TW201833200A - Production method for film provided with coating layer - Google Patents

Abstract

Provided is a production method for an optical film that is provided with a coating layer that is formed on a thin film. The production method makes it possible to produce a film that is provided with a coating layer and does not wrinkle, etc. This production method for a film that is provided with a coating layer involves: laminating a protective sheet on one surface of a film that has a thickness of no more than 25 [mu]m and a bending resistance of no more than 40 mm; and forming a coating layer on the other surface of the film. The protective sheet has an arithmetic average surface roughness Ra of no more than 0.1 [mu]m and a bending resistance of at least 40 mm.

Description

Method for manufacturing film with coating layer

The present invention relates to a method of producing a film with a coating layer.

Generally, a coating layer capable of exhibiting various functions is provided on the surface of an image display device such as a liquid crystal display (LCD), a cathode ray tube display device (CRT), a plasma display (PDP), or an electroluminescence display (ELD). . For example, a hard coat layer for preventing damage due to contact with the outside and an anti-glare layer for improving the anti-glare property are provided. Previously, such a coating layer was provided by laminating a surface film (for example, a hard coat film or an anti-glare film) composed of a coating layer and a substrate on a member of an image display device. On the other hand, in recent years, the image display device has been developed in a thinner direction. Accordingly, the industry is investigating the thinning of a substrate constituting a surface film, and further studies the formation of a coating layer on a thin optical film. However, when a coating layer is formed on a thin optical film or the like, there is a problem that wrinkles are likely to occur in the coating layer forming step (for example, in the hard coat layer hardening treatment), which tends to cause poor appearance, poor optical properties, and the like. . Further, a method of supporting an optical film with a protective sheet at the time of forming a coating layer is conceivable, but in the case of employing the method, there is a problem in that, under the heating of the coating layer forming step, the protective sheet is uneven, and the unevenness is transferred. Printed onto the optical film. In view of the above, the industry has demanded a technique for forming a coating layer without wrinkles even when a thin film is used. [Prior Art Document] [Patent Document] Patent Document 1: Japanese Patent Laid-Open No. 2016-68497

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above-mentioned problems, and an object of the invention is to provide a method for producing a film with a coating layer which is capable of forming a coating layer of a thin film and capable of forming a coating layer A film with a coating layer is produced without wrinkles or the like. [Technical means for solving the problem] The method for producing a film with a coating layer according to the present invention comprises: protecting a sheet of an area layer of a film having a thickness of 25 μm or less and a stiffness of 40 mm or less, and the film The other surface is formed with a coating layer; the surface of the protective sheet opposite to the film has an arithmetic mean surface roughness Ra of 0.1 μm or less, and the protective sheet has a stiffness of 40 mm or more. In one embodiment, the protective sheet includes a substrate and an adhesive layer formed on the substrate, and the adhesive side of the protective sheet is bonded to the film. In one embodiment, the thickness of the adhesive layer is 10 μm or less. In one embodiment, the protective sheet is laminated on the film in a peelable manner. In one embodiment, the film is an optical film. In one embodiment, the coating layer is made of a curable resin. In one embodiment, the curable resin is photocurable. In one embodiment, the curable resin is thermosetting. In one embodiment, the thickness of the coating layer is 4 μm or less. [Effects of the Invention] According to the present invention, a film is supported by using a protective sheet having a specific surface roughness Ra and stiffness, and a coating layer is formed on the film to prevent the occurrence of wrinkles. A film with a coating layer attached thereto.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining a manufacturing method of the present invention in an embodiment of the present invention. The method for manufacturing a film with a coating layer according to the present invention is a method for forming a coating layer 10 on a thin film 20, which comprises: protecting a sheet 30 in an area layer of a thin film 20 (Fig. 1 (a)); The coating layer 10 is formed on the other side of the film 20 (the side opposite to the side on which the protective sheet 30 is laminated) (Fig. 1 (b)). In one embodiment, the protective sheet 30 is peelably laminated to the film 20. In one embodiment, after the coating layer 10 is formed to obtain a film with a coating layer, the protective sheet 30 is peeled off (FIG. 1(c)). The thickness of the above film is 25 μm or less. In the present invention, even if a film having a small thickness and which is prone to wrinkles is used, the coating layer can be formed without preventing wrinkles. The thickness of the film can be appropriately set depending on the use. In one embodiment, the thickness of the film is 20 μm or less. In another embodiment, the film has a thickness of 15 μm or less. The lower limit of the thickness of the film is, for example, 1 μm. The film has a stiffness of 40 mm or less. According to the present invention, even if a film having a small stiffness (i.e., no plasticity) which is inevitably wrinkled by the prior method is used, the coating layer can be formed without preventing wrinkles. In one embodiment, a film having a stiffness of 5 mm to 35 mm can be used. In another embodiment, a film having a stiffness of 5 mm to 25 mm can be used. Further, in the present specification, the stiffness is measured in accordance with JIS L1096 (45°, cantilever method). The determination method is detailed below. The film is preferably light transmissive. In one embodiment, the film has a light transmittance of 40% or more, preferably 45% to 50%. In another embodiment, the film has a light transmittance of 70% or more, more preferably 80% or more, still more preferably 90% or more. In one embodiment, an optical film is used as the film. Examples of the optical film include a retardation film, a polarizing film (a polarizing element, or a polarizing plate composed of a polarizing element and a protective film), a brightness improving film, a light diffusing film, and a light collecting film. As the material constituting the above film, any suitable material can be employed. For example, polycarbonate resin, polyvinyl acetal resin, cycloolefin resin, acrylic resin, cellulose ester resin, cellulose resin, polyester resin, polyester carbonate resin, and olefin system Resin, polyurethane resin, and the like. Preferably, a resin which can be used as a material of an optical film such as a polycarbonate resin, a polyvinyl acetal resin, a cellulose ester resin, a polyester resin or a polyester carbonate resin; a polyvinyl alcohol film; A hydrophilic polymer film (a film which is a material of a polarizing element) such as a formalized polyvinyl alcohol film or an ethylene-vinyl acetate copolymer partially saponified film. The film may have a laminated structure composed of a plurality of layers. <Layer of Protective Sheet> The arithmetic surface roughness Ra of the surface of the protective sheet opposite to the film is 0.1 μm or less, preferably 0.08 μm or less, more preferably 0.05 μm or less. The smaller the arithmetic surface roughness Ra of the protective sheet is, the lower limit is, for example, 0.01 μm. In addition, in this specification, arithmetic surface roughness Ra is measured based on JIS B0601. The protective sheet has a stiffness of 40 mm or more, preferably 45 mm or more, more preferably 50 mm or more, and still more preferably 60 mm or more. In the present invention, as described above, a protective sheet having a small arithmetic surface roughness Ra and a high rigidity is used, and the protective sheet is used to support the above-mentioned film, whereby generation of wrinkles at the time of formation of the coating layer can be suppressed. . More specifically, it is possible to prevent shrinkage of the film due to heating at the time of formation of the coating layer, or to prevent a film having a coating layer due to hardening shrinkage at the time of formation of the coating layer. Further, since the protective sheet itself is excellent in smoothness and has rigidity, it prevents the defects caused by the protective sheet (for example, the fine unevenness of the surface of the protective sheet is transferred to the film, and the protective sheet is shrunk. The unevenness is transferred to the above-mentioned film and the like. Further, the upper limit of the stiffness of the protective sheet is preferably 100 mm. If it is such a range, a coating layer can be formed without a defect, such as a warpage. The protective sheet is preferably formed so as to have an adhesive force to the film of 0.01 N/25 mm to 1.00 N/25 mm, more preferably 0.1 N/25 mm to 0.5 N/25 mm. When a protective sheet having such an adhesive force is used, wrinkles can be prevented from occurring at the time of formation of the coating layer, and the protective sheet can be easily peeled off after the formation of the coating layer. In the present specification, the adhesive force is determined by the method according to JIS Z 0237 (2000) (measurement temperature: 23 ° C, bonding conditions: one-time roll of 2 kg roller, peeling speed: 300 mm/min, peeling angle of 180°) The measurement was carried out. In one embodiment, the protective sheet includes a substrate and an adhesive layer formed on the substrate. In the step of laminating the protective sheet, the side of the adhesive layer of the protective sheet is bonded to the above film. Further, in the protective sheet comprising the substrate and the adhesive layer, the arithmetic surface roughness Ra corresponds to the arithmetic surface roughness Ra of the surface of the substrate opposite to the adhesive layer. As the material constituting the above substrate, any suitable material can be used as long as the effects of the present invention can be obtained. Examples of the material constituting the substrate include polyethylene terephthalate, polyethylene, polypropylene, and polyolefin. Among them, polyethylene terephthalate is preferred. If polyethylene terephthalate is used, a substrate having a relatively small thickness and a high stiffness can be obtained (finally obtaining a protective sheet). The thickness of the substrate is preferably from 10 μm to 100 μm, more preferably from 15 μm to 80 μm, still more preferably from 20 μm to 50 μm. The above adhesive layer is composed of any suitable adhesive. Specific examples of the pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive, a polyethylene-based pressure-sensitive adhesive, a polypropylene-based pressure-sensitive adhesive, and a polyolefin-based pressure-sensitive adhesive. The thickness of the above adhesive layer is preferably 10 μm or less, more preferably 8 μm or less. By setting it as such a range, generation of wrinkles at the time of formation of a coating layer becomes few. Further, warpage of the film with the coating layer can be suppressed. The lower limit of the thickness of the adhesive layer is, for example, 1 μm. <Formation of Coating Layer> As described above, after the sheet is protected by one of the film layers, a coating layer is formed on the other side of the film. The coating layer forming step typically includes coating of a coating layer forming composition, heating of a coating layer, and the like. In one embodiment, the coating layer is made of a curable resin. In this case, the coating layer may be further subjected to a hardening treatment (for example, ultraviolet irradiation or heating) in the coating layer forming step. The manufacturing method of the present invention is particularly useful for the formation of a coating layer to be hardened. Previously, the hardening shrinkage of the curable resin caused by the hardening treatment is larger than the shrinkage when the coating layer is formed by drying, which is a large cause of wrinkles in the film, according to the present invention, even when the curable resin is hardened and shrunk. It is also possible to obtain a film with a coating layer in the case of preventing wrinkles from occurring. As the curable resin, a photocurable resin (for example, an ultraviolet curable resin) or a thermosetting resin can be used. Among them, a photocurable resin is preferred. The curing shrinkage at the time of curing the photocurable resin is large. Therefore, the present invention is particularly useful as a method of forming a coating layer made of a photocurable resin. Further, after the coating layer is formed, the coating layer may be subjected to a surface treatment such as corona treatment or plasma treatment. Specific examples of the coating layer include a hard coat layer, an antiglare layer, an anti-blocking layer, an antireflection layer, and a conductive layer. Among them, the manufacturing method of the present invention is particularly useful in the case of forming a hard coat layer or an antiglare layer. The coating layer-forming composition contains any suitable resin material (monomer, oligomer, prepolymer, and/or polymer). In one embodiment, the composition for forming a coating layer contains a thermosetting type or a photocurable type of curable compound as a resin material. When a composition for forming a coating layer containing a curable compound is used, for example, a hard coat layer or an antiglare layer can be formed. The curable compound may be any of a monomer, an oligomer, and a prepolymer. As the curable compound, a polyfunctional monomer or oligomer can be used, and examples thereof include a monomer or oligomer having two or more (meth)acryl fluorenyl groups, and a (meth)acrylic acid urethane. Or an oligomer of (meth)acrylic acid urethane, an epoxy monomer or oligomer, a polyoxynitride monomer or an oligomer. The coating layer forming composition may further comprise any suitable additive. Examples of the additive include a polymerization initiator, a leveling agent, an anti-blocking agent, a dispersion stabilizer, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a tackifier, a dispersing agent, and a surfactant. , catalyst, filler, lubricant, antistatic agent, etc. The kind, combination, content, and the like of the additive to be contained may be appropriately set depending on the purpose or desired characteristics. In one embodiment, the composition for forming a coating layer contains fine particles as an additive. When the composition for forming a coating layer containing fine particles is used, an antiglare layer can be formed. The microparticles may be inorganic microparticles or organic microparticles. Examples of the inorganic fine particles include cerium oxide fine particles, titanium oxide fine particles, alumina fine particles, zinc oxide fine particles, tin oxide fine particles, calcium carbonate fine particles, barium sulfate fine particles, talc fine particles, kaolin fine particles, and calcium sulfate fine particles. Examples of the organic fine particles include polymethyl methacrylate resin powder (PMMA fine particles), polyoxynoxy resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, and benzoguanamine resin. Powder, melamine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimine resin powder, polyvinyl fluoride resin powder, and the like. These fine particles may be used singly or in combination of plural kinds. The composition for forming a coating layer may or may not contain a solvent. Examples of the solvent include dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, and 1,3-dioxane. Cyclopentane, 1,3,5-trioxane, tetrahydrofuran, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone (CPN), Cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, n-amyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n-amyl acetate, acetamidine, Diacetone alcohol, ethyl acetate methyl acetate, ethyl acetate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-methyl- 2-butanol, cyclohexanol, isopropanol (IPA), isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, 2-heptanone , 3-heptanone, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and the like. These may be used alone or in combination of plural kinds. As a coating method of the composition for forming a coating layer, any appropriate method can be employed. For example, a bar coating method, a gravure roll coating method, a die coating method, a bar coating method, a slit coating method, a curtain coating method, a spray coating method, Scraper coating method. Further, in the present invention using a thinner and less plastic film, if a gravure roll coating method is employed, the coating layer can be formed with better thickness precision. The heating temperature of the coating layer of the coating layer-forming composition can be set to a suitable temperature depending on the composition of the coating layer-forming composition, and is preferably set to be equal to or lower than the glass transition temperature of the resin contained in the film. When the film is heated at a temperature lower than the glass transition temperature of the resin contained in the film, a film with a coating layer which is suppressed by deformation due to heating can be obtained. The heating temperature is, for example, 60 ° C to 140 ° C, preferably 60 ° C to 100 ° C. By heating in such a range, a coating layer excellent in adhesion to a film can be formed. As the hardening treatment, any suitable hardening treatment can be employed. Typically, the hardening treatment is performed by ultraviolet irradiation. The cumulative amount of light by ultraviolet irradiation is preferably from 200 mJ to 400 mJ. The thickness of the coating layer is preferably 10 μm or less, more preferably 2 μm to 6 μm. When it is such a range, it is possible to obtain a film with a coating layer which can be sufficiently exhibited as a coating layer and which is excellent in appearance. In one embodiment, the pencil hardness of the coating layer is preferably H or more, more preferably 3H or more. If it is such a range, a coating layer can function effectively as a hard-coat layer. The pencil hardness can be measured in accordance with the pencil hardness test of JIS K 5400. [Examples] Hereinafter, the present invention will be specifically described by way of Examples, but the present invention is not limited to the Examples. The evaluation methods in the examples are as follows. Further, in the examples, "parts" and "%" are based on weight unless otherwise specified. (1) The stiffness was measured in accordance with JIS L1096 (45°, cantilever method). Specifically, as shown in FIG. 2, on the upper surface (horizontal plane) of the trapezoidal and smooth mold B having a slope of 45°, the one end a of the test piece A is located at the side b of the slope side of the mold horizontal plane. The test piece A (size: 20 mm × 150 mm) was placed, and the test piece A was gently slid on the side of the inclined surface, and the horizontal movement distance L of the test piece when the end a of the test piece was in contact with the lower side of the inclined surface was measured. With respect to the protective sheet, the moving distance L was measured by the above operation using the adhesive layer as the upper side, and the measured value was taken as the stiffness of the protective sheet. For the film with the coating layer (hard coating layer), the average of the moving distance measured with the coating layer side up and the moving distance measured with the coating layer facing downward as the coating layer The stiffness of the film. (2) Arithmetic surface roughness Ra The arithmetic surface roughness Ra of the substrate constituting the protective sheet was measured by the following method. The glass plate (thickness 1.3 μm) manufactured by MATSUNAMI Co., Ltd. was attached to the surface opposite to the measurement surface, and the surface shape was measured using a three-dimensional optical profile analyzer New View 7300 (manufactured by ZYGO Co., Ltd.). Based on the measured data, the arithmetic surface roughness Ra was calculated in accordance with JIS B 0601-2001. (3) Appearance The appearance of the film with the coating layer obtained was visually confirmed. The evaluation criteria are as follows. AA: No wrinkle generation A: There are few wrinkles that can be visually recognized, and it is practically possible to allow B: wrinkles which are visible as unevenness, and practically allow C: to be practical In the case of the composition of the hard coat layer, the urethane urethane resin (manufactured by DIC Corporation, product name "UNIDIC 17-806"), 100 parts, and a leveling agent ( One part of the product name "GRANDIC PC4100" manufactured by DIC Corporation, and a photopolymerization initiator (manufactured by Ciba Japan Co., Ltd., trade name: Irgacure 907) were mixed in three portions, and the cyclopentane was used in such a manner that the solid content concentration was 40%. The ketone is diluted to prepare a composition for forming a hard coat layer. <Example 1> The sheet A was protected by an area layer of a polycarbonate film (thickness: 20 μm, stiffness: 35 mm). As the protective sheet A, a protective sheet A (manufactured by SUN A. KAKEN Co., Ltd., having an adhesive layer (thickness: 5 μm) on one side of a PET substrate (surface roughness Ra: 0.02 μm), trade name "NSA32T"", thickness: 25 μm). The sheet A has a stiffness of 45 mm. Then, the polycarbonate-based film was transferred, and the composition for forming a hard coat layer prepared in Production Example 1 was applied to the other surface of the film, and heated at 75 °C. The coating layer after heating was irradiated with ultraviolet rays having a cumulative light amount of 300 mJ/cm ² by a high-pressure mercury lamp to harden the coating layer to form a hard coat layer (thickness: 2 μm). Furthermore, in this step, the film was smoothly conveyed without causing a problem. A film with a coating layer (hard coat layer) was thus obtained. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. <Example 2> A coating film with a coating layer was obtained in the same manner as in Example 1 except that the coating amount of the composition for forming a hard coat layer was adjusted so that the thickness of the hard coat layer was 6 μm. . The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. Further, in the hard coat layer forming step, the film was smoothly conveyed without causing a problem. <Example 3> The sheet B was protected by an area layer of a polycarbonate film (thickness: 20 μm, stiffness: 35 mm). As the protective sheet B, a protective sheet B (manufactured by Nitto Denko Corporation, trade name "HP300") having an adhesive layer (thickness: 5 μm) on one side of a PET substrate (surface roughness Ra: 0.05 μm) is used. Thickness: 38 μm). The sheet B has a stiffness of 60 mm. A hard coat layer was formed on the other side of the polycarbonate film by the same manner as in Example 1. Furthermore, in this step, the film was smoothly conveyed without causing a problem. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. <Example 4> The sheet C was protected by an area layer of a polycarbonate film (thickness: 20 μm, stiffness: 35 mm). As the protective sheet C, a protective sheet C (manufactured by Nitto Denko Corporation, trade name "RP300") having an adhesive layer (thickness: 23 μm) on one side of a PET substrate (surface roughness Ra: 0.05 μm) is used. Thickness: 38 μm). The stiffness of the protective sheet C is 60 mm. A hard coat layer was formed in the same manner as in Example 1 on the other side of the unstretched polycarbonate film. Furthermore, in this step, the film was smoothly conveyed without causing a problem. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. <Example 5> A polycarbonate film (thickness: 15 μm, stiffness: 25 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm), except A film with a coating layer was obtained in the same manner as in Example 1. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. Further, in the hard coat layer forming step, the film was smoothly conveyed without causing a problem. <Example 6> A cycloolefin film (thickness: 25 μm, stiffness: 38 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm), and A film with a coating layer was obtained in the same manner as in Example 1. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. Further, in the hard coat layer forming step, the film was smoothly conveyed without causing a problem. <Comparative Example 1> The sheet D was protected by an area layer of a polycarbonate film (thickness: 20 μm, stiffness: 35 mm). As the protective sheet D, a protective sheet D (having a thickness of 3 μm) having a single adhesive layer (thickness: 3 μm) on a single side of a polyethylene substrate (manufactured by Toray Co., Ltd., trade name "TORETEC 7832C- 30", thickness: 28 μm). The stiffness of the protective sheet D is 30 mm. A hard coat layer was formed in the same manner as in Example 1 on the other side of the unstretched polycarbonate film. Further, in this step, it was confirmed that the film was bent (not broken). The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. <Comparative Example 2> A cycloolefin film (thickness: 25 μm, stiffness: 38 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm), and Comparative Example 1 obtained a film with a coating layer in the same manner. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. Further, in the hard coat layer forming step, it was confirmed that the film was bent (unbroken). <Reference Example 1> The composition for forming a hard coat layer prepared in Production Example 1 was applied to one surface of a polycarbonate film (thickness: 40 μm, stiffness: 45 mm), and heated at 75 °C. The coating layer after heating was irradiated with ultraviolet rays having a cumulative light amount of 300 mJ/cm ² by a high-pressure mercury lamp to harden the coating layer to form a hard coat layer (thickness: 2 μm). Furthermore, in this step, the film was smoothly conveyed without causing a problem. A film with a coating layer (hard coat layer) was thus obtained. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. <Reference Example 2> A polycarbonate film (thickness: 40 μm, stiffness: 45 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm), except A film with a coating layer was obtained in the same manner as in Example 1. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. Further, in the hard coat layer forming step, the film was smoothly conveyed without causing a problem. <Reference Example 3> A polycarbonate film (thickness: 40 μm, stiffness: 45 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm), and the hard coat layer was used. A film with a coating layer was obtained in the same manner as in Comparative Example 1, except that the thickness was 2 μm. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. Further, in the hard coat layer forming step, the film was smoothly conveyed without causing a problem. <Reference Example 4> The composition for forming a hard coat layer prepared in Production Example 1 was applied to one surface of a polycarbonate film (thickness: 20 μm, stiffness: 35 mm), and heated at 75 °C. The coating layer after heating was irradiated with ultraviolet rays having a cumulative light amount of 300 mJ/cm ² by a high-pressure mercury lamp to harden the coating layer to form a hard coat layer (thickness: 2 μm). Further, in this step, it was confirmed that the film was broken. A film with a coating layer (hard coat layer) was thus obtained. The obtained film with the coating layer was supplied to the above evaluation (3). The results are shown in Table 1. [Table 1] As is apparent from Table 1, according to the production method of the present invention, the coating layer can be formed on the thin film without wrinkles or the like. More specifically, when the coating layer is formed on a thin film by the prior art, there is a problem in conveyability (Reference Example 4), but a protective sheet which is appropriately adjusted by using the surface roughness Ra and the stiffness is used ( In Examples 1 to 6), it was possible to suppress generation of wrinkles to the same extent as in the case where a coating layer was formed on a film having a thick thickness and a straight thickness (Reference Example 1). [Industrial Applicability] The film with a coating layer obtained by the production method of the present invention can be preferably used for an image display device.

10‧‧‧coating layer

20‧‧‧ film

30‧‧‧Protected sheet

A‧‧‧ one end of the test piece

A‧‧‧ test piece

B‧‧•Slope side end of the mould water level

B‧‧‧

Horizontal movement distance of L‧‧‧ test piece

1(a) to 1(c) are views showing a manufacturing method of the present invention in an embodiment of the present invention. Fig. 2 is a view for explaining a method of measuring stiffness.

Claims (9)

A manufacturing method of a film with a coating layer, comprising: one surface layer protective sheet of a film having a thickness of 25 μm or less and a stiffness of 40 mm or less; and a coating layer formed on the other side of the film; Further, the arithmetic mean surface Ra of the surface of the protective sheet opposite to the film is 0.1 μm or less, and the protective sheet has a stiffness of 40 mm or more. The method for producing a film with a coating layer according to claim 1, wherein the protective sheet comprises a substrate and an adhesive layer formed on the substrate, and the adhesive side of the protective sheet is attached to the above film. A method of producing a film of a coating layer according to claim 2, wherein the thickness of the adhesive layer is 10 μm or less. A method of producing a film of a coating layer according to claim 2 or 3, wherein said protective sheet is releasably laminated to said film. The method for producing a film with a coating layer according to any one of claims 1 to 4, wherein the film is an optical film. The method for producing a film having a coating layer according to any one of claims 1 to 5, wherein the coating layer is made of a curable resin. A method for producing a film of a coating layer according to claim 6, wherein the curable resin is photocurable. A method for producing a film of a coating layer according to claim 6, wherein the curable resin is thermosetting. The method for producing a film with a coating layer according to any one of claims 1 to 8, wherein the coating layer has a thickness of 4 μm or less.