JP2008302303A - Dryer and method for drying coated film, and apparatus and method for preparing coated object employing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dryer capable of preventing uneven drying in a film forming process that requires accurate control of a film thickness. <P>SOLUTION: The dryer capable of preventing uneven drying of a film in the film forming process that requires accurate control of the film thickness is structured in such a manner that solvent vapor evaporating from a coated film surface is sucked by an air discharge box while fresh air free of the solvent vapor is gently and uniformly supplied onto the coated film surface from an air supply box disposed adjacent to the air discharge box, whereby air in the dryer can quickly be replaced with fresh air without causing an irregularity on the surface of the coated film, thus preventing uneven drying of the coated film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating film drying apparatus and drying method, and a coated product manufacturing apparatus and manufacturing method using them. For example, in the antireflection film, the difference in film thickness is sensitively reflected in the light transmittance, so that a film thickness unevenness with an error of 1% or less is recognized as a product defect. The present invention relates to a coating film drying apparatus and a drying method with high precision as described above, and a coating material manufacturing apparatus and manufacturing method using them.

  There are various techniques for forming a coating film by applying a coating solution with a desired film thickness on the surface of a belt-like substrate that is continuously conveyed, and then drying and curing it in the fields of packaging materials, industrial materials, electronic substrate materials, etc. Development has been done. In particular, in the production of optical functional films such as antireflection films and antiglare films, it is necessary to uniformly form a coating film of several μm or less, and the film thickness change in the drying process after coating is large in product quality. In order to have an influence, technological development for uniform drying is still actively performed.

  A generally well-known drying method is a method of reducing the boundary layer in the air of the solvent component that evaporates and accelerating the drying rate by blowing hot air from the slit nozzle or the pores of the box onto the coating film surface. Is used. In addition, the floating method, in which drying is performed while the substrate is floated by alternately applying hot air to the coating film surface and the substrate back surface, does not require a support roll for the substrate, and heat is efficiently applied to the coating film. Since it is transmitted to the surface, it is used in many fields because the drying efficiency is good and the length of the drying apparatus can be shortened. However, in the above method, since it is necessary to blow air directly onto the coating film surface, there is often a problem that disturbance of the coating film surface due to dry air causes minute film thickness unevenness.

  Further, as a method for preventing the disturbance of the air current on the coating film surface due to the dry air, a method of blocking the disturbance air by covering the entire coating film surface is used. As a cause of the disturbance, there is also a disturbance of the air flow generated when the evaporation solvent gas and the drying air are mixed, and therefore, the coating unevenness often does not disappear.

  Therefore, for example, a method as disclosed in Patent Document 1 is disclosed in order not to disturb the airflow while removing the solvent component that evaporates. In Patent Document 1, hot air is sent in parallel to the coating film formed on the base material in the drying apparatus and in the transport direction of the coating film, and the speed of the hot air that is the laminar flow is transported of the base material. Control is performed so that the relative speed is 0.1 m / second to 5 m / second with respect to the speed. However, with this structure, in order to keep the air flow on the substrate surface to be conveyed in a laminar flow, it is necessary to set the blowing air volume and angle with high accuracy, which is difficult at a practical conveyance speed.

Prior art documents are shown below.
JP 2002-340479 A

  As described above, the present invention provides a coating film drying apparatus and a drying method capable of suppressing the occurrence of drying unevenness in a film forming process that requires precise film thickness control, and a coated product manufacturing apparatus using them. And providing a manufacturing method.

The present invention has been made in view of the above problems, and the invention according to claim 1 is a coating apparatus that applies a coating liquid containing a solvent to a belt-like substrate being transported to form a coating film; In an apparatus for producing a coated product having a drying device for drying while conveying a coating film formed on a material,
The drying apparatus is installed at least on the side on which the coating film of the base material is formed, and a wind regulation member having a plurality of holes, and a bottom plate installed on the side opposite to the side on which the coating film of the base material is formed A coating film transport unit having a right side plate, a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
A square box-shaped drying box that is disposed with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the substrate conveyance direction;
An air supply / exhaust port disposed at a position facing the air conditioning member of each drying box;
Airflow generation selected from either air supply means that forcibly supplies air into the drying box or exhaust means that forcibly exhausts air from the drying box, connected to each supply / exhaust port of each drying box Means,
With
The length of the said dry box of the base material conveyance direction is 10 mm or more and 1000 mm or less, It is a manufacturing apparatus of the coated material characterized by the above-mentioned.

  The invention according to claim 2 is the apparatus for manufacturing a coated product according to claim 1, wherein a gap between the air conditioning member and the coating film is 1 mm or more and 30 mm or less.

  The invention according to claim 3 is the coated product manufacturing apparatus according to claim 1 or 2, wherein the air conditioning member has a hole area ratio of 40% or less.

  The invention according to claim 4 is characterized in that a heating means or a cooling means is installed on the side of the base material where no coating film is provided. It is.

  The invention according to claim 5 is an optical film formed using the manufacturing apparatus according to any one of claims 1 to 4.

The invention according to claim 6 is a coating step in which a coating liquid containing a solvent is applied to a belt-like substrate being transported to form a coating film, and then the coating film formed on the substrate is transported in a drying apparatus. In the manufacturing method of the coated product having a drying step while drying,
The drying device
The air conditioning member that is installed on the side on which the coating film of the base material is formed and has a plurality of holes, the bottom plate that is installed on the side opposite to the side on which the coating film of the base material is formed, and the right side plate, A coating film transport unit having a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
Square box-shaped drying boxes that are arranged with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the conveyance direction of the substrate, An air supply / exhaust port arranged at a position facing the air conditioning member of the drying box, and an air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box, or a drying box An air flow generating means selected from any of exhaust means for forcibly exhausting air from the inside;
Have
An application step of applying a coating liquid containing a solvent to the belt-like substrate being transported to form a coating film;
Next, a transporting process for transporting the coating film from the coating part of the coating process to the carry-in port of the drying device,
Next, a carrying-in process of carrying the coating film into a carrying-in port of the drying device;
Next, a drying step of drying the coating film while conveying the inside of the coating film transport unit of the drying device;
Next, an unloading step of unloading the coating film from the unloading port of the drying device;
Have
The length of the drying box in the substrate transport direction is 10 mm or more and 1000 mm or less.

The invention according to claim 7 is a drying apparatus that applies a coating liquid containing a solvent to a belt-shaped substrate being transported to form a coating film, and dries while transporting the coating film formed on the substrate.
An air conditioning member that is installed at least on the side on which the coating film of the base material is formed and has a plurality of holes, a bottom plate that is installed on the side opposite to the side on which the coating film of the base material is formed, and a right side plate, A coating film transport unit having a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
A square box-shaped drying box that is disposed with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the substrate conveyance direction;
An air supply / exhaust port disposed at a position facing the air conditioning member of each drying box;
Airflow generation selected from either air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box or exhaust means for forcibly exhausting air from the drying box Means,
With
The length of the said drying box of the base material conveyance direction is 10 mm or more and 1000 mm or less, It is a coating film drying apparatus characterized by the above-mentioned.

The invention according to claim 8 is a coating step in which a coating liquid containing a solvent is applied to a belt-like substrate being transported to form a coating film, and then the coating film formed on the substrate is transported in a drying apparatus. In the drying method of the coating film having a drying step while drying,
The drying apparatus is installed on the side of the base material on which the coating film is formed and has a plurality of holes, and a bottom plate on the side opposite to the side of the base material on which the coating film is formed, A coating film transport unit having a right side plate, a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
Square box-shaped drying boxes that are arranged with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the conveyance direction of the substrate, An air supply / exhaust port arranged at a position facing the air conditioning member of the drying box, and an air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box, or a drying box An airflow generating means selected from any of exhaust means for forcibly exhausting air from the inside,
An application step of applying a coating liquid containing a solvent to the belt-like substrate being transported to form a coating film;
Next, a transporting process for transporting the coating film from the coating part of the coating process to the carry-in port of the drying device,
Next, a carrying-in process of carrying the coating film under the first drying box of the drying device;
Next, a drying step of drying the coating film while transporting the inside of the base material transport unit between the bottom plate of the drying device and the air conditioning member;
Next, an unloading step of unloading the coating film from under the last drying box of the drying device,
Have
The length of the drying box in the substrate transport direction is 10 mm or more and 1000 mm or less.

  According to the present invention, the solvent gas evaporated from the coating film surface is sucked in a drying box (hereinafter referred to as an exhaust box) that is exhausting, and at the same time, a drying box (hereinafter referred to as an exhaust box) that is supplying air adjacent thereto. , Called an air supply box), air containing no solvent gas can be gently and uniformly supplied to the coating film surface. Thereby, since air can be replaced quickly without causing disturbance on the coating film surface, it is possible to suppress the occurrence of drying unevenness in a film forming process that requires precise film thickness control.

  In addition, according to the present invention, since the length of the exhaust box and the supply box in the substrate transport direction is 10 mm to 1000 mm, air can be replaced quickly without causing disturbance on the coating film surface. In a film forming process that requires a proper film thickness control, it is possible to suppress the occurrence of uneven drying.

  Further, according to the present invention, since the gap between the air conditioning member and the coating film surface is 1 mm to 30 mm, the air flow becomes a laminar flow, and the air flow is not disturbed. In the required film forming process, drying unevenness does not occur.

  In addition, according to the present invention, the air conditioning member having an aperture ratio of 40% or less can prevent air flow to some extent and make it difficult to generate turbulent flow. Therefore, in a film forming process that requires precise film thickness control, drying is performed. Unevenness does not occur. Here, the aperture ratio of the air conditioning member is a value represented by (area of the hole opening portion / area of the air conditioning member) × 100 (%).

  According to the present invention, by installing the heating means, it is possible to increase the drying speed of the coating film and to perform efficient drying, and at the same time, whitening due to low temperature of the coating film surface due to latent heat at the time of solvent evaporation, etc. It is possible to prevent problems.

  According to the present invention, it is possible to suppress the drying speed of the coating film by installing the cooling means, and it is possible to prevent the flow inside the coating film that easily occurs when the drying speed is too high.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view from the side of a coating film drying apparatus according to the present invention.

  First, the base material 8 wound in a roll is unwound from the unwinding shaft 3 at a constant speed and a constant tension and continuously supplied. The base material 8 is applied with the coating liquid discharged from the coating apparatus 1 on the coating roll 2 arranged to maintain the coating gap. Thereafter, the base material 8 is carried into the drying device 25, and the coating film on the base material 8 is dried and cured, and taken up by a winding device (not shown).

  In the drying apparatus of the present invention, the air conditioning member 5 having smooth and uniform holes is disposed so as to face the surface of the substrate 8 having the coating film. At this time, the gap between the surface of the substrate 8 having the coating film and the air conditioning member 5 is preferably in the range of 1 mm to 30 mm, and more precisely in the range of 1 mm to 20 mm for controlling the drying. desirable. Furthermore, square box-shaped drying boxes 10 to 20 are arranged with the opening portion facing the air conditioning member 5 through the air conditioning member 5. Each drying box has a rectangular box shape, and has a structure having air supply / exhaust ports at positions facing the air conditioning member of the box.

  Either an exhaust means or an air supply means (not shown) is connected to the air supply / exhaust port of each drying box 10-20, and the air inside each drying box is forcibly exhausted or supplied. Each drying box is arranged along the substrate conveyance direction, and the exhaust amount or the air supply amount can be controlled independently by each drying box. Hereinafter, among the drying boxes, the exhaust box is referred to as an exhaust box, and the air supply box is referred to as an air supply box.

  Although FIG. 1 shows a case where 11 drying boxes are arranged, the number of drying boxes is not limited to this. Further, as shown in FIG. 1, it is desirable that the exhaust boxes and the air supply boxes are alternately arranged in order to arrange the exhaust boxes and the air supply boxes.

  The air supplied to the air supply box by the air supply means flows through the air conditioning member 5 into the transport unit 9 where the base material 8 is transported. Further, the solvent component evaporated from the coating film flows into the exhaust box through the air conditioning member 5, and is discharged to the outside by the exhaust means through the exhaust port.

  At this time, the length in the substrate transport direction of one drying box is preferably 10 mm or more and 1000 mm or less from the relationship between the balance between exhaust and air supply, and is in the range of 10 mm or more and 500 mm or less for more precise drying control. It is desirable. In addition, the fluidity of the coating film is high at the initial stage of drying, and even a minute air flow may affect the coating film. Therefore, it is preferable to install an exhaust box immediately after coating in order to prevent the drying air from being applied to the coating film immediately after coating and to prevent the drying air from flowing in the vicinity of the coating part of the coating apparatus 1.

  Further, the transport unit 9 of the drying device 25 of the present invention is surrounded by the air conditioning member 5, the bottom plate 29, the right side plate 27, and the left side plate 28 installed on the side opposite to the side on which the coating film of the base material is formed. It has a structured. This prevents outside air from flowing into the vicinity of the surface of the coating film and makes it less susceptible to the influence. Further, it does not matter whether the coating film is formed on the upper surface side or the lower surface side in the direction of gravity with respect to the substrate 8 to be conveyed.

  A heating or cooling plate 6 may be installed between the guide rolls 6 on the side of the substrate 8 where no coating film is provided, and the drying rate can be controlled by this heat source.

  The air conditioning member 5 used in the present invention is a plate-like member having a plurality of holes, such as a wire mesh or a punching metal, in order to uniformly exhaust the evaporated solvent on the coating film surface, that is, passes through the air conditioning member 5. It has a function to make the flow velocity of the airflow in the vertical direction of the coating film surface (direction from the coating film surface to the wind control member 5) uniform. Considering the air rectifying action, the porosity is preferably 40% or less. The hole diameter is preferably in the range of φ1 mm to φ3 mm that does not affect the coating film, and the hole interval (hereinafter referred to as pitch) is preferably 1.5 to 3 times the hole diameter.

  The drying device 25 in the present invention is installed in the range of 0.2 m or more and 0.8 m or less in terms of the coating film transport distance from the coating unit of the coating device 1. Here, the coating film transport distance refers to the length along the substrate 8 to be transported, not the linear distance between the coating portion where the coating liquid is applied to the surface of the substrate 8 and the carry-in port of the drying box 10. ing. If the coating film transport distance is longer than 0.8 m, the naturally drying region cannot be ignored, and unevenness due to natural drying occurs, which is not preferable. Further, if it is less than 0.2 m, the outside air is excessively blocked at the carry-in port for carrying in the base material 8, which is not preferable. In order to prevent uneven wind, it is preferable that the coating apparatus 1 and the drying apparatus 25 are smoothly connected without any step.

  The drying device 25 according to the present invention can remove the evaporation solvent without adversely affecting the coating film surface and suppress the occurrence of slight drying unevenness. Therefore, the effect is most apparent in the initial stage of drying. Accordingly, the entire length of the drying apparatus is not entirely due to the drying apparatus 25 of the present invention, and it is possible to introduce the drying apparatus 25 of the present invention only in the initial drying stage immediately after application to the substrate 8. In that case, you may introduce | transduce a well-known 2nd drying apparatus after the drying apparatus 25 of this invention.

  As the second drying device, a method of applying a jet of increased temperature to the coating film formed on the substrate from a slit nozzle or punching metal may be introduced, or a quick return nozzle or substrate A system in which hot air is ejected from a nozzle that uses a parallel flow in the transport direction may be used. Moreover, you may provide a heating means not only from one side but from both sides. The use of any commercially available drying apparatus does not interfere with the effects of the present invention.

  Examples of the coating apparatus 1 used in the present invention include, but are not limited to, a die coater, a bar coater, a curtain coater, an extrusion coater, a roll coater, a dip coater, a spin coater, and a gravure coater. It is not something.

  The base material 8 used in the present invention is polyethylene terephthalate, polyethylene-2,6 naphthalate, cellulose diacetate, cellulose triacetate (triacetylcellulose), cellulose acetate propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide. And plastic films such as polyamide, but are not limited thereto. In addition, paper or paper coated or laminated with α-polyolefins having 2 to 10 carbon atoms such as polyethylene, polypropylene, ethylene butene copolymer, and metal foils such as aluminum, copper, and tin are also included. However, it is not limited to these.

  The coating liquid used in the present invention contains a solvent, and any known coating liquid can be used as long as it forms a coating film on a substrate.

  Examples of the solvent used in the present invention include alcohols such as methanol, ethanol, isopropanol, butanol and 2-methoxyethanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl, and esters such as methyl acetate, ethyl acetate and butyl acetate. , Ethers such as diisopropyl ether, glycols such as ethylene glycol, propylene glycol and hexylene glycol, glycol ethers such as ethyl cellosolve, butyl cellosolve, ethyl carbitol and butyl carbitol, aliphatic carbonization such as hexane, heptane and octane Examples include hydrogens, halogenated hydrocarbons, aromatic hydrocarbons such as benzene, toluene, and xylene, N-methylpyrrolidone, dimethylformamide, and the like, or one or a mixture of two or more There may, but is not limited thereto.

  The drying apparatus of the present invention requires high-precision quality, such as optical films, electronic substrates, food packaging materials, medical packaging materials, etc., in the mass production field using a wet coating method that requires a drying process, This ensures stable production quality and contributes to lower costs and higher accuracy.

  With the drying apparatus as shown in FIG. 1, the coating film immediately after the coating liquid was applied to the substrate was dried, and it was confirmed whether or not drying unevenness occurred.

Immediately after coating, an exhaust box was arranged, the width of each drying box in the substrate transport direction was 50 mm, and the total length of the drying apparatus was 2 m. The gap between the base material and the rectifying member was 5 mm, and a rectifying member having a hole diameter of 1 mm, a pitch of 2 mm, and an aperture ratio of about 20% was used. Further, the total flow rate of the exhaust gas and the supply air was set to 5 m ³ / min.

  As the coating solution, a coating solution of 50% toluene solvent and 50% acrylic resin was used, and a polyethylene terephthalate film having a thickness of 100 μm was used as the substrate. As coating conditions, coating was performed by die coating at a coating speed of 30 m / min.

  When coating was performed under the above-mentioned conditions, it was not possible to confirm unevenness that would cause a problem.

<Comparative example>
In the state where the drying apparatus of the present invention is not installed at all, application was performed under the same conditions as in the above example. As a result, it was possible to confirm unevenness in the coating film, and it was not possible to obtain a good product. It was.

It is sectional drawing which shows the outline of the drying apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating device 2 Coating roll 3 Unwinding shaft 5 Air conditioning member 6 Guide roll 7 Heating plate (cooling plate)
8 Substrate 9 Transport unit 10-20 Drying box (exhaust box, air supply box)
25 Drying devices 27 and 28 Right side plate of the transport unit, left side plate 29 of the transport unit Bottom plate

Claims (8)

In an apparatus for producing a coated product, comprising: a coating apparatus that applies a coating liquid containing a solvent to a belt-shaped substrate being transported to form a coating film; and a drying apparatus that dries while transporting the coating film formed on the substrate. ,
The drying apparatus is installed at least on the side on which the coating film of the base material is formed, and a wind regulation member having a plurality of holes, and a bottom plate installed on the side opposite to the side on which the coating film of the base material is formed A coating film transport unit having a right side plate, a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
A square box-shaped drying box that is disposed with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the substrate conveyance direction;
An air supply / exhaust port disposed at a position facing the air conditioning member of each drying box;
Airflow generation selected from either air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box or exhaust means for forcibly exhausting air from the drying box Means,
With
The length of the said dry box of the base material conveyance direction is 10 mm or more and 1000 mm or less, The manufacturing apparatus of the coated material characterized by the above-mentioned.   The apparatus for producing a coated product according to claim 1, wherein a gap between the air conditioning member and the coating film is 1 mm or more and 30 mm or less.   The apparatus for producing a coated product according to claim 1 or 2, wherein the air conditioning member has a hole area ratio of 40% or less.   The apparatus for producing a coated product according to any one of claims 1 to 3, wherein a heating unit or a cooling unit is installed on a side of the base material where no coating film is provided.   An optical film formed using the manufacturing apparatus according to claim 1. A coating step of applying a coating solution containing a solvent to the belt-like substrate being transported to form a coating film; and a drying step of drying the coating film formed on the substrate while being transported in a drying apparatus. In the manufacturing method of the coating material which has,
The drying device
The air conditioning member that is installed on the side on which the coating film of the base material is formed and has a plurality of holes, the bottom plate that is installed on the side opposite to the side on which the coating film of the base material is formed, and the right side plate, A coating film transport unit having a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
Square box-shaped drying boxes that are arranged with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the conveyance direction of the substrate, An air supply / exhaust port arranged at a position facing the air conditioning member of the drying box, and an air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box, or a drying box An air flow generating means selected from any of exhaust means for forcibly exhausting air from the inside;
Have
An application step of applying a coating liquid containing a solvent to the belt-like substrate being transported to form a coating film;
Next, a transporting process for transporting the coating film from the coating part of the coating process to the carry-in port of the drying device,
Next, a carrying-in process of carrying the coating film into a carrying-in port of the drying device;
Next, a drying step of drying the coating film while conveying the inside of the coating film transport unit of the drying device;
Next, an unloading step of unloading the coating film from the unloading port of the drying device;
Have
The length of each said dry box of the base material conveyance direction is 10 mm or more and 1000 mm or less, The manufacturing method of the coated material characterized by the above-mentioned. In a drying apparatus that applies a coating liquid containing a solvent to a belt-shaped substrate being transported to form a coating film, and dries while transporting the coating film formed on the substrate.
An air conditioning member that is installed at least on the side on which the coating film of the base material is formed and has a plurality of holes, a bottom plate that is installed on the side opposite to the side on which the coating film of the base material is formed, and a right side plate, A coating film transport unit having a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
A square box-shaped drying box that is disposed with the opening facing the air conditioning member at a position facing the coating film conveyance unit across the air conditioning member, and one or more installed in the substrate conveyance direction;
An air supply / exhaust port disposed at a position facing the air conditioning member of each drying box;
Airflow generation selected from either air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box or exhaust means for forcibly exhausting air from the drying box Means,
With
The length of the said drying box of the base material conveyance direction is 10 mm or more and 1000 mm or less, The drying apparatus of the coating film characterized by the above-mentioned. A coating step of applying a coating solution containing a solvent to the belt-like substrate being transported to form a coating film; and a drying step of drying the coating film formed on the substrate while being transported in a drying apparatus. In the drying method of the coating film having,
The drying apparatus is installed on the side of the base material on which the coating film is formed and has a plurality of holes, and a bottom plate on the side opposite to the side of the base material on which the coating film is formed, A coating film transport unit having a right side plate, a left side plate, a carry-in port for carrying in the coating film, and a carry-out port for carrying out the coating film;
A square box-shaped drying box that is disposed with the opening facing the air conditioning member at a position facing the coating film conveying unit with the air conditioning member interposed therebetween, and one or more boxes disposed in the conveying direction of the substrate, An air supply / exhaust port arranged at a position facing the air conditioning member of the drying box, and an air supply means connected to each air supply / exhaust port of each drying box to forcibly supply air into the drying box, or a drying box An airflow generating means selected from any of exhaust means for forcibly exhausting air from the inside,
An application step of applying a coating liquid containing a solvent to the belt-like substrate being transported to form a coating film;
Next, a transporting process for transporting the coating film from the coating part of the coating process to the carry-in port of the drying device,
Next, a carrying-in process of carrying the coating film under the first drying box of the drying device;
Next, a drying step of drying the coating film while transporting the inside of the base material transport unit between the bottom plate of the drying device and the air conditioning member;
Next, an unloading step of unloading the coating film from under the last drying box of the drying device,
Have
The drying method of a coating film, wherein a length of each drying box in a substrate conveyance direction is 10 mm or more and 1000 mm or less.