JP2009034620A - Method of manufacturing optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical film which controls deformation of the film, e.g. wrinkling and curling, due to heat and hardening shrinkage of the coating film produced on irradiation of UV rays and deterioration of film characteristics of a formed functional film, e.g. the hardness, scratch resistance and adhesiveness to the substrate, in hardening a coating film containing a UV-hardenable resin by irradiating the film with UV rays so as to obtain a functional film having a good appearance and good film characteristics. <P>SOLUTION: The method is characterized by adjusting the temperature, Ti(°C), of the coating film after the drying process and before the UV irradiation process to 25-80°C and the temperature change per unit time, ΔT/t(°C/sec), to 6-18°C/sec, wherein t(sec) is the UV irradiation time for the coating film in the UV irradiation process, and ΔT(°C) is the temperature rise of the coating film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing an optical film in which a functional film is formed by applying a coating film containing an ultraviolet curable resin on a web-like support such as a plastic film, and drying and ultraviolet curing the coating film. .

On the surface of various displays typified by liquid crystal displays, a hard coat film for protecting the inside of the liquid crystal on the base film, or anti-reflection to prevent contrast degradation and image reflection due to reflection of external light An optical film on which a functional film such as a film is formed is provided. These functional films such as hard coat films and antireflection films are formed on a web-like support that is continuously conveyed by ionizing radiation curable resins such as ultraviolet curable resins or electron beam curable resins, or thermosetting. It is formed by passing through a step of applying a coating liquid containing a resin or the like, a step of drying the coating film applied on the support, and a step of curing the coating film on the support.
Here, when a functional film is formed by applying a coating liquid containing an ultraviolet curable resin on a support, when curing is performed by irradiating the coating film on the support with ultraviolet rays, Due to curing shrinkage of the film, problems such as deformation of the optical film such as wrinkles and curls, film characteristics such as the hardness of the functional film and scratch resistance, and a decrease in adhesion between the base film and the functional film occur.

  Therefore, in the method of curing the coating film on the support with ultraviolet rays, many methods have been proposed to solve various problems (see Patent Documents 1 to 5).

According to the method of Patent Document 1, a coating film of ionizing radiation curable resin is formed on a plastic base film that shrinks when heated, and the base film is irradiated with ionizing radiation while being heated. By curing the coating film under a condition where the difference between the thermal shrinkage rate of the material film and the curing shrinkage rate of the coating film is 2.0% or less, it is substantially flat without curling and has no trouble in various processing. A film can be obtained.
According to the method of Patent Document 2, the temperature difference between the front surface and the back surface of the film is 30 ° C. or lower, or the glass transition temperature of the transparent resin or lower, 40 ° C. or higher, and adjusted within a variation range of ± 3 ° C. By curing the UV curable resin by bringing the film into contact with a support whose temperature is adjusted with a medium, the UV curable resin is efficiently and uniformly cured without deforming the base film, and sufficient adhesion is obtained. The obtained laminated film is obtained.
According to the method of Patent Document 3, in a cooling gas atmosphere, the dried coating film is irradiated with ultraviolet rays while being cooled so that the surface temperature of the organic polymer film is 70 ° C. or less, and the thickness is 3 to 30 μm. By forming this cured coating film, a coated film with good appearance and good adhesion can be obtained.
According to the method of Patent Document 4, curling is suppressed to be small even when the hard coat layer is thickened by forming the hard coat layer by curing the curable resin while the base film is held in a curved surface state. Can do.
According to the method of Patent Document 5, by irradiating ultraviolet rays while maintaining the temperature change of the laminated film from the end of the drying process to the ultraviolet irradiation process within 30 ° C., the scratch resistance is high and the product film is deformed. The adhesion of the ultraviolet curable resin component to the substrate film can be improved without causing it.
Japanese Patent Laid-Open No. 3-19839 JP 2006-152134 A JP 2006-159054 A JP 2006-218449 A JP 2007-98302 A

However, in the method described in Patent Document 1, the absolute value of the heat shrinkage rate of the base film and the curing shrinkage rate of the coating film is increased by heating, and even if the difference between these shrinkage rates is controlled, Deformation occurs. Further, when the thickness of the coating film is large, the absolute value of the curing shrinkage rate becomes large, and curling cannot be suppressed even if the difference in shrinkage rate is controlled.
In the method described in Patent Document 2, even when the temperature difference between the front surface and the back surface of the film is 30 ° C. or less, the curing shrinkage rate of the coating film increases as the temperature of the back surface of the film increases, and curling of the film is particularly suppressed. I can't.
In addition, in the method described in Patent Document 3, deformation of the film due to heat is suppressed, but the coating film is not efficiently cured by setting the surface temperature to 70 ° C. or less, and the hardness and scratch resistance of the functional film, etc. The film characteristics deteriorate.
Further, in the method described in Patent Document 4, curling can be suppressed even when the hard coat layer is thick, but deformation of the film due to heat generated during ultraviolet irradiation cannot be suppressed. In particular, when the hard coat layer is thick, the film is significantly deformed.
In addition, the method described in Patent Document 5 can improve the scratch resistance of the coating film and the adhesion to the base film, but if the temperature of the base film increases rapidly due to heat generated during ultraviolet irradiation, the film Deformation occurs.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a coating containing an ultraviolet curable resin on a continuously transported support (hereinafter also referred to as a substrate or a substrate film). Applying the liquid, drying the applied coating, and curing the coating by irradiating with ultraviolet rays, the heat generated simultaneously with the ultraviolet rays and the film such as wrinkles and curls in the transport direction due to the curing shrinkage of the coating Provided is a method for producing an optical film that suppresses deformation, deterioration of film properties such as hardness and scratch resistance of the formed functional film, adhesion to a substrate, and the like, and obtains a functional film having good appearance and film physical properties. It is in.

  The present inventors, when curing a coating film on a web-like support continuously conveyed by ultraviolet irradiation, changes the temperature of the support before irradiation and the temperature of the coating film during irradiation per unit time. The inventors have found that controlling the amount suppresses deformation of the film and deterioration of film properties of the coating film, and the present invention has been achieved.

  That is, in order to achieve the above object, the method for producing an optical film of the present invention forms a coating film on the support by applying a coating liquid containing an ultraviolet curable resin onto the support that is continuously conveyed. An application step for drying, a drying step for drying the coating film applied on the support in the application step, and an ultraviolet irradiation step for curing the coating film by irradiating the coating film dried in the drying step with ultraviolet rays. In the manufacturing method of the optical film, the temperature Ti (° C.) of the coating film after the drying step and before the ultraviolet irradiation step is set to 25 or more and 80 or less, and the ultraviolet irradiation time in the ultraviolet irradiation step is t (sec). ) When the temperature rise of the coating film due to ultraviolet irradiation is ΔT (° C.), the temperature change ΔT / t (° C./sec) per unit time of the coating film during ultraviolet irradiation is 6 or more and 18 or less. It is characterized by.

According to the method for producing an optical film of the present invention, when the coating film on the continuously conveyed support is cured by ultraviolet irradiation, the temperature Ti (° C.) of the coating film after the drying process and before the ultraviolet irradiation process is set. Unit time at the time of UV irradiation when the UV irradiation time is set to 25 (T) and the temperature rise of the coating film due to UV irradiation is ΔT (° C.). The temperature change ΔT / t (° C./sec) of the hit coating film is set to 6 or more and 18 or less.
Due to this, heat generated simultaneously with ultraviolet rays, film deformation such as wrinkles and curls due to curing shrinkage of the coating film, deterioration of film properties such as hardness and scratch resistance of the formed functional film, adhesion to the substrate, etc. Can be suppressed, and a method for producing an optical film capable of obtaining a functional film having good appearance and film properties can be provided.
When the temperature Ti (° C.) of the coating film is 25 or more and 80 or less, the coating film is efficiently cured, and as a result, film properties such as hardness and scratch resistance of the functional film are improved. On the other hand, if the temperature Ti (° C.) of the coating film is higher than 80, thermal damage to the film is large, and defects in appearance such as film deformation occur. On the other hand, when the temperature Ti (° C.) of the coating film is less than 25, the coating film is not efficiently cured, and film properties such as hardness and scratch resistance of the functional film are deteriorated.
Further, when the temperature change ΔT / t (° C./sec) of the coating film per unit time during ultraviolet irradiation is 6 or more and 18 or less, deformation of the film due to heat or curing shrinkage can be suppressed. When the temperature change ΔT / t (° C./sec) of the coating film per unit time is greater than 18, even if the temperature rise is the same due to the rapid temperature rise of the coating film, the unit time When the temperature change per unit is large, the film is likely to be deformed, and the adhesiveness between the base film and the coating film is lowered due to rapid curing shrinkage. On the other hand, when the temperature change ΔT / t (° C./sec) of the coating film per unit time is smaller than 6, deformation of the film can be suppressed, but curing by heat is not promoted, and the film such as hardness and scratch resistance is not present. Characteristics are degraded.

Hereinafter, the manufacturing method of the optical film of this invention is demonstrated with reference to drawings.
Drawing 1 is a figure showing a manufacturing method of an optical film of an embodiment.
The method for producing an optical film of the embodiment comprises that a web-like support (base material) 9 is continuously unwound from a film roll 1 and conveyed, and a coating roll 2, a coating device (die head) 3, a drying device 5 and The film is wound around a film roll 7 through an ultraviolet irradiation device 6. The coating apparatus 3 forms a coating film by applying a coating liquid on the transported support by the coating apparatus 3 (application process). The drying device 5 evaporates the solvent in the coating film on the transported support (drying process). The ultraviolet irradiation device 6 cures the coating film on the conveyed support (ultraviolet irradiation step).

  The coating method by the coating device 3 includes a wet coating method (dip coating method, flow coating method, spray coating method, roll coating method, gravure roll coating method, air doctor coating method, wire doctor coating method, knife coating method, reverse coating method. Method, transfer roll coating method, micro gravure coating method, kiss coating method, cast coating method, slot orifice coating method, calendar coating method, die coating method, etc.). Although the die coating method is shown in the coating apparatus 3 in FIG. 1, it is only necessary that a coating film can be continuously formed on the support by a roll-to-roll method, and the present invention is not limited to this.

  As a drying method using the drying device 5, there is a method of spraying hot air directly on a coating film formed by applying a coating liquid on the support 9 to promote evaporation of the solvent in the coating film. The temperature of the hot air at this time is generally 50 ° C. to 150 ° C., but the speed and temperature of the hot air are adjusted in consideration of the residual solvent amount in the coating film and the drying speed of the solvent. Further, since direct appearance of hot defects such as drying unevenness may occur when hot air is blown directly, there is a method of heating the substrate indirectly without blowing hot air directly.

In the ultraviolet curing method using the ultraviolet irradiation device 6, the coating film on the support 9 can be cured by various lamps such as a high-pressure mercury lamp and a metal halide lamp.
In this invention, it is preferable that the temperature Ti (degreeC) of the coating film after a drying process and before an ultraviolet irradiation process is 25-80. When the temperature Ti (° C.) of the coating film is 25 or more and 80 or less, the coating film is efficiently cured, and as a result, film properties such as hardness and scratch resistance of the functional film are improved. On the other hand, if the temperature Ti (° C.) is higher than 80, thermal damage to the film is large, and defects in appearance such as film deformation occur. On the other hand, when the temperature Ti (° C.) is less than 25, the coating film is not efficiently cured, and the film characteristics such as hardness and scratch resistance of the functional film are deteriorated.

  The temperature Ti of the coating film after the drying process and before the ultraviolet irradiation process is preferably adjusted before the ultraviolet irradiation. For example, as in the present invention, the temperature of the coating film can be controlled by providing a temperature control mechanism on the guide roll 4b in front of the ultraviolet irradiation device 6. Moreover, since the temperature of the coating film rises by the drying device 5 and the temperature of the coating film decreases after leaving the drying device 5 due to the temperature in the atmosphere, the distance from the drying device 5 to the ultraviolet irradiation device 6 is increased. The temperature of the coating film can also be controlled by adjusting. The temperature Ti of the coating film can also be controlled by adjusting the temperature in the drying device 5.

  Furthermore, the change in temperature per unit time of the coating film during UV irradiation when the UV irradiation time of the coating film in the UV irradiation process is t (sec) and the temperature rise of the coating film due to UV irradiation is ΔT. ΔT / t (° C./sec) is preferably 6 or more and 18 or less. When the temperature change ΔT / t (° C./sec) per unit time of the coating film is 6 or more and 18 or less, deformation of the film due to heat or curing shrinkage can be suppressed. If the temperature change ΔT / t (° C./sec) per unit time of the coating film is greater than 18, even if the temperature rise is the same, the unit time When the temperature change per hit is large, the film is likely to be deformed, and the adhesiveness between the base film and the coating film is lowered due to rapid curing shrinkage. On the other hand, if the temperature change ΔT / t (° C./sec) per unit time of the coating film is smaller than 6, deformation of the film can be suppressed, but curing due to heat is not promoted, and films such as hardness and scratch resistance are not present. Characteristics are degraded.

  Regarding the temperature change ΔT / t (° C./sec) per unit time of the coating film during the ultraviolet irradiation in the ultraviolet irradiation process, the transport speed of the support 9 is changed or the output of the lamp of the ultraviolet irradiation device 6 is changed. Can be adjusted. Further, the irradiation time can be controlled by arranging a plurality of ultraviolet irradiation devices 6. In addition, when the can roll 8 is provided so as to face the ultraviolet irradiation device 6 with the support 9 interposed therebetween, the can roll 8 includes a temperature control mechanism, and the temperature of the can roll 8 is changed, so that the ultraviolet irradiation is performed. The time change ΔT / t of the coating temperature at the time can be set to a desired range.

Moreover, it is preferable that the maximum illumination intensity W (mW / cm < ² >) of the ultraviolet-ray irradiated to a coating film at an ultraviolet irradiation process is 100-800. The maximum illuminance W refers to the highest illuminance among the illuminances of ultraviolet rays applied to the coating film on the support 9 to be conveyed. When the maximum illuminance W (mW / cm ² ) of the ultraviolet rays is greater than 800, heat is excessively applied to the film and is greatly deformed. When the maximum illuminance W (mW / cm ² ) of ultraviolet rays is smaller than 100, sufficient curing is not achieved, and the hardness and scratch resistance of the functional film are lowered.
Regarding the illuminance, excessive illuminance can be controlled by changing the type of lamp and lamp output.

  Moreover, it is preferable that the film thickness of the coating film after a drying process and before an ultraviolet irradiation process is 0.1-50 micrometers. The film thickness of the coating film before ultraviolet irradiation can be measured using an infrared film thickness meter (for example, a film thickness meter RX-100, manufactured by Kurashiki Textile Co., Ltd.). When the film thickness of the coating film before ultraviolet irradiation is larger than 50 μm, the curing shrinkage of the coating film increases and the deformation of the film increases. On the other hand, when the film thickness of the coating film before ultraviolet irradiation is smaller than 0.1 μm, the desired hardness and scratch resistance of the functional film may not be exhibited.

Next, the optical film of the present invention will be described.
FIG. 2 shows the optical film of the present invention.
As shown in FIG. 2, the optical film 12 of the present invention is composed of a base film (support 9) 10 and a functional film 11. The functional film 11 has high hardness, antireflection, antiglare, antistatic. Functionality such as sex is added. The functional film 11 may be a laminate of two or more films from the viewpoint of imparting functionality.

  As the web-like support 9 (base film 10) used in the present invention, a plastic film can be used. The plastic film only needs to have appropriate transparency and mechanical strength. Examples of the plastic film include polyethylene terephthalate (PET), triacetyl cellulose (TAC), diacetyl cellulose, acetyl cellulose butyrate, polyethylene naphthalate (PEN), cycloolefin polymer, polyimide, polyethersulfone (PES), and polymethyl. Films such as methacrylate (PMMA) and polycarbonate (PC) can be used. Especially, when using the laminated body of this invention for the front surface of a liquid crystal display device, since there is no optical anisotropy, a triacetylcellulose (TAC) film is used preferably.

  The coating liquid of the present invention includes the following ultraviolet curable resin, a solvent for dissolving the resin, and a photopolymerization initiator for curing the resin. In addition, a leveling agent, an ultraviolet absorber, an infrared absorber, Various additives such as a stain and a water repellent can be added as necessary.

  The resin used as the ultraviolet curable material of the present invention is synthesized from polyfunctional acrylates such as polyhydric alcohol acrylic acid or methacrylic acid ester, diisocyanate and polyhydric alcohol, and acrylic acid or methacrylic acid hydroxy ester. And polyfunctional urethane acrylate. Besides these, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can also be used. These resins may be used alone, but may be used as a mixture of two or more. In addition, these resins include silica particles, acrylic particles, acrylic-styrene particles, styrene particles, melamine particles, talc, various aluminosilicates, kaolin clay, MgAl hydrotalcite, etc., calcium fluoride particles, fluoride Low refractive particles such as magnesium particles and porous silica particles, and conductive particles such as metal particles may be contained to impart antireflection properties, antiglare properties, antistatic properties and the like to the coating film.

  In forming the coating liquid, a solvent can be added as necessary. At this time, the solvent is not particularly limited, but water, alcohols such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, acetone, etc. in consideration of the stability of the composition and the volatility with respect to the coating layer. -Ketones such as methyl ethyl ketone and methyl isobutyl, 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, ethyl cellosolve, butyl cellosolve and ethyl Glycol ethers such as carbitol and butyl carbitol, aliphatic hydrocarbons such as hexane, heptane and octane, halogenated hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene, N-methylpyrrolidone, di It is suitably selected from such a solution of triethylsilane. These solvents may be used alone or as a mixture of two or more.

  Examples of the photopolymerization initiator (radical polymerization initiator) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2-methyl [4- (methylthio) phenyl] morpholinopro. Pan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propane -1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide Etc. The addition amount of the photopolymerization initiator is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the ultraviolet curable material.

<Method for producing optical film>
In the following manner, the functional film 11 was formed on the support 9, and optical films 12 of Examples and Comparative Examples were produced.

  100 parts by weight of pentaerythritol triacrylate (PE-3A, manufactured by Kyoeisha Chemical Co., Ltd.) as an ultraviolet curable resin, 100.5 parts by weight of toluene as a solvent, and 5 parts by weight of Irgacure 184 (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator The mixture was mixed to prepare a coating solution.

Next, a coating liquid having the above composition was applied using a triacetyl cellulose (hereinafter referred to as TAC) film having a width of 650 mm as the support 9 to be continuously conveyed and using an extrusion type die head as the coating device 3. The applied coating film was dried with hot air at 50 ° C. in the drying apparatus 5 and then cured with a high-pressure mercury lamp (80 W / cm) installed in the ultraviolet irradiation apparatus 6 to form a functional film on the TAC film. In addition, the conveyance speed of the support body 9 is 15 m / min.
Moreover, the guide roll 4b in front of the ultraviolet irradiation device 6 and the can roll 8 in the ultraviolet irradiation device 6 were those having a temperature control mechanism.

  Then, a radiation temperature sensor (FT-H20, manufactured by Keyence Corporation) is installed before and immediately after the ultraviolet irradiation device 6, and the temperature Ti (° C.) of the coating film before irradiation with ultraviolet rays and the time for irradiation with ultraviolet rays t ( sec), the time change ΔT / t (° C./sec) of the coating temperature at the time of ultraviolet irradiation, when ΔT (° C.) is the temperature rise of the coating film due to the irradiation with ultraviolet rays. The ultraviolet irradiation time t (sec) was obtained from the ultraviolet irradiation width of the ultraviolet irradiation device 6 and the conveyance speed.

  By changing the temperature of the guide roll 4b in front of the ultraviolet irradiation device having the temperature control mechanism and the temperature of the can roll 8 in the ultraviolet irradiation device 6 having the temperature control mechanism, as shown in Table 1, before irradiation with ultraviolet light The optical film of Examples and Comparative Examples was prepared by changing the temperature Ti (° C.) of the coating film and the time change ΔT / t (° C./sec) of the coating temperature during ultraviolet irradiation.

<Evaluation method>
Wrinkle evaluation, curl evaluation, pencil hardness, scratch resistance, and adhesion between the functional film and the TAC film of the obtained optical film were evaluated by the following methods.

(Wrinkle evaluation)
Regarding the evaluation of wrinkles of the obtained optical film, the optical film 12 was cut into a width of 650 mm × 1 m, and the cut-out optical film was applied to a fluorescent lamp for visual evaluation. Evaluation was carried out in the following three stages.
3: Wrinkles cannot be confirmed.
2: Wrinkles parallel to the film transport direction are difficult to check.
1: Wrinkles parallel to the film transport direction can be clearly confirmed.

(Curl evaluation)
Regarding the curl evaluation of the obtained optical film, the optical film was cut out 10 cm × 10 cm, the cut out optical film was placed on a flat desk, and the degree of curling was evaluated visually. Evaluation was carried out in the following three stages.
3: There is almost no curl lifting.
2: The rise of curl is large.
1: Curl lift is cylindrical.

(Pencil hardness test)
According to JIS-K-5400, the scratch of the functional film on the TAC film was evaluated by a pencil scratch tester.

(Abrasion resistance test)
The functional film on the TAC film was rubbed 10 reciprocally with a weight of 250 g with steel wool (# 0000), and the scratching was visually evaluated. The method of scratching was evaluated in the following three stages.
3: Scratches cannot be confirmed.
2: Dozens of scratches can be confirmed.
1: Many scratches can be confirmed.

(Adhesion test)
Evaluation was made by a cross-cut tape method. A grid-like square was formed on the functional film on the TAC film with a cutter knife, and a cellophane tape was affixed thereon, and the number of 100 squares that had not been peeled off (remaining number) was counted.

  As is clear from Table 1, by controlling the temporal change of the coating film temperature before irradiation and the coating film temperature at the time of irradiation, the heat generated simultaneously with ultraviolet rays and the film such as wrinkles and curls due to curing shrinkage of the coating film It was possible to suppress the deterioration of film physical properties such as deformation, hardness and scratch resistance of the formed functional film, and adhesion to the substrate.

It is a figure which shows the manufacturing method of the optical film of embodiment. It is sectional drawing of an optical film.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Unwinding roll film, 2 ... Coating roll, 3 ... Die head, 4a-4c ... Guide roll, 5 ... Drying device, 6 ... Ultraviolet irradiation device, 7 ... Winding roll film, 8 ... ... can roll, 9 ... support, 10 ... base film, 11 ... functional film, 12 ... optical film.

Claims (4)

A coating process in which a coating liquid containing an ultraviolet curable resin is coated on a continuously conveyed support to form a coating film on the support, and a coating film coated on the support in the coating process In a method for producing an optical film, comprising: a drying step of drying the coating; and an ultraviolet irradiation step of curing the coating film by irradiating the coating film dried in the drying step with ultraviolet rays.
The coating film by which the temperature Ti (° C.) of the coating film after the drying process and before the ultraviolet irradiation process is 25 or more and 80 or less, and the ultraviolet irradiation time is t (sec) in the ultraviolet irradiation process. The temperature change ΔT / t (° C./sec) per unit time of the coating film at the time of ultraviolet irradiation was set to 6 or more and 18 or less, where ΔT (° C.) was the temperature rise.
The manufacturing method of the optical film characterized by the above-mentioned. ^{2. The} method for producing an optical film according to claim 1, wherein a maximum illuminance W (mW / cm ² ) of ultraviolet rays applied to the coating film in the ultraviolet irradiation step is 100 or more and 800 or less.   The method for producing an optical film according to claim 1 or 2, wherein a film thickness of the coating film after the drying step and before the ultraviolet irradiation step is 0.1 µm or more and 50 µm or less.   The temperature of the coating film before the said ultraviolet irradiation process is adjusted after the said drying process by using 1 or 2 or more guide rolls which have a temperature control function in any one of Claims 1-3 characterized by the above-mentioned. The manufacturing method of the optical film of description.

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