WO2014192685A1

WO2014192685A1 - Drying apparatus and drying method

Info

Publication number: WO2014192685A1
Application number: PCT/JP2014/063814
Authority: WO
Inventors: 蔵方　慎一; 廣瀬　達也
Original assignee: コニカミノルタ株式会社
Priority date: 2013-05-27
Filing date: 2014-05-26
Publication date: 2014-12-04
Also published as: JP2016145649A

Abstract

The present invention improves drying uniformity. A drying apparatus (1A) is provided with: a condenser plate (11) that faces a coating film on a substrate (f1) to be transferred, and dries said coating film by condensing solvent vapor from the coating film; and one or a plurality of heating devices (12) that is disposed at a position facing the condenser plate (11) with the substrate (f1) therebetween, and heats the substrate (f1). The drying apparatus (1A) is heated by the heating device/devices (12) in such a manner that the temperature of the coating film on the substrate (f1) gradually rises. The one or plurality of heating devices (12) is disposed at an inclination to the substrate surface in such a manner that the distance between the heating device/devices (12) and the substrate (f1) gradually decreases in the transfer direction (y) of the substrate (f1).

Description

Drying apparatus and drying method

The present invention relates to a drying apparatus and a drying method.

In an electronic device such as a liquid crystal display element, an organic electroluminescence element, or a solar cell, a gas barrier film that shields permeation of a gas such as water and oxygen is used in order to improve storage stability.
In the gas barrier film, a metal or metal oxide film having low gas permeability is provided as a gas barrier layer on a substrate such as a resin film.

Conventionally, a method of forming a gas barrier layer by depositing a metal or a metal oxide on a substrate by a plasma CVD method (Chemical Vapor Deposition) is also known.
There is also known a method of forming a gas barrier layer by applying a coating solution containing a silicon compound called polysilazane as a main component on a substrate and then converting it to a ceramic such as silicon oxide.

As the film thickness of the gas barrier layer increases, the gas barrier property increases. However, if the coating film containing a silicon compound is simply thickened, cracks are likely to occur after conversion to ceramics.
In order to suppress cracking while obtaining a high gas barrier property, a coating solution containing a silicon compound is applied by a wet process to form a coating film, and a process of performing a modification treatment of irradiating vacuum ultraviolet rays is repeated twice or more, A technique for laminating a plurality of gas barrier layers on a substrate is disclosed (for example, see Patent Document 1).

Since the coating film formed by the wet process contains a large amount of solvent, it is necessary to dry the coating film before the modification treatment. However, it is known that the coating film formed by the wet process is likely to be uneven in drying and it is difficult to make the film thickness uniform.
As a cause of drying unevenness, an organic solvent is generally used for the coating solution, and the viscosity tends to be low. In particular, a coating solution containing a silicon compound tends to have a low viscosity of 100 mPa · s or less. Although it is conceivable to use a thickener, the thickener is not preferable because it can cause deterioration in gas barrier properties.

As a method for drying a coating film applied by a wet process, a condensation drying process is performed in which a condensing plate faces the coating film surface with a narrow gap, and the vapor of the solvent from the coating film is condensed and dried on the condensing surface of the condensing plate. Has been proposed (see, for example, Patent Document 2).
According to this condensation drying process, precise drying can be performed with a simple operation of controlling the distance between the coating film surface and the condensation surface and the temperature of the coating film surface and the condensation surface without using convection heat transfer. it can.

JP 2009-255040 A Special table 2003-524847

The temperature of the coating film surface is adjusted by heating the substrate using a heating device. However, if the substrate is heated suddenly at a strong heat flow rate, temperature unevenness of the coating film surface occurs due to thermal convection, and uniform drying is caused. It becomes difficult.
In particular, when the coating film has a low viscosity and the coating film surface is adjusted to a temperature of 50 ° C. or higher, the evaporation rate of the solvent is not constant due to the temperature unevenness, and the drying unevenness becomes remarkable.
When drying unevenness occurs, a uniform film thickness cannot be obtained, and sufficient gas barrier properties cannot be obtained.

The problem of the present invention is to improve the uniformity of drying.

According to the invention of claim 1,
A condensing plate facing the coating film on the substrate to be transported, condensing the solvent vapor from the coating film and drying;
One or a plurality of heating devices that are disposed at positions facing the condenser plate via the substrate and heat the substrate,
There is provided a drying device characterized in that heating is performed by the heating device so that the temperature of the coating film on the substrate increases stepwise.

According to invention of Claim 2,
The said 1 or several heating apparatus is inclined and arrange | positioned with respect to the board | substrate surface so that the distance with the said board | substrate may shorten in steps in the conveyance direction of the said board | substrate. The described drying apparatus is provided.

According to invention of Claim 3,
The heating devices are arranged such that the surface temperatures of the plurality of heating devices are the same, and the distance from the substrate is gradually reduced in the transport direction of the substrate. The described drying apparatus is provided.

According to invention of Claim 4,
The plurality of heating devices are arranged in the transport direction of the substrate in order from the lowest surface temperature so that the surface temperatures of the plurality of heating devices are different from each other and the distance from the substrate is equal. A drying apparatus according to claim 1 is provided.

According to the invention of claim 5,
The drying apparatus according to any one of claims 1 to 4, wherein the one or more heating apparatuses perform heating by radiant heat.

According to the invention of claim 6,
The drying apparatus according to any one of Claims 1 to 5, wherein the coating film has a viscosity of 100 mPa · s or less.

According to the invention of claim 7,
The drying apparatus according to any one of claims 1 to 6, wherein the coating film contains a silicon compound having a polysilazane skeleton.

According to the invention described in claim 8,
A condensing plate facing the coating film on the substrate to be conveyed is a drying method for condensing and drying the solvent vapor from the coating film,
The substrate is heated so that the temperature of the coating film on the substrate increases stepwise by one or a plurality of heating devices disposed at positions facing the condenser plate via the substrate. A drying method is provided.

According to the present invention, the temperature of the coating film can be increased stepwise, and the occurrence of thermal convection due to a rapid temperature increase can be suppressed. The temperature unevenness of the coating film surface due to thermal convection can be suppressed, the evaporation rate of the solvent can be kept constant even in the temperature rising process, and the drying uniformity can be improved.

It is a front view which shows the structure of the thin film forming apparatus in which the drying apparatus which concerns on 1st Embodiment was used. It is the side view which represented the inside of the drying apparatus of FIG. 1 from the conveyance direction of the board | substrate. It is a figure showing the conveyance distance of the board | substrate from the position where condensation drying was started. It is a front view which shows the structure of the drying apparatus which concerns on 2nd Embodiment. It is a front view which shows the modification of the drying apparatus which concerns on 2nd Embodiment. It is a front view which shows the structure of the drying apparatus which concerns on 3rd Embodiment. It is a front view which shows the structure of the drying apparatus which concerns on 4th Embodiment.

Hereinafter, embodiments of the drying apparatus and the drying method of the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration of a thin film forming apparatus 100 using the drying apparatus 1A according to the first embodiment.
FIG. 2 shows the inside of the drying apparatus 1A from the conveyance direction y of the substrate f1.
As shown in FIGS. 1 and 2, the thin film forming apparatus 100 applies a coating liquid onto the substrate f1 by the coating apparatus 3 to form a coating film f2, and the drying apparatus 1A dries the coating film f2. A thin film is formed on the substrate f1.
The thin film forming apparatus 100 further includes a drying device 4, and the residual solvent can be removed by the drying device 4. Further, the thin film forming apparatus 100 includes the reforming device 5 and can modify the coating film f2.

As shown in FIG. 1, the substrate f 1 is sent to the coating device 3 by the unwinder 21, conveyed by the

rollers

22, 23, and 24, and taken up by the winder 25.

The coating device 3 applies a coating solution containing a solvent on the substrate f1 by a wet process. Examples of the coating method of the coating apparatus 3 include a casting method, an inkjet method, a spray method, a printing method, a slot method using a slit type die coater, an ESD (Electro Spray Deposition) method, and an ESDUS (Evaporative Spray Deposition from Ultra-dilute Solution). ) Law.

As a method of coating on the substrate f1 that is continuously transported, a post-weighing type in which an application liquid is applied in excess of the amount necessary to form a coating film having a required film thickness, and then the excess is removed. A pre-weighing type in which a coating solution is applied in a necessary amount is known. Any coating method can be applied, but the pre-weighing type is preferable from the viewpoints of high accuracy, high speed, thin film, improved coating film quality, suitability for lamination, and the like. Moreover, a closed system is preferable from the viewpoints of suppressing the exposure of the coating liquid, suppressing the change in concentration, maintaining the cleanliness, and preventing the contamination of foreign matters. Therefore, among the above coating methods, a slot method using a slit type die coater and an ink jet method are preferable.

As shown in FIGS. 1 and 2, the drying apparatus 1A includes a condensing plate 11 facing the coating film f2 on the substrate f1. The drying apparatus 1A condenses the vapor of the solvent contained in the coating film f2 by the condensing plate 11, and dries the coating film f2.
The drying device 1 A further includes a heating device 12.

The drying apparatus 1A is preferably installed immediately after the coating apparatus 3 so that it can be dried immediately after the coating liquid is applied. By starting drying immediately after application, it is possible to prevent uneven drying due to the surrounding airflow or natural convection in the drying apparatus 1A. Although it depends on the conveyance speed of the substrate f1, the time from the start of application to the start of drying is preferably within 30 seconds, and more preferably within 10 seconds.
It should be noted that an airflow blocking means such as a blocking plate or a case is provided between the coating device 3 and the drying device 1A, or an airflow rectifying means such as a rectifying plate or a rectifying fan is provided to convection around the coating film f2. It can also be suppressed.

The condensing plate 11 condenses the vapor of the solvent from the coating film f2 on the condensing surface 11a facing the coating film surface f2a.
The material of the condenser plate 11 can be selected as appropriate in consideration of thermal conductivity, weight, processability, processing accuracy, and resistance to solvents. Examples of the material of the condensing plate 11 include metals such as aluminum, copper, iron, and SUS (stainless steel) or alloys thereof, plastic, and wood. Of these, aluminum is preferred because of its excellent workability and thermal conductivity.

The condensing plate 11 may have a plurality of slits formed on the condensing surface 11a. The solvent condensed by the slit can be discharged from the condensing surface 11a, and a decrease in condensation efficiency due to the saturation of the solvent can be suppressed.
The slit may be formed in parallel with the transport direction y, or may be formed in parallel with the width direction x orthogonal to the transport direction y. The solvent condensed on the condensation surface 11a is transported by the capillary force of the slit and is discharged from the condensation surface 11a.
When providing a slit, it is good also as providing the side plate drooping from the side surface of the condensation plate 11, and collect | recovering the solvent discharged | emitted along the slit by the said side plate.

The condensing plate 11 may be subjected to a surface treatment on the condensing surface 11a in order to prevent contamination and efficiently discharge the condensed solvent.
For example, the condensation surface 11a can be subjected to water repellent treatment or hydrophilic treatment.

The heating device 12 heats the coating film f2 through the substrate f1 and promotes evaporation of the solvent.
The heating device 12 is disposed at a position facing the condenser plate 11 via the substrate f1.

The heating device 12 has a planar shape, and is disposed to be inclined with respect to the substrate surface so that the distance from the substrate f1 is shortened stepwise in the transport direction y of the substrate f1. The shorter the distance from the heating device 12, the better the substrate f1 is heated. Therefore, the temperature of the coating film f2 on the substrate f1 rises stepwise in the transport direction y.

When the coating film f2 is heated to a high temperature of 50 ° C. or higher in consideration of the drying efficiency, thermal convection is likely to occur due to the temperature difference between the upstream and downstream in the transport direction y of the substrate f1. Although the solvent is evaporated even while the temperature is rising, if the coating film f2 has a low viscosity, temperature unevenness of the coating film f2 occurs due to convection, and the evaporation rate of the solvent is not constant, so that drying unevenness is likely to occur. .
Prior to condensation drying, the substrate f1 may be transported and heated in a uniform temperature environment as in a heating furnace, and may be condensed and dried after it has been transported for a certain period of time and no thermal convection occurs. However, this method increases the equipment cost. Moreover, when the solvent which is easy to evaporate is used or when the film thickness of the coating film f2 is small, it is also conceivable that a large amount of the solvent evaporates in the heating furnace, resulting in drying unevenness.
However, by increasing the temperature of the coating film f2 stepwise by the heating device 12 as described above, generation of thermal convection can be suppressed. Temperature unevenness of the coating film f2 due to thermal convection can be suppressed, the evaporation rate of the solvent can be made constant, and uniform drying is possible.

Examples of the heating method of the heating device 12 include a heating method using hot air, infrared rays, ultraviolet rays, microwaves, electric resistance, and the like. Among these, from the viewpoint of suppressing drying unevenness due to convection and improving the uniformity of drying, it is preferable to perform heating by radiant heat such as infrared rays. For example, a panel-shaped infrared heater can be used as the heating device 12.

FIG. 1 shows an example in which one heating device 12 is tilted, but a plurality of heating devices can be connected and tilted according to the length of the condensing plate 11 in the transport direction y.

The temperature increase rate of the coating film f2 can be adjusted by changing the inclination angle of the heating device 12, the surface temperature of the heating device 12, and the like.
As shown in FIG. 3, the temperature rise rate of the coating film f2 is at least within a range of 0 to 30 mm when the position of the substrate f1 where condensation drying is started is 0 mm in the transport direction y of the substrate f1. It is preferable to adjust so that the width of the increase is within 40 ° C. in units of 10 mm. Within this range, thermal convection due to the temperature difference of the coating film f2 can be suppressed.

Even at a position after 30 mm after the condensation drying of the substrate f1 is started, the temperature of the coating film f2 may continue to be increased by the inclined heating device 12, but there is also heat radiation from the substrate f1, and it converges to a certain temperature. To go. The surface temperature of the heating device 12, the distance between the heating device 12 and the substrate f1, and the like may be adjusted so that this constant temperature matches the target temperature.
When a plurality of heating devices 12 are used, when the position of the substrate f1 is within a range of 0 to 30 mm, one heating device 12 is inclined so that the temperature of the coating film f2 is increased stepwise to the target temperature. In order to maintain the target temperature after 30 mm, the other heating device 12 can be arranged in parallel so as to face the substrate f1.

In addition, the drying device 1 can also include a preheating device such as a heat roller upstream of the heating device 12 in the transport direction y. With the preheating device, the coating film f2 can be preheated so that the temperature rises more slowly.

The drying speed of the drying apparatus 1A can be controlled by adjusting the temperature Tc of the condensing surface 11a and the temperature Th (Th> Tc) of the coating film surface f2a.
The drying speed increases as the difference in the vapor pressure of the solvent at each temperature Tc and Th increases.

As a method for controlling the temperature Tc of the condensing surface 11a, heating or cooling of the condensing plate 11 by blowing or liquid feeding can be mentioned. The temperature Tc of the condensing surface 11a can be set to room temperature without particularly controlling, and the temperature Th of the coating film surface f2a can be controlled to a temperature sufficiently higher than the room temperature.
The temperature Th of the coating film surface f2a can be adjusted by heating the heating device 12 as described above. If necessary, a cooling device can be used together with the heating device 12 to control the temperature Th of the coating film surface f2a.

The temperature Tc of the condensing surface 11a may be higher or lower than room temperature as long as it is lower than the temperature Th of the coating film surface f2a, but is preferably in the range of 5 to 30 ° C, and in the range of 10 to 20 ° C. It is more preferable that
By controlling the temperature Tc within the above range, an increase in cost required for heating can be suppressed. Further, it is easy to uniformly control the temperature of the entire condensing surface 11a, and it is easy to suppress drying unevenness due to temperature unevenness, and consequently film thickness unevenness of the coating film f2. From the same viewpoint, the temperature unevenness in the condensing surface 11a is preferably within 2 ° C.

In order to prevent substances other than the solvent such as moisture in the atmosphere from condensing on the condensation surface 11a, it is preferable to lower the dew point of the atmosphere or reduce the pressure between the condensation surface 11a and the coating film surface f2a.
Further, in order to prevent the solvent from condensing in a member of the drying apparatus 1A other than the condensing plate 11, such as a housing, it is preferable to adjust the temperature of the member other than the condensing plate 11 to be equal to or higher than the temperature Tc of the condensing surface 11a. .

The temperature Th of the coating film surface f2a may be higher or lower than the room temperature as long as it is higher than the temperature Tc of the condensing surface 11a, but is preferably in the range of 30 to 100 ° C, preferably in the range of 30 to 70 ° C. It is more preferable that
By setting the temperature Th to 30 ° C. or higher, moisture in the atmosphere other than the solvent is condensed and it is easy to suppress a decrease in drying efficiency. By setting the temperature to 100 ° C. or lower, it is easy to suppress an increase in cost due to a high temperature, conveyance failure due to the modification of the substrate f1, and the like. In addition, it is easy to uniformly control the temperature of the entire substrate f1, and it is easy to suppress drying unevenness due to temperature unevenness, and consequently film thickness unevenness of the coating film f2. From the same viewpoint, the temperature unevenness in the coating film surface f2a is preferably within 2 ° C.

The drying speed of the drying apparatus 1A can also be controlled by adjusting the distance d between the condensation surface 11a and the coating film surface f2a.
The smaller the distance d is, the more easily the solvent is condensed and the drying speed is increased, but it is preferably in the range of 0.1 to 10.0 mm, more preferably in the range of 0.1 to 4.0 mm.
By setting the distance d to 0.1 mm or more, it is easy to avoid contact between the coating film f2 and the condensing plate 11 due to flapping of the substrate f1, and it is possible to reduce the cost associated with high accuracy of the arrangement of the condensing plate 11. Moreover, it is easy to avoid adhesion of the condensed solvent to the coating film f2, and drying unevenness due to adhesion can be suppressed. By setting the distance d within 10.0 mm, it is possible to reduce the influence of surrounding convection and prevent drying unevenness, increase the drying speed, and improve productivity.

The distance d between the condensation surface 11a and the coating film surface f2a is preferably maintained at a constant value.
When the distance d is a constant value, the drying speed in the coating film surface f2a can be made constant, and the uniformity of drying can be improved.

The drying device 4 is a drying device for post-processing provided for removing the residual solvent.
The drying method of the drying device 4 may be the same condensation drying as the drying device 1A, or may be another drying method. Other drying methods include drying using hot air, infrared rays, microwaves, ultrasonic waves, etc., vacuum drying, supercritical drying, moisture absorption drying, cooling drying, and the like.

According to the thin film forming apparatus 100, a coating film containing a silicon compound having a polysilazane skeleton can be formed as a gas barrier layer of a gas barrier film, and the coating film can be uniformly dried.
The gas barrier film is a film having a gas barrier layer exhibiting low oxygen permeability and water vapor permeability, and imparts excellent storage stability to an electronic device using the gas barrier film.
The gas barrier performance required for the gas barrier layer varies depending on the electronic device in which the gas barrier film is used. In general, the gas barrier layer has a water vapor permeability (temperature 60 ± 0.5 ° C., relative humidity 90 ± 2%) measured in accordance with JIS K7129: 2008 of 3 × 10 ⁻³ g / m ² · 24 h or less. Yes, when the oxygen permeability measured according to JIS K7126: 2006 is 1 × 10 ⁻³ g / m ² · 24 h · atm or less, it can be preferably used for an electronic device.

For a silicon compound having a polysilazane skeleton, an organic solvent is used as a solvent, and therefore, the viscosity of the coating film tends to be as low as 100 mPa · s or less. When such a low-viscosity coating film is dried by convection heat transfer, the coating solution flows greatly, the evaporation rate of the solvent is not constant, and drying unevenness is likely to occur.
However, since the drying apparatus 1A does not use convective heat transfer, there is almost no unevenness in the flow of the coating liquid and the evaporation rate of the solvent, and uniform drying even when the coating film f2 has a low viscosity of 100 mPa · s or less. Since it can be realized, it is particularly effective for forming the gas barrier layer described above.

In addition, when the temperature Th of the coating film surface f2a is adjusted to a high temperature of 50 ° C. or more in consideration of drying efficiency, the coating film is heated due to a temperature difference between the upstream and downstream in the transport direction y when heated rapidly with a strong heat flux. Thermal convection is likely to occur on the surface f2a. Even in the process of increasing to the temperature Th, the solvent is evaporated, and if the coating film f2 has a low viscosity, temperature unevenness occurs on the coating film surface f2a due to thermal convection, and the evaporation rate of the solvent is not constant. It tends to happen.
However, since the drying apparatus 1A raises the temperature of the coating film f2 step by step, thermal convection hardly occurs and temperature unevenness in the temperature rising process can be suppressed. Thus, the evaporation rate of the solvent becomes constant even during the temperature rise process, and uniform drying is possible, which is particularly effective for forming a gas barrier layer having a low viscosity coating film.

Hereinafter, a procedure for forming a thin film will be described by taking as an example a case where a coating film containing a silicon compound having a polysilazane skeleton is formed and the coating film is dried to form a gas barrier layer.

First, the gas barrier film substrate f 1 is set in the thin film forming apparatus 100.
As the substrate f1 of the gas barrier film, a colorless and transparent resin film is preferably used.
Examples of the resin film material include polyester, methacrylic acid, methacrylic acid-maleic acid copolymer, polystyrene, fluorinated resin, polyimide, fluorinated polyimide, polyamide, polyamideimide, polyetherimide, cellulose acylate, polyurethane, and polyether. Examples include ether ketone, polycarbonate, alicyclic polyolefin, polyarylate, polyether sulfone, polysulfone, cycloolefin copolymer, fluorene ring-modified polycarbonate, alicyclic ring-modified polycarbonate, fluorene ring-modified polyester, and acryloyl compound.

The thickness of the substrate f1 used for the gas barrier film can be appropriately selected depending on the application. In general, the thickness of the substrate f1 is in the range of 1 to 800 μm, preferably in the range of 10 to 200 μm. From the viewpoint of reducing the size and weight of the electronic device, it is more preferably in the range of 10 to 50 μm.

Substrate f1 can be produced by melting and extruding a resin composition as a raw material using an extruder having an annular die or a T die and quenching, and is substantially unstretched with no resin orientation. A substrate f1 is obtained.
This unstretched substrate f1 is stretched by uniaxial stretching, tenter sequential biaxial stretching, tenter simultaneous biaxial stretching or tubular simultaneous biaxial stretching in the transport direction and / or width direction of the substrate f1. A substrate f1 can also be obtained. The width direction refers to a direction orthogonal to the transport direction on the substrate f1. The draw ratio is preferably in the range of 2 to 10 times in the transport direction and the width direction.

The surface of the substrate f1 on which the gas barrier layer is formed may be subjected to surface treatment such as excimer treatment, corona discharge treatment, flame treatment, oxidation treatment, or plasma treatment in order to improve adhesion with the laminated gas barrier layer. Good.

The substrate f1 may be provided with a primer layer in order to flatten the surface of the substrate f1 and improve the adhesion with the gas barrier layer.
The primer layer preferably contains a curable resin such as an active energy ray curable resin or a thermoplastic resin.

As a specific example of the active energy ray curable material, OPSTAR (registered trademark) series which is a UV curable organic / inorganic hybrid hard coat agent manufactured by JSR Corporation can be used. The OPSTAR series is a compound obtained by bonding an organic compound having a polymerizable unsaturated group to silica fine particles.

Specific examples of the thermosetting material include thermosetting urethane resin composed of acrylic polyol and isocyanate prepolymer, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicon resin, polyamidoamine-epichlorohydrin resin, and the like. Can be mentioned. Commercially available thermosetting materials include SP COAT heat-resistant clear paint manufactured by Ceramic Coat, Nanohybrid silicone manufactured by Adeka, Unidic (registered trademark) V-8000 series manufactured by DIC, EPICLON (registered trademark) EXA -4710 (ultra high heat resistant epoxy resin), X-12-2400 (silicon resin) manufactured by Shin-Etsu Chemical Co., Ltd., SSG coat (inorganic or organic nanocomposite material) manufactured by Nitto Boseki Co., Ltd., and the like.

Solvents used in the coating solution containing the curable material include alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, ethylene glycol and propylene glycol, terpenes such as α- or β-terpineol, and acetone. , Ketones such as methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, diethyl ketone, 2-heptanone, 4-heptanone, aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene, cellosolve, methyl cellosolve, ethyl cellosolve , Carbitol, methyl carbitol, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether Ter, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, glycol ethers such as triethylene glycol monoethyl ether, ethyl acetate, butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol Acetates such as acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 2-methoxyethyl acetate, cyclohexyl acetate, 2-ethoxyethyl acetate, 3-methoxybutyl acetate, diethylene glycol dialkyl ether, Dipropylene glycol dialkyl ether, 3-etho Shipuropion ethyl, methyl benzoate, N, N- dimethylacetamide, N, may be mentioned N- dimethylformamide.

The thickness of the primer layer is not particularly limited, but is preferably in the range of 0.1 to 10.0 μm.

In order to prevent the additive in the substrate f1 from bleeding out (deposition), the substrate f1 may have a bleedout preventing layer formed on the surface opposite to the surface on which the gas barrier layer of the substrate f1 is laminated. .
Since the primer layer described above basically has a function of preventing bleed out, a bleed out preventing layer can be formed in the same manner as the primer layer.

Next, the thin film forming apparatus 100 starts transporting the substrate f1, and the coating apparatus 3 applies the coating liquid for the gas barrier layer onto the substrate f1 to form the coating film f2.

The coating solution for the gas barrier layer can be prepared by dissolving or dispersing a silicon compound having a polysilazane skeleton in a solvent.
The polysilazane skeleton is a basic skeleton of a polymer containing a Si—N bond, and is a precursor of ceramics such as silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), or silicon oxynitride (SiO _x N _y ). is there.
Examples of the silicon compound having a polysilazane skeleton include a silicon compound having a structure represented by the following general formula (1). The silicon compound is generally called polysilazane.

In the general formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group, an aryl group, a vinyl group or a (trialkoxysilyl) alkyl group. The alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group may further have a substituent.

Examples of the alkyl group for R ¹ , R ² and R ³ include straight, branched or cyclic alkyl groups having 1 to 8 carbon atoms. More specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n -Hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like.

Examples of the aryl group for R ¹ , R ² and R ³ include aryl groups having 6 to 30 carbon atoms. More specifically, a non-condensed hydrocarbon group such as a phenyl group, a biphenyl group, a terphenyl group; a pentarenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, a fluorenyl group, an acenaphthylenyl group, a preadenyl group A condensed polycyclic hydrocarbon group such as acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceantrirenyl group, triphenylenyl group, pyrenyl group, chrysenyl group, naphthacenyl group, etc. Can be mentioned.

Examples of the (trialkoxysilyl) alkyl group of R ¹ , R ² and R ³ include an alkyl group having 1 to 8 carbon atoms having a silyl group substituted with an alkoxy group having 1 to 8 carbon atoms. More specific examples include 3- (triethoxysilyl) propyl group and 3- (trimethoxysilyl) propyl group.

In some cases, examples of the substituent present in the alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group include an alkyl group, a halogen atom, a hydroxy group (—OH), a mercapto group (—SH), a cyano group. Groups (—CN), sulfo groups (—SO ₃ H), carboxy groups (—COOH), nitro groups (—NO ₂ ) and the like.
The substituent which the alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group may have is the same as the substituted alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group. Absent. For example, when R ¹ to R ³ are alkyl groups, they are not further substituted with an alkyl group.

Preferred R ¹ , R ² and R ³ are hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, phenyl group, vinyl group, 3- (triethoxysilyl) A propyl group or a 3- (trimethoxysilylpropyl) group.

In the general formula (1), n is an integer of 1 or more.
n is preferably determined so that the number average molecular weight Mn of the silicon compound having the structure represented by the general formula (1) is in the range of 150 to 150,000 g / mol.

Among the silicon compounds having the structure represented by the general formula (1), perhydropolysilazane in which all of R ¹ , R ² and R ³ are hydrogen atoms, the resulting gas barrier layer exhibits high density, Particularly preferred.
Perhydropolysilazane is presumed to have a structure including a linear structure and a ring structure centered on a 6-membered ring and an 8-membered ring. Perhydropolysilazane has a number average molecular weight Mn measured in terms of polystyrene by gel permeation chromatography of about 600 to 2000, and is a liquid or solid substance.

Perhydropolysilazane is commercially available as a solution dissolved in an organic solvent, and the commercially available product can be used as it is as a coating solution for the gas barrier layer.
Commercially available products that can be used as the coating solution include AQUAMICA (registered trademark) series NN120-10, NN120-20, NAX120-20, NN110, NN310, NN320, NL110A, NL120A, NL120-20 manufactured by AZ Electronic Materials. NL150A, NP110, NP140, SP140 and the like.

Organopolysilazane, in which at least one of R ¹ , R ² and R ³ is a hydrogen atom and at least one is an organic group such as an alkyl group, also has good adhesion to the substrate f1 and is a ceramicized gas barrier layer Even when the toughness is imparted to the gas barrier layer to increase the thickness of the gas barrier layer, the generation of cracks can be suppressed, which is preferable.
Perhydropolysilazane or organopolysilazane may be selected depending on the application, and both may be used in combination.

As another example of the silicon compound that can be used for the gas barrier layer, a silicon alkoxide-added polysilazane obtained by reacting a silicon alkoxide with a silicon compound having a structure represented by the above general formula (1) (Japanese Patent Laid-Open No. 5-238827) Glycidol-added polysilazane obtained by reacting glycidol (see JP-A-6-122852), alcohol-added polysilazane obtained by reacting alcohol (see JP-A-6-240208), metal carboxylate A metal carboxylate-added polysilazane obtained by reacting with a metal (see JP-A-6-299118), and an acetylacetonate complex-added polysilazane obtained by reacting a metal-containing acetylacetonate complex (JP-A-6-306329) Add metal fine particles) Resulting Te metal particles added polysilazane (see JP-A-7-196986) and the like. These are examples of silicon compounds that ceramize at low temperatures.

Since the silicon compound having a polysilazane skeleton reacts with a reactive group such as a hydroxy group or an amino group and is easily hydrolyzed, the solvent used for the coating solution is an organic solvent inert to the silicon compound. Is preferred.
Specifically, aprotic solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons and halogen hydrocarbons; esters such as ethyl acetate and butyl acetate; ketones such as acetone and methyl ethyl ketone; Mention may be made of ethers such as butyl ether, dioxane, tetrahydrofuran, mono- or polyalkylene glycol dialkyl ethers (diglymes).
A solvent can be selected according to the solubility of a silicon compound, the evaporation rate of a solvent, etc., and may use 1 type (s) or 2 or more types.

The silicon compound content in the coating solution varies depending on the film thickness of the gas barrier layer and the pot life of the coating solution, but is preferably in the range of 0.2 to 80.0% by weight, more preferably 1 to 50% by weight. %, Particularly preferably in the range of 5 to 35% by weight.

The coating solution may contain a catalyst in order to promote silica conversion during the modification treatment.
Usable catalysts include N, N-diethylethanolamine, N, N-dimethylethanolamine, triethanolamine, triethylamine, 3-morpholinopropylamine, N, N, N ′, N′-tetramethyl-1,3 -Amine catalysts such as diaminopropane, N, N, N ', N'-tetramethyl-1,6-diaminohexane, Pt compounds such as Pt acetylacetonate, Pd compounds such as propionic acid Pd, Rh acetylacetonate, etc. And metal catalysts and N-heterocyclic compounds. Of these, a basic catalyst is preferable, and an amine catalyst is preferable.
The content of the catalyst in the coating solution is preferably in the range of 0.1 to 10.0 mol%, more preferably in the range of 0.5 to 7.0 mol% with respect to the content of the silicon compound. Is within. By setting the content of the catalyst within the above range, it is possible to avoid excessive silanol formation, film density reduction, film defect increase, and the like due to rapid progress of the reaction.

The film thickness at the time of application | coating of the coating film f2 can be determined according to the film thickness calculated | required after drying.
As the film thickness at the time of application increases, the coating liquid easily flows and uneven drying tends to occur. Therefore, the usefulness of the drying apparatus 1A capable of uniform drying is great.

The viscosity of the coating film f2 can be appropriately selected depending on the gas barrier performance required for the gas barrier layer and the solubility or decomposability of the silicon compound.
For a silicon compound having a polysilazane skeleton, an organic solvent is used as described above, so that the viscosity of the coating solution is as low as 100 mPa · s or less. In the coating film f2, since the coating liquid easily flows and uneven drying tends to occur, the usefulness of the drying apparatus 1A capable of uniform drying is great.
The specific viscosity of the coating film is preferably in the range of 0.3 to 10.0 mPa · s from the viewpoint of increasing the coating speed and improving the coating property, and 1.0 to 10.0 mPa · s. More preferably within the range of s.

Next, the drying apparatus 1A condenses and dries the coating film f2 of the gas barrier layer.
The drying apparatus 1 A heats the substrate f 1 being transported by the heating apparatus 12. When the solvent in the coating film f2 is evaporated by heating the substrate f1, the vapor is condensed by the condensing plate 11 facing the coating film f2, and the coating film f2 is dried.

The thickness of the gas barrier layer after drying is preferably in the range of 1 nm to 100 μm, more preferably in the range of about 10 nm to 10 μm, still more preferably in the range of 50 nm to 1 μm, particularly preferably. It is in the range of 100 to 500 nm.
If the film thickness is 1 nm or more, sufficient gas barrier performance can be obtained, and if it is 100 μm or less, stable coating properties and high light transmittance are obtained.

After the coating film f2 is dried, the reforming apparatus 5 modifies the coating film f2 on the substrate f1, thereby obtaining a gas barrier layer.
The modification treatment is a treatment in which part or all of the silicon compound contained in the coating film f2 of the gas barrier layer is converted into silica and converted into ceramics.
Examples of the modification treatment include a method of irradiating ultraviolet light having a wavelength of 400 nm or less, a method of irradiating vacuum ultraviolet light (VUV; Vacuum Ultra Violet) having a wavelength of less than 180 nm, and the like.

The example of forming the gas barrier layer of the gas barrier film has been described above, but other layers such as a primer layer and a bleed-out layer can also be formed by the thin film forming apparatus 100.
Besides the gas barrier film, the coating device 3 is used to form a coating film f2 of an organic layer such as an organic EL element, a solar cell, a transistor, a memory, a sensor, etc., and the coating film f2 is dried by the drying device 1A. A thin film can be formed.
Also in the formation of the organic layer, when an organic solvent is used for the coating solution and the coating film f2 has a low viscosity, the film thickness is uniform so that the functions required for the organic layer can be obtained by uniform drying by the drying apparatus 1A. This is effective.

As described above, the drying apparatus 1A according to the first embodiment faces the coating film f2 on the transported substrate f1, condenses the solvent vapor from the coating film f2, and condenses the drying plate 11. And a heating device 12 that is disposed at a position facing the condensing plate 11 via the substrate f1 and heats the substrate f1, and is heated so that the temperature of the coating film f2 on the substrate f1 increases stepwise. Heat by device 12. The heating device 12 is disposed to be inclined with respect to the substrate surface so that the distance from the substrate f1 is shortened stepwise in the transport direction y of the substrate f1.

Thereby, the temperature of the coating film f2 can be raised stepwise, and the occurrence of thermal convection due to a rapid temperature rise can be suppressed. The temperature unevenness of the coating film surface due to thermal convection can be suppressed, the evaporation rate of the solvent can be kept constant even in the temperature rising process, and the drying uniformity can be improved.

[Second Embodiment]
In order to raise the temperature of the coating film f2 on the substrate f1 stepwise, a plurality of heating devices having the same surface temperature are opposed to the condenser plate 11 through the substrate f1, and the distance from the substrate f1 is It can also be arranged so as to be shortened stepwise in the transport direction y.

FIG. 4A shows a configuration of a drying apparatus 1B according to the second embodiment. In the thin film forming apparatus 100 described above, a drying apparatus 1B can be used instead of the drying apparatus 1A.
As shown in FIG. 4A, the drying device 1B includes the same condensation plate 11 as the drying device 1A, and includes three

heating devices

141, 142, and 143 at positions facing the condensation plate 11 via the substrate f1. .

The surface temperatures of the heating devices 141 to 143 are all the same. That the surface temperature is the same means that the surface temperature is within a range of about ± 2.5 ° C.
Each of the heating devices 141 to 143 has a planar shape and is disposed in parallel with the substrate surface. Further, each of the heating devices 141 to 143 is arranged such that the distance from the substrate f1 becomes shorter in the order of the heating device 141, the heating device 142, and the heating device 143.
The surface temperatures of the respective heating devices 141 to 143 are the same, but the substrate f1 is heated better as the distance from the respective heating devices 141 to 143 is shortened, so that the temperature of the substrate f1 increases stepwise in the transport direction y. It will be.

As shown in FIG. 4B, the three heating devices 141 to 143 may be arranged so that the distance from the substrate f1 is shortened only within the range of 0 to 30 mm after the condensation drying of the substrate f1 is started. .

[Third Embodiment]
In order to raise the temperature of the coating film f2 on the substrate f1 stepwise, a plurality of heating devices having different surface temperatures are arranged in order from the lowest surface temperature so that the distance from the substrate f1 becomes equal. They can also be arranged side by side in the transport direction y.

FIG. 5 shows a configuration of a drying apparatus 1C according to the third embodiment. In the thin film forming apparatus 100 described above, a drying apparatus 1C can be used instead of the drying apparatus 1A.
As shown in FIG. 5, the drying apparatus 1C includes the same condensation plate 11 as the drying apparatus 1A, and includes three

heating devices

151, 152, and 153 at positions facing the condensation plate 11 through the substrate f1. .

Each of the heating devices 151 to 153 has a planar shape and is arranged side by side in the transport direction y of the substrate f1 so that the distance from the substrate f1 is equal.
The surface temperatures of the heating devices 151 to 153 are different, and the surface temperatures are lower in the order of the heating device 151, the heating device 152, and the heating device 153. For example, when the temperature Th of the coating film surface f2a is adjusted to 60 ° C., a heating device 151 having a surface temperature of 20 ° C., a heating device 152 having a surface temperature of 45 ° C., and a heating device 153 having a surface temperature of 60 ° C. may be used. it can.
Since each of the heating devices 151 to 153 is arranged in the transport direction y in order from the lowest surface temperature, the temperature of the coating film f2 on the substrate f1 increases stepwise in the transport direction y.

[Fourth Embodiment]
Instead of the above-described planar heating devices 151 to 153, a heat roller that incorporates a heat source and heats the substrate f1 may be used.
FIG. 6 shows a configuration of a drying apparatus 1D according to the fourth embodiment using a heat roller. In the thin film forming apparatus 100 described above, a drying apparatus 1D can be used instead of the drying apparatus 1A.
As shown in FIG. 6, the drying apparatus 1D includes the same condensation plate 11 as the drying apparatus 1A, and includes three

heating devices

161, 162, and 163 at positions facing the condensation plate 11 via the substrate f1. .

Each of the heating devices 161 to 163 is a heat roller, and heats the substrate f1 while transporting it.
The surface temperature of each of the heating devices 161 to 163 is lower in the order of the heating device 161, the heating device 162, and the heating device 163. Each of the heating devices 161 to 163 is arranged in the transport direction y of the substrate f1 in order from the one having the same distance to the substrate f1 and the lowest surface temperature. Therefore, the temperature of the coating film f2 on the substrate f1 rises stepwise in the transport direction y.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
In the following examples, “parts” or “%” may be used, and “parts by weight” or “% by weight” is indicated unless otherwise specified.

[Production of drying apparatus K1]
A slit with a width of 2 mm and a depth of 2 mm is formed at intervals of 2 mm in the width direction on one surface of an aluminum plate having a length in the width direction of 400 mm, a length in the transport direction of 200 mm, and a thickness of 20 mm. Then, a condenser plate was produced.

A panel-shaped infrared heater SG4020 (manufactured by YAC DENKO) was prepared as a heating device. The infrared heater SG4020 had a length in the width direction of 400 mm, a length in the transport direction of 200 mm, and a surface temperature of 160 ° C. One infrared heater SG4020 is disposed at a position facing the above-prepared condensing plate through the substrate, and the infrared heater SG4020 is made to the substrate surface so that the distance from the substrate is gradually reduced in the transport direction. Thus, a drying device K1 having the same configuration as the drying device 1A shown in FIG. 1 was produced.

[Production of drying device K2]
In the production of the drying device K1, three infrared heaters SG4020 were arranged in parallel so as to face the substrate at a position facing the produced condensing plate through the substrate. Next, each of the three infrared heaters SG4020 is arranged in a staircase so that the position at which condensation drying is started is 0 mm, and the distance from the substrate is gradually reduced in the transport direction within the range of 0 to 30 mm. Except for this, a drying apparatus K2 was prepared in the same manner as the drying apparatus K1. The drying device K2 has the same configuration as the drying device 1B shown in FIG. 4B.

[Production of drying apparatus K3]
A condenser plate was produced in the same manner as the drying device K1.
In addition, three heat rollers incorporating warm water as a heat source were prepared as heating devices. The surface temperature of each heat roller was 20 ° C, 45 ° C and 60 ° C, respectively. Next, three heat rollers are arranged along the substrate conveyance path in the order of the low surface temperature at the position facing the above-prepared condensing plate through the substrate, and the same configuration as the drying apparatus 1D shown in FIG. A drying device K3 was prepared.

[Production of drying apparatus K21]
In the production of the drying device K1, a drying device K21 was produced in the same manner as the drying device K1, except that one infrared heater SG4020 was arranged in parallel so as to face the substrate.

[Production of drying device K22]
In the production of the drying device K21, a drying device K22 was produced in the same manner as the drying device K21 except that an air nozzle DX-300 (manufactured by Kikuchi Co., Ltd.), which is a hot air dryer, was disposed instead of the condenser plate.

[Preparation of gas barrier film 11]
(Production of substrate)
As the substrate, a polyester film (manufactured by Teijin DuPont Films Co., Ltd., extremely low heat yield PET) whose both surfaces were easily bonded was used. The polyester film had a width in the width direction of 0.35 m, a length in the conveyance direction of 50 m, and a thickness of 125 μm.
On one surface of the substrate, a UV curable organic / inorganic hybrid hard coat agent OPSTAR Z7535 (manufactured by JSR) was applied by a slot method so that the film thickness after drying was 4 μm. After coating, the coating was dried at 80 ° C. for 3 minutes, and cured by irradiation with light of 1.0 J / cm ² using a high-pressure mercury lamp in an air atmosphere to form a bleed-out prevention layer.

Next, UV curable organic / inorganic hybrid hard coat agent OPSTAR Z7501 (manufactured by JSR) is applied to the surface of the substrate opposite to the surface provided with the bleed-out prevention layer so that the film thickness after drying becomes 4 μm. Was applied by the slot method. After application, the coating was dried at 80 ° C. for 3 minutes, and cured by irradiation with 1.0 J / cm ² of light using a high-pressure mercury lamp in an air atmosphere to form a primer layer.

(Production of gas barrier layer)
The produced drying apparatus K1 and coating apparatus were arranged in the same manner as the thin film forming apparatus 100 shown in FIG. As a coating apparatus, a slit type die coater having a width of 0.3 m and a slit interval of 100 μm was used.
On the primer layer of the substrate, a coating film of a gas barrier layer was formed by a coating apparatus, and the coating film was dried by a drying device K1.

In the coating step, as a coating solution, Aquamica NN120-20 (manufactured by AZ Electronic Materials), which is a 20% by mass dibutyl ether solution of perhydropolysilazane, is further diluted with dibutyl ether, and 10% by mass of perhydropolysilazane is dissolved. A butyl ether solution was prepared.

The coating conditions of the coating device are as follows.
(Application conditions)
Substrate transport speed: 10 m / min
Environmental temperature during application: 15 ° C
Applied length in the width direction: 0.3 m
Applied length in transport direction: 50m
The conveyance speed of the substrate was measured with a laser Doppler velocimeter LV203 (manufactured by Mitsubishi Electric Corporation).

The viscosity of the coated film was measured with a digital viscometer HV-50 (manufactured by Brookfield) and found to be 0.5 mPa · s.
Moreover, it was 4 micrometers when the film thickness of the coating film was computed by the following formula.
Coating film thickness = coating amount (g / m ² ) / specific gravity of coating solution (g / m ³ )
Application amount (g / m ² ) = application liquid supply speed (g / sec) / {length in the width direction applied (m) × application speed (m / sec)}

The drying conditions of the drying device K1 are as follows.
(Drying conditions)
Condensing surface temperature Tc: 15 ° C.
Coating surface temperature Th0: 15 ° C
Coating film surface temperature Th1: 20 ° C
Temperature Th2 of coating film surface: 45 ° C
Temperature Th3 of coating film surface: 60 ° C
Distance d between condensation surface and coating film surface: 2 mm
Substrate transport speed: 10 m / min

The distance d between the condensation surface and the coating film surface was adjusted by adjusting the positional relationship between the condensation plate and the substrate transport roller.
Further, the temperatures Th0 to Th3 on the coating film surface are positions where the position where the condensation drying is started by the condenser plate is 0 mm as shown in FIG. 3, and the substrate is transported by 0, 10, 20 and 30 mm from the position. Represents the temperature Th of the coating film surface. The temperature Th0 to Th3 of the coating film surface at each position is measured by a radiation temperature sensor FT-30 (manufactured by Keyence Corporation), and the inclination angle of the infrared heater SG4020 is adjusted in advance so that each temperature Th0 to Th3 becomes the above temperature. did.

After drying, the coating film obtained was irradiated with vacuum ultraviolet light to convert the perhydropolysilazane in the gas barrier layer into silica to obtain a gas barrier layer.
The vacuum ultraviolet light was irradiated using a stage movable xenon (Xe) excimer irradiation apparatus MECLM-1-200 (irradiation wavelength: 172 nm, excimer lamp light intensity: 312 mW / cm ² ) manufactured by MD Excimer. At the time of irradiation, the substrate was transported so that the distance between the light source and the substrate was 1 mm, and the substrate temperature (stage heating temperature) was maintained at 100 ° C. The conveyance speed of the substrate was 1.5 m / min. In addition, the flow rate of nitrogen gas and oxygen gas introduced into the vacuum ultraviolet irradiation chamber is measured with a flow meter, and the nitrogen concentration is adjusted so that the oxygen concentration during irradiation is in the range of 0.2 to 0.4% by volume. The flow rate ratio (nitrogen gas / oxygen gas) of gas and oxygen gas was adjusted.

[Production of gas barrier films 12 and 13]
In the production of the gas barrier film 11, the inclination angle of the infrared heater SG4020 of the drying device K1 is adjusted to change the coating film temperatures Th0 to Th3 to the temperatures shown in Table 1 below and perform condensation drying. Produced the gas barrier films 12 and 13 in the same manner as the gas barrier film 11.

[Preparation of gas barrier film 14]
In the production of the gas barrier film 13, the position at which condensation drying is started by the condenser plate is 0 mm, and the temperature Th of the coating film surface at the position where the substrate is transported 19 mm from the position is measured as the temperature Th2 ^*. Each gas barrier film 14 was produced in the same manner as the gas barrier film 11 except that the drying was performed by adjusting the inclination angle of the infrared heater SG4020 of the drying device K1 so that the temperature Th2 ^* was 60 ° C. .

[Production of gas barrier films 2 and 3]
In preparation of the gas barrier film 11, except that the coating liquid was prepared by changing the dilution of Aquamica NN120-20 so that the viscosity of the coating film of the gas barrier layer was 1.0 and 10.0 mPa · s, respectively. In the same manner as in the gas barrier film 11, gas barrier films 2 and 3 were produced.

[Production of gas barrier films 4 and 5]
In the production of the gas barrier film 11, the

gas barrier films

4 and 5 were produced in the same manner as the drying device K1, except that the drying device K1 was changed to the drying devices K2 and K3, respectively.

[Production of gas barrier films 6 and 7]
In the production of the gas barrier film 11, the gas barrier films 6 and 7 were produced in the same manner as the drying device K1, except that the drying device K1 was changed to the drying devices K21 and K22, respectively.

[Evaluation]
The produced gas barrier films 11 to 14 and 2 to 7 were evaluated as follows.

(1) Uniformity of drying The film thicknesses of the gas barrier layers of the respective gas barrier films 11 to 14 and 2 to 7 were measured using a film thickness measuring device F-20 (manufactured by Filmetrics). The measurement was performed at intervals of 0.01 m in the width direction, changing the position in the transport direction, and 300 measured values were obtained. The maximum value, the minimum value, and the average value of the film thickness were determined from the 300 measured values, and the film thickness variation was determined by the following formula.
Variation in film thickness = {(maximum value−minimum value) / average value} × 100

The obtained film thickness variation was ranked as follows as the uniformity of drying.
5: Variation in film thickness is less than 0.5 and very uniform drying 4: Variation in film thickness is 0.5 or more and less than 1.0, and uniform drying is achieved 3: The film thickness variation is 1.0 or more and less than 5.0, and the film thickness variation is observed, but the film is uniformly dried to a practical level. 2: The film thickness variation is 5.0 or more and 10. It is less than 0, and drying unevenness can be confirmed.
1: Variation in film thickness is 10.0 or more, and there are many drying irregularities

(2) Stability of gas barrier layer The infrared spectrum of each of the gas barrier films 11 to 14 and 2 to 7 is used with Nicolet 380 (manufactured by Thermo Fisher Scientific) at room temperature (temperature 25 ° C., relative humidity 65%). Measured.
After the measurement, the gas barrier films 11 to 14 and 2 to 7 were placed in a constant temperature and humidity oven Yamato Humidic Chamber IG47M (manufactured by Yamato Kagaku Co., Ltd.) adjusted to a high temperature and high humidity of 85 ° C. and 85% relative humidity for 120 hours. Stored continuously. Thereafter, the infrared spectra of the gas barrier films 11 to 14 and 2 to 7 which were returned to room temperature were measured again.
In the absorption band of 800 to 850 cm ⁻¹ of each infrared spectrum measured before and after storage under high temperature and high humidity, the peak intensity of the peak derived from Si—N is obtained, and the peak intensity is stored under high temperature and high humidity. The rate of change before and after was calculated by the following formula.
Change rate of peak intensity = peak intensity after storage / peak intensity before storage

The rate of change of the obtained peak intensity before and after storage was evaluated for rank as follows as the stability of the gas barrier layer.
5: Change rate of peak intensity is less than 0.5 and shows very excellent stability 4: Change rate of peak intensity is 0.5 or more and less than 0.7 and shows excellent stability 3: The peak intensity change rate is 0.7 or more and less than 0.8, and shows a practically stable degree. 2: The peak intensity change rate is 0.8 or more and less than 0.9, and the stability is low. : The rate of change in peak intensity is 0.9 or more, and the stability is very low

(3) Gas barrier properties The water vapor permeability (g / m ² · 24 h) of each of the gas barrier films 11 to 14 and 2 to 7 was determined by the calcium corrosion method described in JP-A-2005-283561.
First, the gas barrier films 11 to 14 and 2 to 7 are cut out, and using a vacuum deposition apparatus JEE-400 (manufactured by JEOL Ltd.), calcium is vapor-deposited on a part of the cut out sample to obtain 12 mm × 12 mm calcium. Nine layers were provided. At the time of vapor deposition, the portions other than each calcium layer were masked.

The mask was removed in a vacuum state, and aluminum was deposited from another deposition source to cover the entire surface including the calcium layer, thereby forming a sealing layer. Next, the vacuum state is released, and it is quickly transferred to a dry nitrogen gas atmosphere, and an ultraviolet curable resin T470 / UR7134 (manufactured by Nagase ChemteX) is applied on the film surface on which the sealing layer is formed. Quartz glass having a thickness of 0.2 mm was disposed. An evaluation cell was produced by irradiating ultraviolet light through quartz glass to cure the ultraviolet curable resin.

The obtained cells for evaluation of the gas barrier films 11 to 14 and 2 to 7 were stored continuously in a constant temperature and humidity oven Yamato Humidic Chamber IG47M adjusted to a temperature of 85 ° C. and a relative humidity of 85% for 120 hours.
From each image obtained by photographing the evaluation cell when the storage time T (h) is T = 0 and T = 120, a corrosion area of calcium was extracted by image processing. From the area of the extracted corrosion area, the amount of water vapor required for corrosion was calculated as the amount of water vapor permeation by the following formula.
Water vapor transmission rate (g / m ² · 24 h) = X × 18 × 2 × (10 ⁴ / A) × (24 / T)

In the above formula, X represents the molar amount of calcium hydroxide produced by the reaction of calcium with water, and is represented by X = (δ × d ₀ × α × d ₂ ) / M ₂ .
A represents the area (cm ² ) of the calcium layer.
δ represents the area (cm ² ) of the corrosion region of the calcium layer. d ₀ represents the thickness (cm) of the calcium layer. α is a correction factor for the thickness of the calcium layer, and is determined within a range of 1 <α ≦ (M ₂ / d ₂ ) / (M ₁ / d ₁ ). d ₁ represents the density of calcium (g / cm ³ ), and d ₂ represents the density of calcium hydroxide (g / cm ³ ). M ₁ represents the molecular weight of calcium, and M ₂ represents the molecular weight of calcium hydroxide.

From the respective water vapor transmission amounts obtained when T = 0 and T = 120, the rate of change of the water vapor transmission amount before and after storage under high temperature and high humidity was determined as the water vapor transmission rate by the following formula.
Water vapor permeability ^(g / m 2 · 24h)
= (Water vapor transmission amount when T = 0) / (Water vapor transmission amount when T = 120)

The obtained water vapor permeability was ranked as follows as gas barrier properties under high temperature and high humidity.
5: Water vapor permeability is less than 0.1 and shows very good gas barrier properties 4: Water vapor permeability is 0.1 or more and less than 0.3 and shows excellent gas barrier properties 3: Water vapor permeability is It is 0.3 or more and less than 0.6, and shows a practical gas barrier property. 2: Water vapor permeability is 0.6 or more and less than 0.8, and gas barrier property is low 1: Water vapor permeability is 0.8 or more. Yes, gas barrier property is very low

Table 1 below shows the evaluation results.
In Table 1, the temperature Th2 ^* is displayed in the column of the temperature Th2 of the gas barrier film 14.

As shown in Table 1 above, according to the gas barrier films 11 to 14 and 2 to 5 according to the examples, even when the viscosity of the coating film is as low as about 0.5 or 1.0 mPa · s, Uniform drying is possible, and sufficient storage stability and gas barrier properties of the gas barrier layer are obtained. Compared with the gas barrier film 6 according to the comparative example, it is surmised that the heat convection is suppressed by the stepwise temperature increase of the coating film and uniform drying is possible.
According to the gas barrier films 6 and 7 according to the comparative examples, the uniformity of drying becomes insufficient, and the performance required as a gas barrier layer is not obtained. This is presumably because when the viscosity of the coating film is low, liquid flow due to convection occurs or thermal convection due to rapid heating occurs, and the evaporation rate of the solvent is not constant on the surface of the coating film.

The present invention can be used in a drying apparatus and a drying method for condensing solvent vapor from a coating film.

100 Thin film forming device f1 Substrate f2 Coating film f2a Coating film surface 1A to 1D Drying device 11 Condensing plate

11a Condensing surface

12, 141 to 143, 151 to 153, 161 to 163 Heating device 3 Coating device

Claims

A condensing plate facing the coating film on the substrate to be transported, condensing the solvent vapor from the coating film and drying;
One or a plurality of heating devices that are disposed at positions facing the condenser plate via the substrate and heat the substrate,
A drying apparatus, wherein the heating apparatus heats the coating film on the substrate so that the temperature of the coating film increases stepwise.
The said 1 or several heating apparatus is inclined and arrange | positioned with respect to the board | substrate surface so that the distance with the said board | substrate may shorten in steps in the conveyance direction of the said board | substrate. The drying apparatus as described.
The heating devices are arranged such that the surface temperatures of the plurality of heating devices are the same, and the distance from the substrate is gradually reduced in the transport direction of the substrate. The drying apparatus as described.
The plurality of heating devices are arranged in the transport direction of the substrate in order from the lowest surface temperature so that the surface temperatures of the plurality of heating devices are different from each other and the distance from the substrate is equal. The drying apparatus according to claim 1.
The drying device according to any one of claims 1 to 4, wherein the one or more heating devices perform heating by radiant heat.
The drying apparatus according to any one of claims 1 to 5, wherein the coating film has a viscosity of 100 mPa · s or less.
The drying apparatus according to any one of claims 1 to 6, wherein the coating film contains a silicon compound having a polysilazane skeleton.
A condensing plate facing the coating film on the substrate to be conveyed is a drying method for condensing and drying the solvent vapor from the coating film,
The substrate is heated so that the temperature of the coating film on the substrate increases stepwise by one or a plurality of heating devices disposed at positions facing the condenser plate via the substrate. How to dry.