JP2002194698A - Matte coated paper for offset printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-density matte coated paper having opacity and stiffness suitable for a practical use and having high ink impressibility and printing glossiness in spite of having low white paper glossiness in the matte coated paper for offset printing. SOLUTION: This matte coated paper for the offset printing comprises a delaminated clay having 3.5-20μm volume-distributed mean particle diameter as a pigment in an mount of 30-90 pts.wt. based on 100 pts.wt. of the total pigment, has <30% white paper glossiness, <=0.95 g/cm3 coated paper density, and >=150 s smoothness in the matte coated paper for the offset printing formed by installing a coated layer comprising the pigment and an adhesive on a base paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matte coated paper for offset printing which has excellent printability in spite of low glossiness of white paper.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for high-quality coated printing papers that can strongly convey the contents visually by using many photographs and designs and further coloring the printed matter.
On the other hand, there is a strong demand for reducing the weight of printed materials in terms of resource saving, transportation and mailing costs. These two demands are contradictory, and high-quality print-coated paper has a large amount of base paper and coating amount, and is smoothed by surface treatment.
Since the density is higher than that of the same grammage, it does not meet the demand for weight reduction. To reduce the weight of the printed matter, it is possible to select a paper having a low basis weight. However, if the density is the same, the paper thickness decreases with the weight reduction, and the volume feeling of the booklet is deteriorated. For this reason, a coating having a higher paper thickness as compared with the same basis weight or a lower basis weight as compared with the same paper thickness, that is, having a low density (bulk) and good printability such as ink adhesion. Paper is required.

[0003] Coated papers are broadly classified into glossy coated papers and matte coated papers. The glossy coated paper includes art paper, super art paper, and coated paper used for catalogs, pamphlets, and the like, which have been conventionally used for high-grade printing, and the print finish is glossy in which both white paper gloss and print gloss are high. The matte coated paper has a dull tone and a matte tone, and has lower white gloss and printed gloss than gloss gloss. The matte tone has lower blank gloss than the dull tone. In particular, matte matte coated paper is easier to read the character portion after printing than conventional glossy coated paper, and the demand has been increasing in recent years.

For example, 157 g of basis weight as mat coated paper
/ M ^2, both surfaces coating amount 30 to 50 g / m ^2, a density (bulk density) 0.
Typical quality of 88 g / cm ³ mat coated paper is 75 g
° Gloss 12%, 60 ° Gloss 27% (4 color overprint)
(Printing and paper 188 pages Paper Industry Times
1996). In an attempt to reduce the weight of this matte matte coated paper, for example, when the base paper basis weight and the coating weight of the mat coated paper are reduced to half and the total basis weight is 80 g / m ² , the printing gloss is significantly reduced. In addition, the opacity is reduced and the problem of show-through is increased. If the coating weight of the coating layer is increased in order to improve the printing gloss while maintaining the total grammage of 80 g / m ^2, the basis weight of the base paper must be reduced by that much, and the opacity and rigidity are further increased. Lack and impractical. By increasing the basis weight of the base paper to improve the opacity and rigidity to a practical level, if the coating amount is extremely reduced this time, the surface coverage will be insufficient and the printing gloss will be extremely low. The result is a low, unclear image. As a method of improving the opacity, a method of internally adding an inorganic filler such as titanium dioxide having high opacity to the base paper is known, but when the inorganic filler is internally added, the density of the base paper is increased. .

On the other hand, in order to improve the print quality of coated paper, especially the density of ink deposition and the print glossiness of the image area, it is effective means to improve the smoothness of the coated paper. . For this reason, it is common to apply a surface smoothing treatment such as a super calender to glossy coated paper or coated paper with a white glossiness between the matte coated paper and gloss coated paper called dull tone. It is a target. However, since these treatments increase the smoothness of the surface by pressing the paper, the glossiness of the white paper is high, the paper thickness of the paper is low, and it is not enough to obtain the target print quality. .

As a method for reducing the weight of base paper while maintaining the paper thickness and opacity at a low density, a method of blending a hollow synthetic organic material capsule, a synthetic organic foaming filler foamed by the heat of a dryer during papermaking (for example, a commercial product) Name EXPANCEL,
A method of blending Nippon Philite Co., Ltd.) is known. However, it is difficult to obtain stable operating conditions such as drying conditions during papermaking, and these methods are not suitable for varieties requiring mass production. Also, although not a filler, a method of adding finely fibrillated cellulose has been proposed in JP-A-8-13380. However, in this method, it is necessary to separately adjust the fine fibrillated cellulose, the operation becomes complicated, and it is not practical.

As described above, it is not possible to obtain a light-weight matte matte coated paper having desired characteristics by simply applying the conventional technology.

[0008]

In view of such circumstances, an object of the present invention is to provide a low-density opacity suitable for practical use,
An object of the present invention is to provide a matte matte coated paper having rigidity and high ink deposition and printing gloss despite low blank gloss.

[0009]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that a matte coated paper for offset printing comprising a base paper provided with a coating layer containing a pigment and an adhesive, The pigment has a volume distribution average particle size of 3.5 to 3.5.
20 to 90 parts by weight of a delaminated clay per 100 parts by weight of a pigment and a white paper gloss of 30
%, Smoothness is 150 seconds or more, and coated paper density is 0.95
g / cm ³ or less, preferably 0.90 g / cm ³ or less, has a low density and a paper thickness even at a low basis weight, has opacity and rigidity suitable for practical use, and has a low white paper gloss. ,
It was possible to obtain an image having relatively good ink inking property and high printing glossiness, and it was found that the above-mentioned problems were solved.

As the coating pigment, a delaminated clay having a volume distribution average particle size of 3.5 to 20 μm is used.
It is important to add ~ 90 parts by weight. In the present invention, the delaminated clay obtained by peeling the ordinary clay in which hexagonal plates are laminated into a single layer (delamination) is used as a pigment, so that a large particle-shaped plate is formed on the surface of the coating layer. Is easily oriented, so that even when coated on a base paper having a high porosity with a relatively low coating amount, the base paper coatability becomes good, smoothness is easily obtained, and ink deposition and printing are performed. It is possible to obtain an image with high gloss. In addition, since the base paper has good coverability, it can be processed under a lower pressure condition than ordinary calendering, and can have low density, improved opacity and rigidity.

[0011] The delaminated clay of the present invention is characterized by a particle size distribution, and has a relatively large particle size distribution which is larger than that of a normal type, so that the base paper coatability is improved. However, when compared at the same coating amount, the effective coating layer thickness contributing to printability is increased, the printing gloss is also increased, and the white paper gloss is low at less than 30% at a low coating amount. It is considered that relatively high ink inking property and printing glossiness can be obtained. In order to further improve the coating aptitude of coating and the quality of coated paper, a delaminated clay having a volume distribution average particle diameter of 3.5 to 20 μm is used for 55 to 9 μm.
It is preferable to add 0 parts by weight.

When a delaminated clay having an average particle size of less than 3.5 μm is used, the glossiness of white paper is relatively high, the printing gloss is low, and the suitability for offset printing is poor.
When a delaminated clay having an average particle size of more than 20 μm is used, the viscosity of the coating liquid increases in the production of a coated paper in which the coating liquid is applied to the base paper, and handling during preparation of the coating liquid is difficult. Coating defects such as scratching, bleeding, etc. occur, which causes operational problems. The average particle size defined in the present invention is a value obtained by using a laser diffraction method, and is a value obtained by measuring a volume distribution average particle size using a Laser Diffraction particle size distribution analyzer manufactured by MALVERN Instruments.

The pigment has a volume distribution average particle size of 3.5.
Even when a delaminated clay having a thickness of ２０20 μm is blended, if the blending amount is less than 30 parts by weight with respect to 100 parts by weight of the pigment, the base paper coatability is relatively poor and the offset printing suitability is poor. If the compounding amount is 90 parts by weight or more, the ink setting property during offset printing becomes extremely slow. When the ink setting property is extremely slow, when multicolor printing is performed, the second color is printed before the tack of the first printing ink on the coated paper increases, and 1
A phenomenon occurs in which the color ink is carried, resulting in printing trouble.

In the present invention, the glossiness of the matte coated paper is less than 30%, more preferably less than 25%. Matte coated paper is a flat and calm printed matter, and the printed character portion is easier to read than a conventional glossy paper, and the demand has been increasing in recent years. Blank paper gloss of 30
%, The printed characters are difficult to read. Also,
The density of the coated paper is 0.95 g / cm ³ or less, more preferably 0.90 g / cm ³ or less. Coated paper density 0.9
If it exceeds 5 g / cm ³ , the paper thickness will be low and the opacity will be low, and the risk of set-off problems will increase. The smoothness of the coated paper is preferably 150 seconds or more, more preferably 200 seconds or more. Smoothness is 1
If the time is less than 50 seconds, uneven transfer of ink occurs during printing, and good ink inking property and print surface feeling cannot be obtained, and it is difficult to reproduce a fine print image portion. In addition, the smoothness specified in the present invention refers to JAPAN TAPPI paper pulp test method NO. 5 This is a value measured in accordance with “Testing method for smoothness and air permeability of paper and paperboard using an air micrometer type tester”.

In the present invention, as a filler for the coated base paper, amorphous silicate is preferably contained in an amount of 3 to 12% by weight based on the weight of the base paper in order to increase the opacity at a lower density and maintain the surface strength. What is amorphous silicate?
Any insoluble silicate may be used, and examples include hydrous aluminum silicate, hydrous aluminum silicate soda, hydrous calcium silicate, and hydrous magnesium silicate.

Further, in the present invention, since the ink has low density and opacity suitable for practical use, and has high ink inking property and print gloss despite low glossiness of white paper, the pigment is added to the base paper for coating. After coating and drying a coating liquid containing an adhesive, it is preferable to press-finish with a high-temperature soft nip calender having a rigid roll temperature of 100 ° C. or more, and more preferably 1
50 ° C. or higher. A metal roll is preferable as the rigid roll.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a pigment used in the present invention, 30 to 90 parts by weight of a delaminated clay having a volume distribution average particle size of 3.5 to 20 .mu.m is used, provided that the object of the invention is not impaired. Other pigments can be used in combination. As other pigments, conventionally used for coated paper, kaolin, clay, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate,
Inorganic pigments such as calcium sulfate, zinc oxide, silicic acid, silicate, colloidal silica, and satin white; and organic pigments such as plastic pigments. These pigments can be used alone or in combination of two or more as needed.

As the adhesive used in the present invention, styrene / butadiene type, styrene / acrylic type, ethylene / vinyl acetate type, which has been conventionally used for coated paper, may be used.
Various adhesives such as butadiene / methyl methacrylate and vinyl acetate / butyl acrylate, or synthetic adhesives such as polyvinyl alcohol, maleic anhydride copolymer and acrylic acid / methyl methacrylate copolymer; casein, soy protein, Proteins such as synthetic proteins; oxidized starch, positive starch, etherified starch such as urea phosphorylated ester, hydroxyethyl etherified starch, starches such as dextrin; cellulose derivatives such as carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, etc. One or more ordinary adhesives for coated paper are appropriately selected and used. These adhesives are pigment 1
5 to 50 parts by weight, more preferably 10 to 100 parts by weight
It is used in a range of about 30 parts by weight. In the present invention, it is preferable to mix starch as an adhesive in an amount of 6 parts by weight or more per 100 parts by weight of the pigment. The present invention relates to a low-density coated paper, for which it is necessary to coat a low-density base paper. In low-density base paper, since the base paper is porous, the coating material generally penetrates into the base paper, and the base paper coatability tends to decrease. Therefore, the coverage of the coating layer is improved by blending 6 parts or more of starch having good water retention compared to a binder such as latex. It is also effective to mix various natural and synthetic water retention agents as a technique for improving water retention.

The coating liquid of the present invention may contain various commonly used auxiliaries such as a dispersant, a thickener, a water retention agent, an antifoaming agent, and a waterproofing agent.

As the base paper for coating, a paper base or paperboard base paper having a basis weight of about 30 to 400 g / m ² used for general coated paper is appropriately used. A lower density coated base paper is used to obtain a matte coated paper of 95 g / cm ³ or less.

As the filler for the base paper for coating, it is preferable to use an amorphous silicate. In addition to the amorphous silicate, hydrated silica, white carbon, talc, kaolin,
One or more fillers such as clay, heavy calcium carbonate, light calcium carbonate, titanium oxide, and synthetic resin fillers can be used.

The pulp constituting the base paper for coating includes chemical pulp (bleached or unbleached kraft pulp of softwood, bleached or unbleached kraft pulp of hardwood), mechanical pulp (ground pulp, thermomechanical pulp, chemithermomechanical pulp) Etc.), and deinked pulp (waste paper pulp) may be used alone or mixed at an arbitrary ratio. In the present invention,
It is preferable to include mechanical pulp. Since mechanical pulp has more rigid fibers than chemical pulp, the base paper containing the mechanical pulp is less likely to collapse in the paper layer due to various pressures applied in the paper making process, and becomes bulky as a whole, so the amount of voids inside the base paper increases, The opacity increases, and at the same time the stiffness increases. Among mechanical pulps, ground pulp contributes to lower density and can be preferably used. In the case where no mechanical pulp is blended, it may not be possible to obtain sufficient opacity and rigidity even if fillers and calendering conditions are optimized.
The mechanical pulp is preferably 60% by weight or less of the papermaking pulp from the viewpoints of whiteness and coating suitability. The species of the mechanical pulp is not particularly limited, but gumwood, maple, birch and the like tend to have a low density of base paper due to coarse fibers. Pulp other than mechanical pulp is not particularly limited, and chemical pulp and waste paper pulp can be used. In particular, the use of waste paper pulp is preferable in that the mechanical pulp in the waste paper can be used as the mechanical pulp of the present invention, and that the resources are effectively used.

The method of making the base paper is not particularly limited, and a long netting machine including a top wire or the like, a round netting machine, a paperboard machine using a combination of the two, a Yankee dryer machine, or the like can be used to make an acidic paper, medium, or the like. The paper may be either a base paper made by a basic papermaking method or a base paper made by an alkaline papermaking method. Of course, a medium base paper containing mechanical pulp and a base paper containing recovered waste paper pulp can also be used. Also, using a size press, a bill blade, a gate roll coater, or a pre-metalling size press, pre-coat one or more layers of base paper pre-coated with starch, polyvinyl alcohol, etc., or a coating liquid containing pigment and adhesive. Coated base paper that has been processed can also be used.

As a method of applying the adjusted coating solution to the base paper, a blade coater, a bar coater, a roll coater, an air knife coater, a reverse roll coater, a curtain coater, a size press coater, a gate roll coater and the like are used. One or two or more layers are coated on the base paper one by one or both sides simultaneously. The coating amount is 5
40 g / m ^2, more preferably 8~16g / m ^2.

As a method for drying the wet coating layer, various methods such as a steam heating cylinder, a heated hot air dryer, a gas heater dryer, an electric heater dryer, an infrared heater dryer, and a high frequency heater dryer are used alone or in combination. Can be

The coated paper coated and dried as described above is preferably subjected to a smoothing treatment using a high-temperature soft nip calender. However, if desired coating quality can be obtained, a super calender treatment or a non-calender treatment is performed. But it is good. When a high temperature soft calender is used, not only the temperature of the rigid roll but also the nip residence time is important. From this point, in actual operation, the equivalent roll diameter is 300 mm or more, and the Shore D hardness of the elastic roll is 80 to 100, preferably 85 to 95.
When converted to a roll equivalent diameter of 500 mm, the paper passing speed is 400 to 3000 m / min. Linear pressure 10-200kg
/ Cm, pre-calender coating water content of 5 to 8%, and treatment at a calender nip number of 2 or more is preferred. The equivalent roll diameter was shown by AVLyons et al. In the following formula (19)
90 TAPPIFinishing and Converting, P5) Roll equivalent diameter
(equivalent diameter).

In the present invention, the basis weight is particularly 80 g / m
Excellent effect in matte matte coated paper of ² or less.

[0028]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but it is needless to say that the present invention is not limited to these examples.
Unless otherwise specified, parts and% in the examples indicate% by weight, respectively. In addition, the coating liquid and the obtained coated paper for offset printing were tested based on the following evaluation methods. <Evaluation method> (1) Volume distribution average particle size: Las manufactured by MALVERN Instruments
The volume distribution particle size distribution was measured using an er Diffraction particle size distribution analyzer, and the 50% point of the particle size distribution was defined as the volume distribution average particle size. (2) Blank glossiness: Measured according to JIS P8142. (3) Printing glossiness: Using a Toshiba offset rotary press (four colors), printing was performed at a printing speed of 500 rpm using a B vertical size plate, and the surface of the obtained printed matter (four-color solid printing portion) was J
It was measured based on ISP8142. (4) Ink adhesion: printing speed of 500 rpm using a Toshiba offset rotary press (4 colors) and a B vertical size plate
, And the ink adhesion of the resulting printed matter (monochrome solid printing area) was visually evaluated in four stages. ◎: Excellent, ○: Excellent, △: Slight problem,
×: There is a problem. (5) Density: Measured according to JIS P 8118. (6) Smoothness: JAPAN TAPPI No. 5 Measured based on "Testing method for smoothness and air permeability of paper and paperboard using an air micrometer type tester". (7) Opacity: Measured based on JIS P 8138. (8) Rigidity: Measured according to JIS P8143, and the evaluation was performed according to the following criteria. ◎ extremely good, ○: good,
Δ: Slightly inferior, ×: Inferior (9) Coating suitability: Evaluated according to the following criteria using as an index the story flow, scratch and fluidity of the coating liquid during blade coating. ◎ extremely good, ○: good, △: slightly poor,
×: Inferior [Example 1] Large particle size delaminated clay (Engelhar
d part Nusurf, volume distribution average particle size 5.2 μm) 70 parts,
Coarse-grained heavy calcium carbonate (FMT-FMT-
75) To 30 parts of the pigment, 0.2 parts of sodium polyacrylate as a dispersant was added as a dispersing agent, and the mixture was dispersed with a Serie mixer to prepare a pigment slurry having a solid concentration of 70%. A non-thickening styrene-butadiene latex A (glass transition temperature 2) was added to the pigment slurry thus obtained.
(0 ° C.) 13 parts and hydroxyethyl etherified starch 8 parts were added, and water was further added to obtain a coating liquid. As coating the base paper added filler fee, the coating amount per one surface quality paper in the basis weight of 50 g / m ² was added to the hydrated aluminum silicate soda becomes 5 wt% per base paper weight, 7 g on solids / The coating was performed on both sides with a blade coater at a coating speed of 1000 m / min so as to obtain m ² , and the paper was dried so that the paper moisture became 5.5%.

Next, a roll temperature of 150 ° C., 2 nips,
Calender linear pressure 80 kg / cm, paper passing speed 1000 m /
Minutes, a soft nip calendering process was performed to obtain a coated paper. [Example 2] In Example 1, the roll temperature was 70 ° C,
Nip, calender linear pressure 100 kg / cm, paper passing speed 1
A coated paper was obtained in the same manner as in Example 1 except that the soft nip calendering was performed at 000 m / min. Example 3 Example 2 was repeated except that hydrated aluminum silicate was added as an internal filler in an amount of 5% by weight based on the weight of the base paper instead of adding 5% by weight of the base paper. A coated paper was obtained in the same manner as in Example 2. Example 4 In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 μm) and coarse heavy calcium carbonate (FMT-75 manufactured by Pima Tech) were used. Instead of 30 parts, 85 parts of large particle size delaminated clay (Nusurf made by Engelhard, 5.2 μm in volume distribution average particle size) and 15 parts of coarse calcium carbonate (FMT-75 made by Fimatec) are changed. A coated paper was obtained in the same manner as in Example 1 except that the coating was performed. [Example 5] In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 µm), coarse particle heavy calcium carbonate (FMT-75 manufactured by Pima Tech) Instead of 30 parts, 35 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 μm) and 65 parts of coarse heavy calcium carbonate (FMT-75 manufactured by Fimatec) were changed. A coated paper was obtained in the same manner as in Example 1 except that the coating was performed. [Example 6] In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 µm), coarse heavy calcium carbonate (FMT-75 manufactured by Pima Tech) Instead of 30 parts, large particle size delaminated clay A (volume distribution average particle size 3.8 μm)
m) Coated paper was obtained in the same manner as in Example 1, except that 80 parts were changed to 20 parts of coarse-grained heavy calcium carbonate (FMT-75 manufactured by Fimatec). [Example 7] In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 µm), coarse heavy calcium carbonate (FMT-75 manufactured by Pima Tech) Instead of 30 parts, large particle size delaminated clay B (average particle size of volume distribution 18 μm)
m) Coated paper was obtained in the same manner as in Example 1, except that 35 parts were changed to 65 parts of coarse-grained heavy calcium carbonate (FMT-75, manufactured by FIMATECH). [Comparative Example 1] A commercially available A3 matte coated paper “NPi coated L mat” manufactured by Nippon Paper Industries having a basis weight of 64.0 g / m ² was used for comparison. Comparative Example 2 A commercially available lightly coated paper “Super Pyrene DX” having a basis weight of 64.0 g / m ² made by Nippon Paper was used for comparison. [Comparative Example 3] A commercially available fine coated mat paper “Pyrene DX” made by Nippon Paper Industries having a basis weight of 64.0 g / m ² was used for comparison. [Comparative Example 4] In Example 3, 70 parts of a large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 μm), coarse calcium carbonate (FMT-75 manufactured by Fimatec) was used. Instead of 30 parts, use delaminated clay (Rio Capim Caulim SA Capim N
Coated paper was obtained in the same manner as in Example 3, except that 80 parts of P, volume distribution average particle size of 2.5 μm) and 20 parts of coarse-grained heavy calcium carbonate (FMT-75 manufactured by Fimatec) were used. . [Comparative Example 5] In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 μm), coarse heavy calcium carbonate (FMT-75 manufactured by Pima Tech) Instead of 30 parts, 95 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, 5.2 μm in volume distribution average particle size) and 5 parts of coarse heavy calcium carbonate (FMT-75 manufactured by Fimatec) were changed. A coated paper was obtained in the same manner as in Example 1 except that the coating was performed. [Comparative Example 6] In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 μm), coarse heavy calcium carbonate (FMT-75 manufactured by Fimatec) Instead of 30 parts, 25 parts of large particle size delaminated clay (Nusurf, Engelhard Co., volume distribution average particle size 5.2 μm) and 75 parts of coarse calcium carbonate (FMT-75, Pfimatec) were changed. A coated paper was obtained in the same manner as in Example 1 except that the coating was performed. [Example 7] In Example 1, 70 parts of large particle size delaminated clay (Nusurf manufactured by Engelhard, volume distribution average particle size 5.2 µm), coarse heavy calcium carbonate (FMT-75 manufactured by Pima Tech) Instead of 30 parts, large particle size delaminated clay C (volume distribution average particle size 22 μm)
m) Coated paper was obtained in the same manner as in Example 1, except that 70 parts were changed to 30 parts of coarse-grained heavy calcium carbonate (FMT-75, manufactured by FIMATECH).

The above results are shown in Table 1.

[0031]

[Table 1]

[0032]

According to the present invention, matt matte coated paper having low density and opacity and rigidity suitable for practical use, and having high ink inking property and print gloss despite low white paper gloss. It can be obtained efficiently.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazumori Fukushima 505-1, Pulp-cho, Asahikawa-shi, Hokkaido Nippon Paper Co., Ltd. Asahikawa Mill (72) Inventor Hideki Hayasaka 505-1, Pulp-cho, Asahikawa-shi, Hokkaido Nippon Paper Stock F-term in the Asahikawa Plant (reference) 4L055 AG05 AG11 AG26 AG27 AG48 AG63 AG76 AG89 AH01 AH02 AH37 AJ04 BE08 BE20 EA08 EA11 EA12 EA13 EA16 EA20 EA32 FA11 FA12 FA15 GA19

Claims (3)

[Claims] 1. A matte coated paper for offset printing comprising a base paper on which a coating layer containing a pigment and an adhesive is provided, wherein the pigment is a delaminated pigment having a volume distribution average particle size of 3.5 to 20 μm. An offset characterized by containing 30 to 90 parts by weight of clay per 100 parts by weight of pigment, having a white paper gloss of less than 30%, a coated paper density of 0.95 g / cm ³ or less, and a smoothness of 150 seconds or more. Matte coated paper for printing. 2. The matte coated paper for offset printing according to claim 1, wherein the filler for the base paper contains amorphous silicate in an amount of 3 to 12% by weight based on the weight of the base paper. 3. A matte coated paper for offset printing, wherein the matte coated paper according to claim 1 or 2 is subjected to a soft calender treatment at a temperature of a metal roll of 100 ° C. or more.