JP2018083327A - Production method of film with coating layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a film with a coating layer in which a coating layer is formed on a thin film, capable of producing a film with a coating layer without occurrence of wrinkles or the like.SOLUTION: A production method of a film 20 with a coating layer 10 comprises: a step for laminating a protection sheet 30 on one surface of the film 20 whose thickness is 25 μm or less, and rigidity/flexibility is 40 mm or less; and a step for forming the coating layer 10 on the other surface of the film, in which an arithmetic mean surface roughness Ra of a surface opposite to the film of the protection sheet 30 is 0.1 μm or less, and rigidity/flexibility of the protection sheet 30 is 40 mm or more. In the production method of the film 20 with the coating layer 10, the protection sheet 30 has a base material layer and an adhesive layer formed on the base material, and the adhesive layer side of the protection sheet is stuck to the film 20, and thickness of the adhesive layer is 10 μm or less.SELECTED DRAWING: Figure 1

Description

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

  Generally, a coating layer capable of performing 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 from the outside and an antiglare layer for improving antiglare properties are provided. Conventionally, such a coating layer is provided by laminating a surface film (for example, a hard coat film or an antiglare film) composed of a coating layer and a base material on a member of an image display device.

  On the other hand, in recent years, image display devices have been made thinner, and accordingly, it has been considered to reduce the thickness of the base material constituting the surface film, or to form a coating layer directly on the thin optical film. It is being considered. 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, at the time of hard coat layer curing treatment), resulting in poor appearance and poor optical characteristics. . Further, when forming the coating layer, a method of supporting the optical film with a protective sheet is conceivable, but when this method is adopted, the protective sheet is uneven when heated in the coating layer forming step, and the unevenness is The problem of being transferred to an optical film arises. Under such circumstances, establishment of a technique capable of forming a coating layer without generation of wrinkles is required even when a thin film is used.

Japanese Patent Laid-Open No. 2006-68497

  The present invention has been made in order to solve the above-described conventional problems, and an object of the present invention is a method for producing a film with a coating layer in which a coating layer is formed on a thin film, and there is no occurrence of wrinkles or the like. It is providing the manufacturing method which can manufacture a film with a coating layer.

The method for producing a film with a coating layer according to the present invention comprises laminating a protective sheet on one surface of a film having a thickness of 25 μm or less and a bending resistance of 40 mm or less, and the other surface of the film And forming a coating layer, the arithmetic average surface roughness Ra of the surface of the protective sheet opposite to the film is 0.1 μm or less, and the stiffness of the protective sheet is 40 mm or more .
In one embodiment, the protective sheet includes a base material and a pressure-sensitive adhesive layer formed on the base material, and the pressure-sensitive adhesive side of the protective sheet is bonded to the film.
In one embodiment, the thickness of the said adhesive layer is 10 micrometers or less.
In one embodiment, the protective sheet is laminated so as to be peelable from the film.
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 said coating layer is 4 micrometers or less.

  According to the present invention, wrinkles are prevented from occurring by forming a coating layer on the film while supporting the film with a protective sheet having a specific surface roughness Ra and stiffness, and a film with a coating layer Can be manufactured.

It is a figure explaining the manufacturing method of the present invention by one embodiment of the present invention. It is a figure explaining the measuring method of bending resistance.

  Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.

  FIG. 1 is a diagram for explaining a manufacturing method of the present invention according to one embodiment of the present invention. The manufacturing method of the film with a coating layer of this invention is a method of forming the coating layer 10 in the thin film 20, Comprising: The protective sheet 30 is laminated | stacked on one surface of the thin film 20 (FIG. 1 (a )), And forming the coating layer 10 on the other surface of the film 20 (the surface opposite to the surface on which the protective sheet 30 is laminated) (FIG. 1B). In one embodiment, protection sheet 30 is laminated so that exfoliation to film 20 is possible. In one embodiment, after forming the coating layer 10 and obtaining a film with a coating layer, the protective sheet 30 is peeled off (FIG. 1C).

  The film has a thickness of 25 μm or less. In the present invention, even if a film having a small thickness and easily wrinkles is used conventionally, the generation of wrinkles can be prevented and the coating layer can be formed. The thickness of the film can be appropriately set depending on the application. In one embodiment, the thickness of the film is 20 μm or less. In another embodiment, the thickness of the film is 15 μm or less. The lower limit of the film thickness is, for example, 1 μm.

  The bending resistance of the film is 40 mm or less. According to the present invention, it is possible to prevent the generation of wrinkles and form a coating layer even when using a film that has low bending resistance (that is, has no stiffness) and is difficult to avoid the generation of wrinkles in the conventional method. In one embodiment, a film having a stiffness of 5 mm to 35 mm may be used. In another embodiment, a film having a stiffness of 5 mm to 25 mm may be used. In this specification, the bending resistance is measured according to JIS L1096 (45 °, cantilever method). A detailed measurement method will be described later.

  The film is preferably light transmissive. In one embodiment, the light transmittance of the film is 40% or more, preferably 45% to 50%. In another embodiment, the light transmittance of the film is 70% or more, more preferably 80% or more, and 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 (polarizer, or a polarizing plate composed of a polarizer and a protective film), a brightness enhancement film, a light diffusion film, a light collecting film, and the like.

  Any appropriate material can be adopted as the material constituting the film. Examples thereof include polycarbonate resin, polyvinyl acetal resin, cycloolefin resin, acrylic resin, cellulose ester resin, cellulose resin, polyester resin, polyester carbonate resin, olefin resin, polyurethane resin, and the like. Preferably, a resin that can be a material of an optical film such as a polycarbonate resin, a polyvinyl acetal resin, a cellulose ester resin, a polyester resin, a polyester carbonate resin; a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, ethylene / vinyl acetate Examples thereof include hydrophilic polymer films (films used as polarizer materials) such as partially saponified copolymer films. The film may have a laminated structure composed of a plurality of layers.

<Lamination of protective sheets>
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 arithmetic surface roughness Ra of the protective sheet is preferably as small as possible, but the lower limit is, for example, 0.01 μm. In the present specification, the arithmetic surface roughness Ra is measured according to JIS B0601.

  The bending resistance of the protective sheet is 40 mm or more, preferably 45 mm or more, more preferably 50 mm or more, and further 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 stiffness and softness is used, and the film is supported by the protective sheet, thereby generating wrinkles when forming the coating layer. Can be suppressed. More specifically, film shrinkage due to heating during the formation of the coating layer can be prevented, and films with a coating layer due to curing shrinkage during the formation of the coating layer can be prevented. In addition, since the protective sheet itself is excellent in smoothness and rigid and soft, defects caused by the protective sheet (for example, the fine irregularities on the surface of the protective sheet are transferred to the film, and the protective sheet is contracted and generated. Inconveniences such as unevenness being transferred to the film are prevented. In addition, the upper limit of the bending resistance of the protective sheet is preferably 100 mm. If it is such a range, a coating layer can be formed without problems, such as curvature.

  The protective sheet is preferably configured such that the adhesive strength to the film is 0.01 N / 25 mm to 1.00 N / 25 mm, and is configured to be 0.1 N / 25 mm to 0.5 N / 25 mm. More preferably. If a protective sheet having such an adhesive force is used, the generation of wrinkles can be prevented when the coating layer is formed, and the protective sheet can be easily peeled after the coating layer is formed. In this specification, the adhesive strength is measured by a method according to JIS Z 0237 (2000) (measurement temperature: 23 ° C., bonding condition: 2 kg roller reciprocation, peeling speed: 300 mm / min, peeling angle 180 °). The

  In one embodiment, the protective sheet includes a base material and an adhesive layer formed on the base material. In the protective sheet laminating step, the pressure-sensitive adhesive layer side of the protective sheet is bonded to the film. In the protective sheet including the base material and the pressure-sensitive adhesive layer, the arithmetic surface roughness Ra corresponds to the arithmetic surface roughness Ra of the surface of the base material opposite to the pressure-sensitive adhesive layer.

  Any appropriate material can be used as the material constituting the substrate as long as the effects of the present invention can be obtained. Examples of the material constituting the base material include polyethylene terephthalate, polyethylene, polypropylene, and polyolefin. Of these, polyethylene terephthalate is preferable. If polyethylene terephthalate is used, it is possible to obtain a base material (as a result, a protective sheet) that is thin but has high bending resistance.

  The thickness of the substrate is preferably 10 μm to 100 μm, more preferably 15 μm to 80 μm, and still more preferably 20 μm to 50 μm.

  The said adhesive layer is comprised from arbitrary appropriate adhesives. Specific examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesive, polyethylene pressure sensitive adhesive, polypropylene pressure sensitive adhesive, and polyolefin pressure sensitive adhesive.

  The thickness of the pressure-sensitive adhesive layer is preferably 10 μm or less, more preferably 8 μm or less. By setting it as such a range, generation | occurrence | production of a wrinkle at the time of coating layer formation becomes less. Moreover, the curvature of the film with a coating layer can be suppressed. The minimum of the thickness of an adhesive layer is 1 micrometer, for example.

<Formation of coating layer>
After laminating a protective sheet on one side of the film as described above, a coating layer is formed on the other side of the film. This coating layer forming step typically includes application of the coating layer forming composition, heating of the coating layer, and the like. In one embodiment, the coating layer is composed of a curable resin. In this case, in the coating layer forming step, the coating layer may be further cured (for example, irradiated with ultraviolet rays or heated). The production method of the present invention is particularly useful for forming a coating layer that requires a curing treatment. Conventionally, the curing shrinkage of the curable resin by the curing process is larger than the shrinkage when forming the coating layer by drying, which is a major cause of wrinkling in the film. Even when curing shrinkage of the functional resin occurs, generation of wrinkles can be prevented and a film with a coating layer can be obtained. As the curable resin, a photocurable resin (for example, an ultraviolet curable resin) or a thermosetting resin can be used. Among these, a photocurable resin is preferable. Since the curing shrinkage when curing the photocurable resin is large, the present invention is particularly useful as a method for forming a coating layer composed of the photocurable resin. In addition, after forming a coating layer, you may perform surface treatments, such as a corona treatment and a plasma treatment, to this coating layer.

  Specific examples of the coating layer include a hard coat layer, an antiglare layer, an antiblocking layer, an antireflection layer, and a conductive layer. Especially, the manufacturing method of this invention is especially useful when forming a hard-coat layer or an anti-glare layer.

  The composition for forming a coating layer contains any appropriate resin material (monomer, oligomer, prepolymer and / or polymer). In one embodiment, the composition for forming a coating layer includes a thermosetting or photocurable curable compound as a resin material. If the 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, for example, a monomer or oligomer having two or more (meth) acryloyl groups, an oligomer of urethane (meth) acrylate or urethane (meth) acrylate, an epoxy monomer. Or an oligomer, a silicone-type monomer, an oligomer, etc. are mentioned.

  The composition for forming a coating layer may further contain any appropriate additive. Examples of the additive include a polymerization initiator, a leveling agent, an antiblocking agent, a dispersion stabilizer, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a dispersing agent, a surfactant, and a catalyst. , Fillers, lubricants, antistatic agents and the like. The kind, combination, content, and the like of the additive to be contained can be appropriately set according to the purpose and desired characteristics.

  In one embodiment, the composition for forming a coating layer contains fine particles as an additive. If a composition for forming a coating layer containing fine particles is used, an antiglare layer can be formed. The fine particles may be inorganic fine particles or organic fine particles. Examples of the inorganic fine particles include silicon oxide fine particles, titanium oxide fine particles, aluminum oxide 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), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, and polyester resin powder. , Polyamide resin powder, polyimide resin powder, polyfluorinated ethylene resin powder, and the like. These fine particles may be used alone or in combination.

  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, 1,3-dioxolane, 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-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, ethyl acetate n -Pentyl, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pen Nord, 2-methyl-2-butanol, cyclohexanol, isopropyl alcohol (IPA), isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, 2-heptanone, 3-heptanone, ethylene Examples include glycol monoethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether. These may be used alone or in combination.

  Any appropriate method can be adopted as a method for applying the composition for forming a coating layer. Examples thereof include a bar coating method, a gravure roll coating method, a die coating method, a rod coating method, a slot orifice coating method, a curtain coating method, a fountain coating method, and a comma coating method. In the present invention using a thin and weak film, if a gravure roll coating method is used, a coating layer can be formed with higher thickness accuracy.

  The heating temperature of the coating layer of the composition for forming a coating layer can be set to an appropriate temperature according to the composition of the composition for forming a coating layer, and is preferably set to be equal to or lower than the glass transition temperature of the resin contained in the film. Is done. If it heats at the temperature below the glass transition temperature of resin contained in the said film, the film with a coating layer in which the deformation | transformation by heating was suppressed can be obtained. The heating temperature is, for example, 60 ° C to 140 ° C, and preferably 60 ° C to 100 ° C. By heating in such a range, the coating layer excellent in adhesiveness with a film can be formed.

  Any appropriate curing process can be adopted as the curing process. Typically, the curing process is performed by ultraviolet irradiation. The integrated light quantity of ultraviolet irradiation is preferably 200 mJ to 400 mJ.

  The thickness of the coating layer is preferably 10 μm or less, more preferably 2 μm to 6 μm. If it is such a range, the function as a coating layer can fully be exhibited, and the film with a coating layer which is excellent in an external appearance can be obtained.

  In one embodiment, the pencil hardness of the coating layer is preferably H or higher, more preferably 3H or higher. If it is such a range, a coating layer can function effectively as a hard-coat layer. The pencil hardness can be measured according to the pencil hardness test of JIS K 5400.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The evaluation methods in the examples are as follows. In Examples, unless otherwise specified, “parts” and “%” are based on weight.

(1) Bending and softening Measured according to JIS L1096 (45 °, cantilever method). Specifically, as shown in FIG. 2, on the upper surface (horizontal surface) of a trapezoidal smooth die B having an inclined surface with an inclination angle of 45 °, one end a of the test piece A is the inclined surface side end b of the die horizontal surface. The test piece A (size: 20 mm × 150 mm) was placed so as to be positioned at the position of the test piece A, and the test piece A was gently slid to the slope side, and when the one end a of the test piece was in contact with the lower side of the slope, The horizontal movement distance L was measured. With respect to the protective sheet, with the pressure-sensitive adhesive layer on the upper side, the movement distance L was measured by the above-described operation, and the measured value was defined as the stiffness of the protective sheet. For a film with a coating layer (hard coat layer), the average value of the movement distance measured with the coating layer side up and the movement distance measured with the coating layer down was taken as the stiffness of the film with the coating layer. .

(2) Arithmetic surface roughness Ra
The arithmetic surface roughness Ra of the base material constituting the protective sheet was measured by the following method.
A glass plate (thickness 1.3 μm) manufactured by MATSANAMI was bonded to the surface opposite to the measurement surface with an adhesive, and the surface shape was measured using a three-dimensional optical profiler NewView 7300 (manufactured by ZYGO). The arithmetic surface roughness Ra was calculated from the measured data according to JIS B 0601-2001.

(3) Appearance The appearance of the obtained film with a coating layer was visually confirmed. The evaluation criteria are as follows.
A: No generation of wrinkles A: Generation of wrinkles to the extent that they can be seen only slightly, and is acceptable for practical use B: Generation of wrinkles to the extent that irregularities are visible, is acceptable for practical use C : Unevenness that is unacceptable for practical use

<Production Example 1> Preparation of hard coat layer forming composition 100 parts of urethane acrylate resin (manufactured by DIC, product name “Unidic 17-806”) and leveling agent (manufactured by DIC, product name “GRANDIC PC4100”) 1 Part, a photopolymerization initiator (Ciba Japan Co., Ltd., trade name: Irgacure 907) is mixed, diluted with cyclopentanone so that the solid content concentration becomes 40%, and a composition for forming a hard coat layer Adjusted.

<Example 1>
A protective sheet A was laminated on one surface of a long polycarbonate film (thickness: 20 μm, stiffness: 35 mm). As the protective sheet A, a protective sheet A (trade name “NSA32T”, manufactured by Sanei Kaken Co., Ltd.) having a pressure-sensitive adhesive layer (thickness: 5 μm) on one side of a PET substrate (surface roughness Ra: 0.02 μm), thickness: 25 μm) was used. The bending resistance of the protective sheet A was 45 mm.
Next, while conveying the polycarbonate film, the hard coat layer forming composition prepared in Production Example 1 was applied to the other surface of the film and heated at 75 ° C. A hard coat layer (thickness: 2 μm) was formed by irradiating the heated coating layer with ultraviolet light having an integrated light quantity of 300 mJ / cm ² by a high-pressure mercury lamp to cure the coating layer. In addition, in the said process, the film was able to be conveyed without a problem.
In this way, a film with a coating layer (hard coat layer) was obtained. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1.

<Example 2>
A 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 a coating layer was subjected to the evaluation (3). The results are shown in Table 1. In the hard coat layer forming step, the film could be transported without problems.

<Example 3>
A protective sheet B was laminated on one surface 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”, thickness: 38 μm) provided with a pressure-sensitive adhesive layer (thickness: 5 μm) on one side of a PET base material (surface roughness Ra: 0.05 μm). ) Was used. The bending resistance of the protective sheet B was 60 mm.
A hard coat layer was formed on the other surface of the polycarbonate film in the same manner as in Example 1. In addition, in the said process, the film was able to be conveyed without a problem.
The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1.

<Example 4>
A protective sheet C was laminated on one surface 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”, thickness: 38 μm) provided with a pressure-sensitive adhesive layer (thickness: 23 μm) on one side of a PET base material (surface roughness Ra: 0.05 μm). ) Was used. The bending resistance of the protective sheet C was 60 mm.
A hard coat layer was formed in the same manner as in Example 1 on the other surface of the unstretched polycarbonate film. In addition, in the said process, the film was able to be conveyed without a problem.
The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1.

<Example 5>
A film with a coating layer was prepared in the same manner as in Example 1 except that a polycarbonate film (thickness: 15 μm, stiffness: 25 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm). Obtained. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1. In the hard coat layer forming step, the film could be transported without problems.

<Example 6>
A film with a coating layer in the same manner as in Example 1 except that a cycloolefin film (thickness: 25 μm, stiffness: 38 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm). Got. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1. In the hard coat layer forming step, the film could be transported without problems.

<Comparative Example 1>
A protective sheet D was laminated on one surface of a polycarbonate film (thickness: 20 μm, stiffness: 35 mm). As the protective sheet D, a protective sheet D (manufactured by Toray Industries, trade name “Tretec 7832C-30”) having a pressure-sensitive adhesive layer (thickness: 3 μm) on one side of a polyethylene substrate (surface roughness Ra: 0.2 μm), thickness : 28 μm). The bending resistance of the protective sheet D was 30 mm.
A hard coat layer was formed in the same manner as in Example 1 on the other surface of the unstretched polycarbonate film. In this process, the film was confirmed to be broken (no breakage).
The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1.

<Comparative example 2>
A film with a coating layer in the same manner as in Comparative Example 1, except that a cycloolefin film (thickness: 25 μm, stiffness: 38 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm) Got. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1. In the hard coat layer forming step, the film was confirmed to be broken (no breakage).

<Reference Example 1>
The hard coat layer forming composition 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. A hard coat layer (thickness: 2 μm) was formed by irradiating the heated coating layer with ultraviolet light having an integrated light quantity of 300 mJ / cm ² by a high-pressure mercury lamp to cure the coating layer. In addition, in the said process, the film was able to be conveyed without a problem.
In this way, a film with a coating layer (hard coat layer) was obtained. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1.

<Reference Example 2>
A film with a coating layer was prepared in the same manner as in Example 1 except that a polycarbonate film (thickness: 40 μm, stiffness: 45 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm). Obtained. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1. In the hard coat layer forming step, the film could be transported without problems.

<Reference Example 3>
Comparative Example 1 except that the polycarbonate film (thickness: 40 μm, stiffness: 45 mm) was used instead of the polycarbonate film (thickness: 20 μm, stiffness: 35 mm), and the thickness of the hard coat layer was 2 μm. Similarly, a film with a coating layer was obtained. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1. In the hard coat layer forming step, the film could be transported without problems.

<Reference Example 4>
The hard coat layer forming composition 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. A hard coat layer (thickness: 2 μm) was formed by irradiating the heated coating layer with ultraviolet light having an integrated light quantity of 300 mJ / cm ² by a high-pressure mercury lamp to cure the coating layer. In addition, in the said process, the fracture | rupture of the film was confirmed.
In this way, a film with a coating layer (hard coat layer) was obtained. The obtained film with a coating layer was subjected to the evaluation (3). The results are shown in Table 1.

  As is apparent from Table 1, according to the production method of the present invention, a coating layer can be formed on a thin film without generation of wrinkles or the like. More specifically, according to the prior art, there is a problem in the transportability when a coating layer is formed on a thin film (Reference Example 4), but a protective sheet in which the surface roughness Ra and the bending resistance are appropriately adjusted is used. By using (Examples 1 to 6), the generation of wrinkles can be suppressed to the same extent as when the coating layer is formed on a thick and rigid film (Reference Example 1).

  The film with a coating layer obtained by the production method of the present invention can be suitably used for an image display device.

10 coating layer 20 film 30 protective sheet

Claims (9)

Including laminating a protective sheet on one surface of a film having a thickness of 25 μm or less and a bending resistance of 40 mm or less, and forming a coating layer on the other surface of the film;
The arithmetic average surface Ra of the surface of the protective sheet opposite to the film is 0.1 μm or less,
The bending resistance of the protective sheet is 40 mm or more,
A method for producing a film with a coating layer. The protective sheet comprises a substrate and a pressure-sensitive adhesive layer formed on the substrate,
The adhesive side of the protective sheet is bonded to the film,
The manufacturing method of the film with a coating layer of Claim 1.   The manufacturing method of the film with a coating layer of Claim 2 whose thickness of the said adhesive layer is 10 micrometers or less.   The manufacturing method of the film with a coating layer of Claim 2 or 3 with which the said protective sheet is laminated | stacked so that peeling with respect to the said film is possible.   The manufacturing method of the film with a coating layer in any one of Claim 1 to 4 whose said film is an optical film.   The manufacturing method of the film with a coating layer in any one of Claim 1 to 5 with which the said coating layer is comprised from curable resin.   The manufacturing method of the film with a coating layer of Claim 6 whose said curable resin is photocurable.   The manufacturing method of the film with a coating layer of Claim 6 whose said curable resin is thermosetting. The manufacturing method of the film with a coating layer in any one of Claim 1 to 8 whose thickness of the said coating layer is 4 micrometers or less.

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