JP4243260B2 - Inkjet recording medium and method for producing the same - Google Patents

Description

  The present invention relates to an ink jet recording medium comprising a support, at least one ink receiving layer formed on the surface of the support, and a gloss developing layer formed as the uppermost layer.

  Inkjet recording is a method of recording images, characters, etc. by ejecting micro droplets of ink by various operating principles and depositing them on an inkjet recording sheet. Recording is easy at high speed, low noise, and full color. It has advantages such as high pattern flexibility and no need for development-fixing, and is rapidly spreading in various applications as a recording system for characters and various figures. Furthermore, an image formed by an inkjet recording method using a multicolor ink containing pigments such as yellow, magenta, cyan, and black is compared with multicolor printing by a plate making method or printing by a color photographic method, When it is possible to obtain an inferior recorded image and it is sufficient to produce a small number of copies, the inkjet recording method is being widely applied to the field of full-color image recording because it is less expensive than development by silver salt photography.

  As an inkjet recording sheet used in the inkjet recording system, development of an inkjet recording apparatus and an ink composition surface is active so that general paper such as high-quality paper and coated paper used for normal printing and writing can be used. However, with the improvement in performance of inkjet recording devices and the expansion of applications such as higher speed, higher definition, and full color, more advanced characteristics have been required for inkjet recording sheets. It was. In other words, as an inkjet recording sheet, the density of the printed dots is high, the color tone is bright and vivid, the ink absorption is fast, the ink does not run out or bleed even when the printed dots overlap, the printed dot sheet There are various requirements such as that the diffusion in the surface direction does not become larger than necessary, the shape of the printed dot is close to a perfect circle, the periphery is smooth and unblurred, the whiteness is high, and the contrast with the printed dot is large. The need to meet has arisen.

  As a conventional general inkjet recording sheet, a pigment and a binder such as amorphous silica or synthetic silica, clay, calcium carbonate and a binder are mainly contained on at least one surface of a support of a recording sheet such as a base paper. It is known that the ink receiving layer is formed by coating the coating liquid using a blade coater, air knife coater, roll coater, bar coater, gravure coater, rod blade coater, lip coater, curtain coater, die coater, etc. Yes.

  The above-described ink receiving layer to which a porous pigment is applied improves color reproducibility and image reproducibility. The ink receiving layer having ink absorptivity needs to have many voids in the ink receiving layer in order to absorb and hold ink. However, the ink-receiving layer with many voids is scattered because the incident light to the ink-receiving layer is scattered and transmission is blocked, so that the ink becomes opaque, and it becomes difficult for light to reach the ink that has penetrated the voids, so the image becomes whitish. Color reproducibility and color density are reduced. Further, since the ink receiving layer having many voids has a porous surface, it is difficult to desire high gloss.

  Conventionally, an ink jet recording sheet in which an ink receiving layer contains alumina or alumina hydrate has been proposed (see, for example, Patent Document 1). Alumina or alumina hydrate is excellent in gloss and easily forms fine voids. Therefore, it is possible to improve gloss and improve the degree of light reaching the ink that has penetrated into the voids.

In addition, proposals have been made to develop gloss in an inkjet recording sheet by using colloidal silica as the uppermost layer (see, for example, Patent Documents 2 and 3). Patent Document 2 proposes a method in which colloidal silica is used for improving glossiness, and the cast is performed after treatment with an aqueous solution containing a cationic polymer electrolyte. Patent Document 3 proposes an ink jet recording sheet having an uppermost layer containing two or more kinds of colloidal silica having different primary particle diameters.
JP 2004-9523 A Japanese Patent Laid-Open No. 2-27487 JP-A-6-183134

  Ink used in ink jet printers is mainly dye type, but printers equipped with pigment ink are beginning to become popular in order to improve the fading property of the printing portion, which is a drawback of dye type ink. Printers equipped with this pigment ink include a type in which only black ink is equipped with pigment ink, or a printer in which all color pigment inks are installed.

  In the dye ink, the dye as the color material is soluble in water as the medium, and the dye exists in the ink medium in a molecular state. The pigment ink exists in a state where pigment particles as a color material are dispersed in water as a medium. Dye inks have high color developability but are inferior in light resistance. Pigment inks have a tendency to improve light resistance although their color developability is lower than that of dye inks.

  In the dye ink, the color material penetrates into the recording medium. On the other hand, in the pigment ink, more pigment particles, which are color materials, remain on the surface of the inkjet recording sheet. In the ink jet recording sheets described in Patent Documents 1 to 3, it is difficult to obtain excellent ink absorbency and high print density at the same time using either dye ink or pigment ink having different characteristics as described above. It was not possible to obtain a high quality image.

  The present invention provides an ink jet recording medium which has an appropriate gloss and has excellent ink absorbability and high print density regardless of whether dye ink or pigment ink is used for printing by an ink jet recording apparatus. With the goal.

  In order to solve the above problems, the present inventor has found that the problem is solved mainly by the following means, as a result of various studies on the composition and the coating amount of the glossy layer of the ink jet recording medium.

The present invention is an inkjet recording medium comprising a support, at least one ink receiving layer formed on the surface of the support, and a gloss developing layer formed on the top layer, the gloss developing layer Is a dry dry coating amount of 7 to 20 g of a coating liquid for forming a glossy layer containing the first component and the second component so that the absolute dry weight ratio is in the range of 10:90 to 60:40. formed in / m ² was coated, the first component has an average primary particle size made different at least two colloidal silica, the second component consists of alumina and / or hydrated alumina, the Alumina and the alumina hydrate have an average primary particle diameter in the range of 12 to 18 nm and a BET specific surface area in the range of 150 to 190 m ² / g.

  The first component preferably contains colloidal silica having an average primary particle diameter of 30 nm or less and colloidal silica having an average primary particle diameter in the range of 60 to 150 nm.

  According to the ink jet recording medium of the present invention, an ink jet recording medium having a 60 degree specular gloss of 45% or more as defined in JIS P 8142 can be obtained. The medium.

  In the ink jet recording medium of the present invention, it is preferable that the glossiness is imparted by pressing the uppermost portion onto a mirror surface roll in a wet state, drying and glossing. The “uppermost part” here is not particularly limited as long as it is in a range sufficient to impart gloss to the ink jet recording medium, but may be, for example, the entire glossy layer.

In the present invention, the step (a) of coating the ink receiving layer on the surface of the support, and the first component and the second component have an absolute dry weight ratio in the range of 10:90 to 60:40. A step (b) of applying a gloss-expressing layer forming coating solution at an absolute dry coating amount of 7 to 20 g / m ² to coat the gloss-expressing layer on the uppermost layer, and the uppermost portion in a wet state Step (c), which is pressure-bonded to a mirror surface roll, dried and gloss-treated in the above order, the first component is composed of at least two types of colloidal silica having different average primary particle sizes, and the second component Is made of alumina and / or alumina hydrate, and the alumina and the alumina hydrate have an average primary particle diameter in the range of 12 to 18 nm and a BET specific surface area in the range of 150 to 190 m ² / g. The method for producing an inkjet recording medium according to the above.

  INDUSTRIAL APPLICABILITY According to the present invention, an ink jet recording medium having an appropriate glossiness and excellent in ink absorbability and capable of obtaining a high print density regardless of whether dye ink or pigment ink is used for printing by an ink jet recording apparatus, and a method for producing the same Is obtained.

  The present invention relates to an inkjet recording medium comprising a support, at least one ink receiving layer formed on the surface of the support, and a gloss developing layer formed on the uppermost layer. The layer includes a colloidal silica component (first component) and an alumina component (second component). The colloidal silica component is composed of at least two types of colloidal silica having different average primary particle sizes, and the alumina component is composed of alumina and / or alumina hydrate.

  As the colloidal silica according to the present invention, a colloidal solution in which ultrafine particles of inorganic silicic acid are dispersed using water or an organic solvent as a dispersion medium is used. In the present invention, it is preferable to use colloidal silica that has been previously treated with an organic cation as the colloidal silica used in the glossy layer. Colloidal silica treated with organic cation is generally obtained by reacting silica with an organic cationic compound having an organic cationic group such as a primary to tertiary amine group or a quaternary ammonium base, At least the silica surface is cationically charged.

  It is possible to use anionic colloidal silica or inorganic colloidal colloidal silica as the colloidal silica used in the glossy layer. However, the cation is used for the purpose of obtaining excellent absorbency for pigment ink and excellent printing density for dyed ink. It is preferable to use a colloidal silica. That is, colloidal silica treated with an organic cation as colloidal silica in order to obtain high print density, color reproducibility, and image clarity while maintaining excellent ink absorbency for both dye ink and pigment ink. Is preferably used. As described above, as the colloidal silica, either cationic colloidal silica or anionic colloidal silica may be used, but in order to improve the dispersibility of the colloidal silica, the polarity of the colloidal silica used is one. It is preferable to be unified.

  The gloss developing layer according to the present invention includes at least two types of colloidal silica having different average primary particle diameters, an average primary particle diameter of 50 nm or less, and an average primary particle diameter in the range of 60 to 300 nm. A combination of colloidal silica having an average primary particle diameter of 30 nm or less and colloidal silica having an average primary particle diameter in the range of 60 to 150 nm is more preferable. In addition, the colloidal silica having a smaller average primary particle diameter and the colloidal silica having a larger average primary particle diameter have an absolute dry weight ratio of 10:90 to 90: It is preferable to be within the range of 10.

  The gloss-expressing layer containing colloidal silica has a very small colloidal silica particle size and fine surface irregularities, the surface of the colloidal silica particles is hydrophilic and has good wettability with water-based inks, and inorganic Because it is a particle, it does not dissolve or swell due to ink, is stable mechanically and thermally, does not cause deformation of the particle, and preserves inter-particle voids. It is considered that the gloss and the gloss of the image recording portion can be arranged side by side. Furthermore, colloidal silica having a small average primary particle size (for example, 30 nm or less) contributes to the absorbability of the pigment ink, and colloidal silica having a large average primary particle size (for example, in the range of 60 to 150 nm) It is thought that it contributes to the improvement of the printing density of the pigment ink. If the average primary particle diameter of the colloidal silica exceeds 150 nm, the opacity of the colloidal silica is increased and the concealing property is exhibited, so that the color property of the printed portion is deteriorated, which is not preferable.

The glossy expression layer according to the present invention contains alumina and / or alumina hydrate. In the gloss developing layer, in order to obtain a desired gloss and a desired ink absorbency, the alumina and the alumina hydrate preferably have an average primary particle diameter in the range of 12 to 18 nm and a BET specific surface area of 150. Use the thing in the range of -190m < ² > / g. Alumina and alumina hydrate are aluminum oxide and its hydrates, which may be crystalline or amorphous, and are not limited in form, and have an amorphous shape, a spherical shape, a plate shape, and the like. Things can be used. Different forms may be used in combination.

As the alumina according to the present invention, γ-alumina which is a γ-type crystal of aluminum oxide is preferable, and δ group crystal is particularly preferable. The alumina hydrate according to the present invention is represented by a composition formula of Al ₂ O ₃ .nH ₂ O (n = 1 to 3). When n is 1, it represents boehmite-structured alumina hydrate, and when n is greater than 1 and less than 3, it represents pseudoboehmite-structured alumina hydrate. The alumina hydrate can be obtained by a known production method such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, hydrolysis of aluminate, and the like.

  In the dispersion of alumina or alumina hydrate according to the present invention, it is not necessary to use a dispersant, but it is preferable to use a monovalent acid as the dispersant. As the monovalent acid, lactic acid, acetic acid, formic acid, nitric acid, hydrochloric acid, and hydrobromic acid are preferably used.

  The average primary particle diameter of the colloidal silica, alumina, and alumina hydrate described above is the average value of the diameter of the primary particles for the pigment whose primary particle shape is substantially spherical, and the primary particle shape is spindle-shaped. The pigment is the average value of the average particle diameter which is the average value of the major axis and minor axis of each primary particle.

  The inkjet recording medium according to the present invention has a 60-degree specular gloss measured according to JIS P 8142, preferably 45% or more. If it is less than 45%, glossiness is insufficient, which is not preferable.

  In one embodiment of the ink jet recording medium according to the present invention, a gloss developing layer is coated by applying a coating liquid for forming a gloss developing layer on the ink receiving layer. For the purpose of imparting gloss, calendar processing may be performed using a calendar device such as a machine calendar, a TG calendar, or a soft calendar. Furthermore, in order to improve glossiness, you may cast on the uppermost part. The cast treatment is a processing method in which the uppermost part (which may be the entire glossy layer or the upper part of the glossy layer) may be in a swollen state, and pressed onto a heated mirror roll to be mirror finished. For example, a direct method, a gelation method, a rewet method and the like can be mentioned. In addition, as a method for improving the glossiness, a method may be used in which a smooth film is brought into close contact with the uppermost portion in a swollen state, peeled off, and mirror-finished.

In the present invention, the absolute dry coating amount of the coating liquid for forming a glossy layer is 7 to 20 g / m ² . Although it is affected by the smoothness of the ink receiving layer and the drying conditions of the glossy layer, if it is less than 7 g / m ² , sufficient gloss cannot be obtained and the color developability also decreases, resulting in 20 g / m ^2. If it exceeds 1, the ink absorptivity deteriorates and the printed surface cracks.

  The glossy layer forming coating solution according to the present invention contains a colloidal silica component and an alumina component in a ratio of 10:90 to 60:40 in an absolutely dry weight ratio. By containing a colloidal silica component and an alumina component within such a range, a glossy expression layer that exhibits both characteristics is formed. Note that the glossy layer may contain a pigment other than colloidal silica, alumina, and alumina hydrate.

  In order to obtain a glossy layer having sufficient strength, it is preferable to use 5 to 30 parts by weight of a binder in combination with 100 parts by weight of the pigment.

  The binder is not particularly limited as long as it is a binder that can be generally used for a coating sheet. For example, polyvinyl alcohol or derivatives thereof, starch derivatives such as oxidized starch, cellulose derivatives such as methylcellulose and carboxymethylcellulose, casein, and soy protein Gelatin, polyethylene oxide, polypropylene oxide, polyethylene glycol, polyvinyl ether, polyacrylamide, polyvinyl pyrrolidone, polyacrylate, maleic acid resin, alginate and the like can be used.

  The ink receiving layer according to an embodiment of the present invention is a coating layer that is coated between the glossy expression layer and the support and absorbs the solvent component in the ink. The solvent component is removed from the glossy expression layer by the ink receiving layer, and the problem of ink overflow can be avoided.

  The ink receiving layer according to the present invention contains a pigment. As the pigment, a synthetic amorphous silica having good ink absorbability and high print sharpness is desirable. However, any pigment that can add sufficient characteristics as the ink-receiving layer may be used alone or in combination with synthetic amorphous silica. Examples of such pigments include kaolin, clay, calcined clay, calcium carbonate, and aluminum hydroxide.

The absolute dry coating amount of the coating liquid for forming the ink receiving layer according to the present invention (hereinafter referred to as “ink receiving layer coating liquid”) is preferably 3 to 25 g / m ² . The ink receiving layer forming coating liquid according to the present invention preferably contains a water-soluble binder. By the water-soluble binder, adhesiveness is developed at the interface between the glossy layer and the ink receiving layer, and the adhesiveness at the interface is improved. Water-soluble binders used in the ink receiving layer forming coating liquid include polyvinyl alcohol or derivatives thereof, cellulose derivatives such as methyl cellulose and carboxymethyl cellulose, casein, soy protein, gelatin, polyethylene oxide, polypropylene oxide, polyethylene glycol, polyvinyl Examples include ether, polyacrylamide, polyvinyl pyrrolidone, polyacrylate, maleic resin, and alginate. Polyvinyl alcohol is particularly preferably used as the binder for the ink receiving layer forming coating solution.

  In addition, the ink receiving layer forming coating solution includes, as additives, a cationic dye fixing agent, a pigment dispersant, a thickener, a fluidity improver, an antifoaming agent, a defoaming agent, a release agent, a foaming agent, Add penetrants, coloring dyes, colored pigments, fluorescent brighteners, UV absorbers, preservatives, antifungal agents, water resistance agents, wet paper strength enhancers, dry paper strength enhancers, and antioxidants as appropriate. You can also.

  The method of applying the glossy expression layer and the ink receiving layer according to the present invention can be performed using various apparatuses such as various blade coaters, roll coaters, air knife coaters, bar coaters, rod blade coaters, curtain coaters and the like.

  In order to impart curl aptitude, a back coat layer may be provided on the surface of the support opposite to the surface on which the ink receiving layer is formed.

  As a support that can be used in the ink jet recording medium according to the present invention, paper, film, nonwoven fabric, or a composite thereof can be generally used, but is not particularly limited thereto. For example, chemical pulps such as LBKP and NBKP, mechanical pulps such as GP, PGW, RMP, TMP, CTMP, CMP and CGP, waste paper pulp such as DIP, or wood pulp and a known pigment as a main component, binder and sizing agent And various materials such as long net paper machine, circular net paper machine, twin wire paper machine, etc., with one or more various additives such as fixing agent, yield improver, cationizing agent, paper strength enhancer added as appropriate The base paper produced by the machine, the base paper provided with an anchor coat layer with starch, polyvinyl alcohol, etc., and the art paper, coated paper, cast coat paper, etc., provided with a coat layer on the base paper. Work paper can also be used. A porous synthetic resin sheet having open cells can also be used as the support.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited to these examples. Further, “parts” and “%” shown in Examples and Comparative Examples represent parts by weight and parts by weight unless otherwise specified. In addition, about the particle diameter shown to the Example and the comparative example, it is the average particle diameter calculated | required by the dynamic light scattering method.

1. Production of Inkjet Recording Paper In the examples and comparative examples shown below, the support was blended with 100 parts by weight of LBKP and 30/10/10 parts by weight of each of sulfuric acid band / size agent / talc, and the blended liquid was made into a long net papermaking. A paper base produced by paper making using a machine and coated with starch on the paper surface was used in common.

  Table 1 shows the compositions of the coating liquid for forming the glossy layer of the inkjet recording papers of Examples 1 to 6 and Comparative Examples 1 to 4.

(Example 1)
1) Coating of ink receiving layer The ink receiving layer was coated on the surface of the support. The ink-receiving layer-forming coating solution has a composition of 100 parts of wet synthetic amorphous silica (silica fine seal X45: manufactured by Tokuyama Corporation), 55 parts of polyvinyl alcohol (PVA117: manufactured by Kuraray Co., Ltd.) having a polymerization degree of 1700, and cationic aqueous solution. The synthetic resin (SR1001: manufactured by Sumitomo Chemical Co., Ltd.) is 10 parts, and the wet synthetic amorphous silica is dispersed in distilled water so as to have a solid content of 18% with a homogenizer. The mixture was diluted with distilled water so as to have a content of 17% and prepared. This coating solution was applied to the support with a Mayer bar so that the dry coating amount was 10 g / m ² and dried.

2) Coating of gloss developing layer A gloss developing layer was coated on the upper surface of the ink receiving layer. The coating liquid for forming the glossy layer was mixed with a lab stirrer with the composition shown in Table 1, and diluted with distilled water so that the solid content of the whole liquid mixture was 20%, and the mixture was prepared. This coating solution was applied to the support with a Mayer bar so that the dry coating amount was 15 g / m ² and dried. Thereafter, the uppermost surface was rewet with hot water of 90 ° C., the surface was pressure-bonded to a mirror-finished mirror-finished roll, and dried to obtain a glossy inkjet recording paper of Example 1.

(Example 2)
A glossy inkjet recording paper of Example 2 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was that shown in Table 1.

(Example 3)
A glossy inkjet recording paper of Example 3 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming a glossy layer was the composition shown in Table 1.

(Example 4)
A glossy ink jet recording paper of Example 4 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was that shown in Table 1.

(Example 5)
A glossy inkjet recording paper of Example 5 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was the composition shown in Table 1.

(Example 6)
A glossy ink jet recording paper of Example 6 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was that shown in Table 1.

(Comparative Example 1)
A glossy inkjet recording paper of Comparative Example 1 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was that shown in Table 1.

(Comparative Example 2)
A glossy inkjet recording paper of Comparative Example 2 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was the composition shown in Table 1.

(Comparative Example 3)
A glossy inkjet recording paper of Comparative Example 3 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was that shown in Table 1.

(Comparative Example 4)
A glossy inkjet recording paper of Comparative Example 4 was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the glossy layer was that shown in Table 1.

(Comparative Example 5)
In the gloss developing layer forming step, the coating liquid for forming the gloss developing layer was applied to the support with a Mayer bar so that the dry coating amount was 5 g / m ^2, and dried, as in Example 1. Thus, a glossy inkjet recording paper of Comparative Example 5 was obtained.

(Comparative Example 6)
In the gloss developing layer forming step, the coating liquid for forming the gloss developing layer was applied to the support with a Mayer bar so that the dry coating amount was 25 g / m ^2, and was the same as in Example 1 except that it was dried. Thus, a glossy inkjet recording paper of Comparative Example 6 was obtained.

2. Evaluation The inkjet recording papers obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were evaluated for the specular gloss, print density, and ink bleeding by the following methods. Printing density and ink bleeding were recorded with PX-G900 manufactured by Seiko Epson, an ink jet printer for pigment ink, and pure dye ink was recorded with PM-G700, an ink jet printer for dye ink. Was recorded and evaluated. The results obtained are shown in Table 2.

  Specular Gloss: The specular gloss was measured according to a 60-degree specular gloss test method for paper and paperboard according to JIS P 8142. The specular glossiness of 45% or more was evaluated as ◎, 30% or more and less than 45% as ○, 20% or more and less than 30% as Δ, and less than 20% as ×.

  Print density: The print density was measured with a reflection densitometer (Spectro Eye: manufactured by Gretag Macbeth). The total print density of black, cyan, magenta, and yellow is 4.80 or more, 、 ４ 4.70 or more and less than 4.80, 、 ４, 4.60 or more and less than 4.70, or less than 4.60. Was evaluated as x.

  Ink bleeding: The ink bleeding was evaluated visually. If there is no bleeding after printing, ◎. After printing, bleeding is slightly observed at the color boundary of 300% printing, but the boundary can be discriminated. If there is no substantial problem, ○, color after printing is 300% printing. When the blur was conspicuous at the boundary and it was difficult to discriminate the boundary, it was evaluated as Δ, and after printing, the blur was conspicuous even at the 100% print boundary and the border was difficult to discriminate.

  From the results shown in Table 2, the inkjet recording papers of Examples 1 to 6 of the present invention have excellent gloss as compared with the inkjet recording papers of Comparative Examples 1 to 6, and any of the pigment ink and the dye ink It can be seen that a high print density is obtained for ink printing, and there is almost no ink bleeding. None of the inkjet recording papers of Comparative Examples 1 to 6 had excellent characteristics with respect to any of the pigment ink and the dye ink.

  The ink jet recording medium of the present invention can be used as a recording medium having excellent characteristics with respect to an ink jet recording system using either pigment ink or dye ink. In addition, by performing recording by the ink jet method using the recording medium according to the present invention, it is possible to provide a recorded medium having excellent gloss, high printing density, and almost no ink bleeding, so that it has an excellent appearance. It is particularly suitable when there is a need to provide a recorded medium.

Claims (4)

A dye ink and pigment comprising: a support; at least one ink receiving layer formed on the surface of the support; and a gloss developing layer formed on the uppermost layer , wherein the gloss developing layer is cast. An ink jet recording medium that also serves as an ink,
The gloss developing layer is a dry coating coating solution for forming a gloss developing layer containing the first component and the second component so that the absolute dry weight ratio is in the range of 10:90 to 60:40. Formed by coating at an amount of 7-20 g / m ² ,
The first component includes colloidal silica having an average primary particle diameter of 30 nm or less and colloidal silica having an average primary particle diameter in the range of 60 to 150 nm.
The second component is composed of alumina and / or alumina hydrate, and the alumina and the alumina hydrate have an average primary particle diameter in the range of 12 to 18 nm and a BET specific surface area of 150 to 190 m ² /. Ink recording medium for both dye ink and pigment ink in the range of g. The medium for inkjet recording according to claim 1, wherein the 60-degree specular gloss specified in JIS P 8142 is 45% or more. The ink jet recording medium according to claim 1, wherein the uppermost portion is pressed into a mirror surface roll in a wet state, and then dried and gloss-treated. A step (a) of coating an ink receiving layer on the surface of the support;
A gloss-expressing layer forming coating solution containing the first component and the second component so that the absolute dry weight ratio is within the range of 10:90 to 60:40 is the absolute dry coating amount of 7 to 20 g / m. ^The step (b) of applying the glossy layer on the uppermost layer by coating in step 2 and the cast processing step (c) of pressing the uppermost portion in a wet state onto the mirror roll and drying to give the gloss treatment are performed in the above order. Have at least
The first component includes colloidal silica having an average primary particle diameter of 30 nm or less and colloidal silica having an average primary particle diameter in the range of 60 to 150 nm.
The second component is composed of alumina and / or alumina hydrate, and the alumina and the alumina hydrate have an average primary particle diameter in the range of 12 to 18 nm and a BET specific surface area of 150 to 190 m ² /. A method for producing an inkjet recording medium for both dye ink and pigment ink, which falls within the range of g.