Film and method for producing same

Abstract

The surface of the thin film has valleys and peaks based on JIS B0601: 2001, and the maximum valley depth (Rv) of the valleys, the maximum peak height (Rp) of the peaks, and the average width (RSm) of the contour units based on JIS B0601: 2001 satisfy the following conditions: 1.50 [mu] mlt; rvlt; the thickness is 8.00 mu m, and the thickness is 0.80 lt; rv / (Rv + Rp) lt; 0.90, 30 [mu] mlt; rSmlt, RSmlt; the thickness of the film is 300 [mu] m, the storage modulus of the film is 0.052-1.500 GPa, and the film contains a UV-curable resin.

Description

Technical Field

[0001] The present invention relates to a thin film and a method for making the same. Background Art

[0002] In recent years, it has become popular to input information into information devices such as smartphones, notebook computers, and tablet computers via information input panels such as touch panels. In particular, pen-type touch devices such as stylus pens, such as handwriting tablets, liquid crystal tablets, tablet computers, and electronic paper, can input information, and the pen-type touch devices are used for writing texts, drawing pictures, and the like.

[0003] As pen input devices are used for various purposes, various advanced functions are required for input methods using pen-shaped touch devices. For example, if the pen-shaped touch device is used directly in the pen input device, the pen tip slips and the writing feeling is poor, so a function is required to give appropriate writing resistance to give the writing feeling of writing with a pencil on paper.

[0004] In order to provide the above-mentioned writing feeling, various films for pen input devices have been proposed.

[0005] For example, Patent Document 1 discloses a laminated film for a touch panel in which a hard coat layer contains silica fine particles and has a convex shape on the surface.

[0006] Patent Document 2 discloses a film for improving touch in which a convex shape is imparted to the surface by the shape of a resin.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent document 1: Japanese Patent Application Publication No. 2010-153298;

[0010] Patent document 2: Japanese Patent Application Laid-Open No. 2014-137640. Summary of the invention

[0011] Technical problem to be solved by the invention

[0012] However, the laminated film for a touch panel described in Patent Document 1 has a problem in that when information is input using a pen-shaped touch device, the silica particles on the hard coat layer are easily detached, and the surface of the film is easily damaged.

[0013] Furthermore, the touch-improving film described in Patent Document 2 has a problem in that when information is inputted using a pen-shaped touch device, the convex portion of the resin is easily peeled off and the surface of the film is easily damaged (ie, the scratch resistance is poor).

[0014] The present invention has been accomplished in view of such circumstances, and an object thereof is to provide a film having excellent wiping resistance, excellent writing feeling when inputting information using a pen-shaped touch device to a pen input device with a pasted film, and excellent ease of operation (bendability), and a method for manufacturing the film.

[0015] Technical means for solving technical problems

[0016] The inventors of the present invention conducted intensive studies to solve the above technical problems, and as a result, found that the above technical problems can be solved by using the following film, and thus completed the present invention. The surface of the film has valleys and peaks based on JIS B0601:2001, and the maximum valley depth (Rv) of the valleys, the maximum peak height (Rp) of the peaks, and the average width (RSm) of the profile units based on JIS B0601:2001 satisfy the following conditions: 1.50 μm < Rv < 8.00 μm, 0.80 < Rv / (Rv + Rp) < 0.90, 30 μm < RSm < 300 μm. The storage modulus of the film is 0.052 GPa to 1.500 GPa, and the film contains a UV curable resin.

[0017] That is, the present invention is as follows.

[0018] 1. A film, the surface of which has valleys and peaks based on JIS B0601:2001,

[0019] The maximum valley depth (Rv) of the valleys, the maximum peak height (Rp) of the peaks, and the average width (RSm) of the profile units based on JIS B0601:2001 satisfy the following conditions:

[0020] 1.50 μm < Rv < 8.00 μm;

[0021] 0.80 < Rv / (Rv + Rp) < 0.90;

[0022] 30 μm < RSm < 300 μm;

[0023] The storage modulus of the film is 0.052 GPa to 1.500 GPa,

[0024] The film contains a UV curable resin.

[0025] 2. The film according to 1, wherein the surface does not contain fine particles for forming the valleys and / or peaks.

[0026] 3. The film according to 1 or 2, wherein the storage modulus of the film is 0.150 GPa to 1.000 GPa.

[0027] 4. The film according to 1 or 2, wherein the UV curable resin comprises one or more selected from the group consisting of (meth)acrylate oligomers and (meth)acrylate monomers.

[0028] 5. The film according to 4, wherein the (meth)acrylate oligomer comprises one or more selected from the group consisting of urethane (meth)acrylate oligomers, acrylic resin (meth)acrylate oligomers, epoxy (meth)acrylate oligomers and polyester (meth)acrylate oligomers,

[0029] The (meth)acrylate monomer includes one or more selected from the group consisting of isobornyl (meth)acrylate monomer, tripropylene glycol di(meth)acrylate monomer, tetrahydrofurfuryl (meth)acrylate monomer, phenoxyethyl (meth)acrylate monomer, dipentaerythritol hexa(meth)acrylate monomer, tricyclodecane dimethanol di(meth)acrylate monomer, benzyl (meth)acrylate monomer, stearyl (meth)acrylate monomer, isodecyl (meth)acrylate monomer, isooctyl (meth)acrylate monomer, 1,6-hexanediol di(meth)acrylate monomer, lauryl (meth)acrylate monomer, m-phenoxybenzyl (meth)acrylate monomer, isopentyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate monomer and 1,4-butanediol di(meth)acrylate monomer.

[0030] 6. The film according to 1 or 2, further comprising a photopolymerization initiator.

[0031] 7. The film according to 1 or 2, which is a film for a pen input device.

[0032] 8. A method for manufacturing a thin film, comprising:

[0033] A coating step of coating a UV curable resin composition; and

[0034] A process of forming valleys and peaks on the film surface by transfer using a positive mold, wherein the valleys and peaks are based on JIS B0601:2001.

[0035] In the film, the maximum valley depth (Rv) of the valley, the maximum peak height (Rp) of the peak, and the average width (RSm) of the profile unit based on JIS B0601:2001 satisfy the following conditions:

[0036] 1.50μm <Rv<8.00μm;

[0037] 0.80 <Rv / (Rv+Rp)<0.90;

[0038] 30μm <RSm<300μm;

[0039] The storage modulus of the film is 0.052 GPa to 1.500 GPa,

[0040] and the film contains a UV curable resin.

[0041] Advantages of the Invention

[0042] According to the present invention, it is possible to provide a film excellent in wiping resistance, writing feeling when inputting information using a pen input device with a film pasted thereon by a pen-shaped touch device, and ease of operation (bendability), and a method for manufacturing the film. Detailed Embodiments

[0043] Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. In addition, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof. The "~" in the numerical range includes the numerical values before and after it. For example, "0 mass% to 100 mass%" means a range of 0 mass% or more and 100 mass% or less.

[0044] 1. Film

[0045] The film according to the present embodiment is a film having valleys and peaks based on JIS B0601:2001 on the surface, and the maximum valley depth (Rv) of the valleys, the maximum peak height (Rp) of the peaks, and the average width (RSm) of the profile units based on JIS B0601:2001 satisfy the following conditions: 1.50 μm < Rv < 8.00 μm, 0.80 < Rv / (Rv + Rp) < 0.90, and 30 μm < RSm < 300 μm. The storage modulus of the film is 0.052 GPa to 1.500 GPa, and the film contains a UV curable resin.

[0046] The film according to the present embodiment is not particularly limited, and for example, it is used by being pasted on substrates of various shapes (curved surfaces, flat surfaces, etc.) and various materials (glass, acrylic resin, polyoxymethylene resin, etc.).

[0047] When the film satisfies the relationships of 1.50 μm < Rv < 8.00 μm, 0.80 < Rv / (Rv + Rp) < 0.90, and 30 μm < RSm < 300 μm, there is a tendency for excellent writing feeling when inputting information using a pen-shaped touch device to a pen input device with a film pasted thereon and having wiping resistance. In addition, when the storage modulus of the film is 0.052 to 1.500 GPa, there is a tendency for excellent wiping resistance and bendability. In addition, by containing a UV curable resin, there is a tendency for excellent wiping resistance and excellent moldability.

[0048] When the film satisfies the relationships of 1.50 μm < Rv < 8.00 μm, 0.80 < Rv / (Rv + Rp) < 0.90, and 30 μm < RSm < 300 μm, the main reason for the tendency of excellent rubbing resistance is considered to be that by forming peaks based on JIS B0601:2001 on the surface of the film, the formation of large peaks can be suppressed, thereby suppressing damage to the surface of the film caused by the partial or complete loss of the film surface due to friction. In addition, when satisfying the above relationships, the main reason for the tendency of excellent writing feeling when inputting information to the pen input device with the film pasted thereon by a pen-shaped touch device is considered to be that by forming valleys based on JIS B0601:2001, the formation of valleys of appropriate size can be promoted, and when inputting information to the pen input device with the film pasted thereon by a pen-shaped touch device, an appropriate resistance is given. However, the main reasons for the tendency of excellent rubbing resistance and excellent writing feeling when inputting information to the pen input device with the film pasted thereon by a pen-shaped touch device are not limited to this.

[0049] When the storage modulus of the film is 0.052 to 1.500 GPa, it has a tendency of excellent rubbing resistance and bendability. When the storage modulus of the film is 0.052 GPa or more, the film exhibits appropriate hardness. Thereby, it is possible to suppress the surface of the film from being damaged due to partial or complete peeling of the film due to friction (that is, excellent rubbing resistance). In addition, when the storage modulus of the film is 1.500 GPa or less, the film exhibits appropriate softness. Thereby, for substrates of various shapes (curved surfaces, flat surfaces, etc.) and various materials (glass, acrylic resins, polyacetal resins, etc.), the film can be adhered without generating cracks on the surface (that is, excellent bendability). However, the main reasons for the tendency of excellent rubbing resistance and bendability are not limited to this.

[0050] The film of the present embodiment has a tendency of excellent rubbing resistance, writing feeling when inputting information to the pen input device with the film pasted thereon by a pen-shaped touch device, and bendability, and thus is suitable for use as a film for a pen input device. As the pen input device, as long as it is a display device that can input information through a pen-shaped touch device such as a stylus, it is not particularly limited, and for example, a writing board, a liquid crystal tablet, a tablet computer, an electronic paper, etc. can be cited.

[0051] Hereinafter, each component of the film (hereinafter also simply referred to as "film") of the present embodiment will be described in detail, but the present invention is not limited thereto, and various modifications can be made without departing from the gist thereof.

[0052] The film uses a UV curable resin composition as a raw material and is manufactured by the method described later. The UV curable resin composition contains a UV curable resin described in detail below, and may contain a photoinitiator and other additives.

[0053] 1.1. UV curable resin

[0054] The UV curable resin of this embodiment refers to a resin that is cured by UV irradiation. The UV curable resin is not particularly limited, and examples thereof include (meth)acrylate oligomers and (meth)acrylate monomers, and these may be used alone or in combination of two or more.

[0055] The specific structure of the (meth)acrylate oligomer is not particularly limited, and examples thereof include carbamate (meth)acrylate oligomers, acrylic resin (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, alkane (meth)acrylate oligomers, and alkylene glycol (meth)acrylate oligomers. Among them, it is preferred to include one or more selected from the group consisting of carbamate (meth)acrylate oligomers, acrylic resin (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, and polyester (meth)acrylate oligomers, and it is further preferred to include carbamate (meth)acrylate oligomers. By using (meth)acrylate oligomers, there is a tendency to improve flexibility.

[0056] The (meth)acrylate monomer is preferably a (meth)acrylate monomer that is compatible with the acrylate oligomer. The specific structure of the (meth)acrylate monomer is not particularly limited, and examples thereof include: methyl (meth)acrylate monomer, ethyl (meth)acrylate monomer, propyl (meth)acrylate monomer, isopropyl (meth)acrylate monomer, butyl (meth)acrylate monomer, isopentyl (meth)acrylate, hexyl (meth)acrylate monomer, 2-ethyl (meth)acrylate monomer, isooctyl (meth)acrylate monomer, isodecyl (meth)acrylate monomer, lauryl (meth)acrylate monomer, stearyl (meth)acrylate monomer, and isobornyl (meth)acrylate monomer. , cyclohexyl (meth)acrylate monomer, benzyl acrylate and other alkyl (meth)acrylate monomers; tripropylene glycol di(meth)acrylate monomer, tetrahydrofurfuryl (meth)acrylate monomer, phenoxyethyl (meth)acrylate monomer, dipentaerythritol hexa(meth)acrylate monomer, tricyclodecane dimethanol di(meth)acrylate monomer, 1,6-hexanediol di(meth)acrylate monomer, phenoxydiethylene glycol (meth)acrylate monomer, 1,4-butanediol di(meth)acrylate monomer, m-phenoxybenzyl (meth)acrylate monomer and other ether-containing acrylate monomers. Among them, it is preferred to include monomers selected from the group consisting of isobornyl (meth)acrylate monomers, tripropylene glycol di(meth)acrylate monomers, tetrahydrofurfuryl (meth)acrylate monomers, phenoxyethyl (meth)acrylate monomers, dipentaerythritol hexa(meth)acrylate monomers, tricyclodecane dimethanol di(meth)acrylate monomers, benzyl (meth)acrylate monomers, stearyl (meth)acrylate monomers, isodecyl (meth)acrylate monomers, isooctyl (meth)acrylate monomers, 1,6-hexanediol di(meth)acrylate monomers, and (meth) One or more selected from the group consisting of lauryl acrylate monomer, m-phenoxybenzyl (meth)acrylate monomer, isoamyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate monomer, and 1,4-butanediol di(meth)acrylate monomer, and more preferably one or more selected from the group consisting of isobornyl (meth)acrylate monomer, tripropylene glycol di(meth)acrylate monomer, tetrahydrofurfuryl (meth)acrylate monomer, phenoxyethyl (meth)acrylate monomer, and dipentaerythritol hexa(meth)acrylate monomer. By using (meth)acrylate monomers, the physical properties of the film such as storage modulus, refractive index, durability, and viscosity can be within an appropriate range.

[0057] Low-viscosity (meth)acrylate monomers are suitable for diluting UV curable resin compositions. Low-viscosity (meth)acrylate monomers are not particularly limited, and examples thereof include isobornyl (meth)acrylate monomers, tripropylene glycol di(meth)acrylate monomers, tetrahydrofurfuryl (meth)acrylate monomers, and phenoxyethyl (meth)acrylate monomers. In this specification, low-viscosity (meth)acrylate monomers refer to (meth)acrylate monomers having a viscosity of 2 Pa·s or less at 25°C.

[0058] The (meth)acrylate monomer having a glass transition temperature of 80° C. or higher is suitable for increasing the storage modulus of the UV curable resin composition. The (meth)acrylate monomer having a glass transition temperature of 80° C. or higher is not particularly limited, and examples thereof include dipentaerythritol hexa(meth)acrylate monomer and isobornyl(meth)acrylate monomer.

[0059] The (meth)acrylate monomer having a glass transition temperature of 5° C. or less is suitable for reducing the storage modulus of the UV curable resin composition. The (meth)acrylate monomer having a glass transition temperature of 5° C. or less is not particularly limited, and examples thereof include phenoxyethyl (meth)acrylate monomers.

[0060] As a multifunctional (meth)acrylate monomer, it is suitable for adjusting the crosslinking density of the UV curable resin composition and increasing the storage modulus. In this specification, the multifunctional (meth)acrylate monomer refers to a (meth)acrylate monomer having two or more functional groups of the same or different structures in one molecule. The functional group is not particularly limited, and examples thereof include acryloyl, epoxy, carboxyl, etc.

[0061] The polyfunctional (meth)acrylate monomer is not particularly limited, and examples thereof include tripropylene glycol di(meth)acrylate monomers that are bifunctional and dipentaerythritol hexaacrylate monomers that are hexafunctional.

[0062] The (meth)acrylate monomer soluble in plastic is preferably used for excellent adhesion to the base film described below. The (meth)acrylate monomer soluble in plastic is not particularly limited, and an example thereof is tetrahydrofurfuryl (meth)acrylate monomer.

[0063] The content of the UV curable resin is preferably 45 to 99 mass %, 50 to 99 mass %, 60 to 99 mass %, 70 to 99 mass %, or 80 to 99 mass % relative to the total solid content of the UV curable resin composition. By making the content of the UV curable resin within the above range, there is a tendency to have excellent scratch resistance and bendability.

[0064] The content of the (meth)acrylate oligomer is preferably 15.0 to 70.0 mass%, 20.0 to 65.0 mass%, 30.0 to 60.0 mass%, 33.0 to 55.0 mass%, or 35.0 to 50.0 mass% relative to the total solid content of the UV curable resin composition. When the content of the (meth)acrylate oligomer is within the above range, there is a tendency for excellent scratch resistance and bending properties.

[0065] The content of the (meth)acrylate oligomer is preferably 20.0 to 80.0 mass%, 25.0 to 70.0 mass%, 30.0 to 60.0 mass%, 33.0 to 50.0 mass%, or 35.0 to 50.0 mass% relative to the total solid content of the UV curable resin. When the content of the (meth)acrylate oligomer is within the above range, there is a tendency for excellent scratch resistance and bendability.

[0066] The content of the (meth)acrylate monomer is preferably 30.0 to 80.0 mass%, 40.0 to 70.0 mass%, 50.0 to 65.0 mass%, or 50.0 to 60.0 mass% relative to the total solid content of the UV curable resin composition. When the content of the (meth)acrylate monomer is within the above range, there is a tendency for excellent scratch resistance and bending properties.

[0067] The content of the (meth)acrylate monomer is preferably 35.0 to 85.0 mass%, 40.0 to 70.0 mass%, 50.0 to 67.0 mass%, or 50.0 to 65.0 mass% relative to the total solid content of the UV curable resin. When the content of the (meth)acrylate monomer is within the above range, there is a tendency for excellent scratch resistance and bendability.

[0068] 1.2. Photopolymerization initiator

[0069] The film of the present embodiment preferably contains a photopolymerization initiator. The photopolymerization initiator of the present embodiment is not particularly limited, and examples thereof include carbonyl compounds such as acetophenone, benzophenone, benzyl, benzoin, acylphosphine oxide, benzoin benzoate, and α-acyloxime ester; sulfur compounds such as tetramethylthiuram monosulfide and thioxanthones; phosphorus compounds such as diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, etc., and they can be used alone or in combination of two or more.

[0070] The specific structure of the photopolymerization initiator is not particularly limited, and examples thereof include 1-hydroxycyclohexyl phenyl ketone and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide.

[0071] The content of the photopolymerization initiator is preferably 0.1 to 10 mass %, 0.5 to 8 mass %, or 1 to 5 mass % relative to the total solid content of the UV curable resin composition. When the content of the photopolymerization initiator is within the above range, the curing speed, flexibility, and scratch resistance tend to be excellent.

[0072] 1.3. Other additives

[0073] The film of the present embodiment may contain other known components that can be used in conventional films in addition to the above-mentioned components. Other components are not particularly limited, and may include colorants, antioxidants, photopolymerization accelerators, ultraviolet absorbers, light stabilizers, flame retardants, fillers, adhesives, other additives, etc. Other components may be used alone or in combination of two or more.

[0074] 1.4. Others

[0075] The film of the present embodiment can be a single-layer film formed by a UV curable resin composition, or a laminated film consisting of a surface layer film formed by a UV curable resin composition and a substrate film supporting the above-mentioned surface layer film. The method of attaching the film of the present embodiment to the substrate is not particularly limited, and for example, a method of directly attaching a single-layer film to the substrate, a method of attaching the substrate film of the laminated film to the substrate via an adhesive, etc. can be cited. In the case of a laminated film, the above-mentioned components are the components of the surface layer film. Here, the substrate is not particularly limited, and for example, it is a component on the surface of a pen input device, specifically, glass, acrylic resin, polyacetal resin, etc. The components of the substrate film are not particularly limited, and for example, the above-mentioned UV curable resin, thermosetting resin, and thermoplastic resin can be cited.

[0076] Examples of the thermosetting resin include phenol resin, epoxy resin, melamine resin, urea resin, polyurethane, and thermosetting polyimide.

[0077] Examples of the thermoplastic resin include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyethylene terephthalate, thermoplastic polyimide, cellulose acetate, and polyethylene naphthalate.

[0078] The substrate film may contain other known components that can be used in conventional films in addition to the above components. Other components are not particularly limited, and may include colorants, stabilizers, flame retardants, fillers, adhesives, other additives, etc. Other components may be used alone or in combination of two or more.

[0079] 2. Film properties

[0080] Hereinafter, each characteristic of the thin film (hereinafter also simply referred to as "thin film") of the present embodiment will be described in detail. However, the present invention is not limited thereto, and various modifications can be made without departing from the gist thereof.

[0081] 2.1. Surface structure

[0082] An uneven shape is formed on the surface of the thin film. Here, the concave shape is a valley based on JIS B0601:2001, and the convex shape is a peak based on JIS B0601:2001. In addition, the average width (RSm) of the contour element based on JIS B0601:2001 is the average width between valleys.

[0083] The maximum valley depth (Rv) based on JIS B0601:2001 is 1.50 μm < Rv < 8.00 μm, preferably 2.00 μm < Rv < 7.50 μm, 2.50 μm < Rv < 7.00 μm. When Rv is within the above range, there is a tendency to have excellent wiping resistance and excellent writing feeling when inputting information to the pen input device pasted with the thin film by a pen-shaped touch device. The maximum valley depth (Rv) based on JIS B0601:2001 can be measured based on JIS B0601:2001. More specifically, it can be measured by the method described in the examples.

[0084] The maximum peak height (Rp) based on JIS B0601:2001 is preferably 0.01 μm < Rp < 1.20 μm, 0.01 μm < Rp < 1.00 μm, 0.01 μm < Rp < 0.90 μm. When Rp is within the above range, there is a tendency to have excellent wiping resistance and excellent writing feeling when inputting information to the pen input device pasted with the thin film by a pen-shaped touch device. The maximum valley depth (Rv) based on JIS B0601:2001 can be measured based on JIS B0601:2001. More specifically, it can be measured by the method described in the examples.

[0085] The maximum valley depth (Rv) and the maximum peak height (Rp) satisfy the relationship of 0.80 < Rv / (Rv + Rp) < 0.90, preferably 0.81 < Rv / (Rv + Rp) < 0.90. When Rv / (Rv + Rp) satisfies the above relationship, there is a tendency to have excellent wiping resistance and excellent writing feeling when inputting information to the pen input device pasted with the thin film by a pen-shaped touch device.

[0086] The average width (RSm) of the contour unit based on JIS B0601:2001 is 30μm<RSm<300μm, preferably 30μm<RSm<200μm, 30μm<RSm<150μm, 30μm<RSm<100μm, 30μm<RSm<90μm. When RSm is in the above range, it has a tendency to have excellent scratch resistance and a writing feel when information is input by a pen-shaped touch device to a pen input device with an attached film. The maximum valley depth (RSm) based on JIS B0601:2001 can be measured based on JIS B0601:2001. More specifically, it can be measured by the method described in the embodiment.

[0087] The surface structure of the film may contain fine particles on the surface of the film, or may not contain fine particles on the surface of the film. From the viewpoint of improving the scratch resistance, it is preferably formed without containing fine particles on the surface of the film.

[0088] The method for controlling Rv, Rp and RSm is not particularly limited, and examples thereof include a method of adjusting the material and particle size of inorganic and / or organic fine particles fixed to the surface of the positive mold in the thin film manufacturing method described later.

[0089] Storage modulus

[0090] The storage modulus of the film is 0.052 to 1.500 GPa, preferably 0.080 to 1.300 GPa, 0.150 to 1.000 GPa, 0.150 to 0.900 GPa. By making the storage modulus of the film the above range, there is a tendency of excellent scratch resistance and flexibility. The storage modulus of the film can be measured by a known method. More specifically, it can be measured by the method described in the examples. In addition, when the film of the present embodiment is a laminated film, the storage modulus is the storage modulus of the surface layer film.

[0091] The method for controlling the storage elastic modulus of the film is not particularly limited, and an example thereof includes a method of controlling the composition of the UV curable resin composition.

[0092] Thickness

[0093] When the film of the present embodiment is a single-layer film, the average thickness of the film of the present embodiment is not particularly limited, and is, for example, 20 to 800 μm, 50 to 500 μm, 75 to 300 μm, or 100 to 200 μm. By making the thickness of the film within the above range, the film tends to have excellent scratch resistance and bendability.

[0094] In the case where the film of the present embodiment is a laminated film comprising a surface layer film formed by a UV curable resin composition and a substrate film supporting the surface layer film, the average thickness of the substrate film is not particularly limited, for example, 1 to 500 μm, 50 to 400 μm, 100 to 300 μm. In addition, the average thickness of the surface layer film is not particularly limited, for example, 10 to 300 μm, 50 to 250 μm, 75 to 200 μm, 75 to 150 μm. By making the thickness of the surface layer film and the substrate film of the film within the above range, the film of the present embodiment has a tendency to be excellent in abrasion resistance and bendability.

[0095] The thickness of the film can be measured by a known method, but is not particularly limited thereto, and can be measured using, for example, a micrometer.

[0096] 3. Film manufacturing method

[0097] The method for producing a film according to the present embodiment includes a coating step of coating a UV curable resin composition and a positive mold transfer step of forming a surface structure of the film by transfer using a positive mold.

[0098] 3.1. Coating process

[0099] When the film involved in this embodiment is a single-layer film, it is not particularly limited, but for example, an uncured UV curable resin composition is coated on a UV-transmissive substrate. When the film involved in this embodiment is a laminated film including a surface layer film formed of a UV curable resin composition and a substrate film supporting the surface layer film, it is not particularly limited, but for example, an uncured UV curable resin composition is coated on a substrate film.

[0100] The UV transmittance is not particularly limited, and may be, for example, a property of transmitting 10% or more, 30% or more, 50% or more, or 70% or more of ultraviolet rays having a wavelength of 365 nm.

[0101] The uncured UV curable resin composition is applied by a known method. The coating method is not particularly limited, and examples thereof include gravure coating, reverse coating, comma coating, die coating, rod coating, curtain coating, roll coating, spray coating, airless spray coating, and thermal spray coating.

[0102] The coating step may be performed after diluting the UV curable resin composition with a solvent. The solvent is not particularly limited, and may be, for example, a non-polar solvent or a polar solvent.

[0103] 3.2. Positive mold transfer process

[0104] The positive mold is a mold for making the film involved in this embodiment, and has a concavo-convex shape in the surface area. The method of imparting the concavo-convex shape to the surface area of ​​the positive mold is not particularly limited, and examples thereof include a method of fixing inorganic and / or organic particles to the surface area of ​​the positive mold, and a method of making the positive mold in a manner that the surface area of ​​the positive mold has a concavo-convex shape.

[0105] The positive mold may be a single-layer structure or a multi-layer structure. In the case of a multi-layer structure, it may include a substrate layer, a rough surface layer on the substrate layer, and a release layer on the rough surface layer, and the rough surface layer and the release layer constitute the surface region of the positive mold. The rough surface layer imparts a concave-convex shape to the surface region of the positive mold, and the release layer facilitates demolding of the positive mold in the film manufacturing method described later.

[0106] When the positive mold has a single-layer structure, it is not particularly limited and may include, for example, the UV curable resin described in 1.1., the thermosetting resin described in 1.4., the thermoplastic resin described in 1.4., and / or inorganic materials such as metal or glass.

[0107] When the positive mold has a multi-layer structure, the base layer is not particularly limited and may include, for example, the UV curable resin described in 1.1., the thermosetting resin described in 1.4., the thermoplastic resin described in 1.4., and / or an inorganic material such as metal or glass.

[0108] When the positive mold has a multi-layer structure, the rough surface layer is not particularly limited, and may include, for example, the UV curable resin described in 1.1., the thermosetting resin described in 1.4., the thermoplastic resin described in 1.4., and / or inorganic materials such as metal or glass, and may also include inorganic and / or organic particles.

[0109] When the positive mold has a multi-layer structure, the release layer is not particularly limited, and may include, for example, the UV curable resin described in 1.1., the thermosetting resin described in 1.4., the thermoplastic resin described in 1.4. and / or inorganic materials such as metal and glass, and may also include release agents such as silicone release agents.

[0110] The inorganic and / or organic particles fixed to the surface area of ​​the positive mold are not particularly limited, and may be particles formed from metal elements, metal compounds, silicon compounds, fluorine compounds, thermoplastic resins, thermosetting resins, or photocurable resins.

[0111] The particle size of the inorganic and / or organic fine particles fixed to the surface region of the positive mold is preferably 0.5 to 40.0 μm, 1.0 to 20.0 μm, or 2.0 to 10.0 μm. When the particle size of the fine particles is within the above numerical range, a thin film satisfying the characteristics described in detail in 2. Thin film characteristics can be easily formed.

[0112] The maximum valley depth (Rv) of the surface area of ​​the positive mold according to JIS B0601:2001 is preferably 0.01 μm. <Rv<1.20μm、0.01μm<Rv<1.10μm。

[0113] The maximum peak height (Rp) of the surface area of ​​the positive mold according to JIS B0601:2001 is preferably 1.50 μm. <Rp<8.00μm、2.00μm<Rp<7.50μm、2.50μm<Rp<7.00μm。

[0114] The maximum valley depth (Rv) and maximum peak height (Rp) of the positive mold are preferably 0.01 <Rv / (Rv+Rp)<0.20、0.10<Rv / (Rv+Rp)<0.15。

[0115] The average width (RSm) of the contour unit of the surface area of ​​the positive mold based on JIS B0601:2001 is preferably 30μm<RSm<300μm, 30μm<RSm<200μm, 30μm<RSm<150μm, 30μm<RSm<100μm, 30μm<RSm<90μm.

[0116] By making the surface area of ​​the positive mold satisfy the above numerical range, a thin film satisfying the characteristics described in detail in 2. Characteristics of the thin film can be easily formed.

[0117] The positive mold may also contain other known components. Other components are not particularly limited, and may include colorants, antioxidants, photopolymerization accelerators, ultraviolet absorbers, light stabilizers, flame retardants, fillers, release agents, other additives, etc. Other components may be used alone or in combination of two or more.

[0118] The method for producing the film of the present embodiment by transferring the shape of the surface region of the positive mold is not particularly limited. For example, after the coating step, the positive mold is laminated on the uncured UV curable resin composition, and UV irradiation is performed from the substrate, substrate film or positive mold side, thereby curing the UV curable resin composition in a state where the concavo-convex shape of the surface region of the positive mold is transferred. Then, the positive mold is demolded to produce the film involved in the present embodiment.

[0119] The light source for UV irradiation is not particularly limited, and examples thereof include a mercury lamp, a high-pressure mercury lamp, a UV-LED, a xenon lamp, and a laser light source.

[0120] The intensity and cumulative intensity of UV irradiation can be appropriately selected according to the composition and thickness of the UV curable resin composition. The intensity of UV irradiation is not particularly limited, and is, for example, 10 mW / cm2 ~10000mW / cm 2 In addition, the integrated intensity of UV irradiation is not particularly limited, and is, for example, 50 to 10,000 mJ / cm 2 .

[0121] 4. Pen-shaped touch devices

[0122] The pen-shaped touch device is a device for inputting information such as text into a pen input device, and is formed of a hard material such as plastic or metal. The plastic is not particularly limited, and examples thereof include polyamide, polyacetal, polycarbonate, and polyphenylene ether. The metal is not particularly limited, and examples thereof include metals such as iron and aluminum, and alloys such as stainless steel. These may be used alone or in combination of two or more.

[0123] The shape of the pen tip is not particularly limited, and is usually a curved shape. The average diameter of the pen tip is not particularly limited, and is, for example, 0.1 to 10.0 mm.

[0124] Example

[0125] Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples. The present invention is not limited to the following Examples at all.

[0126] 1. Film preparation

[0127] 1.1. Preparation of the films of Examples 1 to 5 and Comparative Examples 1 to 2 (thin films of negative mold templates)

[0128] Prepare a UV curable resin composition according to the composition described in Table 1. As a positive mold, a matte release film manufactured by Dainippon Industries, Ltd. is prepared. The matte release film is a substrate layer with a thickness of 25 μm, a rough surface layer composed of "GM60" manufactured by Otsuka Industries, Ltd. containing silica filler, and a release layer composed of "SK-1" manufactured by Dainippon Industries, Ltd. as a silicone-based release coating layer stacked in sequence. The UV curable resin composition is applied to the positive mold by die coating, and a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., Cosmos A4360, thickness 188 μm) as a substrate film is stacked on the coated UV curable resin composition. The laminate is passed between two metal rollers with a gap of a certain distance, so that the UV curable resin composition is spread between the positive mold and the substrate film in a uniform thickness. The gap was adjusted appropriately so that the thickness of the UV curable composition layer after curing was 100 μm. In addition, the thickness of the positive mold was measured by a micrometer. Next, a high pressure mercury lamp (manufactured by Oku Manufacturing Co., Ltd., HHM-7000 / D-FS) was used from the substrate film side at an irradiation intensity of 150±10 mW / cm 2, cumulative irradiation intensity 3000±300mJ / cm 2 The UV curable resin composition is cured by irradiating ultraviolet rays with a main wavelength of 365nm, and the surface layer film is molded and cured to form the surface structure of the film. The intensity of ultraviolet rays is measured using UVR-T1 / UD-T36 manufactured by Topcon. Regarding the measurement conditions, the measurement wavelength is set to 300-390nm, and the peak sensitivity wavelength is set to 355nm. Next, the positive mold is demolded to obtain the films of Examples 1 to 5 and Comparative Examples 1 to 2 (films of negative molds).

[0129] In the positive mold, the maximum valley depth (Rv) of the valley, the maximum peak height (Rp) of the peak, and the average width (RSm) of the contour unit based on JIS B0601:2001 are Rv = 1.02 μm, Rp = 4.25 μm, and RSm = 68.52 μm, respectively. In addition, Rv / (Rv+Rp) = 0.19. In addition, Rv, Rp, and RSm are measured by the method described below.

[0130] 1.2. Preparation of films of Comparative Examples 3 to 9 (films of positive molds)

[0131] A UV curable resin composition was prepared by mixing according to the composition described in Table 2. In a 300 mm×200 mm stainless steel tray with an edge height of 10 mm, the positive mold produced for producing the thin films of Examples 1 to 5 and Comparative Examples 1 to 2 was grounded so that the surface opposite to the surface region (convex shape) was facing the bottom of the stainless steel tray. Then, the base compound for silicone rubber "TSE3455T (made by the Micron Technology Contract Company) was added so that the thickness after curing would become 5 mm. "A)" Our company manufactures curing agent for silicone rubber "TSE3455T(B)" and モメンティブ·パフA silicone rubber liquid prepared by mixing the silicone rubber curing retarder "ME75" manufactured by Ormans Materials and Japan Corporation in a weight ratio of "TSE3455T (A)": "TSE3455T (B)": "ME75" = 100:10:1 was poured into stainless steel, vacuum degassed, and then placed in an oven at 55°C for 7 hours for primary curing. Next, the silicone rubber that had undergone primary curing was peeled off from the positive mold and the stainless steel tray, and the peeled silicone rubber was placed in an oven at 100°C for 20 hours for secondary curing to obtain a negative mold. A UV curable resin composition is applied on the negative mold by die coating, and a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., Cosmoshine A4360, thickness 188 μm) as a substrate film is stacked on the coated UV curable resin composition. The laminate is passed between two metal rollers with a gap of a certain distance, so that the UV curable resin composition is spread between the negative mold and the substrate film in a uniform thickness. The gap is appropriately adjusted in such a way that the thickness of the cured UV curable composition layer is 100 μm. In addition, the thickness of the negative mold is measured by a micrometer. Next, a high pressure mercury lamp (manufactured by Oku Manufacturing Co., Ltd., HHM-7000 / D-FS) is used from the substrate film side with an irradiation intensity of 150±10 mW / cm 2 , cumulative irradiation intensity 3000±300mJ / cm 2 The UV curable resin composition is cured by irradiating ultraviolet rays with a main wavelength of 365nm, and the surface layer film is molded and cured to form the surface structure of the film. The intensity of ultraviolet rays is measured using UVR-T1 / UD-T36 manufactured by Topcon. Regarding the measurement conditions, the measurement wavelength is set to 300-390nm, and the peak sensitivity wavelength is set to 355nm. Next, the positive mold is demolded to obtain the films of Comparative Examples 3 to 9 (films of the positive mold).

[0132] 1.3. Preparation of thin films for storage modulus measurement

[0133] The storage modulus described in Tables 1 and 2 was measured by forming a film from the same UV curable resin composition as the film of each Example and Comparative Example according to the method described below, and the film was measured by the method described later.

[0134] Specifically, a UV curable resin composition was prepared by mixing in a manner to have the composition described in Tables 1 and 2. The UV curable resin composition was applied to the release surface of a release polyethylene terephthalate film A (manufactured by Lintech, PET3811) by die coating, and a release polyethylene terephthalate film B (manufactured by Lintech, PET3811) was laminated on the applied UV curable resin composition so that the release surface was in contact with the UV curable resin composition. The UV curable resin composition was passed between two metal rollers having a gap of a certain distance so that the UV curable resin composition was spread between the release polyethylene terephthalate film A and the release polyethylene terephthalate film B in a uniform thickness. The gap was appropriately adjusted so that the thickness of the UV curable composition layer after curing became 100 μm. Next, a high pressure mercury lamp (HHM-7000 / D-FS manufactured by Oku Seisakusho Co., Ltd.) was used to irradiate the film B from the film B side at an intensity of 150±10 mW / cm 2 , cumulative irradiation intensity 3000±300mJ / cm 2 The UV curable resin composition was cured by irradiating ultraviolet rays with a main wavelength of 365 nm. The intensity of ultraviolet rays was measured using UVR-T1 / UD-T36 manufactured by Topcon. Regarding the measurement conditions, the measurement wavelength was set to 300 to 390 nm, and the peak sensitivity wavelength was set to 355 nm. Then, the film A and the film B were peeled off from the cured UV curable resin composition to obtain a film for storage modulus measurement.

[0135] The materials shown in Tables 1 and 2 are described below.

[0136] [(Meth)acrylate oligomer]

[0137] ・Urethane acrylate oligomer: "KRM7735" manufactured by Toroko Co., Ltd.

[0138] [(Meth)acrylate monomer]

[0139] · Isobornyl acrylate monomer: "IBXA" manufactured by Kyoeisha Chemical Co., Ltd.

[0140] · Tripropylene glycol diacrylate monomer: "TPGDA" manufactured by Dicel Olex Corporation

[0141] ·Tetrahydrofurfuryl acrylate monomer: "THF-A" manufactured by Kyoeisha Chemical Co., Ltd.

[0142] · Phenoxyethyl acrylate monomer: "PO-A" manufactured by Kyoeisha Chemical Co., Ltd.

[0143] ·Dipentaerythritol hexaacrylate monomer: "DPHA" manufactured by Dictura Acrylic Co., Ltd.

[0144] [Photopolymerization initiator]

[0145] 1-Hydroxycyclohexylphenylketone: "Omnirad 184" manufactured by IGM Resins BV

[0146] ·Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide: "TPO" manufactured by IGM Resins BV

[0147] 2. Determination method

[0148] 2.1. Surface roughness parameters

[0149] For the films and positive molds prepared in each of the embodiments and comparative examples, 0.5 mm thick soda-lime glass was adhered and fixed by an adhesive on the surface opposite to the surface of the film serving as the measuring surface, and the maximum valley depth (Rv), the maximum peak height (Rp), and the average width (RSm) of the contour unit were measured using a surface roughness measuring machine (SURFCOM TOUCH50, manufactured by Tokyo Seimitsu Co., Ltd.) under the following conditions and in accordance with JIS B0601:2001.

[0150] Surface roughness detection probe: DM43801 (tip radius: 2 μm) manufactured by Tokyo Seimitsu Co., Ltd.

[0151] ·Measurement speed: 1.5mm / s

[0152] Evaluation length: 4mm

[0153] ·Measurement type: Roughness measurement

[0154] · Shape removal: R surface

[0155] Cutoff category: Gaussian

[0156] Cut-off frequency λc: 0.8mm

[0157] Cut-off frequency λs: 2.5μm

[0158] Storage modulus

[0159] The film for storage modulus measurement was measured using a dynamic viscoelasticity measuring apparatus DMA: Dynamic Mechanical Analysis (manufactured by TA Instruments, RSA-G2) in a tensile mode, a heating rate of 10°C / min, and 1 Hz, and the value at 25°C was read.

[0160] 2.3. Thickness of the surface film

[0161] The thickness of the laminated film obtained by laminating the surface layer film and the base film produced in 1.1. and 1.2. was measured with a micrometer, and the thickness of the surface layer film was calculated by subtracting the previously measured thickness of the base film from the measured thickness.

[0162] 3. Evaluation

[0163] 3.1. Evaluation of scratch resistance

[0164] A hard felt core ACK-20003 manufactured by Wacom Co., Ltd. was installed on a reciprocating abrasion tester Tribodia TYPE30 manufactured by Shinto Chemical Co., Ltd., and the hard felt core was brought into contact with the surface of the film produced in each embodiment and comparative example. Then, 500 reciprocations and 1000 reciprocations were performed on the surface of the film at 23°C and 65% (relative humidity) with a load of 100g, a speed of 3000mm / min, and a moving distance of 50mm, and the evaluation was performed visually according to the following criteria.

[0165] [Evaluation criteria]

[0166] 0: No scratches were generated on the film surface after 500 reciprocating cycles and 1000 reciprocating cycles.

[0167] △: No scratches were generated after 500 reciprocating cycles, but scratches were generated on the surface of the film after 1000 reciprocating cycles. This is a level that does not cause any practical problems.

[0168] ×: After 500 reciprocating cycles, scratches were generated on the surface of the film.

[0169] 3.2. Evaluation of writing quality

[0170] The films produced in the respective Examples and Comparative Examples were evaluated by sensory evaluation using a stylus pen Hi-uniDIGITAL for Wacom manufactured by Mitsubishi Pencil Co., Ltd., according to the following criteria.

[0171] [Evaluation criteria]

[0172] ○: Has moderate writing resistance and can write smoothly.

[0173] △: The writing resistance is slightly larger (or smaller) than the appropriate range, so it is difficult to write and slide. This is a level that is problematic in practical use.

[0174] ×: The writing resistance greatly exceeds (or falls below) the appropriate range, so smooth writing is impossible. This is a level that is problematic in practical use.

[0175] 3.3. Bendability evaluation

[0176] Use the film made in each embodiment and comparative example, carry out bending resistance test according to the cylindrical mandrel method stipulated in JIS K5600-5-1:1999.Use bending test device (BEVS Industrial Co.Ltd system, cylindrical mandrel bending tester), when being wound on the cylindrical mandrel of diameter 10mm in the mode that makes the surface layer film become the outside, visually observe whether the surface layer film has cracked.In addition, different from the film wound on the cylindrical mandrel, for the film made in each embodiment and comparative example, when being bent to 90 ° as the outside, visually observe whether the surface layer film has cracked, evaluate according to the following benchmark.

[0177] [Evaluation criteria]

[0178] ○: No cracks were observed in the surface layer film when it was wound around the cylindrical mandrel and in the surface layer film when it was bent at 90°.

[0179] △: No cracks were observed in the surface layer film when the film was wound around the cylindrical mandrel. Cracks were observed in the surface layer film when the film was bent at 90°, but the film was at a level that was not a problem in practical use.

[0180] ×: Cracks were observed in both the surface layer film when it was wound around the cylindrical mandrel and the surface layer film when it was bent at 90°.

[0181] 3.4. Comprehensive evaluation

[0182] For the evaluation of scratch resistance, writing feel, and bendability, 0 was set to 2 points, △ was set to 1 point, and × was set to 0 points. The total value of all evaluation results was calculated for each Example and Comparative Example, and comprehensive evaluation was performed according to the following criteria.

[0183] [Evaluation criteria]

[0184] ◎: 6 points

[0185] 0: 5 points

[0186] △: 4 points

[0187] ×: 0-3 points

[0188] Tables 1 and 2 show the compositions of the UV curable resin compositions used for preparing the films in the Examples and Comparative Examples, and the measured values ​​and evaluation results of the physical properties.

[0189] [Table 1]

[0190]

[0191] *1: From the left, the numerical values ​​shown are solid content mass ratio / mass percentage (%) relative to the total solid content of the UV curable resin composition / mass percentage (%) relative to the total solid content of the UV curable resin.

[0192] [Table 2]

[0193]

[0194] *1: From the left, the numerical values ​​shown are solid content mass ratio / mass percentage (%) relative to the total solid content of the UV curable resin composition / mass percentage (%) relative to the total solid content of the UV curable resin.

[0195] 4. Evaluation results

[0196] It can be seen from the evaluation results in Tables 1 and 2 that Examples 1 to 5 all exhibit excellent scratch resistance, writing feel and bendability compared to Comparative Examples 1 to 2 in which the storage modulus is outside the specified range and Comparative Examples 3 to 9 in which any one of Rv, Rv / (Rv+Rp) and RSm is outside the specified range.

[0197] This application is based on the Japanese patent application (Japanese Patent Application No. 2022-205378) filed with the Japan Patent Office on December 22, 2022, the entire text of which is incorporated herein by reference.

Claims

1. A film having a surface having valleys and peaks based on JIS B0601:2001, The maximum valley depth (Rv) of the valley, the maximum peak height (Rp) of the peak, and the average width (RSm) of the profile according to JIS B0601:2001 satisfy the following conditions: 1.50μm <Rv<8.00μm; 0.80 <Rv / (Rv+Rp)<0.90; 30μm <RSm<300μm; The storage modulus of the film is 0.052 GPa to 1.500 GPa, The film includes a UV curable resin. 2 . The thin film according to claim 1 , comprising no particles on the surface for forming the valleys and / or peaks. 3 . The film according to claim 1 , wherein the storage modulus of the film is 0.150 GPa to 1.000 GPa. 4 . The film according to claim 1 , wherein the UV curable resin comprises at least one selected from the group consisting of (meth)acrylate oligomers and (meth)acrylate monomers.

5. The film according to claim 4, wherein the (meth)acrylate oligomer comprises at least one selected from the group consisting of urethane (meth)acrylate oligomers, acrylic resin (meth)acrylate oligomers, epoxy (meth)acrylate oligomers and polyester (meth)acrylate oligomers, The (meth)acrylate monomer includes one or more selected from the group consisting of isobornyl (meth)acrylate monomer, tripropylene glycol di(meth)acrylate monomer, tetrahydrofurfuryl (meth)acrylate monomer, phenoxyethyl (meth)acrylate monomer, dipentaerythritol hexa(meth)acrylate monomer, tricyclodecane dimethanol di(meth)acrylate monomer, benzyl (meth)acrylate monomer, stearyl (meth)acrylate monomer, isodecyl (meth)acrylate monomer, isooctyl (meth)acrylate monomer, 1,6-hexanediol di(meth)acrylate monomer, lauryl (meth)acrylate monomer, m-phenoxybenzyl (meth)acrylate monomer, isopentyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate monomer and 1,4-butanediol di(meth)acrylate monomer. 6 . The film according to claim 1 , further comprising a photopolymerization initiator. 7 . The film according to claim 1 , which is a film for a pen input device.

8. A method for producing a thin film, wherein include: A coating step of coating a UV curable resin composition; as well as A process of forming valleys and peaks on the film surface by transfer using a positive mold, wherein the valleys and peaks are based on JIS B0601:2001. In the film, the maximum valley depth (Rv) of the valley, the maximum peak height (Rp) of the peak, and the average width (RSm) of the profile unit based on JIS B0601:2001 satisfy the following conditions: 1.50μm <Rv<8.00μm; 0.80 <Rv / (Rv+Rp)<0.90; 30μm <RSm<300μm; The storage modulus of the film is 0.052 GPa to 1.500 GPa, The film includes a UV curable resin.

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