JP2578069B2 - Coated printing paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated printing paper, and more particularly to a coated printing paper having a good ink receptivity and excellent texture.

[0002]

2. Description of the Related Art Paper is made of pulp fibers and has many voids due to the entanglement of the fibers, so that when printed, ink receptivity is poor and dropping occurs. Therefore, coating on paper is generally performed as a method for improving printability of paper.

[0003] In this method, a coating liquid comprising a filler such as clay, calcium carbonate, titanium oxide, etc. and an adhesive for fixing the filler to the paper is applied to paper as a base material, dried, and further subjected to mechanical processing such as calendering. This is a treatment to improve smoothness.

[0004] In this way, the printability is improved by filling and smoothing the voids on the paper surface with a chemical.

[0005] These have been commercialized in various forms from heavy-weight coated paper called art paper to finely-coated paper, and have occupied a large share with the recent visualization, colorization and upgrading of printing paper. ing.

[0006] However, general coated printing paper is functionally superior in pursuit of printability, but due to the above treatment, the original texture and texture of the paper is lost, and inorganic texture such as kaolin clay and calcium carbonate is lost. Will be.

The feel and texture are representative of the delicate unevenness and undulation of the surface, the lightness, the surface without shine, and the natural feeling and touch of pulp fibers.

[0008] The coated paper has a significantly improved white paper gloss and printed gloss on the coated surface due to the smoothing treatment of the coated surface.

In particular, glossy coated paper having high gloss has a small gradation due to a small difference in gloss between a blank portion and a printed portion, and has poor light incidence,
In many cases, the printed matter shines hard to see due to the degree of reflection.

[0010] Unless smoothing such as calendering is performed after coating and drying the coating liquid on the paper, the texture of the base paper is left, the paper is not hardened, and the texture is low and the texture is low. It becomes paper.

However, inorganic materials such as clay and calcium carbonate are used in conventional coated paper. However, since these fillers are hard and have poor cushioning properties, the undulation and roughness left on the surface cause the protrusions on the paper surface to become uneven. , But ink is not applied to the concave portions, and the printability is not improved.

Therefore, a smoothing process such as a calendar is indispensable in preparing a coated paper.

[0013] For the above reasons, coated printing paper having a good feeling cannot be obtained, and uncoated paper must be used to determine the feeling.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coated printing paper having good printability and excellent feeling and texture in view of the above situation.

[0015]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, an organic filler is present in at least one surface of a base material in a coating layer, and the cushioning property of the organic filler has The present inventors have found that a coated paper having excellent ink receptivity can be obtained without using a mechanical treatment after coating and drying to improve the smoothness of the coated layer, thereby completing the present invention.

That is, the coated printing paper of the present invention has a coating layer containing an organic filler on at least one surface of a substrate, and has a coating surface having a surface roughness RMax of 20 to 100 μm.

Hereinafter, the present invention will be described.

The organic filler is mainly composed of a synthetic resin, for example, acrylonitrile-butadiene-styrene copolymer, styrene-acrylonitrile copolymer, polystyrene-styrene copolymer, polypropylene resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, Examples include vinyl copolymer and urea formalin resin.

The coating layer containing an organic filler which is rich in elasticity, easily deformed, and has good resilience after pressure release has a higher cushioning property than inorganic fillers such as clay and calcium carbonate.

A hollow organic filler having a hollow structure is an organic filler which can further improve the cushioning property.
It is composed of a shell part and a gas-filled part, and has an average particle size of 0.1.
Spherical bodies having a diameter of 8 to 6 μm and an inner diameter of 0.6 to 0.9 times the outer diameter are mainly used, and examples thereof include hollow organic fillers such as polystyrene / styrene copolymers and styrene acrylonitrile copolymers.

The hollow organic filler is produced as a water-soluble dispersion, and the filler dispersed in the aqueous solution is in a state of being filled with water. After drying, the water is dispersed in the shell and the inside is filled with air. As compared with the hollow type, the shape is more easily deformed and the cushioning property is increased.

Similarly, in order to further improve the cushioning property, there is a method of foaming a coating layer containing an organic filler and dispersing fine bubbles in the coating layer.

The organic filler has characteristics of good ink receptivity and low apparent specific gravity. Therefore, a coating layer containing an organic filler is rich in cushioning properties and ink receptivity, and forms a low-density coating layer.

Although the cushioning property is not as high as that of a synthetic polymer organic filler, cellulose fine powder can be added as an organic filler (Japanese Patent Laid-Open No. 5-86598).

However, the organic filler is excellent in ink receptivity and cushioning property, but when added in a high amount due to the characteristics of the polymer as a component, gloss increases without a smoothing treatment,
The feeling tends to decrease. For this reason, it is more preferable to use together with another coating filler.

The coating filler used in combination is not particularly limited, and is generally coated printing paper such as kaolin clay, light calcium carbonate, heavy calcium carbonate, satin white, talc, barium sulfate, aluminum hydroxide, titanium oxide and the like. The inorganic fillers used for the above are preferably used.

The coating filler used in the coating layer of the present invention is prepared by mixing the organic filler and, if necessary, the inorganic filler.

At this time, the organic filler is 15 to 80 parts by weight, preferably 15 to 50 parts by weight based on 100 parts by weight of the total filler.
The rest is inorganic filler.

When the amount of the organic filler is less than 15 parts by weight, the cushioning property of the coating layer is insufficient and the roughness of the coated surface cannot be absorbed. This is because the texture is high and the texture is deteriorated.

The coating liquid comprises, as main components, a filler and an adhesive (binder) for fixing the filler to paper.

As the adhesive used for the coating solution, known adhesives can be used, for example, oxidized starch, etherified starch, esterified starch, enzyme-modified starch, casein, polyvinyl alcohol, styrene-butadiene, styrene-acrylic Latex resins composed of various polymers or copolymers, such as methacrylate, methyl acrylate, and vinyl acetate, can be appropriately selected and used alone or in combination of two or more.

The adhesive is 10 to 3 parts per 100 parts by weight of the filler.
0 parts by weight may be added. At this time, if necessary, a coating aid such as a crosslinking agent, an antifoaming agent, a thickener, or a waterproofing agent can be used.

For the preparation of the coating liquid, a mixer such as various mixers, kneaders and ball mills can be appropriately used according to the composition of the coating liquid.

In the coated paper of the present invention, a coating solution is applied to both sides or one side of a base paper for coating as a base material. The coating liquid can be applied by appropriately using a known coating apparatus with an air knife coater, a roll coater, a bar coater, a rod coater or the like.

The coated paper of the present invention is obtained by drying after coating, and the coated paper of the present invention is mechanically processed by a mechanical treatment such as a calendering treatment for improving printability like general coated paper. Does not smooth the surface.

The amount of coating on one side is 3 to 3% by dry weight.
20 g / m ^2, preferably in the range of 5 to 10 g / m ^2. Excessive coating causes a reduction in feeling and texture, and is not economically preferable, and a coating effect of less than 3 g / m ² cannot be obtained.

Next, FIG. 1 is a schematic view showing the deformation of the coating layer 3 due to the pressure when the kaolin clay 1 and the hollow organic filler 2 are mixed.

The coated paper obtained by applying the coating liquid using the coating apparatus and drying the coated liquid has a very low cushioning property as compared with a coated paper comprising only inorganic filler due to the cushioning property of the organic filler. And the ink is deformed by the printing pressure received from the impression cylinder during printing, so that ink receptivity is good even when the surface is rough (FIG. 1).

For this reason, after the coating liquid is applied to the base paper, mechanical smoothing such as calendering is not performed, and the surface roughness is 20 to 10%.
It shows excellent printability even at 0 μm, which is the same level as ordinary uncoated paper.

In addition to using the organic filler and the inorganic filler as a mixture, as shown in FIG. 2, a cushion layer 5 made of an organic filler and another coating filler, for example, an inorganic filler alone or an inorganic filler and an organic filler are used. By providing a coating layer in which the printing layer 6 composed of the filler is laminated to form a multilayer structure, the cushioning property of the organic filler can be used more effectively.

As shown in FIG. 1, when the organic filler and the inorganic filler are mixed, the gap between the organic filler particles is filled with the inorganic filler and the cushioning property of the organic filler particles is hardly exhibited.
In order to improve the cushioning property of the entire coating layer, a relatively high amount of organic filler is added.

The increase in gloss due to an increase in the amount of the organic filler can be solved by laminating the organic filler and the inorganic filler without mixing them.

First, an organic filler is applied as a cushion layer on a substrate, and then a printed layer made of an inorganic filler is overcoated on the upper layer. If necessary, a coating layer having a higher cushioning property can be formed by adding an organic filler to a printing layer made of an inorganic filler.

The cushion layer is composed of an organic filler and an adhesive. The adhesive used for the coating liquid can be used alone or as a mixture of two or more by appropriately selecting the above adhesive.

The adhesive is 10 parts by weight based on 100 parts by weight of the organic filler.
It may be added up to 30 parts by weight. At this time, if necessary, a coating aid such as a crosslinking agent, an antifoaming agent, a thickener, or a water-proofing agent can be used, and can be used as appropriate. For preparing the coating liquid, a stirrer such as various mixers, kneaders, ball mills and the like can be appropriately used according to the composition of the coating liquid.

The printing layer is mainly composed of an inorganic filler,
The inorganic filler used for the printing layer is kaolin clay, light calcium carbonate, heavy calcium carbonate, satin white,
Fillers used for general coated printing paper such as talc, barium sulfate, aluminum hydroxide, and titanium oxide can be used.

The above-mentioned organic filler can be added to the print layer as needed to further improve the cushioning property, to enhance the color development of the ink, and to adjust the surface gloss. As in the case of mixing, addition of a fine cellulose powder up to 20% by weight (Japanese Patent Laid-Open No. 5-86598) is also possible.

As the adhesive used for the coating liquid, the above-mentioned adhesives can be appropriately selected and used alone or in combination of two or more.

The printing layer adhesive may be added in an amount of 10 to 30 parts by weight per 100 parts by weight of the filler. At this time, if necessary, a coating aid such as a crosslinking agent, an antifoaming agent, a thickener, or a water-proofing agent can be used, and can be used appropriately.

For the preparation of the coating liquid, a stirrer such as various mixers, kneaders and ball mills can be used as appropriate according to the composition of the coating liquid.

In order to provide a multi-layer coating layer comprising a cushion layer and a printing layer, a coating liquid comprising an organic filler is applied and then dried, and then a cushion layer is first provided, and an inorganic filler and an organic filler as a printing layer are formed thereon. A coating paper is obtained by coating and drying the coating liquid comprising the following to form a coating layer.

Also in this case, the coating layer is deformed by the printing pressure received from the impression cylinder during printing due to the cushioning property of the organic filler, and the printability is enhanced.

Similarly to the case where the organic filler and other coating fillers are mixed and coated, the coating liquid is not applied to the coating base paper and then mechanical smoothing such as calendering is not performed. 20-10
It shows excellent printability even at 0 μm, which is the same level as ordinary uncoated paper.

In the case of laminating, the coating liquid can be appropriately used by various known coating apparatuses such as an air knife coater, a roll coater, a bar coater and a rod coater.

[0055] The coating amount of the organic filler layer, 2 to 10 g / m ² by dry weight to the printing layer both preferably in the range of 3 to 5 g / m ^2. In this case, too, as in the case where the organic filler and other coating fillers are mixed and coated, excessive coating is not economically preferable, and if it is ² g / m ² or less, the feeling and texture are reduced, and the coating effect is obtained. Absent.

The coated paper thus obtained has a cushioning property of the organic filler layer, and at the time of printing, the coated layer is deformed by the pressure from the impression cylinder to increase the adhesiveness with the ink and to have a smooth coated surface. It shows very good printability at least.

In other words, the coated paper of the present invention is a coated surface having a large surface roughness with undulations and irregularities before printing, but the coated surface is deformed flat during printing and becomes a coated surface having high smoothness. Therefore, it is good as a coated printing paper having high printability without performing a step of mechanically smoothing the coated surface such as calendering after coating and drying.

As a raw material of paper as a base material used in the present invention, paper made of various wood pulp, non-wood pulp, and synthetic pulp, alone or in combination, can be used.

However, the coated paper of the present invention is characterized by a surface roughness, and the coated base paper used in the present invention is preferably a paper which has not been subjected to a calender treatment, and has a smoothness of 3 seconds or more and 20 seconds or less. It is.

The density of the base material not subjected to the calendering treatment is 0.60 to 0.75 g / cm ³ , and when applied to these base materials, the smoothing treatment is unnecessary because the organic filler is present in the coating layer. The density of the coated paper prepared by reducing the density of the coating layer is 0.60 to 0.8 which is the same as that of a normal uncoated paper.
0 g / cm ³ .

The density of the coated paper plays a large role in bookbinding. Conventional coated papers are in the range of 1.00 to 1.40 g / cm ³ , and when they are used for bookbinding, the finish becomes very heavy, and books that use a lot of coated paper such as art books are difficult to handle.

The basis weight is 133.3 g / m ² and the thickness is 107.5.
Taking an art-coated paper of μm and density of 1.240 g / cm ³ as an example, an A4 size book having a thickness of 40 mm weighs 3,093 g.

However, when the coated printing paper of the present invention is bound in the same manner, the weight is 2,000 g or less due to the above density, and the handling is extremely easy.

Further, in the coated paper of the present invention, the printability is enhanced by the cushioning property of the coating layer, but the cushioning property of the base paper for coating may be used.

The base paper is composed of pulp fibers. However, the bulk paper having many voids in the coated base paper and having a low density has a higher deformation ratio under pressure than the coated base paper. growing.

This is because a bulky raw material such as linter pulp is used, the beating of the raw material is weakened, no filler is added, the press pressure during papermaking is changed, and the cushioning property is increased. Paper can be made.

When such a paper is used as the base material, the cushioning properties of the paper are taken into account in addition to the cushioning properties of the coating layer, so that the printability is further improved. At the same time, the density of the coated base paper is 0.50
Since as low as 0.650 g / cm ^3, becomes more density of coated paper also 0.60~0.70g / cm ³ of the present invention a low density.

These are coated printing papers which have the same level as that of non-coated printing papers having a bulky texture and which have not been subjected to a smoothing treatment, and which have a texture which is not felt as a coated paper.

At this time, if the book is bound under the above conditions,
g or less, resulting in a lighter finish.

The cushioning property of the coated paper of the present invention can be measured by Parker Print Surf.

Parker print surf is an apparatus for obtaining smoothness from the amount of air flow in the same manner as Beck smoothness.
By applying pressure to the measuring head and measuring, the printing pressure of various printing presses is reproduced and the smoothness during printing is measured.

The measurement pressure can be adjusted in three steps of 5, 10, and 20 kg / cm ^{2. As} this pressure is increased, the paper tends to be crushed and the smoothness tends to increase.

Since the conventional coated paper is calendered, the measured value of Parker Print Surf Roughness at a low pressure of 5 Kg / cm ² is already as small as 5.0 μm or less, and 20 Kg / cm ^2. The measured value in cm ² is 2.0 to 4.0 μm, and the change due to pressure is 1.0 to 4.0 μm.
It has a width of only about 3.0 μm.

However, the coated paper of the present invention has a large amount of change due to pressure due to the cushioning property of the organic filler.

The measured value at 5 kg / cm ² was 6.0 to 8.0.
0 μm, which is the same level as ordinary uncoated paper,
The pressure of g / cm ² is compressed to less 2.0~4.5μm the same level as the coated paper mechanically smoothing process has been applied.

The hand and texture, which are the characteristics of the coated paper of the present invention, can also be expressed by the measured values of smoothness and gloss of white paper.

The coated paper of the present invention has a feeling and texture close to those of the uncoated paper, and has the same level of smoothness and blank gloss as the uncoated paper.

The undulations and irregularities on the coated surface are indicated by smoothness. General coated paper tends to be a little smoother to improve printability, and even coated paper with a relatively rough surface called matte coating has a smoothness of about 60 seconds, making it possible to apply art coating with a large amount of coating. In most cases, the time exceeds 1000 seconds.

However, since the coated paper of the present invention has the above-mentioned coating layer, it has a smoothness of 4 to 20 seconds and has a rough surface with undulations and irregularities, but has good printability. This smoothness is at the same level as the conventional uncoated printing paper, and has a very good feeling.

Since the mechanical smoothing treatment is unnecessary, the coated paper of the present invention has a white paper gloss of 1 to 15%, preferably 1 to 5%.
%.

In the coated paper of the present invention, the reflected light is dispersed due to the surface undulation and the surface roughness, and the glossiness is lowered.

Further, when a filler having a large particle size such as heavy calcium carbonate is added to the coating layer to increase the roughness of the coated surface, the glossiness is further reduced and becomes 1 to 5%.

This is a numerical value which is not different from the glossiness of ordinary uncoated paper, and is excellent in feeling and texture. Further, when printed, the glossiness of the white paper is low, so that the gloss difference between the white paper part and the printed part is large, and the printed matter is excellent in gradation.

A factor that affects the gloss of printed matter is oil absorption. The conventional coated paper is coated with a relatively large amount of coating liquid in order to smooth the coated surface, and because of the smoothing treatment, the coated layer is dense and has few voids and low oil absorption.

For this reason, the oil absorption of the conventional coated paper is small,
000 seconds, most of which are 5000 seconds or more. The coated paper of the present invention is not smoothened and has many voids in the coating layer, so that the oil absorption is large and the oil absorption is in the range of 30 seconds to 1000 seconds. Paper having a low oil absorption has good ink absorption, so that set-off after printing can be prevented.

As described above, the coated paper of the present invention is a coated printing paper having excellent feeling and texture.

[0087]

[Example 1] Hollow organic filler (Rohm & Haas Japan,
Esterified starch based on 20 parts by weight of Rho-Pake HP-91), 66.7 parts by weight of light calcium carbonate (Okutama Industries, Tamapearl TP-121), and 13.3 parts by weight of cellulose fine powder (Rettenmeier, Arbocel BE600 / 10) (Shikishima Starch, Mermaid MC3000) 4.
7 parts by weight, 14 parts by weight of styrene / butadiene latex (Sumitomo Nogatac, SN-307), 1 part by weight of polyamide resin (Sumitomo Chemical, Sumireze Resin 636), sodium polycarboxylate (Sanyo Chemical, Carribbon L400)
A coating solution consisting of 1 part by weight was prepared to prepare an aqueous solution having a solid content of 35.0%.

The coating solution was coated on a base paper having a basis weight of 151.2 g / m ² , a Beck smoothness of 5.1 seconds, and a density of 0.631 g / m ³ , each coated with 18 g / m ² (wet) on both sides, followed by drying. Coated paper was made.

[0089]

Example 2 <Preparation of Cushion Layer Coating Solution> Hollow Organic Filler (ROHM &
100 parts by weight of Haas Japan, Rope Ike HP-91) and esterified starch (Shikishima Starch, Mermaid M)
C3000) 7.5 parts by weight, methyl acrylate / butadiene latex (Takeda Pharmaceuticals, Closrene 2M45A)
A coating solution composed of 25 parts by weight and 1 part by weight of a polyamide resin (Sumitomo Chemical, Sumirezu Resin 636) was prepared to prepare an aqueous solution having a solid content of 26.7%.

<Preparation of Printing Layer Coating Solution> 60 parts by weight of kaolin clay (Hoover, Hydrafine 90), 25 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishi Hana PZ),
Heavy calcium carbonate (Toyo Kogyo, Whiten 109) 1
5 parts by weight, esterified starch (Shikishima starch, Mermaid MC3000) 5 parts by weight, methyl acrylate / butadiene latex (Takeda Pharmaceuticals, Closlen 2M45A) 1
A coating liquid comprising 6.7 parts by weight, 1 part by weight of a polyamide resin (Sumitomo Chemical Co., Sumirezu Resin 636) and 1 part by weight of sodium polycarboxylate (Sanyo Chemical, Cariblon L400) was prepared. A 2% aqueous solution was made.

First, the cushion layer coating solution was applied to a basis weight of 127.9.
g / m ² , Beck smoothness 8.1 seconds, density 0.722 g
18 g / m ² (wet) on one side was applied to the base paper of 1 g / m ³ and dried to prepare a coated paper.

Further, a coating solution for a printing layer was applied onto the coated paper so that the coating solution was laminated on the cushion layer at a rate of 15 g / m ² (wet) on one side.
Was coated and dried to prepare a coated paper having a two-layer structure.

[0093]

Example 3 <Preparation of Cushion Layer Coating Solution> Hollow Organic Filler (ROHM &
100 parts by weight of Haas Japan, Rope Ike HP-91) and esterified starch (Shikishima Starch, Mermaid M)
C3000) 5.7 parts by weight, styrene butadiene latex (Sumitomo Nogatack, SN-307) 22.9 parts by weight, and a polyamide resin (Sumitomo Chemical, Sumireze Resin 636) 1 part by weight was prepared. , Solid content 1
A 7.8% aqueous solution was made.

<Preparation of Printing Layer Coating Solution> 53 parts by weight of kaolin clay (Hoover, Hydrafine 90), 22 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishi Hana PZ),
Heavy calcium carbonate (Toyo Kogyo, Whiten 109) 1
3 parts by weight, 12 parts by weight of cellulose powder (Rettenmeier, Arbocel BE600 / 10), 4 parts by weight of esterified starch (Shikishima Starch, Mermaid MC3000), 12 parts by weight of styrene-butadiene latex (Sumitomo Nogatack, SN-307), A coating solution comprising 1 part by weight of a polyamide-based resin (Sumitomo Chemical, Sumirezu Resin 636) and 1 part by weight of sodium polycarboxylate (Sanyo Chemical, Carribbon L400) was prepared to prepare an aqueous solution having a solid content of 41.1%. .

The coating solution for the cushion layer was applied with a basis weight of 126.7 g /
m ² , Beck smoothness: 5.2 seconds, density: 0.609 g / m ³
Was coated and dried at 15 g / m ² (wet) on both sides to prepare a coated paper.

Further, 13 g / m ² (wet) of each side was coated and dried on the coated paper in such a manner that the coating liquid for the printing layer was laminated on the cushion layer to prepare a coated paper having a two-layer structure.

[0097]

Example 4 <Preparation of Cushion Layer Coating Solution> Hollow Organic Filler (ROHM &
100 parts by weight of Haas Japan, Rope Ike HP-91) and esterified starch (Shikishima Starch, Mermaid M)
C3000) 5.7 parts by weight, styrene butadiene latex (Sumitomo Nogatack, SN-307) 22.9 parts by weight, and a polyamide resin (Sumitomo Chemical, Sumireze Resin 636) 1 part by weight was prepared. , Solid content 1
A 7.8% aqueous solution was made.

<Preparation of Printing Layer Coating Solution> 100 parts by weight of kaolin clay (Hoover, Hydrafine 90), esterified starch (Shikishima Starch, Mermaid MC300)
0) 4 parts by weight, styrene-butadiene latex (Sumitomo Nogatack, SN-307) 12 parts by weight, polyamide resin (Sumitomo Chemical, Sumireze Resin 636) 1 part by weight, sodium polycarboxylate (Sanyo Chemical, Caribbean L4)
00) A coating solution consisting of 1 part by weight was prepared, and a solid content of 34.
A 6% aqueous solution was made.

The coating liquid for the cushion layer was applied with a basis weight of 126.7 g /
m ² , Beck smoothness: 5.2 seconds, density: 0.609 g / m ³
17 g / m ² (wet) on one side of base paper
Coated paper was made.

Further, a coating solution for a printing layer is laminated on the coated paper so as to be laminated on the cushion layer at 10 g / m ² (wet) on one side.
Was coated and dried to prepare a coated paper having a two-layer structure.

[0101]

Example 5 <Preparation of Cushion Layer Coating Solution> Styrene-butadiene latex (Sumitomo Nogatack, SN-307) 16 parts by weight with respect to 100 parts by weight of organic filler (Dainippon Ink and Chemicals, Grandl PP-1000) Parts, 1 part by weight of polyamide resin (Sumitomo Chemical, Sumirezu Resin 636), sodium polycarboxylate (Sanyo Chemical, Carribbon L400)
A coating solution consisting of 0.3 parts by weight was prepared and had a solid content of 23.5.
% Aqueous solution was made.

<Preparation of Coating Liquid for Printing Layer> 53 parts by weight of kaolin clay (Hoover, Hydrafine 90), 22 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishi Hana PZ),
Heavy calcium carbonate (Toyo Kogyo, Whiten 109) 1
3 parts by weight, 12 parts by weight of cellulose powder (Rettenmeyer, Arbocel BE600 / 10) and esterified starch (Shikishima starch, Mermaid MC3000)
4.1 parts by weight, 12.4 parts by weight of styrene-butadiene latex (Sumitomo Nogatack, SN-307), 1 part by weight of polyamide resin (Sumitomo Chemical, Sumireze Resin 636), sodium polycarboxylate (Sanyo Chemical, Carribbon) L
400) Prepare a coating solution consisting of 1 part by weight,
A 0.2% aqueous solution was made.

The coating solution for the cushion layer was applied with a basis weight of 126.7 g /
m ² , Beck smoothness: 5.2 seconds, density: 0.609 g / m ³
15 g / m ² (wet) on one side of base paper
Coated paper was made.

Further, a coating solution for a printing layer was applied to the coated paper so that the coating solution was laminated on the cushion layer at a rate of 15 g / m ² (wet) on one side.
Was coated and dried to prepare a coated paper having a two-layer structure.

[0105]

Example 6 75 parts by weight of an organic filler (Dainichi Seika, New Daifoam P-18) and 25 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishihana PZ) were added to a styrene-butadiene latex (Sumitomo Nogatack, SN-). 307) 1
A coating liquid consisting of 6 parts by weight, 1 part by weight of a polyamide resin (Sumitomo Chemical, Sumirezu Resin 636) and 1 part by weight of sodium polycarboxylate (Sanyo Chemical, Cariblon L400) was prepared, and a solid content of 23.5% was obtained. An aqueous solution was made.

The base material having a basis weight of 126.7 g / m ² , a Beck smoothness of 5.2 seconds and a density of 0.609 g / m ³ was coated with 15 g / m ² (wet) on one side and dried. Made paper.

The obtained coated paper was again subjected to 2 at 120 degrees.
After drying for minutes, a coated paper was prepared.

[0108]

Example 7: Organic filler (Mitsui Toatsu Chemicals, Grosdale 2)
Styrene-butadiene latex (Sumitomo Nogatack, SN-307) per 75 parts by weight of 04-S) and 25 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishi Hana PZ)
A coating liquid consisting of 6 parts by weight, 1 part by weight of a polyamide resin (Sumitomo Chemical, Sumirezu Resin 636) and 1 part by weight of sodium polycarboxylate (Sanyo Chemical, Cariblon L400) was prepared, and a solid content of 23.5% was obtained. An aqueous solution was made.

A base paper having a basis weight of 126.7 g / m ² , a Beck smoothness of 5.2 seconds and a density of 0.609 g / m ³ was coated with 15 g / m ² (wet) on one side and dried. Made paper.

[0110]

[Comparative Example 1] Hollow organic filler (Rohm & Haas Japan,
Low-Park OP-84J) 100 parts by weight of polyvinyl alcohol (Denka Poval K-1)
7E) A coating liquid comprising 6.0 parts by weight, 30 parts by weight of methyl acrylate / butadiene latex (Takeda Pharmaceutical Co., Ltd., 2M45A) and 1 part by weight of a polyamide resin (Sumitomo Chemical, Sumireze Resin 636) was prepared. 2
A 7.8% aqueous solution was made.

The coating solution was coated on a base paper having a basis weight of 127.9 g / m ² , a Beck smoothness of 8.1 seconds and a density of 0.722 g / m ³ at 18 g / m ² (wet) on one side, followed by drying. Made paper.

[0112]

Comparative Example 2 53 parts by weight of kaolin clay (Hoover, Hydrafine 90), 22 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishihana PZ), 13 parts by weight of heavy calcium carbonate (Toyo Kogyo, Whiten 109), cellulose powder (Rettenmeier, Arbocel BE600 / 1
0) 12 parts by weight, 5 parts by weight of esterified starch (Shikishima starch, Mermaid MC3000), methyl acrylate
Butadiene latex (Takeda Pharmaceutical, Closlen 2M45
A) A coating liquid comprising 16.7 parts by weight, 1 part by weight of a polyamide resin (Sumitomo Chemical Co., Sumirezu Resin 636) and 1 part by weight of sodium polycarboxylate (Sanyo Chemical, Carribbon L400) was prepared. A 1% aqueous solution was made.

The coating liquid was coated on a base paper having a basis weight of 127.9 g / m ² , a Beck smoothness of 8.1 seconds, and a density of 0.722 g / m ³ on one side of 18 g / m ² (wet), followed by drying. Made paper.

Further, a nip pressure of 1.7 Kg /
cm and a soft calendering treatment at 150 ° C.

[0115]

[Comparative Example 3] Hollow organic filler (Rohm & Haas Japan,
Low-Pake HP-91) 10 parts by weight, 90 parts by weight of light calcium carbonate (Shiraishi Kogyo, Shiraishi Hana PZ), esterified starch (Shikishima Starch, Mermaid MC3000) 5
Parts by weight, 20 parts by weight of methyl acrylate / butadiene latex (Takeda Pharmaceutical Co., Ltd., Closlen 2M45A), polyamide resin (Sumitomo Chemical, Sumirezuresin 636) 1
A coating solution consisting of parts by weight was prepared to prepare an aqueous solution having a solid content of 50.6%.

The coating solution was coated on a base paper having a basis weight of 119.8 g / m ² , a Beck smoothness of 6.9 seconds, and a density of 0.669 g / m ³ at 18 g / m ² (wet) on one side, followed by drying. Made paper.

[0117]

Comparative Example 4 Using the cushion layer coating liquid and the printing layer coating liquid used in Example 3, the coating liquid was weighed 84.1 g /
m ² , Beck smoothness 10.8 seconds, density 0.728 g /
20 g / m ² (wet) on both sides of a m ³ base paper was coated and dried to prepare a coated paper.

Further, the coated paper was coated with 20 g / m ² (wet) on both sides such that the coating liquid for the printing layer was laminated on the cushion layer, and dried to prepare a coated paper having a multilayer structure.

The obtained coated paper had a linear pressure of 1.0 kg /
cm and a temperature of 30 ° C.

Table 1 shows the structures of the examples and comparative examples.

A quality test was performed on the coated papers obtained in Examples and Comparative Examples. Table 2 shows the results obtained for Parker print roughness, printability, smoothness, density, surface roughness, hand and texture.

The printability was evaluated by performing solid printing using an RI tester of Meisho Seisakusho, the smoothness test was measured by the smoothness test method P8119 based on the Beck test of JIS paper and paperboard, and the density was measured by JIS paper and paperboard. Measured according to thickness and density test method P8118.
Measured by 75 ° specular gloss test method for paper and paperboard P8142, surface roughness RMax measured by JIS stylus type surface roughness meter B0651, Parker print roughness measured by soft backing using MESSMER PPS90, oil absorption Was measured in accordance with JIS paper and paperboard oil absorption test method P8130, and the feeling and texture were evaluated by sensory tests.

[0123]

[Table 1]

[0124]

[Table 2]

[0125]

As described above, the coated paper of the present invention is rich in ink receptivity and excellent in feeling even without being subjected to a mechanical smoothing treatment.

Therefore, according to the present invention, it has become possible to provide coated printing paper with excellent printability and excellent paper quality.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing deformation of a coating layer in which an organic filler and an inorganic filler are mixed due to pressure.

FIG. 2 is an explanatory diagram showing deformation due to pressure of a coating layer in which a printing layer is laminated on a cushion layer.

[Explanation of symbols]

 1 Kaolin clay 2 Hollow organic filler 3 Coating layer 4 Coating base paper 5 Cushion layer 6 Printing layer

Claims (7)

(57) [Claims] 1. A coating liquid in which an organic filler is 15 parts by weight or more and 80 parts by weight or less in 100 parts by weight of a total filler is coated on at least one surface of a substrate having a smoothness of 3 seconds or more and 20 seconds or less. Coated printing paper, provided with a coating layer having a surface roughness RMax of 20 μm or more and 100 μm or less. 2. Coated printing paper characterized in that the organic filler present in the coating layer formed on the base material is 15 to 80 parts by weight based on 100 parts by weight of the total filler. 3. The coated printing paper according to claim 1, further comprising a coating layer formed by laminating a printing layer containing an inorganic filler and an organic filler on the organic filler layer. 4. The coated printing paper according to claim 1, wherein an organic filler having a hollow structure is used as the organic filler. 5. The method according to claim 1, wherein the density is 0.60 g / c.
m ³ or more 0.80 g / cm ³ or less become coated printing paper. 6. The method according to claim 1, wherein the density is 0.60 g / c.
m ³ or more 0.70 g / cm ³ or less become coated printing paper. 7. A Parker print surfing with a blank gloss of 1% or more and 15% or less, a Beck smoothness of 4 seconds or more and 20 seconds or less, and a pressure of 5 kg / cm ² of 6.0 μm or more and 8.0 or more.
Parker print surfing at 2.0 μm or less and pressure of 20 kg / cm ² , 2.0 μm to 4.5 μm, oil absorption 30 seconds to 1000 seconds, density 0.60 g / c.
coated printing paper, characterized in that meet all m ³ or more 0.80 g / cm ³ or less.