JP4162149B2 - Glossy paper for inkjet recording - Google Patents

Description

  The present invention relates to a glossy paper for ink-jet recording, which has a glossiness as high as that of a silver salt photograph, has excellent abrasion resistance on a glossy surface, and has a print quality as high as photographic image quality.

The ink jet recording method is a method of recording by forming dots by ejecting ink droplets and attaching them onto recording paper. In recent years, recording with high print quality has become possible due to technological advances in inkjet printers, inks, and recording media. As an element required for an inkjet recording medium,
(A) The ink absorbency and drying are high,
(B) high print density;
(C) There are no dot spread and whiskers. If ordinary plain paper has a certain size or more, it can be expected to have a certain level of print quality with little blurring. On the other hand, when a higher print quality is required, a dedicated medium in which an ink receiving layer suitable for the ink of an ink jet printer is provided on various media on the medium is used. Many of these ink-jet recording media use paper or film as a support and a pigment coating layer mainly composed of pigment and binder or a resin coating layer not containing pigment on the surface. Is done.

The ink jet dedicated medium is further classified into a matte medium and a glossy medium from the surface state. The latter glossy medium is used when image quality closer to silver halide photography is required. As characteristics required for these glossy media, in addition to the characteristics described above,
(D) the roundness of the dots is high and the image reproducibility is good,
(E) good water resistance and light resistance;
(F) The glossiness of the image area and the white paper portion is high.

  As a method for producing a glossy medium, various methods have been proposed in order to maintain the characteristics (b) to (f) while maintaining the ink absorbability and drying property of (a). As a general method, there are a method of forming an ink receiving layer by a cast coating method to give gloss to the surface and a method of forming an ink receiving layer on a photographic paper base.

  In general, the former is easier to control the ink absorptivity of (a) than the latter, but (d) dot roundness, image reproducibility, (f) glossiness and quality of image area and blank paper portion. Inferior to the latter. When the ink-receiving layer is formed on the surface of the photographic paper base, since the polyethylene film layer is formed on the paper base as generally called RC paper (resin-coated paper), the film surface Is smooth, the surface of the ink receiving layer is also smooth, and a glossy surface is easily formed.

  However, it is necessary to increase the coating amount in order to increase the ink absorbency, and since the base material itself is more expensive than paper, the overall cost is higher than that of the former glossy medium by the cast coating method. ing. In addition, when it is discarded, there is also a problem that it cannot be recycled because it is a composite material.

  Conventional glossy paper for ink-jet recording by the cast coating method is advantageous in this respect, but has the above-mentioned problems in quality, and various proposals have been made to solve these problems.

  For example, there is a proposal that an inkjet recording paper having high surface smoothness and excellent image quality can be obtained by defining the average roughness, glossiness and air permeability of the recording paper on the surface of the recording layer (for example, , See Patent Document 1).

  There is also a proposal that an ink jet recording sheet having excellent gloss and ink receptivity can be obtained by defining the size and number of cracks on the surface of the recording layer (see, for example, Patent Document 2).

  Furthermore, there is also a proposal of an ink jet recording sheet containing a pearl necklace-shaped colloidal silica (see, for example, Patent Document 3).

  In recent years, there has been proposed a recording sheet coated with a mixture of alumina hydrate and a water-soluble binder, which has a high ink absorption rate and a glossiness similar to that of a silver salt photograph (for example, Patent Document 4). See).

Japanese Patent Laid-Open No. 06-72017 JP-A-11-348416 JP 2000-108506 A Japanese Patent Laid-Open No. 06-055829

  However, the technique disclosed in Patent Document 2 has a problem that, when the number of cracks is too small, the glossiness increases, but the ink absorbability decreases. In addition, the technique disclosed in Patent Document 3 has a certain effect in improving print quality, particularly ink absorbability, by using pearl necklace-shaped colloidal silica, but surface strength and glossiness are always satisfactory. It has not reached. Furthermore, the technique disclosed in Patent Document 4 has a feature that the glossiness is very excellent, but has a drawback that the glossy surface is easily damaged because of the excellent glossiness. For example, when used for postcard applications, address printing is performed on the back side, but there is a drawback that scratches are easily caused by rubbing by the paper feed section guide and rubbing with the suction wheel of the paper ejection section during printing. In addition, there is a problem that a flaw easily occurs due to contact between the glossy surface and the paper feed roller during address printing with an inkjet printer. In any case, in conventional glossy paper for ink-jet recording such as Patent Documents 1 to 4 produced by the cast coating method, the image quality and uniform glossiness exceeding the media produced using the photographic paper substrate or film substrate. In the present situation, there is no recording medium having both excellent and scratch resistance.

  Therefore, the present invention has a high gloss feeling similar to that of a silver salt photograph while having good ink absorbability, and is excellent in scratch resistance of a glossy surface, and is produced using a photographic paper substrate or a film substrate. An object of the present invention is to provide a recyclable glossy paper for ink-jet recording which has an image quality comparable to that of a printed medium and a uniform glossiness.

The present inventors have found that the above-mentioned problem can be solved when the glossy layer contains at least one of θ-alumina or γ-alumina and alumina-modified silica as a pigment, and a zirconium compound. The present invention has been completed. That is, the ink jet recording glossy paper according to the present invention, at least one side one or more layers of the ink-receiving layer is provided in the paper substrate, glossy layer mainly composed of pigment and binder in the ink receiving layer And the gloss-expressing layer is formed by applying a coating liquid containing the pigment and the binder on the ink receiving layer to form a coating layer, and then heating the coating layer to a mirror surface It is formed by a cast coat method formed by pressure-bonding to a finished metal surface, and the gloss developing layer is alumina in which at least one of θ-alumina or γ-alumina and the surface of silica are modified with alumina. containing the modified silica as the pigment, and has containing zirconium compound, and theta-alumina or γ- alumina or BET specific surface area of both contained as the pigment Wherein the 50~220m is ² / g. At this time, the glossy paper for ink jet recording has the image clarity of the surface of the gloss developing layer (JIS H8866-2: 1999 “Image clarity test method of anodized film of aluminum and aluminum alloy—Part 2: Instrument measurement method”). 55% or more.

In the glossy paper for ink-jet recording according to the present invention, θ-alumina and / or γ-alumina contained as the pigment is contained in the glossy expression layer in a proportion of 50% by mass to 80% by mass of the pigment. Including cases where

  In the glossy paper for ink-jet recording according to the present invention, the glossy expression layer preferably contains any one of zirconium nitrate, zirconium acetate or hydroxyzirconium chloride as the zirconium compound, or a mixture of two or more thereof. . The surface strength of the glossy layer is improved, and the gloss resistance of the glossy paper for inkjet recording is more excellent.

In the glossy paper for ink jet recording according to the present invention, the content of the zirconium compound is 0.01 to 20 parts by mass in terms of ZrO _{2 with} respect to 100 parts by mass of the pigment contained in the glossy layer. preferable. It is possible to balance the scratch resistance and ink absorbability of the glossy paper for ink jet recording.

In the glossy paper for ink-jet recording according to the present invention, the content of the alumina that modifies the surface of the silica is preferably 1 × 10 ^{−4 to} 20% by mass with respect to the silica. The surface strength of the glossy layer is improved, and the gloss resistance of the glossy paper for inkjet recording is more excellent.

  In the glossy paper for ink-jet recording according to the present invention, it is preferable that the glossy layer further contains vapor-phase process silica as the pigment. The image sharpness and ink absorbability of the glossy paper for inkjet recording can be balanced at a high level.

  In the glossy paper for ink-jet recording according to the present invention, the glossy expression layer preferably contains silanol-modified polyvinyl alcohol as the binder. While the ink absorbability and glossiness of the glossy paper for ink jet recording are balanced at a high level, the cohesive strength becomes strong, so that the surface strength of the gloss developing layer is increased, and the scratch resistance of the glossy paper for ink jet recording is increased. Better.

  In the glossy paper for ink-jet recording according to the present invention, the glossy layer preferably contains a cationic acrylic resin as the binder. Since the cationic acrylic resin has high transparency, it is difficult to impair the transparency of the glossy expression layer, the image clarity becomes good, and the light resistance is excellent, so that the storage stability of the glossy paper for inkjet recording is hardly deteriorated. An effect is also obtained.

  In the glossy paper for inkjet recording according to the present invention, the cationic acrylic resin is preferably a cationic acrylic silicone resin. Since the cationic acrylic silicone resin is excellent in drum adhesion, the glossy paper for ink-jet recording has a high gloss feeling and is more excellent in scratch resistance.

  In the glossy paper for inkjet recording according to the present invention, the content of the binder in the glossy expression layer is 5 to 30 parts by mass with respect to 100 parts by mass of the pigment contained in the glossy expression layer. preferable. The image quality of the glossy paper for inkjet recording can be further improved.

  In the glossy paper for ink-jet recording according to the present invention, the glossy expression layer is preferably formed by the solidification method of the cast coat method and contains a boron compound as a coagulant. The glossy paper for ink jet recording can obtain a more uniform gloss feeling.

  As described above, the glossy paper for ink jet recording according to the present invention has a good color developability while balancing a very good glossiness, ink absorbability and scratch resistance at a high level. Since the glossy paper for inkjet recording according to the present invention uses paper as a base material, the manufacturing cost is lower than that of a photographic paper base material having a film layer, and when it is discarded, it can be recycled and effectively used resources. It is also preferable from the viewpoint.

  Hereinafter, the present invention will be described in detail, but the present invention is not construed as being limited to these descriptions.

Jet recording glossy paper according to the present embodiment, at least one side one or more layers of the ink-receiving layer is provided on the paper substrate, glossy layer mainly composed of pigment and binder in the ink-receiving layer is The gloss-developing layer is formed by applying a coating liquid containing the pigment and the binder onto the ink receiving layer to form a coating layer, and then heating the coating layer to a mirror finish Alumina modification in which at least one of [theta] -alumina or [gamma] -alumina and the surface of silica are modified with alumina are formed by a cast coat method formed by pressure-bonding to the metal surface of the silica was contained as the pigment, and has containing zirconium compound, and BET specific surface area of the θ- alumina or γ- alumina or both are contained as the pigment is 50 Wherein the 220m is ² / g. At this time, the glossy paper for ink jet recording has the image clarity of the surface of the gloss developing layer (JIS H8866-2: 1999 “Image clarity test method of anodized film of aluminum and aluminum alloy—Part 2: Instrument measurement method”). 55% or more.

(Structure of glossy layer)
Usually, it is common to use spherical colloidal silica as the pigment of the glossy layer of the glossy paper for inkjet recording by the cast coating method. Spherical colloidal silica tends to have high surface strength and therefore has high scratch resistance. However, since ink absorbency is relatively poor, it is very difficult to balance glossiness and ink absorbency at a high level. is there. Further, as a non-spherical colloidal silica, a necklace-shaped colloidal silica is known, but the ink absorbability is better than the spherical colloidal silica, but there are problems that the glossiness is inferior and the surface strength is weak.

  On the other hand, by using alumina as a pigment, it is possible to obtain glossy paper for ink-jet recording which is excellent in ink absorbability, excellent in color developability of dye ink and pigment ink, and excellent in gloss. However, as described above, it is easy to be scratched, and the scratch resistance is inferior to that of colloidal silica, so it is very difficult to maintain the print quality, glossiness and scratch resistance at a high level. It is. The glossy expression layer in the present embodiment contains at least one of θ-alumina or γ-alumina and alumina-modified silica whose silica surface is modified with alumina as a pigment, and contains a zirconium compound. It is a feature. Here, the glossy layer may contain both θ-alumina and γ-alumina as pigments. This makes it possible to maintain the print quality, glossiness, and scratch resistance at a high level.

The θ-alumina and / or γ-alumina used in the present embodiment is a fine particle, and the particle size is preferably 10 nm to 1 μm, and more preferably 50 nm to 500 nm. Preferably the BET specific surface area of the alumina is 50~220m ² / g, more preferably 55~150m ² / g. The abrasion resistance of the glossy surface of the glossy layer, the glossiness of the surface and the ink absorbability can be balanced at a higher level. When the BET specific surface area of alumina is less than 50 m ² / g, the scratch resistance is improved, but the ink absorbability tends to deteriorate. On the other hand, when the BET specific surface area of alumina exceeds 220 m ² / g, the ink absorbability is improved, but the scratch resistance may be deteriorated. In addition, when alumina having a crystal structure other than θ-alumina or γ-alumina is used, it is difficult to achieve both ink absorbability and abrasion resistance of the glossy surface.

  The θ-alumina or γ-alumina used in the present embodiment may be obtained by any method. Further, “θ and γ” of θ-alumina and γ-alumina mean crystal forms of alumina and can be determined by X-ray diffraction measurement.

Moreover, it is indispensable that the gloss expressing layer in this embodiment contains alumina-modified silica in which the silica surface is modified with alumina. The alumina-modified silica used in the present embodiment may be obtained by any method. In the glossy paper for ink-jet recording according to the present embodiment, by using at least one of θ-alumina or γ-alumina and alumina-modified silica, the surface strength of the glossy layer is increased, and the glossy surface The coefficient of friction decreases. By these effects, the abrasion resistance of the glossy surface is improved. In the glossy paper for ink jet recording according to the present embodiment, the content of alumina that modifies the surface of silica is preferably 1 × 10 ^{−4 to} 20% by mass with respect to silica, and 1 × 10 ^−2. More preferably, it is -5 mass%. In such a range, the above-described characteristics can be obtained more strongly.

  In addition, for the glossy layer in the present embodiment, at least one of θ-alumina and γ-alumina and alumina-modified silica may be appropriately selected and used. In the glossy paper for ink jet recording according to the present embodiment, it is preferable that the glossy expression layer further contains gas phase method silica as a pigment. The image clarity and ink absorbability of glossy paper for inkjet recording can be balanced at a high level. Examples of pigments other than the above include, for example, precipitated silica, gel silica, pseudoboehmite, α-alumina, β-alumina, σ-alumina, spherical colloidal silica, collar necklace colloidal silica, or a plurality of particles. There is colloidal silica having a shape that is randomly aggregated.

  In addition, it is indispensable that the gloss developing layer in this embodiment contains a zirconium compound. This zirconium compound serves as a crosslinking agent. When the glossy layer contains the zirconium compound, the bonding due to the crosslinking effect between the inorganic fine particles and the binder is strengthened, and the surface strength is improved.

  In the glossy paper for ink jet recording according to the present embodiment, the glossy expression layer preferably contains any one of zirconium nitrate, zirconium acetate, and hydroxyzirconium chloride as a zirconium compound, or a mixture of two or more thereof. The surface strength of the glossy layer is improved, and the gloss resistance of the glossy paper for ink jet recording according to this embodiment is more excellent. Moreover, the medicine which has these as a main component is also preferably used in this embodiment. Examples of zirconium compounds other than the above include, for example, ammonium zirconium carbonate, potassium zirconium carbonate, zirconium phosphate, sodium zirconium phosphate, zirconium sulfate or zirconium oxychloride, and one of these is used alone or two or more thereof are used. You may use together.

In the glossy paper for ink jet recording according to the present embodiment, the content of the zirconium compound is preferably 0.01 to 20 parts by mass in terms of ZrO _{2 with} respect to 100 parts by mass of the pigment contained in the glossy layer. It is more preferable that it is 0.1-5 mass parts. The surface strength of the glossy layer is improved, and the gloss resistance of inkjet recording glossy paper is more excellent. When the content of the zirconium compound is less than 0.01 parts by mass, the effect of improving the scratch resistance is poor, and when the content exceeds 20 parts by mass, the ink absorbability may be adversely affected.

  Further, in the glossy paper for ink jet recording according to the present embodiment, the glossy expression layer preferably contains silanol-modified polyvinyl alcohol as a binder. Since the silanol-modified polyvinyl alcohol has extremely high adhesion to inorganic substances, the surface strength can be increased because the coagulation force is strong while the ink absorbability and glossiness are balanced at a high level. The degree of modification and the degree of polymerization of the silanol-modified polyvinyl alcohol can be appropriately selected.

  In the glossy paper for ink jet recording according to this embodiment, the glossy expression layer preferably contains a cationic acrylic resin as a binder. The cationic acrylic resin has an effect of improving glossiness by enhancing the adhesion between the cast drum and the coating layer. In addition, since the cationic acrylic resin has high transparency, it is difficult to impair the transparency of the glossy layer, the image clarity is good, and the light resistance is excellent, so that the storage stability of the glossy paper for inkjet recording according to the present embodiment is improved. The effect that it is hard to make it worse is also acquired.

  In the glossy paper for ink jet recording according to the present embodiment, the cationic acrylic resin is preferably a cationic acrylic silicone resin. Since the cationic acrylic silicone resin is further excellent in drum adhesion, the glossy paper for ink jet recording according to the present embodiment has a high gloss feeling and is more excellent in scratch resistance.

  Examples of the cationic acrylic silicone resin include a block polymer or a graft polymer prepared by reacting an acrylic acid polymer with an organopolysiloxane. As this organopolysiloxane, there is a linear polymer having an —OH functional group, and there are the following compounds.

但し、ｎは、１０〜５０００。

However, n is 10 to 5000.

  The aforementioned acrylic acid polymer is a polymer or copolymer obtained by polymerizing a monomer such as an α, β-unsaturated acid or its ester. Examples of the α, β-unsaturated acid or ester thereof include acrylic acid, methacrylic acid, or methyl ester, ethyl ester, butyl ester, stearyl ester, 2-ethylhexyl ester, 2-hydroxyethylhexyl ester or 3 thereof. -Hydroxypropyl esters. Examples of the comonomer that is polymerized with the α, β-unsaturated acid or its ester include maleic acid, itaconic acid, fumaric acid, styrene, α-methylstyrene, vinyl acetate, and vinyl propionate.

  Furthermore, as other binders that can be used in combination with the above-described binder of the glossy layer, for example, polyvinyl alcohol, polyvinyl acetal, oxidized starch, etherified starch, carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, soy protein, Polyethylene imide resin, polyvinyl pyrohydrin resin, polyacrylic acid or copolymer thereof, maleic anhydride copolymer, acrylamide resin, acrylate ester resin, polyamide resin, polyurethane resin, polyester resin, Polyvinyl butyral resin, alkyd resin, epoxy resin, epichlorohydrin resin, urea resin, melamine resin, styrene / butadiene copolymer, methyl methacrylate / butadiene copolymer, acrylic ester, methacrylic Acrylic polymer latexes of polymers or copolymers of esters, styrene-acrylic resins, there are resins of vinyl polymer latexes such as ethylene-vinyl acetate copolymer.

  The binder content of the glossy layer is determined in consideration of the printability of the recording medium, the strength of the glossy layer, and the coating liquid property. In the glossy paper for ink-jet recording according to this embodiment, the content of the binder in the glossy expression layer is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the pigment contained in the glossy expression layer. More preferably, it is -25 mass parts. When the binder content of the glossy layer is less than 5 parts by mass, the strength of the coating layer is inferior, and when it exceeds 30 parts by mass, the ink absorbency is adversely affected.

  Furthermore, in the glossy expression layer, a cationic polymer, a release agent, a dispersant, a thickener, an antiseptic, an antifoaming agent, a coloring dye, a coloring pigment, a fluorescent whitening agent, for fixing an ink for inkjet recording, You may add suitably selecting additives, such as a water-proofing agent, a leveling agent, antioxidant, or an ultraviolet absorber.

The glossy expression layer in the present embodiment may be applied using a known coating machine such as an air knife coater, roll coater, reverse roll coater, bar coater, comma coater, or blade coater. The coating amount at this time is preferably 3 to 40 g / m ^{2 in} terms of solid content, and more preferably 5 to 30 g / m ² . When the coating amount exceeds 40 g / m ² , the productivity is inferior, and when the coating amount is less than 3 g / m ^2, it becomes difficult to form a glossy surface.

  The gloss development layer in this embodiment has a surface image clarity (JIS H8866-2: 1999 “Image quality test method of anodized film of aluminum and aluminum alloy—Part 2: Instrument measurement method”) of 55% or more. is there. In order to realize the above image clarity, in the glossy paper for ink jet recording according to the present embodiment, the gloss developing layer is formed by applying a coating liquid containing a pigment and a binder onto the ink receiving layer. After forming, the case where it forms by the cast coat method formed by crimping | bonding a coating layer to the metal surface of the mirror-finishing heated is included. As the cast coating method, a wet method, a coagulation method, or a rewetting method is known. In the glossy paper for ink jet recording according to the present embodiment, the gloss developing layer is formed by the coagulation method of the cast coating method, and is used as a coagulant. It preferably contains a boron compound. In the coagulation method, it is important to select a coagulant that effectively coagulates with the binder of the coating layer, and sodium borate and / or boric acid is more preferable. It is also possible to add a cationic polymer for fixing the ink to the coagulant. By adjusting the time from application to application of the coagulant, the time from application of the coagulant to reaching the cast drum, the temperature of the cast drum, the pressure during crimping, and the line speed A high glossy layer can be formed. About these various conditions, it is necessary to optimize by calculating | requiring optimal conditions according to the installation to be used and a coating liquid.

  Moreover, you may perform calendar processes, such as a machine calendar, a soft calendar, or a super calendar, after the process by the cast coat method. Further, the curl adjustment can be performed by applying water or curling agent on the back surface or by humidifying the surface.

(Configuration of ink receiving layer)
The glossy paper for ink jet recording according to this embodiment is provided with one or more ink receiving layers on a base material and below the glossy expression layer. The ink receiving layer is composed of a white pigment and a binder.

  The pigment used in the ink receiving layer contains at least one known white pigment, such as kaolin, talc, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, titanium dioxide, zinc oxide, zinc sulfate, zinc carbonate, calcium silicate. And white inorganic pigments such as aluminum silicate, magnesium silicate, diatomaceous earth, aluminum hydroxide, magnesium hydroxide, satin white, synthetic silica, colloidal silica or alumina, or organic pigments such as acrylic, styrene, ethylene, vinyl chloride or nylon.

  Examples of the binder for the ink receiving layer used in the present embodiment include polyvinyl alcohol, polyvinyl acetal, oxidized starch, etherified starch, carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, soybean protein, polyethyleneimide resin, and polyvinyl pyrone. Hydrin resin, polyacrylic acid or copolymer thereof, maleic anhydride copolymer, acrylamide resin, acrylate resin, polyamide resin, polyurethane resin, polyester resin, polyvinyl butyral resin, alkyd resin , Epoxy resin, epichlorohydrin resin, urea resin, melamine resin, styrene / butadiene copolymer, methyl methacrylate / butadiene copolymer, acrylic ester, methacrylic ester polymer There are acrylic polymer latexes such as copolymers, and vinyl polymer latex resins such as ethylene / vinyl acetate copolymers. One of these can be used alone, or two or more can be used in combination. May be. The amount of the binder used in the ink receiving layer is determined in consideration of the printability of the recording medium, the strength of the ink receiving layer, and the coating liquid property. Usually, the binder for the ink receiving layer is preferably added in an amount of 1 to 200% by mass, more preferably 5 to 100% by mass, based on the weight of the pigment contained in the ink receiving layer. When the addition amount of the binder in the ink receiving layer is less than 1% by mass, the strength of the coating layer is inferior. On the other hand, if it exceeds 200% by mass, the ink absorbency is adversely affected.

  In this embodiment, it is preferable to add a cationic polymer in addition to the pigment and binder of the ink receiving layer. The action of the cationic polymer reacts with an anionic component in the dye used in the ink to form a salt that is insoluble in water, thereby fixing the ink and improving the water resistance. Examples of the cationic polymer include polyethyleneimine, epichlorohydrin-modified polyalkylamine, polyamine polyamide epichlorohydrin, dimethylamine ammonia epichlorohydrin, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl methacrylate hydrochloride. , Polyvinylpyridium halide, cationic polyacrylamide, cationic polystyrene copolymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride sulfur dioxide copolymer, diallyldimethylammonium chloride amide copolymer, dicyandiamide formalin polycondensate, Dicyandiamide diethylenetriamine polycondensate, poly Rylamine, polyallylamine hydrochloride, polyacrylamide resin, polyamide epoxy resin, melamine resin acid colloid, urea resin, cation modified polyvinyl alcohol, amino acid type amphoteric surfactant, betaine type compound or other quaternary ammonium salts or polyamines is there. The addition amount of the cationic polymer is not particularly limited, but it is preferably 1 to 50 parts by mass, more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the pigment contained in the ink receiving layer. When the addition amount of the cationic polymer is less than 1 part by mass, the ink water resistance is poor. Moreover, when it exceeds 50 mass parts, it has a bad influence on ink absorptivity.

  Additives to ink receiving layers other than cationic polymers include antifoaming agents, lubricants, dispersants, wetting agents, fluorescent brighteners, colored dyes, colored pigments, thickeners, preservatives, water resistance agents, UV absorption An agent or an antioxidant may be used as necessary.

The ink receiving layer in the present embodiment may be coated using a known coating machine such as an air knife coater, roll coater, bar coater, comma coater, or blade coater. The coating amount at this time is not particularly limited and is preferably in terms of solid content 3 g / m ² or more, and more preferably set to 5 to 20 g / m ^2. When the coating amount is less than 3 g / m ² , the ink absorbability may be inferior.

  In addition, a known calendar device such as a super calendar, a machine calendar, or a soft calendar may be used in order to obtain a certain smoothness after coating the ink receiving layer.

(Structure of base material)
The base material used in the present embodiment is, for example, a normal paper base material such as high quality paper, medium quality paper, or white paperboard. Considering the case of recycling as fuel, use ECF (no molecular chlorine) and / or TCF (no chlorine compound) pulp as raw pulp as chlorine-free bleached pulp with low chlorine content It is preferable.

  In order to suppress excessive penetration of the coating liquid at the time of cast coating, it is preferable to use a base paper coated with a water-soluble polymer such as starch or polyvinyl alcohol with a size press.

  EXAMPLES Hereinafter, although an Example is given and this invention is further explained in full detail, this invention is not limited to these examples. Further, “parts” and “%” shown in the examples represent solid mass parts and solid mass% unless otherwise specified.

(Example 1)
A high-quality paper having a basis weight of 160 g / m ² surface-treated with oxidized starch, 100 parts by mass of synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.), and 10 masses of polyvinyl alcohol (PVA117: manufactured by Kuraray Co., Ltd.) as a binder. And 40 parts by mass of ethylene / vinyl acetate (Polysol EVA AD-6: manufactured by Showa Polymer Co., Ltd.) and 30 parts by mass of a cationic polymer (Papiogen P-105: manufactured by Senka Co., Ltd.) as an additive. The coating liquid was applied with an air knife coater so as to have an absolutely dry coating amount of 10 g / m ² and dried to coat the ink receiving layer. Next, 80 parts by mass of alumina having a BET specific surface area of 55 m ² / g (PG-003, crystal form-γ, θ mixture: manufactured by CABOT) and alumina-modified silica (VP3375: manufactured by Nippon Aerosil Co., Ltd.) 20 as the pigment of the glossy layer. 3 parts by mass, 3 parts of zirconium nitrate (Zircosol ZN: manufactured by Daiichi Rare Element Chemical Co., Ltd.) as a zirconium compound, 10 parts of polyvinyl alcohol (PVA420: manufactured by Kuraray Co., Ltd.) as a binder, and a cationic polymer (Smiles as an additive) Resin 1001: Sumitomo Chemical Co., Ltd.) 10 parts by mass and polyethylene emulsion (SN coat 287: Sannopco Co., Ltd.) 1 part by mass as a release agent were used to obtain a coating solution having a solid content of 20%. This coating solution was applied with an air knife coater so that the dry coating amount was 10 g / m ^2, and then solidified by applying a 3% aqueous solution of sodium borate. While the surface was wet, it was pressure-bonded to a cast drum having a surface temperature of 100 ° C. to produce glossy paper for ink jet recording.

(Example 2)
60 parts by mass of alumina having a BET specific surface area of 150 m ² / g (AKP-G015, crystal form-γ type: manufactured by Sumitomo Chemical Co., Ltd.) and 40 parts by mass of alumina-modified silica (VP3375: manufactured by Nippon Aerosil Co., Ltd.) Except that, glossy paper for inkjet recording was produced under the conditions described in Example 1.

(Example 3)
80 parts by mass of alumina having a BET specific surface area of 80 m ² / g (AKP-G008, crystal form-θ type: manufactured by Sumitomo Chemical Co., Ltd.) and 20 parts by mass of alumina-modified silica (VP3375: manufactured by Nippon Aerosil Co., Ltd.) Except that, glossy paper for inkjet recording was produced under the conditions described in Example 1.

Example 4
50 parts by mass of alumina having a BET specific surface area of 220 m ² / g (TM-300, crystal form-γ type: manufactured by Daimei Chemical Co., Ltd.) and 50 parts by mass of alumina-modified silica (VP3375: manufactured by Nippon Aerosil Co., Ltd.) Except that, glossy paper for ink-jet recording was produced under the conditions described in Example 1.

(Example 5)
As a binder for the glossy layer, 2 parts by mass of silanol-modified polyvinyl alcohol (R-1130: manufactured by Kuraray Co., Ltd.), 5 parts by mass of polyvinyl alcohol (PVA420: manufactured by Kuraray Co., Ltd.) and a cationic acrylic resin (Vinyl Blanc 2580: Nisshin Chemical) A glossy paper for ink-jet recording was produced under the same conditions as described in Example 1 except that the amount was 7 parts by mass.

(Example 6)
As a binder for the glossy layer, silanol-modified polyvinyl alcohol (R-1130: manufactured by Kuraray Co., Ltd.) 2 parts by mass, polyvinyl alcohol (PVA420: manufactured by Kuraray Co., Ltd.) 5 parts by mass, and a cationic acrylic silicone resin (Aquabrid 922: Daicel). A glossy paper for ink-jet recording was produced under the same conditions as described in Example 1 except that the amount was 7 parts by mass.

(Example 7)
A glossy paper for ink-jet recording was prepared under the same conditions as described in Example 1 except that 3 parts of zirconium acetate (manufactured by Nippon Light Metal Co., Ltd.) was used as the zirconium compound of the glossy layer.

(Example 8)
A glossy paper for ink-jet recording was prepared under the same conditions as described in Example 1, except that 3 parts of hydroxy zirconium chloride (manufactured by Nippon Light Metal Co., Ltd.) was used as the zirconium compound of the glossy layer.

Example 9
As a pigment of the glossy layer, 80 parts by mass of alumina having a BET specific surface area of 55 m ² / g (PG-003, crystal form-γ, θ mixture: manufactured by CABOT) and 20 masses of alumina-modified silica (Sylojet 4001: manufactured by Grace Devison) A glossy paper for ink-jet recording was produced under the same conditions as described in Example 1 except that the parts were used.

(Example 10)
As a pigment for the glossy layer, 80 parts by mass of alumina having a BET specific surface area of 55 m ² / g (PG-003, crystal form-γ, θ mixture: manufactured by CABOT) and alumina-modified silica (silica doll 20P: manufactured by Nippon Chemical Co., Ltd.) A glossy paper for inkjet recording was produced under the same conditions as described in Example 1 except that the amount was 20 parts by mass.

(Example 11)
As a pigment of the glossy layer, 80 parts by mass of alumina having a BET specific surface area of 55 m ² / g (PG-003, crystal form-γ, θ mixture: manufactured by CABOT), 10 mass of alumina-modified silica (VP3375: manufactured by Nippon Aerosil Co., Ltd.) A glossy paper for ink-jet recording was produced under the same conditions as described in Example 1 except that 10 parts by mass and gas phase method silica (Aerosil 200: manufactured by Nippon Aerosil Co., Ltd.) were used.

(Comparative Example 1)
Ink jet under the same conditions as described in Example 1 except that 100 parts by mass of alumina (AKP-30, crystal form-α type: manufactured by Sumitomo Chemical Co., Ltd.) having a BET specific surface area of 10 m ² / g was used as the pigment of the glossy layer. A glossy recording paper was prepared.

(Comparative Example 2)
As described in Example 1, except that 100 parts by mass of alumina having a BET specific surface area of 275 m ² / g (cataloid AP-1, crystal form-pseudo-boehmite type: manufactured by Catalyst Kasei Co., Ltd.) was used as the pigment of the glossy layer. A glossy paper for inkjet recording was prepared under the conditions described above.

(Comparative Example 3)
Under the same conditions as described in Example 1, except that 100 parts by mass of alumina having a BET specific surface area of 220 m ² / g (TM-300, crystal form-γ type: manufactured by Daimei Chemical Co., Ltd.) was used as the pigment of the glossy layer. A glossy paper for ink jet recording was prepared.

(Comparative Example 4)
The conditions as described in Example 1 were used except that 100 parts by mass of alumina having a BET specific surface area of 55 m ² / g (PG-003, crystal form-γ, θ mixture: manufactured by CABOT) was used as the pigment of the glossy layer. A glossy paper for ink jet recording was prepared.

(Comparative Example 5)
A glossy paper for ink jet recording was prepared under the same conditions as described in Example 1 except that zirconium nitrate (Zircosol ZN: manufactured by Daiichi Rare Element Chemical Industries, Ltd.) was not added as the zirconium compound of the glossy layer.

(Comparative Example 6)
A glossy paper for ink-jet recording was prepared under the same conditions as described in Example 1, except that 100 parts by mass of pearl necklace-shaped colloidal silica (Snowtex PS-MO: manufactured by Nissan Chemical Industries, Ltd.) was used as the pigment of the glossy layer. .

(Comparative Example 7)
A glossy paper for ink-jet recording was produced under the same conditions as described in Example 1 except that the ink receiving layer was not provided.

  The following tests were carried out on the glossy paper for ink jet recording, and the results are shown in Tables 1 and 2.

(Image clarity)
An ISO standard image (ISO / JIS-SCID high-definition color digital standard image data, image name: portrait, image identification number: N1) was printed using an ink jet printer “PM-900C” manufactured by Seiko Epson Corporation. The printed image was visually observed to evaluate the image clarity.
A: The recorded image is very clear and has a clear contrast, which is good in practical use.
○: The recorded image is clear and the contrast is clear, and there is no practical problem.
(Triangle | delta): The recorded image is clear, but contrast is not clear, the color is sinking, and there exists a problem in practical use.
X: The recorded image is unclear and the color is sunk, impractical.

(Ink absorption)
CMYK and RGB solid (100% density) and characters were printed using an Seiko Epson inkjet printer “PM-900C”. The ink absorptivity was evaluated by visually observing the boundary of each color of the solid portion and the degree of bleeding of the characters.
(Double-circle): The boundary is clear, there is no blur, a character is clear, and it is practically favorable.
○: The blurring of the boundary is not conspicuous, the characters are clear, and there is no practical problem.
(Triangle | delta): The blur of a boundary is conspicuous, a character is unclear, and there exists a problem practically.
X: The blurring of the boundary is severe, the characters cannot be identified, and cannot be used practically.

(Image clarity)
The image clarity was measured in order to evaluate the glossiness of the surface of the glossy layer. The image clarity is in accordance with JIS H8866-2: 1999 “Image clarity test method for anodized films of aluminum and aluminum alloys—Part 2: Instrument measurement method” with an optical comb width of 2 mm and an incident / reflection angle of 60 °. It measured and evaluated with the image clarity measuring device (ICM-1T: Suga Test Instruments company make). At this time, if the image clarity is 55% or more, the reflected image is clearly visible and excellent in glossiness, and there is no practical problem. On the other hand, if the image clarity is less than 55%, the reflected image is unclear, inferior in gloss, and has a practical problem.

(Abrasion resistance)
A set of 20 glossy papers for inkjet recording is set on an offset printing machine (LITHRON40, manufactured by KOMORI), and the surface of the glossy layer generated when the back side is printed at a printing speed of 8000 sheets / hour The degree was visually checked and scratch resistance was evaluated.
(Double-circle): There is no scratch and it is favorable and is practically favorable.
○: Scratches are slightly observed, but there is no practical problem.
Δ: Scratches are clearly recognized, and there is a problem in practical use.
X: Scratch was remarkably observed and impractical.

(Evaluation results)
As is apparent from Tables 1 and 2, the glossy layer provided on one or more ink-receiving layers has at least one of θ-alumina or γ-alumina and the surface of silica modified with alumina. The glossy paper for ink-jet recording of Examples 1 to 11 containing alumina-modified silica as a pigment and containing a zirconium compound has higher print quality and gloss than the glossy paper for ink-jet recording of Comparative Examples 1 to 7. It was found to be excellent in feeling and scratch resistance.

Claims (11)

One or more ink-receiving layers are provided on at least one side of the paper substrate, and a gloss-expressing layer mainly composed of a pigment and a binder is provided on the ink-receiving layer. By applying a coating solution containing the pigment and the binder on the layer to form a coating layer, the coating layer is then pressure-bonded to a heated mirror-finished metal surface by a cast coating method. And the gloss developing layer contains at least one of θ-alumina or γ-alumina and alumina-modified silica whose surface is modified with alumina as the pigment, and zirconium. An ink jet containing a compound and having a BET specific surface area of 50 to 220 m ² / g of θ-alumina and / or γ-alumina contained as the pigment. Glossy paper for jet recording. The θ-alumina and / or the γ-alumina contained as the pigment is contained in the glossy layer in a ratio of 50% by mass to 80% by mass of the pigment. 2. Glossy paper for ink-jet recording as described in 1.   3. The inkjet according to claim 1, wherein the glossy layer contains at least one of zirconium nitrate, zirconium acetate, and hydroxy zirconium chloride as the zirconium compound, or a mixture of two or more thereof. Glossy paper for recording. The content of the zirconium compound is 0.01 to 20 parts by mass in terms of ZrO _{2 with} respect to 100 parts by mass of the pigment contained in the glossy layer. The glossy paper for ink-jet recording as described. The content of the alumina that modify the surface of the silica, inkjet according to claim 1, 2, 3 or 4, characterized in that a 1 × 10 -4 ^{to 20%} by weight relative to the silica Glossy paper for recording.   6. The glossy paper for ink-jet recording according to claim 1, wherein the glossy layer further contains gas phase method silica as the pigment.   The glossy paper for ink-jet recording according to claim 1, wherein the glossy layer contains silanol-modified polyvinyl alcohol as the binder.   The glossy paper for ink-jet recording according to claim 1, wherein the glossy layer contains a cationic acrylic resin as the binder.   The glossy paper for ink-jet recording according to claim 8, wherein the cationic acrylic resin is a cationic acrylic silicone resin.   The content of the binder in the glossy expression layer is 5 to 30 parts by mass with respect to 100 parts by mass of the pigment contained in the glossy expression layer. The glossy paper for ink jet recording according to 4, 5, 6, 7, 8, or 9. The glossy layer, the formed by the coagulation cast coating method, according to claim 1, characterized by containing a boron compound as a coagulating agent, 2,3,4,5,6,7,8, The glossy paper for ink jet recording according to 9 or 10.