JP6244182B2 - Transparent laminated film - Google Patents

Description

  The present invention relates to a transparent laminated film that is used for a pen input device such as a touch panel and has improved writing feeling (tactile feeling) by pen input on a surface.

  With the advancement of electronic displays as man-machine interfaces, interactive input systems have become popular. Among them, devices that integrate a touch panel (coordinate input device) with a display are ATMs (automated teller machines), merchandise management, and outwork. (Diplomacy, sales), guidance display, entertainment equipment and so on. Lightweight and thin displays such as liquid crystal displays can be made keyboard-less, and their features are alive, so the number of cases where touch panels are used in mobile devices is increasing. A touch panel is a device that inputs predetermined information or the like to a computer or the like by pressing a predetermined position with an input means such as a finger or a pen. Depending on the method of position detection, an optical method, an ultrasonic method, a capacitance method, etc. , Can be classified into resistive film type. Among these methods, the electrostatic capacitance method is a method for detecting a position by using a change in electrostatic capacitance. However, in recent years, the electrostatic capacitance method adopts an ITO grid method because of its excellent functionality. Capacitive touch panels are in the spotlight as they are used in mobile devices such as smartphones, mobile phones, electronic paper, tablet personal computers (PCs), pen tablets, and game machines. Among them, in recent years, a pen input type touch panel using a pen as an input means has become widespread, and its use is increasing in smartphones, electronic paper, tablet PCs, pen tablets, game machines, PCs, and the like. A hard coat film, an anti-Newton ring film, a soft film, or the like is used on the surface of the touch panel display depending on the application.

  Furthermore, in recent years, pen tablets that use pen input as a pointing device for computers have become widespread and are referred to as pen input devices including the touch panel. In addition, we have developed a high-definition television (4K television) with a touch panel mounted on the display of a high-resolution television (4K television), which has four times the number of pixels on the display panel, and a high-resolution pen input device used in the architectural and medical fields. These devices also require a high degree of transparency.

  However, as pen input devices become widespread in various applications, advanced functions are required for writing in pen input, for example, writing taste that requires writing with a pencil on paper is required. Then, the resistance was so great that it was far from writing like a pencil.

  On the other hand, in a film such as a hard coat film or an anti-Newton ring film, a film that improves the touch feeling (tactile feeling) with a finger by a method of forming an uneven structure on the surface has also been proposed. Japanese Patent Laying-Open No. 2010-153298 (Patent Document 1) discloses a laminate in which a hard coat layer is laminated on one surface of a substrate made of a polyester film and a transparent conductive layer made of a metal oxide is laminated on the other surface. The film has a hard coat layer area surface average roughness Sa of 0.08 to 0.30 μm, a KES surface friction characteristic value average friction coefficient MIU of 0.13 to 0.17, and a coefficient of friction variation MMD of 0. A laminated film for a touch panel that is 0.006 to 0.015 is disclosed. This document describes that it is important to provide protrusions on the surface of the hard coat layer in order to improve the touch feeling of the touch panel by adjusting the surface average roughness and the friction coefficient. In the examples, an acrylic hard coat liquid containing porous silica fine particles having an average particle diameter of 2.5 μm is applied at a thickness of 5 μm, and is cured after drying.

  However, this document does not describe the writing quality of the pen input device. Even if this laminated film is applied to a pen input device, optical characteristics such as glare are not sufficient, and it is particularly difficult to maintain image quality in recent high-definition display devices. The reason for the low optical properties of this film is that when this film is placed on the outermost layer of the device, irregularities are formed on the surface, so that light is diffusely reflected at the interface with air and external haze occurs. It can be estimated that. However, in the prior art, in order to improve the writing quality, it is common knowledge to form and adjust the uneven shape on the surface, and there was a trade-off between advanced optical characteristics and improved writing quality. .

  Regarding the tactile sensation, the film of Patent Document 1 improves the tactile sensation with a finger to some extent, but when used for pen input, the touch pen slips too much. In particular, the writing taste was not constant between the beginning of writing and the middle of writing (while writing), and it was far from writing like a pencil. Further, the fine particles fall off, so that scratches are generated and the writing quality is lowered.

JP 2010-153298 A (Claim 1, paragraphs [0004] and [0014], Examples)

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transparent laminated film that has excellent optical characteristics and can be input with a pen-like writing feel like a pencil in a pen input device.

  Another object of the present invention is to provide a transparent laminated film that can suppress the occurrence of glare and can visually recognize a clear image quality even in a high-definition display device.

  Still another object of the present invention is to provide a transparent laminated film capable of maintaining excellent optical properties and writing quality over a long period of time.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have coated a specific adhesive layer that is laminated on one surface of the base material layer and contains an adhesive and fine particles with a cover layer formed of a transparent resin. Further, the present invention has been completed by finding that the cover layer is hard-coated to provide excellent optical characteristics and that the pen input device can be input with a writing feel like a pencil on paper.

  That is, the transparent laminated film of the present invention includes a base material layer, an adhesive layer that is laminated on one surface of the base material layer, and includes an adhesive and fine particles having an average particle size of 30 to 280 μm, and the adhesive layer. And a transparent laminated film comprising a cover layer containing a transparent resin and a hard coat layer laminated on the cover layer, wherein the adhesive has an elastic modulus of 10 to 3000 Pa, and The elastic modulus of the fine particles is larger than the elastic modulus of the pressure-sensitive adhesive. The weight ratio between the pressure-sensitive adhesive and the fine particles may be about the former / the latter = 90/10 to 50/50. The average thickness of the adhesive layer is about 0.9 to 1.1 times the average particle size of the fine particles. The cover layer has an average thickness of about 9 to 100 μm. The average thickness of the hard coat layer is about 1 to 10 μm. The CV value of the particle diameter of the fine particles may be 35% or less. The arithmetic average roughness Ra of the hard coat layer surface may be 0.1 μm or less. The transparent laminated film of the present invention has a haze of 5% or less, a total light transmittance of 85% or more, and a transmitted image sharpness measured by an image clarity measuring instrument using an optical comb having a width of 0.5 mm. It may be 80% or more.

  In the present invention, a specific adhesive layer that is laminated on one surface of the base material layer and contains an adhesive and fine particles is covered with a cover layer formed of a transparent resin, and the cover layer is further hard-coated. Therefore, in the pen input device, information can be input using a pen with a writing feel like a pencil on paper. Specifically, since the writing quality (friction coefficient profile with respect to the operating distance) can be adjusted to be constant during the beginning and halfway of writing the pen input, it becomes possible to perform delicate pen input, and it is possible to deal with pen input devices having advanced functions. In addition, since the surface is smooth and the occurrence of haze is suppressed, the generation of glare can be suppressed, and a clear image quality can be visually recognized even in a high-definition display device. Further, since the fine particles are filled in the internal adhesive layer and covered with the cover layer and the hard coat layer, the fine particles can be prevented from falling off, and excellent optical characteristics and writing quality can be maintained over a long period of time.

FIG. 1 is a graph of the coefficient of friction against the operating distance of the transparent laminated film obtained in Example 1. FIG. 2 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 2. FIG. 3 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 3. FIG. 4 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 4. FIG. 5 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 5. FIG. 6 is a graph of the coefficient of friction against the operating distance of the transparent laminated film obtained in Example 6. FIG. 7 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 7. FIG. 8 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 8. FIG. 9 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Example 9. FIG. 10 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Comparative Example 1. FIG. 11 is a graph of the coefficient of friction with respect to the operating distance of the transparent laminated film obtained in Comparative Example 2. FIG. 12 is a graph of the coefficient of friction against the working distance of the transparent laminated film obtained in Comparative Example 3. FIG. 13 is a graph of the coefficient of friction against the working distance of the transparent laminated film obtained in Comparative Example 4. FIG. 14 is a graph of the friction coefficient with respect to the operating distance when the 6B pencil is slid on the paper. FIG. 15 is a graph of the friction coefficient with respect to the operating distance when the HB pencil is slid on the paper.

  The transparent laminated film of the present invention is laminated on a base material layer, an adhesive layer laminated on one surface of the base material layer and containing an adhesive and fine particles having an average particle size of 30 to 280 μm, and the adhesive layer. And a cover layer containing a transparent resin, and a hard coat layer laminated on the cover layer. In the present invention, since the adhesive layer having a specific elastic modulus and both surfaces are laminated with other layers is filled with fine particles, the surface is smooth by pressing with a pen even though the surface is smooth. The writing quality can be improved without damaging the optical characteristics or possibly being caught due to deformation.

[Base material layer]
The base material layer only needs to be formed of a transparent material, and can be selected according to the use, and may be an inorganic material such as glass, but an organic material is generally used from the viewpoint of strength and moldability. The organic material may be a curable resin, but is preferably a thermoplastic resin from the viewpoint of moldability. Examples of the thermoplastic resin include polyolefin, styrene resin, acrylic resin, vinyl chloride resin, polyvinyl alcohol resin, polyacetal, polyester, polyarylate, polycarbonate, polyamide, polyimide, polysulfone resin, polyphenylene ether resin, Examples include polyphenylene sulfide resins, fluororesins, and cellulose derivatives. These thermoplastic resins can be used alone or in combination of two or more. When the thermoplastic resin is formed of a transparent resin, it can be used in a pen input device that requires transparency, such as a touch panel display.

  Of these thermoplastic resins, cyclic polyolefins, polyesters, polymethyl methacrylate resins, bisphenol A-type polycarbonates, cellulose esters and the like are preferable, and cellulose esters and polyesters are particularly preferable.

Examples of the cellulose ester include cellulose acetate such as cellulose triacetate (TAC), cellulose acetate C _3-4 acylate such as cellulose acetate propionate, and cellulose acetate butyrate. Examples of the polyester include polyalkylene arylates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

Of these, poly C _2-4 alkylene arylates such as PET and PEN are preferred from the viewpoint of excellent balance such as heat resistance and transparency. Furthermore, the base material layer formed of an organic material may be a biaxially stretched film.

  When the base material layer is formed of an organic material, the conventional additive exemplified in the section of the pressure-sensitive adhesive layer may be contained alone or in combination of two or more, if necessary. The ratio of the additive is, for example, about 0.01 to 10% by weight (particularly 0.1 to 5% by weight) with respect to the entire base material layer. In addition, although the base material layer may contain the granular filler, from the point which can suppress internal haze, it is preferable not to contain a granular filler (fine particle), and other sizes larger than the wavelength of light. It is preferred that no additives be included.

  The average thickness of the base material layer is not particularly limited, and may be 10 μm or more from the viewpoint of handleability and the like, for example, 12 to 500 μm, preferably 20 to 300 μm, and more preferably about 30 to 200 μm.

[Adhesive layer]
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive and fine particles and has a specific elastic modulus, and the elastic modulus of the fine particles is larger than the elastic modulus of the pressure-sensitive adhesive.

(Adhesive)
The elastic modulus of the pressure-sensitive adhesive is 10 to 3000 Pa (especially 30 to 2500 Pa), preferably 50 to 2000 Pa (e.g. 100 to 1500 Pa), more preferably 300 to 1300 Pa (especially 500 to 500) in the method based on JIS K7244. 1000 Pa). When the elastic modulus is too large, deformation is reduced even when pressed with a pen, and writing quality is lowered. On the other hand, if the elastic modulus is too small, the force for fixing the fine particles becomes small due to a decrease in the adhesive force, and the writing quality is lowered. The elastic modulus of the pressure-sensitive adhesive can be determined by measuring the shear elastic modulus by a method according to JIS K7244, and the tensile elastic modulus can be calculated based on the measured shear elastic modulus. For details, the method described in Examples described later Can be measured.

  The pressure-sensitive adhesive is not particularly limited as long as it has such an elastic modulus and is transparent, and may be a conventional transparent pressure-sensitive adhesive. Examples of conventional pressure-sensitive adhesives include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, olefin-based pressure-sensitive adhesives (modified olefin-based pressure-sensitive adhesives), and silicone-based pressure-sensitive adhesives.

  Examples of rubber adhesives include combinations of rubber components (natural rubber, synthetic rubber, thermoplastic elastomer, etc.) and tackifiers (terpene resin, rosin resin, petroleum resin, modified olefin resin, etc.). Can be mentioned.

As an acrylic adhesive, the adhesive comprised with the acrylic copolymer which has acrylic acid _C2-10 alkylester as a main component, such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, can be used, for example. Examples of the copolymerizable monomer of the acrylic copolymer include (meth) acrylic monomers [for example, (meth) acrylic acid, methyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) ) Acrylate, carboxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, acrylamide, N-methylolacrylamide, etc.], polymerizable nitrile compound [For example, (meth) acrylonitrile, etc.], unsaturated dicarboxylic acids or derivatives thereof (for example, maleic anhydride, itaconic acid, etc.), vinyl esters (for example, vinyl acetate, vinyl propionate, etc.), aromatic vinyls (for example, , Styrene, etc.) and the like.

  Examples of the olefin pressure-sensitive adhesive include ethylene- (meth) acrylic acid copolymer, ethylene-2-hydroxyethyl (meth) acrylate copolymer, ethylene-glycidyl (meth) acrylate copolymer, ethylene-vinyl acetate- Examples thereof include (meth) acrylic acid copolymers, ethylene-ethyl (meth) acrylate- (anhydrous) maleic acid copolymers, and partially saponified products of ethylene-vinyl acetate copolymers.

Examples of the silicone-based pressure-sensitive adhesive include a silicone rubber component [monofunctional R ₃ SiO _1/2 (wherein, R represents an alkyl group such as a methyl group, an aryl group such as a phenyl group, etc., the same applies hereinafter). And MQ resin composed of tetrafunctional SiO ₂ ] and a silicone resin component (bifunctional R ₂ SiO alone or bifunctional R ₂ SiO and monofunctional R ₃ SiO _1/2 combined oily or gum) And the like can be used. The silicone rubber component may be cross-linked.

  Among these pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferable from the viewpoints of heat resistance and optical characteristics.

  The refractive index of the pressure-sensitive adhesive is such that the difference in refractive index from the fine particles is 0.03 or less, preferably 0.02 or less, more preferably 0.01 or less, from the viewpoint of suppressing internal haze and improving transparency.

(Fine particles)
The elastic modulus of the fine particles only needs to be larger than the elastic modulus of the pressure-sensitive adhesive, and the difference between the elastic modulus of the fine particles and the elastic modulus of the pressure-sensitive adhesive is, for example, 0.01 MPa or more, preferably 1 MPa or more, more preferably 10 MPa or more ( In particular, it may be 100 MPa or more. The specific elastic modulus of the fine particles can be selected from the range of about 0.01 to 10000 MPa, and is, for example, about 1 to 50000 MPa, preferably 10 to 30000 MPa, more preferably about 100 to 10000 MPa (particularly 1000 to 5000 MPa). If the elastic modulus of the fine particles is too small, even when pressed with a pen and input, the formation of uneven shapes due to deformation is not sufficient, and the writing quality is lowered. The elastic modulus of the fine particles can be calculated based on the compression displacement by performing a compression test using a micro compression tester, and can be measured in detail by the method described in Examples described later.

  Examples of the shape of the fine particles include a spherical shape, an ellipsoidal shape, a polygonal shape (polygonal pyramid shape, a rectangular parallelepiped shape, a rectangular parallelepiped shape, etc.), a plate shape, a rod shape, and an indefinite shape. Among these shapes, a shape that does not have an acute angle portion, for example, a spherical shape or an ellipsoid shape, is preferable because it can be appropriately hooked to the pen tip and input with a writing feeling (tactile feeling) like a pencil. A true spherical shape is particularly preferable.

  The average particle diameter of the fine particles can be selected from the range of about 30 to 280 μm, and is, for example, about 40 to 260 μm, preferably 50 to 250 μm, and more preferably about 60 to 230 μm (particularly 100 to 200 μm). If the particle size is too small, the surface will not be sufficiently deformed even with pen input, and it will slip too much and the writing quality will deteriorate. On the other hand, if the particle size is too large, the distance between the adjacent convex portion and the convex portion becomes too long, so that the frequency with which the pen is caught is lowered and the writing quality is lowered. The average particle diameter of the fine particles can be measured by a method using laser diffraction.

  The particle size distribution of the fine particles is preferably narrow from the viewpoint that a desired uneven shape generated by pen input can be obtained in a small amount, and transparency and mechanical strength can be improved. The particle size distribution of the fine particles is represented by a CV value (correlation coefficient: ratio of standard deviation to average particle size), and the CV value may be 35% or less (particularly 32% or less). It is about -20% (for example, 1-18%), Preferably it is 2-17%, More preferably, it is about 3-15% (especially 4-10%).

  The fine particles only have to have such an elastic modulus and particle diameter, and the material is not particularly limited, and may be inorganic particles or organic particles.

  Examples of the inorganic particles include simple metals, metal oxides, metal sulfates, metal silicates, metal phosphates, metal carbonates, metal hydroxides, silicon compounds, fluorine compounds, and natural minerals. The inorganic particles may be surface-treated with a coupling agent (titanium coupling agent, silane coupling agent). These inorganic particles can be used alone or in combination of two or more. Of these inorganic particles, metal oxide particles such as titanium oxide, silicon compound particles such as silicon oxide, and fluorine compound particles such as magnesium fluoride are preferable from the viewpoint of transparency and the like, and low reflection and low haze are preferable. Silica particles are particularly preferable in that

  Examples of the organic particles include thermoplastic resins such as acrylic resin, polyamide resin, polyamideimide resin, and polyacetal resin, crosslinked heat such as crosslinked polyolefin resin, crosslinked (meth) acrylic resin, crosslinked polystyrene resin, and crosslinked polyurethane resin. Examples thereof include particles formed of a thermosetting resin such as a plastic resin or an epoxy resin. These organic particles can be used alone or in combination of two or more. Among these organic particles, crosslinked polymer particles such as polyamide particles, crosslinked poly (meth) acrylic acid ester particles, crosslinked polystyrene particles, and crosslinked polyurethane particles are widely used.

  Of these, organic particles such as crosslinked resin particles are preferred from the viewpoint of excellent balance between transparency and elasticity, and crosslinked poly (meth) acrylate-based particles from the viewpoint of excellent balance between optical properties and mechanical strength. Is particularly preferred.

Examples of the poly (meth) acrylic acid ester constituting the crosslinked poly (meth) acrylic acid ester particles include (meth) poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly (meth) butyl acrylate and the like. _Examples thereof include poly (meth) acrylic acid alkyl ester resins containing C _1-6 alkyl acrylate (particularly C _2-6 alkyl) as a main component (about 50 to 100% by weight, preferably about 70 to 100% by weight). As the crosslinking agent, a conventional crosslinking agent can be used. For example, a compound having two or more ethylenically unsaturated bonds (ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate) (Poly) C _2-10 alkylene glycol di (meth) acrylate, bifunctional vinyl compounds such as divinylbenzene, trifunctional or more polyfunctional vinyl compounds such as trimethylolpropane tri (meth) acrylate, and the like can be used. . The proportion of the crosslinking agent may be about 0.1 to 10 mol% (particularly 1 to 5 mol%) of all monomers. The cross-linked poly (meth) acrylate-based particles may be cross-linked polymethacrylic acid ester particles such as cross-linked polymethyl methacrylate particles in order to improve slidability. Moreover, you may improve a softness | flexibility using bridge | crosslinking polyacrylic acid ester particle | grains.

  The refractive index of the fine particles is, for example, 1.4 to 1.6, preferably 1.41 to 1.58, more preferably 1.42 to 1.55 (especially 1.45 to 1.55) from the viewpoint of improving transparency. It may be about 1.53).

  The weight ratio between the pressure-sensitive adhesive and the fine particles can be selected from the range of the former / the latter = 97/3 to 30/70 according to the particle size of the fine particles, for example, 95/5 to 40/60, preferably 90 / It is about 10-50 / 50, More preferably, it is about 85 / 15-60 / 40 (especially 85 / 15-70 / 30). If the proportion of the fine particles is too small, the surface will not be sufficiently deformed even with a pen input, and the writing quality will deteriorate due to slipping too much. On the other hand, if the proportion of fine particles is too large, the mechanical properties and transparency of the laminated film are lowered.

(Characteristics of adhesive layer)
In addition to the pressure-sensitive adhesive and fine particles, the pressure-sensitive adhesive layer contains conventional additives such as curing agents or cross-linking agents, other resin components, and stabilizers (antioxidants, ultraviolet absorbers, light-resistant stabilizers, heat stabilizers). Etc.), colorants, crystal nucleating agents, plasticizers, flame retardants, flame retardant aids, antistatic agents, dispersants, surfactants, waxes, antibacterial agents and the like. These additives can be used alone or in combination of two or more. The ratio of these additives should just be a range which does not impair the transparency of an adhesion layer, for example, is about 0.01-10 weight% (especially 0.1-5 weight%) with respect to the whole adhesion layer. .

  In particular, when a curable adhesive (for example, an adhesive having a reactive group in a side chain) is used as the adhesive, the elastic modulus of the adhesive may be adjusted by blending a curing agent or a crosslinking agent. . Examples of the curing agent or cross-linking agent include an isocyanate compound having a plurality of isocyanate groups, an aziridine compound having a plurality of aziridinyl groups, an epoxy compound having a plurality of glycidyl groups, and a plurality of oxazoline groups, depending on the type of pressure-sensitive adhesive. Examples thereof include oxazoline compounds, melamine compounds, and metal chelate compounds.

  The average thickness of the pressure-sensitive adhesive layer is preferably substantially the same as the average particle diameter of the fine particles from the viewpoint that both the writing quality of pen input and the fixation of the fine particles can be achieved. It is 0.8 to 1.2 times, preferably 0.9 to 1.1 times, and more preferably about 0.95 to 1.05 times. The average thickness of the pressure-sensitive adhesive layer can be selected from a range of about 30 to 280 μm, for example, about 40 to 260 μm, preferably about 50 to 250 μm, and more preferably about 60 to 230 μm (particularly about 100 to 200 μm). In addition, the average thickness of an adhesion layer can be measured as an average value of arbitrary 10 places, for example using an optical film thickness meter.

[Cover layer]
The cover layer needs to bend by pressing with a pen, and is formed of a transparent resin. Examples of the transparent resin include the thermoplastic resins exemplified in the section of the base material layer. Among the thermoplastic resins, cyclic polyolefins, polyesters, polymethyl methacrylate resins, bisphenol A type polycarbonates, cellulose esters and the like are widely used, cellulose esters and polyesters are preferable, and from the viewpoint of excellent balance of heat resistance and transparency. Poly _C2-4 alkylene arylates such as PET and PEN are particularly preferred. Further, the cover layer formed of an organic material may be a biaxially stretched film.

  The cover layer may contain conventional additives exemplified in the section of the pressure-sensitive adhesive layer alone or in combination of two or more as necessary. The ratio of the additive is, for example, about 0.01 to 10% by weight (particularly 0.1 to 5% by weight) with respect to the entire cover layer. In addition, it is preferable that a cover layer does not contain a granular filler, and it is preferable not to contain the other additive of the size larger than the wavelength of light.

  The average thickness of the cover layer may be 150 μm or less (particularly 120 μm or less), for example, 9 to 100 μm (for example, 50 to 100 μm), preferably 10 to 90 μm (for example, 20 to 80 μm), and more preferably 30 to 30 μm. It is about 70 μm (particularly 50 to 70 μm). When the thickness of the cover layer is too thick, flexibility is lowered and writing quality by pen input is lowered.

[Hard coat layer]
The hard coat layer is not particularly limited as long as it is a transparent and highly scratch-resistant material, and may be formed of a conventional curable resin used as the hard coat layer. The curable resin is a compound having a functional group that reacts with, for example, heat or active energy rays (such as ultraviolet rays or electron beams). Various resins that can be cured or crosslinked with heat or active energy rays to form a resin. Curable compound, for example, thermosetting compound or resin [epoxy group, polymerizable group, isocyanate group, alkoxysilyl group, silanol group, etc., low molecular weight compound (for example, epoxy resin, unsaturated polyester resin, urethane type) Resin, silicone resin, etc.)], photocurable compounds curable by active energy rays (photocurable compounds such as photocurable monomers and oligomers), and the like. These curable resins can be used alone or in combination of two or more.

  Among these curable resins, a photocurable compound having two or more functions (preferably about 2 to 10 functions, more preferably about 3 to 8 functions) is preferable, and it is photocurable from the viewpoint of excellent balance between transparency and strength. Acrylic resins are particularly preferred. As the photocurable acrylic resin, a (meth) acrylate having 2 or more (for example, about 2 to 8) (meth) acryloyl groups in a molecule is widely used, and a trifunctional or more functional (meth) is used in terms of strength. Preferred are acrylates (for example, pentaerythritol tri to tetra (meth) acrylate, dipentaerythritol penta to hexa (meth) acrylate, etc.).

  The hard coat layer may contain, as necessary, conventional additives and polymerization initiators exemplified in the section of the pressure-sensitive adhesive layer alone or in combination of two or more. The ratio of the additive or the polymerization initiator is, for example, about 0.01 to 10% by weight (particularly 0.1 to 5% by weight) with respect to the entire hard coat layer. In addition, it is preferable that a hard-coat layer does not contain a granular filler, and it is preferable not to contain the other additive of the size larger than the wavelength of light.

  The average thickness of the hard coat layer may be 20 μm or less, for example, 0.5 to 20 μm, preferably 0.8 to 15 μm, and more preferably about 1 to 10 μm. When the thickness of the hard coat layer is too thick, flexibility is lowered, writing quality by pen input is lowered, and curling due to curing shrinkage is also generated.

[Transparent laminated film]
The transparent laminated film of the present invention has a smooth hard coat layer surface, and may have an arithmetic average roughness Ra of 0.1 μm or less in accordance with JIS B0601, for example, 1 to 80 nm, preferably 2 to 50 nm, More preferably, it is about 3-30 nm (especially 5-20 nm). When the surface roughness increases, the external haze increases, so that the optical characteristics deteriorate.

  Although the transparent laminated film of the present invention has a smooth surface, it has an appropriate friction coefficient with pen input and can improve the writing quality. Specifically, when the effective measurement distance is 20 mm, the average friction coefficient may be 0.05 or more, for example, 0.1 to 0.5, preferably 0.12 to 0.45, more preferably Is about 0.15 to 0.4 (particularly 0.2 to 0.35). If the friction coefficient is too low, it tends to slip too much, and if it is too high, it will be caught too much.

  The standard deviation of the friction coefficient may be 0.01 or more, for example, 0.01 to 0.3, preferably 0.02 to 0.25, more preferably 0.03 to 0.22 (especially 0. 05 to 0.2). When the standard deviation is too small, the feeling of catching is lowered, and when the standard deviation is too large, the writing quality is lowered.

  Further, the ratio of the standard deviation of the first 10 mm to the standard deviation of the second 10 mm (the former / the latter) may be 0.25 to 4, for example, 0.4 to 3, preferably 0.5 to 2.5. More preferably, it is about 0.8 to 2 (particularly 0.9 to 1.5). When this ratio is within these ranges, the profile of the coefficient of friction with respect to the operating distance can be adjusted to be substantially constant during and after writing pen input (during pen input). You can input with the writing taste. On the other hand, if this ratio is too small or too large, the writing quality is lowered.

  In this specification, a friction coefficient can be measured using a static friction measuring machine, and can be measured by the method described in the below-mentioned Example in detail.

  The transparent laminated film of the present invention is excellent in optical properties such as transparency, and the total light transmittance in accordance with JIS K7136 may be 80% or more (particularly 85% or more). It is about 9%, preferably 86-99.5%, more preferably about 88-99% (particularly 90-95%).

  Since the transparent laminated film of the present invention has a smooth surface, external haze is suppressed. Therefore, the transparent laminated film of this invention can adjust the haze based on JISK7136 to 10% or less, for example, 5% or less (for example, 0.1-5%), Preferably it is 0.3-4. %, More preferably about 0.5 to 3% (especially 1 to 2.5%). In the present invention, since haze can be suppressed, it is suitable for high-definition display.

  When the transparent comb film of the present invention has a transmission image definition (mapping definition) of 0.5 mm width, for example, it may be 70% or more (particularly 80% or more), for example, 80 ˜100%, preferably 82 to 99%, more preferably 83 to 95% (especially 85 to 90%). If the transmitted image definition is too low, it becomes difficult to visually recognize a clear image quality even in a high-definition display device.

  The transmitted image definition is a scale for quantifying blur and distortion of light transmitted through a film. The transmitted image definition is measured through an optical comb that moves the transmitted light from the film, and a value is calculated based on the amount of light in the bright and dark portions of the optical comb. That is, when the film blurs the transmitted light, the image of the slit formed on the optical comb becomes thick, so that the amount of light at the transmissive portion is 100% or less, while the light leaks at the non-transmissive portion, so 0% That's it. The value C of the transmitted image definition is defined by the following equation from the maximum transmitted light value M of the transparent portion and the minimum transmitted light value m of the opaque portion of the optical comb.

C (%) = [(M−m) / (M + m)] × 100
That is, the closer the value of C is to 100%, the smaller the blur of the image due to the transparent conductive film [Reference: Suga, Mitamura, Painting Technology, July 1985 issue].

  The transparent laminated film may be combined with other functional layers such as a transparent conductive layer, an anti-Newton ring layer, an antiglare layer, a light scattering layer, an antireflection layer, a polarizing layer, and a retardation layer.

  The transparent laminated film of the present invention may be used for disposing on the outermost surface of the display, and the writing quality can be adjusted to be substantially constant at the beginning of writing and in the middle of writing, and the writing can be done with a writing feel like a pencil on paper. Therefore, it can be used for a pen input device such as a pen input type touch panel display or a pen tablet, and is arranged to be positioned on the outermost surface of the display. In particular, since the tactile sensation film of the present invention is excellent in transparency and writing quality, it is suitable for displays of various pen input type touch panels (particularly, projection type capacitive touch panel adopting the ITO grid system), particularly 4K television displays. It is suitable for the operation of high-resolution televisions equipped with touch panels and high-resolution pen input devices used in the architectural and medical fields.

  The pen (contactor) used in the pen input device only needs to be formed of a hard material such as plastic or metal, and is usually formed of plastic. Examples of the plastic include, for example, a polyacetal resin, an aromatic polyester resin, a polyamide resin, a polycarbonate resin, a polyphenylene ether resin, a polyphenylene sulfide resin, and a polysulfone resin from the viewpoint of strength and durability. These resins can be used alone or in combination of two or more. Of these, polyacetal resins such as polyoxymethylene are preferable because they are lightweight, have high strength, and are excellent in durability such as wear resistance and sliding properties. The shape of the nib is not particularly limited, but is usually a curved surface shape (R shape). The average diameter of the nib is not particularly limited, but can be selected, for example, from the range of about 0.1 to 10 mm, preferably 0.3 to 8 mm, more preferably about 0.3 to 5 mm, but usually 0. It is about 5 to 3 mm (especially 0.6 to 2 mm).

[Method for producing transparent laminated film]
The transparent laminated film of the present invention is not particularly limited and can be produced by a conventional method. For example, after laminating an adhesive layer on a base material layer, it may be in close contact with a cover layer on which a hard coat layer has been laminated in advance. .

  The method of laminating the adhesive layer on the base material layer may be a method of coating one surface of the base material layer with a liquid composition for forming the adhesive layer. Examples of the coating method include a roll coater, an air knife coater, a blade coater, a rod coater, a reverse coater, a bar coater, a comma coater, and a die coater.

  The liquid composition for forming the adhesive layer may contain a solvent in order to improve applicability. As the solvent, for example, ketones (acetone, methyl ethyl ketone, etc.), ethers (tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.) depending on the type of adhesive. , Aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, etc.), esters (methyl acetate, etc.), water, alcohols (ethanol, isopropanol, etc.), cellosolves, cellosolve acetates, sulfoxides And amides. These solvents can be used alone or in combination of two or more. In the case of using a solvent, the liquid composition may have a solid content of about 10 to 80% by weight (particularly 30 to 70% by weight), for example.

  If the liquid composition contains an organic solvent, it may be dried as necessary after coating. Drying may be performed, for example, at a temperature of about 40 to 150 ° C., preferably 50 to 120 ° C., and more preferably about 60 to 100 ° C.

  The method of laminating the hard coat layer on the cover layer may be a method of curing after coating a curable composition for forming a hard coat layer on one surface of the cover layer.

  As a coating method of the curable composition, the coating method exemplified in the coating method of the liquid composition can be used.

  Similarly to the liquid composition, the curable composition may contain an organic solvent, and may be dried by the same method as necessary, for example, when it contains an organic solvent.

  Although hardening of a curable composition may be heated and hardened according to the kind of polymerization initiator, it can be normally hardened | cured by irradiating an active energy ray. As active energy rays, for example, radiation (gamma rays, X-rays, etc.), ultraviolet rays, visible rays, electron beams (EB), etc. can be used, and usually ultraviolet rays are often used.

As the light source, for example, in the case of ultraviolet rays, a Deep UV lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a halogen lamp, a laser light source (light source such as a helium-cadmium laser or an excimer laser) may be used. it can. Irradiation light amount (irradiation energy) varies depending on the thickness of the coating film, for example, 50~10000mJ / cm ^2, preferably 70~5000mJ / cm ^2, more preferably about 100~1000mJ / cm ^2.

  In addition, you may perform irradiation of an active energy ray in inert gas (for example, nitrogen gas, argon gas, helium gas etc.) atmosphere if necessary.

  In order to improve the adhesion of the hard coat layer to the cover layer, the cover layer may be subjected to a surface treatment. Examples of the surface treatment include conventional surface treatments such as corona discharge treatment, flame treatment, plasma treatment, ozone and ultraviolet irradiation treatment. The surface of the cover layer may be easily adhered.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The transparent laminated films obtained in Examples and Comparative Examples were evaluated according to the following items.

[Average thickness of adhesive layer and clear hard coat layer (HC layer)]
Using an optical film thickness meter, 10 arbitrary positions were measured, and an average value was calculated.

[Elastic modulus of adhesive]
The shear modulus (G ′) of the adhesive was measured according to JIS K7244 using a melt viscoelasticity measuring device (“MCR-302” manufactured by Anton Paar). Based on the measured shear modulus, the tensile modulus (E ′) was calculated from the following equation. Since the Poisson's ratio of the polymer is generally μ = 0.5, the calculation was performed with E ′ = 3G ′.

E ′ = 2 * G ′ * (1 + μ)
(Wherein μ: Poisson ratio).

[Elastic modulus of fine particles]
One independent fine particle was selected and subjected to a compression test. A micro compression tester (“MCTW-500” manufactured by Shimadzu Corporation) was used as the compression tester, and a diamond flat indenter (diameter φ = 50 μm) was used as the indenter. For the calculation of the elastic modulus, data in the region of compression displacement = about 0.05 μm to about 0.5 μm was used.

[Arithmetic mean roughness Ra]
Based on JIS B0601, the arithmetic average roughness Ra was measured using a contact-type surface roughness meter (manufactured by Tokyo Seimitsu Co., Ltd., surfcom 570A) under the conditions of a scanning range of 3 mm and a scanning frequency of 2 times.

[Haze and total light transmittance]
Using a haze meter (trade name “NDH-5000W” manufactured by Nippon Denshoku Co., Ltd.), haze (HZ) and total light transmittance (TT) were measured according to JIS K7136. The haze was measured by placing the hard coat layer on the light receiver side.

[Transparent image clarity]
The image clarity (transmission image clarity) of the obtained transparent laminated film was measured using an image measuring instrument (trade name “ICM-1T” manufactured by Suga Test Instruments Co., Ltd.) and an optical comb (comb width = 0.5 mm), and measured based on JIS K7105.

[Roughness]
The surface of the hard coat layer was slid with a touch pen for Nintendo DS (registered trademark) to evaluate the unevenness, and evaluated according to the following criteria.

○: Feels unevenness ×: Does not feel unevenness

[Coefficient of friction]
Using a static friction measuring machine ("Handy Tribomaster TL201Ts" manufactured by Trinity Lab Co., Ltd.), the friction force was measured under measurement conditions (load 50 g weight, speed 50 mm / sec). As a contact, a polyoxymethylene pen (pen tip diameter: 0.8 mmφ) was used and slid at an angle of 45 ° with respect to the film. As a reference example, pencils (“Uni 6B” and “Uni HB” manufactured by Mitsubishi Pencil Co., Ltd.) were slid on paper (“Copy Paper Standard Type” manufactured by Cownet Co., Ltd.).

[Materials used]
PET film: “A4300” manufactured by Toyobo Co., Ltd., thickness 50 μm or 100 μm
TAC film: “Fujitac” manufactured by Fuji Film Co., Ltd., thickness 80 μm
Adhesive: “T-45AD” manufactured by Seiden Chemical Co., Ltd.
Hardener: “Hardener AL” manufactured by Syden Chemical Co., Ltd.
Acrylic particles (20 μm): “Kemisnow MX-2000” manufactured by Soken Chemical Co., Ltd., average particle size 18-22 μm, CV value 17.1%, crosslinked polymethacrylic acid ester particles Acrylic particles (50 μm): Toyo “FH-S050” manufactured by Spinning Co., Ltd., average particle size 50 μm, crosslinked polymethacrylic acid ester particles Acrylic particles (100 μm): “Techpolymer MBX-100” manufactured by Sekisui Plastics Co., Ltd., average particle size 100 μm, CV Value 31.3%, crosslinked polymethacrylic acid ester particles Acrylic particles (200 μm): “Techpolymer MBX-200” manufactured by Sekisui Plastics Co., Ltd., average particle size 200 μm, CV value 26.0%, crosslinked polymethacrylic acid Ester particles Acrylic particles (300 μm): “Techpolymer MBX-300” manufactured by Sekisui Plastics Co., Ltd., average particle size 300 μm CV value 20.2%, crosslinked polymethacrylate particles urethane particles: Negami Chemical Industry Co., Ltd. "C-100 clear", average particle diameter 50μm
Clear hard coat liquid: UV curable acrylic hard coat liquid, "Aika Itron Z-888-7" manufactured by Aika Industry Co., Ltd.
Multifunctional acrylate: 5-6 functional acrylic UV curable monomer, “DPHA” manufactured by Daicel-Cytec Co., Ltd.
Initiator A: Photopolymerization initiator, “Irgacure 184” manufactured by Ciba Japan Co., Ltd.
Initiator B: Photopolymerization initiator, “Irgacure 907” manufactured by Ciba Japan Co., Ltd.

Example 1
A liquid composition was prepared by adding a pressure-sensitive adhesive and acrylic particles having a particle diameter of 50 μm in a weight ratio of solid content in a ratio of pressure-sensitive adhesive / acrylic particles = 90/10. Using an applicator (clearance: 100 μm), the liquid composition is applied onto a PET film (thickness: 100 μm) as a base material layer, dried at a temperature of 80 ° C. for 5 minutes, and applied to one surface of the base material layer. A laminated film A in which an adhesive layer having a thickness of 50 μm was laminated was obtained.

On the other hand, a clear hard coating solution was applied onto a PET film (thickness 50 μm) as a cover layer using a Mayer bar (# 14), and dried at a temperature of 80 ° C. for 1 minute. After drying, using an ultraviolet irradiation device (made by Eye Graphics Co., Ltd., metal halide lamp), under a nitrogen gas atmosphere, an ultraviolet ray is irradiated at an irradiation amount of 200 mJ / cm ² to perform a curing treatment, and one of the cover layers A laminated film B having a 3 μm thick clear hard coat layer laminated on the surface was obtained.

Both films were laminated so that the pressure-sensitive adhesive layer of the laminated film A and the cover layer of the laminated film B were in contact with each other, and pressed and adhered with a rubber roller at a pressure of 400 g / cm ² to obtain a transparent laminated film.

Example 2
A liquid composition was prepared by adding a pressure-sensitive adhesive and acrylic particles having a particle diameter of 100 μm in a weight ratio of solid content in a ratio of pressure-sensitive adhesive / acrylic particles = 90/10. Using an applicator (clearance: 200 μm), the liquid composition is applied onto a PET film (thickness: 100 μm) as a base material layer, dried at a temperature of 80 ° C. for 5 minutes, and applied to one surface of the base material layer. A laminated film A in which an adhesive layer having a thickness of 100 μm was laminated was obtained. Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Example 3
A laminated film A was obtained in the same manner as in Example 2 except that the pressure-sensitive adhesive and acrylic particles having a particle diameter of 100 μm were added at a ratio of solid / weight ratio of pressure-sensitive adhesive / acrylic particles = 50/50. . Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Example 4
A transparent laminated film was obtained in the same manner as in Example 2 except that a PET film having a thickness of 100 μm was used as the cover layer.

Example 5
A liquid composition was prepared by adding a pressure-sensitive adhesive and acrylic particles having a particle diameter of 200 μm in a weight ratio of solid content in a ratio of pressure-sensitive adhesive / acrylic particles = 80/20. Using an applicator (clearance 400 μm), the liquid composition is applied onto a PET film (thickness 100 μm), which is a base material layer, and dried at a temperature of 80 ° C. for 5 minutes. A laminated film A in which an adhesive layer having a thickness of 200 μm was laminated was obtained. Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Example 6
In addition to the pressure-sensitive adhesive and the acrylic particles, a laminated film A was obtained in the same manner as in Example 5 except that a curing agent was further blended at a ratio of 1% by weight with respect to the pressure-sensitive adhesive. Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Example 7
A transparent laminated film was obtained in the same manner as in Example 2 except that a TAC film having a thickness of 80 μm was used as the cover layer.

Example 8
A transparent laminated film was obtained in the same manner as in Example 1 except that urethane particles having a particle diameter of 50 μm were used instead of acrylic particles having a particle diameter of 50 μm.

Example 9
A transparent laminated film was obtained in the same manner as in Example 2 except that the thickness of the clear hard coat layer was changed to 10 μm.

Comparative Example 1
A liquid composition was prepared by adding a pressure-sensitive adhesive and acrylic particles having a particle diameter of 20 μm in a weight ratio of solid content in a ratio of pressure-sensitive adhesive / acrylic particles = 95/5. Using an applicator (clearance of 40 μm), the liquid composition is applied onto a PET film (thickness of 100 μm) as a base material layer, dried at a temperature of 80 ° C. for 5 minutes, and applied to one surface of the base material layer. A laminated film A in which an adhesive layer having a thickness of 20 μm was laminated was obtained. Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Comparative Example 2
A liquid composition was prepared by adding a pressure-sensitive adhesive and acrylic particles having a particle size of 300 μm in a weight ratio of solid content in a ratio of pressure-sensitive adhesive / acrylic particles = 70/30. Using an applicator (clearance: 600 μm), the liquid composition is applied onto a PET film (thickness: 100 μm) as a base material layer, dried at a temperature of 80 ° C. for 5 minutes, and applied to one surface of the base material layer. A laminated film A in which an adhesive layer having a thickness of 300 μm was laminated was obtained. Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Comparative Example 3
In addition to the pressure-sensitive adhesive and the acrylic particles, a laminated film A was obtained in the same manner as in Example 5 except that a curing agent was added at a ratio of 2% by weight to the pressure-sensitive adhesive. Using the obtained laminated film A, a transparent laminated film was obtained in the same manner as in Example 1.

Comparative Example 4
In a weight ratio in terms of solid content, 100 parts by weight of polyfunctional acrylate, 5 parts by weight of acrylic particles having a particle size of 20 μm, 2.5 parts by weight of initiator A, and 2.5 parts by weight of initiator B were mixed with a mixed solvent of toluene and isopropanol (toluene / It was dissolved in isopropanol = 6/4 (volume ratio)) to prepare a liquid composition having a solid content concentration of 25% by weight. The obtained liquid composition was coated on a PET film (thickness: 100 μm) using a wire bar # 38, and dried at a temperature of 60 ° C. for 1 minute. After drying, an ultraviolet ray irradiation device (made by Eye Graphics Co., Ltd., metal halide lamp) is used to irradiate the ultraviolet ray at a dose of 800 mJ / cm ² in a nitrogen gas atmosphere to perform a curing treatment, and acrylic particles are formed on the surface. A transparent laminated film having a protruding concavo-convex structure was obtained.

  Table 1 shows the results of evaluating the transparent laminated films obtained in the examples and comparative examples. In Table 1, the composition of the adhesive layer is the weight ratio of the solid content.

  As is clear from the results in Table 1, the transparent laminated films of the examples are excellent in optical characteristics and writing quality, whereas the transparent laminated films of Comparative Examples 1 to 3 are not good in writing quality. The transparent laminated film has low optical properties.

  Furthermore, the graph of the friction coefficient with respect to the operating distance when the pen is slid on the transparent laminated films of Examples 1 to 9 and Comparative Examples 1 to 4 is shown in FIGS. FIG. 14 is a graph of the friction coefficient with respect to the operating distance when the 6B pencil is slid on the paper, and FIG. 15 is a graph of the friction coefficient with respect to the operating distance when the HB pencil is slid on the paper. Show. As is clear from the results of FIGS. 1 to 15, the transparent laminated film of the example has a constant friction coefficient profile with respect to the operating distance in the middle of the start of writing of the pen input, and when the pencil is slid on the paper. Similar to profile.

  The transparent laminated film of the present invention can be used for various devices that are input using a pen, such as PCs, televisions, mobile phones (smartphones), electronic paper, gaming machines, mobile devices, watches, calculators, etc. Pen input type touch panel used in combination with a display device (liquid crystal display device, plasma display device, organic or inorganic EL display device, etc.) in the display section of the device (particularly, a projected capacitive touch panel employing an ITO grid method) Display), and pointing devices for computers such as pen tablets.

  Above all, because it is possible to input with a plastic pen with a writing feel like a pencil on paper, it can be displayed on a pen input type touch panel display such as a smartphone, mobile phone, electronic paper, tablet PC, pen tablet, game machine, PC. It is useful, especially because it has excellent transparency and writing quality, it is particularly useful for high-resolution TVs with a 4K TV display equipped with a touch panel, and for high-resolution pen input devices used in the construction and medical fields. It is.

Claims (7)

A base material layer, an adhesive layer laminated on one surface of the base material layer and containing an adhesive and fine particles having an average particle size of 30 to 280 μm, and a cover laminated on the adhesive layer and containing a transparent resin A transparent laminated film comprising a layer and a hard coat layer laminated on the cover layer, wherein the pressure-sensitive adhesive has an elastic modulus of 10 to 3000 Pa, and the elastic modulus of the fine particles is that of the pressure-sensitive adhesive. A transparent laminated film for pen input devices that is larger than the elastic modulus. The transparent laminated film for pen input devices according to claim 1, wherein the weight ratio of the pressure-sensitive adhesive and the fine particles is the former / the latter = 90/10 to 50/50. The transparent laminated film for pen input devices according to claim 1 or 2, wherein the adhesive layer has an average thickness of 0.9 to 1.1 times the average particle size of the fine particles. The transparent laminated film for pen input devices according to claim 1, wherein the cover layer has an average thickness of 9 to 100 μm and the hard coat layer has an average thickness of 1 to 10 μm. The transparent laminated film for pen input devices according to any one of claims 1 to 4, wherein the CV value of the particle diameter of the fine particles is 35% or less. The arithmetic average roughness Ra of the hard coat layer surface is 0.1 µm or less, The transparent laminated film for pen input devices according to any one of claims 1 to 5. 2. The transmitted image sharpness measured by an image clarity measuring device using an optical comb having a width of 0.5 mm is 80% or more, having a haze of 5% or less, a total light transmittance of 85% or more. The transparent laminated film for pen input devices in any one of -6.

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