JPH01148898A - Production of coat paper having mirror surface gloss - Google Patents

Abstract

PURPOSE: To obtain a coated paper having mirror surface gloss in a high productivity by applying a coating composition containing a heat-softening organic pigment to a base paper, drying the paper and pressing the coating composition to the paper with a press roll. CONSTITUTION: A coating composition containing a heat-softening organic pigment in an amount of 10-50 wt.% based on total pigment is applied to a base paper and the base paper is dried and the coating composition is pressed to the base paper in dried state by pressing the coated surface of the coating composition with a roll, whose surface is mirror face, heated to the surface temperature of softening point or above of the heat-softening organic pigment. The heat-softening organic pigment includes e.g. a plastic pigment consisting essentially of styrene, an acrylic plastic pigment or a binder pigment having a core/shell structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing coated paper having specular gloss.

Conventional technology] As a conventional method for producing coated paper with specular gloss,
A cast coat method is known. The cast coating method is a wet casting method in which a wet coating layer mainly composed of mineral pigments and adhesive is applied to a chrome drum with a mirror surface by applying pressure, and after drying, it is peeled off to transfer the chrome plating mirror surface. After the wet coating layer is once dried, the coating layer that has become d-shaped by rewetting is pressed onto the surface of a cast drum having a mirror surface, and then peeled off after drying. A gel casting method is known in which the material is pressed against the surface of a drum having the following properties. All of these methods have in common that a coating layer made plastic with water is pressed against the surface of a cast drum having a mirror surface using a press roll, dried and released from the mold to obtain a mirror finish.

On the other hand, finishing methods using a super calender, a gloss calender, a brush, etc. are known as methods for giving coated paper a glossy finish. However, in the case of gloss finishing using a super calender or gloss calender, the coated paper is pressed in a dry state through the roll nip of the calender, and the gloss finish of the coated surface is achieved by contact with the roll surface. When the number of passes between the rolled rolls increases or the pressure applied is increased, the base paper and coating layer are simultaneously affected by the pressure and deform, and the influence of the base paper's formation becomes stronger.
It will give you a glossy finish, but you won't get a mirror finish.

[Problems to be Solved by the Invention] As mentioned above, the casting method has the advantage of providing excellent specular gloss, but since both methods use water as a plasticizer, the coating layer may dry out. Until this is done, the mold cannot be released from the cast drum surface, resulting in a problem in that productivity is kept extremely low.

In order to speed up this drying speed, various methods have been used, such as increasing the temperature of the heating drum surface, minimizing the passage of the wetting liquid, and controlling the location and method of wetting with the wetting liquid. There is.

However, if the temperature of the cast drum surface is made higher than necessary, explosive water evaporation occurs when the wet TII coating layer and the drum surface come into contact, disturbing the coating layer and making it difficult to obtain a sufficient specular gloss. become unable to do so.

Also, if the amount of wetting liquid is reduced more than necessary, air will be trapped when the cast drum surface and the wet coating layer are pressed together, and this part will not come into contact with the cast drum surface, resulting in uneven gloss. However, the current situation is that sufficient effects have not yet been obtained.

Furthermore, in these casting methods, the wet coating layer and the cast drum surface are completely bonded together in the wet state, so when drying, a small portion of the coating layer remains on the cast drum surface, making continuous operation difficult. This accumulates and eventually becomes impossible to operate. Various efforts have been made to solve this problem, such as examining the components of mold release agents and wetting liquids.
It has not yet achieved sufficient effects.

On the other hand, in the operation of a super calender or a gross calender, the coated paper is usually pressurized, leaves the nip between the LC rolls, and is wound onto a reel as it is. For this reason, depending on the thickness of the base paper, the thicker portions are pressed more strongly and the thinner portions are pressed weakly, which basically causes unevenness and uneven gloss. These minute irregularities and uneven gloss do not pose a problem in the case of art paper or coated paper that has a high glossiness but does not have a mirror window. However, when producing coated paper with a specular gloss, these defects become very noticeable, not only making it impossible to obtain a specular gloss, but also significantly lowering the commercial value.

[Means for Solving the Problems] As a result of detailed analysis and consideration of the problems of the above-mentioned casting method, the present inventors have found that the root cause of the low productivity of the casting method is that the coating layer is It was discovered that water was used for plasticization. On the other hand, with super calenders and gloss calenders, which apply coated paper to a glossy finish by passing it through a pressurized nip between rolls in a dry state, specular gloss cannot be obtained due to the instant bumps and uneven gloss as described above. Therefore, as a result of various studies, the present inventors have found that by including a heat-softening organic pigment in the coating composition, when the coated paper is pressed onto a mirror roll, it can be pressed in a dry state, and when the pressing is finished. By contacting the coated paper with a mirror roll even after coating, the coated paper had a mirror gloss close to that of conventional cast coated paper without wetting the coated layer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing coated paper having a specular gloss that increases productivity and provides a specular gloss close to that of cast coated paper.

In the present invention, a coating composition containing a heat-softening organic pigment of 10 to 50 weight ω parts in 100 weight parts of pigment is coated on a base paper, and after drying, the coated surface of the coated paper is coated in a dry state. is pressed onto the surface of a specular roll whose surface temperature is equal to or higher than the softening point of the heat-softening organic pigment using a pressure roll, the coated surface of the coated paper is kept in contact with the surface of the specular roll even after the completion of the press-bonding, and then peeled off. This is a method for producing coated paper having specular gloss.

The first point of the present invention is that by coating a coating composition containing at least 10 weight parts of a heat-softening organic pigment in the 100 weight parts of a pigment, the heat of the heated mirror roll can be applied without using water. It has been found that the coated layer can be sufficiently plasticized by the following methods. Therefore, there is no need to add water to the coated surface to plasticize it as in the cast coating method, and it is sufficient to press the coated paper in a dry state onto a mirror-finished roll.

Furthermore, the second point is that the coated surface of the coated paper is pressed onto the surface of a heated specular roll using a press roll, and even after the press is finished, the paper is held by the mirror roll and brought into sufficient contact, thereby reducing the thickness of the base paper. It was discovered that by removing the cause of the coating layer, which occurs when the paper passes through the nip, without disturbing the coating surface, the mirror roll surface is transferred to the coating surface, and a coated paper with a mirror gloss can be obtained. It is in.

That is, the present invention was completed by combining a pigment with a specific composition (first point) and a specific finishing method (second point).

Materials The first point of the present invention lies in the paint. In the present invention, the paint used to form the coating layer is a composition containing pigments and adhesives as main components, similar to conventional coating compositions for coated paper. However, in order to sufficiently plasticize the coating layer with a heated specular roll, it is necessary to contain at least 10 to 1 part of Sol ff of a heat-softening organic pigment per 100 parts by weight of pigment. The heat-softening organic pigment is not particularly limited as long as it is a heat-softening organic pigment, such as a styrene-based plastic pigment, an acrylic plastic pigment, or a binder pigment with a core/shell structure. . It is also possible to use two or more of these pigments in combination.

The softening point of the heat-softening organic pigment used in the present invention varies greatly depending on the composition of the plastic pigment and binder pigment, but is approximately in the range of 100 to 200°C.

If the amount of heat-softening organic pigment used is less than 10 parts by weight, the coated layer cannot be sufficiently plasticized by the heat of the heated mirror roll, making it impossible to obtain a sufficient mirror finish.

In addition, if the amount of heat-softening organic pigment used exceeds 50 parts by weight, the amount of material softened by the heat of the heated mirror roll will be too large and the coating layer voids will not be able to absorb it, resulting in stains on the mirror roll. occurs.

The heat-softening organic pigment used in the present invention needs to remain in a form that does not completely melt when the coating layer is pressed onto the heated specular roll, and after being released from the press, the heat-softened organic pigment While being hugged and in contact with the surface, the heat-softening organic pigment is melted and acts as a binder, while
It is thought that the coated surface is completely in close contact with the mirror roll, and the coated paper having the mirror gloss of the present invention can be obtained.

In the present invention, it is necessary that the pigment be a heat-softening organic pigment as described above, and latexes that similarly show heat-softening properties as described below are not included. Latexes also have heat-softening properties, but the reason why they do not exhibit the effects of the present invention is still unclear, but heat-softening organic pigments constitute the skeleton of the coating layer as pigments. In contrast, it is thought that latex acts to fix the skeleton. That is, it is considered that the plasticity of the coating layer required in the present invention is not sufficient unless the plasticity of the skeleton itself of the coating layer is obtained.

In the present invention, since the heat-softening organic pigment is used as described above, the coated surface is plasticized by softening and melting of the heat-softening organic pigment in the paint when it is pressed and brought into contact with the heated mirror roll. Unlike the cast coating method, there is no need to add water to the coated surface to plasticize it.

Therefore, the coated paper is pressed against the heated mirror roll in a dry state, and even after the completion of the pressing, the coated paper is kept in close contact with the roll.

The dry condition of the coated paper is preferably 7 to 9% moisture. If it is less than 7%, plasticization of the coated surface will be difficult to occur, and if it exceeds 9%, the surface temperature of the mirror roll will be lowered, resulting in a heated mirror surface. This is not preferable because the transfer effect on the coated surface will be weakened. Additionally, micro-blister formation may occur due to explosive evaporation of water.

Other pigments include carrion, aluminum hydroxide, calcium carbonate, titanium oxide, barium sulfate,
One or more of the usual inorganic pigments for coated paper such as zinc oxide and sachin white are used.

Examples of adhesives include proteins such as casein and soybean protein, starches and their derivatives such as cationized starch and phosphate esterified starch, cellulose derivatives such as carboxymethyl cellulose, natural water-soluble polymers such as sodium alginate, PVA, polyester, etc. Synthetic water-soluble polymeric substances such as acrylamide, sodium polyacrylate and its copolymers, styrene-butadiene copolymers,
Conjugated diene polymer latex such as methyl methacrylate/butadiene copolymer, acrylic polymer latex such as polymer or conjugate of acrylic acid ester and/or methacrylic acid ester, ethylene/vinyl acetate copolymer latex, or various types thereof. One or more types of conventional adhesives for coated paper, such as alkali-soluble or alkali-insoluble polymer latex, which is obtained by functionally modifying a polymer with a monomer containing a functional group such as a carboxyl group, can be used.

The amount of adhesive used is generally 5 to 100 parts by weight of the pigment.
The amount is adjusted to about 50 parts by weight, more preferably about 10 to 20 parts by weight. In addition, the coating composition may contain release agents used in conventional coating paper compositions such as wax, microcrystalline wax, carnauba wax, metal soap, antifoaming agents, coloring agents, A flow modifier and the like are appropriately blended.

Coating The coating composition thus prepared can be coated using a blade coater, air knife coater, roll coater, flage coater, curtain coater, beam coater, bar coater, gravure coater, etc. used in general coated paper manufacturing. The base paper is coated in one layer or in multiple layers by an on-machine or off-machine coater equipped with an apparatus.

As the base paper, a general paper having a weight of about 30 to 4,509/Td used for general printing coated paper or cast coated paper, a paper base paperboard, or a bond base paper is used.

The coating amount of the coating composition on the base paper is generally 10% by dry weight.
~5097rd, but if the coating amount is small, the thickness of the coating layer plasticized by the mirror roll will be small, and the adhesion to the mirror roll will be poor, making it impossible to obtain a sufficient mirror surface. In addition, even if the amount of coating is larger than necessary, the mirror effect will be saturated and there is a possibility that cracks will occur in the coating layer, so the amount of coating should be 15 to 35 g/foot. It is preferable to adjust within a certain range.

In addition, the coating layer contains a heat-softening organic pigment.
In addition to forming a coating composition, it is possible to form a two-layer structure of a coating composition containing no heat-softening organic pigment as an undercoat layer and a coating layer containing a heat-softening organic pigment as an overcoat layer. Good too. In this case, the coating amount of top coat and undercoat is 1 each.
Even with coatings of 09/Td and 89/Fumoto, the same level of gloss and mirror finish as with one-layer coating can be obtained. In the case of a two-layer structure, two coats of a coating composition containing a heat-softening organic pigment are applied (coating amount is 10 g each).
/i), it is possible to obtain a gloss level and mirror finish higher than that of one layer coating (coating amount: 209/TIt).

Furthermore, the following relationship can be considered between the smoothness of the surface of the coating layer and the structure of the coating layer.

In order to obtain specular gloss, it is essential that the coated paper surface has high smoothness. If the smoothness is low, diffuse reflection will occur on the surface, making it impossible to obtain specular gloss. Although it is difficult to define the smoothness strictly, the Peck smoothness is at least 150.
Smoothness of 0 seconds or more is required.

It is possible to sufficiently increase the smoothness by using the finishing method described in the present invention, in which the material is brought into contact with a heated mirror roll for a fixed period of 8 hours after nipping.

However, when coating a base paper with extremely low smoothness or extremely poor texture, undercoating with a pigment that does not contain a heat-softening pigment as shown in the present invention is used to smooth and smooth the base paper. It is also possible to increase the properties and then apply a topcoat with a paint containing a heat-softening organic pigment.

Further, by using a paint containing a heat-softening organic pigment in the undercoat layer, it is possible to sufficiently improve the smoothness. In such a case, if the total coating amount is not at least 10g/Td, the adhesion to the mirror roll will be poor as in the case of 1F1 coating, and a sufficient mirror surface will not be obtained. .

In addition, the coating amount of the top coat layer containing heat-softening pigment is 8g.
/ below, plasticization by heat will not be sufficient and it will be difficult to obtain a mirror surface.

Mirror Finishing The second point of the present invention is the mirror finishing method.

As mentioned above, finishing methods such as super calender, gloss calender, and brush are conventionally known as gloss finishing methods for coated paper. However, in the normal operating method of super calenders and gloss calenders, the paper leaves the nip of the gloss finish roll and is wound onto the reel as is. For this reason, the thicker parts due to the thickness of the base paper are stronger,
Thinner parts are pressed more weakly and are affected by the pressure welding, resulting in uneven gloss and other effects.Furthermore, since there is no operation to correct this, uneven gloss and minute surface irregularities remain, resulting in a mirror finish. I couldn't do it.

In addition, even in the brush treatment, the surface is made with microscopic irregularities by the brush, so it was not possible to finish the coated paper with a mirror surface.

The present inventors believe that in order to obtain mirror gloss, it is essential to use a surface finishing method that negates the effects of the pressure nip, as in the conventional casting method, and therefore, we believe that it is essential to use a surface finishing method that cancels out the effects of the pressure nip, so that even after passing through the nip with the press roll, the heating mirror surface roll By holding the paper for a certain period of time and bringing it into contact with the roll surface, a mirror surface is transferred to the thermoplasticized coating layer, resulting in a coated paper with specular gloss. In this case, it goes without saying that unless the coated layer contains a certain amount or more of a heat-softening organic pigment, the coated layer will not have thermoplastic properties, and therefore mirror transfer will not be possible.

In general, the higher the nip pressure is, the more effectively the heat of the heated mirror surface [l-l] is transmitted to the coated layer, making it easier to obtain a mirror surface. However, if the nip pressure is higher than necessary, depending on the properties of the heat-softening organic pigment used in the coating layer, the coating layer may be pressed too tightly against the heated mirror roll surface, causing a part of the coating layer to become heated. It adheres to the mirror-finished roll surface, roughens the mirror surface, and accumulates roll dirt, which may eventually make operation impossible.

It also has the disadvantage of increasing the density of the paper and reducing the bulk of the paper. For this reason, the nip pressure is 100 to 300K.
It is preferable to adjust within the range of g/CII.

The surface temperature of the heated mirror roll has an appropriate range depending on the softening temperature and melt viscosity of the heat-softening organic pigment used in the coating layer. In general, the higher the surface temperature of the heated mirror roll, the better the heat transfer to the coated layer and the more plasticized the coated layer, which is preferable. However, if the temperature of the heated mirror roll is higher than necessary, part of the coated layer will adhere to the heated mirror roll, disturbing the mirror surface or causing explosive evaporation of the water contained in the paper layer. Problems such as the formation of blisters may occur.

For the above reasons, the surface temperature of the heated mirror roll is 1
It is preferable to adjust the temperature within the range of 50°C to 220°C.

In contrast to normal casting methods, the time the paper is in contact with the heated mirror roll is limited to until the coated layer dries.
The present invention has no such limitation.

Therefore, in the present invention, there is no particular upper limit to the contact time of the coated paper with the heated specular roll in order to obtain specular gloss. However, if the contact time is too long, the heat-softening pigment in the coating layer will melt more than necessary, which will reduce the whiteness of the coating layer, which is not preferable. The approximate contact time to the heated mirror roll of the present invention is 1.5 seconds or less, preferably 0.6 seconds or less. However, if the contact time is too short, the transfer of the mirror surface will not be sufficient, so at least 0.15 seconds or more is required.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is of course not limited to these.

Further, unless otherwise specified, parts and percentages shown in the text are mold mouth parts and weight percentages, respectively.

Example 1 50 parts of kaolin, 10 parts of titanium dioxide, and 065 parts of sodium polyacrylate were dispersed in water using a Coles disperser to prepare a pigment slurry with a solid content of 60%.

In addition, a binder pigment (Asahi Kasei L
-8808) as a solid content, 3 parts of casein dissolved using ammonia as an adhesive, and styrene.
A coating liquid was prepared by adding 13 parts of a copolymer latex containing butadiene as a main component and adjusting the concentration to 45% solids. The coating liquid thus obtained was coated and finished using the apparatus shown in the figure.

That is, the above-mentioned coating liquid was coated on a paperboard base paper 1 having a 31 GSF/m yen area with an air knife coater 2 so that the dry coating amount was 22 g/Td, and the coating liquid was coated with a hot air dryer 3 so that the moisture content was 8%. dried.

Next, the paper is passed through a press nip formed by a rubber-coated press roll 4 and a chrome-plated mirror-finished dielectric heating roll 5, and is heated at a press nip pressure of 20ON9/z to 18
It was pressed onto a mirror finish roll 5 heated to 0°C. The position of the take-off roll 6, which can be freely changed, is adjusted so that the contact time between the mirror-finished roll and the coated surface is 0.6 seconds, and the take-off roll 6 peels off the mirror-finished roll 5 and winds up the finished coated paper. I got a 7.

Example 2.3 Comparative Examples 1 to 3 Coated paper samples were obtained in the same manner as in Example 1 except that the formulation of the coating liquid was changed as shown in the table.

Example 4 60 parts of kaolin and 0.5 parts of sodium polyacrylate were dispersed in water using a Coles disperser to prepare a pigment slurry with a solid content of 60%. To this, 40 parts of polystyrene (Asahi Kasei L-8801) with a particle size of 5500 as a heat-softening organic pigment, 2.0 parts of stearamide as a mold release agent, and 3 casein dissolved in ammonia as an adhesive. 16 parts of copolymer latex containing styrene and butadiene as main components were added to adjust the solid content to 45% to obtain a coating liquid.

The coating liquid thus obtained was applied by hand to a paperboard base of 310 g/rd square meter with a Meyer bar to a dry coating weight of 209/rr, dried in an oven at 110°C for 2 minutes, and then heated at 20°C. Humidity was controlled for 24 hours in an environment with a relative temperature of 65%. Moisture content was 8.9%.

Next, a 3109/ni paperboard was passed through the apparatus shown in the figure, hand-coated paper was pasted before the press nip, and the paper was finished under the finishing conditions shown in Table 1 to obtain a coated paper sample.

Comparative Example 4 A coated paper sample was obtained in the same manner as in Example 4, except that the oven drying conditions were 200° C. for 60 minutes. In addition,
The moisture content after humidity adjustment was 8.7%.

Example 5.6 Comparative Example 5.6 70 parts of kaolin, 010 parts of satin, 0.5 parts of sodium polyacrylate, and 3 parts of casein dissolved in ammonia as a solid content were dispersed in water using a Coles disperser, A pigment slurry with a solids content of 50% was prepared.

In addition, a binder pigment (Asahi Kasei L-88
05) in a solid content of 20 parts, and a copolymer latex containing styrene-butadiene as a main component as an adhesive in a solid content of 14 parts.
The solid content was adjusted to a concentration of 45% to obtain a coating liquid.

Use high-quality paper with a weight of 65 g/d as the base paper, and dry coat it with an air knife coater for 120 minutes using the device shown in the figure.
It was coated to give SF/d and finished under the conditions shown in Table 1 to obtain a coated paper sample.

Example 7.8 Comparative Example 7.8 Undercoat coating liquid 90 parts of kaolin, 10 parts of light calcium carbonate, and 0.6 parts of sodium polyacrylate were dispersed in water using a Coles disperser to form a pigment with a solid content of 60%. A slurry was prepared. To this, 3 parts of phosphate esterified starch as an adhesive as a solid content and 16 parts of a copolymer latex mainly composed of styrene and butadiene were added, and the concentration was adjusted to a solid content of 45% to obtain an undercoat coating liquid. Ta.

Top coating liquid 70 parts of kaolin, 10 parts of light calcium carbonate, and 0.6 parts of sodium polyacrylate were dispersed in water using a Coles disperser to obtain a pigment slurry with a solid content of 60%. To this, 20 parts as a solid content of Panider pigment used in Example 5 as a heat-softening organic pigment, 3 parts as a solid content of phosphoric acid esterified starch as an adhesive, and a copolymer mainly composed of styrene and butadiene. 13 parts of the combined latex was added as a solid content and the concentration was adjusted to 45% solid content to obtain a top coating liquid.

4509/rd
The undercoat coating liquid was applied to the paperboard using an air knife coater to give a dry coating of 18 g/Mi, and the paper was passed from the outlet of the hot air dryer 113 shown in the figure to the vapor roll 8 as shown by the broken line, and the coated paper was wound up. I got a 7.

Further, using the coated paper roll 7 as the base paper 1, dry coated paper ffi
Apply top coat liquid to 10g/Td,
Coated paper samples were obtained by finishing under the conditions shown in Table 1.

Example 9.10 Comparative Example 9.10 80 parts of kaolin, 0.5 parts of sodium polyacrylate]-
A pigment slurry with a solid content of 60% was prepared by dispersing it in water using a less-reducing machine. Example 1 was added to this as a heat-softening pigment.
Added 20 parts as a solid content of the vanider pigment used in , 3 parts as a solid content of casein dissolved in ammonia as an adhesive, and 13 parts as a solid content of copolymer latex mainly composed of styrene and butadiene. minute 45
% concentration was adjusted to obtain a coating liquid. Yonetsubo 2109 /
WL paperboard was coated with a dry coating ff of 120 g/m using the apparatus shown in the figure and finished under the conditions shown in Table 1 to obtain coated paper samples. In addition, in Comparative Example 10, as shown by the dashed line in the figure, only the nip was passed through, and contact with the mirror roll 5 was not performed.

The quality evaluation test results of the obtained coated paper, such as specular gloss, 45° and 20° white paper gloss, and Bekk smoothness, are shown in Table 2.

Quality test method 45°, 20° white paper glossiness Murakami Color Technology Institute! Measured using II GH-30.

A fluorescent light source was projected at a distance of 301 degrees from a fluorescent lamp with a specular gloss of 201J at an angle of 45 degrees, and the clarity of the fluorescent tube image visible on the coated surface was evaluated on the following four levels.

O: The image is clearly visible O: The image is very clear Δ: The image is blurry From Tables 1 and 2, which show the results, the coated paper obtained in the example of the present invention was found to have a higher performance compared to the coated paper obtained in the comparative example outside the range of the implementation conditions of the present invention. It is clear that a coated paper with high gloss and Bekk smoothness and mirror windows can be obtained.

When the heat-softening pigment is contained in a larger amount than necessary (Comparative Example 1), when the surface temperature of the mirror roll is too high under the surface finishing conditions (Comparative Example 5), the nip pressure between the press roll and the mirror roll is When it is too high (Comparative Example 7), stains occur on the mirror roll surface and the mirror surface of the coated paper is disturbed.

Also, the contact time with the mirror roll is too long (Comparative Example 9)
Although a mirrored window appears, the whiteness decreases and is not desirable. (
(margin below) Table 2 OK Susu--Art 45° 20° 2B,
2 4.5 Cast coat OK enamel 62.7 40.0 [Effects of the invention] The coated paper manufacturing method of the present invention has the above-mentioned structure, thereby producing a cast coat that can be obtained by the conventional cast coat method.
We improved the low productivity of cast coating, which requires water to plasticize the coated layer, by using coated paper with a mirror-like gloss similar to that of paper. This is an excellent method that allows for the plasticization of plastics with high productivity and low cost.

[Brief explanation of the drawing]

The figure is a side view for explaining the steps of the method for producing coated paper with specular gloss according to the present invention. 1... Base paper winder, 2... Air knife coater, 3...
...Hot air dryer, 4...Press roll, 5...Specular E-gear dielectric heating [1-ru, 6...Take-off 0-ru,
7... Finish coated paper roll, 8... Paper roll.

Claims (1)

[Claims] After coating the base paper with a coating composition containing 10 to 50 parts by weight of a heat-softening organic pigment in 100 parts by weight of the pigment and drying, the coated surface of the coated paper was heated to a surface temperature above 100% in the dry state. A specular gloss characterized by pressing a heat-softening organic pigment onto the surface of a specular roll having a softening point or higher using a press roll, keeping the coated surface of the coated paper in contact with the specular roll surface even after the completion of the press-bonding, and then peeling it off. A method for producing coated paper having