JPH05106198A - Pigment coated paper for printing and method for producing the same - Google Patents

Abstract

(57) [Summary] [Object] To obtain a pigment-coated paper having excellent gloss and smoothness, a uniform coating layer and no coating defects in a pigment-coated paper for printing and a method for producing the same. [Structure] The coating liquid contains 3 parts by weight or more of delamination clay in a total amount of 100 parts by weight of pigment, and 80 to 100% by weight of the clay is particles having a particle diameter of 1 μm or more, which is curtain coated. Apply by the device. [Effect] By applying a coating liquid containing delamination clay by a curtain coating device, a coated paper excellent in gloss and smoothness can be obtained without coating defects due to the effect of clay orientation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment-coated paper for printing and a method for producing the same, and relates to printing in which a coating solution containing a pigment is applied to a continuously running strip-shaped substrate (hereinafter referred to as "web") TECHNICAL FIELD The present invention relates to a pigment-coated paper and a manufacturing method thereof. In particular, it relates to printing paper such as art and coated paper, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, pigment-coated paper has been used as a printing paper because it has higher smoothness and gloss than that of uncoated high-quality paper and has uniform ink absorption. Particularly in recent years, the visualization of printed matter has advanced, and the demand for printing paper has also diversified. Furthermore, there are various printing methods such as gravure, rotary offset, sheet-fed offset, etc., and printing paper having characteristics suitable for each printing method. Is under development. Under such circumstances, a demand for a coating technique for printing paper on which a pigment is coated is to obtain a product having excellent gloss, high surface smoothness, and no coating defects under high productivity.

There are various coating methods for printing paper for pigment coating, and specific examples thereof include a blade coating method, an air knife coating method and a roll coating method. However, in these coating methods, the type and shape of the pigment contained in the coating liquid must be restricted in consideration of the quality of the coated product and the stability of the process, and the pigment having a great effect on the quality improvement. However, it is difficult to obtain high quality printing paper.

That is, in the blade coating method, coating defects such as streaks and scratches are likely to occur in the coating operation. This tendency is particularly remarkable in the case of a coating liquid containing delamination clay having a flat shape. this is,
When the liquid is drawn into the narrow gap just below the tip of the blade, the clay is not oriented, the viscosity of the liquid increases, and streaks and scratches occur.

As described above, when streaks or scratches are generated, the generated portions are all wasted paper, which causes a large loss in terms of production efficiency and cost. Further, the occurrence of these defects becomes more remarkable as the coating speed becomes higher and the coating concentration becomes higher, which makes both improvement of production efficiency and improvement of quality incompatible.

Further, in such a coating method, since the water or the binder component in the coating liquid is excessively infiltrated into the web between the supply of the excess liquid and the measurement, the liquid scraped off as the excess liquid is It differs from the composition of the liquid before supply. Therefore, the composition of the coating solution changes with the passage of time, and a product of stable quality cannot be obtained.

In the air knife coating method, a pattern peculiar to the air knife is easily generated in the coating layer. As a result, the gloss and smoothness of the surface of the coating layer are significantly reduced, and not only the quality is degraded but also a serious obstacle during printing. This tendency becomes remarkable when the coating speed is increased or when the concentration of the liquid is increased, and the efficiency of production and the improvement of quality are not compatible with each other.

There are various types of roll coating methods depending on the combination of rolls and the like. Basically, a plurality of rolls are combined and the coating liquid is transferred between the rolls to measure the liquid and transfer it to the web. It is a coating method. Such a coating method easily generates a pattern peculiar to the roll, and
When the coated roll surface and the web are peeled off after transfer, the gloss and smoothness of the coated surface are deteriorated, which not only deteriorates the quality but also becomes a serious obstacle during printing. This tendency becomes remarkable when the liquid concentration or the coating speed is increased.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an air knife coating system, a blade coating system, a roll coating system,
A high-quality printing pigment has been achieved by using the curtain coating method to manufacture high-quality products by incorporating delamination clay, a special pigment that was not possible with To get coated paper.

[0010]

The present invention provides a pigment coated paper for printing comprising a coating layer containing a pigment as a main component and a method for producing the same, wherein the coating liquid for the coating layer has a total amount of the pigment of 100. Among the parts by weight, the delamination clay is contained in an amount of 3 parts by weight (hereinafter, “parts by weight” means an added part by weight when the total amount of the pigments is 100 parts by weight). Particles having a weight percentage of 1 μm or more,
It was found that by applying the coating solution using a curtain coating device, streak which frequently occurs in rod coating or blade coating is eliminated, and a coated surface with high gloss and smooth and uniform coating amount can be obtained. It is a thing.

The characteristic of the curtain coating system is that, as can be seen from FIG. 1 or FIG. 2, the place where the liquid flows in a regulated flow path is only the slit 2. The width of this slit can be selected in a wide range, but normally 0.2 mm ~
It is between 1 mm. In curtain coating, the liquid flowing out from the lip 3 forms a free surface until it comes into contact with the web 5, so the flow path is not regulated. On the other hand, in the rod or blade coating method, the minimum gap between the rod or blade and the web where liquid is measured is usually 0.0
It is 5 mm or less. Therefore, when aggregates or foreign substances are present in the liquid, the probability of appearing as streaks is much lower in the curtain coating method than in the rod or blade coating method.

Since the curtain coating method is a pre-metering type coating method, the amount of the liquid flowing out from the head is collected and used in a small amount. On the other hand, since the rod or blade coating method is a post-measurement type coating method in which the liquid is once excessively supplied to the web and then scraped off and measured, the amount of collected liquid is smaller than that of curtain coating. Many. In addition, in the rod and blade coating method, when excess liquid is supplied to the web, water and binder in the liquid selectively absorb it to increase the concentration of the recovered liquid and increase the concentration of the coating liquid. Foreign matter adhering to the surface accompanies the collected liquid and causes streaks. On the other hand, in the curtain coating method, stable coating can be performed without changing the concentration of the coating liquid even during long-term operation.

The curtain coating method is a pre-metering type coating apparatus as described above, and since the coating solution is not scraped off at the time of coating, the coating solution is a very uniform so-called contour coating layer along the surface shape of the web. To form. In particular, when coated on a web having excellent smoothness, it is possible to obtain an ideal pigment-coated paper for printing, which is excellent in smoothness of the coated surface and uniformity of coating amount.

On the other hand, in the rod-and-blade coating method, the coating amount is excessive in the concave portions of the web and insufficient in the convex portions as opposed to the irregularities of the web, resulting in uneven printing in the printing after plate making. appear. Further, in the roll coating method, when the roll and the coating surface are separated from each other, the coating surface is likely to be disturbed, it is basically difficult to obtain a uniform coating amount, and the surface smoothness is poor. This tendency becomes more remarkable when the solid content concentration of the coating liquid is high or when the viscosity is high, and it becomes more difficult to obtain a uniform coating surface. If a uniform coating surface cannot be obtained, uneven printing will occur.

According to the present invention, a high-quality pigment-coated paper, which cannot be obtained by a conventional coating apparatus used for coating a pigment-coated paper for printing, can be produced at high efficiency by using a curtain coating apparatus. In addition, as a result of further studies, by using a coating liquid containing delamination clay, the printability of the pigment-coated paper is improved, and further, the pigment of delamination clay is It was clarified that the particle size and the proportion of the pigment in the coating solution have a significant influence on the printability of the pigment-coated paper.

Here, the delamination clay is obtained by subjecting naturally occurring kaolin clay (kaolinite) to mechanical force to perform delamination and pulverization, and has a flat plate shape. Is playing. Kaolinite is a dioctahedral 1: 1 layered silicate, and the chemical composition of the 1: 1 layer is ideally Al ₂ Si ₂ O _5. (O
H) ₄ , but it is often the case that some Fe ³⁺ is contained as an octahedral cation by substituting Al. Therefore,
Generally, kaolinite has a plate shape, but when physical force is applied from the outside, delamination occurs between layers, and a flat kaolinite is obtained. Since this pulverizing method is intended for delamination, it is generally called delamination pulverization, and kaolinite obtained by this operation is called delamination clay.

That is, since the delamination clay has a flat shape, if the coating amount is the same, the delamination clay is oriented on the surface of the web and the covering is improved. However, at the present time when the coating operation is accelerated, in a post-metering type coating method such as a blade coating method and an air knife coating method, a high shear rate is applied to the coating layer during measurement, and thus orientation is unlikely to occur. Further, in the roll coating method, the coating surface is disturbed when the coating layer after transfer of the coating liquid and the roll are peeled off, and similarly orientation is unlikely to occur.

On the other hand, in the curtain coating method, the shear rate at the time of measurement is small, and the liquid is not disturbed even at the time of coating. Therefore, the orientation of the pigment progresses smoothly, the effect of covering the pigment is enhanced, the gloss is high, and a coating layer excellent in printability can be obtained.

With respect to the particle size of the pigment, as the proportion of particles having a smaller particle size increases, the tendency of thixotropy increases, making it difficult to form a curtain film, and forming soft agglomerates to cause slits in the coater head. Blockage easily occurs inside the. Further, the effect of the orientation of the particles cannot be expected, so that the gloss decreases.

In the present invention, as a result of intensive studies, a delamination clay containing 80 to 100% by weight of particles having a particle size of 1 μm or more is used to form a curtain film formed from a liquid containing a pigment as a main component. However, it has been found that the coating layer is stable in a wide flow rate range, has an excellent gloss, and can be coated uniformly and without causing coating defects. Here, the particle diameter was measured by a photoprecipitation method.

Further, in the present invention, it has been revealed that by incorporating 3 parts by weight or more of the delamination clay, the gloss of the pigment coated paper is improved and the printability is remarkably improved.

Therefore, 3 parts by weight or more of delamination clay containing 80 to 100% by weight of particles having a particle size of 1 μm or more is blended in the coating liquid, and the delamination clay is applied to the web by using a curtain coating device to obtain gloss. It has been found that an excellent uniform coating layer can be obtained without causing coating defects.

As described above, the present invention is characterized in that the pigment coating layer which comes into contact with the web is coated by the curtain coating method. However, the coating liquid contains 80 to 100% by weight of particles having a particle diameter of 1 μm or more. By containing 3 parts by weight or more of the delamination clay containing the coating solution and applying the coating solution to the coating of the pigment coated paper for printing by using a curtain coating device, no coating defect occurs and the coating operation is performed for a long time. A method for obtaining a pigment-coated paper for printing which is capable of performing a stable coating operation in which uneven coating or the like does not occur even when the coating spreads and has a uniform coating amount and high gloss and smoothness has not been found yet.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic view of a coating apparatus for coating a pigment coated paper for printing showing an embodiment of the present invention. The coating liquid prepared in advance is sent from the coating liquid storage tank 12 to the coater head 1 by the liquid supply pump 13. At this time, since the delivery amount of the coating liquid is proportional to the application amount of the final product, it is necessary to accurately control the delivery amount of the coating liquid to the coater head 1. Therefore, a variable flow type non-pulsating constant flow pump is suitable as the liquid supply pump 13.

The interior of the coater head 1 is composed of a manifold 7 and slits 2, each of which is finished with high precision. The supplied coating liquid is filled in the manifold 7, and the influence of the dynamic pressure due to the liquid feeding of the pump 13 is reduced in the narrow gap that passes when being sent to the slit 2, and the pressure distribution in the width direction is made uniform, Lip 3
Further outflow, a vertical curtain film 4 is formed.

The vertical curtain film 4 having a uniform profile in the width direction comes into contact with the continuously running web 5,
It is applied to the web 5. Here, the edge guides 11a, 1
1b is provided not to exceed the width of the coater head 1 and further to the width of the web 5, and the vertical curtain film is formed to exceed the width of the web 5. The vertical curtain film 4 is formed to exceed the width of the web 5 in order to prevent thick coating of the coating layer on both ends of the vertical curtain film 4. Web 5
The coating liquid that flows down beyond the width of 1 is collected in the liquid receiving tank 10, returned to the coating liquid storage tank 12, and then coated again. Further, even when the coating is interrupted, such as when the web 5 is cut, the coating liquid is collected in the liquid receiving tank 10.

The air flow entrained in the web 5 is shielded at the contact portion between the continuously running web 5 and the vertical curtain film 4 (hereinafter referred to as the "coating portion"), and the air around the curtain is circulated. Web 5 without vertical curtain film 4 being disturbed
A wind shield 9 is provided in order to reach. Further, the web 5 is conveyed in the direction immediately before the coating section by the roll 8 so that the influence of the air accompanying the web 5 on the coating section is minimized.

In order to apply the formed vertical curtain film 4 in a stable state, the coater head 1 is moved from the web 5.
The height to the lower outflow portion is required to some extent, but in the present embodiment, the height can be controlled, and the height suitable for stabilizing the vertical curtain film 4 is 60 to 30.
It is 0 mm, preferably 100 to 250 mm, more preferably 120 to 180 mm.

Needless to say, the present invention is not limited to the above-described embodiments, but can be variously modified. In the above-described embodiment, the width of the formed curtain film is larger than the width of the web 5. This is to prevent an increase in the coating amount at both ends of the coating layer, and such an increase in coating amount is small. If it is not a problem, or if it can be solved by adopting the method disclosed in Japanese Patent Publication No. 49-14130, etc., or other method for preventing increase in coating amount, the vertical curtain film is applied to the web 5 The width may be equal to or slightly smaller than this.

It is also possible to attach a profile adjusting mechanism or a control mechanism to the curtain head. In particular, if a mechanism for adjusting the opening profile is attached to the slit 2 shown in FIG. 1, a more uniform coating amount profile in the width direction can be obtained especially when the coating width becomes large.

The curtain coating device referred to here is as shown in FIG.
As shown in FIG. 2, the narrow slit 2 of the coater head 1
The liquid is allowed to flow out from the liquid to form a curtain-shaped liquid film, and the liquid is applied to the web 5 that continuously runs across the liquid film. FIG. 1 shows the slit 2 of the coater head 1
While the liquid directly flows down to form the curtain film 4 and is applied to the web 5, in FIG. 2, the liquid flowing out from the slit 1 forms a uniform liquid film on the slide surface 6, The curtain film 4 is formed and applied to the web 5. Both of them finally form the curtain film 4 which is a thin falling liquid film similarly, and therefore they are curtain coating devices without distinction, and the present invention includes these.

In the present invention, the coating liquid containing a pigment as a main component is a liquid in which the pigment, the binder and other additives are dissolved or dispersed in water, and the concentration of the pigment, the binder and the other additives is 10%. ~ 70% by weight. The mixing ratio of the pigment and the binder is generally 10 for the pigment.
The amount of the binder is 5 parts by weight or more, preferably 10 to 70 parts by weight, based on 0 parts by weight.

Examples of the pigment for coated paper used in the present invention include kaolin, clay, satin white, titanium oxide, aluminum hydroxide, zinc oxide, barium sulfate, calcium sulfate, silica, activated clay, lake, and plastic pigment. Be done.

As the binder used in the present invention,
Various copolymers of styrene / butadiene, vinyl acetate / acrylic, ethylene / vinyl acetate, butadiene / methylmethacrylate, vinyl acetate / butyl acrylate, polyvinyl alcohol, maleic anhydride copolymer, isobutene / maleic anhydride Acid-based copolymers, synthetic adhesives such as acrylic acid / methyl methacrylate-based copolymers, oxidized starch, etherified starch, esterified starch, enzyme-modified starch and cold water-soluble starch obtained by flash-drying them, casein, A commonly known adhesive such as a natural adhesive such as soybean protein can be used. If necessary, various auxiliaries such as a thickener, a water retention agent, a water resistance agent, a colorant and the like, which are mixed with a usual pigment for coated paper, can be appropriately used.

The coating composition of the present invention thus obtained is
A single-layer or multi-layer coating is applied to both sides or one side of the web. A coating device other than the curtain coating device can be used for coating the lower layer portion in the multi-layer coating, and a wet-on-wet coating method in which the upper layer coating is performed without drying the lower layer coating portion may be performed.

The web used in the present invention includes generally used high-quality paper, medium-quality paper, waste paper, machine-coated paper,
Includes art paper, cast coated paper, synthetic paper, resin coated paper, plastic film, etc.

[0037] In the present invention, the coating amount of the coating solution mainly composed of pigment on a dry weight standards, 1 g / m ² or more, preferably, suitably 3 to 30 g / m ^2.

[0038]

In the present invention, the curtain coating device is set to 1 μm.
By applying the delamination clay containing the particles having the above particle diameter of 80 to 100% by weight to the coating liquid containing a pigment containing 3 parts by weight or more as a main component, stable coating can be performed even in long-time operation, It is possible to obtain a pigment-coated paper for printing which has no coating defects, has a glossy coating layer, is uniform and has high smoothness, and does not cause printing unevenness.

[0039]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention thereto. All parts and% shown below are based on weight.

Example 1 60 g / m ² basis weight (absolutely dry) high-quality paper was coated with a curtain coating device so that the absolutely dry application amount was 8 g / m ² .
An undercoating coating solution having a solid content concentration of 48% of the following formulation was prepared and coated at a coating speed of 1200 m / min to prepare an undercoating base paper.

<Undercoating liquid formulation> -Commercial heavy calcium carbonate (carbital 90): 70 parts-Commercial secondary clay (caobrite): 30 parts-Commercial phosphate esterified starch: 9 parts-Styrene-butadiene latex: 8 Part-Commercial polyacrylic acid-based dispersant: 0.1 part-Sodium hydroxide: 0.1 part

A topcoat coating liquid having a solid content concentration of 55% was prepared by the following formulation. The delamination clay used here is prepared by mixing a commercial product so that particles having a particle size of 1 μm or more have a particle size distribution of 84%. Preparation of a pigment-coated paper for printing by applying a top coating solution at a coating speed of 1200 m / min to the undercoating base paper obtained above with a curtain coating device so that the absolute dry coating amount becomes 8 g / m ^2. I went.

<Composition of Topcoat Liquid> Commercially available heavy calcium carbonate (Carbital 90): 30 parts Commercially available secondary clay (Amazon 88): 36.5 parts Commercially available secondary clay (hydrasperth): 30 parts Lamination clay (mixed): 3.5 parts-Commercial polyacrylic acid-based dispersant: 0.1 part-Commercial phosphate esterified starch: 2 parts-Styrene-butadiene latex: 16 parts

Example 2 A delamination clay having a particle size different from that of Example 1 and having a particle size distribution containing 99% of particles of 1 μm or more was used. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 1.

Example 3 The amount of delamination clay added was different from that of Example 1, and the amount of delamination clay added was increased to 8 parts.
The increase is dealt with by reducing the amount of Amazon 88 added from 36.5 parts to 32 parts. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 1.

Example 4 The amount of delamination clay added was different from that of Example 2, and the amount of delamination clay added was increased to 8 parts.
The increase is dealt with by reducing the amount of Amazon 88 added from 36.5 parts to 32 parts. A pigment coated paper for printing was prepared in the same manner as in Example 2 except for the above.

Example 5 Example 1 except that the pigment composition of the topcoat was as follows:
A pigment coated paper for printing was prepared by the same method as described above. -Commercial ground calcium carbonate (Carbital 90): 10 parts-Commercial secondary clay (Amazon 88): 30 parts-Commercial secondary clay (hydrasperth): 10 parts-Commercial delamination clay (mixed): 50 parts

Comparative Example 1 The amount of delamination clay added was different from that of Example 1, the amount of delamination clay added was reduced to 2.6 parts, and the reduction amount was from 36.5 parts to 37.4 parts of Amazon 88. This is dealt with by increasing the amount added. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 1.

Comparative Example 2 The amount of delamination clay added was different from that of Example 2, the amount of delamination clay added was reduced to 2.6 parts, and the reduction amount was 36.5 parts to 37.4 parts for Amazon 88. This is dealt with by increasing the amount added. A pigment coated paper for printing was prepared in the same manner as in Example 2 except for the above.

Comparative Example 3 A delamination clay having a particle size different from that of Example 1 and having a particle size distribution containing 74% of particles of 1 μm or more was used. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 1.

Comparative Example 4 A delamination clay having a particle size different from that of Example 1 and having a particle size distribution containing 45% of particles of 1 μm or more was used. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 1.

Comparative Example 5 The amount of delamination clay added was different from that of Comparative Example 3, and the amount of delamination clay added was increased to 8 parts.
The increase is dealt with by reducing the amount of Amazon 88 added from 36.5 parts to 32 parts. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Comparative Example 3.

Comparative Example 6 The amount of delamination clay added was different from that of Comparative Example 4, and the amount of delamination clay was increased to 8 parts.
The increase is dealt with by reducing the amount of Amazon 88 added from 36.5 parts to 32 parts. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Comparative Example 4.

Comparative Example 7 The coating device was different from that of Example 3, and an air knife coating device was used instead of the curtain coating device, and the coating speed was 400.
Application was performed at m / min. Otherwise, Example 3
A pigment coated paper for printing was prepared by the same method as described above.

Comparative Example 8 The coating apparatus was different from that of Example 3, and coating was performed using a blade coating apparatus instead of the curtain coating apparatus. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 3.

Comparative Example 9 The coating apparatus was different from that of Example 3, except that a gate roll coating apparatus was used instead of the curtain coating apparatus, and the coating speed was 60.
Coating was performed at 0 m / min. Except for this, the pigment-coated paper for printing was prepared in the same manner as in Example 3.

The coated sample was subjected to calendering and then evaluated.

Evaluation Method 1) White Paper Gloss The glossiness of the sample after calendering was measured using a Murakami gloss meter at an incident angle of 75 ° -reflection angle of 75 °.

2) Printing Gloss After a certain amount of ink (Toyo King Ultra 12 Red) was printed on a sample using a RI-II type printing tester, a Murakami gloss meter was made to enter 60 ° -reflection 60 °. As a result, the glossiness was measured.

3) Smoothness Smoothness was measured by a smoother smoothness tester (model SM-6A, manufactured by Toei Denshi Kogyo Co., Ltd.).

4) Printing unevenness The sample was printed on a Roland offset printing machine under the conditions of excessive water supply of dampening water and appropriate conditions, and allowed to stand overnight at room temperature. The printed area having a halftone dot area ratio of 50% was visually evaluated.
As for the evaluation unit, 5 out of the 5 evaluations is the best, and 5 is judged to have no printing unevenness over the front surface of the sample even if the dampening water is excessively supplied. 4 that causes a small print unevenness
If the amount of dampening water is excessively supplied and uneven printing having a relatively large area is generated, it is determined to be 3, and if dampening water is properly supplied, weak printing unevenness is determined. When the occurrence of the above is determined to be 2, and when the supply of the dampening water is appropriate and the occurrence of clear print unevenness is determined to be 1.

5) Coating defect The coating defect was detected by a defect detection device installed in the coating device, and the defect length was evaluated with respect to the coating length.
Application defects that can be detected with the defect detection device are streaks,
It is a defect having an uncoated portion such as scratches and an excessively coated portion such as stains, and can be detected if the width is 0.3 mm or more. The length of the defect is a length obtained by adding 1 m before and after the defect in consideration of the margin when deleting the defect portion. For example, even when the actual length of the defect is 0.1 m, The length will be 2.1 m.

The evaluation results are shown in Table 1 for the examples and Table 2 for the comparative examples. As is clear from the examples and comparative examples,
By applying a coating solution containing a pigment containing 3 parts or more of delamination clay containing 80 to 100% by weight of particles having a particle size of 1 μm or more as a main component by a curtain coating device, white paper gloss, printing gloss, It is possible to obtain a pigment-coated paper for printing that has high smoothness, does not cause uneven printing, and does not cause coating defects.

[0064]

[Table 1]

[0065]

[Table 2]

[0065]

According to the present invention, the coating liquid has a particle size of 1
The delamination clay containing 80 to 100 wt% of particles of μm or more is contained in an amount of 3 parts by weight or more, and when the coating liquid is applied using a curtain coating device, there are no coating defects and print unevenness. It is possible to obtain a pigment-coated paper for printing having excellent gloss and smoothness.

[Brief description of drawings]

FIG. 1 is a schematic view of a curtain coating apparatus using an extrusion type coater head showing an embodiment of the present invention.

FIG. 2 is a schematic diagram of a curtain coating apparatus using a slide type coater head according to another embodiment of the present invention.

[Explanation of symbols]

 1 Coater Head 2 Slit 3 Lip 4 Curtain Film 5 Web 6 Sliding Surface 7 Manifold 8 Roll 9 Windshield 10 Liquid Receiving Tank 11a, 11b Edge Guide 12 Storage Tank 13 Liquid Supply Pump

Claims (2)

[Claims] 1. A pigment-coated paper for printing, comprising a coating layer containing a pigment as a main component, wherein the coating liquid for the coating layer comprises 3 parts of delamination clay in 100 parts by weight of the total amount of the pigment.
A pigment-coated paper for printing having a coating layer, which is contained in an amount of at least 1 part by weight, 80% to 100% by weight of the clay is particles having a particle diameter of 1 μm or more, and is applied by a curtain coating device. 2. A method for producing a pigment-coated paper for printing, which comprises coating a base material with a coating liquid containing a pigment as a main component, wherein 3 parts by weight of delamination clay is contained in 100 parts by weight of the total amount of the pigment. Characterized in that the coating liquid containing 80% to 100% by weight of the clay and having a particle diameter of 1 μm or more is prepared, and the coating liquid is applied onto the substrate using a curtain coating apparatus. A method for producing a pigment coated paper for printing.