JP4536080B2 - Method for producing ink jet recording material - Google Patents

Description

  The present invention relates to a method for producing an ink jet recording material, and more particularly to a method for producing an ink jet recording material having a back coat layer that does not cause gloss fluctuation on the surface of the back coat layer when paper is passed through an ink jet printer.

  In recent years, due to remarkable progress of inkjet printers and plotters, it has become possible to easily obtain full-color and high-definition images.

  The ink jet recording system records images, characters, and the like by causing micro droplets of ink to fly and adhere to a recording material such as paper according to various operating principles. Inkjet printers and plotters have rapidly become popular in recent years in various applications as hard copy creation devices for image information such as letters and various graphics created by computers. In particular, color images formed by the multicolor ink jet method can obtain recordings that are comparable to multicolor printing by the plate making method and printing by the color photographic method, and in applications where the number of copies is small, It is widely applied because it costs less than printing and photographic technologies.

  As the inkjet recording method has become more precise and faster, the application has been expanded and the environment in which it is used has also been expanded. Along with this, ink jet printers and ink jet recording materials are required to have excellent characteristics such as curling aptitude and transportability in addition to various basic characteristics such as ink absorptivity, color development of printed parts and storage stability. It has come to be.

  FIG. 1 is a cross-sectional view schematically illustrating a paper feeding mechanism in a general ink jet printer. In the figure, reference numeral 1 denotes a paper feed roller, which is composed of a set of a driving roller 2 that contacts the back surface side of the ink jet recording material M and a driven roller 3 that contacts the front surface (recording surface) side of the ink jet recording material M. ing. 4 is a platen and 5 is a recording head. The drive roller 2 is driven to rotate while the rotation amount is controlled by using a drive motor as a power source, and the driven roller 3 rotates following the rotation of the drive roller 2, and the inkjet recording material M is fed at the nip portion between these two rollers. The ink-jet recording material M is sent to the platen 4 position while controlling the feed amount according to the print data sent from the host computer or the like while being pinched from the front and back. At the position of the platen 4, the ink ejection operation by the recording head 5 is performed in accordance with the control of the feed amount. As a result, the ink adheres to the inkjet recording material M in a predetermined pattern for each unit region, and finally the image Is formed.

  In such a paper feed mechanism, it is important that the feed amount control of the recording material by the paper feed roller 1 is performed with high accuracy. If the accuracy of the feed amount control is low, the ink droplet landing position is deviated. Banding and white spots will occur. Therefore, in order to realize high-precision paper feeding, a roller (surface irregularity roller) in which irregularities are formed on the surface of a high-rigidity roller has been adopted as the driving roller 2 constituting the paper feeding roller 1. ing. The surface uneven roller has a high friction coefficient on the surface in contact with the ink jet recording material, so that a sufficient friction coefficient can be secured even for slippery materials such as films, and the recording material can be conveyed with high accuracy. .

  On the other hand, in an inkjet recording material, the thermoplastic resin layer formed by laminating a thermoplastic resin on the back side and cooling and solidifying with a mirror-finished cooling roll is used to adjust the gloss and touch feeling, and the back side has a photographic paper tone. Recording materials having a texture have been proposed (for example, Patent Documents 1 and 2).

However, in an inkjet recording material, a logo or name offset printing is often applied on the surface opposite to the ink receiving layer so that the user can easily check the name of the sales company and the paper name. When an inkjet recording material having a back surface as described above is passed using an ink jet printer having a back surface, the back surface uneven roll and the back surface rub against each other, resulting in gloss fluctuations on the back surface, and logos and names are difficult to see. In some cases, the merchandise value was impaired.
JP 2006-95840 A JP 200695884 A

  The subject of this invention is providing the manufacturing method of the inkjet recording material which has a backcoat layer in which glossiness fluctuation | variation does not generate | occur | produce on the surface of a backcoat layer, when passing a paper to an inkjet printer.

As a result of diligent research to achieve the above object, a surface on the opposite side of the surface on which the ink-receiving layer is formed is formed by applying and drying the coating liquid of the ink-receiving layer on one side of the support. In the method for producing an ink jet recording material formed by coating and drying a backcoat layer coating solution containing at least a pigment and a binder, the surface of the backcoat layer is 75 before and after the abrasion resistance test (JIS-P8136). The difference in specular gloss (JIS-P8142) is 10 or less , and the pigment of the back coat layer has an average particle diameter of 0.5 to 2 times the thickness of the back coat layer in addition to the inorganic pigment and the inorganic pigment. The problem has been solved by a method for producing an ink jet recording material, characterized in that a backcoat layer coating liquid containing particles and latex is applied, dried, provided and controlled.

  Furthermore, the backcoat coating layer may adhere to the black cloth attached to the Gakushin type friction fastness tester due to wear, and the portion of the black cloth where the coating layer of the backcoat layer adheres and the part that does not adhere Is preferably a back coat layer in which the difference in numerical values measured using an optical densitometer (SpectroEye, manufactured by GretagMacbeth) is less than 0.6. If it exceeds this value, the printed portion of the logo or the like may be peeled off together with the coating layer of the backcoat layer when the printer passes the paper.

  In the method for producing an ink jet recording material of the present invention, no gloss fluctuation occurs on the surface of the backcoat layer when the paper passes through the ink jet printer.

  The method for producing the ink jet recording material according to the present invention will be described below.

  The abrasion resistance test according to the present invention conforms to JIS-P8136.

  In the wear resistance test of the present invention, a Gakushin type friction fastness tester (manufactured by Tester Sangyo) was used, and a black cloth (bilikken moss) was attached to the friction part, and after 30 reciprocations at a load of 500 gf, the back The 75 degree specular gloss (JIS-8142) of each of the rubbing portion and non-rubbing portion on the surface of the coat layer is measured, and the difference between the measured values is controlled to 10 or less. The glossiness is preferably 8 or less, more preferably 6 or less. If the gloss difference is less than this value, the gloss difference after passing through the printer is inconspicuous and good.

  In the production method of the present invention, it is possible to control and suppress the gloss fluctuation of the backcoat layer. A method of measuring the 75-degree specular gloss (JIS-8142) of each of the rubbing portion and the non-rubbing portion on the surface of the backcoat layer and controlling the difference between the measured values to 10 or less in the friction resistance test of the present invention. (1) A method in which a polyurethane resin latex or a carboxylated styrene-butadiene copolymer latex is applied and dried, and a back coat layer is provided and controlled. (2) A gas phase having an average primary particle diameter of 5 to 50 nm. A method of applying and drying a backcoat layer coating liquid composed of inorganic fine particles such as silica, colloidal silica, and alumina hydrate and a hydrophilic binder, and controlling by providing a backcoat layer. (3) Organic pigment as main component Used, a method of applying and drying a backcoat layer coating solution containing latex as a binder, and providing a backcoat layer to control, (4) inorganic pigment and backcoat Examples include a method of coating and drying a backcoat layer coating solution containing particles having an average particle diameter of 0.5 to 2 times the thickness of the layer and a latex, and providing and controlling the backcoat layer. ) Is preferred. Furthermore, gloss fluctuations can be controlled and suppressed by appropriately adjusting the coating amount, drying conditions, blending ratio, etc. in the above (1) to (4).

  As the inorganic pigment used in the backcoat layer of the present invention, one or more known white pigments can be used. For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic non Examples thereof include white inorganic pigments such as crystalline silica, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, and magnesium hydroxide, and one or more of these can be used. Of these, light calcium carbonate, heavy calcium carbonate, kaolin, and talc are preferably used from the viewpoint of reducing gloss fluctuation and wear resistance of the coating layer.

  Examples of the binder used in the backcoat layer of the present invention include starch derivatives such as oxidized starch, etherified starch, and phosphate esterified starch; cellulose derivatives such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose; polyvinyl alcohol, or silanol Polyvinyl alcohol derivatives such as modified polyvinyl alcohol; natural polymers such as casein, gelatin and modified products thereof, soy protein, pullulan, gum arabic, karaya gum, albumin or derivatives thereof, vinyl polymers such as polyacrylamide, polyvinyl pyrrolidone, Hydrophilic binder such as alginic acid, polyethyleneimine, polypropylene glycol, polyethylene glycol, maleic anhydride or copolymer thereof, styrene-butadiene Copolymers, conjugated diene copolymer latexes such as methyl methacrylate-butadiene copolymer, acrylic copolymer latexes such as acrylate and methacrylate polymers or copolymers, ethylene-vinyl acetate copolymer Polymer, vinyl copolymer latex such as vinyl chloride-vinyl acetate copolymer, polyurethane resin latex, alkyd resin latex, unsaturated polyester resin latex, or a functional group-containing monomer such as carboxy group of these various copolymers. Examples thereof include latex binders such as functional group-modified copolymer latexes based on monomers, aqueous adhesives such as thermosetting synthetic resins such as melamine resins and urea resins, and polyvinyl butyral. One or more of these can be used. Among these, it is preferable to contain one or more hydrophilic binders and latex binders each because gloss fluctuation is reduced.

  As a compounding quantity of the binder used for the backcoat layer of this invention, it is 5-70 mass parts with respect to 100 mass parts of sum totals of an inorganic pigment, Preferably, it is 10-50 mass parts.

  In the present invention, the thickness range of the backcoat layer is preferably 3 to 30 μm, more preferably 5 to 20 μm.

  In the present invention, it is preferable to add particles having an average particle diameter of 0.5 to 2 times the thickness of the backcoat layer in addition to the inorganic pigment to the backcoat layer. In view of suppression of gloss fluctuation and wear resistance, 0.6 to 1.5 times is more preferable.

  The average particle diameter of the particles of the present invention includes the primary particles and the particle diameters of the secondary particles in which the primary particles are aggregated and integrated. It is obtained by measuring with a particle size distribution meter using a diffraction / scattering method.

  As particles to be added to the back coat layer in the present invention, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, Inorganic pigments such as diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, and composite particles coated with the above inorganic pigments with resin , Polyamide resin, polyester resin, polycarbonate resin, polyether resin, polyolefin resin, polysulfone resin, polystyrene resin, polyvinyl chloride resin, polyvinylidene chloride resin, ethylene-vinyl acetate copolymer resin, acrylic acid resin Mention may be made of ether and acrylic copolymer resins, such as polymers or copolymers of methacrylic acid esters, polyurethane resin, melamine resin, polyphenylene sulfide resin, the organic spherical particles, such as styrene copolymer resin.

  As a compounding quantity of the particle | grains used for the backcoat layer of this invention, it is 2.5-30 mass parts with respect to 100 mass parts of sum totals of an inorganic pigment, Preferably, it is 5-25 mass parts.

  Even when two or more kinds of the same kind of particles having different types of particles or different average particle sizes are used in the particles contained in the back coat layer, the average particle size, the added amount, etc. of the mixed particles are within the above range. By making it, the effect of suppressing gloss fluctuation can be obtained.

  In the present invention, the back coat layer has additives such as a pigment dispersant, a thickener, a fluidity improver, a surfactant, an antifoaming agent, an antifoaming agent, a release agent, a lubricant, a foaming agent, and a penetrating agent. Further, coloring dyes, coloring pigments, fluorescent brighteners, ultraviolet absorbers, antioxidants, preservatives, antibacterial agents, water resistance agents, wetting power enhancers, dry paper strength enhancing agents, and the like can be appropriately blended.

  In the present invention, the method for providing the backcoat layer may be either an on-machine coater or an off-machine coater. For example, various devices such as conventionally known air knife coaters, curtain coaters, die coaters, blade coaters, gate roll coaters, bar coaters, rod coaters, roll coaters, bill blade coaters, short dwell blade coaters, cast coaters, and size presses are turned on. It can be used in a machine or off-machine. Moreover, after coating, it is possible to finish using a calendar device such as a machine calendar, a TG calendar, a super calendar, or a soft calendar.

  The support used in the present invention may be transparent, translucent or opaque, such as paper, various nonwoven fabrics, woven fabric, synthetic resin film, synthetic resin laminated paper, synthetic paper, metal foil, ceramic paper, glass plate, etc. Alternatively, a composite sheet combining these can be arbitrarily used according to the purpose, but is not limited thereto.

  Examples of paper used as a support in the present invention include chemical pulps such as LBKP and NBKP, mechanical pulps such as GP, PGW, RMP, TMP, CTMP, CMP, and CGP, and wood pulp such as waste paper pulp such as DIP and conventionally known pulps. The main component is a pigment, and a binder, a sizing agent, a fixing agent, a yield improver, a cationizing agent, a paper strength enhancer and the like are mixed using one or more additives, and a long net paper machine, circular net paper machine, Paper manufactured with various devices such as twin wire paper machines, paper with size press or anchor coat layer with starch, polyvinyl alcohol, etc., art paper with coat layer on top Coated paper such as paper and cast coated paper is also included. Such a paper and coated paper may be provided with the coating layer in the present invention as they are, or a calendar device such as a machine calendar, a TG calendar, or a soft calendar may be used for the purpose of controlling flattening.

  The ink receiving layer according to the present invention consists of a coating composition containing an aqueous adhesive or the like in addition to a white pigment, and when applied to an ink jet recording system using both pigment ink and dye ink, In addition, a cationic compound can also be contained. In addition, as additives, dye fixing agents, pigment dispersants, thickeners, fluidity improvers, surfactants, antifoaming agents, antifoaming agents, mold release agents, foaming agents, penetrating agents, colored dyes, Coloring pigments, fluorescent whitening agents, ultraviolet absorbers, antioxidants, preservatives, antibacterial agents, water resistance agents, wetting power enhancers, dry paper strength enhancing agents, and the like can be appropriately blended.

  In the present invention, as the white pigment used for the support and the ink receiving layer, one or more known white pigments can be used. For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic non Crystalline silica, colloidal silica, gas phase method silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, white inorganic pigments, styrene plastic pigment, acrylic Organic pigments such as plastic pigment, polyethylene, microcapsule, urea resin, and melamine resin can be used. Among the white pigments described above, porous inorganic pigments are preferable, and examples thereof include porous amorphous synthetic silica, porous magnesium carbonate, and porous alumina.

  Examples of the aqueous polymer binder used in the aqueous adhesive of the ink receiving layer of the present invention include starch derivatives such as oxidized starch, etherified starch, and phosphate esterified starch; cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose; casein , Gelatin, soybean protein, polyvinyl alcohol, or polyvinyl alcohol derivatives such as silyl-modified polyvinyl alcohol; conjugated diene copolymers such as polyvinyl pyrrolidone, maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer Latex; Acrylic copolymer latex such as polymer or copolymer of acrylic ester and methacrylic ester; Vinyl copolymer latex such as ethylene-vinyl acetate copolymer; Functional group-modified copolymer latex with functional group-containing monomers such as carboxy groups of these various copolymers; Aqueous adhesives such as thermosetting synthetic resins such as melamine resin and urea resin; Acrylic acid such as polymethyl methacrylate Ester, methacrylic ester polymer or copolymer resin latex; polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, alkyd resin latex can be used, and one or more thereof can be used. Of these aqueous polymer binders, polyvinyl alcohol or polyvinyl alcohol derivatives such as silyl-modified polyvinyl alcohol are preferable from the viewpoint of adhesive strength.

  As a compounding quantity of a binder, it is 3-70 mass parts with respect to 100 mass parts of total with a white pigment, Preferably, it is 5-50 weight parts.

In the present invention, the dry coating amount of the ink receiving layer is not particularly limited, but if it is too small, the ink absorbency is good as in the case of the non-coated ink jet recording paper, but the image density, color, and sharpness are high. Low, the ink diffuses in the surface direction of the base paper, and the dot shape deterioration called feathering which is jagged in the shape of a bird feather occurs, and an image of good quality cannot be obtained. In addition, if the amount of dry coating is too large, the drying load in the drying process after coating or impregnation increases, and not only the productivity decreases due to the decrease in the coating or impregnation speed, but also in the case of drying at a high load, the ink Since the binder in the coating composition constituting the receiving layer moves to the surface of the ink receiving layer together with the solvent to evaporate, and the amount of voids on the surface is reduced, background staining or the like occurs during recording. Dry coating amount range 1 to 30 g / m ^2, more preferably from 4~20g / m ^2. By setting it within this range, the coating amount for controlling the gloss and curl balance of the backcoat layer can be adjusted, which is preferable.

  In the ink jet recording paper of the present invention, the ink receiving layer may have a multilayer structure, and a layer exhibiting gloss may be provided on the surface.

  In the present invention, the method for providing the ink receiving layer may be either an on-machine coater or an off-machine coater. For example, various devices such as conventionally known air knife coaters, curtain coaters, die coaters, blade coaters, gate roll coaters, bar coaters, rod coaters, roll coaters, bill blade coaters, short dwell blade coaters, cast coaters, and size presses are turned on. It can be used in a machine or off-machine.

  In the present invention, the method for drying after coating the ink-receiving layer is not particularly limited, and a known drying method can be used. In particular, drying is performed by heating such as a method of blowing hot air or a method of irradiating infrared rays. The method is preferably used with good productivity.

  In the present invention, after coating and drying the ink receiving layer, the ink receiving layer may be smoothed by cast treatment or calendar treatment for the purpose of controlling flattening or further increasing the surface gloss.

  In the present invention, the ink receiving layer and the backcoat layer can be formed in any order.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” and “%” indicate parts by mass and mass% unless otherwise specified.

<Support 1>
100 parts of wood pulp consisting of 70 parts of LBKP having a freeness of 450 ml CSF, 30 parts of NBKP having a freeness of 450 ml CSF, 5 parts of a pigment having a ratio of light calcium carbonate / heavy calcium carbonate / talc of 30/35/35, commercially available alkyl ketene dimer 0 .1 part, 0.03 part of commercially available cationic acrylamide, 1.0 part of commercially available cationized starch, and 0.5 part of sulfuric acid band were mixed with water to prepare a slurry, and then a basis weight of 157 g / Paper making was performed at m ² to obtain a support 1 which is a paper support having air permeability and ink solvent absorption.

<Support 2>
100 parts of LBKP was beaten to a freeness of 300 ml to prepare a pulp slurry. As a sizing agent, alkyl ketene dimer is 0.5% to pulp, polyacrylamide is 1.0% to pulp, cationized starch is 2.0% to pulp, and polyamide epichlorohydrin resin is used as a paper strength enhancer. 0.5% pulp was added and diluted with water to make a 0.1% slurry. This slurry is made with a long paper machine so as to have a basis weight of 170 g / m ² , a paper base is prepared, and further, a density of 0.918 g is formed on the surface of the paper base (side on which the pigment layer and the ink receiving layer are provided). A polyethylene resin composition in which anatase-type titanium dioxide is uniformly dispersed at a rate of 5% with respect to 100% low-density polyethylene / cm ³ resin is melted at 320 ° C. to a thickness of 20 μm at 200 m / min. After extrusion coating as described above, a support 2 that was a support having no air permeability and no ink solvent absorption was prepared by using a cooling roll that had been subjected to a fine-roughening treatment and having a surface glossiness of 60%.

<Backcoat layer coating solution 1>
100 parts of high white primary kaolin (average particle size 1.0 μm) and 0.25 part of 40% sodium polyacrylate dispersant were mixed with 100 parts of water using a sawtooth blade type stirrer. 21 parts of a 5% styrene-butadiene copolymer latex was mixed with 100 parts of a 5% phosphoric esterified starch aqueous solution to prepare a backcoat layer coating solution 1 having a solid content concentration of 35.9%.

<Backcoat layer coating solution 2>
100 parts of synthetic amorphous silica (average particle size: 4.0 μm) and 2.5 parts of 40% sodium polyacrylate dispersant were mixed with 400 parts of water using a saw-tooth blade type stirrer, and 50 parts thereof were mixed. 100 parts of a% polyurethane resin latex and 100 parts of a 5% phosphoric esterified starch aqueous solution were mixed to prepare a backcoat layer coating solution 2 having a solid content concentration of 22.2%.

<Backcoat layer coating solution 3>
100 parts of high white primary kaolin (average particle size 1.0 μm) and 0.25 part of 40% sodium polyacrylate dispersant were mixed with 100 parts of water using a sawtooth blade type stirrer. 100 parts of a 5% polyurethane resin latex and 100 parts of a 5% phosphoric esterified starch aqueous solution were mixed to prepare a backcoat layer coating solution 3 having a solid content concentration of 38.8%.

<Backcoat layer coating solution 4>
A sawtooth blade type stirrer containing 90 parts of high white primary kaolin (average particle diameter 1.0 μm), 10 parts of synthetic amorphous silica (average particle diameter 12 μm) and 1 part of 40% sodium polyacrylate dispersant. And mixed with 100 parts of water, 62.5 parts of 48% styrene-butadiene copolymer latex and 100 parts of 5% phosphoric esterified starch aqueous solution, and a backcoat layer having a solid content concentration of 37.2%. Coating solution 4 was prepared.

<Backcoat layer coating solution 5>
A sawtooth blade type stirrer containing 90 parts of high-white primary kaolin (average particle diameter 1.0 μm), 10 parts of acrylic organic spherical particles (average particle diameter 12 μm) and 1 part of 40% sodium polyacrylate dispersant. And mixed with 100 parts of water, 62.5 parts of 48% styrene-butadiene copolymer latex and 100 parts of 5% phosphoric esterified starch aqueous solution, and a backcoat layer having a solid content concentration of 37.2%. A coating solution 5 was prepared.

<Backcoat layer coating solution 6>
A sawtooth blade type stirrer containing 80 parts of high-white primary kaolin (average particle diameter 1.0 μm), 20 parts of acrylic organic spherical particles (average particle diameter 6 μm) and 1 part of 40% sodium polyacrylate dispersant. And mixed with 100 parts of water, 62.5 parts of 48% styrene-butadiene copolymer latex and 100 parts of 5% phosphoric esterified starch aqueous solution, and a backcoat layer having a solid content concentration of 37.2%. Coating liquid 6 was prepared.

<Backcoat layer coating solution 7>
A sawtooth blade type stirrer containing 90 parts of high-white primary kaolin (average particle diameter 1.0 μm), 10 parts of acrylic organic spherical particles (average particle diameter 6 μm) and 1 part of 40% sodium polyacrylate dispersant. And mixed with 100 parts of water, and 81.6 parts of 49% carboxylated styrene-butadiene copolymer latex and 100 parts of 5% phosphoric acid esterified starch aqueous solution are mixed with this to give a solid content concentration of 38.0%. A coating layer coating solution 7 was prepared.

<Backcoat layer coating solution 8>
45 parts of high-white primary kaolin (average particle size 1.0 μm), 63.4 parts of 71% heavy calcium carbonate slurry (average particle size 0.9 μm), 10 parts of acrylic organic spherical particles (average particle size 6 μm), 1 part of 40% sodium polyacrylate-based dispersant was mixed with 100 parts of water using a sawtooth blade type stirrer, and 81.6 parts of 49% carboxylated styrene-butadiene copolymer latex was added thereto. 100 parts of phosphoric esterified starch aqueous solution was mixed to prepare a backcoat layer coating solution 8 having a solid content concentration of 36.3%.

<Backcoat layer coating solution 9>
126.8 parts of 71% heavy calcium carbonate slurry (average particle diameter 0.9 μm) and 10 parts of acrylic organic spherical particles (average particle diameter 6 μm) were mixed with 100 parts of water using a sawtooth blade type stirrer. Then, 81.6 parts of 49% carboxylated styrene-butadiene copolymer latex was mixed with 100 parts of 5% phosphoric esterified starch aqueous solution to prepare a backcoat layer coating solution 9 having a solid content concentration of 34.7%. .

<Backcoat layer coating solution 10>
126.8 parts of 71% heavy calcium carbonate slurry (average particle size 0.9 μm) and 10 parts of spherical silica particles (average particle size 6.4 μm) were mixed with 100 parts of water using a sawtooth blade type stirrer. Then, 81.6 parts of 49% carboxylated styrene-butadiene copolymer latex was mixed with 100 parts of 5% phosphoric esterified starch aqueous solution to prepare a backcoat layer coating solution 10 having a solid content concentration of 34.7%. .

<Backcoat layer coating solution 11>
A sawtooth blade type stirrer containing 90 parts of high-white primary kaolin (average particle diameter 1.0 μm), 10 parts of acrylic organic spherical particles (average particle diameter 4 μm) and 1 part of 40% sodium polyacrylate dispersant. And mixed with 100 parts of water, 21 parts of 48% styrene-butadiene copolymer latex and 100 parts of 5% phosphoric esterified starch aqueous solution are mixed with this, and the backcoat layer coating solution with a solid content concentration of 35.9% is mixed. 11 was prepared.

<Backcoat layer coating solution 12>
A serrated blade-type stirrer containing 97 parts of high-white primary kaolin (average particle diameter 1.0 μm), 3 parts of acrylic organic spherical particles (average particle diameter 6 μm) and 1 part of 40% sodium polyacrylate dispersant. And mixed with 100 parts of water, 21 parts of 48% styrene-butadiene copolymer latex and 100 parts of 5% phosphoric esterified starch aqueous solution are mixed with this, and the backcoat layer coating solution with a solid content concentration of 35.9% is mixed. 12 was prepared.

<Ink-receiving layer coating solution 1>
100 parts of synthetic amorphous silica (Mizukasil P-78D: made by Mizusawa Chemical Industry Co., Ltd.) was mixed with 400 parts of water using a sawtooth blade type stirrer, and 10% polyvinyl alcohol aqueous solution (PVA117: made by Kuraray Co., Ltd.). ) 450 parts, 30% cationic dye fixing agent (Sumilet's Resin 1001: manufactured by Sumitomo Chemical Co., Ltd.) 100 parts were mixed to prepare an ink receiving layer coating solution 1 having a solid content concentration of 16.7%.

<Ink-receiving layer coating liquid 2>
100 parts of synthetic amorphous silica (Fine Seal X37B: manufactured by Tokuyama Corporation) was mixed with 480 parts of water using a sawtooth blade type stirrer, and 300 parts of a 10% polyvinyl alcohol aqueous solution (PVA117: manufactured by Kuraray Co., Ltd.). 100 parts of 30% cationic dye fixing agent (Sumilet's resin 1001: manufactured by Sumitomo Chemical Co., Ltd.) was mixed to prepare an ink-receiving layer coating liquid 2 having a solid content concentration of 16.3%.

<Ink-receiving layer coating solution 3>
To 400 parts of water, 2 parts of 60% nitric acid and 100 parts of alumina hydrate having a pseudo boehmite structure (average primary particle diameter 15 nm, specific surface area 160 m 2 / g by BET method) were added, and a sawtooth blade type stirrer was added. Used to make a 20.2% alumina hydrate dispersion. 502 parts of the alumina hydrate dispersion thus obtained, 10 parts of 4% boric acid aqueous solution, 100 parts of 8% polyvinyl alcohol (saponification degree 88%, average polymerization degree 3500), surfactant 0.3 parts, water 34 parts Were mixed to prepare an ink receiving layer coating solution 3 having a solid content concentration of 17.0%.

( Reference Example 1 )
The ink-receiving layer coating liquid 1 was coated on the support 1 produced above with an air knife coater so as to have a dry solid content of 11 g / m ² and dried with hot air. Next, after the back coating layer coating solution 3 was applied to the back surface of the support with an air knife coater so as to have a dry solid content of 7.5 g / m ² and dried by hot air, a soft calender treatment was performed, and Reference Example 1 Inkjet recording material was prepared. At this time, the thickness of the back coat layer was 7.0 μm.

(Example 1 )
Except for using the back-coat layer coating solution 4 instead of using a back coat layer coating solution 3 in Reference Example 1 was prepared inkjet recording material of Example 1 under the same conditions as in Reference Example 1. At this time, the thickness of the back coat layer was 7.1 μm.

(Example 2 )
An ink jet recording material of Example 2 was produced under the same conditions as in Reference Example 1 except that the backcoat layer coating solution 5 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 7.0 μm.

(Example 3 )
An inkjet recording material of Example 3 was produced under the same conditions as in Reference Example 1 except that the backcoat layer coating solution 6 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 6.9 μm.

(Example 4 )
An inkjet recording material of Example 4 was produced under the same conditions as in Reference Example 1 except that the backcoat layer coating solution 7 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 7.1 μm.

(Example 5 )
An ink jet recording material of Example 5 was produced under the same conditions as in Reference Example 1 except that the backcoat layer coating solution 8 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 6.9 μm.

(Example 6 )
An inkjet recording material of Example 6 was produced under the same conditions as Reference Example 1 except that the backcoat layer coating solution 9 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 6.7 μm.

(Example 7 )
An inkjet recording material of Example 7 was produced under the same conditions as in Reference Example 1 except that the backcoat layer coating solution 10 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 7.1 μm.

(Example 8 )
On the support 1 produced above, the ink receiving layer coating liquid 2 was applied with an air knife coater so as to have a dry solid content of 11 g / m ² and dried with hot air. On the ink receiving layer thus obtained, the ink receiving layer coating liquid 3 was further coated with an air knife coater so as to have a dry solid content of 8 g / m ² and dried with hot air. Further, the back coating layer coating solution 8 was applied on the back surface of the support with an air knife coater so as to have a dry solid content of 7.5 g / m ² , dried by hot air, and then subjected to soft calendering. Example 8 Inkjet recording material was prepared. At this time, the thickness of the back coat layer was 7.0 μm.

( Reference Example 2 )
The ink-receiving layer coating liquid 3 was applied on the support 2 prepared above with an air knife coater so as to have a dry solid content of 20 g / m ² and dried with hot air. Next, the back coating layer coating solution 3 was applied to the back surface of the support with an air knife coater so as to have a dry solid content of 7.5 g / m ² , dried by hot air, and then subjected to soft calendering. Reference Example 2 Inkjet recording material was prepared. At this time, the thickness of the back coat layer was 7.0 μm.

(Example 9 )
An inkjet recording material of Example 9 was produced under the same conditions as in Reference Example 1 except that the backcoat layer coating solution 11 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 6.9 μm.

(Example 10 )
Except for using the back-coat layer coating solution 12 in place of using a back coat layer coating solution 3 in Reference Example 1 was prepared inkjet recording material of Example 10 under the same conditions as in Reference Example 1. At this time, the thickness of the back coat layer was 6.8 μm.

( Reference Example 3 )
Except for using a back coat layer coating liquid 2 instead of using a back coat layer coating solution 3 in Reference Example 1 was prepared inkjet recording material of Example 3 under the same conditions as in Reference Example 1. At this time, the thickness of the back coat layer was 6.8 μm.

(Comparative Example 1)
An ink jet recording material of Comparative Example 1 was produced under the same conditions as Reference Example 1 except that the backcoat layer coating solution 1 was used instead of the backcoat layer coating solution 3 in Reference Example 1 . At this time, the thickness of the back coat layer was 7.0 μm.

<Evaluation>
The ink-jet recording materials produced in Examples 1 to 10, Reference Examples 1 to 3 and Comparative Example 1 were passed through PX-7500 manufactured by Seiko Epson Corporation, which is a printer having a surface uneven roll, and the gloss difference of the backcoat surface Generation | occurrence | production of was observed visually and evaluated by the numerical value of 1-5. 1 indicates that the gloss difference is most conspicuous, and as the value increases, the gloss difference decreases, and 5 indicates that no gloss difference is observed. The results are shown in “Visual Evaluation” in Table 1.

  The gloss difference before and after the abrasion resistance test of the back coat layer of the ink jet recording material was measured as a 75-degree specular gloss according to JIS-P8142, and the result is shown in “Gloss Difference” in Table 1.

  In the black cloth used for the abrasion resistance test, the portion where the coating layer of the backcoat layer was adhered and the portion where the coating layer was not adhered were measured using an optical densitometer (SpectroEye, manufactured by GretagMacbeth), and the results were measured. This is shown in “Density Difference” in Table 1.

In Table 1, as shown in Examples 1-10, a coating solution of the ink receiving layer is formed by coating and drying onto one side of the support, the surface opposite to the surface having the ink-receiving layer In the method for producing an ink jet recording material formed by coating and drying a backcoat layer coating solution containing at least a pigment and a binder, an inorganic pigment and a backcoat layer in addition to the inorganic pigment as the pigment of the backcoat layer A back coat layer coating solution containing particles having an average particle diameter of 0.5 to 2 times the thickness of the film and a latex is applied and dried, and the surface of the back coat layer is provided with an abrasion resistance test (JIS-P8136). ) By controlling the difference between the front and back 75-degree specular gloss (JIS-P8142) to 10 or less, the backcoat layer surface has a backcoat layer that does not cause gloss fluctuation when passing through an inkjet printer. Ink jet recording material manufacturing method.

  In Table 1, since Comparative Example 1 has a gloss difference of 10 or more, gloss fluctuations occur due to rubbing when the printer passes paper.

  Since the present invention forms a coating layer on the surface of the coating layer that does not cause gloss fluctuations upon contact with a roll or the like, the coated paper for printing, white paperboard, electrophotographic recording paper, inkjet paper, thermal paper, thermal paper, It can be used for coated paper such as pressure paper.

Schematic diagram of a paper feed mechanism in a general inkjet printer according to the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed roller 2 Drive roller 3 Driven roller 4 Platen 5 Recording head M Inkjet recording material

Claims (1)

A coating liquid for an ink-receiving layer formed on one side of a support by applying and drying, and a coating liquid for a backcoat layer containing at least a pigment and a binder on the surface opposite to the surface on which the ink-receiving layer is formed In the method for producing an ink jet recording material formed by coating and drying, the back coat layer surface has a difference in 75-degree specular gloss (JIS-P8142) before and after the abrasion resistance test (JIS-P8136) of 10 or less. , the coating and the back coating layer coating liquid containing particles and latex having an average particle diameter 0.5 to 2 times the thickness of the other in the back coat layer of the inorganic pigment and the inorganic pigment as a pigment of the backcoat layer A method for producing an ink jet recording material , comprising drying, providing, and controlling.

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