JP2006249607A - Dull coated paper for printing use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dull coated paper low in density despite being of relatively low basis weight, and high in smoothness. <P>SOLUTION: The dull coated paper for printing use is such that pigment coating layer is formed on both sides of base paper, having been treated with a calender composed of a rough-surfaced roll and an elastic roll. In the dull coated paper, the base paper contains as filler at least one of amorphous silica and amorphous silicate at 3-12 mass% and the pigment coating layer comprises an inorganic pigment, a plastic pigment and an adhesive, wherein the inorganic pigment comprises 50-100 mass% of at least one of engineered kaolin and delaminated kaolin and ≤50 mass% of another inorganic pigment, the average particle size of the kaolin is 0.2-1.0μm (determined by sedimentation technique), and the pigment coating layer contains 2-17 pts.mass of the plastic pigment based on 100 pts.mass of the total inorganic pigment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a matte coated paper for printing, and more particularly to a dull matte coated paper having a low density despite its relatively low basis weight and yet high smoothness.

  In recent years, there has been a strong demand for enhancing visual appeal (hereinafter referred to as visualization) by frequently using photographs and designs on printed materials and adding color to them. On the other hand, there is a strong demand for weight reduction of printed matter from the viewpoints of resource saving, transportation and mail cost reduction. These demands are contradictory, and the coated paper of the grade suitable for visualization is large in both the base paper basis weight and the coating weight, and does not meet the demand for weight reduction.

  The coated paper for printing is roughly classified into high gloss coated paper and matte coated paper. High gloss coated paper includes super art paper, art paper, coated paper, and the like conventionally used for high-quality printing, and the printed finish is glossy with both high gloss and white paper gloss. On the other hand, the matte coated paper is roughly classified into a dull tone and a matte tone according to white paper gloss and printing gloss. Matte-coated paper is a coated paper that gives a flat and calm printed material with low gloss in both the white and printed areas. The dull-coated paper has low white paper gloss but high print gloss. It is a coated paper that provides an intermediate quality between glossy and matte. The dull matte coated paper is preferred as a grade suitable for visualization because it has a soothing and high-class feeling that cannot be obtained with the conventional glossy high gloss coated paper, and its demand has increased in recent years.

On the other hand, as a method for reducing the weight of coated paper, it is conceivable to reduce the base weight of the base paper and the amount of coating. However, reducing the base weight of the base paper causes a decrease in printing workability and page turnability of the printed matter. Decreasing the amount of work will be a factor in reducing print quality.
In order to improve the decrease in printing workability and page turnability, there is a method to reduce the press pressure and machine calendar pressure during base paper making to reduce the base paper density and maintain the paper stiffness (rigidity). However, if this method alone is used to reduce the density of the base paper to a satisfactory level, the smoothness of the base paper is significantly reduced, and the smoothness of the coated paper is also greatly reduced.

In addition, as a method of reducing the density of the base paper, a method of blending mechanical pulp with the pulp to be used and using amorphous silica as a filler has been proposed (see Patent Documents 1 and 2). However, blending of mechanical pulp is advantageous for lowering the density of the base paper. However, not only does the smoothness of the coated paper, which is the product, decrease due to the rigidity of the fibers, but the base paper of mechanical pulp is coated. There is a drawback that the performance of the coating liquid cannot be sufficiently drawn because the liquid tends to penetrate excessively.
In particular, matte and dull-tone coated papers generally use heavy calcium carbonate as a coating pigment in order to keep white paper gloss low, and coating layers using such pigments are smooth. When the base paper that has been reduced in density by the above-described method is finished to matte coated paper, the smoothness is further lowered.

  Further, as another method for reducing the density of the base paper, a technique (Patent Document 3) in which the base paper contains a bulking agent such as a softening agent is also known. Therefore, it is difficult for a coated paper obtained from a base paper blended with this to maintain a printing strength suitable for this.

As a means to increase the smoothness of the coated paper, it is common to perform a surface smoothing process such as super calender. However, since these processes increase the smoothness by pressurizing the paper, the paper thickness of the paper Becomes lower, and the glossiness of the blank paper becomes higher. For this reason, the nip pressure and the number of nips of the calendar are also reduced, but this method can achieve a low density, but the effect of increasing the smoothness is reduced.
Further, a coating layer using 30 to 90 parts by weight of delaminated clay having a volume distribution average particle size of 3.5 to 20 μm per 100 parts by weight of the pigment is treated with a soft calender having a metal roll temperature of 100 ° C. or more. A method for obtaining low-density matte coated paper (Patent Document 4) has also been proposed, but matte-coated paper having sufficient smoothness is difficult to obtain.

  Further, a method for obtaining a matte coated paper by passing the coated paper through a calendar made of a roughening roll and an elastic roll has been proposed. For example, the surface roughness (Rmax) is 8 to 25 μm. A method of treating with a hard roughening roll (Patent Document 5), forming a coating layer containing 10 to 30 parts by weight of synthetic resin particles with respect to 100 parts by weight of pigment, and surface roughness Rz (ten-point average roughness) ) Has been proposed (Patent Document 6) and the like, in which a blank paper glossiness is 40 or less using a calendar composed of a metal roll and an elastic roll having a thickness of 2 to 8 μm. However, the conventionally proposed methods do not provide a matte coated paper having a low density and excellent smoothness.

JP 2001-214395 A (Claim 1) JP-A-11-279988 (Claims) JP 2002-275792 A (Claim 1) JP 2002-194698 A (Claim 3) JP-A-4-119192 (Claim 1) JP-A-7-238493 (Claim 1)

  The object of the present invention is a dull having a low density and practically suitable stiffness and opacity, a low blank gloss, and a relatively high smoothness and printing gloss despite a relatively low basis weight. The object is to provide matte coated paper.

The present invention relates to a matte coated paper for printing in which a pigment coating layer is formed on both sides of a base paper and is processed with a calender consisting of a roughening roll and an elastic roll, and the base paper is amorphous silica or amorphous silicate as a filler. Is contained in an amount of 3 to 12% by weight of the base paper, the pigment coating layer is composed of an inorganic pigment, a plastic pigment and an adhesive, and the inorganic pigment contains at least engineered kaolin or delaminated kaolin. It consists of 50 to 100% by mass of one kind of kaolin and 50% by mass or less of other inorganic pigments, the average particle size of the kaolin (depending on the precipitation method) is 0.2 to 1.0 μm, It contains 2 to 17 parts by mass of plastic pigment per 100 parts by mass of all inorganic pigments.
When the inorganic pigment is composed of 50 to 85% by mass of at least one kind of engineered kaolin or delaminated kaolin and 15 to 50% by mass of other inorganic pigments, the fluidity of the coating liquid is improved. And, since the surface quality of the matte coated paper obtained is improved, it is more preferable.
The other inorganic pigments preferably have an average particle size (depending on the precipitation method) of 0.2 to 1.5 μm.
As the roughening roll, it is preferable to use a roll processed so that the maximum height roughness Rz of the roughness curve defined in JIS B 0601-2001 is 8 to 35 μm.

The matte coated paper for printing of the present invention has the properties that it has practically sufficient rigidity even at a relatively low basis weight, and has excellent smoothness and a good balance between white paper gloss and print gloss. Therefore, it has the advantage that it can be used as a matte coated paper that requires both visualization and lightening.
The matte coated paper for printing intended by the present invention has a coated paper density of 1.00 g / cm ³ or less, a blank paper glossiness (75 °) of 30 to 55%, and a printing glossiness (60 °). Matte coated paper with 40-60%, Oken type smoothness of 400 seconds or more, especially base paper basis weight of about 30-130 g / m ² and coated paper basis weight of about 45-160 g / m ² If it is, it will show a remarkable effect.

  In the present invention, a base paper containing 3 to 12% by weight of the base paper mass of at least one of amorphous silica or amorphous silicate is used as a filler, and a pigment coating layer formed on the base paper is made of an inorganic pigment, a plastic pigment, and Consists of an adhesive and, as an inorganic pigment, at least one of engineered kaolin or delaminated kaolin having a specific average particle size of 50 to 100% by mass and other inorganic pigments of 50% by mass or less are used. In addition, by containing 2 to 17 parts by mass of plastic pigment per 100 parts by mass of the total inorganic pigment, and processing with a calendar composed of a roughening roll and an elastic roll, rigidity (paper waist) that may be practically used, Delivers excellent white paper gloss, printing gloss, and smoothness, which is desirable for dull matte coated paper That.

The base paper used in the present invention is mainly composed of a pulp component and a filler. Pulp components include chemical pulp such as softwood bleached kraft pulp (NBKP) and hardwood bleached kraft pulp (LBKP), various mechanical pulps such as groundwood pulp (GP), and waste paper pulp made from various waste papers. Can be appropriately blended and used. However, in order to obtain coated paper with sufficient smoothness, the pulp component of the base paper is composed only of chemical pulp, or it is classified into old paper (for example, upper white and card) that does not contain mechanical pulp. It is desirable to use waste paper pulp made from raw paper (recycled paper classified as imitation / color).
These pulp components are beaten in accordance with a conventional method to form a pulp slurry, and at least one of amorphous silica or amorphous silicate is added to 3 to 12% by mass of the base paper mass to prepare a paper stock. Is done.
Incidentally, if the content of amorphous silica or amorphous silicate is less than 3% by mass, sufficient density reduction cannot be achieved even if the pulp blending and calendar conditions are optimized. On the other hand, if the amount exceeds 12% by mass, the number of filler particles per pulp mass becomes too large, so that the probability of inhibiting the binding between pulp fibers increases, and the strength suitable for printing workability cannot be maintained.

Examples of the amorphous silica used in the present invention include white carbon and hydrous silicic acid. Amorphous silicate is hydrous silicic acid obtained by reacting other inorganic compounds such as aluminum sulfate with sodium silicate when synthesizing hydrous silicic acid, and comprises hydrous sodium silicate and hydrous silicic acid. Examples thereof include aluminum, hydrous aluminum silicate, hydrous calcium silicate, hydrous magnesium silicate and the like. These amorphous silica and amorphous silicate may be used alone or in combination of two or more.
Among the above-mentioned amorphous silica and amorphous silicate, those having an average particle diameter (d ₅₀ ) of 3 to 35 μm corresponding to 50 cumulative mass% measured with a laser diffraction particle size distribution analyzer (SALD2000J, manufactured by Shimadzu Corporation) The average particle diameter is more preferably 5 to 25 μm. Incidentally, if a paper having an average particle diameter of less than 3 μm is used, it is difficult to obtain a sufficient paper thickness, and it may be difficult to finish a desired low-density coated paper. On the other hand, the average particle diameter exceeds 35 μm. If one is used, the smoothness and interlayer strength of the base paper may be significantly reduced.
As the amorphous silica and the amorphous silicate, those having a bulk specific gravity of 0.3 g / ml or less measured according to JIS K 5101 (a stationary method) are effective. When amorphous silica or amorphous silicate having a bulk specific gravity exceeding 0.3 g / ml is used, a base paper having a sufficient paper thickness cannot be obtained. However, since the interlayer strength of the base paper decreases as the bulk specific gravity decreases, it is necessary to take measures against the strength of the base paper. Therefore, it is preferable to use one having a bulk specific gravity of 0.05 to 0.2 g / ml. In addition, a material having a low bulk specific gravity (a material having a large specific surface area) has an effect of improving opacity and whiteness.
In the present invention, if amorphous silica or amorphous silicate satisfies both the average particle diameter and the bulk specific gravity defined here, it is preferable to reduce the density of the base paper and maintain the interlayer strength.

  In the present invention, at least one kind of amorphous silica or amorphous silicate is internally added as a filler, but other fillers such as talc, kaolin, heavy, etc. are used for the purpose of adjusting papermaking suitability and base paper strength characteristics. A small amount of fine calcium carbonate, light calcium carbonate, titanium oxide or the like may be used in combination.

To the paper stock in which filler is added to the pulp slurry, chemicals usually used in the paper making process, for example, paper strength enhancer, sizing agent, fixing agent, antifoaming agent, colorant and the like are added as necessary. Paper is made. The papermaking method is not particularly limited, and it is possible to use acidic papermaking, neutral papermaking, or alkaline papermaking using a long netting machine including a top wire, a round netting machine, a combination machine of both, a Yankee dryer machine, etc. Can be used to make paper.
The base paper of the present invention is pre-coated with starch, polyvinyl alcohol or the like using a two-roll size press coater, a gate roll coater or a pre-metering size press coater, or a coating containing a pigment and an adhesive. It is possible to pre-coat one or more working fluids.
The basis weight of the base paper can be appropriately selected from about 30 to 300 g / m ² used for general coated paper, but the effect of the present invention is remarkably exhibited because of the opacity and bulk of the base paper. It is the range of 30-130 g / m < ² > especially requested | required.

The pigment coating layer of the present invention contains an inorganic pigment (white inorganic pigment), a plastic pigment, and an adhesive as main components.
In the present invention, 50 to 100% by mass of the inorganic pigment is at least one of engineered kaolin or delaminated kaolin and an average particle size (average particle equivalent to 50 cumulative mass%) measured by a precipitation method. It is very important to use kaolin having a diameter: d ₅₀ ) of 0.2 to 1.0 μm. Incidentally, when the average particle diameter of the kaolin exceeds 1.0 μm, the glossiness of the white paper becomes low and the desired white paper glossiness cannot be obtained. When the average particle size is less than 0.2 μm, kaolin in the coating solution excessively penetrates into the base paper, so that it is difficult to form a coating layer with high smoothness and the glossiness of white paper is high. It becomes too much and cannot finish in dull tone. If the proportion of kaolin in the total inorganic pigments (total inorganic pigments) is less than 50% by mass, the glossiness and smoothness of the blank paper are lowered, and the desired glossiness and smoothness of the desired blank paper cannot be obtained.
In addition, in this invention, the average particle diameter by a sedimentation system is the value measured by Cedygraph 5100 (made by Micromeritics).

In the present invention, except that 100% by mass of the total inorganic pigment is composed of the specific engineered kaolin or delaminated kaolin, other inorganic pigments are used in combination at a ratio of 50% by mass or less of the total inorganic pigment. Become.
Examples of such other inorganic pigments include kaolin, clay, delaminated kaolin, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate, calcium sulfate, and silicic acid conventionally used as coating pigments. And inorganic pigments such as silicate, colloidal silica, and satin white. Here, kaolin refers to kaolin other than engineered kaolin and delaminated kaolin, and delaminated kaolin refers to those having an average particle diameter exceeding 1.0 μm. The other inorganic pigments described above can be used alone or in admixture of two or more as required.
Among these other inorganic pigments, those having an average particle diameter (d ₅₀ ) measured by a precipitation method of 0.2 to 1.5 μm are preferable, and those of 0.2 to 1.0 μm are more preferable.

  In the present invention, as described above, the inorganic pigment can be composed only of engineered kaolin or delaminated kaolin having a specific average particle size (according to the precipitation method), but the fluidity of the coating solution is maintained well. In order to improve the surface quality of the resulting coated paper, 50 to 85% by mass of the inorganic pigment is engineered kaolin or delaminated kaolin, and 50 to 15% by mass is another inorganic pigment. Is preferred.

Examples of the plastic pigment to be blended in the pigment coating layer include homopolymers such as styrene and methyl (meth) acrylate, copolymers such as styrene-methyl (meth) acrylate, and monomers copolymerizable therewith. Olefinic aromatic monomers such as α-methylstyrene, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid and other olefinic unsaturated carboxylic acid monomers, methyl (meth) acrylate, (meth) acrylic acid Examples thereof include resin particles made of a copolymer with an acrylic monomer such as ethyl, butyl (meth) acrylate, (meth) acrylonitrile, or an olefinic unsaturated amide monomer such as (meth) acrylamide.
These resin particles are generally spherical particles, and in the present invention, these honey-type resin particles and hollow resin particles, or even resin particles having through holes or bowl-shaped resin particles may be used. Good.
As the plastic pigment, those having an average particle diameter of about 0.5 to 1.5 μm are preferable, and among these, hollow particles having a porosity of about 30 to 60% are preferably used.
In this invention, said plastic pigment is mix | blended in the ratio of 2-17 mass parts per 100 mass parts of inorganic pigments which comprise a pigment coating layer. When the blending amount is less than 2 parts by mass, the effect of improving the smoothness after the calendering process is poor, and when it exceeds 17 parts by mass, the smoothness after the calendering process is improved, but the glossiness of the blank paper becomes excessively high, which is desirable. It cannot be finished in a dull tone. In addition, when used excessively, a new problem that the printing strength is reduced also occurs.

The adhesive constituting the pigment coating layer is not particularly limited, and an adhesive conventionally used for coated paper can be used. For example, a styrene-butadiene copolymer, Various water dispersible adhesives such as styrene / acrylic copolymer, ethylene / vinyl acetate copolymer, butadiene / methyl methacrylate copolymer, vinyl acetate / butyl acrylate copolymer, or polyvinyl alcohol, anhydrous Synthetic adhesives such as maleic acid copolymers and acrylic acid / methyl methacrylate copolymers; proteins such as casein, soy protein, and synthetic proteins; oxidized starch, positive starch, urea phosphated starch, hydroxyethyl etherified starch Etherified starch such as dextrin, starch such as dextrin; carboxymethylcellulose, hydroxymethylcellulose , Water-soluble adhesive such as cellulose derivatives such as hydroxyethyl cellulose and the like.
These adhesives can be appropriately selected and used alone or in combination of two or more.
These adhesives are used in the range of about 5 to 50 parts by mass, more preferably about 10 to 30 parts by mass, per 100 parts by mass of the pigment including the inorganic pigment and the plastic pigment.

The pigment coating layer is formed by applying and drying a pigment coating solution prepared by dispersing and mixing the above-described inorganic pigment, plastic pigment, and adhesive in an aqueous medium on a base paper.
In a pigment coating liquid, various adjuvants, such as a dispersing agent, a thickener, a water retention agent, a defoaming agent, a water-resistant agent, and a coloring agent, can be used as needed.
The prepared pigment coating solution is a blade coater, bar coater, roll coater, air knife coater, reverse roll coater, curtain coater, size press coater, gate roll coater, etc. It is applied and dried in multiple layers.
As a method for drying the pigment coating solution, various types of dryers such as a heating cylinder, a heated hot air air dryer, a gas heater dryer, an electric heater dryer, and an infrared heater dryer can be used alone or in combination.
In the present invention, when a multilayer pigment coating layer is formed on a base paper, it is possible to form the specific pigment coating layer of the present invention on both the outermost layer and the base paper side coating layer in contact with the outermost layer. However, in general, the specific pigment coating layer of the present invention is formed on the outermost layer, and another pigment coating layer is formed on the coating layer on the base paper side in contact therewith.
The coating amount of the pigment coating layer is determined according to the desired quality of the matte coated paper. For example, when the basis weight of the base paper is 70 g / m ² , the specific pigment coating layer is formed on both sides. When the coating amount is about 15 to 30 g / m ^{2 in} total (dry coating amount), sufficient coverage, high smoothness, and printed surface gloss can be obtained.

The coated paper on which the specific pigment coating layer thus obtained is formed is passed through a calendar composed of a roughening roll and an elastic roll, and finished to a matte coated paper. The roughened roll to be used is preferably a roll processed so that the maximum height roughness Rz of the roughness curve defined in JIS B 0601-2001 is 8 to 35 μm, and the maximum height roughness Rz is 8 A roll processed to have a thickness of ˜20 μm is more preferably used.
When a roughening roll having a maximum height roughness Rz of less than 8 μm is used, the effect of reducing the gloss of the white paper is poor, and the density of the coated paper is desired if the gloss of the white paper is within a desired range. Therefore, it is difficult to finish a desired dull matte coated paper. On the other hand, when a roughening roll having a maximum height roughness Rz of more than 35 μm is used, the glossiness of blank paper can be kept within a desired range, but the smoothness is lowered, and the desired matte coated paper is applied. Difficult to finish.
The number of times of paper passing through the nip composed of the roughening roll and the elastic roll is preferably processed so that each surface of the coated paper comes into contact with the roughening roll 1-3 times.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show a mass part and mass%, respectively.

The matte coated paper obtained in each example and comparative example was evaluated based on the evaluation method as described below. The evaluation results are shown in Table 1.
(Measurement of average particle size of pigment by sedimentation method)
The average particle size was measured by a sedimentation method using a Cedygraph 5100 (manufactured by Micromeritics, USA) as an average particle size (d ₅₀ ) corresponding to 50 cumulative mass%.
The pigment dispersion used for the measurement was prepared by adding a pigment slurry prepared by adding 0.05% of a dispersant (sodium polyacrylate) to a pigment with a 0.1% aqueous solution of a phosphate dispersant (nancarin). The pigment solid content concentration was obtained by diluting to about 1%.

(Blank gloss)
The resulting matte coated paper was conditioned in an environment of 23 ° C ± 1 ° C and (50 ± 2)% RH, and then the gloss meter (GM-26D, Murakami Color Research Laboratory) 75 ° glossiness was measured using ISO 8254-Part 1).
(Smoothness)
The resulting matte coated paper is conditioned at 23 ° C ± 1 ° C and (50 ± 2)% RH, and under the same conditions, the JAPAN TAPPI paper / pulp test method No.5-2 “Air It was measured based on the “smoothness / air permeability test method of paper and paperboard using a micrometer type tester”.

(density)
Measured based on JIS P 8118-1998.
(Print gloss)
The resulting matte coated paper was conditioned in an environment of 23 ° C ± 1 ° C and (50 ± 2)% RH, and in that environment, the printing ink (Varius G ink N Type, manufactured by Dainippon Ink Co., Ltd.) was used for 0.3 cc, and after standing for 1 day, 60 ° gloss was measured using a gloss meter (GM-26D type, manufactured by Murakami Color Research Laboratory).
(Surface strength)
The resulting matte coated paper was conditioned in an environment of 23 ° C. ± 1 ° C. and (50 ± 2)% RH, and then in that environment, the printing ink (SD50 for paper test) was measured with an RI printing tester. (Red, manufactured by Toyo Ink Co., Ltd.) was used for printing, and the degree of picking on the printed surface was visually evaluated.
A: Picking does not occur at all and the surface strength is extremely good.
○: Picking is slightly occurring, but it is a good level as coated paper.
(Triangle | delta): Picking has generate | occur | produced and surface strength is inferior.
X: A lot of picking occurs and the surface strength is considerably inferior.

Example 1
[Preparation of base paper]
A pulp slurry comprising 75 parts of LBKP (freeness 450 ml / csf) and 25 parts of NBKP (freeness 450 ml / csf) was used to make amorphous silicate (average particle size: 9.0 μm, bulk specific gravity: 0.19 g / ml) as a filler. It is added so as to be 10% by mass of the base paper mass, and 0.01 parts of AKD sizing agent (trade name: Size Pine K-902, manufactured by Arakawa Chemical Co., Ltd.) as an internal sizing agent with respect to 100 parts of pulp. Conversion) and 0.5 parts of aluminum sulfate (in terms of solid content) were added to prepare a paper stock. Papermaking is performed using this stock, and surface sizing press (oxidized starch coating amount on both sides: 2.5 g / m ² ) using oxidized starch (Ace A, manufactured by Oji Cornstarch Co., Ltd.) is performed. A coated base paper of m ² fine paper was obtained.
In addition, the average particle diameter and bulk specific gravity of the filler internally added to the base paper are obtained by taking a value corresponding to 50 cumulative mass% measured by a laser diffraction particle size distribution measuring apparatus (SALD2000J, manufactured by Shimadzu Corporation) as an average particle diameter. Specific gravity is a value measured according to JIS K 5101 (stationary method).

[Preparation of pigment coating solution]
The average particle diameter d ₅₀ of 0.5μm engineered kaolin as measured by sedimentation method (trade name: Contrast 300, manufactured by Engelhard) 55 parts, the mean particle size d ₅₀ of 0.8μm fine heavy measured by sedimentation method To a pigment consisting of 45 parts of calcium carbonate (trade name: Hydrocurve 90, manufactured by Bihoku Flour & Chemical Co., Ltd.), 0.1 part of poly (sodium acrylate) as a dispersant is added as a dispersant and dispersed with a mixer. A pigment slurry having a concentration of 70% was prepared. To this pigment slurry, 12 parts of hollow plastic pigment (trade name: Ropeke HP91, average particle size: 1 μm, porosity: 55%, manufactured by Rohm and Haas) per 100 parts of inorganic pigment, styrene-butadiene copolymer latex (product) Name: Sumatex PA2327, manufactured by Nippon A & L Co., Ltd. 10 parts (solid content), oxidized starch (trade name: Ace A, supra) 2 parts (solid content) and other auxiliaries are added, and finally the solid content concentration A 58% pigment coating solution was prepared.

[Manufacture of coated paper]
The above-mentioned base paper is coated on both sides with a blade coater with a coating speed of 800 m / min so that the dry coating amount per side of the above pigment coating solution is 10 g / m ^2. % Was dried to produce a coated paper.
[Manufacture of matte coated paper]
Next, the coated paper obtained above is composed of a roughened roll and an elastic roll whose roll surface is processed so that the maximum height roughness Rz defined by JIS B 0601-2001 is 15 to 20 μm. A calendered paper was produced by calendering with a calender under the condition of 4 nips.

Example 2
In the preparation of the base paper of Example 1, amorphous silica (average particle diameter: 19.9 μm, bulk specific gravity: 0.10 g / ml) was used as a filler to be added to the pulp. A coated base paper was obtained in the same manner as in Example 1 except that it was added as described above.
In the preparation of the pigment coating solution of Example 1, 85 parts of delaminated kaolin (trade name: Contour 1500, manufactured by Imeris) with an average particle diameter d ₅₀ measured by a precipitation method of 0.46 μm, and precipitation Using 15 parts of fine heavy calcium carbonate (trade name: Hydrocurve 90, manufactured by Bihoku Powder Chemical Co., Ltd.) with an average particle diameter d ₅₀ measured by the method of 0.8 μm, hollow plastic pigment (product) per 100 parts of inorganic pigment A pigment coating solution was prepared in the same manner as in Example 1 except that 3 parts (name: Ropeke HP91, average particle size: 1 μm, porosity: 55%, manufactured by Rohm and Haas) were blended.
A matte coated paper was obtained in the same manner as in Example 1 except that the above pigment coating solution was applied to the base paper obtained above and dried.

Example 3
In preparation of the pigment coating solution of Example 1, 85 parts of engineered kaolin (trade name: Contrast 300, manufactured by Engelhard) and fine heavy calcium carbonate (trade name: Hydrocurve 90, manufactured by Bihoku Powdered Industries Co., Ltd.) Example 1 except that 15 parts were used and 3 parts of hollow plastic pigment (trade name: Ropeke HP91, average particle size: 1 μm, porosity: 55%, manufactured by Rohm and Haas) per 100 parts of inorganic pigment were blended In the same manner, a pigment coating solution was prepared.
A matte coated paper was obtained in the same manner as in Example 1 except that the pigment coating solution obtained above was used.

Example 4
In the preparation of the pigment coating solution of Example 1, 75 parts of delaminated kaolin (trade name: Capim DG, manufactured by RCC) having an average particle diameter d ₅₀ measured by a precipitation method of 0.61 μm and a measurement by the precipitation method The hollow plastic pigment (AE-851) per 100 parts of inorganic pigment is used with 25 parts of fine heavy calcium carbonate (trade name: Hydrocurve 90, manufactured by Bihoku Flour & Chemical Co., Ltd.) having an average particle diameter d ₅₀ of 0.8 μm. A pigment coating solution was prepared in the same manner as in Example 1 except that 5 parts of (average particle size: 1 μm, porosity: 55%, manufactured by JSR) were blended.
A matte coated paper was obtained in the same manner as in Example 1 except that the pigment coating solution obtained above was used.

Comparative Example 1
In the preparation of the base paper of Example 1, amorphous silicate (average particle size: 9.0 μm, bulk specific gravity: 0.19 g / ml) was used as a filler to be added to the pulp so as to be 1% by mass of the paper made. The same procedure as in Example 1 was conducted, except that light calcium carbonate (average particle size: 6.1 μm, bulk specific gravity: 0.23 g / ml) was further added so as to be 7% by mass of the base paper mass. Coating base paper was obtained.
A matte coated paper was obtained in the same manner as in Example 1 except that the coated base paper obtained above was used.

Comparative Example 2
In the preparation of the base paper of Example 1, amorphous silicate (average particle size: 6.0 μm, bulk specific gravity: 0.19 g / ml) was used as a filler to be added to the pulp so as to be 15% by mass of the base paper mass. A coated base paper was obtained in the same manner as Example 1 except for the addition.
A matte coated paper was obtained in the same manner as in Example 1 except that the coated base paper obtained above was used.

Comparative Example 3
In the preparation of the base paper of Example 1, light calcium carbonate (average particle size: 6.1 μm, bulk specific gravity: 0.23 g / ml) was used instead of amorphous silicate as a filler to be added to the pulp. A coated base paper was obtained in the same manner as in Example 1 except that it was added so as to have a mass%.
A matte coated paper was obtained in the same manner as in Example 1 except that the coated base paper obtained above was used.
A coated paper was obtained in the same manner as in Example 1.

Comparative Example 4
In the preparation of the pigment coating solution of Example 1, 55 parts of engineered kaolin (trade name: Contrast 300, manufactured by Engelhard) having an average particle diameter d ₅₀ of 0.5 μm measured by the precipitation method and measured by the precipitation method. Instead of 45 parts of fine heavy calcium carbonate having a mean particle diameter d ₅₀ of 0.8 μm (trade name: Hydrocurve 90, manufactured by Bihoku Powder Chemical Co., Ltd.), the average particle diameter d ₅₀ measured by the sedimentation method is 0.00. 40 parts of 21 μm high white fine kaolin (trade name: Hydra Gloss 90, manufactured by Huba Co., Ltd.) and fine heavy calcium carbonate (trade name: Hydrocurve 90, whose average particle diameter d ₅₀ measured by the sedimentation method is 0.8 μm) A pigment coating solution was prepared in the same manner as in Example 1 except that 60 parts of (Bihoku Powder Chemical Co., Ltd.) were used.
A matte coated paper was obtained in the same manner as in Example 1 except that the pigment coating solution obtained above was used.

Comparative Example 5
In the preparation of the pigment coating solution of Example 1, 55 parts of engineered kaolin (trade name: Contrast 300, manufactured by Engelhard) having an average particle diameter d ₅₀ of 0.5 μm measured by the precipitation method and measured by the precipitation method. Instead of 45 parts of fine heavy calcium carbonate having a mean particle diameter d ₅₀ of 0.8 μm (trade name: Hydrocurve 90, manufactured by Bihoku Flour Industry Co., Ltd.), the average particle diameter d ₅₀ measured by the sedimentation method is 2. 75 μm of 1 μm large particle size delaminated kaolin (trade name: New Surf, manufactured by Engelhard) and fine heavy calcium carbonate (trade name: Hydro) having an average particle diameter d ₅₀ measured by the sedimentation method of 0.8 μm A pigment coating solution was prepared in the same manner as in Example 1 except that 25 parts of Curve 90 (manufactured by Bihoku Powder Chemical Co., Ltd.) were used.
A matte coated paper was obtained in the same manner as in Example 1 except that the pigment coating solution obtained above was used. ,

Comparative Example 6
A pigment coating solution was prepared in the same manner as in Example 1 except that in the preparation of the pigment coating solution of Example 1, the amount of the hollow plastic pigment was 1 part per 100 parts of the inorganic pigment.
A matte coated paper was obtained in the same manner as in Example 1 except that the pigment coating solution obtained above was used.

Comparative Example 7
In the preparation of the pigment coating solution of Example 1, a pigment coating solution was prepared in the same manner as in Example 1, except that the amount of the hollow plastic pigment was 20 parts per 100 parts of the inorganic pigment.
A matte coated paper was obtained in the same manner as in Example 1 except that the pigment coating solution obtained above was used.

Comparative Example 8
In the preparation of the base paper of Example 1, a coated base paper was prepared in the same manner as in Example 1 except that instead of a pulp blend consisting of 75 parts LBKP and 25 parts NBKP, a pulp blend consisting of 55 parts LBKP, 25 parts NBKP and 20 parts mechanical pulp was used. Got.
A matte coated paper was obtained in the same manner as in Example 1 except that the base paper obtained above was used.

Comparative Example 9
In the production of matte coated paper of Example 1, a coated paper was obtained in the same manner as in Example 1 except that the calender used was a calender consisting of a plain roll and an elastic roll. It was.

  At least one of amorphous silica or amorphous silicate used as a filler in a matte coated paper for printing, which is formed with a pigment coating layer on both sides of a base paper and processed with a calender consisting of a roughening roll and an elastic roll. 3-12 mass% of the base paper mass, the pigment coating layer is composed of an inorganic pigment, a plastic pigment and an adhesive, and the inorganic pigment is at least one kaolin of engineered kaolin or delaminated kaolin It consists of 50 to 100% by mass and other inorganic pigments of 50% by mass or less. The average particle size of the kaolin (depending on the precipitation method) is 0.2 to 1.0 μm, and the pigment coating layer is 100% of the total inorganic pigment. By containing 2 to 17 parts by mass of plastic pigment per part by mass, it has a low density and high smoothness even though it has a relatively low basis weight. Since matte coated paper can be obtained efficiently, it can also be applied as matte coated paper that satisfies the demands of both weight reduction and visualization.

Claims (4)

  At least one of amorphous silica or amorphous silicate used as a filler in a matte coated paper for printing which is formed with a pigment coating layer on both sides of a base paper and processed with a calender consisting of a roughening roll and an elastic roll. 3-12 mass% of the base paper mass, the pigment coating layer is composed of an inorganic pigment, a plastic pigment and an adhesive, and the inorganic pigment is at least one kaolin of engineered kaolin or delaminated kaolin It consists of 50 to 100% by mass and other inorganic pigments of 50% by mass or less. The average particle size of the kaolin (depending on the precipitation method) is 0.2 to 1.0 μm, and the pigment coating layer is 100% of the total inorganic pigment. Matt printed paper for printing, characterized in that it contains 2 to 17 parts by weight of plastic pigment per part by weight.   The matte coating for printing according to claim 1, wherein the inorganic pigment comprises 50 to 85% by mass of at least one kind of engineered kaolin or delaminated kaolin and 15 to 50% by mass of the other inorganic pigment. Paper.   The matte coated paper for printing according to claim 1 or 2, wherein the other inorganic pigment has an average particle size (by a sedimentation method) of 0.2 to 1.5 µm.   The surface roughening roll is a roll processed so that the maximum height roughness Rz of the roughness curve defined in JIS B 0601-2001 is 8 to 35 µm. Matte coated paper for printing as described.