JP2017193059A - Glossy paper for inkjet and method for producing the same - Google Patents

Abstract

An object of the present invention is to provide a glossy paper for inkjet which is high-quality glossy paper and has good transportability. An inkjet glossy paper according to the present invention is an inkjet glossy paper in which an ink receiving layer containing a pigment and a binder is provided on one side of a paper substrate. H 8686-2: 1999, “The imaging test method of anodized film of aluminum and aluminum alloy” was 55% or more under the condition of an optical comb width of 2 mm and an incident reflection angle of 60 °, and the ink receiving layer was provided. The Beck smoothness of the opposite surface is 20 seconds or less. [Selection figure] None

Description

  The present disclosure relates to glossy paper for ink jet that is excellent in transportability of a reversal paper feed type printer.

  The ink jet recording system is a system in which ink droplets are ejected and deposited on recording paper to form dots and recording is performed. In recent years, recording with high print quality has become possible due to technological advances in ink jet printers, inks, and recording media. As these ink jet recording-dedicated media, a medium having a pigment coating layer mainly composed of a pigment and a binder on the surface and using paper and / or film as a support is often used.

  Inkjet dedicated media are further classified into matte and glossy media from the surface state. The latter glossy medium is used when image quality closer to silver halide photography is required.

  As a method for producing a glossy medium, general methods include a method of forming an ink receiving layer by a casting method and imparting gloss to the surface, and a method of forming an ink receiving layer on a photographic paper base.

  The latter substrate for photographic paper is generally formed of a polyethylene film layer on a paper substrate, as is commonly called RC paper (resin coated paper). Since the film layer is smooth, the surface of the ink receiving layer is also smooth and a glossy surface is easily formed.

  However, the overall cost needs to be increased in order to increase ink absorbency, and the base material itself is more expensive than paper, so it is higher than the former glossy media produced by the casting method. . In addition, when it is discarded, there is a problem that it cannot be recycled because it is a composite material.

  On the other hand, in recent years, personal inkjet printers place emphasis on design, and there are an increasing number of reversal paper feed type printers with a compact housing. In this type of printer, for example, when printing on the ink receiving layer, the opposite side of the ink receiving layer is set up, and when the paper is fed, the paper is reversed and printed on the ink receiving layer. Unlike conventional rear-feed type printers, the paper feed mechanism is complicated, and poor conveyance such as double feed (here, double feed is a phenomenon in which multiple sheets are fed together) There is a problem that tends to occur. In particular, in the case of glossy paper for inkjet, there is a tendency that the coefficient of friction between the glossy surface and the opposite surface tends to be large, so that conveyance failure tends to occur. In addition, the higher the image clarity, the easier the paper and paper are brought into close contact with each other, leading to poor transport such as double feeding. In addition, since postcards are lightweight, they tend to be more likely to cause double feeding. Conventionally, various proposals have been made for the purpose of improving transportability. For example, there is a proposal to improve transportability by defining the pigment and binder of the ink receiving layer (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2015-174440

  However, in the case of the technique described in Patent Document 1, there is a problem that poor conveyance is likely to occur when the image clarity of the glossy surface increases.

  As described above, it is more difficult to completely complete the transportability of the reversing paper feed type printers that have been widely used in recent years when the medium to be used is inkjet glossy paper so that the transport failure is eliminated.

  Accordingly, an object of the present disclosure is to provide an inkjet glossy paper that is high-quality glossy paper with high image clarity and good transportability. More specifically, when multiple sheets of paper are set in the printer, even though they are high-quality glossy paper, an appropriate gap is generated between the sheets, and the sheets are easily separated during feeding, and multiple feeding is possible. It is an object to provide glossy paper for ink jet that is difficult to occur.

  The inkjet glossy paper according to the present invention is an inkjet glossy paper in which an ink receiving layer containing a pigment and a binder is provided on one side of a paper substrate, and the image receptivity of the ink receiving layer is JIS H 8686-2. : 55% or more under the condition of an optical comb width of 2 mm and an incident reflection angle of 60 ° according to 1999 “Image clarity test method of anodized film of aluminum and aluminum alloy” and opposite to the surface provided with the ink receiving layer The Beck smoothness is 20 seconds or less.

  In the glossy paper for inkjet according to the present invention, the ink receiving layer preferably contains a porous fine pigment as the pigment. Due to the geometric shape of the porous fine pigment, when the ink receiving layer is formed, voids are easily formed in the layer, and the ink absorbability of the dye ink and the pigment ink is excellent.

In the glossy paper for inkjet according to the present invention, the porous fine pigment is one selected from gas phase method silica, precipitation method silica, γ-alumina, θ-alumina, boehmite (including pseudoboehmite), and alumina-modified silica. It is above, and it is preferable that the BET specific surface area of the said porous fine pigment is 100-400 m < ² > / g. It becomes possible to make the ink absorbability of dye ink and pigment ink more excellent.

  In the glossy paper for inkjet according to the present invention, the porous fine pigment preferably satisfies one or both of an average primary particle diameter of 5 to 30 nm and an average secondary particle diameter of 20 to 1000 nm. The balance between the ink absorbability of the pigment ink and the glossiness of the ink receiving layer is improved.

  In the glossy paper for inkjet according to the present invention, it is preferable that monodispersed spherical colloidal silica is distributed on the outermost surface of the ink receiving layer. The effect of improving the image clarity of the surface of the ink receiving layer, improving the scratch resistance, and reducing the friction coefficient is observed.

  The inkjet glossy paper according to the present invention is preferably a postcard paper in which the opposite surface of the ink receiving layer is an address surface. Since the postcard is lightweight, it is easy to cause double feeding. However, according to the present invention, the postcard has excellent transportability.

  An inkjet glossy paper manufacturing method according to the present invention is the inkjet glossy paper manufacturing method in which an ink receiving layer containing a pigment and a binder is provided on one side of a paper substrate, and the ink receiving layer is provided. A step of preparing a paper base material having a Beck smoothness of 10 to 40 seconds on the opposite side of the surface, and an ink receiving layer coating liquid containing the pigment and the binder. The coating layer is in a wet state with a step of forming a coating layer by coating on the surface and a coagulant containing 5% by mass or more of the coagulant for coagulating the binder with respect to the binder. And coating with a cast drum after applying and solidifying, and the image receptivity of the ink-receiving layer after passing through this step is JIS H 8686-2: 1999 “of aluminum and aluminum alloys. Image clarity test of anodized film 55% or more under the condition of an optical comb width of 2 mm and an incident / reflection angle of 60 ° according to the “method”, and the Beck smoothness of the surface opposite to the surface provided with the ink receiving layer is from 5 seconds to 20 seconds. And

  According to the present disclosure, it is possible to provide glossy paper for inkjet which is high-quality glossy paper and has good transportability. For example, even if a reversal paper feeding type personal ink jet printer that has been widespread in recent years is used, there is no conveyance failure such as double feeding, so the present invention is considered significant. Further, in the present disclosure, since paper is used as a base material, the manufacturing cost is low as compared with a photographic paper base material having a film layer, and it can be recycled when discarded, which is preferable from the viewpoint of effective use of resources. .

  Embodiments of the present invention will be described in detail below, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

  Commonly used pigments to be included in the coating liquid for forming the ink receiving layer of glossy paper for inkjet include precipitated silica, spherical colloidal silica, non-spherical colloidal silica in which a plurality of spherical colloidal silicas are connected, gas phase Examples thereof include silica, alumina (including boehmite and pseudoboehmite crystals), and alumina-modified silica.

  In addition, porous fine pigments such as gas phase method silica, alumina, and non-spherical colloidal silica in which a plurality of spherical colloidal silicas are linked are used for inkjet glossy paper due to their excellent ink absorption due to their extremely high specific surface area. Although it is a commonly used pigment, it is easy to form voids during film formation due to its geometric shape, and while it has excellent ink absorbability of dye ink and pigment ink, it has a high coefficient of friction and poor conveyance. Prone to occur.

  The porous fine pigment used in the present embodiment is a pigment in which primary particles aggregate to form secondary or higher particles, and the particles themselves have a void. The average primary particle size is preferably 5 to 30 nm, and the average secondary particle size (when the tertiary or higher is formed, the average particle size of the final aggregated shape) is preferably 20 to 1000 nm. Here, the average primary particle diameter is preferably 5 to 30 nm or the average secondary particle diameter is preferably 20 to 1000 nm or both. As a case where either one is satisfied, for example, when the primary particles cannot be visually recognized even when the fine structure of the porous fine pigment is observed, the secondary particles are observed. In the above particle diameter, more preferably, the average primary particle diameter is 5 to 25 nm and the average secondary particle diameter is 20 to 500 nm. The porous fine pigment used in the present embodiment has such a particle size, and gas phase method silica, precipitation method silica, gel method silica, non-spherical colloidal silica in which a plurality of spherical colloidal silicas are connected, boehmite (Including pseudoboehmite), γ-alumina, θ-alumina, σ-alumina, and alumina-modified silica are preferable. From the viewpoint of the ink absorbability and glossiness of the pigment ink, it is preferable to use gas phase method silica, precipitation method silica, γ-alumina, θ-alumina, boehmite (including pseudoboehmite), and alumina-modified silica. Furthermore, it is preferable to contain vapor phase method silica from the viewpoint of good balance between image clarity and ink absorbability.

Moreover, it is preferable that the BET specific surface area of the porous fine pigment used by this embodiment is 100-400 m < ² > / g. More preferably, it is 150-380 m < ² > / g, Most preferably, it is 180-350 m < ² > / g. When the BET specific surface area is less than 100 m ² / g, the image clarity of the pigment ink may be inferior. If the BET specific surface area exceeds 400 m ² / g, the viscosity of the coating solution may be too high, resulting in poor stability. Here, the BET specific surface area is a surface area per unit mass determined by the BET method. The BET method is a method for measuring the specific surface area of a powder by a gas phase adsorption method, and is a method for obtaining the total surface area, that is, the specific surface area of a 1 g sample from an adsorption isotherm. Usually, nitrogen gas is often used as the adsorbed gas, and the most frequently used method is to measure the amount of adsorption from the change in pressure or volume of the gas to be adsorbed. The most prominent expression for expressing the isotherm of multimolecular adsorption is the Brunauer, Emmett, and Teller equation, called the BET equation, which is widely used for determining the surface area. The adsorption amount is obtained based on the BET equation, and the surface area is obtained by multiplying the area occupied by one adsorbed molecule on the surface. Moreover, in the range which does not impair the effect of this invention, you may use together with the porous fine pigment whose BET specific surface area is less than 100 m < ² > / g.

  The particle diameter of the porous fine pigment used in the present embodiment can be determined mainly by a dynamic light scattering method (for example, DLS-6500, manufactured by Otsuka Electronics Co., Ltd.), and can be observed at a high magnification. It can also be obtained by direct observation with an emission electron microscope. When determining the average primary particle size, a field emission electron microscope is used, and when determining the average secondary particle size, the dynamic light scattering method is used. In the present disclosure, the average secondary particle diameter means the number average particle diameter of secondary particles.

  Further, as a binder to be contained in the ink receiving layer, polyvinyl alcohol (including modified polyvinyl alcohol such as silanol-modified polyvinyl alcohol and carboxyl-modified polyvinyl alcohol), polyvinyl acetal, oxidized starch, etherified starch, carboxymethylcellulose, hydroxy Ethyl cellulose, casein, gelatin, soy protein, polyethylene imide resin, polyvinyl pyrrolidone resin, polyacrylic acid or copolymers thereof, maleic anhydride copolymer, acrylamide resin, acrylate resin, polyamide resin, acrylic Resin, styrene-acrylic resin, polyurethane resin (including cationic polyurethane resin), polyester resin, polyvinyl butyral resin, alkyd resin, epoxy resin -Based resin, epichlorohydrin-based resin, urea resin, melamine resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic ester, methacrylic ester polymer or copolymer acrylic latex , Vinyl polymer latexes such as ethylene-vinyl acetate copolymer, composite resin of colloidal silica and acrylic resin, composite resin of colloidal silica and styrene-acrylic resin, etc. are exemplified, alone or in combination Used. The amount of the binder used is determined in consideration of the printability of the recording medium, the strength of the coating layer, the surface glossiness, the paint liquid property, and the like. Usually, it is preferable to add in the range of 1 to 100 parts by mass with respect to 100 parts by mass of the pigment. More preferably, it adds in 5-60 mass parts, More preferably, it is 10-50 mass parts. If the amount is less than 1 part by mass, the coating layer strength may decrease. If it exceeds 100 parts by mass, the ink absorbability may decrease.

  The coating liquid for the ink receiving layer preferably contains polyvinyl alcohol as a binder from the viewpoint of color developability.

It is preferable to add a cationic polymer to the ink receiving layer in addition to the pigment and the binder. The action of the cationic polymer is to react with an anionic component in the dye used in the ink to form a salt that is insoluble in water. Improves. Such cationic polymers include polyethyleneimine, epichlorohydrin-modified polyalkylamine, polyamine, polyamine polyamide epichlorohydrin, dimethylamine ammonia epichlorohydrin, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl methacrylate hydrochloride, polyvinyl Pyridium halide, cationic polyacrylamide, cationic polystyrene copolymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride sulfur dioxide copolymer, diallyldimethylammonium chloride amide copolymer, dicyandiamide formalin polycondensate, dicyandiamide diethylenetriamine Polycondensate Polyallylamine, 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, polyamidine type compound, other quaternary Ammonium salts are used. The addition amount is not particularly limited, but it is preferably added in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment. More preferably, it is added in the range of 5 to 40 parts by mass. If it is less than 1 part by mass, the water resistance of the printed part may be lowered. If it exceeds 50 parts by mass, the ink absorbability may be inferior.

  Furthermore, additives such as dispersants, thickeners, preservatives, antifoaming agents, colored dyes, coloring pigments, fluorescent brighteners, water resistance agents, antioxidants, and UV absorbers are added to the ink receiving layer. It can select suitably and can add.

As a coating method of the coating liquid for forming the ink receiving layer of this embodiment, known coating methods such as an air knife coater, roll coater, reverse roll coater, bar coater, comma coater, blade coater, simultaneous multilayer coater, etc. Although there is a machine tool, any one may be used. The coating amount is preferably in the range of 3 to 30 g / m ^{2 in} terms of solid content, and more preferably in the range of 5 to 25 g / m ² . When the coating amount exceeds 30 g / m ² , the productivity is inferior, and when the coating amount is less than 3 g / m ² , it is difficult to form a sufficiently glossy surface.

  The inkjet glossy paper according to the present invention is preferably produced by a known cast coating method. As the cast coating method, a wet method, a coagulation method, and a rewet method are known, and any method can be used. In the present embodiment, the coagulation method is preferable from the viewpoint of image clarity. The coagulation method is a method in which a coagulating liquid is applied and the coagulation treatment is performed while the coating layer is in a wet state, and then pressed against the cast drum. In the coagulation treatment, it is important to select a coagulant that effectively coagulates with the binder component of the coating layer. In this embodiment, for example, a boron compound can be used. A high concentration of the coagulating liquid is preferable because the coagulation force is increased and the scratch resistance is further improved. The content of the coagulant is preferably 5% by mass or more based on the binder that can coagulate. If it is less than 5% by mass, the surface strength may be lowered, and more preferably 10% by mass or more. The upper limit of the content of the coagulant is preferably 200% by mass or less with respect to the binder that can coagulate. It is also possible to add colloidal silica to the coagulation liquid. In that case, colloidal silica is present (distributed) on the outermost surface of the ink receiving layer, and there are effects such as improvement of image clarity of the glossy surface, improvement of scratch resistance of the glossy surface, and reduction of the friction coefficient of the glossy surface. The colloidal silica is preferably monodispersed spherical colloidal silica from the viewpoint of the above effects.

  Also, adjust the time from application of the ink receiving layer to application of the coagulation liquid, the time from application of the coagulation liquid to the cast drum, the cast drum temperature, pressure during pressure bonding, and the line speed. By doing so, a surface with high glossiness can be formed. These various conditions need to be optimized by obtaining optimum conditions according to the equipment and paint used.

  In addition, calendar processing such as machine calendar, soft calendar, super calendar, etc. may be performed after cast processing, and for curl adjustment, water, curling agent etc. are coated on the back side or humidified to adjust curl. Can also be done.

Furthermore, the image receiving layer having an optical comb width of 2 mm and an incident reflection angle of 60 ° according to JIS H 8686-2: 1999 “Aluminum and aluminum alloy anodic oxide film imaging test method” has a mapping property of 55% or more. Is necessary from the viewpoint of glossiness. More preferably, the image clarity is 60% or more. If the image clarity is 60% or more, it can be said that the glossiness is further improved. Here, the reason for changing the incident / reflective angle from 45 ° described in JIS to 60 ° is to facilitate evaluation of the difference in glossiness.

  In the glossy paper for ink jet of this embodiment, it is preferable from the viewpoint of economy and ink absorbency to provide one or more under layers under the ink receiving layer. The under layer is mainly composed of a white pigment and a binder. The white pigment preferably contains synthetic silica. The binder contained in the under layer is preferably polyvinyl alcohol or ethylene-vinyl acetate.

  As the paper substrate having air permeability used in the present embodiment, paper substrates such as high-quality paper, medium-quality paper, and white paperboard can be used. In the present embodiment, it is preferable to use ECF (Elemental Chlorine Free) pulp or TCF (Totally Chlorine Free) pulp having a low chlorine content as a raw material pulp in consideration of the case where the fuel is recycled as fuel. As fillers to be used, known are heavy calcium carbonate, light calcium carbonate, magnesium carbonate, titanium oxide, synthetic silica, alumina, talc, calcined kaolin clay, kaolin clay, bentonite, zeolite, aluminum hydroxide, zinc oxide, etc. It is possible to use other pigments.

  In addition to the above pulp and filler, various papermaking chemicals such as known paper strength agents, sulfuric acid bands, yield improvers, sizing agents, dyes and fluorescent dyes are appropriately used in the paper stock. There is no particular limitation on the preparation method, blending, and addition method of each papermaking chemical for each paper, as long as the effects of this embodiment are not impaired. In addition, it is possible to make a paper using a known paper machine such as a circular net paper machine, a long net paper machine, and a twin-wire paper machine using the above-mentioned stock. It is also possible to use a multilayer paper having two or more layers as a base material.

  In order to suppress excessive penetration of the ink-receiving layer coating solution, it is preferable to apply a known water-soluble polymer such as starch, polyvinyl alcohol, or polyacrylamide to the paper base material with a size press or the like.

  In the inkjet glossy paper of the present invention, the Beck smoothness of the opposite surface of the ink receiving layer is 20 seconds or less. Preferably it is 19 seconds or less, More preferably, it is 18 seconds or less. When the Beck smoothness on the opposite surface of the ink receiving layer exceeds 20 seconds, there is a problem of double feeding. Although a minimum is not specifically limited, It is preferable that it is 5 second or more, More preferably, it is 10 second or more. When the Beck smoothness is less than 5 seconds, the surface of the ink receiving layer is blurred, and the image clarity tends to deteriorate. As a method for adjusting the Beck smoothness of the opposite surface of the ink receiving layer to 20 seconds or less, for example, the smoothness is appropriately adjusted by a wet press or a calendar at the time of paper base papermaking. Since the smoothness of the opposite surface of the ink receiving layer tends to decrease after the cast coating treatment, it is preferable to adjust the Beck smoothness higher than the final product. The paper base before the ink receiving layer is provided preferably has a Beck smoothness of 40 seconds or less. More preferably, it is 35 to 10 seconds. If it is less than 10 seconds, the glossy surface is blurred, and the image clarity of the glossy surface may be lowered. When the Beck smoothness of the paper substrate exceeds 40 seconds, there is a problem of double feeding.

  EXAMPLES Next, 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 indicate solid mass parts and solid mass% unless otherwise specified.

Example 1
(Formation of under layer)
A high-quality paper having a basis weight of 170 g / m ² obtained by surface-treating oxidized starch with a size press and Beck smoothness of the surface opposite to the surface on which the ink receiving layer was applied was adjusted to 35 seconds was used as a paper substrate. Next, 100 parts by mass of synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) as a pigment, 12 parts by mass of polyvinyl alcohol (PVA117: manufactured by Kuraray Co., Ltd.) and ethylene-vinyl acetate (Polysol EVA AD-10) : Showa High Polymer Co., Ltd.) 43 parts by mass, and further using a cationic polymer (Papiogen P-105: manufactured by Senka Co., Ltd.) 25 parts by mass, an under layer coating solution having a solid content concentration of 20% by mass was obtained. Subsequently, this under layer coating solution was applied and dried on one side of the paper base so that the dry coating amount was 10 g / m ² with an air knife coater, and an under layer was applied.
(Formation of ink receiving layer)
Next, 100 parts by mass of gas phase method silica (HDK T30, BET specific surface area 300 m ² / g, average primary particle size 10 nm, average secondary particle size 150 nm: manufactured by Wacker) as a pigment of the ink receiving layer coating liquid, binding 3 parts by mass of silanol-modified polyvinyl alcohol (PVA-R2105: manufactured by Kuraray Co., Ltd.), 10 parts by mass of polyvinyl alcohol (PVA-235, saponification degree 87 mol%, polymerization degree 3500: manufactured by Kuraray Co., Ltd.) and cationic polyurethane resin (Hydran CP) -7020: manufactured by Dainippon Ink & Chemicals Co., Ltd.) 5 parts by mass, and further mixed with 10 parts by mass of a cationic polymer (Himax SC-600L: manufactured by Hymo Co.) to improve ink fixation, and stirred with a serie mixer. Thus, an ink receiving layer coating solution having a solid content concentration of 18% was obtained. This ink receiving layer coating solution was applied onto the underlayer forming surface with an air knife coater so that the dry coating amount was 10 g / m ² . Next, while the ink receiving layer is in a wet state, 1.0% boric acid and 1.0% sodium borate as coagulants, monodispersed spherical colloidal silica (Snowtex YL, average particle diameter 80 nm: Nissan Wet coating amount 30 g using an aqueous solution containing 2.0% acrylic resin (Vinyl Blanc 2580, Nissin Chemical Industry Co., Ltd.) 0.5% as a coagulating liquid (concentration of coagulating liquid 4.5%) After further coating and coagulation treatment so as to be ² m ² , the coated layer surface obtained was pressure-bonded to a cast drum having a surface temperature of 105 ° C. while the surface of the coating layer was wet to produce glossy paper for inkjet. . The coagulant is boric acid or sodium borate, the binder capable of coagulation is the polyvinyl alcohol, and the content of the coagulant is 60% by mass with respect to the binder capable of coagulation.

(Example 2)
In Example 1, the glossy paper for inkjets was produced on the conditions as described in Example 1 except having adjusted the Beck smoothness of the paper base material to 33 second.

(Example 3)
In Example 1, except that the Beck smoothness of the paper base material was adjusted to 21 seconds, glossy paper for inkjet was produced under the conditions described in Example 1.

Example 4
In Example 1, γ-alumina (TM-300D, BET specific surface area 200 m ² / g, average primary particle size 10 nm, average secondary particle size 250 nm: manufactured by Daimei Chemical Industry Co., Ltd.) is used as a pigment of the ink-receiving layer coating solution. 70 parts by mass, 20 parts by mass of θ-alumina (TM-100, BET specific surface area 120 m ² / g, average primary particle size 14 nm, average secondary particle size 400 nm: manufactured by Daimei Chemical Co., Ltd.), precipitated silica (Fine Seal X -37B, BET specific surface area of 287 m ² / g, average primary particle size is unknown, average secondary particle size is 3.7 μm (manufactured by Tokuyama Corporation) Glossy paper was prepared.

(Example 5)
In Example 1, 100 parts by weight of boehmite (boehmite C01, BET specific surface area of 128 m ² / g, average primary particle diameter of 30 nm, average secondary particle diameter of 90 nm: manufactured by Daimei Chemical Co., Ltd.) as a pigment for the ink-receiving layer coating solution Except that, an inkjet glossy paper was produced under the same conditions as described in Example 1.

(Example 6)
As a pigment of the ink receiving layer, 55 parts by mass of vapor phase silica (HDK T30, BET specific surface area 300 m ² / g, average primary particle size 10 nm, average secondary particle size 150 nm: manufactured by Wacker), monodispersed spherical colloidal silica 45 A glossy paper for inkjet was produced under the same conditions as described in Example 1 except that the mass part (Snowtex AK-YL, average particle size 80 nm: manufactured by Nissan Chemical Industries, Ltd.) was used.

(Comparative Example 1)
In Example 1, glossy paper for inkjet was produced under the conditions described in Example 1, except that the Beck smoothness of the paper substrate was adjusted to 40 seconds.

(Comparative Example 2)
In Example 1, glossy paper for inkjet was produced under the same conditions as described in Example 1 except that the Beck smoothness of the paper substrate was adjusted to 60 seconds.

  The obtained glossy paper for inkjet was subjected to the following test, and the results are shown in Table 1.

(1) Measurement of Beck smoothness on the opposite side of the ink receiving layer (glossy surface):
The measurement was performed according to JIS-P8119.

(2) Image clarity of glossy surface (ink receiving layer surface):
The image clarity was measured in order to evaluate the specularity of the glossy surface of the obtained ink jet recording paper. The image clarity was measured with an image clarity measuring instrument (ICM-1T: manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS H 8686-2 with an optical comb width of 2 mm and an incident / reflection angle of 60 °. As an evaluation, when the image clarity is 55% or more, the reflected image is clearly visible and the glossiness is excellent. If it is less than 55%, the reflected image is unclear and inferior in gloss.

(3) Ink absorbability of dye ink:
Using an inkjet printer “ENVY5530” manufactured by Hewlett-Packard Co., using each ink of CMYK, solid (100% density) and characters of each ink of CMYK and solid (100% density) of RGB (Red-Green-Blue) and The characters were printed on the resulting inkjet recording paper. The boundary of each color of the solid portion and the degree of blurring of the characters were evaluated visually.
(Double-circle): The boundary is clear, there is no blur, a character is clear, and it can be used practically.
○: The blurring of the boundary is not conspicuous and the characters are clear and practical.
(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, and the character cannot be identified, so that it is not practical.

(4) Ink absorbability of pigment ink:
Using an ink-jet printer “PX-105” manufactured by Seiko Epson Corporation, using CMYK inks, solid (100% density) and characters of each CMYK ink and solid (100% density) of RGB (Red-Green-Blue) ) And characters were printed on the resulting ink jet recording paper. The boundary of each color of the solid portion and the degree of blurring of the characters were evaluated visually.
(Double-circle): The boundary is clear, there is no blur, a character is clear, and it can be used practically.
○: The blurring of the boundary is not conspicuous and the characters are clear and practical.
(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, and the character cannot be identified, so that it is not practical.

(5) Printer transportability:
Set the resulting inkjet glossy paper (postcard size) 5 sheets at a time on a reversing paper feed type inkjet printer (brother DCP-J940N, manufactured by Brother Industries, Ltd.), and repeat this 100 times. , Counted the number of double feeds.
A: The number of times of double feeding is 0, and it can be practically used.
○: The number of times of double feeding is 1-2, and it can be put into practical use.
(Triangle | delta): The frequency | count of double feeding is 3-5 times, and there exists a problem practically.
X: The number of times of double feeding is 6 times or more, impractical.

ベック平滑度（秒）（１）：インク受容層用塗工液を塗工する前の、塗工予定面の反対面の紙基材のベック平滑度
ベック平滑度（秒）（２）：キャストコート処理後の、インク受容層を設けた面の反対面のベック平滑度

Beck smoothness (second) (1): Beck smoothness of paper substrate on the opposite side of the surface to be coated before coating the ink receiving layer coating liquid Beck smoothness (second) (2): Cast Beck smoothness on the opposite side of the ink receiving layer after coating

  As is clear from Table 1, Examples 1 to 6 were superior in printer transportability compared to Comparative Examples 1 and 2.

In Comparative Examples 1 and 2, the Beck smoothness on the surface opposite to the ink receiving layer exceeds 20 seconds.
The transportability was bad.

Claims (7)

In the glossy paper for ink-jet with an ink receiving layer containing a pigment and a binder on one side of a paper substrate,
The image receptivity of the ink receiving layer is 55% or more under the condition of an optical comb width of 2 mm and an incident reflection angle of 60 ° according to JIS H 8686-2: 1999 “Method for testing image clarity of anodized film of aluminum and aluminum alloy”. An inkjet glossy paper, wherein the Beck smoothness of the surface opposite to the surface provided with the ink receiving layer is 20 seconds or less.   The glossy paper for inkjet according to claim 1, wherein the ink receiving layer contains a porous fine pigment as the pigment. The porous fine pigment is at least one selected from gas phase method silica, precipitation method silica, γ-alumina, θ-alumina, boehmite (including pseudoboehmite), and alumina-modified silica.
The glossy paper for ink jet according to claim 1, wherein the porous fine pigment has a BET specific surface area of 100 to 400 m ² / g.   The porous fine pigment satisfies any one or both of an average primary particle diameter of 5 to 30 nm and an average secondary particle diameter of 20 to 1000 nm. Glossy paper for inkjet.   The glossy paper for inkjet according to any one of claims 1 to 4, wherein monodispersed spherical colloidal silica is distributed on the outermost surface of the ink receiving layer.   The glossy paper for inkjet according to any one of claims 1 to 5, as a postcard paper, the opposite surface of the ink receiving layer being an address surface. In the method for producing glossy paper for ink jet, in which an ink receiving layer containing a pigment and a binder is provided on one side of a paper substrate,
Preparing a paper substrate having a Beck smoothness of 10 to 40 seconds on the opposite side of the surface on which the ink receiving layer is to be provided;
Applying an ink-receiving layer coating solution containing the pigment and the binder to the paper substrate to form a coating layer;
After the coagulant containing 5% by mass or more of the coagulant for coagulating the binder is applied while the coating layer is in a wet state and solidified, the coagulant is applied to the cast drum. A process of pressing, and
The image receptivity of the ink-receiving layer after passing through this step is determined under the condition of an optical comb width of 2 mm and an incident / reflecting angle of 60 ° according to JIS H 8686-2: 1999 “Method for testing image clarity of anodized film of aluminum and aluminum alloy”. A method for producing glossy paper for ink jets, characterized in that the Beck smoothness of the surface opposite to the surface provided with the ink receiving layer is 55% or more and 5 seconds or more and 20 seconds or less.