Writing feel improvement sheet

Abstract

To provide a writability improvement sheet that is excellent in writability with a touch pen and has antiviral properties.SOLUTION: A writability improvement sheet 1 comprises a substrate 11 and a writability improvement layer 12 with which a touch pen is brought into contact. The writability improvement layer 12 contains an antiviral agent. When, in the writability improvement sheet 1, a pen tip of a touch pen having a hard felt core with a pen tip diameter of 0.5 mm is brought into contact with a surface of the writability improvement layer 12 in a vertical direction under a pressure condition of a 3.92 N load, resistance of the pen tip is measured while the pen tip is moved in one arbitrary direction parallel to the surface of the writability improvement layer 12 at a speed of 100 mm / min, and an obtained moving distance-pen tip resistance chart is Fourier transformed, the number of peaks at an amplitude of 1.5 or more in a frequency range of 1-2 Hz acquired from a frequency-amplitude chart obtained through the transformation is 3 to 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a writing feel improving sheet having antiviral properties.

Background Art

[0002] In recent years, in various electronic devices, an image display device (touch panel) with a position detection function that combines a display device and an input means has been widely used. In such a touch panel, in addition to those that are input by a finger, there are those that are input by a touch pen. With a touch pen, a finer and more accurate input operation than with a finger is possible. However, usually, the display module of the touch panel is hard. Therefore, the writing feel with a touch pen is hardly good, unlike the writing feel when writing on paper with a writing instrument.

[0003] In order to solve the problem of the writing feel with a touch pen on a touch panel, it has been considered to attach a film for improving the writing feel (hereinafter, may be referred to as a "writing feel improving film" or a "writing feel improving sheet") to the outermost surface of the touch panel. As such a writing feel improving film, for example, Patent Document 1 includes a transparent base film and linear convex portions that form a mesh structure on at least one surface of the transparent base film, has a plurality of sections in which the mesh structure is regularly arranged, and the linear convex portions occupy 5 to 80% of the entire surface area of the touch film, and discloses a touch film.

[0004] By the way, recently, a pandemic of the novel coronavirus (SARS-CoV-2) infection (COVID-19) has occurred and has become a major problem worldwide. When a virus adheres to the surface of a touch panel, if the surface of the touch panel is touched with a finger, the virus may enter the human body through the finger and cause infection. Therefore, it is desirable to impart antiviral properties to the surface of the touch panel.

[0005] Patent Document 2 and Patent Document 3 disclose non-woven fabrics, knitted fabrics, sheets, etc. having antiviral properties, but their application to optical uses is not considered. On the other hand, Patent Document 4 discloses an antiviral member intended for application to various uses.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] Although the application targets of the antiviral member of Patent Document 4 include optical uses, it is not sufficient as a specific study assuming use on the outermost surface of a display device or the like.

[0008] The present invention has been made in view of such a situation, and an object thereof is to provide a writing feeling improvement sheet that is excellent in writing feeling with a touch pen and has antiviral properties.

Means for Solving the Problems

[0009] In order to achieve the above object, firstly, the present invention provides a writing feel improving sheet including a base material and a writing feel improving layer that comes into contact with a touch pen, wherein the writing feel improving layer contains an antiviral agent, and with respect to the surface of the writing feel improving layer that comes into contact with the touch pen, the tip of a touch pen with a hard felt core having a pen tip diameter of 0.5 mm is brought into contact vertically under a pressing condition of a load of 3.92 N, and while moving the pen tip at a speed of 100 mm / min in an arbitrary one direction parallel to the surface of the writing feel improving layer, the pen tip resistance is measured, the obtained chart of moving distance - pen tip resistance is subjected to Fourier transform, and the number of peaks with an amplitude of 1.5 or more in the frequency range of 1 to 2 Hz obtained from the converted frequency - amplitude chart is 3 or more and 20 or less. (Invention 1).

[0010] In the above invention (Invention 1), since the writing feel improving layer contains an antiviral agent, it has antiviral properties. Further, by having the above physical properties related to the writing feel, it has excellent writing feel with a touch pen.

[0011] In the above invention (Invention 1), after bringing the tip of a touch pen having a pen tip diameter of 0.5 mm into contact with the surface of the writing feel improving layer that comes into contact with the touch pen, a load of 200 g is applied to the touch pen, and while maintaining the angle formed between the touch pen and the surface of the writing feel improving layer at 45°, when the touch pen is linearly slid at a speed of 1.6 mm / second, the coefficient of kinetic friction is preferably 0.10 or more and 0.50 or less. (Invention 2).

[0012] In the above inventions (Inventions 1 and 2), after bringing the tip of a touch pen having a pen tip diameter of 0.5 mm into contact with the surface of the writing feel improving layer that comes into contact with the touch pen, a load of 200 g is applied to the touch pen, and while maintaining the angle formed between the touch pen and the surface of the writing feel improving layer at 45°, when the touch pen is linearly slid at a speed of 1.6 mm / second, the coefficient of static friction is preferably 0.10 or more and 0.50 or less. (Invention 3).

[0013] In the above inventions (Inventions 1 to 3), it is preferable that the writing feel improving layer is a layer formed by curing a coating composition containing a curable component and the antiviral agent (Invention 4).

[0014] In the above inventions (Inventions 1 to 4), it is preferable that the antiviral agent is an organic filler (Invention 5).

Advantages of the Invention

[0015] The writing feel improving sheet according to the present invention is excellent in the writing feel with a touch pen and has antiviral properties.

Brief Description of the Drawings

[0016]

Figure 1

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described. The writing feel improving sheet according to an embodiment of the present invention is a sheet that constitutes the outermost layer of a touch panel on which a touch pen is used, and includes a base material and a writing feel improving layer that comes into contact with the touch pen. Preferably, as shown in FIG. 1, the writing feel improving sheet 1 according to the present embodiment includes a base material 11 and a writing feel improving layer 12 provided on one surface side of the base material 11. The writing feel improving layer 12 contains an antiviral agent.

[0018] In the writing feel improvement sheet 1 according to the present embodiment, with respect to the surface of the writing feel improvement layer 12 that the tip of the touch pen contacts, the tip of a touch pen with a hard felt core having a pen tip diameter of 0.5 mm is brought into vertical contact under a pressing condition of a load of 3.92 N, and while moving it at a speed of 100 mm / min in an arbitrary one direction parallel to the surface of the writing feel improvement layer 12, the pen tip resistance is measured. The obtained chart of the moving distance - pen tip resistance is subjected to Fourier transform, and the number of peaks (amplitude numbers) with an amplitude of 1.5 or more in the frequency range of 1 to 2 Hz, which is obtained from the converted frequency - amplitude chart, is preferably 3 or more and 20 or less (the physical properties regarding the amplitude by this pen sliding test may be hereinafter referred to as "writing feel physical properties"). The Fourier transform is to be performed using software (manufactured by Microsoft Corporation, product name "Excel" (registered trademark)). Further, the "pen tip resistance" refers to the resistance applied to the pen tip when moving the touch pen under the above conditions.

[0019] The writing feel improvement sheet 1 according to the present embodiment has antiviral properties because the writing feel improvement layer 12 contains an antiviral agent. Further, the writing feel improvement sheet 1 has excellent writing feel by the touch pen because it has the above writing feel physical properties. The antiviral agent contained in the writing feel improvement layer 12 is usually in the form of fine particles and also has the effect of imparting the above writing feel physical properties.

[0020] In the writing feel improvement sheet 1 according to the present embodiment, in particular, since the writing feel improvement layer 12 contains an antiviral agent and the number of peaks of the amplitude is within the above range, a preferable pen tip flow feeling and pen tip catching feeling are imparted to the writing feel by the touch pen. These feelings combine to make the writing feel of the touch pen closer to the feeling when writing on paper with a pen and become excellent.

[0021] Stipulating the amplitude in the range of 1 to 2 Hz of the frequency is because, when considering the vibration during writing as a superposition of a plurality of vibrations having various frequencies, the inventors empirically found that the characteristic vibration recognized by people as "writing feel" is the vibration in the range of 1 to 2 Hz of the frequency.

[0022] As for the touch pen, for example, in addition to a touch pen with a hard felt core having a pen tip diameter of 0.1 to 5 mm, a touch pen with a polyacetal core can be used, and the above effects can be obtained regardless of which touch pen is used. Also, the "pen" used as the standard for writing feel in this specification includes ballpoint pens, felt-tip pens, fountain pens, etc., but preferably a fountain pen is used as the standard.

[0023] From the perspective of the writing feel by the touch pen, the number of peaks (amplitude number) of the above amplitude is preferably 4 or more, more preferably 5 or more, particularly preferably 6 or more, and even more preferably 8 or more. Also, the number of peaks (amplitude number) is preferably 18 or less, more preferably 15 or less, particularly preferably 13 or less, and even more preferably 10 or less.

[0024] The specific method for obtaining the above-mentioned chart of moving distance (mm) - pen tip resistance force (mN) is as shown in the test examples described later.

[0025] In the writing feel improvement sheet 1 according to the present embodiment, after bringing the pen tip of a touch pen having a pen tip with a diameter of 0.5 mm into contact with the surface of the writing feel improvement layer 12 that the touch pen contacts, a load of 200 g is applied to the touch pen, and while maintaining the angle formed by the touch pen and the surface of the writing feel improvement layer 12 at 45°, when the touch pen is linearly slid at a speed of 1.6 mm / second, the coefficient of kinetic friction is preferably 0.10 or more, more preferably 0.12 or more, particularly preferably 0.14 or more, and further preferably 0.17 or more. Also, the coefficient of kinetic friction is preferably 0.50 or less, more preferably 0.40 or less, particularly preferably 0.30 or less, and further preferably 0.23 or less. When the coefficient of kinetic friction is within the above range, the writing feel by the touch pen becomes more excellent.

[0026] Also, in the writing feel improvement sheet 1 according to the present embodiment, after bringing the pen tip of a touch pen having a pen tip with a diameter of 0.5 mm into contact with the surface of the writing feel improvement layer 12 that the touch pen contacts, a load of 200 g is applied to the touch pen, and while maintaining the angle formed by the touch pen and the surface of the writing feel improvement layer 12 at 45°, when the touch pen is linearly slid at a speed of 1.6 mm / second, the coefficient of static friction is preferably 0.10 or more, more preferably 0.12 or more, particularly preferably 0.14 or more, and further preferably 0.18 or more. Also, the coefficient of static friction is preferably 0.50 or less, more preferably 0.40 or less, particularly preferably 0.30 or less, and further preferably 0.25 or less. When the coefficient of static friction is within the above range, the writing feel by the touch pen becomes more excellent.

[0027] Note that the specific measurement methods of the above coefficient of kinetic friction and coefficient of static friction are as shown in the test examples described later.

[0028] 1. Each element 1-1. Base material The base material 11 may be appropriately selected from those suitable for a touch panel used with a touch pen, and preferably, a plastic film having good affinity with the writing feel improvement layer 12 is selected. However, the base material 11 may be glass.

[0029] Examples of such plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene film and polypropylene film; cellophane; diacetyl cellulose film; triacetyl cellulose film; acetyl cellulose butyrate film; polyvinyl chloride film; polyvinylidene chloride film; polyvinyl alcohol film; ethylene-vinyl acetate copolymer film; polystyrene film; polycarbonate film; polymethylpentene film; polysulfone film; polyetheretherketone film; polyethersulfone film; polyetherimide film; fluororesin film; polyamide film; acrylic resin film; polyurethane resin film; norbornene-based polymer film; cyclic olefin-based polymer film; cyclic conjugated diene-based polymer film; vinyl alicyclic hydrocarbon polymer film; or laminated films thereof. Among them, in combination with the aforementioned writing feel improvement layer 12, polyethylene terephthalate film, polycarbonate film, norbornene-based polymer film, etc. that can maintain the writing feel of the touch pen well are preferable, and polyethylene terephthalate film is particularly preferable.

[0030] In addition, in the above-mentioned base material 11, for the purpose of improving the adhesion with the layer provided on its surface (such as the writing feel improvement layer 12, the adhesive layer described later, etc.), if desired, surface treatment can be performed on one or both sides by primer treatment, oxidation method, roughening method, etc. Examples of the oxidation method include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone-ultraviolet treatment, etc., and examples of the roughening method include sandblasting method, solvent treatment method, etc. These surface treatment methods are appropriately selected according to the type of the base material 11. As an example, a plastic film, particularly a polyethylene terephthalate film, on which an easy-adhesion layer is formed by primer treatment is preferably used.

[0031] The thickness of the base material 11 is not particularly limited, but considering the use in touch panels, it is preferably 25 μm or more, particularly preferably 38 μm or more, and even more preferably 50 μm or more. Also, the thickness of the base material 11 is preferably 500 μm or less, particularly preferably 400 μm or less, and even more preferably 300 μm or less.

[0032] 1-2. Writing feel improvement layer (1) Materials of the writing feel improvement layer The writing feel improvement layer 12 of the writing feel improvement sheet 1 in the present embodiment may be formed of any material as long as it contains an antiviral agent and satisfies the above-described writing feel physical properties, but is preferably formed by curing the coating composition C described below. According to the coating composition C, it is easy to form the writing feel improvement layer 12 that satisfies the above-mentioned writing feel physical properties, and it is possible to form the writing feel improvement layer 12 having antiviral properties.

[0033] The coating composition C in the present embodiment preferably contains a curable component and an antiviral agent.

[0034] (1-1) Curable component The curable component is a component that cures by a trigger such as active energy rays or heat, and examples thereof include an active energy ray curable component, a thermosetting component, and the like. In the present embodiment, from the viewpoints of the hardness of the texture improvement layer 12 to be formed and the heat resistance of the base material 11 (plastic film), it is preferable to use an active energy ray curable component.

[0035] As the active energy ray curable component, those that cure by irradiation with active energy rays and do not inhibit the antiviral action by the antiviral agent are preferable.

[0036] Specific examples of the active energy ray curable component preferably include polyfunctional (meth)acrylate monomers, (meth)acrylate prepolymers, active energy ray curable polymers, and the like. Among them, polyfunctional (meth)acrylate monomers or (meth)acrylate prepolymers are more preferable. The polyfunctional (meth)acrylate monomers and (meth)acrylate prepolymers may be used alone or in combination. In the present specification, (meth)acrylate means both acrylate and methacrylate. The same applies to other similar terms.

[0037] Examples of the polyfunctional (meth)acrylate monomers include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate and other polyfunctional (meth)acrylates. These may be used alone or in combination of two or more.

[0038] Examples of the (meth)acrylate prepolymers include prepolymers such as polyester acrylate-based, epoxy acrylate-based, urethane acrylate-based, polyol acrylate-based and the like.

[0039] The polyester acrylate-based prepolymer can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth)acrylic acid.

[0040] Epoxy acrylate prepolymers can be obtained, for example, by reacting (meth)acrylic acid with the oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolac type epoxy resin to effect esterification.

[0041] Urethane acrylate prepolymers can be obtained, for example, by esterifying a polyurethane oligomer obtained by the reaction of a polyether polyol or polyester polyol with a polyisocyanate with (meth)acrylic acid.

[0042] Polyol acrylate prepolymers can be obtained, for example, by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

[0043] The above prepolymers may be used alone or in combination of two or more.

[0044] (1-2) Antiviral agent The antiviral agent may be any agent that can inactivate a desired virus. The target virus may be an enveloped virus or a non-enveloped virus. Examples of enveloped viruses include influenza virus, SARS-CoV-2, herpes virus, rubella virus, hepatitis B virus, hepatitis C virus, AIDS virus, etc. Examples of non-enveloped viruses include norovirus, rotavirus, poliovirus, adenovirus, feline calicivirus, etc.

[0045] As the antiviral agent, particulate ones are preferred, whereby the writing texture property described above can be easily achieved by the contribution of the antiviral agent. Examples of the antiviral agent include inorganic antiviral agents and organic antiviral agents. However, from the viewpoint of the ease of satisfying the writing texture property described above, it is preferable to use an organic antiviral agent, particularly a particulate organic antiviral agent. The antiviral agent may be used alone or in combination of two or more.

[0046] Examples of the organic antiviral agent include those composed of an antiviral group and a resin matrix. Specific examples of the antiviral group include an anionic group, a cationic group, an ether group, etc. Examples of the anionic group include a sulfonic acid group, a phosphoric acid group, a carboxyl group, a hydroxyl group, a nitro group, etc. Examples of the cationic group include a quaternary amino group, etc. Examples of the ether group include an alkyl ether group such as an ethyl ether group and a propyl ether group.

[0047] The resin matrix is preferably a polymer of a monomer having a vinyl group. Examples of the monomer having a vinyl group include styrene, (meth)acrylate, divinylbenzene, trivinylbenzene, etc. Further, from the viewpoint of improving the crosslinking degree of the resin matrix, a polyfunctional monomer etc. may be included as a monomer constituent. By polymerizing these monomers having a vinyl group to form a three-dimensional network structure, it is formed into a shape such as the aforementioned particulate shape.

[0048] The average particle size of the particulate antiviral agent is preferably 0.5 μm or more, more preferably 1.0 μm or more, particularly preferably 1.5 μm or more, and even more preferably 2.5 μm or more. Also, the average particle size of the antiviral agent is preferably 10 μm or less, more preferably 8.0 μm or less, particularly preferably 6.0 μm or less, and even more preferably 5.0 μm or less. Thereby, the antiviral property is likely to be exhibited well, and the above-described writing texture property is likely to be more satisfied. Note that the average particle size of the antiviral agent is measured by the laser diffraction method.

[0049] The content of the antiviral agent in the writing texture improving layer 12 (coating composition C) is preferably 1.0% by mass or more, more preferably 3.0% by mass or more, particularly preferably 5.0% by mass or more, and even more preferably 9.0% by mass or more. Also, the content of the antiviral agent is preferably 40% by mass or less, more preferably 30% by mass or less, particularly preferably 25% by mass or less, and even more preferably 20% by mass or less. When the content of the antiviral agent is within the above range, suitable antiviral property can be exhibited, and the above-described writing texture property is likely to be more satisfied.

[0050] The content of the antiviral agent with respect to 100 parts by mass of the curable component is preferably 1.0 part by mass or more, more preferably 3.0 parts by mass or more, particularly preferably 5.0 parts by mass or more, and even more preferably 10 parts by mass or more. Also, the content of the antiviral agent with respect to 100 parts by mass of the curable component is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, particularly preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less. When the content of the antiviral agent is within the above range, suitable antiviral property can be exhibited, and the above-described writing texture property is likely to be more satisfied.

[0051] (1-3) Filler Coating composition C preferably contains fillers other than the antiviral agent. Thereby, the above-described writing texture property is more easily satisfied, and the antiglare property is imparted to the writing texture improvement layer 12. Examples of the filler include inorganic fine particles such as silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, and titanium dioxide; organic fine particles such as acrylic resin, polystyrene resin, polyethylene resin, and epoxy resin; and fine particles composed of a silicon-containing compound having an intermediate structure between inorganic and organic (for example, Tospearl series manufactured by Momentive Performance Materials Japan Co., Ltd., which are fine particles of silicone resin). These fillers may be used alone or in combination of two or more.

[0052] Examples of the fine particles composed of the above acrylic resin include those composed of a homopolymer of methyl methacrylate, a copolymer of methyl methacrylate and monomers such as vinyl acetate, styrene, methyl acrylate, and ethyl (meth)acrylate.

[0053] The shape of the filler may be regular such as spherical, or may be irregular with no specific shape. From the viewpoint of improving the writing texture, it is preferable to use irregular inorganic fine particles (for example, irregular silica).

[0054] The average particle size of the filler is more preferably 0.3 μm or more, particularly preferably 0.5 μm or more, and even more preferably 1.0 μm or more. Also, the average particle size of the filler is preferably 10 μm or less, more preferably 8.0 μm or less, particularly preferably 5.0 μm or less, and even more preferably 3.0 μm or less. When the average particle size of the filler is within the above range, the above-described writing texture property is more easily satisfied, and the antiglare property is exhibited well. Also, the inhibition of the antiviral action by the antiviral agent is suppressed. Note that the average particle size of the filler is measured by the centrifugal sedimentation light transmission method.

[0055] The content of the filler in the writing feeling improvement layer 12 (coating composition C) is preferably 1.0 part by mass or more, more preferably 3.0 parts by mass or more, particularly preferably 5.0 parts by mass or more, and still more preferably 10 parts by mass or more with respect to 100 parts by mass of the curable component. Further, the content is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, particularly preferably 30 parts by mass or less, and still more preferably 20 parts by mass or less. When the content of the filler is within the above range, the above-described writing feeling properties are more easily satisfied, and the antiglare property is favorably exhibited. Further, the inhibition of the antiviral action by the antiviral agent is suppressed.

[0056] (1-4) Sol component The coating composition C preferably contains a sol component. Examples of the sol component include those in which fine particles are in the form of an organosol (colloidal). Preferred examples of the fine particles include inorganic fine particles such as silica, and for example, it is used as an organosilica sol. The fine particles may have a functional group such as a (meth)acryloyl group or a silanol group bonded to the surface.

[0057] The average particle size of the fine particles as the sol component is preferably less than 300 nm, more preferably 100 nm or less, particularly preferably 80 nm or less, and still more preferably 40 nm or less. Further, the average particle size is preferably 1 nm or more, more preferably 4 nm or more, particularly preferably 8 nm or more, and still more preferably 10 nm or more. When the average particle size is within the above range, the above-described writing feeling properties are more easily satisfied. Further, the inhibition of the antiviral action by the antiviral agent is suppressed. The average particle size of the inorganic fine particles is measured by the centrifugal sedimentation light transmission method.

[0058] The content of the sol component in the writing feel improving layer 12 (coating composition C) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, particularly preferably 10 parts by mass or more, and further preferably 20 parts by mass or more with respect to 100 parts by mass of the curable component. Also, the content is preferably 300 parts by mass or less, more preferably 200 parts by mass or less, particularly preferably 100 parts by mass or less, and further preferably 50 parts by mass or less. Thereby, the above-described writing feel properties are more easily satisfied. Also, the inhibition of the antiviral action by the antiviral agent is suppressed.

[0059] (1-5) Photoinitiator When ultraviolet rays are used for curing the active energy ray curable component, the coating composition C preferably contains a photoinitiator. By containing a photoinitiator, the active energy ray curable component can be efficiently polymerized, and the polymerization curing time and the irradiation amount of ultraviolet rays can be reduced.

[0060] Examples of such photoinitiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin - n - butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2 - dimethoxy - 2 - phenylacetophenone, 2,2 - diethoxy - 2 - phenylacetophenone, 2 - hydroxy - 2 - methyl - 1 - phenylpropan - 1 - one, 1 - hydroxycyclohexyl phenyl ketone, 2 - methyl - 1 - [4 - (methylthio)phenyl] - 2 - morpholino - propan - 1 - one, 4 - (2 - hydroxyethoxy)phenyl - 2 - (hydroxy - 2 - propyl)ketone, benzophenone, p - phenylbenzophenone, 4,4’ - diethylaminobenzophenone, dichlorobenzophenone, 2 - methylanthraquinone, 2 - ethylanthraquinone, 2 - tert - butylanthraquinone, 2 - aminoanthraquinone, 2 - methylthioxanthone, 2 - ethylthioxanthone, 2 - chlorothioxanthone, 2,4 - dimethylthioxanthone, 2,4 - diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p - dimethylaminobenzoic acid ester, oligo[2 - hydroxy - 2 - methyl - 1[4 - (1 - methylvinyl)phenyl]propanone], 2,4,6 - trimethylbenzoyl - diphenyl - phosphine oxide, and the like. These may be used alone or in combination of two or more.

[0061] The content of the photoinitiator in the coating composition C is preferably at least 0.01 part by mass, particularly preferably at least 0.1 part by mass, and more preferably at least 1 part by mass, based on 100 parts by mass of the active energy ray - curable component. Also, the upper limit is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

[0062] (1 - 6) Antifouling agent The coating composition C according to this embodiment preferably contains an antifouling agent. Thereby, the writing feeling improvement layer 12 formed has excellent antifouling properties, and it is possible to make it difficult for fingerprints and dirt to adhere.

[0063] Examples of the antifouling agent include silicone-based antifouling agents, fluorine-based antifouling agents, and acrylic-based antifouling agents. Among them, it is preferable to use a fluorine-based antifouling agent from the viewpoint of making it difficult for fingerprints and dirt to adhere. As the fluorine-based antifouling agent, a fluorine-based resin having a (meth) acrylate group polymerizable with a polyfunctional (meth) acrylate-based monomer or (meth) acrylate-based prepolymer as a binder resin is preferable.

[0064] The content of the antifouling agent in the writing feeling improvement layer 12 (coating composition C) is preferably 0.01 part by mass or more, particularly preferably 0.1 part by mass or more, and more preferably 0.5 part by mass or more with respect to 100 parts by mass of the curable component. Further, the content is preferably 30 parts by mass or less, particularly preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

[0065] (1-7) Levelling agent The coating composition C according to this embodiment preferably contains a levelling agent. Thereby, the writing feeling improvement layer 12 formed has no streak-like defects or unevenness, has a uniform film thickness, and exhibits excellent optical properties and appearance.

[0066] Examples of the levelling agent include silicone-based levelling agents, fluorine-based levelling agents, acrylic-based levelling agents, and vinyl-based levelling agents. Among them, from the viewpoints of levelling property and compatibility with other components, a silicone-based levelling agent or a fluorine-based levelling agent is preferable. Note that the levelling agent may be used alone or in combination of two or more.

[0067] The leveling agent may be modified or unmodified. Also, the leveling agent may have a reactive group or may not have a reactive group.

[0068] The content of the leveling agent in the writing feel improving layer 12 (coating composition C) is preferably 0.01 part by mass or more, particularly preferably 0.05 part by mass or more, and still more preferably 0.1 part by mass or more with respect to 100 parts by mass of the curable component. Also, the content is preferably 5.0 parts by mass or less, particularly preferably 3.0 parts by mass or less, and still more preferably 1.0 part by mass or less.

[0069] (1-8) Other components The coating composition C in the present embodiment may contain various additives in addition to the above components. Examples of the various additives include a dispersant, an ultraviolet absorber, an antioxidant, a light stabilizer, an antistatic agent, a silane coupling agent, an anti-aging agent, a thermal polymerization inhibitor, a colorant, a surfactant, a storage stabilizer, a plasticizer, a lubricant, a defoaming agent, and the like.

[0070] (2) Thickness The thickness of the writing feel improving layer 12 is preferably 0.5 μm or more, more preferably 1.0 μm or more, particularly preferably 1.5 μm or more, and still more preferably 2.0 μm or more. This makes it easier to satisfy the aforementioned writing feel physical properties and also enables good antiviral performance. Also, the thickness of the writing feel improving layer 12 is preferably 20 μm or less, more preferably 15 μm or less, particularly preferably 10 μm or less, and still more preferably 5.0 μm or less. This makes it easier to satisfy the aforementioned writing feel physical properties.

[0071] 1-3. Other configurations The writing feel improvement sheet 1 according to this embodiment may include an adhesive layer on the side of the base material 11 opposite to the writing feel improvement layer 12. The adhesive constituting the adhesive layer is not particularly limited, and known adhesives such as acrylic adhesives, rubber adhesives, and silicone adhesives can be used, and it is preferable to use an adhesive having a predetermined transparency.

[0072] Further, when the writing feel improvement sheet 1 according to this embodiment includes the above-described adhesive layer, the writing feel improvement sheet 1 according to this embodiment may have a release film laminated on the surface of the adhesive layer opposite to the base material 11. The release film is not particularly limited as long as it has a desired releasability on its release surface (the surface in contact with the adhesive layer), and known release films such as those in which one side of a resin film is subjected to a release treatment with a release agent can be used.

[0073] 2. Manufacturing method of writing feel improvement sheet The writing feel improvement sheet 1 according to this embodiment can be manufactured by applying a coating liquid containing a coating composition for the writing feel improvement layer 12, preferably the coating composition C, and optionally a solvent, to the base material 11 and curing it to form the writing feel improvement layer 12.

[0074] The solvent can be used for improving coating properties, adjusting viscosity, adjusting solid content concentration, etc., and can be used without particular limitation as long as each component can be dissolved or dispersed. Specific examples of the solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl lactate, and γ-butyrolactone; ethers such as ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), diethylene glycol monobutyl ether (butyl cellosolve), and propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene, and xylene; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone, etc.

[0075] The coating of the coating liquid of the coating composition may be carried out by a conventional method. For example, it may be carried out by a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, or a gravure coating method. After applying the coating liquid of the coating composition, it is preferable to dry the coating film at 40 to 120 °C for about 30 seconds to 5 minutes.

[0076] Here, when the coating composition contains a leveling agent, the coating film formed by applying the coating composition will have no streak-like defects or unevenness, etc. Therefore, a leveling improvement layer 12 with a uniform film thickness and excellent appearance can be formed.

[0077] When the coating composition is curable by active energy rays like the coating composition C, the curing of the coating composition is carried out by irradiating the coating film of the coating composition with active energy rays such as ultraviolet rays and electron beams. The ultraviolet irradiation can be carried out by a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, etc. The irradiation amount of ultraviolet rays is an illuminance of 50 to 1000 mW / cm 2 and a light amount of 50 to 1000 mJ / cm 2The degree is preferable. On the other hand, electron beam irradiation can be performed by an electron beam accelerator or the like, and the irradiation dose of the electron beam is preferably about 10 to 1000 krad.

[0078] Irradiation of the active energy ray to the coating film of the coating composition can be performed in an air atmosphere or an inert gas atmosphere. Depending on the type of the active energy ray curable component, by performing active energy ray irradiation in an inert gas atmosphere, the coating composition can be cured well without being affected by oxygen inhibition.

[0079] Examples of the inert gas include nitrogen, argon, helium, etc. Among them, nitrogen and argon are preferable, and nitrogen is particularly preferable. The oxygen concentration in the inert gas atmosphere is preferably 5% or less, more preferably 3% or less, and particularly preferably 2% or less.

[0080] 3. Physical properties of the writing feel improving sheet, etc. (1) Haze value The haze value of the writing feel improving sheet 1 according to the present embodiment is preferably 5.0% or more, more preferably 8.0% or more, particularly preferably 10% or more, and further preferably 15% or more. Thereby, good antiglare property is imparted. On the other hand, from the viewpoint of visibility of images / videos, the haze value is preferably 60% or less, more preferably 55% or less, particularly preferably 50% or less, and further preferably 45% or less. The method for measuring the haze value is as shown in the test examples described later.

[0081] (2) Total light transmittance The total light transmittance of the writing feel improving sheet 1 according to the present embodiment is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. When the total light transmittance is the above value, the transparency is very high, and it is particularly suitable for optical applications (for display bodies). The method for measuring the total light transmittance is as shown in the test examples described later.

[0082] (3) Image sharpness The total value of the image sharpness (%) of the optical combs with thicknesses of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, measured in accordance with JIS K7374:2007 for the writing feel improvement sheet 1, is preferably 30 or more, more preferably 50 or more, particularly preferably 100 or more, and even more preferably 150 or more. This makes the visibility of images and videos on the display good.

[0083] On the other hand, the total value of the image sharpness (%) is preferably 480 or less, more preferably 450 or less, particularly preferably 400 or less, and even more preferably 300 or less. This enables the writing feel properties to be exhibited well while maintaining good visibility of images and videos on the display.

[0084] Here, the image sharpness is measured by passing the amount of parallel light transmitted through the test specimen through an optical comb having a transmission portion and a light-shielding portion. The smaller the widths (comb widths) of the transmission portion and the light-shielding portion in the optical comb, the higher the image sharpness with higher fineness. The image sharpness is measured in accordance with the transmission method of JIS K7374:2007. The specific measurement method is as shown in the test examples described later.

[0085] (4) 60° specular gloss The 60° specular gloss (gloss value) of the surface of the writing feel improvement layer 12 in contact with the touch pen of the writing feel improvement sheet 1 according to the present embodiment is preferably 30% or more, more preferably 50% or more, particularly preferably 70% or more, from the viewpoint of preventing whitening. Also, the 60° specular gloss of the writing feel improvement sheet 1 is preferably 150% or less, particularly preferably 110% or less, and even more preferably 90% or less, from the viewpoint of ease of satisfying the writing feel properties. The measurement method of the 60° specular gloss in this specification is as shown in the test examples described later.

[0086] (5) Pencil hardness The pencil hardness of the surface of the writing feel improvement sheet 1 according to this embodiment is preferably F or higher, particularly preferably H or higher, and even more preferably 2H or higher. By having such a pencil hardness in the writing feel improvement layer 12, the surface of the writing feel improvement sheet 1 has sufficient hardness and can exhibit excellent scratch resistance. The upper limit value of the above pencil hardness is not particularly limited, but is preferably 6H or lower. The method for measuring the pencil hardness is as shown in the test examples described later.

[0087] 4. Use of the writing feel improvement sheet The writing feel improvement sheet 1 according to this embodiment can be used as a sheet constituting the outermost layer of a touch panel (image display device with position detection function) where a touch pen is used. Specifically, it is preferably laminated on a cover material in a touch panel having a display module such as a liquid crystal (LCD) module, a light emitting diode (LED) module, an organic electroluminescence (organic EL) module, or a touch sensor. The lamination of the writing feel improvement sheet 1 on the cover material is preferably performed by sticking through the adhesive layer described above.

[0088] In addition, the touch pen used for the writing feel improvement sheet 1 according to this embodiment is not particularly limited, and conventionally known ones can be used. For example, as the touch pen, those having a pen tip made of polyacetal, those having a pen tip made of hard felt, those having a pen tip made of elastomer, etc. can be used. Also, the shape of the pen tip of the touch pen is not particularly limited and can be appropriately selected from a disk shape, a circular shape, a polygonal shape, etc. However, from the viewpoint of obtaining the vibration feeling when writing with a ballpoint pen, a circular shape is preferable. When the shape of the pen tip of the touch pen is circular, the diameter of the pen tip is preferably 0.1 mm or more, particularly preferably 0.2 mm or more, and even more preferably 0.3 mm or more. Also, the above diameter is preferably 5 mm or less, particularly preferably 2 mm or less, and even more preferably 1 mm or less.

[0089] 5. Touch Panel with Writing Feeling Improvement Sheet By laminating the writing feeling improvement sheet according to the above-described embodiment on the touch panel, a touch panel with a writing feeling improvement sheet (including the concept of a display body provided with a touch panel member) can be obtained. Specifically, the touch panel with a writing feeling improvement sheet includes a writing feeling improvement sheet having a touch pen contact surface with which a touch pen comes into contact, and a touch panel. On the display surface side of the touch panel, the surface side opposite to the touch pen contact surface in the writing feeling improvement sheet is laminated. The writing feeling improvement sheet may be directly laminated on the display surface of the touch panel, or may be laminated on the display surface side of the touch panel via other members or layers.

[0090] The type and method of the touch panel are not particularly limited. For example, a capacitive touch panel, an electromagnetic induction touch panel, a resistive film touch panel, a surface acoustic wave (ultrasonic) touch panel, an infrared touch panel, etc. can be used. Among these, from the viewpoint of being easy to reproduce excellent writing feeling, a capacitive touch panel is preferable. Considering the reproducibility of characters etc. by a touch pen, a capacitive touch panel having electromagnetic induction is particularly preferable. The specific configuration etc. of the capacitive and electromagnetic induction touch panels are not particularly limited, and conventionally known ones can be used.

[0091] The above-described embodiments are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[0092] For example, another layer may be interposed between the base material 11 and the writing feeling improvement layer 12 in the writing feeling improvement sheet 1. Further, another layer such as a hard coat layer may be provided on the surface of the base material 11 on the side opposite to the writing feeling improvement layer 12.

Example

[0093] Hereinafter, the present invention will be described in more detail by way of examples and the like, but the scope of the present invention is not limited to these examples and the like.

[0094] [Example 1] 100 parts by mass of dipentaerythritol hexaacrylate as an active energy ray-curable component, 30 parts by mass of an organosilica sol (manufactured by Nissan Chemical Industries, Ltd., product name "MIBK-ST", average particle size 10 nm) as a sol component (expressed as a solid content conversion value. Hereinafter, the same shall apply to other components), 10 parts by mass of an anionic organic filler (A1; manufactured by Sekisui Materials Co., Ltd., product name "Wiltecure VM", average particle size 3.0 μm) as an antiviral agent, 5.0 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator, 0.5 parts by mass of a fluorine-based resin (manufactured by DIC Corporation, product name "Megafac RS-90") as an antifouling agent, and 0.2 parts by mass of polydimethylsiloxane (manufactured by Toray Dow Corning Co., Ltd., product name "SH28") as a silicone-based leveling agent were mixed in propylene glycol monomethyl ether to obtain a coating liquid of a coating composition. The coating composition of this system (the content of the antiviral agent may be different) is denoted as "C1" in Table 1.

[0095] The coating liquid of the coating composition obtained above was applied to the surface of a polyester film with an easy-adhesion layer (manufactured by Toyobo Co., Ltd., product name "Cosmo Shine A4300", thickness: 125 μm) on the side of the easy-adhesion layer as a substrate, and dried at 70 °C for 1 minute.

[0096] Next, under a nitrogen atmosphere, ultraviolet rays were irradiated under the following conditions using an ultraviolet irradiation device (manufactured by Eye Graphics Co., Ltd., product name "Eye Gratage ECS-401GX type") to form a writing feeling improvement layer with a thickness of 5.0 μm on the substrate, and a writing feeling improvement sheet was obtained. [Ultraviolet Irradiation Conditions] · Light source: High-pressure mercury lamp · Lamp power: 2 kW · Conveyor speed: 4.23 m / min · Illuminance: 300 mW / cm 2 · Light quantity: 250 mJ / cm2

[0097] 〔Examples 2 to 4〕 A taste improvement sheet was produced in the same manner as in Example 1, except that the type and blending amount of the antiviral agent were changed as shown in Table 1.

[0098] 〔Example 5〕 100 parts by mass of dipentaerythritol hexaacrylate as an active energy ray curable component, 40 parts by mass of an organosilica sol (manufactured by Nissan Chemical Industries, Ltd., product name "MIBK-ST", average particle size 10 nm) as a sol component, 20 parts by mass of amorphous silica fine particles (average particle size 1.5 μm) as a filler, 10 parts by mass of an anionic organic filler (A1; manufactured by Sekisui Materials Co., Ltd., product name "Wiltecker VM", average particle size 3.0 μm) as an antiviral agent, 5.0 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator, 1.0 part by mass of a fluorine-based resin (manufactured by DIC Corporation, product name "MegaFac RS-90") as an antifouling agent, and 0.33 part by mass of polydimethylsiloxane (manufactured by Toray Dow Corning Co., Ltd., product name "SH28") as a silicone-based leveling agent were mixed in propylene glycol monomethyl ether to obtain a coating liquid of a coating composition. The coating composition of this system is designated as "C2" in Table 1.

[0099] Using the coating liquid of the obtained coating composition, a taste improvement sheet was produced in the same manner as in Example 1.

[0100] 〔Comparative Example 1〕 A coating liquid of a coating composition was prepared with the same composition as in Example 5, except that no antiviral agent was blended. The coating composition of this system is designated as "C3" in Table 1.

[0101] Using the coating liquid of the obtained coating composition, a taste improvement sheet was produced in the same manner as in Example 1.

[0102] Here, the details of the abbreviations and the like described in Table 1 are as follows. A1: Anionic organic filler (manufactured by Sekisui Materials Co., Ltd., product name "Wiltecare VM", average particle size 3.0 μm) A2: Ether-based organic filler (manufactured by Sekisui Materials Co., Ltd., product name "Wiltecare IV", average particle size 5.0 μm)

[0103] [Test Example 1] (Measurement of haze value) For the writing feel improvement sheets manufactured in the examples and comparative examples, the haze value (%) was measured in accordance with JIS K7136:2000 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH5000"). The results are shown in Table 2.

[0104] [Test Example 2] (Measurement of total light transmittance) For the writing feel improvement sheets manufactured in the examples and comparative examples, the total light transmittance (%) was measured in accordance with JIS K7361-1:1997 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH5000"). The results are shown in Table 2.

[0105] [Test Example 3] (Measurement of image sharpness) For the writing feel improvement sheets manufactured in the examples and comparative examples, using an imageability measuring instrument (manufactured by Suga Test Instruments Co., Ltd., product name "ICM-10P"), in accordance with the transmission method of JIS K7374:2007, the image sharpness (%) of five types of optical combs (comb width: 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm) was measured, and the total value was calculated. The results are shown in Table 2.

[0106] [Test Example 4] (Measurement of 60° specular gloss) For the writing feel improvement sheets manufactured in the examples and comparative examples, using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd.), the 60° specular gloss (gloss value, %) was measured in accordance with JIS Z8741-1997. The results are shown in Table 2.

[0107] [Test Example 5] (Evaluation of anti-glare property) The surface on the base material side of the writing feel improvement sheets manufactured in the examples and comparative examples was attached to one side of a black plate (manufactured by Yūkō Shōkai Co., Ltd., product name "Acrylite") via a double-sided adhesive sheet. Regarding the laminate of the obtained writing feel improvement sheet and the black plate, a three-wavelength fluorescent lamp was lit above the laminate, and the light was reflected by the writing feel improvement sheet. The reflected light was visually observed, and the antiglare property was evaluated according to the following criteria. The results are shown in Table 2. ◎: The outline of the fluorescent lamp visually recognized by the reflection on the writing feel improvement sheet was blurred. 〇: The outline of the fluorescent lamp visually recognized by the reflection on the writing feel improvement sheet was slightly blurred. ×: The outline of the fluorescent lamp visually recognized by the reflection on the writing feel improvement sheet was not blurred.

[0108] 〔Test Example 6〕(Measurement of Pencil Hardness) Regarding the surfaces of the writing feel improvement sheets manufactured in the examples and comparative examples, the pencil hardness was measured according to JIS K5600. Specifically, on the surface of the writing feel improvement sheet, a test was conducted in which pencils (manufactured by Mitsubishi Pencil Co., Ltd., product name "Mitsubishi Pencil Uni") with different hardnesses of pencil leads were run for 7 mm or more at a load of 750 g and an angle of 45°. This test was conducted 5 times, and the hardness of the pencil lead that did not scratch the film surface 4 times or more was taken as the pencil hardness of the surface of the writing feel improvement sheet. The results are shown in Table 2.

[0109] 〔Test Example 7〕(Evaluation of Scratch Resistance) Regarding the surfaces of the writing feel improvement sheets manufactured in the examples and comparative examples, using #0000 steel wool, 2 it was rubbed 10 cm back and forth 10 times at a load of. The surface of the writing feel improvement sheet was visually confirmed under a three-wavelength fluorescent lamp, and the scratch resistance was evaluated according to the following criteria. The results are shown in Table 2. 〇: There were no scratches. ×: There were scratches.

[0110] 〔Test Example 8〕(Friction Measurement) The surface on the base material side of the writing feel improvement sheets manufactured in the examples and comparative examples was attached to one side of a glass plate (thickness: 1.2 mm) via a double-sided adhesive sheet, and this was used as a measurement sample.

[0111] The above measurement sample was placed on the dedicated carriage for measurement of a static and kinetic friction measuring machine (manufactured by Trinity Lab., product name: "TriboMaster TL201Ts") such that the surface of the writing feel improvement layer side (touch pen contact surface) faced upward. The dedicated carriage for measurement is configured to reciprocate in a predetermined direction while maintaining the horizontality of the installation surface of the measurement sample when using the static and kinetic friction measuring machine.

[0112] Subsequently, the touch pen was fixed to the above static and kinetic friction measuring machine so that the pen tip contacted the touch pen contact surface. At this time, the touch pen was inclined and fixed so that the angle formed by the touch pen and the touch pen contact surface was 45°. Also, the direction of inclination at that time was inclined toward the traveling direction side of the dedicated carriage for measurement and was made parallel to the traveling direction. As the touch pen, a touch pen with a hard felt core (manufactured by Wacom, product name: "ACK-20003", pen tip diameter: 0.5 mm) was used.

[0113] Subsequently, with a load applied to the touch pen under a pressure condition of 200 g, the dedicated carriage for measurement described above was moved at a speed of 1.6 mm / second, causing the touch pen to slide on the touch pen contact surface (sliding distance: 100 mm), and the static friction coefficient and kinetic friction coefficient were derived based on the frictional force measured at that time. The results are shown in Table 2.

[0114] 〔Test Example 9〕(Pen Sliding Test) With respect to the surface of the writing feel improvement layer of the measurement sample obtained in Test Example 8, while the pen tip of a touch pen with a hard felt core (manufactured by Wacom, product name: "ACK-20003", pen tip diameter: 0.5 mm) was brought into contact in the vertical direction (the direction in which the axis of the pen tip is perpendicular to the surface of the writing feel improvement layer) under a pressure condition of 3.92 N, it was moved at a speed of 100 mm / min in an arbitrary one direction parallel to the surface of the writing feel improvement sheet. Similar to Test Example 8, the touch pen was attached to the dedicated carriage for measurement, and by moving the carriage, the touch pen was slid on the writing feel improvement layer.

[0115] The pen tip resistance during movement was measured using a universal testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon"), and a chart of movement distance (mm) - pen tip resistance (mN) was obtained. Then, the obtained chart of movement distance (mm) - pen tip resistance (mN) was subjected to Fourier transform using software (manufactured by Microsoft Corporation, product name "Excel" (registered trademark)) to obtain a frequency (Hz) - amplitude (-) chart. From the said frequency (Hz) - amplitude (-) chart, the number of peaks with an amplitude of 1.5 or more in the frequency range of 1 to 2 Hz was determined. The results are shown in Table 2.

[0116] [Test Example 10] (Sensory Evaluation of Writing Feel) For the surface of the writing feel improvement layer of the measurement sample obtained in Test Example 8, five panelists used a touch pen with a hard felt core (manufactured by Wacom Co., Ltd., product name "ACK-20003", pen tip diameter: 0.5 mm) to perform a simulated predetermined writing task and evaluated the following writing feel. Table 2 shows the evaluation results based on the evaluation by five panelists according to the following criteria. The evaluation of each writing feel was based on the writing feel when writing on five sheets of stacked paper (manufactured by Kokuyo S&T Co., Ltd., product name "Campus Notebook A Ruled No. -201A") using a fountain pen (manufactured by S.T. Dupont, product name "Line D 410674 Black Lacquer & Palladium").

[0117] (1) Pen Tip Flow Feeling The pen tip flow feeling as a writing feel was evaluated according to the following criteria. ◎: It was evaluated that it had a pen tip flow feeling equivalent to that when all five people wrote on paper. ○: It was evaluated that it had a pen tip flow feeling equivalent to that when 3 to 4 out of 5 people wrote on paper. △: It was evaluated that it had a pen tip flow feeling equivalent to that when 1 to 2 out of 5 people wrote on paper. ×: It was evaluated that the pen tip flowed more than when all five people wrote on paper.

[0118] (2) Pen Tip Hooking Feeling The pen tip hooking feeling as a writing feel was evaluated according to the following criteria. ◎: It was evaluated that it has the same pen tip catching feeling as when all 5 people wrote on paper. ○: It was evaluated that it has the same pen tip catching feeling as when 3 to 4 out of 5 people wrote on paper. △: It was evaluated that it has the same pen tip catching feeling as when 1 to 2 out of 5 people wrote on paper. ×: It was evaluated that the pen tip catches more than when all 5 people wrote on paper.

[0119] (3) Scratching sound The scratching sound as the writing feel was evaluated according to the following criteria. ◎: It was evaluated that it has the same scratching sound as when all 5 people wrote on paper. ○: It was evaluated that it has the same scratching sound as when 3 to 4 out of 5 people wrote on paper. △: It was evaluated that it has the same scratching sound as when 1 to 2 out of 5 people wrote on paper. ×: It was evaluated that the scratching sound during writing by all 5 people is insufficient.

[0120] (4) Vibration The vibration as the writing feel was evaluated according to the following criteria. ◎: It was evaluated that it has the same vibration as when all 5 people wrote on paper. ○: It was evaluated that it has the same vibration as when 3 to 4 out of 5 people wrote on paper. △: It was evaluated that it has the same vibration as when 1 to 2 out of 5 people wrote on paper. ×: It was evaluated that the vibration during writing by all 5 people is insufficient.

[0121] [Test Example 11] (Antiviral test) The virus species for the antiviral test were seasonal influenza A virus (with envelope) and feline calicivirus (without envelope). In accordance with ISO 21702, an antiviral test was conducted on the writing feel improvement sheets manufactured in the examples and comparative examples. Specifically, it is as follows.

[0122] A virus suspension with a predetermined concentration was prepared by infecting host cells with a virus and culturing them. The writing feel improvement sheets (5 cm × 5 cm; measurement samples) produced in the examples and comparative examples were placed in a petri dish, 0.4 mL of the virus suspension was placed on the surface of the writing feel improvement sheet, and it was covered with a polyethylene film (4 cm × 4 cm) so that the virus suspension spread over the entire surface of the writing feel improvement sheet.

[0123] After storing the above petri dish in a thermo-hygrostat for a predetermined time, it was eluted with SCDLP medium, and this eluate was serially diluted with EMEM medium. Then, the virus infectivity titer of these dilutions was measured by the plaque assay method. Instead of the writing feel improvement sheet, a polyethylene film (5 cm × 5 cm; standard sample) was used as the target, and the virus infectivity titer was measured in the same manner as above. The difference between the virus infectivity titer of the measured standard sample and the virus infectivity titer of the measurement sample was calculated as a log value, and this was used as the activity value of the antiviral property. The results are shown in Table 2.

[0124]

Table 1

[0125]

Table 2

[0126] As is clear from Table 2, the writing feel improvement sheets produced in the examples showed excellent antiviral properties against both viruses with envelopes and viruses without envelopes. In addition, the writing feel improvement sheets produced in the examples were excellent in the writing feel with a touch pen.

Industrial Applicability

[0127] The writing feel improvement sheet of the present invention is suitably used as the outermost layer of a touch panel on which a touch pen is used.

Explanation of Symbols

[0128] 1... Writing feel improvement sheet 11... Base material 12... Writing feel improvement layer

Claims

1. A writing feel improvement sheet including a base material and a writing feel improvement layer that comes into contact with a touch pen, wherein the writing feel improvement layer contains a particulate organic antiviral agent, the organic antiviral agent is composed of an anionic group as an antiviral group and a resin matrix, the average particle diameter of the particulate organic antiviral agent is 0.5 μm or more and 10 μm or less, with respect to the surface of the writing feel improvement layer that comes into contact with the touch pen, the pen tip of a touch pen with a hard felt core having a pen tip diameter of 0.5 mm is brought into vertical contact under a pressing condition of a load of 3.92 N, and while moving in an arbitrary one direction parallel to the surface of the writing feel improvement layer at a speed of 100 mm / min, the pen tip resistance is measured, the obtained chart of the moving distance - pen tip resistance is subjected to Fourier transform, and the number of peaks with an amplitude of 1.5 or more in the frequency range of 1 to 2 Hz obtained from the converted frequency - amplitude chart is 3 or more and 20 or less A writing feel improvement sheet characterized by the above.

2. With respect to the surface of the writing feel improvement layer that comes into contact with the touch pen, after the pen tip of a touch pen having a pen tip diameter of 0.5 mm is brought into contact, a load of 200 g is applied to the touch pen, and while maintaining the angle formed by the touch pen and the surface of the writing feel improvement layer at 45°, when the touch pen is linearly slid at a speed of 1.6 mm / sec, the coefficient of kinetic friction is 0.10 or more and 0.50 or less. The writing feel improvement sheet according to Claim 1, characterized by this.

3. With respect to the surface of the writing feel improvement layer that comes into contact with the touch pen, after the pen tip of a touch pen having a pen tip diameter of 0.5 mm is brought into contact, a load of 200 g is applied to the touch pen, and while maintaining the angle formed by the touch pen and the surface of the writing feel improvement layer at 45°, when the touch pen is linearly slid at a speed of 1.6 mm / sec, the coefficient of static friction is 0.10 or more and 0.50 or less. The writing feel improvement sheet according to Claim 1 or 2, characterized by this.

4. The sheet for improving writing feel according to any one of claims 1 to 3, wherein the layer for improving writing feel is a layer formed by curing a coating composition containing a curable component and the antiviral agent.

Images