JP2007265100A - Touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel which is excellent in preventing Newton ring when a touch panel is pressed and excellent in durability of a conductive film.
A touch panel according to the present invention is arranged via a spacer S so that the conductive films Da and Db of a pair of panel plates Pa and Pb having conductive films Da and Db face each other. The panel panel Pa on the side to be pressed is a resistive film type touch panel including at least a base material (A) 1, an adhesive layer 2, a base material (B) 3, and a conductive film Da in order, and the pair of panels One or both of the conductive films Da and Db of the plates Pa and Pb have an arithmetic mean roughness (Ra) of 0.07 μm to 0.3 μm and a maximum height (Ry) of 1.5 μm in JIS B0601: 1994. It is provided on the Newton ring prevention layer 4 which is -2.0 micrometers.
[Selection] Figure 1

Description

  The present invention relates to a touch panel used as a transparent switch structure on a display screen such as a CRT or a flat panel display.

  In a resistive film type touch panel in which a pair of panel plates having a conductive film are arranged to face each other through a spacer so that the conductive films face each other, the panel plate on the pressing side is made of a transparent substrate. Touch panels having a hard coat layer on one side and a conductive film on the other side are generally widely used. Such a touch panel has a problem in that Newton's ring occurs due to contact and close contact between the conductive films at the time of input. However, to improve this, either one of the conductive films or There has been proposed a touch panel in which a Newton ring prevention layer (a binder component and fine particles having a fine uneven shape on the surface) is provided on both surfaces, and a conductive film is provided on the upper layer (hereinafter referred to as a general touch panel). Sometimes called a touch panel).

  On the other hand, in the resistive film type touch panel as described above, the touch panel has a structure in which the panel panel to be pressed is bonded to the transparent base material with a hard coat layer via the transparent adhesive layer. Since such a touch panel has an adhesive layer on the panel plate to be pressed, the cushioning effect improves the scratch resistance of the pressed surface of the panel plate, and the panel plate. For this, moderate elastic deformability is imparted to improve the writing feeling with the input pen (Patent Document 1).

JP-A-6-309990 (Claim 2, paragraph number 0007)

  However, even in such a touch panel, there is a problem that Newton rings occur due to contact and close contact between the conductive films at the time of input, and in order to improve this, Newton ring prevention as described above is prevented. When a layer is provided on one or both surfaces of the conductive film, the conductive film is more conductive than the case of using the general touch panel (the panel panel on the pressing side does not have an adhesive layer). As a result, scratches were easily generated on the surface having the conductive film, resulting in a problem in durability.

  Then, this invention aims at providing the touch panel excellent in the durability of a conductive film while being excellent in the Newton ring prevention property at the time of pressing a touch panel.

  In the case where the Newton ring prevention layer is provided on the surface having the conductive film, the present inventors have a touch panel having a structure having a transparent adhesive layer on the panel panel on the pressing side as described above. As a result of earnest research on the problem that the panel panel on the side to be pressed does not have an adhesive layer), the panel board on the side to be pressed is more likely to be damaged due to the difference in the deformation of the panel board when pressed. We found that a difference occurred.

  The touch panel having a transparent pressure-sensitive adhesive layer on the panel plate to be pressed has a pressure-sensitive adhesive layer when pressed. As compared with a touch panel that does not have an adhesive layer on the panel plate, deflection occurs downward about the pressed point. This deflection increases the area of the Newton ring prevention layer in contact with the conductive film when pressed, and the number of convex portions of the Newton ring prevention layer in contact with the conductive film increases. It is considered to be inferior in durability.

  Therefore, the present inventors have reduced the durability of the conductive film even when the area of the Newton ring prevention layer in contact with the conductive film is increased by providing the Newton ring prevention layer having a specific shape. Has been found to be able to be prevented, and the present invention has been completed.

  That is, the touch panel according to the present invention is arranged with a spacer so that the conductive films of a pair of panel boards having a conductive film face each other, and the panel panel on the side to be pressed is at least a base material (A). , A pressure-sensitive adhesive layer, a base material (B), and a resistive film type touch panel sequentially provided with a conductive film, wherein one or both of the pair of panel plates are in accordance with JIS B0601: 1994. The arithmetic average roughness (Ra) is 0.07 μm to 0.3 μm, and the maximum height (Ry) is 1.5 μm to 2.0 μm. .

  Moreover, the touch panel of the present invention is characterized in that the Newton ring prevention layer is made of a binder component and fine particles and is formed by a coating method.

  In the touch panel of the present invention, the binder component comprises an ionizing radiation curable resin composition and another resin component, and the content of the other resin component is 0. 0 in the total solid content in the binder component. It is characterized by being 1 to 15% by weight.

  In the touch panel of the present invention, the glass transition temperature of the other resin component is 50 ° C to 120 ° C.

  In the touch panel of the present invention, the average particle diameter of the fine particles is 0.5 μm to 3.0 μm.

  The touch panel of the present invention is characterized in that a variation coefficient of a particle size distribution of the fine particles is 20% to 80%.

  The touch panel of the present invention is characterized in that the fine particles are made of two or more kinds of fine particles having different average particle diameters.

  The touch panel of the present invention is characterized by having a hard coat layer containing fine particles on the other surface of the substrate (A).

  The average particle size and the variation coefficient of the particle size distribution referred to in the present invention are calculated from values measured by a Coulter counter method.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in the Newton ring prevention property at the time of pressing a touch panel, the touch panel excellent in durability of an electroconductive film is obtained.

  First, an embodiment of the touch panel of the present invention will be described with reference to FIG. As shown in FIG. 1, the touch panel of the present invention is arranged with a spacer S so that the conductive films Da and Db of a pair of panel plates Pa and Pb having conductive films Da and Db face each other. The panel panel Pa on the side to be pressed is a resistive film type touch panel including at least a base material (A) 1, an adhesive layer 2, a base material (B) 3, and a conductive film Da in this order. The conductive film Da, Db of either or both of the panel plate Pa (hereinafter also referred to as the upper panel plate) and Pb (hereinafter also referred to as the lower panel plate) is an arithmetic average according to JIS B0601: 1994. It is provided on the Newton ring prevention layer 4 having a roughness (Ra) of 0.07 μm to 0.3 μm and a maximum height (Ry) of 1.5 μm to 2.0 μm.

  Hereinafter, embodiments of each component will be described.

  As the base material (A) 1 and the base material (B) 3 used in the upper panel plate Pa, a highly transparent material such as a glass plate or a plastic film can be used. As the plastic film, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polystyrene, triacetyl cellulose, acrylic, polyvinyl chloride, norbornene compound and the like that can be used can be used and stretched Processing, particularly biaxially stretched polyethylene terephthalate film is preferably used because it is excellent in mechanical strength and dimensional stability. Such a base material (A) 1 and a base material (B) 3 should be subjected to plasma treatment, corona discharge treatment, far-ultraviolet irradiation treatment, and easy adhesion treatment such as formation of an undercoat easy adhesion layer. Is preferred.

  The thickness of the base material (A) 1 and the base material (B) 3 is not particularly limited and can be appropriately selected depending on the applied material. In the case of the base material (A) 1, an input pen or the like In view of durability, the thickness is preferably about 25 μm to 500 μm, and more preferably about 50 μm to 300 μm. Moreover, in the case of the base material (B) 3, since it is not pressed directly with an input pen or the like, it is not necessary to consider durability as compared with the base material (A) 1, but in consideration of handleability. The thickness is preferably about 4 μm to 100 μm, more preferably about 10 μm to 75 μm.

  Next, the pressure-sensitive adhesive layer 2 is used to bond the base material (A) 1 and the base material (B) 3 together, and between the base material (A) 1 and the base material (B) 3, By interposing the pressure-sensitive adhesive layer 2, the cushioning effect improves the scratch resistance of the surface to be pressed of the panel plate Pa, and gives the panel plate Pa an appropriate elastic deformation property. The writing quality is very good.

  As the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer 2, generally used synthetic resin-based pressure-sensitive adhesives such as acrylic, silicone, urethane and rubber are used, and acrylic pressure-sensitive adhesive is used in terms of transparency. preferable. As an adhesive polymer which is the main component of such an acrylic adhesive, the alkyl group such as 2-ethylhexyl acrylate, butyl acrylate, isooctyl acrylate, butyl methacrylate and propyl methacrylate has 1 to 1 carbon atoms. A monomer comprising 10 (meth) acrylic acid alkyl esters and a functional group-containing unsaturated monomer such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, etc. as main components A product obtained by copolymerizing a body mixture is preferably used. In the pressure-sensitive adhesive layer 2, in addition to the above-mentioned pressure-sensitive polymer component, various additives such as a crosslinking agent, a plasticizer, and a tackifier component may be included as long as the effects of the present invention are not impaired. it can.

  What is necessary is just to select the thickness according to the material of the base material (A) 1 suitably as the thickness of the adhesive layer 2, and it is usually preferable to set it as about 10 micrometers-about 100 micrometers.

  Such a pressure-sensitive adhesive layer 2 is, for example, a coating liquid for a pressure-sensitive adhesive layer by mixing the above-mentioned pressure-sensitive adhesive, an additive added as necessary, and a dilution solvent on one surface of the substrate (A) 1. And coating and drying by a known coating method such as bar coater, die coater, blade coater, spin coater, roll coater, gravure coater, flow coater, spray, screen printing, etc. 3 is bonded to a surface opposite to the surface on which the Newton ring prevention layer 4 is provided, and is crosslinked by necessity.

  The pressure-sensitive adhesive layer 2 is not limited to such a forming method, and is applied to the surface of the base material (B) 3 opposite to the surface on which the Newton ring prevention layer 4 is provided, and then dried. (A) 1 may be bonded together, and for example, a desired pressure-sensitive adhesive layer 2 previously formed on a separator is bonded to a base material (A) 1 or a base material (B) 3, It can also be obtained by bonding the material (A) 1 and the base material (B) 3 together.

  Next, the Newton ring prevention layer 4 will be described. The Newton ring prevention layer 4 in the present invention has an arithmetic average roughness (Ra) in JIS B0601: 1994 of 0.07 μm to 0.3 μm, preferably 0.15 μm to 0.2 μm, and a maximum height (Ry). It is necessary to be 1.5 μm to 2.0 μm.

  By setting the arithmetic average roughness (Ra) in JIS B0601: 1994 to 0.07 μm or more, Newton's ring prevention can be imparted, and by setting it to 0.3 μm or less, transparency and visibility are lowered. Can be prevented.

  Moreover, Newton ring prevention property can be provided by setting the maximum height (Ry) in JIS B0601: 1994 to 1.5 μm or more while keeping Ra in the above range, and by setting it to 2.0 μm or less, It is possible to prevent the durability of the conductive films Da and Db from being lowered.

  Here, since the touch panel 7 of the present invention having the above-mentioned pressure-sensitive adhesive layer 2 on the upper panel plate Pa has the pressure-sensitive adhesive layer 2 when pressed, the panel plate Pa has an appropriate elastic deformation property. Therefore, as compared with a touch panel that does not have an adhesive layer on the upper panel plate (not shown), deflection occurs downward about the pressed point. Due to this deflection, the area in contact with the conductive films Da and Db of the Newton ring prevention layer 4 when pressed is larger than that of the general touch panel. Accordingly, the touch panel 7 having the structure having the adhesive layer 2 on the upper panel Pa has a larger number of convex portions of the Newton ring prevention layer 4 in contact with the conductive films Da and Db than the general touch panel. Is in the above-mentioned range, if the convex part of the Newton ring prevention layer 4 includes the one having a maximum height (Ry) exceeding 2.0 μm, the conductive film Da, Db generated each time it is pressed is applied. Damage will increase.

  However, by setting the maximum height (Ry) of the convex portion of the Newton ring prevention layer 4 in contact with the conductive films Da and Db to 2.0 μm or less, damage to the conductive films Da and Db that occurs each time it is pressed is prevented. It can be minimized, and the durability of the conductive films Da and Db can be prevented from being lowered.

  That is, in the present invention, the Newton ring prevention layer 4 has an arithmetic average roughness (Ra) of 0.07 μm to 0.3 μm in JIS B0601: 1994 and a maximum height (Ry) of 1.5 μm to 2. By setting the thickness to 0 μm, it is possible to prevent the durability of the conductive films Da and Db from being deteriorated even in the touch panel 7 having the pressure-sensitive adhesive layer 2 on the pressed panel panel Pa.

  Such a Newton ring prevention layer 4 has a binder component 41 and a surface of the base material (B) 3 opposite to the surface having the pressure-sensitive adhesive layer 2 and / or one surface of the base material (C) 6. A coating liquid containing the fine particles 42 formed by a conventionally known coating method (FIGS. 2 to 5), a substrate (B) 3 formed by sandblasting or embossing, Examples of the material (B) include a film formed by blending fine particles in advance. From the viewpoint of transparency, production stability, ease of surface hardness control, and the like, the binder component 41 and the fine particles 42 And those formed by a coating method are preferred.

  When the Newton ring prevention layer 4 is composed of a binder component 41 and fine particles 42 and is formed by a coating method, the binder component 41 is composed of an ionizing radiation curable resin composition and another resin component, The content of the other resin component is preferably 0.1 wt% to 15 wt% in the total solid content in the binder component 41.

  By forming the ionizing radiation curable resin composition by a coating method, the Newton's ring prevention layer 4 to which the fine particles 42 are added generates “undulations” that are wavy uneven shapes on the surface thereof. Even when the size of 42 is small and the addition amount is small, irregularities can be formed on the surface, and the generation of Newton rings can be prevented. Moreover, since the addition amount of the fine particles 42 that cause damage can be made small, it is possible to prevent a decrease in durability.

  As such an ionizing radiation curable resin composition, a photopolymerizable prepolymer that can be cross-linked and cured by irradiation with ionizing radiation (ultraviolet rays or electron beams) can be used. As the photopolymerizable prepolymer, An acrylic prepolymer having two or more acryloyl groups in one molecule and having a three-dimensional network structure by crosslinking and curing is particularly preferably used. As the acrylic prepolymer, urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate and the like can be used. Furthermore, these acrylic prepolymers can be used alone, but it is preferable to add a photopolymerizable monomer in order to improve the cross-linking curability and further improve the hardness of the Newton ring prevention layer 4.

  As photopolymerizable monomers, monofunctional acrylic monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, butoxyethyl acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol One kind of bifunctional acrylic monomer such as diacrylate, polyethylene glycol diacrylate, hydroxypivalate ester neopentyl glycol diacrylate, etc., or polyfunctional acrylic monomer such as dipentaerythritol hexaacrylate, trimethylpropane triacrylate, pentaerythritol triacrylate or the like Two or more are used.

  In addition to the above-described photopolymerizable prepolymer and photopolymerizable monomer, the Newton ring prevention layer 4 preferably uses additives such as a photopolymerization initiator and a photopolymerization accelerator when cured by ultraviolet irradiation.

  Examples of the photopolymerization initiator include acetophenone, benzophenone, Michler's ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, α-acyloxime ester, thioxanthone and the like.

  Further, the photopolymerization accelerator can reduce the polymerization obstacle due to air at the time of curing and increase the curing speed. For example, p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, and the like. can give.

  It is also preferable to use an ionizing radiation curable organic-inorganic hybrid resin as the ionizing radiation curable resin composition. The ionizing radiation curable organic-inorganic hybrid resin referred to in the present invention is different from the old composites represented by glass fiber reinforced plastic (FRP) in that the organic and inorganic materials are mixed closely and in a dispersed state. Is at or close to the molecular level, and by irradiation with ionizing radiation, an inorganic component and an organic component react to form a film. Examples of the inorganic component of the ionizing radiation curable organic-inorganic hybrid resin include metal oxides such as silica and titania. Among them, those using silica are preferable.

  Next, the binder component 41 preferably contains a specific amount of other resin components in addition to the ionizing radiation curable resin composition described above. By containing a specific amount of other resin components, the surface shape is adjusted to make the "undulation" on the surface of the Newton ring prevention layer 4 slightly delicate, and while maintaining the Newton ring prevention property, the conductive film The contact surface area of the convex portion can be increased with respect to Da and Db, and damage to the conductive films Da and Db can be minimized (FIG. 2).

  Here, for example, when the Newton ring prevention layer 4 as described above is produced using only a thermosetting resin or a thermoplastic resin as the binder component 41, as shown in FIG. Since “undulation” does not occur, Newton's ring prevention effect cannot be obtained. Therefore, in order to obtain a shape that prevents the occurrence of Newton rings, the particle diameter of the fine particles 42 must be increased and the amount added must be increased. In such a Newton ring prevention layer 4, it is possible to maintain transparency. The generation of scratches in the conductive films Da and Db cannot be suppressed (FIG. 4).

  Further, for example, when the Newton ring prevention layer 4 as described above is produced using only the ionizing radiation curable resin composition as the binder component 41, “undulation” is formed on the surface of the Newton ring prevention layer 4 as described above. Therefore, even if the addition amount of the fine particles 42 is small, the generation of Newton rings can be prevented (FIG. 5). However, in FIG. 5, the shape of “swell” is not relaxed as in FIG. 2, and the contact surface area of the convex portion with respect to the conductive films Da and Db is smaller than that in FIG. Since the damage to the conductive films Da and Db is increased, the one shown in FIG. 2 containing the ionizing radiation curable resin composition and other resin components does not lower the durability of the conductive films Da and Db. be able to.

  Examples of such other resin components include polyester acrylate resins, polyurethane acrylate resins, epoxy acrylate resins, polyester resins, acrylic resins, polycarbonate resins, epoxy resins, cellulose resins, acetal resins, Thermoplastic resins such as vinyl resins, polyethylene resins, polystyrene resins, polypropylene resins, polyamide resins, polyimide resins, melamine resins, phenol resins, silicone resins, fluorine resins, and composite resins thereof, Thermosetting resins and the like can be mentioned, but it is preferable to use a thermoplastic resin in terms of easy adjustment of the surface shape and excellent handleability, and a glass transition temperature of 50 ° C. to 120 ° C., further 65 ° C. to A resin at 100 ° C. is preferred. By setting the glass transition temperature to 50 ° C. or higher, the shape of the “swell” can be relaxed and the surface shape can be adjusted without containing a large amount, so that the physical properties such as the surface hardness are reduced. Can be prevented. Further, by setting the glass transition temperature to 120 ° C. or lower, it is possible to prevent the “undulation” shape from being relaxed more than necessary, and the surface shape can be easily adjusted. As the glass transition temperature increases, the effect of relaxing the shape of the “swell” increases, so the amount of other resin components added can be reduced. Since the shape of the “swell” is relaxed sensitively, it is difficult to adjust the surface shape.

  The content of such other resin components varies depending on the type of the other resin components selected, the glass transition temperature, etc., but it cannot be generally stated, but 0.1% by weight in the total solid content in the binder component -15% by weight, preferably about 1% to 8% by weight. By making the content of other resin components 0.1% by weight or more, the shape of “swell” can be relaxed, and by making it 15% by weight or less, the shape of “swell” can be relaxed more than necessary. It can prevent that physical properties, such as surface hardness, fall.

  The surface hardness of the Newton ring prevention layer 4 is not particularly limited and cannot be generally specified because it varies depending on the type of the base material (B) 3 to be selected. However, the pencil hardness in JIS K5600-5-4: 1999 is H or more. It is preferable that

  Next, the fine particles 42 used for the Newton ring prevention layer 4 will be described. The fine particles 42 prevent the Newton ring from being generated by forming convex portions of the fine particles on the surface of the Newton ring preventing layer 4 and causing the “undulation” in the Newton ring preventing layer 4 as described above. Add for. The type of the fine particles 42 is not particularly limited, inorganic particles such as calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, silica, kaolin, clay, talc, acrylic resin particles, polystyrene resin particles, polyurethane resin particles, Resin particles such as polyethylene resin particles, benzoguanamine resin particles, epoxy resin particles, and silicone resin particles can be used. Such fine particles 42 include a reduction in damage to the conductive films Da and Db, ease of control of the surface shape such as arithmetic average roughness (Ra) and maximum height (Ry), and ease of handling. In view of the above, it is preferable to use spherical fine particles, and it is preferable to use resin particles from the viewpoint of not inhibiting transparency.

  The size of the fine particles 42 is not particularly limited, but preferably the average particle diameter is 0.5 μm to 3.0 μm, more preferably 1.0 μm to 2.5 μm. By setting the average particle diameter of the fine particles 42 in such a range, it is possible to obtain the Newton ring prevention layer 4 that has excellent Newton ring prevention properties and excellent durability of the conductive films Da and Db.

  When the average particle size of the fine particles 42 is in the above range, the variation coefficient of the particle size distribution of the fine particles 42 is preferably 20% to 80%, more preferably 30% to 70%, More preferably, it is 40% to 60%. By making the variation coefficient of the particle size distribution of the fine particles 42 20% or more, it is possible to prevent the visibility from being lowered. By making the variation coefficient of the particle size distribution of the fine particles 42 80% or less, it is transparent. In addition, the fine particles that damage the conductive films Da and Db can be eliminated, and thus the generation of scratches on the conductive films Da and Db can be suppressed. In addition, the variation coefficient of the particle size distribution of the fine particles 42 when the average particle size of the fine particles 42 is larger than 3.0 μm varies depending on the average particle size of the fine particles 42 to be used. From the viewpoint of suppressing the occurrence of scratches on the conductive films Da and Db, it is preferable to use a film having a sharper shape than the above range.

  The variation coefficient of the particle size distribution of the fine particles 42 is a value indicating a variation state of the particle size distribution of the fine particles 42, and is a percentage of a value obtained by dividing the standard deviation of the particle size distribution by the average particle size {variation Coefficient = (square root of unbiased variance) / (arithmetic mean value) × 100%}.

  It is also preferable to use two or more kinds of fine particles 42 having different average particle diameters. When two or more types of fine particles are used, the variation coefficient of the particle size distribution of the fine particles may be less than 20%. By using two or more kinds of fine particles having different average particle diameters in this way, control of the surface shape such as arithmetic average roughness (Ra) and maximum height (Ry) becomes easy, and transparency and visibility are improved. It is possible to prevent the decrease.

  The thickness of the Newton ring prevention layer 4 is 20% to the average particle diameter when the size of the fine particles 42 is in the above range (average particle diameter is 0.5 μm to 3.0 μm). The thickness is preferably 80%, preferably 40% to 80%. By setting the average particle diameter to 20% or more, the fine particles 42 can be prevented from falling off the Newton ring prevention layer 4. Moreover, the convex part by the microparticles | fine-particles 42 can be formed in the Newton ring prevention layer 4 surface by setting it as 80% or less with respect to an average particle diameter. In particular, when the size of the fine particles 42 is in the above range, even if the thickness of the Newton ring prevention layer 4 is in the above range (20% or more as the lower limit), the scratches on the conductive films Da and Db Can be suppressed. On the other hand, the thickness of the Newton ring prevention layer 4 when the average particle diameter of the fine particles 42 is larger than 3.0 μm varies depending on the average particle diameter of the fine particles 42 used, but the scratches on the conductive films Da and Db. From the viewpoint of suppressing the occurrence of the above, it is preferable to set a value larger than the above lower limit value.

  In addition, the thickness of the Newton ring prevention layer 4 means the thickness of the resin part in which the convex part is not formed with the microparticles | fine-particles 42. FIG.

  Further, the amount of the fine particles 42 added is not particularly limited, but is preferably about 0.5 wt% to 1.5 wt% in the total solid content constituting the Newton ring prevention layer 4. By making the addition amount of the fine particles 42 0.5% by weight or more, good Newton ring prevention properties can be imparted. The reason why it is set to 1.5% by weight or less is that, even if it is added more than that, the Newton's ring preventing property does not change, and only the deterioration of transparency and the occurrence of scratches on the conductive films Da and Db are caused. The upper panel plate Pa in the present invention preferably has a haze of less than 3.0% in JIS K7136: 2000.

  In addition to the binder component and fine particles, Newton's ring prevention layer 4 is a lubricant, fluorescent whitening agent, pigment, antistatic agent, flame retardant, antibacterial agent, and mold prevention agent as long as the effects of the present invention are not impaired. Various additives such as an agent, an ultraviolet absorber, a light stabilizer, an antioxidant, a plasticizer, a leveling agent, a flow regulator, an antifoaming agent, a dispersant, a mold release agent, and a crosslinking agent can be included.

  Such a Newton ring prevention layer 4 is formed on the surface of the substrate (B) 3 opposite to the surface having the pressure-sensitive adhesive layer 2 and / or one surface of the substrate (C) 6 described above. 41 (ionizing radiation curable resin composition, other resin components), fine particles 42, and additives and diluents added as necessary were mixed to prepare a coating solution for Newton's ring prevention layer 4, and the conventional method described above It can be obtained by applying, drying, and curing by irradiating with ionizing radiation by a known coating method.

  As a method of irradiating with ionizing radiation, ultraviolet rays in a wavelength region of 100 nm to 400 nm, preferably 200 nm to 400 nm, emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, etc. are irradiated or scanned. The irradiation can be performed by irradiating an electron beam having a wavelength region of 100 nm or less emitted from a type or curtain type electron beam accelerator.

  The Newton's ring prevention layer 4 in the present invention as described above is excellent in Newton's ring prevention property by using the ionizing radiation curable resin composition and the other resin components in a specific ratio as described above, and is conductive. It can be set as the touch panel 7 excellent in durability of the conductive films Da and Db. Moreover, since the addition amount of the fine particles 42 is small, it is possible to prevent the transparency and visibility from being lowered.

  Next, the touch panel 7 of the present invention preferably has a hard coat layer 5 containing fine particles on the surface of the substrate (A) 1 that does not have the pressure-sensitive adhesive layer 2. By having such a hard coat layer 5, when the touch panel 7 is formed, the surface is prevented from being damaged by nails and the like, and the reflection of light such as a fluorescent lamp is reflected by the synergistic effect with the Newton ring prevention layer 4 described above. Can be effectively prevented.

  As the fine particles, the same fine particles as those used in the Newton ring prevention layer 4 described above can be used alone or in combination of two or more. Further, the size of the fine particles and the coefficient of variation of the particle size distribution are not particularly limited, but are preferably in the same range as described above in consideration of transparency and image visibility. The content of the fine particles varies depending on the kind of the binder component for containing the fine particles described later and the thickness of the hard coat layer, and is not particularly limited, but is 2 parts by weight with respect to 100 parts by weight of the solid content of the binder component. -20 parts by weight, further 4 parts by weight to 18 parts by weight, more preferably 6 parts by weight to 16 parts by weight. By setting it as such a range, when it is set as an upper panel board, haze in JIS K7136: 2000 can be 20% or less, Furthermore, it can be 10% or less, and it is a reflection preventing property, maintaining transparency. The effect can be demonstrated.

  Next, as a binder component for containing fine particles, it is preferable to mainly use a thermosetting resin or an ionizing radiation curable resin composition. In particular, transparency can be achieved by generating the above-described “swell”. In view of the point that the reflection preventing property can be imparted while maintaining the above and the point that the excellent scratch prevention property can be imparted, it is preferable to use the ionizing radiation curable resin composition. As the ionizing radiation curable resin composition, the same ones as described above can be used.

  The hard coat layer 5 as described above can contain various additives similar to the Newton ring prevention layer 4 described above as long as the function of the present invention is not impaired.

  Such a hard coat layer 5 is formed on the surface opposite to the surface on which the pressure-sensitive adhesive layer 2 of the base material (A) 1 is provided, and the binder component, fine particles, and additives and dilutions added as necessary. By mixing a solvent to prepare a coating solution for the hard coat layer 5, applying and drying by the above-mentioned conventionally known coating method, and curing with heat or irradiating with ionizing radiation as described above if necessary It can be cured to form. The Newton ring prevention layer 4 and the hard coat layer 5 may be formed first.

  Next, the touch panel 7 of the present invention is a resistance film formed by placing a spacer S so that the conductive films Da and Db of the pair of panel plates Pa and Pb having the conductive films Da and Db face each other. It is a touch panel 7 of the type, and one or both of the conductive films Da and Db are formed on the Newton ring prevention layer 4 described above.

  The conductive films Da and Db include metals such as In, Sn, Au, Al, Cu, Pt, Pd, Ag, and Rh, and metal oxides such as indium oxide, tin oxide, and composite oxides such as ITO. Transparent and conductive inorganic thin films made from organic materials, and organic materials made from aromatic conductive polymers such as polyparaphenylene, polyacetylene, polyaniline, polythiophene, polyparaphenylene vinylene, polypyrrole, polyfuran, polyselenophene, and polypyridine The thin film is mentioned. The inorganic thin film is obtained by a vacuum film forming method such as a vacuum deposition method, a sputtering method, or an ion plating method, and the organic thin film is obtained by a conventionally known coating method similar to the Newton ring prevention layer.

  The spacer S secures a gap between the panel plates when the pair of panel plates Pa and Pb is used, controls the load at the time of touching, and improves the separation from the panel plates Pa and Pb after touching. Formed to do. Such a spacer S is generally made of a transparent ionizing radiation curable resin and can be obtained by forming into fine dots by a photo process. Moreover, it can also form by printing many fine dots by printing methods, such as a silk screen, using urethane type resin. It can also be obtained by spraying or applying a dispersion of particles made of inorganic or organic matter and drying. Since the size of the spacer S varies depending on the size of the touch panel 7, it cannot be generally specified, but is generally formed in a dot shape having a diameter of 30 μm to 100 μm and a height of 1 μm to 15 μm, and arranged at regular intervals of 0.1 mm to 10 mm. Is done.

  As the lower panel plate Pb, a base material (C) 6 made of the same material as the base material (A) 1 and base material (B) 3 described above, or a Newton ring prevention layer similar to that described above on the base material (C) 6 is used. 4 can be used, and can be obtained by providing the above-described conductive film Db on one surface of the substrate (C) 6 or on the Newton ring prevention layer 4.

  As described above, according to the present invention, the conductive films Da and Db of the pair of panel plates Pa and Pb having the conductive films Da and Db are arranged via the spacer S so as to face each other. The panel panel Pa to be pressed is a resistive film type touch panel 7 including at least a base material (A) 1, an adhesive layer 2, a base material (B) 3, and conductive films Da and Db in this order, The conductive film Da, Db of either or both of the pair of panel plates Pa, Pb has an arithmetic average roughness (Ra) of 0.07 μm to 0.3 μm and a maximum height (Ry) in JIS B0601: 1994. Since it is provided on the Newton ring prevention layer 4 having a thickness of 1.5 μm to 2.0 μm, it has excellent Newton ring prevention properties when the touch panel 7 is pressed and also has excellent durability of the conductive films Da and Db. H panel 7.

  Hereinafter, the present invention will be described in more detail based on examples. In this example, “parts” and “%” are based on weight unless otherwise specified.

(1) Production of panel plate of upper electrode [Example 1]
On one side of a 50 μm thick polyester film (Cosmo Shine A4300: Toyobo Co., Ltd.) as the base material (B), the Newton's ring-preventing layer coating solution of the following formulation is applied and dried, and then irradiated with ultraviolet light with a high-pressure mercury lamp. A Newton ring prevention layer having a thickness of 1.5 μm was formed.

  Next, an ITO conductive film having a thickness of about 20 nm is formed on the Newton ring prevention layer by a sputtering method, and a coating solution for the pressure-sensitive adhesive layer having the following formulation is applied to the other surface and dried to a thickness of 20 μm. The pressure-sensitive adhesive layer was formed.

  Next, a hard coat layer coating solution having the following formulation is applied to one surface of a 188 μm thick polyester film (Cosmo Shine A4300: Toyobo Co., Ltd.) as the base material (A), dried, and then irradiated with ultraviolet light with a high-pressure mercury lamp. Then, a hard coat layer having a thickness of about 5 μm is formed, and the other surface of the substrate (A) and the surface having the pressure-sensitive adhesive layer of the substrate (B) are bonded to each other. The panel was cut into a rectangle of 87.3 mm and a width of 64.0 mm, and the panel plate of the upper electrode of Example 1 was produced.

<Formulation of coating liquid for Newton ring prevention layer of Example 1>
-46.5 parts of ionizing radiation curable resin composition (100% solid content)
(Beamset 575: Arakawa Chemical Industries)
Other resin component a (solid content 100%) 3.5 parts Fine particles (acrylic resin particles) 0.3 parts (average particle diameter 2 μm) (coefficient of variation 20%)
・ Fine particles (acrylic resin particles) 0.1 parts (average particle diameter 3 μm) (coefficient of variation 20%)
・ Isopropyl alcohol 200 parts ・ Photopolymerization initiator 1.4 parts (Irgacure 651: Ciba Specialty Chemicals)

  A thermoplastic resin (Byron 296: Toyobo Co., Ltd.) having a glass transition temperature of 71 ° C. was used as the other resin component a, and was added so as to be 7% of the total solid content in the binder component.

<Prescription of coating liquid for pressure-sensitive adhesive layer of Example 1>
-Thermosetting pressure sensitive adhesive (solid content 25%) 100 parts (SK Dyne 2094: Soken Chemical Co., Ltd.)
Curing agent (solid content: 100%) 0.27 part (E-AX: Soken Chemical Co., Ltd.)

<Prescription of coating liquid for hard coat layer of Example 1>
・ Ionizing radiation curable resin composition (solid content: 100%) 30 parts (Diabeam UR6530: Mitsubishi Rayon)
・ Fine particles (silica) 1.5 parts (average particle diameter 4.5 μm) (coefficient of variation 60%)
・ Fine particles (silica) (average primary particle size 30 nm) 1.5 parts (Aerosil 50: Nippon Aerosil Co., Ltd.)
・ 0.90 parts of photopolymerization initiator (Irgacure 651: Ciba Specialty Chemicals)
・ Methyl ethyl ketone 40 parts ・ Toluene 30 parts

[Example 2]
In the coating solution for Newton's ring prevention layer of Example 1, 0.3 part of acrylic resin particles having an average particle diameter of 2 μm, 0.1 part of acrylic resin particles having an average particle diameter of 3 μm, an average particle diameter of 2 μm, and a coefficient of variation of 50% The upper electrode panel plate of Example 2 was prepared in the same manner as in Example 1 except that the acrylic resin particles were changed to 0.4 part of the above and a 1.5 μm-thick Newton ring prevention layer was formed.

[Example 3]
A panel plate for the upper electrode of Example 3 was prepared in the same manner as in Example 2 except that the coating solution for Newton's ring prevention layer of Example 2 was changed to the coating solution for Newton's ring prevention layer having the following formulation. In addition, the thermoplastic resin (Byron 240: Toyobo Co., Ltd.) whose glass transition temperature is 60 degreeC was used as the other resin component b, and it added so that it might become 10% in the total solid in a binder component.

<Prescription of coating solution for Newton ring prevention layer of Example 3>
・ Ionizing radiation curable resin composition (solid content: 100%) 45 parts (Beamset 575: Arakawa Chemical Industries)
Other resin component b (solid content 100%) 5 parts Fine particles (acrylic resin particles) 0.4 parts (average particle diameter 2 μm) (coefficient of variation 50%)
・ Isopropyl alcohol 200 parts ・ Photopolymerization initiator 1.4 parts (Irgacure 651: Ciba Specialty Chemicals)

[Example 4]
A panel plate for the upper electrode of Example 4 was produced in the same manner as in Example 2 except that the coating liquid for Newton's ring prevention layer of Example 2 was changed to the coating liquid for Newton's ring prevention layer having the following formulation. As another resin component c, a thermoplastic resin having a glass transition temperature of 105 ° C. (Thermolac LP45M: Soken Chemical Co., Ltd.) was used and added so as to be 3% of the total solid content in the binder component.

<Prescription of coating solution for Newton ring prevention layer of Example 4>
-Ionizing radiation curable resin composition 48.5 parts (solid content 100%)
(Beamset 575: Arakawa Chemical Industries)
Other resin component c (solid content 40%) 3.8 parts Fine particles (acrylic resin particles) 0.4 parts (average particle diameter 2 μm) (coefficient of variation 50%)
・ Methyl ethyl ketone 200 parts ・ Photopolymerization initiator 1.5 parts (Irgacure 651: Ciba Specialty Chemicals)

[Example 5]
The coating solution for Newton's ring prevention layer of Example 2 was changed to the coating solution for Newton's ring prevention layer having the following formulation, and after forming a Newton's ring prevention layer in the same manner as Example 2, curing at 60 ° C. for 48 hours Thus, a panel plate for the upper electrode of Example 5 was produced. As another resin component d, a thermosetting resin having a glass transition temperature of 70 ° C. (Acridic A808: Dainippon Ink & Chemicals, Inc.) was used and added so as to be 7% of the total solid content in the binder component. .

<Prescription of coating liquid for Newton ring prevention layer of Example 5>
-46.5 parts of ionizing radiation curable resin composition (100% solid content)
(Beamset 575: Arakawa Chemical Industries)
・ Other resin component d (solid content 50%) 7 parts ・ Crosslinking agent (polyisocyanate) (solid content 60%) 1 part (Takenate D110N: Mitsui Takeda Chemical Company)
・ Fine particles (acrylic resin particles) 0.4 parts (average particle diameter 2 μm) (coefficient of variation 50%)
・ Methyl ethyl ketone 200 parts ・ Photopolymerization initiator 1.4 parts (Irgacure 651: Ciba Specialty Chemicals)

[Example 6]
The top electrode of Example 6 was changed in the same manner as in Example 2 except that the fine particles of the coating liquid for Newton's ring prevention layer of Example 2 were changed to acrylic resin particles having an average particle diameter of 2 μm and a coefficient of variation of 33%. A panel board was produced.

[Comparative Example 1]
A panel plate for the upper electrode of Comparative Example 1 was produced in the same manner as in Example 2 except that the coating solution for Newton's ring prevention layer of Example 2 was changed to the coating solution for Newton's ring prevention layer having the following formulation.

<Prescription of Coating Solution for Newton Ring Prevention Layer of Comparative Example 1>
・ Ionizing radiation curable resin composition (solid content: 100%) 50 parts (Beamset 575: Arakawa Chemical Industries)
・ Fine particles (acrylic resin particles) 0.4 parts (average particle diameter 2 μm) (coefficient of variation 50%)
・ 200 parts isopropyl alcohol

[Comparative Example 2]
Comparative Example 1 except that the fine particles of the coating liquid for Newton's ring prevention layer of Comparative Example 1 were changed to acrylic resin particles having an average particle diameter of 9 μm and a coefficient of variation of 50% to form a Newton ring prevention layer having a thickness of 7 μm. Similarly, the panel plate of the upper electrode of Comparative Example 2 was produced.

[Comparative Example 3]
The coating solution for Newton's ring prevention layer of Example 2 was changed to the coating solution for Newton's ring prevention layer of the following formulation, applied and dried to form a Newton's ring prevention layer, and then cured at 60 ° C. for 48 hours. Was the same as Example 2, and produced the panel board of the upper electrode of Comparative Example 3.

<Prescription of Coating Solution for Newton Ring Prevention Layer of Comparative Example 3>
-Thermosetting resin (acrylic resin) (solid content 50%) 81 parts Acrydic A807: Dainippon Ink and Chemicals)
・ Crosslinking agent (polyisocyanate) (solid content 60%) 16 parts (Takenate D110N: Mitsui Takeda Chemical)
・ Fine particles (acrylic resin particles) 0.4 parts (average particle diameter 2 μm) (coefficient of variation 50%)
・ Methyl ethyl ketone 77 parts ・ Toluene 76 parts

[Comparative Example 4]
Comparative Example 3 except that the fine particles of the coating liquid for Newton's ring prevention layer of Comparative Example 3 were changed to acrylic resin particles having an average particle diameter of 9 μm and a coefficient of variation of 50% to form a Newton ring prevention layer having a thickness of 7 μm. Similarly, the panel plate of the upper electrode of Comparative Example 4 was produced.

[Comparative Example 5]
A panel plate for the upper electrode of Comparative Example 5 was produced in the same manner as Comparative Example 4 except that the amount of fine particles added to the coating solution for Newton's ring prevention layer of Comparative Example 4 was changed to 5 parts.

[Comparative Example 6]
A panel plate for the upper electrode of Comparative Example 6 was produced in the same manner as in Example 2 except that the coating solution for Newton's ring prevention layer of Example 2 was changed to the coating solution for Newton's ring prevention layer having the following formulation. The other resin component a was a thermoplastic resin having a glass transition temperature of 71 ° C. as described above, and was added so as to be 20% of the total solid content in the binder component.

<Prescription of Coating Solution for Newton Ring Prevention Layer of Comparative Example 6>
・ Ionizing radiation curable resin composition (solid content: 100%) 40 parts (Beamset 575: Arakawa Chemical Industries)
Other resin component a (solid content 100%) 10 parts Fine particles (acrylic resin particles) 0.4 parts (average particle diameter 2 μm) (coefficient of variation 50%)
・ 200 parts isopropyl alcohol

[Comparative Example 7]
A panel plate for the upper electrode of Comparative Example 7 was produced in the same manner as in Example 2 except that the coating solution for Newton's ring prevention layer of Example 2 was changed to the coating solution for Newton's ring prevention layer having the following formulation. The other resin component a was a thermoplastic resin having a glass transition temperature of 71 ° C. as described above, and was added so as to be 0.06% of the total solid content in the binder component.

<Prescription of Coating Solution for Newton Ring Prevention Layer of Comparative Example 7>
・ Ionizing radiation curable resin composition (solid content: 100%) 50 parts (Beamset 575: Arakawa Chemical Industries)
・ Other resin component a (solid content: 100%) 0.03 part ・ Fine particle (acrylic resin particle) 0.4 part (average particle diameter: 2 μm) (variation coefficient: 50%)
・ 200 parts isopropyl alcohol

[Comparative Example 8]
Comparative example 6 except that the other resin component a of the coating solution for Newton's ring prevention layer of Comparative Example 6 was changed to a thermoplastic resin (Byron GK140: Toyobo Co., Ltd.) having a glass transition temperature of 20 ° C. as the other resin component e. In the same manner as in Example 6, the upper electrode panel plate of Comparative Example 8 was produced. Therefore, the other resin component e is 20% of the total solid content in the binder component.

[Comparative Example 9]
Other than changing the other resin component a of the coating solution for Newton's ring prevention layer of Comparative Example 7 to a thermoplastic resin having a glass transition temperature of 260 ° C. as another resin component f (Vilomax HR15ET: Toyobo Co., Ltd.) In the same manner as Comparative Example 7, a panel plate for the upper electrode of Comparative Example 9 was produced. Therefore, the other resin component f is 0.06% in the total solid content in the binder component.

[Comparative Example 10]
A comparative example was prepared in the same manner as in Example 1 except that the coating solution for Newton's ring prevention layer of Example 1 was changed to the coating solution for Newton's ring prevention layer having the following formulation to form a Newton ring prevention layer having a thickness of 2 μm. Ten upper electrode panel plates were prepared.

<Prescription of Coating Solution for Newton Ring Prevention Layer of Comparative Example 10>
-46.5 parts of ionizing radiation curable resin composition (100% solid content)
(Beamset 575: Arakawa Chemical Industries)
-Other resin component a (solid content 100%) 3.5 parts-Fine particles (acrylic resin particles) 0.1 parts (average particle diameter 2 μm) (variation coefficient 20%)
・ Fine particles (acrylic resin particles) 0.2 parts (average particle diameter 3 μm) (coefficient of variation 20%)
・ Fine particles (acrylic resin particles) 0.1 parts (average particle diameter 4 μm) (coefficient of variation 20%)
・ Isopropyl alcohol 200 parts ・ Photopolymerization initiator 1.4 parts (Irgacure 651: Ciba Specialty Chemicals)

[Comparative Example 11]
The coating liquid for Newton's ring prevention layer of Example 1 was changed to the coating liquid for Newton's ring prevention layer having the following formulation, and a Newton's ring prevention layer having a thickness of 2.5 μm was formed. A panel plate for the upper electrode of Comparative Example 11 was produced.

<Prescription of Coating Solution for Newton Ring Prevention Layer of Comparative Example 11>
-46.5 parts of ionizing radiation curable resin composition (100% solid content)
(Beamset 575: Arakawa Chemical Industries)
-Other resin component a (solid content 100%) 3.5 parts-Fine particles (acrylic resin particles) 0.1 parts (average particle diameter 3 μm) (variation coefficient 20%)
・ Fine particles (acrylic resin particles) 0.2 parts (average particle diameter 4 μm) (coefficient of variation 20%)
・ Fine particles (acrylic resin particles) 0.1 part (average particle size 5 μm) (coefficient of variation 20%)
・ Isopropyl alcohol 200 parts ・ Photopolymerization initiator 1.4 parts (Irgacure 651: Ciba Specialty Chemicals)

[Comparative Example 12]
The fine particles of the coating liquid for Newton's ring prevention layer of Example 2 were changed to acrylic resin particles having an average particle diameter of 5 μm and a coefficient of variation of 50%, and a Newton's ring prevention layer having a thickness of 4 μm was formed. Similarly, the panel plate of the upper electrode of Comparative Example 12 was produced.

(2) Production of panel plate of lower electrode As a base material (C), a conductive film of ITO having a thickness of about 20 nm is formed on one surface of a tempered glass plate having a thickness of 1 mm by sputtering. A panel plate of a lower electrode was produced by cutting into a rectangle (length: 87.3 mm, width: 64.0 mm).

(3) Production of spacer On the surface of the lower electrode panel plate having the conductive film, an ionizing radiation curable resin (Dot Cure TR5903: Taiyo Ink Co., Ltd.) was printed in the form of dots by a screen printing method as a spacer coating solution. Thereafter, ultraviolet rays were irradiated with a high-pressure mercury lamp, and spacers having a diameter of 50 μm and a height of 8 μm were arranged at intervals of 1 mm.

(4) Production of Touch Panel The panel plates of the upper electrodes and the panel plates of the lower electrodes of Examples 1 to 6 and Comparative Examples 1 to 12 are arranged so that the conductive films of the panel plates face each other, The edges were bonded with a double-sided adhesive tape having a thickness of 30 μm and a width of 3 mm so that the bonded portion was outside the display surface area, and touch panels of Examples and Comparative Examples were produced.

(5) Evaluation The arithmetic average roughness (Ra) and maximum height (Ry) in JIS B0601: 1994 were measured about the Newton ring prevention layer of the touch panel obtained in Examples 1-6 and Comparative Examples 1-12. . Moreover, about the touch panel obtained in Examples 1-6 and Comparative Examples 1-12, the Newton ring prevention property and durability of the electroconductive film were evaluated. The results are shown in Table 1.

-Newton ring prevention property About the touch panel obtained in Examples 1-6 and Comparative Examples 1-12, it pressed with the finger | toe from the panel board side of the upper electrode, and evaluated visually whether Newton ring generate | occur | produced. In the evaluation, “○” indicates that no Newton ring was generated, and “×” indicates that a Newton ring was generated.

-Durability of a conductive film About the touch panel obtained in Examples 1-6 and Comparative Examples 1-12, the pen slidability test was done. The touch panel was placed on the printing table of the pen plotter so that the hard coat layer of the panel plate of the upper electrode was facing upward, and evaluation was performed by reciprocating a polyacetal resin pen having a diameter of 1.6 mm with a load of 500 g. . The evaluation was “◯” when the linearity change rate was 1% or less after 300,000 reciprocations, and “X” when the linearity change rate exceeded 1% after 300,000 reciprocations.

  As is clear from the results in Table 1, Examples 1 to 6 are arranged on a side to be pressed by arranging a spacer so that the conductive films of the pair of panel plates having the conductive film face each other. The panel plate is a resistive film type touch panel in which at least a base material (A), an adhesive layer, a base material (B), and a conductive film are provided in order, and the conductive film of the panel plate on the side to be pressed is , Because the arithmetic average roughness (Ra) according to JIS B0601: 1994 is 0.07 μm to 0.3 μm and the maximum height (Ry) is 1.5 μm to 2.0 μm. It became the touch panel which was excellent in the Newton ring prevention property at the time of pressing a touch panel, and was excellent in the durability of an electroconductive film.

  On the other hand, in Comparative Examples 1, 7, 8, 10, 11, and 12, the conductive film of the pressed panel panel had an arithmetic average roughness (Ra) of 0.07 μm to 0.3 μm. Since the thickness (Ry) is provided on the Newton ring prevention layer having a thickness greater than 2.0 μm, the touch panel is excellent in the Newton ring prevention property when the touch panel is pressed. became.

  Next, in Comparative Examples 2 and 5, the conductive film of the panel panel on the pressing side has an arithmetic average roughness (Ra) larger than 0.3 μm and a maximum height (Ry) greater than 2.0 μm to prevent Newton rings. Since it was provided on the layer, it was excellent in the Newton ring prevention property when the touch panel was pressed, but it became a touch panel with low durability of the conductive film.

  In Comparative Example 3, the conductive film of the panel plate to be pressed is provided on the Newton ring prevention layer having an arithmetic average roughness (Ra) smaller than 0.07 μm and a maximum height (Ry) smaller than 1.5 μm. Therefore, although the durability of the conductive film is excellent, the effect of preventing Newton's ring when the touch panel is pressed cannot be obtained.

  In Comparative Example 4, the conductive film of the panel panel on the pressing side had an arithmetic average roughness (Ra) of 0.07 μm to 0.3 μm, but a Newton ring with a maximum height (Ry) smaller than 1.5 μm. Since it is provided on the prevention layer, the conductive film is excellent in durability, but the Newton ring prevention effect when the touch panel is pressed cannot be obtained.

  In Comparative Examples 6 and 9, the conductive film of the panel plate on the pressing side has an arithmetic average roughness (Ra) smaller than 0.07 μm and a maximum height (Ry) of 1.5 μm to 2.0 μm. Since it is provided on the prevention layer, the conductive film is excellent in durability, but the Newton ring prevention effect when the touch panel is pressed cannot be obtained.

  Moreover, since the Newton ring prevention layer of Examples 1-6 uses the ionizing radiation curable resin composition as a binder component, "undulation" generate | occur | produces on the Newton ring prevention layer surface, and even if the addition amount of microparticles is made small. Unevenness could be formed on the surface, and the Newton ring prevention property was excellent. In addition, since the amount of fine particles that cause damage to the conductive film is reduced in this way, the durability of the conductive film is improved. In addition, as a resin component other than the binder component, by containing a specific amount of a resin having a glass transition temperature of 50 ° C. to 120 ° C., the surface shape is adjusted so that the “undulation” shape on the surface of the Newton ring prevention layer is obtained. Durability of the conductive film has been made slightly delicate, maintaining the Newton's ring prevention property, and increasing the contact surface area of the protrusions to the conductive film to minimize damage to the conductive film. It became an excellent one. Moreover, since a resin having a glass transition temperature of 50 ° C. to 120 ° C. was used as another resin component, it was excellent in handleability when used as a Newton ring prevention layer coating solution, and the surface shape was easy to adjust.

  In addition, since the Newton ring prevention layer of Comparative Examples 1 and 2 uses an ionizing radiation curable resin composition as a binder component, “undulation” occurs on the surface of the Newton ring prevention layer, and the addition amount of fine particles is small. Unevenness could be formed on the surface, and the Newton ring prevention property was excellent. However, since no other resin component is contained as a binder component, the “undulation” shape of the surface of the Newton ring prevention layer cannot be made slightly gentle, and the contact surface area of the convex portion with respect to the conductive film can be reduced. Since it could not be increased and damage to the conductive film could not be minimized, the conductive film was less durable than Examples 1-6. In particular, Comparative Example 2 contains fine particles that cause damage to the conductive film in the Newton ring prevention layer by using fine particles having an average particle size of more than 3.0 μm and a coefficient of variation of 50%. Therefore, the durability of the conductive film was lower than that of Comparative Example 1.

  In addition, since the Newton ring prevention layer of Comparative Example 3 uses a thermosetting resin as a binder component, “undulation” does not occur on the surface of the Newton ring prevention layer, and the size of the fine particles is small and the addition amount is also small. The ring prevention effect could not be obtained. In addition, the Newton ring prevention layer of Comparative Example 3 had fine particles that looked like foreign matters and looked bad.

  In addition, the Newton ring prevention layer of Comparative Example 4 uses a thermosetting resin as a binder component as in Comparative Example 3, so that “undulation” does not occur on the surface of the Newton ring prevention layer, and the size of the fine particles is large. However, since the addition amount was small, the effect of preventing Newton's ring could not be obtained.

  In addition, since the Newton ring prevention layer of Comparative Example 5 used a thermosetting resin as a binder component as in Comparative Example 4, no “swell” was generated on the surface of the Newton ring prevention layer. It was large and the amount added was great, so it was excellent in Newton ring prevention. However, the increased amount of fine particles increases the number of convex portions of the Newton ring prevention layer in contact with the conductive film, so that the conductive film has low durability compared to Examples 1 to 6. became. Moreover, it became a thing with low transparency.

  Moreover, although the Newton ring prevention layer of the comparative example 6 used the ionizing-radiation-curable resin composition and other resin components as a binder component, content of resin whose glass transition temperature is 50 to 120 degreeC as another resin component Therefore, the shape of the “swell” on the surface of the Newton ring prevention layer is excessively relaxed, and the Newton ring prevention effect cannot be obtained.

  Moreover, although the Newton ring prevention layer of the comparative example 7 used the ionizing-radiation-hardening-type resin composition and other resin components as a binder component, it contains resin whose glass transition temperature is 50 to 120 degreeC as another resin component. Since the amount was less than 0.1% by weight, the shape of the “swell” on the surface of the Newton ring prevention layer could not be relaxed, and the durability of the conductive film was lower than in Examples 1-6.

  Moreover, although the Newton ring prevention layer of the comparative example 8 used the ionizing-radiation-curable resin composition and other resin component as a binder component, the other resin component is a thermoplastic resin whose glass transition temperature is lower than 50 degreeC. Therefore, although the content was increased from 15% by weight, the shape of the “swell” on the surface of the Newton ring prevention layer could not be relaxed, and the conductive film had lower durability than Examples 1-6. It became.

  In addition, the Newton ring prevention layer of Comparative Example 9 used an ionizing radiation curable resin composition as the binder component, and other resin components, but contained as the other resin component because the glass transition temperature exceeds 120 ° C. Although the amount was less than 0.1% by weight, the “undulation” shape on the surface of the Newton ring prevention layer was too relaxed, and the Newton ring prevention effect could not be obtained.

  Moreover, since the Newton ring prevention layer of Comparative Examples 10 and 11 uses an ionizing radiation curable resin composition as a binder component, “undulation” can be generated on the surface of the Newton ring prevention layer, and the Newton ring prevention property is excellent. It became a thing. In addition, as the other resin component of the binder component, a specific amount of resin having a glass transition temperature of 50 ° C. to 120 ° C., the shape of the “undulation” on the surface of the Newton ring prevention layer can be made slightly gentle. Although the contact surface area of the convex portion was increased with respect to the conductive film and the damage to the conductive film was minimized, two or more kinds of fine particles were used, and fine particles having an average particle diameter larger than 3.0 μm And the thickness of the Newton ring prevention layer was too thin with respect to the average particle size of the fine particles, so that it was not possible to suppress the occurrence of scratches on the conductive film. In comparison, the durability of the conductive film was low.

  In addition, since the Newton ring prevention layer of Comparative Example 12 uses an ionizing radiation curable resin composition as a binder component, “undulation” can be generated on the surface of the Newton ring prevention layer, and the Newton ring prevention property is excellent. It became. In addition, as the other resin component of the binder component, because the glass transition temperature is a specific amount of resin of 50 ° C. to 120 ° C., the shape of the “undulation” on the surface of the Newton ring prevention layer can be made slightly gentle, Although it was possible to minimize the damage to the conductive film by increasing the contact surface area of the convex portion with respect to the conductive film, fine particles having an average particle diameter larger than 3.0 μm and a coefficient of variation of 50% were used. As a result, since the Newton ring prevention layer contained fine particles that cause damage to the conductive film, the conductive film was less durable than Examples 1-6.

  Moreover, since the touch panels of Examples 1 to 6 and Comparative Examples 1 to 12 have a hard coat layer containing fine particles on the surface of the panel panel to be pressed, they have a high light reflection preventing property. Especially, since Examples 1 to 6 are specific Newton ring prevention layers, the anti-reflection effect is superior to Comparative Examples 2, 5, and 12 which are conventional Newton ring prevention layers due to their synergistic effects. It became a thing.

Sectional drawing which shows one Example of the touchscreen of this invention Sectional drawing which shows one Example of the Newton ring prevention layer used by this invention Sectional drawing which shows one Example of another Newton ring prevention layer Sectional drawing which shows the other Example of another Newton ring prevention layer Sectional drawing which shows the other Example of another Newton ring prevention layer

Explanation of symbols

1. Base material (A)
2 ... Adhesive layer 3 ... Base material (B)
4 ... Newton ring prevention layer 41 ... Binder component 42 ... Fine particle 5 ... Hard coat layer 6 ... Base material (C)
7. Touch panel Pa ... Panel panel for upper electrode Pb ... Panel panel for lower electrode Da, Db, conductive film S ... Spacer

Claims (8)

  A pair of panel plates having a conductive film are arranged via a spacer so that the conductive films face each other, and the panel plate on the side to be pressed is at least a substrate (A), an adhesive layer, a substrate ( B), and a resistive film type touch panel sequentially provided with a conductive film, wherein one or both of the pair of panel plates has an arithmetic average roughness (Ra) in JIS B0601: 1994. A touch panel characterized by being provided on a Newton ring prevention layer having a height of 0.07 μm to 0.3 μm and a maximum height (Ry) of 1.5 μm to 2.0 μm.   2. The touch panel according to claim 1, wherein the Newton ring prevention layer comprises a binder component and fine particles and is formed by a coating method.   The binder component comprises an ionizing radiation curable resin composition and another resin component, and the content of the other resin component is 0.1 wt% to 15 wt% in the total solid content of the binder component. The touch panel according to claim 2, wherein the touch panel is provided.   The glass transition temperature of said other resin component is 50 to 120 degreeC, The touch panel of Claim 3 characterized by the above-mentioned.   5. The touch panel according to claim 2, wherein an average particle diameter of the fine particles is 0.5 μm to 3.0 μm.   6. The touch panel according to claim 5, wherein a variation coefficient of a particle size distribution of the fine particles is 20% to 80%.   The touch panel according to claim 2, wherein the fine particles are made of two or more types of fine particles having different average particle diameters.   The touch panel according to claim 1, further comprising a hard coat layer containing fine particles on the other surface of the base material (A).

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