JP2007276233A - Inkjet recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording medium enabling attainment of an excellent image quality approximate to a silver halide photography. <P>SOLUTION: In the inkjet recording medium having a recording surface formed by providing a coating layer on a low-air-permeable or non-air-impermeable substrate, the 20-degree glossiness of the recording surface satisfies formulas (1) and (2). The formula (1) is G≥20% and the formula (2) is 1.3≥Gb/G≥0.9. In the formulas, G denotes the 20-degree glossiness according to JIS-Z8741 of the recording surface that undergoes no inkjet recording and Gb denotes the 20-degree glossiness according to JIS-Z8741 of the recording surface inkjet-recorded with a black dye ink. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording material suitable for outputting photographic images and the like.

  The inkjet recording method that forms an image on a recording medium by ejecting water-based ink from fine nozzles is easy to make full color, enables high-speed recording, and is less expensive than other printing devices for printing in small quantities. For some reason, it is widely used in terminal printers, facsimiles, plotters, form printing, and the like. In particular, recently, with the rapid spread of printers, high definition and high speed, and the advent of digital cameras, recording media (hereinafter referred to as ink jet recording media) used in this recording system are required to have advanced characteristics. It is like that. Such properties include recording properties such as fast ink absorption, high recording density, excellent water resistance and storage stability, and in particular, there is a strong demand for image quality comparable to silver salt photography. .

  The ink jet recording body is usually constituted by providing a coating layer on a support made of paper, resin-coated paper, resin film, etc., and the surface of the coating layer becomes a recording surface on which ink jet recording is performed. The coating layer includes a layer called an ink receiving layer for receiving ink and a layer called a gloss layer for giving surface gloss to an ink jet recording body.

When an image is formed with ink on such an ink jet recording body using paper as a support, a phenomenon called so-called cockling is observed in which the ink jet recording body stretches and undulates due to the influence of the solvent contained in the ink. Often. When cockling occurs, not only the appearance of the obtained printed matter is impaired, but also the ink-jet recording body is soiled or torn due to contact between the cocked ink-jet recording body and the recording head. The head may break down.
On the other hand, in the ink jet recording body using a resin-coated paper or resin film having low air permeability as a support, cockling is effectively suppressed and closer to a silver salt photograph than that using paper as a support. There is an advantage that a texture can be obtained. Inkjet recording bodies using resin-coated paper or resin film with low air permeability as a support are disclosed in, for example, Patent Documents 1 to 3 and the like.
JP-A-9-183267 JP-A-9-286165 JP-A-8-174992

  However, even when ink jet recording is performed on an ink jet recording body in which a resin-coated paper or resin film having low air permeability is used as a support, an excellent image quality close to a silver salt photograph may not be obtained.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an ink jet recording body capable of obtaining an excellent image quality close to a silver salt photograph.

  As a result of intensive studies on an ink jet recording body capable of forming an excellent image quality close to that of a silver salt photograph, the present inventors have found that the 20-degree glossiness of the recording surface on which the ink jet recording is performed is large in the image quality of the ink jet recording body. I found it to have an impact. Further, the inventor of the present invention determines that the 20-degree glossiness of the recording surface depends on the presence or absence (before and after) of ink-jet recording, and the 20-degree glossiness of the recording surface on which ink-jet recording is performed and According to the ink jet recording medium having a specific relationship and the 20-degree glossiness of the recording surface not subjected to ink jet recording being in a specific range, an excellent image quality equivalent to that of a silver salt photograph can be stably formed. As a result, the present invention has been completed.

The ink jet recording body of the present invention is an ink jet recording body in which a coating layer is provided on a low air-permeable or non-air-permeable support and a recording surface is formed. ) And (2) are satisfied.
G ≧ 20% (1)
1.3 ≧ Gb / G ≧ 0.9 (2)
(In the formula, G indicates the 20-degree glossiness according to JIS-Z8741 of the recording surface that is not inkjet-recorded, and Gb indicates the 20-degree glossiness according to JIS-Z8741 of the recording surface that is inkjet-recorded with black dye ink. )
It is preferable that the 20-degree glossiness of the recording surface further satisfies the following formula (3).
G ≧ 28% (3)
Two or more coating layers are formed, and the coating layer constituting the recording surface preferably contains colloidal silica having an average particle diameter of 100 nm or less.
The innermost layer of the coating layer preferably contains amorphous silica having an average particle size of 1 μm or less.

  According to the present invention, it is possible to provide an ink jet recording material capable of obtaining an excellent image quality close to a silver salt photograph.

The present invention will be described in detail below.
The ink jet recording body of the present invention is provided with a low air-permeable or non-air-permeable support, and a recording surface is formed by providing a coating layer on at least one surface of the support, The 20-degree glossiness of the recording surface satisfies the following formulas (1) and (2). That is, the recording surface is the outermost surface of the coating layer and the surface on which ink jet recording is performed.
G ≧ 20% (1)
1.3 ≧ Gb / G ≧ 0.9 (2)

In the formula, G indicates the 20-degree glossiness according to JIS-Z8741 of the recording surface, and Gb indicates the 20-degree glossiness according to JIS-Z8741 of the recording surface when ink jet recording is performed on the recording surface with black dye ink.
That is, satisfying the formulas (1) and (2) means that the 20-degree glossiness G of the recording surface on which ink-jet recording is not performed is 20% or more, and the 20-degree glossiness G and the black dye ink are used for inkjet recording. It indicates that the ratio (Gb / G) of the recorded recording surface to the 20-degree glossiness Gb is 0.9 to 1.3. Hereinafter, the recording surface of the portion that is not inkjet-recorded may be referred to as a non-printing portion, and the recording surface of the portion that is inkjet-recorded with black dye ink may be referred to as a printing portion.

According to the ink jet recording material satisfying the formulas (1) and (2), an excellent image quality with glossiness close to a silver salt photograph can be formed. An inkjet recording material having a 20-degree glossiness G not satisfying the formula (1) is insufficient in glossiness, and the degree thereof is inferior to that of a silver salt photograph. In addition, in an inkjet recording material in which the 20-degree glossiness G and Gb do not satisfy the formula (2), the glossiness of the formed image quality is uneven, and the overall glossiness is uniform like a silver salt photograph. Is not exhibited, and glossiness is inferior.
Further, the 20-degree glossiness G of the recording surface is preferably in the range of the following formula (3).
G ≧ 28% (3)

  The 20 degree glossiness of the printed part is 23 ° C. and 50% relative humidity on the recording surface using a dye ink printer (trade name: PM-G800, EPSON photographic paper mode) manufactured by Seiko Epson. It refers to the value measured for a solid black print and then stored for 24 hours in an environment of 23 ° C. and 50% relative humidity. As the black dye, ICBK32 black ink (cartridge) manufactured by Seiko Epson Corporation can be preferably used.

  The ink jet recording material satisfying the formulas (1) and (2) is obtained by appropriately selecting and combining various conditions such as the support material, the composition and material of the coating layer, and the coating conditions of the coating layer. Can be manufactured.

The support used in the ink jet recording material of the present invention is not limited as long as it has low air permeability or non-air permeability. For example, resins such as polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, and polyester Paper base such as film (including synthetic paper), metal film, fine paper, art paper, coated paper, cast coated paper, foil paper, kraft paper, impregnated paper, vapor-deposited paper, water-soluble paper Examples thereof include resin-coated paper obtained by laminating a thermoplastic resin such as polyolefin on a material or nonwoven fabric, and a laminated sheet obtained by bonding films or the like on paper or nonwoven fabric.
Among these, preferred supports include so-called synthetic paper represented by YUPO (trade name, manufactured by YUPO Corporation) obtained by stretching polypropylene and performing special processing, and polyolefin resin (preferably polyethylene) Resin-coated paper laminated with (resin).

In the present invention, the low-permeable or non-permeable support means a support having an air permeability of 500 seconds or more. The air permeability of the support is preferably 1000 seconds or more. The air permeability is generally known as an item for evaluating the porosity of paper or nonwoven fabric. The air permeability is expressed as the time required for 100 ml of air to pass through a test piece having an area of 645 mm ² and is defined in JIS P 8117 (Paper and board air permeability test method).

Synthetic paper is obtained by extruding and biaxially stretching a polypropylene resin containing fine particles such as calcium carbonate, with a void formed in the interior, etc., and another layer laminated on this polypropylene resin film The laminated film made can be preferably used. More preferably, a synthetic paper in which a skin layer having no irregularities is formed on at least one surface of a polypropylene resin film. When using a synthetic paper having a skin layer formed in this manner, it is preferable to form a coating layer, which will be described later, on the skin layer side.
In addition, various layers such as an anchor layer, a primer layer, and an antistatic layer are formed on the surface of the synthetic paper in order to improve the coating suitability of the coating layer or to improve the chargeability. It may be used as a support.

  The resin-coated paper is preferably a paper base material laminated with a polyethylene resin kneaded with titanium oxide. When such a resin-coated paper is used, an ink jet recording body satisfying the above formulas (1) and (2) tends to be obtained. In this case, the thickness of the polyethylene resin layer is preferably 3 to 50 μm, and more preferably 5 to 40 μm. When the thickness of the polyethylene resin layer is 3 μm or more, defects such as holes in the polyethylene resin are less likely to occur at the time of resin coating, and the thickness can be easily controlled. On the other hand, if it is 50 μm or less, the cost of the resin-coated paper can be kept low. Moreover, in order to improve adhesiveness with the coating layer mentioned later, it is preferable to use as a support body, after giving the corona discharge treatment to the surface of resin-coated paper, or providing an anchor coat layer.

  Moreover, what was manufactured by using wood pulp as a main material is used for the paper base material used for resin-coated paper. As the wood pulp, various chemical pulps, mechanical pulps, regenerated pulps and the like can be used as appropriate, and these pulps can be adjusted in degree of beating by a beating machine in order to adjust paper strength, smoothness, papermaking suitability, and the like. The beating degree is not particularly limited, but generally about 250 to 550 mL (CSF: JIS P 8121) is a preferable range. Also, chlorine-free pulp such as so-called ECF and TCF pulp can be preferably used. In addition, a pigment can be added to the paper base as necessary. As the pigment, talc, calcium carbonate, clay, kaolin, calcined kaolin, silica, zeolite and the like are preferably used. Although the opacity and smoothness can be increased by the addition of the pigment, the paper strength may be reduced if it is added excessively, and the addition amount of the pigment is preferably about 1 to 20% by mass with respect to the wood pulp.

A coating layer is provided on at least one surface of the support described above.
At least one coating layer may be formed. However, when a plurality of layers are formed, an ink jet recording body satisfying the formulas (1) and (2) tends to be obtained. More preferably, an ink receiving layer for mainly receiving ink and a gloss layer for mainly expressing surface gloss are sequentially formed on the support to form a coating layer. When the coating layer has such a configuration, both the glossiness and ink absorbability of the ink jet recording material are extremely excellent, and an ink jet recording material satisfying the above formulas (1) and (2) can be obtained more easily. There is a tendency. Further, the ink receiving layer is mainly composed of a lower layer (hereinafter referred to as a solvent absorbing layer) that absorbs a solvent in the ink and an upper layer (hereinafter referred to as a dye fixing layer) that mainly fixes a colorant in the ink. A separate configuration is preferable because the color density of the ink jet recording material is further increased.

  Hereinafter, as a preferable configuration of the coating layer, an ink receiving layer and a gloss layer are sequentially formed from the support side, and the ink receiving layer further includes a solvent absorption layer on the support side and a dye fixing layer on the gloss layer side. A case is concretely illustrated and a coating layer is demonstrated. In the case of such a coating layer, the innermost layer of the coating layer refers to the solvent absorption layer, and the coating layer constituting the recording surface refers to the glossy layer. The construction of the construction layer is not limited in this way.

The ink receiving layer such as a solvent absorbing layer and a dye fixing layer usually contains fine particles and a binder, and further contains a crosslinking agent or a cationic compound as necessary.
As the fine particles used in the ink receiving layer, it is possible to give a high print density and high gloss to the ink jet recording body, and it tends to be easy to obtain an ink jet recording body satisfying the above formulas (1) and (2). It is preferable to use those having an average particle diameter of 1 μm or less.
The average particle diameter referred to in the present invention is a number average particle diameter, and in the case of secondary particles, it is a number average average secondary particle diameter. Specifically, regardless of whether the fine particles are powder or slurry, first, 200 g of a 3% fine particle aqueous dispersion is prepared, and then stirred and dispersed at 1000 rpm for 10 minutes with a commercially available homomixer. The particle diameter observed immediately with an electron microscope (SEM and TEM) (taken from 10,000 to 400,000 magnifications of an electron microscope, measured and averaged the diameter of a 5 cm square particle. “Handbook of fine particles” "See Asakura Shoten, p52, 1991).
In addition, the average particle diameter in the case of containing a plurality of types of fine particles refers to the average particle diameter of all the fine particles.

The average particle diameter of more preferable fine particles contained in the ink receiving layer is 800 nm or less, and more preferably 500 nm or less. When the fine particles are secondary particles, the preferred average primary particle size is about 3 to 50 nm. Ultrafine particles having an average particle diameter of 500 nm or less can be obtained by pulverizing and dispersing commercially available fine particles by mechanical means. The mechanical means include: ultrasonic homogenizer, pressure homogenizer, liquid collision type homogenizer, high-speed rotary mill, roller mill, container drive medium mill, medium agitation mill, jet mill, mortar, and crusher (coating in a bowl-shaped container). A device for grinding and kneading the pulverized material with a bowl-shaped stirring bar), a sand grinder, and the like.
The average pore diameter of the fine particles is not particularly limited, but is, for example, 20 nm or less, preferably 15 nm or less in terms of gloss and printing density.

  The types of fine particles include kaolin, clay, calcined clay, amorphous silica (also referred to as amorphous silica), zinc oxide, aluminum oxide, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate, alumina, colloidal silica, Zeolite, synthetic zeolite, sepiolite, smectite, synthetic smectite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment, hydrotalcite, urea resin plastic pigment, benzoguanamine plastic pigment, etc. Two or more species can be used.

Among the ink receiving layers, amorphous silica is preferably used for the solvent absorbing layer. When amorphous silica is used, an ink jet recording body satisfying the formulas (1) and (2) tends to be obtained, and this tendency is particularly large when an average particle diameter of 1 μm or less is used. Examples of the amorphous silica include wet method silica and gas phase method silica, but wet method silica produced by a gel method, a precipitation method or the like is particularly preferable.
The gel method wet process silica is produced, for example, as follows. First, silicate sol is produced by mixing sodium silicate and sulfuric acid using high-purity silica sand as a raw material. The silicic acid sol gradually polymerizes to form primary particles, and further, a three-dimensional aggregate is formed and gelled. This silica is micronized and pulverized. That is, in the gel method, reaction polymerization is performed on the acidic side, and the mixture is allowed to stand until it forms a gel (sorbet), washed with water and dried to obtain amorphous silica.
The wet method silica of the precipitation method is obtained by reaction polymerization on the alkali side, precipitation as it is, and drying. According to the gel method, amorphous silica having a small pore size between primary particles is obtained, and according to the precipitation method, amorphous silica having a large pore size between primary particles is obtained.
For the solvent absorption layer, wet method silica such as gel method and sedimentation method can be preferably used, but in particular, gel method amorphous silica is used in terms of ink absorbability of ink jet recording medium and heat and humidity resistance after printing. It is preferable. The reason for this is not necessarily clear, but it seems that the gel-based amorphous silica can quickly separate and absorb the solvent in the ink from the dye and has a high ability to retain the solvent in the pores.

Vapor phase silica is preferably used for the dye fixing layer of the ink receiving layer. By using vapor phase method silica, a high printing density and high gloss can be imparted to the ink jet recording material, and an ink jet recording material satisfying the formulas (1) and (2) tends to be obtained. In addition, a layer having a low haze value can be easily obtained.
In general, synthetic silica contains impurities such as metal ions in the raw material, and impurities are often mixed in the production process. Thus, the synthetic silica containing many impurities has a large refractive index and is inferior in transparency. However, in the gas phase method, the purity of silicon tetrachloride as a raw material can be made relatively high by distillation, and furthermore, silicon tetrachloride can be produced by combustion hydrolysis in the gas phase with a closed system, so that the production process Impurities can be prevented from being mixed in. Therefore, the obtained vapor phase method silica has high purity, and by using the vapor phase method silica, a layer having a low haze value and excellent transparency can be formed.
Although vapor phase silica is described in detail later, it is most preferable that it is treated with a cationic compound and blended in the form of cationic fine particles.

Other fine particles can be used in the dye-fixing layer depending on the purpose, such as adjustment of transparency and absorbency. Examples of such fine particles include colloids of wet-process silica produced by condensing mesoporous silica and active silicic acid. Examples thereof include alumina, alumina oxide and hydrated alumina, and these can be used alone or in combination.
However, in order to give a high print density and high gloss to the jet recording medium, the proportion of the vapor phase silica in the total fine particles of the dye fixing layer is preferably 50% by mass or more, and 80% by mass or more. More preferably, it is 100 mass%.

A water-soluble binder is preferably used as the binder usually contained in the ink receiving layer such as the solvent absorbing layer and the dye fixing layer.
As the water-soluble binder, polyvinyl alcohol (PVA) is preferable because the coating film strength is easily obtained. Furthermore, PVA having a degree of polymerization of 2000 or more and a saponification degree of 95 mol% or more is preferable from the balance between film formability and ink absorbability of the ink receiving layer, and more preferably PVA having a degree of polymerization of 4000 or more and a saponification degree of 98 mol% or more. is there.
As the water-soluble binder, a binder other than PVA can be used in combination as necessary. For example, PVA such as modified PVA such as cation-modified PVA and silyl-modified PVA, casein, soybean protein, synthetic proteins, starch, carboxymethyl cellulose, Cellulose derivatives such as methyl cellulose, or water-dispersible resins such as styrene-butadiene copolymer, conjugated diene polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, styrene-vinyl acetate copolymer In general, various known and publicly known adhesives in the field of coated paper, such as vinyl copolymer latex and the like. A temperature-sensitive polymer compound that exhibits hydrophilicity in a temperature range below the temperature-sensitive point and exhibits hydrophobicity in a temperature region higher than the temperature-sensitive point can also be used.

  The content of the binder in the ink receiving layer is preferably 5 parts by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more, with respect to 100 parts by mass of the fine particles in any of the solvent absorption layer and the dye fixing layer. 30 parts by mass or less, more preferably 5 parts by mass or more and 25 parts by mass or less. From the viewpoint of imparting ink absorptivity to the ink receiving layer, it is preferable to suppress the binder amount as much as possible because the pores formed between the fine particles are not reduced and the ink absorption rate can be increased. However, when the amount of the binder is small, when the coating liquid is applied to form the solvent absorption layer and the dye fixing layer, the layer is likely to crack. In that case, for example, after coating the coating liquid, the layer is thickened or gelled in the initial stage of drying, thereby preventing cracks in the coating layer due to hot air during drying.

  The method for thickening or gelling the layer is not particularly limited. For example, a method for thickening or gelling using a water-soluble binder blended with the coating liquid and a crosslinking agent capable of crosslinking reaction, energy such as electron beam, etc. To increase the viscosity or gel by supplying water, as a water-soluble binder, to use a thermosensitive polymer compound that exhibits hydrophilicity and hydrophobicity depending on the temperature conditions, and to increase the viscosity or gel by changing the temperature, etc. Is mentioned.

As a method of thickening or gelling using a crosslinking agent capable of crosslinking reaction with a water-soluble binder, the water-soluble binder exemplified above and a crosslinking agent capable of crosslinking reaction with the water-soluble binder are used in combination.
Specifically, a cross-linking agent is applied and impregnated in advance on the target surface, and then a coating solution is applied, a method in which a cross-linking agent is blended in the coating solution, a coating solution is applied to the target surface. Examples of the method include a method of applying a cross-linking agent after the process, and a method in which a cross-linking agent is applied and impregnated in advance is preferable because a coating layer with uniform thickening or gelation is easily obtained.

Examples of the crosslinking agent include boron compounds, epoxy compounds, glycidyl compounds, zirconium compounds, aluminum compounds, chromium compounds and the like. Among these, a boron compound is particularly preferable when it is combined with PVA because thickening or gelation occurs quickly. The boron compound is an oxygen acid having a boron atom as a central atom and a salt thereof.
Specific examples of the boron compound include orthoboric acid, metaboric acid, hypoboric acid, tetraboric acid, pentaboric acid, and sodium salts, potassium salts, and ammonium salts thereof. Among these, orthoboric acid and disodium tetraborate are preferable because the paint can be thickened appropriately. Although the usage-amount of a boron compound is based also on the kind of a boron compound and a water-soluble binder, it is preferable to use it in the ratio of 0.01-1.5 g / m < ² > on an object surface. When it is 1.5 g / m ² or less, the crosslinking density with the water-soluble binder does not become too high, and the layer can be prevented from being broken and broken or cracked, and when it is 0.01 g / m ² or more, Crosslinking is moderately strong and the gelation of the coating liquid is also moderate, and the layer is difficult to crack.

  As a specific method of thickening or gelling by supplying energy such as an electron beam, the following method is preferable. That is, as the binder, a water-soluble binder 1 that does not have a radical polymerizable unsaturated bond and forms a hydrogel by irradiating an aqueous solution with an electron beam is used with respect to 100 parts by mass of the fine particles. A coating liquid containing at a ratio of ˜100 parts by mass is applied, and then irradiated with an electron beam to hydrogel the applied coating liquid, and then dried to form a layer.

Examples of the water-soluble binder that does not have a radical polymerizable unsaturated bond and forms a hydrogel by irradiating an aqueous solution with an electron beam include PVA, polyethylene oxide, polyalkylene oxide, polyvinyl pyrrolidone, and water-soluble polyvinyl. Acetal, poly-N-vinylacetamide, polyacrylamide, polyacryloylmorpholine, polyhydroxyalkyl acrylate, polyacrylic acid, hydroxyethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose, gelatin, casein, and water-soluble derivatives thereof, and These copolymers can be exemplified, and one or more of these can be used.
As the electron beam irradiation method, for example, a scanning method, a curtain beam method, a broad beam method, or the like is adopted, and an acceleration voltage at the time of irradiation with an electron beam is appropriately about 50 to 300 kV. The amount of electron beam irradiation is preferably adjusted in the range of about 1 to 200 kGy. If it is 1 kGy or more, it is sufficient to cause the layer to gel, and if it is 200 kGy or less, the target surface or layer is hardly deteriorated or discolored.

As a water-soluble binder, a thermosensitive polymer compound that exhibits hydrophilicity and hydrophobicity depending on temperature conditions is used, and in a method of thickening or gelling by changing the temperature, the binder is used in a temperature range below the temperature sensitive point. A temperature-sensitive polymer compound that exhibits hydrophilicity and exhibits hydrophobicity in a temperature range higher than the temperature-sensitive point may be used. When this temperature-sensitive polymer compound is used, coating is performed at a temperature equal to or higher than the temperature-sensitive point, and cooling is performed below the temperature-sensitive point, whereby the applied layer is thickened or gelled. Thereafter, the ink receiving layer can be formed without causing cracks by drying.
Examples of such temperature-sensitive polymer compounds include those disclosed in JP-A No. 2003-40916, which are obtained by polymerization in the presence of PVA and / or PVA derivatives.

The ink-receiving layer may contain a cationic compound for the purpose of improving the fixing property of ink that is generally anionic. The cationic compound may be included in both the solvent absorbing layer and the dye fixing layer in the ink receiving layer. However, in view of the above-described purpose, the solvent absorbing layer substantially does not contain the cationic compound. A constitution in which the dye fixing layer contains a cationic compound is preferable. With such a configuration, the dye can be efficiently held in the transparent dye fixing layer, and a high print density can be imparted to the ink jet recording medium.
The phrase “substantially does not contain a cationic compound” means not only when it does not completely contain, but also when there is no intentional addition of a cationic compound in an amount sufficient to fix the pigment component of the ink. Including. For example, when a small amount of a cationic surfactant or the like is added as an auxiliary agent, or when a part of the cationic compound added to the dye fixing layer or other intermediate layer is transferred to the solvent absorption layer The solvent absorption layer shall be “substantially free of cationic compounds”.

Examples of the cationic compound include 1) polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, 2) acrylic polymers having secondary amino groups, tertiary amino groups, and quaternary ammonium groups, 3) Polyvinylamine and polyvinylamidines, 4) Dicyan cationic compounds represented by dicyandiamide / formalin copolymer, 5) Polyamine cationic compounds represented by dicyandiamide / polyethyleneamine copolymer, 6) Epichlorohydrin / dimethylamine copolymer, 7) diallyldimethylammonium -SO ₂ double condensate, 8) diallylamine salt · SO ₂ double condensate, 9) diallyldimethyl ammonium chloride polymers, 10) diallyldimethyl ammonium chloride Acrylamide copolymer, 11) Copolymer of allylamine salt, 12) Dialkylaminoethyl (meth) acrylate quaternary salt copolymer, 13) Acrylamide-diallylamine copolymer, 14) Cationic having 5-membered ring amidine structure Examples include known cationic compounds such as resins.

When the cationic compound is blended together with the fine particles, particularly when the fine particles are fine silica, the fine silica is generally anionic, and thus the fine silica particles may be aggregated during mixing. In this case, in order to suppress the aggregation of the fine silica particles and to obtain a predetermined particle diameter, the following two methods can be mentioned.
That is, a cationic compound is mixed and dispersed in commercially available amorphous silica (having a secondary particle size of several microns), and then this is pulverized into fine particles by applying a strong force by mechanical means. Or a method in which a cationic compound is mixed with a finely divided silica secondary particle dispersion, once thickened and aggregated, and then mechanically dispersed and pulverized again.
The fine particles treated in this way have a structure in which a cationic compound is partly bonded, and it is a slurry that is stably dispersed, or it is difficult to agglomerate even if an additional cationic compound is added. Have In the present invention, fine particles treated with such a cationic compound are referred to as cationic fine particles and can be suitably used.

As the mechanical means for dispersion or pulverization used in the production of the cationic fine particles, the means exemplified above such as an ultrasonic homogenizer can be used. If the desired particle size exceeds the average secondary particle size of 1000 nm, it can be sufficiently dispersed if treated with a weak mechanical force such as a homomixer. It is effective to add, and a pressure type dispersion method is preferable.
The pressure-type dispersion method is a method in which a slurry mixture of raw material particles is continuously passed through an orifice at a high pressure and pulverized at a high pressure, and the treatment pressure is 19.6 × 10 ^{6 to} 343.2 × 10 ⁶ Pa ( 200 to 3500 kgf / cm ² ), more preferably 49.0 × 10 ^{6 to} 245.3 × 10 ⁶ Pa (500 to 2500 kgf / cm ² ), and still more preferably 98.1 × 10 ^{6 to} 196.2 × 10. ⁶ Pa (1000 to 2000 kgf / cm ² ). Good dispersion or pulverization can be achieved by the above high-pressure pulverization. Further, it is more preferable to select a dispersion or pulverization method by causing the slurry-like mixture that has passed through the orifice at high pressure to collide oppositely. In the method of opposing collision, the dispersion is pressurized and guided to the inlet side, the dispersion is branched into two passages, and the flow path is narrowed by an orifice to accelerate the flow velocity and collide the particles by colliding with each other. Crush. As a material constituting the portion where the dispersion is accelerated or collided, diamond is preferably used for the reason of suppressing wear of the material.
As the high-pressure pulverizer, a pressure type homogenizer, an ultrasonic homogenizer, a microfluidizer, and a nanomizer are used. In particular, a microfluidizer and a nanomizer are preferable as the high-speed collision type homogenizer. The cationic fine particles thus treated are generally obtained as an aqueous dispersion (slurry or colloidal particles) having a solid content concentration of about 5 to 20% by mass.

  It does not specifically limit as a cationic compound used for a cationic fine particle, What was already illustrated can be used suitably. Among them, preferable cationic compounds include diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride-acrylamide copolymer, hydrochloride of acrylamide / diallylamine copolymer, dicyandiamide-polyethyleneamine copolymer, and 5-membered ring amidine structure. And at least one selected from the group consisting of a cationic resin. When this is used, the ink jet recording material is excellent in color developability, less blurring, and an excellent image is easily obtained.

  When manufacturing cationic fine particles, it is preferable to mix them in a ratio of 1 to 30 parts by mass of the cationic compound with respect to 100 parts by mass of the fine particles, and more preferably 3 to 20 parts by mass. When the cationic compound is 1 part by mass or more, the printing density of the ink jet recording body is easily improved, and when it is 30 parts by mass or less, the ink absorbency due to the extra cationic compound closing the voids between the fine particles. There is no decrease in image quality, and image blurring and unevenness are less likely to occur.

The ink receiving layer described above is formed using various known coating apparatuses such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a die coater, a curtain coater, and a slide bead coater. It can be formed by coating on the target surface and drying. That is, preferably, a solvent absorption layer is formed on a support and a dye fixing layer is formed thereon. Thereafter, calendar processing or the like may be performed as necessary.
Further, an aqueous solution of a boron compound such as borax may be applied between the solvent absorbing layer and the dye fixing layer, if necessary.

It is effective to provide a glossy layer on the ink receiving layer in order to improve glossiness, and to form a recording surface using this as the outermost layer of the coating layer.
The gloss layer usually contains fine particles. The fine particles are not particularly limited, but it is preferable to use inorganic fine particles such as colloidal silica, gas phase method silica, and alumina oxide because excellent gloss is exhibited. Furthermore, it is preferable to use a colloidal material, and particularly when colloidal silica is used, an ink jet recording body satisfying the formulas (1) and (2) can be easily obtained. In addition, the dispersion form at that time may be a monodispersion or an aggregated particle dispersion, but can impart a high printing density and high glossiness, and satisfies the formulas (1) and (2). Since it is easy to obtain an ink jet recording material, a monodisperse or an aggregated particle dispersion having a small particle diameter is mainly preferably used.
The average particle diameter of the fine particles is preferably 1 μm or less, more preferably 3 to 100 nm for primary particles and 700 nm or less for secondary particles. Most preferably, colloidal silica having an average particle size of 100 nm or less is used.

Among them, the colloidal silica particles preferably have a uniform particle size. In particular, the coefficient of variation (CV value) represented by the following formula is preferably 15% or less.
CV = (σ / D) × 100 [%]
In the above formula, σ is standard deviation, D is average particle diameter. Further, the individual silica particles are monodispersed, and the ratio of the aggregated particles is preferably 10% or less of the total number of particles.

  The glossy layer formed in this way is mainly intended for glossiness and does not necessarily require a dye fixing function. However, if necessary, cationic fine particles can be selected as fine particles to impart ink suitability. May be. As such a material, cation-modified colloidal silica, gas phase method silica, or alumina oxide is preferable. Among the alumina oxides, gas phase method (fumed) alumina oxide is preferable.

  The gloss layer may appropriately contain the same kind of binder as that used in the ink receiving layer as long as the ink absorbability is not impaired. Moreover, the above-mentioned cationic compound can also be added as needed.

As a method for forming the glossy layer, after applying the coating liquid for forming the glossy layer to the target surface, the coated coating liquid is pressed against a heated mirror drum while the coating liquid is in a wet state. Then, a so-called casting method of drying is preferable. In that case, a general commercially available release agent may be appropriately added to the gloss layer in order to facilitate the peeling of the gloss layer from the mirror drum.
Examples of mold releasing agents include fatty acids such as stearic acid, oleic acid, and palmitic acid, and salts thereof such as sodium, potassium, calcium, zinc, and ammonium, stearic acid amide, ethylenebisstearic acid amide, and methylenebisstearic acid amide. Fatty acid amides such as, aliphatic hydrocarbons such as microcrystalline wax, paraffin wax and polyethylene wax, higher alcohols such as cetyl alcohol and stearyl alcohol, fats and oils such as funnel oil and lecithin, lipids, fluorine-containing surface activity Examples thereof include various surfactants such as agents, and fluorine-based polymers such as tetrafluoroethylene polymer and ethylene-tetrafluoroethylene polymer.
Of these, aliphatic hydrocarbons or derivatives or modified products thereof, fatty acids or salts thereof, and lipids are particularly preferable. Among them, polyethylene wax is used as the aliphatic hydrocarbon, stearic acid or oleic acid is used as the fatty acid, and lipids are used. More preferably, lecithin is used.
Moreover, the addition amount of a mold release agent is 0.5-10 mass parts with respect to 100 mass parts of microparticles | fine-particles in a glossy layer.

In the present invention, since a support having low air permeability or non-air permeability is used as the support, in the casting method, in particular, immediately after application of the coating liquid, or while applying, pressure bonding with a mirror drum is performed. (For example, nip as disclosed in International Publication No. WO 03/039881.) In the subsequent steps, it is preferable to dry using a drying device as appropriate.
In order to produce an ink jet recording material satisfying the formulas (1) and (2), the material of the support, the structure and material of each coating layer, and the coating conditions of the coating layer are appropriately determined. It can be manufactured by combining, but especially when forming a glossy layer, the concentration and coating amount of the coating liquid for forming the glossy layer, the type and particle size of fine particles used in the glossy layer, and in the case of the casting method In this case, a combination of conditions such as the temperature of the mirror drum and the pressure (nip pressure) during pressure bonding is important.

As another method for forming the glossy layer, a transfer film having a glossy layer formed on the surface of a substrate such as a PET film was prepared and formed on a support so that the glossy layer side was in contact therewith. Prepare a transfer film in which a glossy layer and an ink receiving layer are formed on the surface of the base material, and a method of peeling the base material after bonding to the ink receiving layer and then supporting the ink receiving layer side. And a method of peeling the base material.
When forming a glossy layer by a method using a base material in this way, in addition to the concentration and coating amount of the coating liquid for forming the glossy layer, the type and particle size of the fine particles used in the glossy layer, A combination of conditions such as pressure (nip pressure) is important.

Solid coating amount of the glossy layer is in any case of the method using a casting method and the transfer film is preferably in the range of 0.1 to 10 g / ^{m 2,} more preferably 0.2-5 g / ^{m 2} 0.5-2 g / m ² is more preferable. Within such a range, the thickness of the coating film becomes appropriate, interference color due to light does not easily occur, and the ink absorption rate does not easily decrease.

  As described above, the ink jet recording body is provided with a low-air-permeable or non-air-permeable support, and a recording layer is formed by providing a coating layer on at least one surface of the support. In the case of an image, if the 20-degree glossiness of the recording surface satisfies the expressions (1) and (2), an excellent image quality close to a silver salt photograph can be formed. Although the reason why the 20-degree glossiness of the recording surface has a great influence on the image quality to be formed is not clear, the angle of the line of sight with respect to the printed matter when a person stares at the printed matter. This is considered to be due to the fact that it almost coincides with the measurement angle of 20 degree glossiness.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Further, “parts” and “%” in the examples are solid contents excluding water unless otherwise specified, and indicate “parts by mass” and “% by mass”, respectively. Even when pulverized and dispersed, the primary particle size does not change.

[Support]
(Support 1)
1. Base paper Coniferous bleached kraft pulp (NBKP) beaten to 250 ml of Canadian standard freeness (JIS P8121) and hardwood bleached kraft pulp (LBKP) beaten to Canadian standard freeness of 280 ml 2: 8 Was mixed to prepare a pulp slurry having a concentration of 0.5%. To this pulp slurry, 2.0% cationized starch, 0.4% alkyl ketene dimer, 0.1% anionized polyacrylamide resin and 0.7% polyamide polyamine epichlorohydrin resin are added to the pulp dry mass, Stirred and dispersed. The pulp slurry having the above composition was made with a long net machine and passed through a dryer, a size press, and a machine calendar to produce a base paper having a basis weight of 180 g / m ² and a tenacity of 1.0 g / cm ³ . The size press solution used in the size press step was prepared by mixing carboxyl-modified PVA and sodium chloride at a mass ratio of 2: 1, adding this to water and dissolving it by heating to a concentration of 5%. A size press solution was applied in a total of 25 cc on both sides of the paper to obtain a base paper.

2. Polyolefin resin composition 1
35 parts by mass of long-chain low-density polyethylene resin (density 0.926 g / cm ³ , melt index 20 g / 10 min), 50 parts by mass of low-density polyethylene resin (density 0.919 g / cm ³ , melt index 2 g / 10 min) , 15 parts by mass of anatase-type titanium dioxide (Ishihara Sangyo Co., Ltd., trade name: A-220), 0.1 parts by mass of zinc stearate, 0.03 parts by mass of antioxidant (manufactured by Ciba Geigy, trade name: Irganox 1010), Ultramarine (Daiichi Kasei Co., Ltd., trade name: Aoguchi Ultramarine No. 2000) 0.09 parts by mass, fluorescent whitening agent (Ciba Geigy, trade name: UVITEX OB) 0.3 parts by mass are mixed with a Banbury mixer. Dispersed to obtain polyolefin resin composition 1.

3. Polyolefin resin composition 2
65 parts by mass of high density polyethylene resin (density 0.954 g / cm ³ , melt index 20 g / 10 min) and 35 parts by mass of low density polyethylene resin (density 0.924 g / cm ³ , melt index 4 g / 10 min) A polyolefin resin composition 2 was obtained by mixing and dispersing with a mixer.

4). Preparation of non-air permeable support After corona discharge treatment on both sides of the base paper, the polyolefin resin composition 1 is applied to the felt side of the base paper so that the coating amount is 27 g / m ^2, and the polyolefin resin. The composition 2 (resin composition for the back surface) was applied to the wire surface side of the base paper with a melt extruder (melting temperature of 320 ° C.) having a T-shaped die so that the coating amount was 30 g / m ² . The felt side of the base paper is cooled and solidified with a mirror-like cooling roll, and the wire side is cooled and solidified. The smoothness (Oken type, J.TAPPI No. 5) is 6000 seconds, and the opacity (JIS P8138) is A 93% resin-coated support 1 was produced.
The air permeability of this support according to JIS P 8117 (paper and paperboard air permeability test method) was 1000 seconds or more. The layer made of polyolefin resin composition 1 formed on the support has a thickness of 32 μm, and the layer made of polyolefin resin composition 2 has a thickness of 35 μm.

[Silica sol for coating liquid]
(Silica sol A)
A 20% aqueous dispersion of gel silica (produced by Grace Devison, trade name: Silojet 703A, average primary particle size: 12 nm, average secondary particle size: about 300 nm) is prepared, and silica sol A, which is a silica sol of a wet method It was.

(Silica sol B)
After commercially dispersing fumed silica (manufactured by Tokuyama Co., Ltd., trade name, Leolosil QS-30, specific surface area 300 m ² / g, average primary particle size: about 10 nm, gas phase method silica) by water dispersion and grinding with a sand grinder, The pulverization and dispersion were repeated using a nanomizer (trade name: Nanomizer, manufactured by Yoshida Kikai Kogyo Co., Ltd.) to prepare a 10% dispersion having an average secondary particle size of 80 nm after classification. 15 parts of diallyldimethyl quaternary ammonium hydrochloride (manufactured by Senka Co., Ltd., trade name: Unisense CP-103) as a cationic resin was added to the dispersion to cause pigment aggregation and dispersion thickening. Again, pulverization and dispersion were repeated using a nanomizer to prepare an 8% dispersion (silica sol B) having an average secondary particle diameter (aggregated particle diameter) of 250 nm.

(Silica sol C)
Anionic colloidal silica (manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex OL, average primary particle size: 40 to 50 nm) 20% aqueous dispersion was prepared to obtain silica sol B which is an anionic colloidal silica sol.

[Example 1]
The following coating liquid A was applied to the support 1 with a die coater so that the coating amount was 12 g / m ^2, and a solvent absorption layer was formed. Next, a 3.0% borax aqueous solution was applied onto the solvent absorption layer so that the coating amount was 0.60 g / m ² . Further, the coating liquid B was applied and dried under the conditions of Wet on Wet so that the coating amount was 15 g / m ² to form a dye fixing layer. Thereafter, the coating liquid C is applied onto the dye fixing layer so as to have a coating amount of 0.5 g / m ^2, and is pressed against a mirror drum having a surface temperature of 95 ° C. while being wet (nip pressure). : 8.8 MPa), and after that, a glossy layer was formed through a drying process to obtain an ink jet recording material.
Various evaluations to be described later were performed on the obtained ink jet recording material.
(Coating fluid A)
To 100 parts of silica sol A, 20 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-140) and 1 part of fluorescent whitening agent (manufactured by Sumitomo Chemical Co., Ltd., Whitex BPS) were mixed to prepare a solution having a concentration of 15%.
(Coating fluid B)
18 parts of PVA (trade name: PVA-135, manufactured by Kuraray Co., Ltd.) was mixed with 100 parts of silica sol B to prepare a liquid having a concentration of 8%.
(Coating fluid C)
100 parts of silica sol C and 2 parts of ammonium oleate as a release agent were mixed to prepare a 3% dispersion.

[Example 2]
The support 1 was coated and dried with a die coater so that the coating amount A was 20 g / m ² to form a solvent absorption layer. Next, a 0.7% borax aqueous solution was applied onto the solvent absorption layer with a bar coater so that the coating amount was 0.2 g / m ² . Further, the coating liquid B was applied and dried under the conditions of Wet on Wet so that the coating amount was 7 g / m ² to form a dye fixing layer. Thereafter, the coating liquid C is applied onto the dye fixing layer so as to have a coating amount of 1.0 g / m ^2, and is pressed against a mirror drum having a surface temperature of 95 ° C. while being wet (nip pressure). : 8.8 MPa), and after that, a glossy layer was formed through a drying process to obtain an ink jet recording material. Various evaluations were performed on the obtained ink jet recording material in the same manner as in Example 1.

[Comparative Example 1]
An ink jet recording material was obtained in the same manner as in Example 1 except that the surface temperature of the mirror drum was set to 75 ° C., and various evaluations were performed in the same manner as in Example 1.

[Comparative Example 2]
An ink jet recording material was obtained in the same manner as in Example 1 except that the concentration 3% of the coating liquid C was changed to 12%, and various evaluations were performed in the same manner as in Example 1.

[Comparative Example 3]
An ink jet recording material was obtained in the same manner as in Example 1 except that the nip pressure was set at 8.8 MPa, and various evaluations were performed in the same manner as in Example 1.

[Comparative Example 4]
Various evaluations were performed in the same manner as in Example 1 for a Canon glossy paper (manufactured by Canon Inc.), which is a commercially available glossy inkjet recording paper.

[Comparative Example 5]
Various evaluations were performed in the same manner as in Example 1 with respect to Canon Super Photo Paper (manufactured by Canon Inc.), which is a commercially available glossy inkjet recording paper.

[Comparative Example 6]
Various evaluations were performed in the same manner as in Example 1 on a commercially available glossy inkjet recording paper, Seiko Epson Photographic Paper (Glossy) (manufactured by Seiko Epson).

[Comparative Example 7]
Various evaluations were performed in the same manner as in Example 1 for a commercially available glossy inkjet recording paper, Konica Minolta QP Probox (manufactured by Konica Minolta).

[Comparative Example 8]
Various evaluations were carried out in the same manner as in Example 1 on a commercially available glossy ink jet recording paper, a photofinishing (glossy) (made by Fuji Photo Film Co., Ltd.).

[Comparative Example 9]
Various evaluations were performed in the same manner as in Example 1 on a commercially available glossy inkjet recording paper, Kodak Professional Photo Paper (manufactured by Kodak).

[Example 3]
A mixed solution of 100 parts of acidic anion colloidal silica (trade name: Snowtex ST-OL, manufactured by Nissan Chemical Industries, Ltd.) having an average particle size of 45 nm and 30 parts of silicon-containing modified PVA (trade name: R-2105, manufactured by Kuraray Co., Ltd.) Prepared and coated on the surface of a PET film (Toray Industries, 75 μ, product name: Lumira-T, surface roughness Ra = 0.02 μm) with a Mayer bar so that the coating amount is 5 g / m ^2. A layer to become a glossy layer was formed. Next, a 2.0% borax aqueous solution was applied onto the layer formed in this manner with a bar coater so that the coating amount was 0.4 g / m ^2, and then the coating solution B was added onto this layer by Daiko. The coating was dried under wet-on-wet conditions so that the coating amount was 10 g / m ² , thereby forming a layer serving as a dye fixing layer.
On the other hand, the coating liquid A was coated on the support 1 with a die coater so that the coating amount was 8 g / m ² to form a layer serving as a solvent absorption layer.
And it bonded together so that the layer used as a pigment | dye fixing layer and the layer used as a solvent absorption layer might face, and carried out cooling pressure bonding with the cooling roll. Subsequently, the PET film is peeled off and dried so that the water content of the coating layer becomes 6.0% / m ² , and the solvent absorbing layer formed from the coating solution A on the support 1, the coating solution An ink jet recording body comprising a dye fixing layer and a gloss layer formed from B was produced.
Various evaluations were performed on the obtained ink jet recording material in the same manner as in Example 1.

[Example 4]
In Example 2, an ink jet recording material was obtained in the same manner as in Example 2 except that the coating liquid D shown below was used instead of the coating liquid C.
(Coating fluid D)
Silica sol D and dioleyldimethylammonium chloride as a release agent were mixed at a solid content ratio of 100: 2, and the coating solution concentration was adjusted to 3%.
(Silica sol D)
Silica sol D was a 20% aqueous dispersion of cationic colloidal silica (manufactured by Nissan Chemical Industries, trade name: Snowtex AKL, average particle size: 40-50 nm).

[Example 5]
In Example 2, an ink jet recording material was obtained in the same manner as in Example 2 except that the coating liquid E shown below was used instead of the coating liquid C.
(Coating fluid E)
Silica sol E and dioleyldimethylammonium chloride as a release agent were mixed at a solid content ratio of 100: 2, and the coating solution concentration was adjusted to 3%.
(Silica sol E)
The surface of monodispersed anionic colloidal silica having an average particle diameter of 45 nm was coated with polyaluminum chloride, and a 20% aqueous dispersion of colloidal silica having a cationic hydrated metal compound supported on the surface was used as silica sol E. The particle size distribution of the cationic colloidal silica had a coefficient of variation of 5%.

[Evaluation methods]
The glossiness of the non-printed part and the printed part, the glossiness of the image, the print density, and the ink absorbability (whether there is no unevenness or no uniformity) were evaluated by the following methods.
For printing in each evaluation, a dye ink printer (trade name: PM-G800, EPSON photographic paper mode) manufactured by Seiko Epson Corporation was used.

(Measurement of 20 ° glossiness)
Based on JIS-Z8741, the 20 ° glossiness of the non-printing part and the printing part was measured on the surface (recording surface) of the coating layer of the ink jet recording body, and the results were designated as G and Gb, respectively.
For the measurement of the 20 ° glossiness of the printed part, black solid printing was performed using a PM-G800 manufactured by Seiko Epson Corporation in an environment of 23 ° C. and a relative humidity of 50%, and the temperature was 23 ° C. and the relative humidity was 50%. What was preserve | saved under the environment for 24 hours was used. Further, as a black dye, ICBK32 black ink (cartridge) manufactured by Seiko Epson Corporation was used.

(Glossiness of the image)
Visual evaluation was performed from a lateral angle of 20 degrees with respect to the surface (recording surface) of the coating layer.
The image name “fruit basket” of “high-definition color digital standard image data (ISO / JIS-SCID), issued by Japanese Standards Association (Foundation)” is used as an evaluation image, and the evaluation model is the PM-G800 printer. The abbreviations in the table indicate the following contents.
A: Excellent glossiness comparable to that of a silver salt photograph.
○: Inferior to silver halide photographs, but glossy.
Δ: Slightly dull gloss.
X: Matte tone.

(Print density)
The print density was measured with a Gretag Macbeth reflection densitometer (RD-19I, manufactured by Gretag Macbeth Co., Ltd.), which was black-printed with the PM-G800 printer and stored for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%. It is the value. The numbers shown in the table are average values of five measurements.

(Ink absorbency (solid uniformity))
Ink absorptivity was evaluated using a Canon ink dye ink printer (trade name: PIXUS iP4100, super photo paper mode). The evaluation was performed by performing green solid printing on the recording surface and visually observing the ink absorbency of the solid printing portion.
(Double-circle): The solid part has no unevenness and is in a good state.
◯: A level in which a slight unevenness is observed in the solid part but hardly causes a problem.
Δ: Some unevenness is observed in the solid part, which is a problem level depending on the use situation.

(Scraping of blank paper)
Using PIXUS iP4100 manufactured by Canon Inc., printing was performed in the C-type paper feeding mode, and the state of transport scratches on the surface of the inkjet recording medium was sensory evaluated.
(Double-circle): A conveyance flaw is not seen on the surface but it is in a favorable state.
○: A level of scars that hardly cause a problem, although some scratches on the surface are observed.
[Delta]: A level in which a lot of conveyance scratches are observed on the surface, which causes a problem depending on the use situation.

When an image was formed on the ink jet recording material of each example satisfying the formulas (1) and (2), the recording surface had an excellent gloss feeling similar to a silver salt photograph and good glossiness. Thus, it has been clarified that such an ink jet recording material can form an image quality excellent in that of a silver salt photograph. Further, according to the examples, the print density, ink absorbability, and white paper scratch resistance were also good.

Claims (4)

In an ink jet recording body in which a recording surface is formed by providing a coating layer on a low air-permeable or non-air-permeable support,
An ink jet recording material wherein the recording surface has a 20-degree glossiness satisfying the following formulas (1) and (2):
G ≧ 20% (1)
1.3 ≧ Gb / G ≧ 0.9 (2)
(In the formula, G indicates the 20-degree glossiness according to JIS-Z8741 of the recording surface that is not inkjet-recorded, and Gb indicates the 20-degree glossiness according to JIS-Z8741 of the recording surface that is inkjet-recorded with black dye ink. ) The inkjet recording body according to claim 1, wherein the 20-degree glossiness of the recording surface further satisfies the following formula (3).
G ≧ 28% (3) Two or more coating layers are formed,
The inkjet recording material according to claim 1 or 2, wherein the coating layer constituting the recording surface contains colloidal silica having an average particle diameter of 100 nm or less. 4. The ink jet recording material according to claim 3, wherein the innermost layer of the coating layer contains amorphous silica having an average particle diameter of 1 [mu] m or less.