JPH0770973A - Surface finishing method for coated paper - Google Patents

Abstract

(57) [Abstract] [Purpose] A coated paper which is surface-finished by a high temperature calorie heated to 100 ° C or higher, and which efficiently produces coated paper with excellent gloss and smoothness as well as stiffness and rigidity. A surface finishing method is provided. [Structure] After coating the base paper with the coating liquid and drying it, when the paper is passed through a high temperature calender that is a combination of a metal roll and an elastic roll heated to 100 ° C. or higher, the surface roughness R _MAX ( JIS B 0651) 0.5-8.0μ
A metal roll having a surface roughness R _MAX of 4.0 μm or less after being filled with Teflon resin in the surface of the metal roll to m and polishing the surface of the metal roll after processing so that the Teflon resin film does not remain on the apex of the protrusion. A surface finishing method for coated paper using.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface finishing method for coated paper, and in particular, the surface finishing is carried out by a heating high temperature calender of 100 ° C. or more, and the coating is excellent in glossiness and smoothness, and at the same time has a paper stiffness and rigidity. The present invention relates to a surface finishing method for coated paper that efficiently produces paper.

[0002]

2. Description of the Related Art In recent years, with the visualization, colorization, and high quality of printed matter, molded products, decorations, packages, exhibits, etc., paper with high glossiness, high smoothness and high quality of coated paper. There is an increasing demand for improved waist and stiffness. In addition, as the printing technology advances, there is a demand for suitable printability and at the same time a bulky coated paper with a strong paper stiffness.

Various proposals have been made for the process of producing coated paper for printing with high gloss and high smoothness. For example, a multilayer coating method using a blade coater (Japanese Patent Publication No. Sho 21-21252),
High gloss and high smoothing method by specific material and high temperature calender finish (Japanese Patent Publication No. 53-7964, Japanese Patent Publication No. 54-125712, 56-68)
188, 56-96992, 56-107098) and the like have been proposed.

In general, coated paper using paper or paperboard as a base paper is prepared by coating a base paper with a coating solution containing a pigment, an adhesive, or a polymer material as a main component, and using a super calender or various types of calendars. It is manufactured by a surface finishing method that passes high-gloss and high-smoothness by passing it through a render. Also known is a cast coating method or the like in which a coating layer in a plastic state is brought into pressure contact with a heating mirror surface drum to finish.

The cast coating method for performing a special coating surface finish can obtain a high quality coated paper, but has a problem in double-sidedness and productivity.

A surface finishing method using a super calender which is excellent in productivity usually requires a metal roll surface temperature of 60.
Used in multi-stage nips in the range of ~ 70 ° C and linear pressure of 150-500 kg / cm. However, in the case of super calender, in order to impart high gloss and high smoothness, there is no way but to increase the density of coated paper by decreasing the paper passing speed or increasing the linear pressure, The paper thickness becomes thin and the density becomes too high, so that the paper stiffness is lowered and the quality of the coated paper is impaired.

On the other hand, in the case of a heating high temperature calender, the metal roll surface temperature is usually 100 to 300 ° C. and the linear pressure is 100 to 300 ° C.
Used at 1 to 6 nips in the range of 400 kg / cm, the surface of the coating layer is softened by the effect of heat, and a high gloss coated paper can be obtained even with a small number of nip. In addition, since the number of nip is small, it is possible to minimize the density change of the coated paper, and it is possible to obtain a bulky and highly glossy coated paper which was difficult with the conventional supercalender surface finishing method. It is possible.

However, as the roll temperature becomes higher, the above-described quality improving effect can be obtained, but on the other hand, the thermoplastic substance in the coating layer adheres to and deposits on the heated high temperature metal roll surface. The smoothness of the surface is deteriorated and the quality of coated paper cannot be maintained.

As described above, particularly in the surface finishing method for double-sided coated paper, the coated surface has high gloss, high smoothness, and is bulky and excellent in stiffness of the paper, and is highly productive. At present, the proposal for the method is not yet satisfied.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a method for improving the above-mentioned drawbacks in a method for finishing the surface of a coated paper by a heating high temperature calender of 100 ° C. or higher. That is, the inventors of the present invention are a heating high temperature calender surface finishing method for coated papers, and as a result of earnestly researching a method capable of simultaneously contradictory quality characteristics and operability in the conventional method, the surface of the metal roll By specifying the roughness and the release treatment method, the coated paper can be efficiently made to have high gloss and smoothness of the coated surface without causing operational troubles such as roll stains, and at the same time, it is bulky and has high rigidity. The present invention has finally been completed by finding a method for obtaining high productivity.

[0011]

According to the present invention, the surface finish of a coated paper is obtained by coating a base paper with a coating solution and drying it, and then passing it through a high temperature calender in which a metal roll heated to 100 ° C. or higher and an elastic roll are combined. In the method, the surface roughness R _MAX (JIS B 0651) of the original roll for metal roll processing is 0.5 to 8.0.
A metal roll having a surface roughness R _MAX of 4.0 μm or less by filling the concave portion of the surface with Teflon resin to a thickness of μm and polishing the surface of the processed metal roll so as not to leave a Teflon resin film on the apex of the convex portion. Is a surface finishing method for coated paper.

[0012]

The method of the present invention will be described in more detail when it is applied to a method for producing a double-sided high-gloss coated paper as an example. In the method for producing coated paper, an aqueous coating liquid is used as the coating liquid used for forming the coating layer. The aqueous coating liquid is a pigment and an adhesive as in the conventional coating liquid for coated paper. Alternatively, the main component is a polymer material.

Examples of pigments include clay, kaolin,
Aluminum hydroxide, calcium carbonate, titanium dioxide,
One or more ordinary pigments for coated paper such as barium sulfate, zinc oxide, satin white, calcium sulfate, talc, and plastic pigments are appropriately selected and used.

Examples of the adhesive include proteins such as casein, soybean protein, and synthetic protein; conjugated diene polymer latex such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic acid ester and / or Acrylic polymer latex such as polymer or copolymer of methacrylic acid ester, vinyl polymer latex such as ethylene-vinyl acetate copolymer, or these various polymer latexes containing a functional group such as a carboxyl group Alkali-soluble or alkali-insoluble polymer latex modified by body; synthetic resin adhesive such as polyvinyl alcohol, olefin-maleic anhydride resin, melamine resin; starches such as positive starch, oxidized starch; carboxymethyl cellulose, Cellulose derivatives such as hydroxyethyl cellulose One or more conventional coated paper or the like adhesive is appropriately selected and used.

Generally, the adhesive is blended in an amount of 5 to 50 parts by weight, more preferably 10 to 30 parts by weight, based on 100 parts by weight of the pigment, and if necessary in the coating liquid. Various aids such as foaming agents, colorants, release agents, and fluidity improvers are appropriately blended, but as an aid for promoting the solidification of the coating layer, for example, amine, amide, polyacrylamine, zinc, etc. , Aluminum, magnesium, calcium,
A salt of a polyvalent metal such as barium may be added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the pigment.

The coating liquid is a coater device used in the production of general coated paper, for example, a blade coater, an air knife coater, a reverse roll coater, a bar coater, a curtain coater, a die slot coater, a gravure coater, a chanplex coater, a size press. The on-machine or off-machine provided with a coater or the like applies a single layer or multiple layers.

The solid content concentration of the coating liquid at that time is generally 40.
~ 75 wt%, but 45-
A range of 70% is preferable. As the base paper, a paper base or board base base paper having a weight of about 30 to 400 g / m ² used for general printing coated paper is used, but the papermaking method is not particularly limited, and acidic papermaking, alkaline papermaking Any papermaking may be used, and of course, a medium-quality base paper containing high-yield pulp can also be used. Further, a base paper pre-coated with a size press, bill blade or the like can also be used.

The coating amount of the coating liquid on the base paper is generally about 3 to 50 g / m ^{2 on} one side in dry weight, but 3 to 25 g / m ^{2 in} consideration of the quality of blank paper of the coated paper and printability. It is desirable to adjust within a range.

As a method for drying the wet coating layer, conventionally known methods such as steam heating, hot air heating, gas heater heating, electric heater heating, infrared heater heating, high frequency heating, laser heating and electron beam heating are used. Various methods such as the above can be appropriately adopted.

In the surface finishing method, after coating and drying, the surface of the metal roll is passed through a high temperature calender heated to 100 ° C. or higher to finish the surface. Examples of calenders include super calender, gloss calender and soft compact calender. Various types of calendars are used in the form of on-machine or off-machine.

The surface finishing method of the coated paper of the present invention is a metal roll of various calendars as described above, and the surface roughness R _MAX (JIS) of the original roll before being processed into the metal roll.
(Defined by B0651) is in the range of 0.5 to 8.0 μm, more preferably 0.5 to 6.0 μm, the concave portion of the roll surface of the original roll is filled with Teflon resin, and the convex portion of the metal roll surface after processing is obtained. The surface roughness R _MAX is 4.0 μm or less, and more preferably 3. so that the part does not leave a Teflon resin film.
It is characterized by using a metal roll whose surface is polished to 0 μm or less.

Conventionally, as a material for the surface of a metal roll constituting a calender, a chilled steel surface-polished or a chrome-plated roll surface has been generally used. ,
When imparting high smoothness, the surface roughness and releasability of the metal roll affect quality and operability.

When the coating layer passes through a plurality of nips including a combination of a metal roll and an elastic roll, the plasticization of the coating layer gradually progresses due to heat transfer from the metal roll heated to a high temperature of 100 ° C. or higher. At the same time, the adhesion of the coated layer to the surface of the metal roll increases, and it is possible to obtain coated paper with excellent gloss and smoothness even with a smaller number of nips than the conventional super calender. Become.

That is, quality imparting by heating and high temperature calendering with a small nip number largely depends on the adhesion between the coating layer and the surface of the metal roll, and the roughness and releasability of the surface of the metal roll depend on the quality level and its releasability. It is an important factor for maintenance.

Therefore, the surface of the coating layer plasticized by contact with the metal roll heated to a high temperature is likely to be subjected to the roughness of the surface of the metal roll. When trying to obtain, it is important to make the surface roughness of the metal roll as smooth as possible,
The surface roughness R _MAX of the metal roll is 4.0 μm or less, more preferably 3.0 μm or less.

As the material for the metal roll, chilled steel or the one whose surface is chromium-plated is generally used. In the case of heating high temperature calender paper, the surface roughness of the metal roll affects the quality. Is especially large,
It is desirable to improve the heat resistance and pressure resistance of the surface of the metal roll by spraying the surface ceramic of tungsten, titanium oxide, aluminum oxide, chromium oxide or the like.

On the other hand, regarding the releasability, as the temperature of the metal roll increases, the adhesion of the coating layer to the metal roll increases, and at the same time, the coating layer component mainly composed of a binder adheres to the surface of the metal roll. Will also increase. Since roll contamination deteriorates the quality of coated paper, it is necessary to temporarily stop the apparatus and clean the roll. In order to finish the surface of coated paper with a heating high temperature calender, it is necessary to maintain and maintain the releasability for highly efficient production.

Conventionally, for imparting releasability, a release agent such as waxes, fats, fatty acids, soaps, surfactants and silicone resins is blended in the coating material, or a finishing metal is used. It has been proposed to apply the release agent continuously to the roll. However, in these methods, the release agent is gradually deposited on the surface of the finishing metal roll to form an excessive release agent film, so that the gloss of the coated paper is lowered.

Further, conventionally, it has been well known to produce a high-gloss coated paper by mixing a thermoplastic resin and another binder. The addition of such a release agent to the coating material using the thermoplastic resin is indispensable in the step of finishing by pressing with a heating high temperature calender, but in order to maintain the surface strength of the coated paper and improve the releasability. It is conventionally known to mix and use other binders.

However, in any case, in the heating high-temperature calender paper passing over 100 ° C., it is the current situation that sufficient releasability is not maintained when it is attempted to maintain the quality of the coated paper. The present inventors have arrived at the present invention as a result of earnest studies for the purpose of suppressing roll contamination without impairing the quality improvement effect of the heating high temperature calender.

A method of coating the surface of a metal roll with a substance having a low surface energy such as Teflon resin to impart releasability is widely used in various fields. However, when it is applied to the surface of a metal roll for calendering, although excellent releasability is obtained, the Teflon resin coating layer on the surface has a relatively short wear life against abrasion and is easily scratched, and the roll surface roughness decreases. However, there are problems that surface scratches are directly transferred to the coated paper and the quality of the coated paper is impaired, and that the pressure resistance is low and deformation (cold flow) is likely to occur when a load is applied.

Therefore, the inventors of the present invention have specified the surface roughness of the metal roll as described above, and selectively fill the recesses with Teflon resin to release the metal roll without affecting the smoothness of the surface. I tried to give it sex.

On the surface of the metal roll, which is finished so as to look like a mirror surface at first glance, there are innumerable microscopic irregularities such as polishing marks and polishing residues. When observed as, it shows a shape in which mountains and valleys are continuous.

Therefore, the surface of the raw roll for processing the Teflon resin is made uneven to have a surface roughness R _{MAX in} the range of 0.5 to 8.0 μm, and a dispersion of Teflon resin particles of about 0.2 μm is placed in the recess. By coating and filling, and then polishing the surface so that the Teflon resin coating layer is not formed on the convex portions of the surface, the Teflon resin is filled only in the valley portions of the roll surface, that is, the concave portions, and the metal is formed. The roll surface shows a shape in which the tops of the metal parts and the parts filled with Teflon resin are distributed irregularly, the recesses of the valleys are Teflon resin, and the tops of the peaks of the ridges are Teflon resin processed surfaces with virtually zero film thickness. Is obtained.

As described above, unlike the conventional method of coating with the Teflon resin film, since the Teflon resin film layer does not exist near the apex of the convex portion of the roll surface, the Teflon resin is damaged or deformed by cold flow under pressure. The problems such as the above are solved, and the release property of the Teflon resin that is distributed makes it possible to maintain both quality improvement and operability under high temperature calender conditions without causing deterioration of coated paper quality.

The ratio of the Teflon resin to the metal portion on the surface of the metal roll depends on the surface roughness of the original roll, and when the surface roughness R _MAX of the original roll increases, the interval between the peaks increases, The filling amount of the Teflon resin also increases accordingly and the releasability is improved. However, if R _MAX exceeds 8.0 μm and is too coarse, the releasability and quality are maintained as in the case where the roll surface has a Teflon resin coating layer. The balance will be lost. On the contrary, R _MAX is 0.5
If the particle size is too fine to be less than μm and the surface smoothness is too good, the amount of filling in the valley portion is reduced and there is no problem with the quality influence, but the releasability of the core is impaired. Therefore, maintaining quality and the balance of well express releasability, surface roughness R _{MA X} original roll before the metal roll Teflon coating 0.5～8.0Myuemu, more preferably 0.
It is important to be in the range of 5 to 6.0 μm. In addition,
The surface roughness of the processed metal roll is as described above.
It is important to polish as smoothly as possible, and the surface roughness should be at least 4.0 μm or less.

The material of the Teflon resin is a fluororesin type resin, which is typified by polytetrafluoroethylene and has characteristics such as low friction coefficient and heat resistance, which can be filled in the concave portion of the metal roll surface roughness. Any commercially available product may be, for example, Super Coat, trade name manufactured by SP Industries.

The material of the elastic roll used in combination with the metal roll in the calendar is conventionally used in the calendar for coated paper, for example, cotton, fill mat cotton, white cotton, woolen paper,
Although asbestos and the like can also be used, elastic rolls containing these natural fibers as a main material are inferior in high-temperature durability, and the surface roughness is likely to decrease quickly, and therefore, for example, urethane, polyamide, epoxy, isocyanate, silicone, An elastic roll made of vinylidene fluoride, phenol, or another resin in a single layer or multiple layers, or an elastic roll formed by containing 50% or more of synthetic fibers such as nylon, tetron, or aramid (hereinafter collectively referred to as a resin roll. It is preferable to use a resin roll of aramid, epoxy, polyamide or the like, which has particularly high heat resistance. Further, a resin roll containing a release agent is also used.

Regarding the hardness of the elastic roll, considering the durability under high temperature and high pressure and the resistance to surface roughening under paper passing, a roll having a Shore D hardness of 75 ° or more is desirable when measured under high temperature, and a metal roll is preferable. When the surface temperature is as high as 150 ° C. or higher, it is preferable to use an elastic roll having a Shore D hardness of 85 ° or higher.

Various processing conditions for surface finishing the coated paper with a heating high-temperature calender include the target coated paper type, base paper conditions, coating layer properties, coating amount, paper moisture, finishing speed, etc. The higher the surface temperature of the calender roll, the more the plasticization of the coating layer is promoted, but it is preferably 100 to 300 ° C., more preferably 100 to 2 ° C.
It is adjusted within a temperature range of about 50 ° C.

As a heating method for the metal roll, conventionally used methods such as steam and electricity are appropriately used and are not particularly limited. However, the induction heating jacket roll maintains local accuracy and uniformity, It is particularly preferably used because a partial temperature change due to a general heating can be avoided. This metal roll called induction heating jacket roll incorporates an induction coil inside the roll, generates a magnetic flux by applying a voltage, and the roll itself is heated from the inside by induction heat generation. A chamber is provided and water or a special oil is sealed under reduced pressure so that the surface temperature of the roll can be kept uniform.

The pressure condition of the calender roll is linear pressure of 1
The range of 00 to 400 kg / cm is preferable, and the number of pressure nips per calender is usually 1 to 6 in the case of a gloss calender or a soft compact calender, and if necessary, two calenders are used to finish both sides. You may. In the case of a super calendar, 3 to 13
Nip is common. Therefore, in surface finishing,
The coated paper comes into pressure contact with about 2 to 12 metal rolls and elastic rolls.

The water content of the coated paper before entering the nip of the calender is preferably about 3 to 10%, and the finishing speed of the calender is about 100 to 1300 m / min, although it varies greatly depending on the weight of the paper and the type of paper. Is preferred. In addition, for the humidity control and humidification of the coated paper after the surface treatment, a roll water coating device, an electrostatic humidifying device, etc. are installed, or by combining various technologies conventionally known in the coated paper manufacturing field. Of course, it is possible to use.

The coated paper to which the method of the present invention can be applied is not limited to the printing coated paper described as an example above. For example, information-related coated paper, packaging paper, etc. It can also be applied to coated paper, industrial household coated paper, and the like. In addition, of course, it can be applied to various coated sheets using films as a base material, for example, magnetic material coated sheets, photosensitive material coated sheets and the like other than the above.

[0045]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, "part" and "%" in the examples mean "part by weight" and "% by weight", respectively.

The method for evaluating the quality of the coated paper in the examples was as follows. Glossiness: White paper glossiness according to JIS P8142 method,
The gloss value at 75 ° was measured using Murakami Color Research Laboratory (GM3-D). Smoothness: White paper smoothness was measured using a smoother smoothness meter (DSM-01) manufactured by Toei Denshi.

Roll dirt: The ease of dirt on the roll surface is
Metal roll temperature 100 ℃, linear pressure 100Kg / cm 2, speed 10
The stain on the surface of the metal roll after visually passing 10,000 m of the coated paper under the condition of 0 m / min was visually evaluated in three grades. (Good- ○, somewhat inferior-△, inferior -x) Releasability over time: After the coated paper was passed 100,000 m under the same paper-passing conditions as described above, the surface releasability of the metal roll was measured. And clean it under the same paper feed conditions as above,
The stains on the surface after passing 000 m through the paper were visually evaluated in three levels. (Good- ○, slightly inferior- △, inferior-x)

Examples 1 and 2 80 parts of kaolin (trade name; UW-90, manufactured by EMC),
Fine grained heavy calcium carbonate (trade name: Carbital 90,
20 parts of Fuji Kaolin Co., Ltd.) was used as a dispersant to disperse 0.2 parts of sodium polyacrylate in a Corless disperser to prepare a pigment slurry having a solid content of 68%. To this pigment slurry, 2 parts of oxidized starch (solid content), 13 parts of styrene-butadiene copolymer latex (trade name; JSR0696, manufactured by Japan Synthetic Rubber Co., Ltd.) (solid content) were added, and water was further added to obtain a solid content concentration of 60. % Coating solution was prepared. Apply this coating liquid to 7
6 g / m ² of base paper with a dry coating weight of 26 g / m per side
Apply to both sides with a blade coater so that it becomes ² , 120
It was dried with a dryer at ℃ and coated on both sides with a water content of 6%.

Then, as an original roll, the surface roughness R _MAX
Is 0.8 μm (Example 1), 1.5 μm (Example 2), and the surface of a chromium oxide ceramic spray roll (manufactured by Union Carbide) is coated with Teflon resin (trade name;
After supercoating, manufactured by SP Industries Co., Ltd.) was filled with Teflon resin in the concave portions on the surface of the original roll, the surface was polished until the Teflon resin film was not left on the convex portions on the roll surface. The surface roughness R _MAX of the metal roll after this processing was less than the surface roughness R _{MAX of the} original roll in both Examples 1 and 2. Using this metal roll and two soft compact calenders consisting of polyurethane-based elastic rolls with one side and two nip, surface finish is performed under the conditions of surface temperature of 120 ° C, speed of 100 m / min, and linear pressure of 200 kg / cm. A coated paper was obtained, and each coated paper was evaluated according to the above-mentioned evaluation items, and the results are shown in Table 1.

Examples 3 and 4 10 parts of Sachin White (manufactured by Shiraishi Kogyo Co., Ltd.), 50 parts of kaolin (trade name; UW-90, manufactured by EMC), particulate heavy calcium carbonate (trade name: Carbital 90, Fuji Kaolin Co., Ltd.) 40 parts by weight of sodium polyacrylate 0.
1 part was used to disperse in a Corless disperser to obtain a solid content concentration of 65
% Pigment slurry was prepared. To this pigment slurry, 1 part of phosphoric acid-modified starch (solid content), 15 parts of styrene / butadiene copolymer latex (trade name: 0696, manufactured by Japan Synthetic Rubber Co., Ltd.) (solid content) were added, and water was further added to solidify. A coating liquid having a concentration of 60% was prepared. 20 parts of this coating solution kaolin (trade name: HT, manufactured by EMC), heavy calcium carbonate (trade name: Carbital 75, manufactured by Fuji Kaolin) 80
Part, GPC oxidation-modified starch 15 parts, styrene-butadiene copolymer latex (solid content) 10 parts,
76 g / m ² base paper coated with an on-machine gate roll coater so that the dry coating amount is 10 g / m ^{2 on} both sides, so that the dry coating amount is 21 g / m ² per side Was coated on both sides with a blade coater and dried with a dryer at 120 ° C. to coat both sides with a water content of 7.5%.

Subsequently, the surface roughness R _MAX of the original roll is 2.
5 μm (Example 3), 5.0 μm (Example 4) surface is chilled steel surface not subjected to ceramic spraying Teflon coating (trade name; Super Coat, manufactured by SP Industry Co., Ltd.) and recessed on the surface of the original roll After being filled with Teflon resin, the surface was polished until the Teflon resin film was not left on the convex portion of the roll surface. The surface roughness R _MAX of the metal roll after this processing is 1.5 μm (Example 3), 2.5 μm.
m (Example 4). Using this metal roll and two polyurethane-based elastic Rompact calenders, the surface temperature is 150 ° C., the speed is 600 m / min, and the linear pressure is 250.
The surface finish was performed under the condition of kg / cm to obtain a high-gloss coated paper, and each coated paper was evaluated according to the above-mentioned evaluation items, and the results are shown in Table 1.

Comparative Examples 1 and 2 The surface of the chilled steel roll of Example 3 was subjected to Teflon film coating treatment with a thickness of 10 μm, and R _MAX was set to 3 μm (Comparative Example 1) and 4 μm (Comparative Example 2), respectively. A double-sided gloss coated paper was obtained in the same manner as in Example 1 except that a metal roll was used, and the evaluation results are shown in Table 1.

Comparative Examples 3 and 4 In Example 4, in the metal roll having the surface of chilled steel coated with Teflon (trade name: Super Coat, manufactured by SP Industries Co., Ltd.), R _MAX was 8 μm (Comparative Example 3) and 10 μm ( Example 3 except that Comparative Example 4)
Double-sided glossy coated paper was obtained in the same manner as in 1. and the evaluation results are shown in Table 1.

Comparative Examples 5 and 6 The surface roughness R _MAX used in Example 3 was 0.8 μm each.
m (Comparative Example 5), 1.5 μm (Comparative Example 6), except that the surface of the metal roll was coated with oleic acid and then passed through, and then double-sided gloss coated paper was obtained in the same manner as in Example 3, and the evaluation results were shown. It is described in Table 1.

Comparative Example 7 In Example 3, as the original roll, the surface roughness R _MAX 1
A double-sided gloss coated paper was obtained in the same manner as in Example 3 except that 0.0 μm chilled steel was used, and the evaluation results are shown in Table 1. The surface roughness R _MAX of the processed metal roll is 5.
It was 0 μm.

[0056]

[Table 1]

[0057]

As is clear from the results shown in Table 1, the coated papers obtained in each of the examples by the production method of the present invention have less stains on the metal roll of the heating high temperature calender, and have glossiness and smoothness. In the above, it has become possible to produce extremely high quality coated paper extremely efficiently.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuyuki Matsushita 4-3-1, Jokoji Temple, Amagasaki City, Hyogo Prefecture Kanzaki Paper Co., Ltd. Kanzaki Mill

Claims (3)

[Claims] 1. A surface finishing method for a coated paper, which comprises coating a base paper with a coating solution and drying it, and then passing it through a high-temperature calender in which a metal roll heated to 100 ° C. or higher and an elastic roll are combined. Original roll surface roughness R _MAX (JI
SB 0651) to 0.5 to 8.0 μm, and fill the concave portion of the surface with Teflon resin, and polish the surface so that the Teflon resin film is not left on the apex of the convex portion of the metal roll after processing to obtain the surface roughness R. A surface finishing method for coated paper, characterized in that a metal roll having a _MAX of 4.0 μm or less is used. 2. The surface finishing method for coated paper according to claim 1, wherein the original roll for processing the metal roll is a surface ceramic sprayed roll. 3. The surface finishing method for coated paper according to claim 1, wherein the metal roll is heated to a surface temperature of 100 to 250 ° C. by an induction heating jacket roll.