm was observed by X-ray diffraction, and the diffraction angle corresponding to a d value smaller than 1.0 nm with a relative intensity greater than 50% of the peak intensity of this peak. No peak was observed. Moreover, the porous silica A1 formed an aggregate of primary particles of 200 nm to 500 nm, and the chlorophyll adsorption amount was 23.1 mg per 100 mg of porous silica.

(Silica porous body B1)
10.5 g of behenyltrimethylammonium chloride was dissolved in 500 mL of ion exchange water and heated to 70 ° C. Further, 4.1 g of gas phase method silica (300CF-5, manufactured by Nippon Aerosil Co., Ltd.) and 25.4 g of sodium hydroxide were dispersed in 500 mL of ion-exchanged water, and the temperature was raised to 70 ° C. Thereafter, both liquid compositions were mixed and stirred at 70 ° C. for 3 hours. Thereafter, while heating and stirring at 70 ° C., 2M hydrochloric acid was added to adjust the pH to 8.5, and the mixture was further heated and stirred at 70 ° C. for 3 hours. The solid product was collected by filtration, dispersed in 1000 mL of ion exchange water, and stirred. This filtration / dispersion stirring was repeated 5 times, followed by drying at 40 ° C. for 24 hours. The dried solid product was heated in nitrogen gas at 450 ° C. for 3 hours and then calcined in air at 570 ° C. for 6 hours to obtain porous silica B1.

It was confirmed by X-ray diffraction that hexagonal pores were formed in the obtained porous silica B1. The average pore diameter determined by the BJH method was 4.5 nm, the pore volume determined by the BJH method was 1.14 cm ³ / g, the volume average particle diameter was 510 nm, and the specific surface area determined by the BET method was 1052 m ² / g. Met.
Further, 60% or more of the pores were within the range of ± 40% of the pores showing the maximum peak in the pore diameter distribution curve. In addition, one strong peak at a diffraction angle corresponding to a d value of 5.0 nm is observed by X-ray diffraction, and the diffraction angle corresponding to a d value of less than 1.0 nm at a relative intensity greater than 50% of the peak intensity of this peak. No peak was observed. Further, the porous silica B1 formed an aggregate of primary particles of about 50 nm, and the chlorophyll adsorption amount was 27.8 mg per 100 mg of porous silica.

(Silica porous body C1)
50 g of powdered sodium silicate (SiO ₂ / Na ₂ O = 2.00, manufactured by Nippon Chemical Industry Co., Ltd.) was dispersed in 1000 mL of a 0.1 M aqueous solution of cetyltrimethylammonium chloride and stirred at 70 ° C. for 3 hours. Thereafter, while heating and stirring at 70 ° C., 2M hydrochloric acid was added to adjust the pH to 8.5, and the mixture was further heated and stirred at 70 ° C. for 3 hours. The solid product was collected by filtration, dispersed in 1000 mL of ion exchange water, and stirred. This filtration / dispersion stirring was repeated 5 times, followed by drying at 40 ° C. for 24 hours. The dried solid product was heated in nitrogen gas at 450 ° C. for 3 hours and then calcined in air at 550 ° C. for 6 hours to obtain porous silica C1.

The obtained porous silica C1 was confirmed to have hexagonal pores formed by X-ray diffraction. The average pore size determined by the BJH method was 2.7 nm, the pore volume determined by the BJH method was 0.94 cm ³ / g, the volume average particle size was 2.9 μm, and the specific surface area determined by the BET method was 941 m ^2. / G.
Further, 60% or more of the pores were within the range of ± 40% of the pores showing the maximum peak in the pore diameter distribution curve. Also, one strong peak at a diffraction angle corresponding to a d value of 3.7 nm was observed by X-ray diffraction, and the diffraction angle corresponding to a d value smaller than 1.0 nm with a relative intensity greater than 50% of the peak intensity of this peak. No peak was observed. The porous silica C1 formed an aggregate of primary particles of 200 nm to 500 nm, and the chlorophyll adsorption amount was 20.8 mg per 100 mg of porous silica.

Next, silica porous bodies A2 to B2 were prepared as shown below.
(Silica porous body A2)
2.1 g of myristyltrimethylammonium chloride (C14 alkyltrimethylammonium salt) was dissolved in 40 g of 0.5 M hydrochloric acid and stirred at 25 ° C. To this, 4.3 g of tetraethoxysilane (TEOS) was added and stirred at pH 2.0 and 25 ° C. for 3 hours. Thereafter, 3.5 g of 25% ammonia solution was added and stirred at pH 9.0 and 25 ° C. for 1 hour. This stirred product was transferred to a tray and dried at 70 ° C. for 24 hours. The obtained solid was fired at 580 ° C. for 10 hours to obtain 1.0 g of porous silica A2.

(Silica porous body B2)
2.1 g of octadecyltrimethylammonium chloride (C18 alkyltrimethylammonium salt) was dissolved in 40 g of 0.5 M hydrochloric acid and stirred at 25 ° C. To this, 4.3 g of tetramethoxysilane (TMOS) was added and stirred at pH 2.0 and 25 ° C. for 3 hours. Thereafter, 3.5 g of 25% ammonia solution was added and stirred at pH 9.0 and 25 ° C. for 0.5 hour. This stirred product was filtered with suction using filter paper (No. 5C manufactured by Advantech), the solid content was dried at 70 ° C. for an hour, and the obtained solid was calcined at 580 ° C. for 10 hours. .4 g was obtained.

After the porous silica A2 and B2 obtained above are dried at 80 ° C. for 1 hour, a fully automatic X-ray diffractometer (RINT ULTIMA II, manufactured by Rigaku Co., Ltd.) is used, and CuKα rays are used as a radiation source in a conventional manner. The X-ray diffraction spectrum was measured, and the peak intensity ratio of d ₁₁₀ and d ₂₀₀ when the peak intensity at d ₁₀₀ was taken as ₁₀₀ was calculated. Further, using a gas adsorption amount measuring device (BELSORP18 Plus, manufactured by Nippon Bell Co., Ltd.), after performing vacuum suction treatment at 180 ° C. for 2 hours, nitrogen adsorption measurement was performed, and the average pore diameter and specific surface area were calculated. The average pore diameter was calculated by the BJH method, and the specific surface area was calculated by the BET method. For the particle size distribution, 100 mg of porous silica is added to 10 ml of ion-exchanged water and dispersed at 20 KHz, 200 W, 4.4 watt / cm ³ using an ultrasonic generator (UD-200, manufactured by Tommy Seiko Co., Ltd.). Thereafter, the obtained dispersion was measured with a laser diffraction / scattering particle size distribution analyzer (COULTER LS230, manufactured by Beckman Coulter, Inc.). The volume average particle diameter was determined as the measured volume-based average diameter.
The ratios of d ₁₀₀ , d ₁₁₀ , and d ₂₀₀ , the average pore diameter, the specific surface area, and the volume average particle diameter are shown in Table 2 below.

As shown in Table 2, the porous silica A2, B2 _are, d _100, d _110, the peak of _{d 200} is _observed, d _100, d _110, the ratio of _{d 200 (d 100: d 110} : d 200) Was in the range of 100: 5.0 to 20.0: 5.0 to 15.0, and had an average particle size in the range of 50 to 500 nm.

Example 1
≪Preparation of inkjet recording medium≫
(Production of support)
Wood pulp consisting of 100 parts of LBKP is beaten to 300 ml Canadian freeness with a double disc refiner, 0.5 parts of epoxidized behenamide, 1.0 part of anionic polyacrylamide, 0.1 part of polyamide polyamine epichlorohydrin, 0.5 part of cationic polyacrylamide All the parts were added at an absolutely dry mass ratio to the pulp, and weighed with a long net paper machine to make a base paper of 170 g / m ² . Next, in order to adjust the surface size of the base paper, 0.04% of a fluorescent whitening agent (“Whiteex BB” manufactured by Sumitomo Chemical Co., Ltd.) is added to a 4% aqueous solution of polyvinyl alcohol, and this is converted into an absolute dry weight. The base paper was impregnated so as to be 0.5 g / m ² , dried, and then subjected to calendar treatment to obtain a base paper adjusted to a density of 1.05.

After the corona discharge treatment was performed on the wire surface (back surface) side of the obtained base paper, high-density polyethylene was coated to a thickness of 19 μm using a melt extruder to form a resin layer composed of a mat surface. (Hereinafter, this resin layer surface is referred to as “back surface”). The back side resin layer is further subjected to a corona discharge treatment, and thereafter, as an antistatic agent, aluminum oxide (“Alumina Sol 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (“Snow manufactured by Nissan Chemical Industries, Ltd.”) are used. Tex O ") the mass ratio of 1: a dispersion dispersed in water at 2, dry weight was coated to a 0.2 g / m ^2.

  Furthermore, after the corona discharge treatment is applied to the felt surface (surface) side where the resin layer is not provided, anatase-type titanium dioxide 10%, a trace amount of ultramarine blue, and a fluorescent whitening agent 0.01% (vs. polyethylene) Low-density polyethylene containing MFR (melt flow rate) 3.8 is melt-extruded to a thickness of 29 μm using a melt extruder, and a high-gloss thermoplastic resin layer is formed on the surface side of the base paper. (Hereinafter, this highly glossy surface is referred to as a “front side”), which is used as a support.

(Preparation of coating solution for upper layer)
(1) Gas phase method silica fine particles, (2) ion-exchanged water, (3) Charol DC-902P, and (4) ZA-30 in the following composition are mixed, and a liquid-liquid collision type disperser (Ultimizer, Sugino Then, the obtained dispersion was heated to 45 ° C. and held for 20 hours. Thereafter, (5) polyvinyl alcohol solution was added to the dispersion at 30 ° C. to prepare an upper layer coating solution. At this time, the mass ratio between the silica fine particles and the water-soluble resin (PB ratio = (1) :( 5)) was 4.0: 1, and the pH of the upper layer coating solution was 3.4, indicating acidity.
<Composition of coating solution for upper layer>
(1) Gas phase method silica fine particles (inorganic fine particles) 8.9 parts (AEROSIL300SF75, manufactured by Nippon Aerosil Co., Ltd.)
(2) Ion-exchanged water: 54.4 parts (3) Charol DC-902P (51.5% aqueous solution): 0.78 parts (dispersant, nitrogen-containing organic cationic polymer, Daiichi Kogyo Seiyaku Co., Ltd.) ) Made)
(4) ZA-30 (manufactured by Daiichi Rare Element Chemical Co., Ltd., zirconyl acetate) ... 0.48 parts (5) Polyvinyl alcohol (water-soluble resin) solution ... 31.2 parts-solution Composition of ~
-PVA-235 ... 2.2 parts (saponification degree 88%, polymerization degree 3500, manufactured by Kuraray Co., Ltd.)
・ Ion-exchanged water ・ ・ ・ 28.2 parts ・ Diethylene glycol monobutyl ether ・ ・ ・ 0.7 parts (Butisenol 20P, Kyowa Hakko Chemical Co., Ltd.)
・ Emulgen 109P (surfactant, manufactured by Kao Corporation) 0.1 parts

(Preparation of coating solution for lower layer)
(1) Gas phase method silica fine particles, (2) Silica porous body A1, (3) ion-exchanged water, (4) Charol DC-902P, (5) ZA-30, and (6) 30% methionine sulfoxide in the following composition Were mixed using a liquid-liquid collision type disperser (Ultimizer, manufactured by Sugino Machine Co., Ltd.), and then this dispersion was heated to 45 ° C. and held for 20 hours. Thereafter, (7) boric acid, (8) polyvinyl alcohol solution, and (9) Superflex 650 were added to the dispersion at 30 ° C. to prepare a lower layer coating solution. At this time, the mass ratio between the silica fine particles and the water-soluble resin (PB ratio = (1) :( 8)) was 3.2: 1. Further, the pH of the coating solution was 3.8, indicating acidity.

<Composition of coating solution for lower layer>
(1) Gas phase method silica fine particles (inorganic fine particles) 7.1 parts (AEROSIL300SF75, manufactured by Nippon Aerosil Co., Ltd.)
(2) Silica porous body A1 ... 1.8 parts (3) Ion exchange water ... 48.5 parts (4) Sharol DC-902P (51.5% aqueous solution) ... 0.78 parts ( Dispersant, nitrogen-containing organic cationic polymer, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(5) ZA-30 ... 0.48 part (Daiichi Rare Element Chemical Co., Ltd., zirconyl acetate)
(6) 30% methionine sulfoxide (sulfur compound) ... 1.76 parts (7) boric acid (crosslinking agent) ... 0.4 parts (8) polyvinyl alcohol (water-soluble resin) solution ... 31.2 parts-Composition of the solution-
-PVA-235 ... 2.2 parts (saponification degree 88%, polymerization degree 3500, manufactured by Kuraray Co., Ltd.)
・ Ion-exchanged water: 28.2 parts ・ Diethylene glycol monobutyl ether: 0.7 parts (Butisenol 20P, manufactured by Kyowa Hakko Chemical Co., Ltd.)
Emulgen 109P (surfactant, manufactured by Kao Corporation) 0.1 part (9) Superflex 650 3.1 parts (nitrogen-containing organic cationic polymer emulsion, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) )

(Formation of ink receiving layer)
After performing the corona discharge treatment on the front surface of the support, the lower surface coating liquid and the upper layer coating liquid are applied to the front surface as follows, and the coating liquid temperature is set to 38 ° C. with an extrusion die coater. As a simultaneous multilayer coating, a coating layer was formed. Specifically, when the simultaneous multilayer coating, the lower layer coating solution at a rate of 105.1 g / m ^2, coated with the following line liquid after line mixing at a rate of 3.3 g / m ^2, the upper layer coating solution at a rate of 106 g / ^{m 2,} after line mixing the following in-line solution at a rate of 13.2 g / ^{m 2,} it was coated on top of the lower layer. At this time, it has a layer structure of upper layer coating solution / lower layer coating solution / support.
<Composition of inline liquid>
Alphain 83 (manufactured by Daimei Chemical Industry Co., Ltd.) 2.0 parts Ion-exchanged water 7.8 parts Himax SC-507 0.2 parts (Dimethylamine / Epichloro Hydrin polycondensate, manufactured by Hymo Co., Ltd.)

The coating layer formed by simultaneous multilayer coating was dried with a hot air dryer at 80 ° C. (wind speed 3 to 8 m / sec) until the solid content concentration of the coating layer became 24%. During this time, the coating layer showed constant rate drying. Immediately after that, it was immersed in a basic solution having the following composition for 3 seconds to deposit 13 g / m ² on the coating layer, and further dried at 72 ° C. for 10 minutes to form an ink receiving layer on the support. At this time, the mass ratio of the porous silica A1 to the total amount of the porous silica A1 and the vapor-phase process silica was 10% by mass.
<Composition of basic solution>
(1) Boric acid ... 1.3 parts (2) Ammonium carbonate (1st grade: manufactured by Kanto Chemical Co., Ltd.) ... 5.0 parts (3) Zircosol AC-7 ... 2.5 parts ( Zirconyl ammonium carbonate (Daiichi Rare Element Chemical Co., Ltd.)
(4) Ion-exchanged water ... 85.2 parts (5) Polyoxyethylene lauryl ether (surfactant) ... 6.0 parts (Emulgen 109P (10% aqueous solution), HLB value 13.6, Kao ( Made by Co., Ltd.)

  As described above, an ink jet recording medium of the present invention in which an ink receiving layer having a dry film thickness of 35 μm was provided on the support was obtained.

<< Preparation of ink set A >>
Deionized water was added to the following components to make 1 liter, and the mixture was stirred for 1 hour while being heated at 30 to 40 ° C. Thereafter, the pH was adjusted to 9 with KOH 10 mol / L, and filtration under reduced pressure was performed using a microfilter having an average pore size of 0.25 μm to prepare an ink liquid for light magenta.
<Composition of ink liquid for light magenta>
-Magenta dye (compound M-1) represented by the following structural formula 7.5 g / L
・ Diethylene glycol 50g / L
・ Urea 10g / L
・ Glycerin 200g / L
・ Triethylene glycol monobutyl ether 120g / L
・ Triethanolamine 6.9g / L
・ Benzotriazole 0.08g / L
・ 2-Pyrrolidone 20g / L
・ Surfinol 465 10.5 g / L
(Surfactant manufactured by Air Products Japan)
・ PROXEL XL-2 (bactericidal agent: manufactured by ICI Japan) 3.5g / L

  Further, magenta ink, light cyan ink, cyan ink, yellow ink and black ink were prepared by changing the dye species and additives as shown in Table 1, and ink set A was prepared.

≪Evaluation≫
Inkjet recording was performed using the inkjet recording medium and ink set A obtained above, and the following evaluations were performed. The evaluation results are shown in Table 3 below.

-1. Ozone resistance
Using an ink jet printer EP-801A (manufactured by Seiko Epson Corp.) loaded with the ink set A instead of a genuine ink set, a yellow, cyan, and magenta solid image was formed on the ink receiving layer of the obtained ink jet recording medium. Each sample was printed, and the sample was stored for 80 hours in an atmosphere of 23 ° C., 60% RH, and ozone concentration of 10 ppm. Then, the residual ratio of the optical density of each solid image of yellow, cyan, and magenta after storage with respect to the optical density of each solid image of yellow, cyan, and magenta before storage was obtained and evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: The residual ratio of single color was 75% or more, and the residual ratio difference of each color was less than 15%.
B: The residual ratio of a single color was 70% or more and less than 75%, or the residual ratio difference of each color was 15% or more and less than 20%.
C: The residual ratio of single color was 60% or more and less than 70%, or the difference in residual ratio of each color was 20% or more and less than 25%.
D: The residual ratio of a single color was less than 60%, or the difference in residual ratio of each color was 25% or more and less than 30%.

-2. Glossy
The glossiness was measured as a 60 ° specular glossiness using a digital variable glossiness meter (UGV-50DP, manufactured by Suga Test Instruments Co., Ltd.) and evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: 45 or more B: 35 or more and less than 45 C: 30 or more and less than 35 D: less than 30

-3. Bleeding
Ink acceptance of the obtained ink jet recording medium using an ink jet printer EP-801A (Seiko Epson Co., Ltd.) loaded with the ink set A instead of a genuine ink set under an environmental condition of 23 ° C. and 50% RH A lattice-like pattern in which magenta and black are adjacent to each other (the length of one side of the lattice is 0.28 mm) is printed in a 3 cm square area. Immediately thereafter, the ink jet recording medium was transferred to an environmental condition of 23 ° C. and 90% RH and left for 14 days. After 14 days, the film was sufficiently dried under the environmental conditions of 23 degrees and 50% RH, and then the degree of bleeding was visually evaluated and ranked according to the following evaluation criteria.
<Evaluation criteria>
A: No bleeding was observed.
B: Slight bleeding was observed, but there was no problem in practical use.
C: Bleeding was large and practically hindered.

(Example 2)
-Preparation of coating solution for ink receiving layer-
In the same manner as in Example 1, an upper layer coating solution and a lower layer coating solution were prepared, and the obtained upper layer coating solution and lower layer coating solution were mixed in the same mass to obtain an ink receiving layer coating solution. At this time, the mass ratio of the silica porous body A1 to the total amount of the silica porous body A1 and the vapor phase method silica is 10% by mass, and the mass ratio of the silica fine particles and the water-soluble resin (PB ratio = (1) :( 8 )) Was 3.6: 1. Further, the pH of the coating solution was 3.6, indicating acidity.

-Formation of ink receiving layer-
A support similar to that in Example 1 was prepared, and the front surface of the support was subjected to corona discharge treatment, and then the ink receiving layer coating solution was applied to the front surface of the extrusion die coater as follows. Then, the coating solution was applied at a temperature of 38 ° C. to form a coating layer. Specifically, a coating solution at a rate of 105.1 g / ^{m 2,} after the following in-line solution were in-line mixing at a rate of 3.3 g / ^{m 2,} coated on a support.
~ Composition of inline liquid ~
Alphain 83 (manufactured by Daimei Chemical Industry Co., Ltd.) 2.0 parts Ion-exchanged water 7.8 parts Himax SC-507 0.2 parts (Dimethylamine / Epichloro Hydrin polycondensate, manufactured by Hymo Co., Ltd.)

Next, the coating layer formed by coating was dried with a hot air dryer at 80 ° C. (wind speed of 3 to 8 m / sec) until the solid content concentration of the coating layer became 24%. This coating layer showed constant rate drying during this period. Immediately after that, it was immersed in a basic solution having the following composition for 3 seconds to deposit 13 g / m ² on the coating layer, and further dried at 72 ° C. for 10 minutes to form a single ink receiving layer on the support. did.
<Composition of basic solution>
(1) Boric acid ... 1.3 parts (2) Ammonium carbonate (1st grade: manufactured by Kanto Chemical Co., Ltd.) ... 5.0 parts (3) Zircosol AC-7 ... 2.5 parts ( Zirconyl ammonium carbonate (Daiichi Rare Element Chemical Co., Ltd.)
(4) Ion-exchanged water ... 85.2 parts (5) Polyoxyethylene lauryl ether (surfactant) ... 6.0 parts (Emulgen 109P (10% aqueous solution), HLB value 13.6, Kao ( Made by Co., Ltd.)

  As described above, an ink jet recording medium in which an ink receiving layer having a dry film thickness of 35 μm was provided on a support was produced. Using this, ink jet recording and evaluation were performed and evaluated. The evaluation results are shown in Table 3 below.

(Example 3)
In Example 2, the amount of vapor phase silica in the coating solution was changed from 7.1 parts to 5.3 parts, and the amount of porous silica A1 was changed from 1.8 parts to 3.6 parts (silica porous body A1 In addition, an ink jet recording medium was prepared in the same manner as in Example 2 except that the mass ratio of the porous silica A1 to the total amount of the vapor phase silica was changed from 10% to 20%. Recording and evaluation were performed. The evaluation results are shown in Table 3 below.

(Examples 4 to 7)
In Example 2, an ink jet recording medium was prepared in the same manner as in Example 2 except that the silica porous body A1 in the coating solution composition was changed to the silica porous body B1, C1, A2, or B2. Were used for inkjet recording and evaluation. The evaluation results are shown in Table 3 below.

(Example 8)
In Example 2, except that ZA-30 (zirconyl acetate) in the coating solution composition was not added, an ink jet recording medium was prepared in the same manner as in Example 2, and ink jet recording and evaluation were performed using this. It was. The evaluation results are shown in Table 3 below.

Example 9
In Example 2, ink set B was used in which compound M-1 (magenta dye) in each composition of light magenta ink liquid and magenta ink liquid constituting ink set A was replaced with magenta dye having the following structure. Except for this, an ink jet recording medium was prepared in the same manner as in Example 2, and ink jet recording and evaluation were performed using this. The evaluation results are shown in Table 3 below.

(Comparative Example 1)
In Example 2, the preparation of the coating liquid for the ink receiving layer was carried out except that the porous silica A1 was not used and the amount of the vapor phase method silica fine particles was changed from 7.1 parts to 8.9 parts. In the same manner as in No. 2, an ink jet recording medium was produced, and ink jet recording and evaluation were performed using this. The evaluation results are shown in Table 3 below.

(Comparative Example 2)
In Example 1, when preparing the coating solution for the lower layer, the porous silica A1 was not used, and the amount of the vapor phase method silica fine particles was changed from 7.1 parts to 5.3 parts. Similarly, an ink jet recording medium was produced, and ink jet recording and evaluation were performed using the medium. The evaluation results are shown in Table 3 below.

(Comparative Example 3)
In Example 2, when preparing the upper layer coating liquid, the silica porous body A1 was used instead of the gas phase method silica fine particles, and when preparing the lower layer coating liquid, the gas phase method silica fine particles were not used, but the silica porous body A1. An ink jet recording medium was produced in the same manner as in Example 2 except that the amount was changed from 1.8 parts to 8.9 parts, and ink jet recording and evaluation were performed using this. The evaluation results are shown in Table 3 below.

(Comparative Example 4)
In Example 2, an inkjet recording medium was prepared and used in the same manner as Example 2 except that the porous silica A1 was used in place of the vapor phase silica fine particles when preparing the upper layer coating liquid. Inkjet recording and evaluation were performed. The evaluation results are shown in Table 3 below.

  As shown in Table 3, in the example, the effect of preventing the occurrence of ink bleeding was remarkable, and a fine image could be recorded. Moreover, it was excellent in ozone resistance and gloss was also good. On the other hand, in the comparative example, ink bleeding was not suppressed, and gloss and ozone resistance were reduced.

Claims (11)

  Gas phase method silica, and a porous silica material having hexagonal pores having an average pore size of 0.8 nm to 20 nm and a volume average particle size of 50 nm to 20 μm, the gas phase method silica and the An ink jet recording medium having an ink receiving layer on a support, wherein the mass ratio of the porous silica to the total amount of porous silica is less than 50% by mass. The porous silica has a specific surface area of a 400m ² / g~2000m ² / g, in claim 1, wherein the pore volume is 0.1cm ³ /g~3.0cm ³ / g The inkjet recording medium as described.   The porous silica has one or more first peaks indicating a diffraction angle corresponding to a d value larger than 2.0 nm in a X-ray diffraction spectrum by CuKα rays, and diffraction corresponding to a d value smaller than 1.0 nm. The peak intensity of the second peak indicating the angle is not more than 200% relative to the peak intensity of the peak indicating the maximum intensity among the first peaks, or does not have the second peak. The ink jet recording medium according to claim 1, wherein:   The inkjet recording medium according to any one of claims 1 to 3, wherein the porous silica has an average primary particle diameter of 30 nm to 200 nm.   5. The inkjet recording medium according to claim 1, wherein the porous silica has a volume average particle diameter of 50 nm to 500 nm. In the X-ray diffraction spectrum by CuKα ray, the porous silica is represented by a ratio of peak intensity d ₁₀₀ : d ₁₁₀ : d ₂₀₀ = 100: 5.0 to 20.0: 5.0 to 15.0, The volume average particle diameter is 50 nm to 500 nm, and the inkjet recording medium according to any one of claims 1 and 4 to 5.   The inkjet recording medium according to any one of claims 1 to 6, wherein the support is a resin-coated paper in which both sides of a base paper are coated with a resin layer.   The inkjet recording medium according to claim 1, wherein the ink receiving layer further contains a mordant.   The ink receiving layer has a layer structure including two or more layers including a layer containing the porous silica material and a layer containing the vapor phase silica in order from the support side. The ink jet recording medium according to claim 8.   An inkjet recording method for recording an image by applying a dye-based ink containing a dye to the inkjet recording medium according to any one of claims 1 to 9 by an inkjet method. The inkjet recording method according to claim 10, wherein a magenta ink containing at least a magenta dye represented by the following general formula (M) is applied as the dye-based ink.

[Wherein, R represents a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group, and X represents Li, Na, or K. ]