KR101098261B1 - Coated paper for printing - Google Patents

Abstract

Providing printing escaping paper with a large volume, high white paper gloss, and excellent printability such as printing gloss and printing smoothness.

In the printing cover paper provided with two layers of coating layers containing a pigment component and an adhesive component as a main component on at least one side of a relatively bulky paper, the average particle diameter measured by the light scattering method on the pigment component of the undercoat layer (d50). ₁ ) and the specific delaminated kaolin defined by the average particle diameter (d50 ₂ ) measured by the sedimentation method.

White paper gloss, printing, smoothness, printability, printing paper, delaminated kaolin.

Description

Printable Evacuation Paper {COATED PAPER FOR PRINTING}

The present invention relates to a bulky printing repellent paper with improved smoothness.

In general, printing paper is produced by applying a coating liquid containing pigment and adhesive as a main component on at least one side of a base paper and drying it. Printing vellum is classified into cast coated paper, art paper, coated paper, uncoated paper, and the like by the coating amount of the coating liquid and the method of finishing the coating paper. These papers are multicolored or monochromatic printed on them, and are widely used as commercial printed matters such as advertisements, pamphlets, posters, or publications such as books and magazines.

In recent years, the visualization and colorization of printed matters are progressing, and the demand for the high quality of the printed paper is increasing. Specifically, the improvement of the glossiness, smoothness and whiteness of the printing dope itself is required.

As one of the methods of improving the smoothness of the printing paper, it is proposed to mix the dilaminated kaolin in the coating layer (see Patent Documents 1 to 3). Since delaminated kaolin has a flat or flat particle shape, when providing smoothness to the coating layer, it is preferable to use this as a pigment component of the coating layer.

Another method of improving the smoothness of printing dope is to use satin white as the pigment component of the coat layer (see Patent Documents 4 to 7). Satin white is a white pigment of acicular crystal produced by reaction of calcium hydroxide and aluminum sulfate, for example, and the official name is calcium trisulfo aluminate. Satin white is an inorganic complex compound represented by following General formula (1), It is known that the surface of the coating layer which mix | blended this shows the outstanding smoothness.

3CaOAl ₂ O ₃ 3CaSO ₄ 31-32H ₂ O (1)

In the conventional printing paper, there is also provided one coating layer (hereinafter referred to as a coating layer) below the coating layer (hereinafter referred to as an overcoat layer) serving as an ink repair layer.

For example, as one of the pigment components of the undercoat layer, there is known a printing paper (see Patent Documents 8 to 10) containing kaolin and a printing paper (see Patent Document 11) containing a satin white. However, the printing vellum using the delaminated kaolin as the pigment component of the undercoat layer is not known until now.

When the undercoat layer is provided, it is common that the surface smoothness of the layer affects the smoothness of the overcoat layer (ink repair layer) provided on the undercoat layer, and the smoothness of the overcoat layer responsible for ink repair. Determines the glossiness of the layer. Therefore, in order to obtain printing vellum having excellent gloss, smoothness and whiteness, not only the overcoat layer (= ink repair layer) but also the constitution of the undercoat layer should be devised.

Moreover, in addition to excellent gloss, smoothness and whiteness required for printing vellum, in recent years there has been a tendency to draw attention to the touch (paper quality) and the apparent specific volume of each sheet of vellum. In particular, it is a recent trend that larger volumes of vellum for publications are preferred.

To increase the volume of the printing paper, a method of increasing the volume of the paper itself by adding a bulking agent (see Patent Documents 12 to 13), or a method of treating the coating layer coated on the paper by thermal soft calendar or the like (patent) Documents 14 to 16) or a method of using a hollow plastic pigment (see Patent documents 17 to 18) or the like as a pigment to be blended into the coating layer has been conventionally proposed.

That is, the conventional proposal regarding volume reinforcement employs a relatively large base paper as a base paper for printing printing paper, and calenders the coated paper obtained by applying the coating liquid onto the paper, to the base paper or the coating layer. The application is to keep the pressure as small as possible. However, the reduction of the pressing force at the time of calendering treatment has a flaw that becomes smaller as compared with the case where the smoothing action of the coating layer by calendering treatment is not reduced.

Therefore, in more detail, in order to obtain the smooth coating of the coating layer, which is excellent in the smoothness, more specifically, the coating layer before the calendering treatment under mild conditions has a certain degree of smoothness. It is important to be.

Even in the mild calendering process, one of the prior arts for obtaining vellum having excellent smoothness is, as described above, a pigment of the overcoat layer, which is believed to contribute to the smoothing of the overcoat layer. For example, satin white or delaminated kaolin) is used. The other is a method of increasing the thickness of the coating layer and camping the unevenness of the surface of the coating layer with the coating layer.

However, since a predetermined basis weight is defined for the bleed paper, not only can the thickness of the overcoat layer be unnecessarily increased, but the increase of the thickness of the overcoat layer inevitably increases the density of the shed paper. Therefore, in the case of employing the former method, it is difficult to obtain bulky dope.

Normal printing vellum that does not emphasize `` volume enhancement '' generally has a bulk density in the range of 1.15 to 1.25 g / cm 3. Therefore, the term "volume printing vellum" as used herein refers to vellum having a bulk density of 1.10 g / cm 3 or less and typically 1.05 g / cm 3 or less. In addition, the bulk density was measured in accordance with the provisions of ISO 534: 1988.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2002-27443

[Patent Document 2] Japanese Patent Application Laid-Open No. 2002-220795

[Patent Document 3] Japanese Unexamined Patent Publication No. 11-302998

[Patent Document 4] Japanese Patent Application Laid-Open No. 11-247097

[Patent Document 5] Japanese Patent Application Laid-Open No. 09-256295

[Patent Document 6] Japanese Patent Application Laid-Open No. 09-67794

[Patent Document 7] Japanese Patent Application Laid-Open No. 02-14098

[Patent Document 8] Japanese Patent Application Laid-Open No. 2003-268695

[Patent Document 9] Japanese Unexamined Patent Publication No. 2002-69894

[Patent Document 10] Japanese Patent Application Laid-Open No. 08-120569

[Patent Document 11] Japanese Patent Application Laid-Open No. 07-238495

[Patent Document 12] Japanese Patent Application Laid-Open No. 2002-155494

[Patent Document 13] Japanese Unexamined Patent Publication No. 2003-171893

[Patent Document 14] Japanese Patent No. 3249212

[Patent Document 15] Japanese Patent Application Laid-Open No. 09-228298

[Patent Document 16] Japanese Unexamined Patent Publication No. 06-294100

[Patent Document 17] Japanese Patent Application Laid-Open No. 2002-220795

[Patent Document 18] Japanese Patent Application Laid-Open No. 09-119090

The present invention is a printing paper paper provided with at least one surface of a base paper with two layers of a coating layer composed mainly of a white pigment and an adhesive, and has a bulky printing paper with a bulk density of 1.05 g / cm 3 or less while having excellent smoothness. To provide.

Therefore, the printing dope for printing according to the present invention has a bulk density of 1.05 g / cm 3 or less, provided with at least one surface of a paper having a bulk density of 0.75 g / cm 3 or less and having two layers of coating layers composed mainly of a white pigment component and an adhesive component. In the coated paper, all of the pigment components contained in the undercoat layer in contact with the overcoat layer are composed of delaminated kaolin satisfying the following conditions, or at least 50 mass% of the pigment components satisfy the following conditions. It is a dilaminated kaolin, and the remainder is another white pigment, The average particle diameter measured by the sedimentation method of this white pigment exists in the range of 0.1-1.3 micrometer, and the quantity of the adhesive component of an undercoat layer is an undercoat layer It is the range of 10-20 mass parts per 100 mass parts of pigment components contained in

Delaminated kaolin:

The average particle diameter (d50 ₁ ) measured by the light scattering method is in the range of 2.0-5.0 micrometers, and the average particle diameter (d50 ₂ ) measured by the sedimentation system exists in the range of 0.30-0.55 micrometer, Furthermore, the average particle Delaminated kaolin having a ratio (d50 ₁ / d50 ₂ ) of a diameter (d50 ₁ ) to an average particle diameter (d50 ₂ ) of 4 or more.

Satin white is mentioned as white pigments other than the dilaminated kaolin contained in an undercoat layer, It is preferable that the content is the range of 1-30 mass% of the pigment component contained in a undercoat layer.

As the adhesive component of the undercoat layer, it is preferable to use a dispersible adhesive having a particle diameter of the dispersed particles in the range of 50 to 120 nm, particularly in the range of 50 to 100 nm. It is preferable to make the quantity 7 mass parts or less per 100 mass parts of pigment components.

In the present invention, the average particle diameter referred to with respect to the pigment component means an average particle diameter measured by the sedimentation method. And d50 ₁ means the average particle diameter of the delaminated kaolin measured by the light scattering system, and d50 ₂ means the average particle diameter of the delaminated kaolin measured by the sedimentation system.

In the printing coating paper according to the present invention, the pigment component of the overcoat layer is composed of a white pigment having an average particle diameter in the range of 0.1 to 1.3 mu m. It is preferable that the quantity of the adhesive component of an overcoat layer is the range of 10-20 mass parts per 100 mass parts of pigment components of an overcoat layer.

It is preferable that the 1-30 mass% of the pigment component of an overcoat layer is satin white.

It is preferable that the 1-30 mass% of the pigment component of an overcoat layer is a plastic pigment.

As the adhesive component of the overcoat layer, it is preferable to use a dispersible adhesive having a particle diameter of the dispersed particles in the range of 50 to 120 nm, particularly in the range of 50 to 100 nm, and when using a water-soluble adhesive together, It is preferable to make an amount 4 mass parts or less per 100 mass parts of pigment components.

(The best mode for carrying out the invention)

The base paper used in the present invention is the only condition that the bulk density (density) is 0.75 g / cm 3 or less, and as long as this condition is satisfied, any kind of raw material pulp and papermaking conditions at the time of producing the base paper itself are not at all. Does not matter. In addition, it does not matter whether the paper is size-pressed or not.

The coated paper of the present invention can be produced by sequentially forming an undercoat layer and an overcoat layer on at least one side of a base paper having a bulk density of 0.75 g / cm 3 or less. The undercoating layer and the overcoat layer are mainly composed of a pigment component and an adhesive component which are all composed of a white pigment.

In the printing coating paper of the present invention, the pigment component constituting the undercoat layer is in the range of 0.1 to 1.3 mu m, preferably in the range of 0.3 to 1.0 mu m, even if it is any kind. When the average particle diameter of the pigment component constituting the undercoat layer is more than 1.3 μm, it is difficult to impart excellent smoothness to the undercoat layer itself, and when it is less than 0.1 μm, it is preferable to give smoothness, but undercoat It is disadvantageous in economics because it requires a relatively large amount of adhesive to form the layer.

As for the pigment component of an undercoat layer, 50 mass% or more, Preferably 70-95 mass% occupies for a specific dilaminated kaolin. Here, the specific delaminated kaolin refers to the delaminated kaolin specified by d50 ₁ and d50 ₂ as described. Incorporation of specific delaminated kaolin in the undercoat layer is extremely suitable for imparting excellent smoothness to the undercoat layer itself. When content of specific delaminated kaolin is less than 50 mass% of the pigment component of a coating layer, it is difficult to provide the outstanding smoothness to the coating layer itself.

Although the shape characteristics of flat particles such as delaminated kaolin can be defined by the ratio (aspect ratio) of the long diameter d and the thickness t, in the present invention, the shape characteristics of the delaminated kaolin, The average particle diameter d50 ₁ by the light scattering method and the average particle diameter d50 ₂ by the sedimentation method are defined.

In the measurement of the average particle diameter d50 ₁ by the light scattering method, all the individual particles are regarded as spherical particles, and their diameters are measured. On the other hand, in the measurement of the average particle diameter (d50 ₂ ) by the sedimentation method, since the particle shape affects the sedimentation property, particles having a flat or flat shape and slow sedimentation are visually measured as small particles. . For this reason, it is thought that the larger the aspect ratio is, the larger the ratio d50 ₁ / d50 ₂ of the average particle diameter d50 ₁ by the light scattering method and the average particle diameter d50 ₂ by the sedimentation method.

In the present invention, a laser diffraction particle size distribution analyzer SALD-2000 (manufactured by Shimadzu Corporation) is used for the measurement of the average particle diameter by the light scattering method, and a cedi graph is used for the measurement of the average particle diameter by the sedimentation method. 5100 (manufactured by Micromeritics, Inc.) was used.

In the present invention, the d50 ₁ of the delaminated kaolin contained in the undercoat layer is in the range of 2.0 to 5.0 μm, preferably in the range of 2.2 to 4.7 μm, and d50 ₂ is preferably 0.30 to 0.55 μm. Is in the range of 0.35 to 0.50 µm. And, d50 ₁ and non, ₁ d50 / d50 d50 of ₂ is _2, 4 or more, and preferably a value greater than 5.

Incidentally, when the d50 ₁ and d50 ₂ of the delaminated kaolin contained in the undercoat layer are less than 2.0 µm and less than 0.30 µm, respectively, the delaminated kaolin in the coating liquid penetrates excessively into the base paper. Therefore, it becomes difficult to form a coating layer with high smoothness. Further, even in the case exceeds a d50 d50 ₁ and _2, respectively, and 5.0㎛ 0.55㎛, it is difficult to form a high smoothness escape layer. And, d50 from which it becomes ₁ / d50 ₂ in the case of less than 4 degrees, and over-penetrate the circle doing because the flat property (flatness) of the pigment is low, the smoothness is difficult to form a high escape layer, of the present invention It is difficult to obtain print vellum.

The undercoating layer of the printing paper for printing according to the present invention can comprise all of its pigment components with a specific delaminated kaolin. In addition, the pigment component of the undercoat layer may be composed of a specific delaminated kaolin and another white pigment. It is preferable that the other white pigment in this case is satin white which has a predetermined average particle diameter, and the content is 1-30 mass% of a pigment component, It is preferable that it is especially the range of 3-20 mass%. Inclusion of satin white in the undercoat layer is suitable for imparting excellent smoothness to the undercoat layer itself. When the amount of satin white is less than 1% by mass of the pigment component of the coating layer, the effect of imparting excellent smoothness to the coating layer itself is small. On the other hand, when the amount of satin white exceeds 30% by mass of the pigment component of the undercoat layer, the smoothness of the undercoat layer itself is improved, but since a relatively large amount of adhesive is required for the formation of the undercoat layer, it is disadvantageous in terms of economy. .

Examples of white pigments other than those mentioned above which can be used as pigment components of the undercoat layer include calcium carbonate, kaolin, calcined kaolin, engineered kaolin, talc, calcium sulfate, barium sulfate, aluminum hydroxide, titanium dioxide, zinc oxide, alumina Inorganic pigments such as magnesium carbonate, magnesium oxide, silica, aluminosilicate silicate, calcium silicate bentonite, zeolite, sericite, smectite, or solid, hollow or porous plastic pigtails And the like can be exemplified. One or two or more of these compounds can be used in combination with dilaminated kaolin as long as they have a predetermined average particle diameter.

Dispersible adhesives are usually used for the adhesive component of the undercoat layer. As a dispersion type adhesive agent, conjugated diene polymer latex, such as a styrene butadiene copolymer and a methyl methacrylate butadiene copolymer, an acryl-type polymer latex, vinyl polymer latex, such as ethylene-vinyl acetate copolymer, etc. can be illustrated. Even if any dispersed adhesive is used, the particle diameter of the dispersed adhesive particles is preferably in the range of 50 to 120 nm, particularly 50 to 100 nm. Said dispersion type adhesive agent can also use 2 or more types together.

In the adhesive component of the undercoat layer, a small amount of water-soluble adhesive can be used in combination with the above-described dispersion type adhesive. As a water-soluble adhesive, various starches, such as an oxidized starch, esterified starch, and a cold water soluble starch, proteins, such as casein, a soy protein, and a synthetic protein, cellulose derivatives, such as carboxymethyl cellulose and methyl cellulose, polyvinyl alcohol, and its modified products Etc. can be illustrated.

The amount of the adhesive component contained in the undercoat layer is selected in the range of 10 to 20 parts by mass, in particular 10 to 18 parts by mass, per 100 parts by mass of the pigment component contained in the undercoat, regardless of whether or not a water-soluble adhesive is used in combination. . When the content of the adhesive component is less than 10 parts by mass, the binding power is insufficient, and when the content of the adhesive component is more than 20 parts by mass, the smoothness of the coating layer may be impaired.

When using a water-soluble adhesive together, it is preferable to make the content into 7 mass parts or less, especially 4 mass parts or less per 100 mass parts of pigment components. It is not preferable to exceed 7 parts by mass because the smoothness of the undercoat layer is inferior. The use of a small amount of water-soluble adhesives in combination with a dispersion type adhesive is effective for thickening and repairing a coating mixture forming a coating layer.

The undercoat layer of the printing vellum according to the present invention is a pigment component consisting of only delaminated kaolin that satisfies specific conditions, or other white pigment 50 having 50 mass% or more of the delaminated kaolin and a specific average particle diameter. A first coating liquid containing a pigment component composed of less than mass% and an adhesive agent of 10 to 20 parts by mass per 100 parts by mass of the pigment component is formed by coating on one or both sides of the base paper and drying. Although roll coating, air knife coating, bar coating, blade coating, etc. can be employ | adopted as coating, adoption of blade coating is preferable. The coating amount of the first coating liquid is selected in the range of 10 to 20 g / m 2 per single side of the base paper in total with the coating amount of the second coating liquid used for forming the coating layer to be described later.

It is preferable to adjust the PPS smoothness of the undercoat layer obtained from the 1st coating liquid in the range of 2.0-3.5 micrometers, especially in the range of 2.6-3.2 micrometers. The PPS smoothness of the undercoat layer obtained by blade coating the first coating liquid of the above composition on a base paper is usually in the range specified above.

For the sake of clarity, in the case of forming the coating layer with the second coating liquid, which will be described later in detail, when the blade coating is adopted, if the PPS smoothness of the coating layer is less than 2.0 µm, streaking the coating layer Streak or scratch may occur. However, when the PPS smoothness of the undercoat layer is 2.6 µm or more, generation of streaks or scratches can be completely prevented.

The overcoating layer of the printing coating paper according to the present invention has a white pigment component having an average particle diameter in the range of 0.1 to 1.3 μm, preferably 0.3 to 1.0 μm, and 10 to 20 mass per 100 parts by mass of the white pigment component. A second coating mixture containing a negative adhesive is formed by coating and drying the surface of the undercoat layer already formed on the base paper. Although roll coating, air knife coating, bar coating, blade coating, etc. can be employ | adopted as coating, adoption of blade coating is preferable. The coating amount of the second coating liquid is selected in the range of 10 to 20 g / m 2 per one side of the base paper as a total of the coating amount of the first coating liquid to be used for forming the undercoat coating layer.

The reason for defining the average particle diameter of the white pigment contained in the overcoat layer as described above is substantially the same as that for the undercoat layer. It is preferable that the pigment component of an overcoat layer contains 1-30 mass%, especially 3-20 mass%, and contains the satin white and / or plastic pigment which have a predetermined average particle diameter. The reason is substantially the same as in the case of the above-described undercoat layer.

As a white pigment other than satin white and a plastic pigment which can be used for an overcoat layer, for example, calcium carbonate, calcined kaolin, engineered kaolin, dilaminated kaolin, talc, calcium sulfate, barium sulfate, aluminum hydroxide, 2 Inorganic pigments such as titanium oxide, zinc oxide, alumina, magnesium carbonate, magnesium oxide, silica, aluminosilicate silicate, calcium silicate bentonite, zeolite, sericite, smectite and the like. One type or two types or more of these white pigments can be used by this invention as long as the average particle diameter is a predetermined range.

As an adhesive component of an overcoat layer, a dispersion type adhesive agent is normally used similarly to the case of the undercoat layer mentioned above. Examples of the dispersible adhesives include conjugated diene polymer latexes such as styrene-butadiene copolymer and methyl methacrylate butadiene copolymer, vinyl polymer latexes such as acrylic polymer latex and ethylene-vinyl acetate copolymer, and the like. 1 type, or 2 or more types of can be used as an adhesive component of an outermost coating layer.

It is preferable that the said dispersion type adhesive used for formation of an overcoat layer contains 10-35 mass% of acrylonitrile, especially 20-30 mass% as a monomer at the time of superposition | polymerization. When the acrylonitrile content of the dispersible adhesive is less than 10% by mass, the ink solvent absorbency of the formed overcoat layer cannot be satisfactorily satisfied, and there is a possibility that print gloss may be damaged. On the other hand, when the acrylonitrile content of the dispersible adhesive exceeds 35% by mass, the emulsion polymerization becomes difficult, and binding power that can satisfy this cannot be expected.

Even when the adhesive component of the overcoat layer uses any dispersed adhesive, the particle size of the dispersed adhesive particles is preferably in the range of 50 to 120 nm, particularly 50 to 90 nm.

A small amount of water-soluble adhesives can be used together with the above-described dispersible adhesives. As a water-soluble adhesive, various starches, such as an oxidized starch, esterified starch, and a cold water soluble starch, proteins, such as casein, a soy protein, and a synthetic protein, cellulose derivatives, such as carboxymethylcellulose and methylcellulose, polyvinyl alcohol, and the like Modified products etc. can be illustrated.

The amount of the adhesive component contained in the overcoat layer is selected from 10 to 20 parts by mass, in particular from 10 to 18 parts by mass, per 100 parts by mass of the pigment component contained in the overcoat layer, regardless of whether or not a water-soluble adhesive is used in combination. . When the content of the adhesive component is less than 10 parts by mass, the bonding strength is insufficient, and when the content of the adhesive component is more than 20 parts by mass, the smoothness of the overcoat layer may be impaired.

When using a water-soluble adhesive together, it is preferable to make the content into 4 mass parts or less especially per 100 mass parts of pigment components. When it exceeds 4 mass parts, since the smoothness of a coating layer falls, it is unpreferable. Using a small amount of water-soluble adhesives together with the dispersion type adhesive is effective for thickening and repairing the coating liquid that forms the coating layer.

The first coating liquid used for the formation of the undercoat layer and the second coating liquid used for the formation of the overcoat layer are, respectively, blue or purple dyes, colored pigments, fluorescent dyes, thickeners, and oxidation agents. Various preparations, such as an antioxidant, an anti-aging agent, an electrically conductive inducer, an antifoamer, a ultraviolet absorber, a dispersing agent, a pH adjuster, a mold release agent, a water-resistant agent, and a waterproofing agent, can be mix | blended suitably.

The coated paper coated with the second coating liquid in order to form the coated coating layer is provided in the finishing process, and in this process, for example, a super calender, a gross calender, a soft calender, or the like can be used, among them, a hard resin. It is preferable to employ a calendar provided with a roll.

In the present invention, the average particle diameter of the pigment component contained in the undercoat layer and the overcoat layer, respectively, is specified, and the undercoat layer and the overcoat layer are provided on one side or both sides of a relatively low bulk paper. Therefore, unless the press force is particularly high, calender finishes that are commonly used in the art can provide a printing vellum having a bulk density of 1.05 g / cm 3 or less.

(Example)

Although an Example is given to the following and this invention is concretely demonstrated to it, of course, this invention is not limited to them. In addition, unless otherwise indicated, the part and% in an example represent a mass part and mass%, respectively. In addition, the average particle diameter of the pigment used by the Example and the comparative example was measured with the following method.

Average particle diameter measurement of pigments by light scattering method

The particle size distribution of the pigment was measured using the laser diffraction type particle size distribution analyzer SALD-2000 made by Shimadzu Corporation, and the average particle diameter (d50 ₁ ) corresponding to 50 cumulative mass% was measured. In addition, the pigment dispersion liquid provided for the measurement was obtained by adding 0.05% of a dispersing agent (sodium polyacrylate) to a pigment, and diluting so that a pigment solid content concentration might be 1%. Moreover, it diluted to the area | region measurable by the said measuring apparatus as needed.

Average particle diameter measurement of pigments by sedimentation method

The particle size distribution of the pigment was measured using the Cedi Graph 5100 manufactured by the American Micromeritics Co., Ltd., and the average particle diameter (d50 ₂ ) corresponding to 50 cumulative mass% was obtained. In addition, the pigment dispersion liquid provided for the measurement is a pigment slurry prepared by adding 0.05% of a dispersant (sodium polyacrylate) to a pigment in a 0.1% aqueous solution of a phosphate-based dispersant (Nancarin) so that the pigment solid concentration is about 5%. Obtained by dilution.

Average particle diameter of copolymer latex

The sample containing copolymer latex was photographed by the transmission electron microscope at 50,000x magnification, the copolymer latex particle | grains were measured from the obtained microscope photograph, and it calculated | required by the number average.

Example 1

Preparation of the first escape solution (paint)

Diamine kaolin (trade name: Contour 1160, d50 ₁ : 2.7 μm, d50 ₂ : 0.38 μm, d50 ₁ / in an aqueous solution in which 0.1 part of sodium polyacrylate was added to the dispersed diamine kaolin as a dispersant). 90 parts of d50 ₂ : 7.1, manufactured by Imeris, and 10 parts of heavy calcium carbonate (trade name: hydrocurve 60, d50 ₂ : 1.3 μm, manufactured by Bihoku Honkago Co., Ltd.) were added in this order, and dispersed in a coreless disperser. Pigment slurry was prepared. To this slurry, 4.0 parts of oxidized starch (brand name: Ace B, manufactured by Ojikon Starch Co., Ltd.), styrene-butadiene copolymer latex (brand name: Smatex PA2182-2, particle size: 100 nm, Nihon A & L) 10 parts (in terms of solid content) of a sacher), and also an antifoaming agent and dye were added as a preparation, and finally, the 1st coating liquid of 54% of solid content concentration was prepared.

Preparation of the second coating liquid (paint)

To the aqueous solution which added 0.1 part of sodium polyacrylate as a dispersing agent with respect to the pigment to disperse, as a pigment, 80 parts of fine kaolins (brand name: chao gross, d50 ₂ : 0.4 micrometer, product made by Huber Corporation, USA), and heavy calcium carbonate (brand name) : Hydro curve 90, d50 _2: was added as 0.8㎛, protection ku hunka syaje Kogyo) 20 parts order, and distributed to the core-less dispersing machine to prepare a pigment slurry. To this slurry, 2 parts of oxidized starch (trade name: Oji Ace B, above), styrene-butadiene copolymer latex (brand name: Smatex PA2323, acrylonitrile monomer content: 21% by mass, particle size) to 100 parts of pigments: 89 nm, manufactured by Nippon A & L Co., Ltd., 12 parts (in terms of solid content), and an antifoaming agent and a dye were added as a preparation, and finally a second coating liquid having a solid content concentration of 59% was prepared.

Manufacture of printing paper

The first coating liquid is coated on both sides of a good quality paper having a bulk density of 0.73 g / cm 3 (a basis weight of 72.5 g / m 2) using a blade coater so as to have a dry weight of 6 g / m 2 per single side, which is dried and coated. The layer was set up. Subsequently, the said 2nd coating liquid was coated on each undercoat layer using the bleed coater so that the dry weight per single side might be 9 g / m <2>, and it dried and provided the overcoat layer. The paper thus obtained was passed through a super calender at a temperature of 35 ° C. and a linear pressure of 80 KN / m to obtain a printing paper of a bulk density of 1.03 g / cm 3.

Example 2

The pigment component of the second coating solution used in Example 1 was prepared by using 80 parts of fine kaolin (trade name: chaogrose, above), 10 parts of heavy calcium carbonate (trade name: hydro curve 90, above), and satin white (brand name: satin). White B, d50 ₂ : 1.0 µm, manufactured by Shiraishi Kogyo Co., Ltd., was changed to a pigment component, and the same as Example 1 was used except that the coating liquid had a final solid concentration of 54%.

Example 3

The pigment component of the first coating liquid used in Example 2 was delaminated kaolin (trade name: Contour 2070, d50 ₁ : 2.1 μm, d50 ₂ : 0.47 μm, d50 ₁ / d50 ₂ : 4.5, manufactured by Imeris Co., Ltd.) ) Example 2, except that 90 parts and heavy calcium carbonate (trade name: Hydrocurve 60, d50 ₂ : 1.3 μm, above) were changed into a pigment component, and a coating liquid having a final solid concentration of 54% was used. In the same manner as in the above, a printing paper was obtained.

Example 4

The pigment component of the first coating liquid used in Example 2 was delaminated kaolin (trade name: Contour 2000, d50 ₁ : 3.6 µm, d50 ₂ : 0.47 µm, d50 ₁ / d50 ₂ : 7.7, Imeris) Manufactured) in the same manner as in Example 2 except that it was changed to a pigment component consisting of 90 parts and 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above), to give a final liquid concentration of 54%. Obtained shelter.

Example 5

The pigment component of the first coating liquid used in Example 2 is a pigment component consisting of 60 parts of delaminated kaolin (trade name: Contour 2070, above) and 40 parts of heavy calcium carbonate (trade name: hydro curve 60, above). A vellum for printing was obtained in the same manner as in Example 2, except that the resultant was changed to a final coating liquid of 54% solid concentration.

Example 6

The pigment component of the first coating liquid used in Example 2 is a pigment component consisting of 90 parts of delaminated kaolin (trade name: Contour 1160, above), and 10 parts of heavy calcium carbonate (trade name: hydro curve 90, above). A vellum for printing was obtained in the same manner as in Example 2, except that the resultant was changed to a final coating liquid of 54% solid concentration.

Example 7

0.1 parts of oxidized starch (trade name: Oji Ace B, above), 12 parts of styrene-butadiene copolymer latex (brand name: Smatex PA2182-2, above) were used for the adhesive component of the first coating liquid used in Example 2. In the same manner as in Example 2, except that the solid content was converted into a coating liquid having a final solid concentration of 54%.

Example 8

The pigment component of the first coating liquid used in Example 2 was delaminated kaolin (trade name: Contour 1160, above), 80 parts, heavy calcium carbonate (trade name: Hydrocurve 60, above), satin white ( Brand name: Satin white B, said) The printing tract paper was obtained like Example 2 except having changed into the pigment component which consists of 10 parts, and made into the coating liquid of 53% of the final solid concentration.

Example 9

The adhesive component of the second coating liquid used in Example 8 was prepared by adding 2 parts of oxidized starch (trade name: Oji Ace B, above), styrene-butadiene copolymer latex (trade name: T-2629M, acrylonitrile monomer content: 17% by mass). A printing vellum was obtained in the same manner as in Example 8 except that the average particle diameter was changed to 12 parts (in terms of solid content) of 12 parts of 125 nm, manufactured by JS-Al.

Example 10

The pigment component of the second coating liquid used in Example 8 was prepared by using 80 parts of fine kaolin (brand name: chaogrose, above), 10 parts of heavy calcium carbonate (brand name: hydro curve 90, above), and plastic pigment (brand name: AE851). , d50 ₂ : 1.1 µm, porosity 50%, manufactured by JSR Corporation, and changed into a pigment component, except that the coating liquid was finally used as a coating liquid having a final solid concentration of 54%.

Example 11

The pigment component of the first coating solution used in Example 8 was 60 parts of delaminated kaolin (trade name: Contour 1160, above), 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above), and satin white. (Evening name: Satin White B, above) A printing dope was obtained in the same manner as in Example 8 except that it was changed to a pigment component consisting of 30 parts and used as a coating solution having a final solid concentration of 44%.

Example 12

In the preparation of the printing paper for example 8, the printing paper was obtained in the same manner as in Example 8 except that the coating amount (dry weight per side) of the coating layer was 9 g / m 2.

Example 13

The pigment component of the first coating liquid used in Example 2 was delaminated kaolin (trade name: Contour 1160, above), 80 parts of heavy calcium carbonate (trade name: hydro curve 90, above), and satin white. (Product name: Satin White B, above) was changed into a pigment component consisting of 10 parts, to prepare a coating liquid having a final solid concentration of 53%. Subsequently, in the production of printing paper, the bulk density was 0.67 g / cm 3. Except for using a good quality paper (basic weight 70.0g / ㎡) in the same manner as in Example 2 to obtain a printing paper.

Comparative Example 1

The pigment component of the first coating solution used in Example 2 was 90 parts of delaminated kaolin (trade name: Contour 1160, above), and heavy calcium carbonate (trade name: B21, d50 ₂ : 2.1 µm, Oji Seiyoshi Nago. A vellum for printing was obtained in the same manner as in Example 2 except that the constituent was changed to a pigment component consisting of 10 parts and a coating liquid having a final solid concentration of 54%.

Comparative Example 2

The pigment component of the first coating liquid used in Example 2 was d-laminated kaolin (trade name: capim NP, d50 ₁ : 3.7 µm with d50 ₁ of 3.7 µm, d50 ₂ of 0.95 µm, and d50 ₁ / d50 ₂ of 3.9). , d50 ₂ : 0.95 µm, d50 ₁ / d50 ₂ : 3.9, manufactured by Imeris, and a pigment component consisting of 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above), followed by a final solid concentration 54 Except for using the coating solution in%, it was carried out in the same manner as in Example 2 to obtain a printing coating paper.

Comparative Example 3

The pigment component of the first coating liquid used in Example 2 was delaminated kaolin (trade name: Capim DG, d50 ₁ : 2.3 µm, d50 ₂ : 0.61 µm, d50 ₁ / d50 ₂ : 3.8, manufactured by Imeris) The same as Example 2 except for changing to a pigment component consisting of 90 parts and 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above) and using a final solid concentration of 54% Got it.

Comparative Example 4

The pigment component of the first coating liquid used in Example 2 was delaminated kaolin (trade name: New Surf, d50 ₁ : 5.6 μm, d 50 ₂ : 2.1 μm, d50 ₁ / d 50 ₂ : 2.7, manufactured by Engel Hard Company) 90 A vellum for printing was obtained in the same manner as in Example 2, except that the constituent was changed to a pigment component consisting of 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above), and a coating liquid having a final solid concentration of 54%. .

Comparative Example 5

90 parts of the pigment component of the first coating liquid used in Example 2 was fine kaolin (trade name: Miragloss, d50 ₁ : 1.8 μm, d50 ₂ : 0.24 μm, d50 ₁ / d50 ₂ : 7.5, manufactured by Engel Hard Co., Ltd.); A vellum for printing was obtained in the same manner as in Example 2, except that it was changed to a pigment component consisting of 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above) and used as a coating solution having a final solid concentration of 54%.

Comparative Example 6

The pigment component of the first coating liquid used in Example 2 was engineered kaolin (trade name: ecyclone, d50 ₁ : 2.4 μm, d50 ₁ was 2,4 μm, d50 ₂ was 0.61 μm, d50 ₁ / d50 ₂ was 3.9). d50 ₂ : 0.61 µm, d50 ₁ / d50 ₂ : 3.9, manufactured by Engel Hard Co., Ltd., and 90 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above), which was changed to a pigment component containing a final solid concentration of 54%. Except for using the coating solution in the same manner as in Example 2, a printing coating paper was obtained.

Comparative Example 7

In the pigment component of the first coating liquid used in Example 5, 30 parts out of 60 parts of the delaminated kaolin (trade name: Contour 2070, above) were changed to fine kaolin (trade name: Miragrose, above), and finally, A vellum for printing was obtained in the same manner as in Example 5, except that the effluent liquid had a solid concentration of 54%.

Example 14

The adhesive component of the first coating liquid used in Example 2 was prepared by adding 8 parts of oxidized starch (trade name: Oji Ace B, above) and 8 parts of styrene-butadiene copolymer latex (trade name: Smatex PA2182-2, above). In the same manner as in Example 2, except that the solid content was converted into a coating liquid having a final solid concentration of 54%.

Comparative Example 8

Preparation of Assembled Satin White Pigment Slurry

90 kg (90 liters) of water was put into a 250-liter reaction tank (coreless stirring tank), and it did not carry out classification process, stirring this, and the thing of the size of diameter 1-4 cm is mixed. ) 10 kg of bulky lime (CaO, manufactured by Adachi Seika Co., Ltd.) was added thereto. Subsequently, it stirred, continuing stirring, the temperature of the liquid was raised, and after hold | maintaining in the range of 85-95 degreeC for 1 hour, it cooled to 30 degreeC. Subsequently, 58.3 kg of an aqueous solution of sulfuric acid band (dissolved in 25 kg of Al ₂ (SO ₄ ) ₃ .18H ₂ O) with respect to 50 kg (50 liters of water) of sulfuric acid bands was further stirred. The solution was added slowly to obtain a satin white suspension.

The suspension was wetted with a filter press to give a cake-shaped satin white having a solid content concentration of 32%. Next, 3 parts of sodium polycarboxylic acid (brand name: Aaron T-40, product made by Toagosei Co., Ltd.) and water are added per 100 parts of solid content of this satin white to a solid content concentration of 20%, and passed through a sand grinder to disperse the satin white dispersion. The dispersion was subjected to a screen mesh of 150 mesh to obtain a satin white pigment slurry having a solid content concentration of 20%. The average particle diameter by X-ray transmission type particle size distribution measurement of satin white obtained from this pigment slurry was 3.0 micrometers.

The pigment component of the first coating liquid used in Example 2 was obtained from 80 parts of delaminated kaolin (trade name: Contour 1160, above), 10 parts of heavy calcium carbonate (trade name: hydrocurve 60, above), and A vellum for printing was obtained in the same manner as in Example 2 except that the constituent was changed to a pigment component consisting of 10 parts of granulated satin white, and the final liquid concentration was 53%.

Example 15

The pigment component of the second coating liquid used in Example 2 was prepared by using 10 parts of fine kaolin (brand name: chaogrose, above), 80 parts of heavy calcium carbonate (brand name: hydro curve 90, above), and satin white (brand name: satin). White B and the above) were changed to the pigment component consisting of 10 parts, and the same as Example 2 except that the coating solution had a final solid concentration of 59%.

Example 16

The pigment component of the first coating solution used in Example 15 was delaminated kaolin (trade name: Contour 1160, above), 80 parts of heavy calcium carbonate (trade name: hydro curve 90, above), and satin white. A vellum for printing was obtained in the same manner as in Example 15 except that the constituent was changed into a pigment component consisting of 10 parts (brand name: Satin White B, above) and the final liquid concentration was 59%.

Comparative Example 9

The pigment component of the first coating liquid used in Example 15 was changed to a pigment component consisting of 90 parts of delaminated kaolin (trade name: Capim NP, above) and 10 parts of heavy calcium carbonate (trade name: hydrocurve 60, above). In addition, except for using the coating liquid of the final solid concentration of 54%, printing paper was obtained in the same manner as in Example 15.

Comparative Example 10

The pigment component of the first coating liquid used in Example 15 was changed to a pigment component consisting of 90 parts of fine kaolin (trade name: Miragros, above) and 10 parts of heavy calcium carbonate (trade name: Hydrocurve 60, above), and A vellum for printing was obtained in the same manner as in Example 15 except that the bleeding liquid having a typical solid concentration of 54% was used.

Quality Evaluation of Printed Sludge Paper

The quality of each printing dope paper obtained in Examples 1-16 and Comparative Examples 1-10 was evaluated by the following item. Evaluation was performed in 23 degreeC and 50 RH% environment unless there is particular notice. The results are shown in Tables 1 to 4.

PPS smoothness of shedding paper

Using a Parker Print Surf (PPS) surface smoothness tester (model name: MODEL M-569, manufactured by MESSMER BUCHEL, UK), the smoothing measurement was performed 5 times at a backing disk: soft rubber and clamp pressure: 0.98 MPa, and the average was measured. Obtained. Smoothness was performed after installing the undercoat layer, after installing the overcoat layer, and three points after calender finishing, respectively.

Surface smoothness

The surface of the coating layer after the final calender finish was visually observed, and smoothness was evaluated in four steps.

(Double-circle): Smoothness is especially excellent.

(Circle): It is excellent in smoothness.

(Triangle | delta): Smoothness falls slightly.

X: Smoothness is inferior.

· Stroke on the surface of escape layer

The surface of the coated layer of calendered hides was visually observed and the presence or absence of streaks was examined.

○: no streaking.

(Triangle | delta): There is a streak.

White paper gloss

Glossiness of each vellum before and after calendering process according to TAPPI test method: T 480 om-92 (TAPPI Test Method T 480 om-92), and a gloss meter (type: GM-26D, Murakami Shikisai Kijutsu Kenkyu Shosha Co., Ltd.) Was measured.

Printability (ink landing properties, and print smoothness)

Using an RI printer, 0.1 cc of printing ink (trade name: Values-G ink S type, manufactured by Dainippon Ink Kigaku Kogyo Co., Ltd.) was used for printing on each torn paper, and the ink transfer surface of the torn paper was visually observed and transferred. At the ink concentration (ink inkability) and the uniformity of the concentration (print smoothness), the printability of the vellum paper was evaluated in four steps.

(Double-circle): Printability is especially excellent.

(Circle): It is excellent in printability.

(Triangle | delta): Printability is inferior.

X: Printability is inferior.

· Print gloss

A printing ink (trade name: Values-G ink S type, manufactured by Dainippon Ink Kigakusha Co., Ltd.) was printed on each of the toner papers using 0.7 cc, and the printed matter was left to dry for 24 hours. Then, 60 degree glossiness of the printing surface of each torn paper was measured based on JISZ8741-1997.

Bulk density

The bulk density of the printing paper and the paper after calendering was measured in accordance with the provisions of ISO 534: 1988.

The printing vellum according to the present invention has a bulk density of 1.05 g / cm 3 or less, which is bulky and excellent in smoothness. Therefore, printing on this can produce a printing paper having a good appearance.

Claims (10)

A bulk coating paper having a density of 1.05 g / cm3 or less, provided with two layers of coating layers containing a white pigment component and an adhesive component on at least one side of a base paper having a bulk density of 0.75 g / cm3 or less, wherein the undercoat is in contact with the overcoat layer. The range of 10-20 mass parts per 100 mass parts of pigment components in which all of the pigment components contained in a layer are comprised by the dilaminated kaolin prescribed | regulated below, and the quantity of the adhesive component of an undercoat layer is contained in a undercoat layer A printable shelter, characterized in that. Delaminated kaolin: The average particle diameter (d50 ₁ ) measured by the light scattering method is in the range of 2.0-5.0 micrometers, and the average particle diameter (d50 ₂ ) measured by the sedimentation system exists in the range of 0.30-0.55 micrometer, Furthermore, the average particle Delaminated kaolin having a ratio (d50 ₁ / d50 ₂ ) of a diameter (d50 ₁ ) to an average particle diameter (d50 ₂ ) of 4 or more. A bulk coating paper having a density of 1.05 g / cm3 or less, provided with two layers of coating layers containing a white pigment component and an adhesive component on at least one side of a base paper having a bulk density of 0.75 g / cm3 or less, wherein the undercoat is in contact with the overcoat layer. 50 mass% or more of the pigment component contained in the layer is a delaminated kaolin as defined in claim 1, and the other is a white pigment, and the average particle diameter measured by the sedimentation method of this white pigment is 0.1-1.3 micrometer. In the range, the amount of the adhesive component of the undercoat layer is in the range of 10 to 20 parts by mass per 100 parts by mass of the pigment component contained in the undercoat layer. 3. The printing paper sack paper according to claim 2, wherein 1 to 30% by mass of the pigment component contained in the undercoat layer is satin white. The printing dope according to claim 1 or 2, wherein the adhesive component of the undercoat layer contains a dispersible adhesive, and the dispersed particle diameter is in the range of 50 to 120 nm. The adhesive component of the said undercoat layer consists of a water-soluble adhesive and a dispersible adhesive, and the quantity of a water-soluble adhesive is 7 mass parts or less per 100 mass parts of pigment components contained in a undercoat layer. Characterized by the printing paper. 3. The printing escort paper according to claim 1 or 2, wherein the PPS smoothness of the surface of the undercoat layer is in the range of 2.0 to 3.5 µm. The pigment component included in the overcoat layer is a white pigment, and the average particle diameter measured by the sedimentation method of the white pigment is in the range of 0.1 to 1.3 µm, The amount of the adhesive component is in the range of 10 to 20 parts by mass per 100 parts by mass of the pigment component contained in the overcoat layer. The printing dope according to claim 1 or 2, wherein the pigment component contained in the overcoat layer contains 1 to 30% by mass of satin white. The printing dope according to claim 1 or 2, wherein the pigment component contained in the overcoat layer contains 1 to 30% by mass of plastic pigment. The method of claim 1 or 2, wherein the adhesive component of the overcoat layer is composed of a water-soluble adhesive and a dispersible adhesive, and the amount of the water-soluble adhesive is 4 parts by mass or less per 100 parts by mass of the pigment component contained in the overcoat layer. Characterized by the printing paper.