JP2015182402A - Inkjet recording paper sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording paper sheet excellent in cockling resistance, gloss feeling suppressing properties in a printing part and image sharpening properties.SOLUTION: The inkjet recording paper sheet having 5% or lower 85-degree surface glossiness comprises a substrate and an ink receptive layer on at least one surface of the substrate. A value obtained by dividing the Stockigt sizing degree (second) by the thickness (μm) of the substrate is 1.00 second/μm or larger and the density of the substrate is larger than 1.00 g/cm. The ink receptive layer contains silica having 9-12 μm average particle diameter, silanol-modified polyvinyl alcohol and an ethylene-vinyl acetate copolymer resin. The content mass ratio of the silanol-modified polyvinyl alcohol to the ethylene-vinyl acetate copolymer resin in the ink receptive layer is 6-14.

Description

  The present invention relates to an ink jet recording paper, and preferably relates to a matte ink jet recording paper having no gloss.

  Inkjet printers, inkjet large format printers, or inkjet large format plotters are used for printing photographed photographic data, printing designs and artworks, or printing for creating signboards and POPs.

  As a support for a recording medium used for printing, there are typically a film, a resin-coated paper (RC paper), and paper. As the support, a film or RC paper which is relatively excellent in image quality due to its smoothness is preferred. However, there are many cases in which ink jet recording paper using paper as a support is used due to the problem of handling of the recording medium, handling such as post-processing and disposal processing.

As a problem peculiar to inkjet recording paper using paper as a support, there is a paper waving phenomenon (cockling) due to moisture.
Ink jet recording is performed by discharging ink prepared by dissolving or dispersing a coloring material in a solvent such as water from a fine nozzle. In order to achieve high definition, high image quality, and high color density, on the ink side, methods such as increasing the number of colors of ink, decreasing the color material density in the ink, and increasing the amount of ink discharged are taken. These methods are in the direction of generating paper cockling.

  When the ink jet recording paper is likely to generate cockling, cockling is generated from a fold printed by a printer or a plotter, which causes poor paper conveyance in severe cases. Even if the conveyance is not defective, the distance between the nozzle and the paper is slightly deviated, which may cause a reduction in image sharpness. Further, even if little cockling is recognized after printing, if the cockling is temporarily during printing, image sharpness may be deteriorated.

As an ink jet recording sheet that is excellent in ink jet printing quality and hardly causes cockling, an ink receiving layer is provided on the surface of a support, and the ink receiving layer contains a silica pigment and an organic polymer adhesive, and The organic polymer adhesive contains polyvinyl alcohol and ethylene vinyl acetate polymer, and the blending ratio of (polyvinyl alcohol / ethylene vinyl acetate polymer) is in the range of 40/100 to 75/100 by mass ratio. And the compounding ratio of the silica-based pigment and the organic polymer adhesive is more than 28 parts by mass and less than 42 parts by mass with respect to 100 parts by mass of the silica-based pigment, and the inkjet recording sheet dry coating amount of the ink receiving layer is less than 20 g / m ² exceeds the per surface 5 g / m ² is known Some (for example, see Patent Document 1).

JP 2012-166351 A

  As a problem peculiar to a so-called mat-like ink jet recording paper having an 85 ° surface glossiness of 5% or less as defined in JIS Z8741: 1997, there is a variation in glossiness of the printed portion after printing. The “print section glossiness variation” is a phenomenon in which glossiness appears in a printing section that is in contact with a transport roll in the middle of transporting an inkjet printer, an inkjet large format printer, or an inkjet large format plotter. In the ink jet recording paper having a matte tone, the appearance of gloss in the printing part and the partial expression are problems in terms of quality after printing and appearance.

  The ink jet recording sheet as described in Patent Document 1 is excellent in coating surface quality, printing portion bleeding and density, but is required to further suppress occurrence of cockling. There is also a need for improvements in image sharpness and printed section glossiness variation.

  The occurrence of cockling is difficult to suppress unless it is improved not only from the structure of the ink receiving layer but also from the support on which the ink receiving layer is provided.

  An object of the present invention is a so-called mat-like ink jet recording paper having an 85 degree surface glossiness of 5% or less as defined in JIS Z8741: 1997, and can satisfactorily suppress the occurrence of cockling (anti-resistance). The present invention is to provide an ink jet recording paper that can satisfactorily suppress variation in cockling property and glossiness of the printed part (printing part glossiness suppression property) and has good image sharpness.

The above object of the present invention is to provide an inkjet recording paper having an 85 ° surface glossiness of 5% or less as defined in JIS Z8741: 1997, and having a support and an ink receiving layer on at least one side of the support. , The value obtained by dividing the degree of sizing (seconds) measured according to JIS P8122: 2004 by the thickness (μm) of the support is 1.00 seconds / μm or more, and The ink receiving layer contains a silica having a density greater than 1.00 g / cm ³ and an average particle diameter of 9 μm or more and 12 μm or less, silanol-modified polyvinyl alcohol, and ethylene-vinyl acetate copolymer resin. An ink jet having a silanol-modified polyvinyl alcohol content mass ratio of 6 to 14 with respect to the vinyl acetate copolymer resin. It is achieved by the door recording paper.

  According to the present invention, a mat-like ink jet recording paper having an 85 ° surface glossiness of 5% or less as defined in JIS Z8741: 1997, has excellent cockling resistance, print portion glossiness suppression and image sharpness. Inkjet recording paper can be provided.

  Hereinafter, the ink jet recording paper of the present invention will be described in detail.

  The support of the present invention mainly comprises wood pulp conventionally known in the papermaking field such as chemical pulp such as LBKP and NBKP, mechanical pulp such as GP, PGW, RMP, TMP, CTMP, CMP and CGP, and waste paper pulp such as DIP. As a component, a paper stock containing various additives conventionally known in the papermaking field such as fillers, binders, sizing agents, fixing agents, yield improvers, cationizing agents, paper strength enhancing agents, etc., as required Coated paper with base paper produced by various machines such as a paper machine, circular paper machine, twin wire paper machine, etc., and high-quality paper size-pressed with starch, polyvinyl alcohol, etc., or an anchor coat layer. Is included.

In the present invention, the support has a value obtained by dividing the Steecht sizing degree (seconds) measured in accordance with JIS P8122: 2004 by the thickness (μm), and the density is 1.00 seconds / μm or more. More than 1.00 g / cm ³ . By using the support in these ranges and the ink receiving layer described later, the ink jet recording paper can obtain excellent cockling resistance, print section glossiness suppression and image sharpness. If the support does not fall within these ranges, any of the effects of the present invention cannot be obtained satisfactorily. From the standpoint of image sharpness and printed part glossiness suppression, the value obtained by dividing the Steecht sizing degree (seconds) by the thickness (μm) is preferably 1.35 seconds / μm or less. The density is preferably 1.15 g / cm ³ or less from the viewpoint of suppressing the glossiness of the printed part.

  A support in these ranges can be obtained by a conventionally known method in the papermaking field. For example, a method of blending a sizing agent into a paper stock, a method of size pressing with a liquid containing a surface sizing agent, a method of blending a filler into a paper stock, and calendar processing with a calendar device such as a machine calendar, TG calendar, or soft calendar. The method of doing can be mentioned.

  From the above relationship, the support of the present invention preferably has a tendency that it has a large steecht size, a small thickness, and a high density. Although it is considered that cockling resistance is adversely affected when the thickness is thin or the density is large, the present invention has found such a range in the effect of the present invention depending on the degree of Steecht sizing and the relationship between the thickness and the density. is there.

In the present invention, the ink jet recording paper has an ink receiving layer on at least one side of the support. The coating amount per side of the ink receiving layer is not particularly limited, but is preferably 5 g / m ² or more and 15 g / m ² or less, and more preferably 7 g / m ² or more and 10 g / m ² or less in terms of dry solid content. This is because when the coating amount is within the above range, the occurrence of curling after printing on the inkjet recording paper is reduced.

  In the present invention, the ink receiving layer contains silica having an average particle diameter of 9 μm or more and 12 μm or less. When the average particle diameter is less than 9 μm, the ink jet recording paper cannot obtain good print section glossiness suppression. When the average particle size is more than 12 μm, the ink jet recording paper cannot obtain good cockling resistance and image sharpness.

  In the present invention, the silica is wet process silica or gas phase process silica depending on the production method. Further, the wet process silica is classified into a precipitation process silica and a gel process silica according to the production method. In the present invention, wet process silica is preferred. Here, the silica according to the present invention does not include the sol method silica.

  Precipitated silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions. The silica particles that have grown are agglomerated and settled, and then processed through filtration, washing, drying, pulverization and classification. The secondary particles of silica produced by this method become loose agglomerated particles, and particles that are relatively easy to grind are obtained. Precipitated silica is commercially available, for example, as Carplex from Evonik Degussa, as Mizusukasil from Mizusawa Chemical, and as a nip seal from Tosoh Silica.

  Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During aging, the microparticles dissolve and reprecipitate so as to bind the other primary particles, so that the distinct primary particles disappear and form relatively hard aggregated particles having an internal void structure. The gel method silica is commercially available, for example, as Carplex from Evonik Degussa, as Mizusukasil from Mizusawa Chemical, as nip gel from Tosoh Silica, as syloid and silojet from Grace Japan.

  Vapor phase process silica is also called dry process with respect to wet process silica, and is generally manufactured using flame hydrolysis. Specifically, a method of making silicon tetrachloride by burning with hydrogen and oxygen is generally known, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone or silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state. Vapor phase silica is commercially available from Nippon Aerosil as Aerosil, and from Tokuyama as Leolosil.

  In the present invention, the average particle size is the average particle size of single particles when present as single particles, and the average particle size of aggregated particles when forming aggregated particles such as secondary particles. An average particle diameter can be calculated | required from the state used as the coated paper. As the method, for example, a scanning electron microscope with an element analysis function such as an energy dispersive X-ray spectrometer is used to take an electron micrograph of the surface of an ink jet recording paper, and a spherical shape whose area approximates the photographed particles. This is a method of calculating the average particle size by calculating the particle size and measuring particles from 100 particles present in the photographed image.

  In the present invention, the ink receiving layer can contain a conventionally known pigment in the papermaking field in addition to the above silica, as long as the effects of the present invention are not impaired. Examples of pigments include alumina hydrate, alumina, light calcium carbonate, heavy calcium carbonate, satin white, clay, talc, titanium oxide, kaolin, calcined kaolin, zinc oxide, activated clay, diatomaceous earth, lake, plastic pigment, etc. Can be mentioned.

  In the present invention, the ink receiving layer contains silanol-modified polyvinyl alcohol and ethylene-vinyl acetate copolymer resin. In addition, the content ratio of the silanol-modified polyvinyl alcohol to the ethylene-vinyl acetate copolymer resin in the ink receiving layer is 6 or more and 14 or less. By satisfying these requirements, the ink jet recording paper can obtain excellent cockling resistance, print section glossiness suppression and image sharpness. If these are not satisfied, any of the effects of the present invention cannot be obtained satisfactorily.

  In the present invention, a water-dispersible binder and / or a water-soluble binder conventionally known in the papermaking field as a binder other than the above-mentioned silanol-modified polyvinyl alcohol and ethylene-vinyl acetate copolymer resin, as long as the effects of the present invention are not impaired. can do. Examples of the water dispersible binder include conjugated diene copolymer latex such as styrene-butadiene copolymer or acrylonitrile-butadiene copolymer, acrylate ester or methacrylate ester polymer, or methyl methacrylate-butadiene copolymer. Acrylic copolymer latex, vinyl copolymer latex such as vinyl chloride-vinyl acetate copolymer, polyurethane resin latex, alkyd resin latex, unsaturated polyester resin latex, or carboxyl groups of these various copolymers Examples thereof include functional group-modified copolymer latex with functional group-containing monomers such as thermosetting synthetic resins such as melamine resin and urea resin. Examples of the water-soluble binder include starch derivatives such as oxidized starch, etherified starch, and phosphate esterified starch, cellulose derivatives such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose, polyvinyl alcohol excluding silanol-modified polyvinyl alcohol, and modified products thereof. Polyvinyl alcohol derivatives, casein, gelatin or modified products thereof, soy protein, pullulan, gum arabic, Karaya gum, albumin and other natural polymer resins or derivatives thereof, vinyl polymers such as sodium polyacrylate, polyacrylamide, polyvinylpyrrolidone , Sodium alginate, polypropylene glycol, polyethylene glycol, maleic anhydride or a copolymer thereof.

  In the present invention, the total content of the silanol-modified polyvinyl alcohol, the ethylene-vinyl acetate copolymer resin and the other binder in the ink receiving layer is 30 to 40 parts by weight with respect to 100 parts by weight of the pigment in the ink receiving layer. A range is preferred. This is because the ink absorbability of the ink jet recording paper is improved.

  The ink receiving layer of the present invention can contain a cationic resin and / or a water-soluble polyvalent metal salt as an ink fixing agent. The cationic resin and the polyvalent metal salt can be used alone or in combination of two or more. Moreover, it is preferable to use together a cationic resin and a polyvalent metal salt.

  In the present invention, the cationic resin is a commonly used cationic polymer or cationic oligomer. Preferred cationic resins are polymers or oligomers containing primary to tertiary amines or quaternary ammonium salts that readily coordinate with protons and dissociate when dissolved in water to exhibit cationic properties. Specific examples include, for example, polyethyleneimine, polyvinyl pyridine, polyvinyl amidine, polyamine sulfone, polydialkylaminoethyl methacrylate, polydialkylaminoethyl acrylate, polydialkylaminoethyl methacrylamide, polydialkylaminoethyl acrylamide, polyepoxyamine, polyamidoamine. , Dicyandiamide-formalin condensate, compounds such as polyvinylamine, polyallylamine and their hydrochlorides, and polydiallyldimethylammonium chloride and copolymers of diallyldimethylammonium chloride and acrylamide, polydiallylmethylamine hydrochloride, polyamine- Examples thereof include, but are not limited to, epihalohydrin polycondensates.

In the present invention, the water-soluble polyvalent metal salt refers to a salt containing a polyvalent metal ion that can be dissolved in water at 20 ° C. in an amount of 1% by mass or more. Examples of the polyvalent metal ions include divalent metal ions such as magnesium, calcium, strontium, barium, nickel, zinc, copper, iron, cobalt, tin, and manganese, trivalent metal ions such as aluminum, iron, and chromium, or Tetravalent metal ions such as titanium and zirconium, and complex ions thereof. The anion that forms a salt with the polyvalent metal ion may be either an inorganic acid or an organic acid, and is not particularly limited. Examples of inorganic acids include, but are not limited to, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, hydrofluoric acid, and the like. Examples of the organic acid include, but are not limited to, formic acid, acetic acid, lactic acid, citric acid, oxalic acid, succinic acid, and organic sulfonic acid.
Also included in the water-soluble polyvalent metal salt are polyaluminum chloride obtained by dissolving aluminum hydroxide in hydrochloric acid and causing a polymerization reaction.

  The content in the ink receiving layer is 10 to 30 parts by weight of the cationic resin and 2 to 10 parts by weight of the water-soluble polyvalent metal salt with respect to 100 parts by weight of the pigment in the ink receiving layer. The following is preferable. This is because not only ink fixability can be obtained, but also the adverse effect of the ink fixing agent on the cockling resistance and the print section glossiness suppression can be avoided. Moreover, it is because the coloring property of an image becomes favorable.

  The ink-receiving layer of the present invention is optionally added with various additives commonly used in the papermaking field, such as pigment dispersants, thickeners, fluidity improvers, antifoaming agents, antifoaming agents, and mold release agents. An agent, a foaming agent, a penetrating agent, an ultraviolet absorber, an antioxidant, an antiseptic, a batter-proofing agent, a water resistant agent, a paper strength enhancing agent, and the like can be appropriately contained.

  In the present invention, examples of the method of providing the ink receiving layer on the support include, for example, a method in which the ink receiving layer coating solution is applied by an on-machine coater or an off-machine coater using various conventionally known coating apparatuses. it can. Examples of conventionally known coating apparatuses include 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. And so on. Moreover, you may perform a calendar process by a machine calendar, a TG calendar, a super calendar, a soft calendar, etc. for the finishing after coating.

  Moreover, drying can be implemented as finish after coating using conventionally well-known drying apparatuses, such as a hot air drying apparatus.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Moreover, the mass part and mass% shown in the Examples indicate the values of dry solid content or substantial components. Further, the coating amount indicates a value of dry solid content.

<Evaluation of cockling resistance>
A black solid was printed with a Canon inkjet printer “ImagePROGRAF iPF610”, and the degree of cockling in the printed portion was visually evaluated in the following four stages. In the present invention, if the evaluation is 3 or 4, the ink jet recording paper has good cockling resistance.
4: Very good level with no cockling.
3: Occurrence of cockling is slight and good level.
2: Occurrence of cockling is observed, which is not good and is a practical lower limit level.
1: The level at which cockling occurs and becomes a practical problem.

<Evaluation of image sharpness>
Print out a predetermined evaluation image with Canon's inkjet printer “ImagePROGRAF iPF610” and use it to determine the sharpness of the extracted characters placed in the solid image area of black, cyan, magenta, and yellow and the sharpness of the boundary between colors. Then, sensory evaluation was performed in the following four stages. In the present invention, if the evaluation is 3 or 4, the inkjet recording paper has good image sharpness.
4: Very good level.
3: Inferior to the above “4” but good level.
2: It is inferior to the above “3” and is not good and is a practical lower limit level.
1: A level that is inferior to the above-mentioned “2” and causes a practical problem.

<Evaluation of print section glossiness suppression>
A black solid was printed with an inkjet printer “ImagePROGRAF iPF610” manufactured by Canon Inc., and the gloss unevenness of the printed portion was subjected to sensory evaluation in the following four stages. In the present invention, if the evaluation is 3 or 4, it is assumed that the ink jet recording paper has good gloss suppression of the printed part.
4: The glossiness of the printed part cannot be recognized, and the level is very good.
3: Although the printed part glossiness can be recognized slightly, it is a good level.
2: The printed part glossiness is somewhat recognized, and it is not good, and is a practical lower limit level.
1: A level in which the glossiness of the printed part is recognized and becomes a problem in practical use.

<Production of support>
LBKP (hardwood bleached kraft pulp) was beaten to 350 ml with Canadian Standard Freeness to obtain a pulp slurry. This is combined with calcium carbonate as filler, alkyl ketene dimer as sizing agent, polyacrylamide, cationized starch and polyamide epichlorohydrin resin as paper strength enhancer, and diluted with water to prepare 1% by weight paper stock. did. This stock was made with a long paper machine, dried and conditioned, and then calendered with a machine calendar to prepare a support. At this time, the blending amount of the sizing agent and the calendering conditions were mainly adjusted so as to finally obtain a desired steecht sizing degree, thickness, and density. The obtained support is shown below.

<Support 1>
Steecht size 127 seconds, paper thickness 117 μm, density 1.03 g / cm ³
<Support 2>
Steecht size 150 seconds, paper thickness 113 μm, density 1.06 g / cm ³
<Support 3>
Steecht size 75 seconds, paper thickness 117 μm, density 0.77 g / cm ³
<Support 4>
Steecht size 120 seconds, paper thickness 117 μm, density 0.77 g / cm ³
<Support 5>
Steecht size 127 seconds, paper thickness 113 μm, density 1.15 g / cm ³
<Support 6>
Steecht size 150 seconds, paper thickness 110 μm, density 1.20 g / cm ³
<Support 7>
Stekihito size 110 seconds, paper thickness 117 μm, density 1.04 g / cm ³

<Preparation of ink receiving layer coating liquid 1>
100 parts by weight of silica (Carplex BS-510BX manufactured by Evonik Degussa, average particle diameter of 10.5 μm) was added to water, and the mixture was sufficiently dispersed using a disperser having a saw blade. Next, 30 parts by mass of silanol-modified polyvinyl alcohol (R polymer 1130 manufactured by Kuraray Co., Ltd.) and 5 parts by mass of ethylene-vinyl acetate copolymer resin (Rikabond BEF-9857 manufactured by Chuo Rika Kogyo Co., Ltd.) were added and stirred, and then polyamine-epihalohydrin heavy Add 10 parts by weight of condensate (Magnafloc LT7990 manufactured by BASF), 10 parts by weight of polyvinylamidine (Himax SC-700M manufactured by Hymo Co.), and 3 parts by weight of calcium chloride dihydrate. A working liquid 1 was prepared.

<Preparation of ink receiving layer coating liquid 2>
Ink-receiving layer coating was the same as ink-receiving layer coating solution 1 except that 33 parts by weight of silanol-modified polyvinyl alcohol and 3.5 parts by weight of ethylene-vinyl acetate copolymer resin were used in ink-receiving layer coating liquid 1. A working fluid 2 was prepared.

<Preparation of ink receiving layer coating solution 3>
Ink-receiving layer coating was the same as ink-receiving layer coating solution 1 except that 35 parts by weight of silanol-modified polyvinyl alcohol and 2.5 parts by weight of ethylene-vinyl acetate copolymer resin were used in ink-receiving layer coating liquid 1. A working liquid 3 was prepared.

<Preparation of ink receiving layer coating solution 4>
Except for changing the silica (Evonik Degussa Carplex BS-510BX, average particle size 10.5 μm) of the ink-receiving layer coating liquid 2 to silica (Mizusawa Chemical Co., Ltd. Mizukasil P-78D, average particle size 12 μm). Prepared an ink receiving layer coating solution 4 in the same manner as the ink receiving layer coating solution 2.

<Preparation of ink receiving layer coating solution 5>
Ink-receiving layer except that silica (Evonik Degussa Carplex BS-510BX, average particle size 10.5 μm) in the ink-receiving layer coating liquid 2 was changed to silica (Grace Japan, Psyroid ED5, average particle size 9 μm). In the same manner as the coating liquid 2, an ink receiving layer coating liquid 5 was prepared.

<Preparation of ink receiving layer coating liquid 6>
Ink-receiving layer coating solution was the same as ink-receiving layer coating solution 1, except that 30 parts by mass of silanol-modified polyvinyl alcohol and 7.25 parts by mass of ethylene-vinyl acetate copolymer resin were used. A working fluid 6 was prepared.

<Preparation of ink receiving layer coating solution 7>
Ink-receiving layer coating was carried out in the same manner as ink-receiving layer coating solution 1, except that 32 parts by mass of silanol-modified polyvinyl alcohol and 1.8 parts by mass of ethylene-vinyl acetate copolymer resin were used. A working liquid 7 was prepared.

<Preparation of ink receiving layer coating liquid 8>
An ink receiving layer coating solution 8 was prepared in the same manner as the ink receiving layer coating solution 3 except that 0 part by mass of the ethylene-vinyl acetate copolymer resin of the ink receiving layer coating solution 3 was used.

<Preparation of ink receiving layer coating liquid 9>
An ink receiving layer coating solution 9 was prepared in the same manner as the ink receiving layer coating solution 8, except that the silanol-modified polyvinyl alcohol of the ink receiving layer coating solution 8 was changed to polyvinyl alcohol (PVA235 manufactured by Kuraray Co., Ltd.).

<Preparation of ink receiving layer coating solution 10>
Ink-accepting except that silica (Evonik Degussa Carplex BS-510BX, average particle size 10.5 μm) in the ink-receiving layer coating solution 2 was changed to silica (Grace Japan Silojet P508, average particle size 8 μm). In the same manner as the layer coating solution 2, an ink receiving layer coating solution 10 was prepared.

<Preparation of Ink Receiving Layer Coating Liquid 11>
Ink except that silica (Evonik Degussa Carplex BS-510BX, average particle size 10.5 μm) in the ink-receiving layer coating liquid 2 was changed to silica (Mizusawa Chemical Mizukasil P-78F: average particle size 18 μm). Ink receiving layer coating solution 11 was prepared in the same manner as receiving layer coating solution 2.

<Preparation of ink receiving layer coating liquid 12>
Ink-receiving layer coating was carried out in the same manner as ink-receiving layer coating solution 1, except that silanol-modified polyvinyl alcohol (R polymer 1130 manufactured by Kuraray Co., Ltd.) of ink-receiving layer coating solution 1 was changed to polyvinyl alcohol (PVA235 manufactured by Kuraray Co., Ltd.). A working liquid 12 was prepared.

<Preparation of inkjet recording paper>
The ink receiving layer coating solution is coated on a support using an air knife coater so that the coating amount is 9 g / m ² , dried using a hot air dryer, and the resulting coated paper is softened. The calendar process was given with the calendar | calender and the inkjet recording paper of each Example and each comparative example was produced.

  Table 1 shows the support used, the value and density of “Stechite sizing / thickness” of the support, the ink-receiving layer coating solution used, the average particle diameter of silica in the ink-receiving layer, and “silanol-modified polyvinyl alcohol. Content ratio of “/ ethylene-vinyl acetate copolymer resin” and each evaluation result are shown. In addition, the 85 degree surface glossiness prescribed | regulated by JISZ8741: 1997 of the inkjet recording paper of each Example and each comparative example was all 5% or less.

  From Table 1, it can be seen that each example corresponding to the present invention has good cockling resistance, print portion glossiness suppression, and image sharpness. On the other hand, it is understood that any one of these comparative examples not satisfying the configuration of the present invention is not good.

Claims (1)

An ink jet recording paper having an 85 ° surface glossiness of 5% or less as defined in JIS Z8741: 1997 has a support and an ink receiving layer on at least one side of the support, and JIS P8122: 2004 of the support. The value obtained by dividing the Steecht sizing degree (seconds) measured in accordance with the above by the thickness (μm) of the support is 1.00 seconds / μm or more, and the density of the support is 1.00 g / cm ^3. The ink receiving layer contains silica having an average particle size of 9 μm or more and 12 μm or less, silanol-modified polyvinyl alcohol, and ethylene-vinyl acetate copolymer resin, and silanol modification to the ethylene-vinyl acetate copolymer resin in the ink receiving layer. An inkjet recording paper, wherein the content ratio of polyvinyl alcohol is 6 or more and 14 or less.