JP2011039688A - Optical member for touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical member for a touch panel which is recognizable by a simple input means even under a weak external light environment, and sufficiently reduces malfunction due to the delay of the return (after-image) of deformation after an optical member is depressed. <P>SOLUTION: The optical member for the touch panel is provided with: a first layer and a second layer, arranged oppositely to each other; and a spacer formed between the first layer and the second layer, wherein at least either the first layer or the second layer is formed of an elastic body containing a filler. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical member for a touch panel.

  In recent years, touch panels have been widely used as input devices as display devices become more multifunctional. The touch panel is an input device that can sense a position touched with a finger or a pen. In many cases, it is used in combination with a predetermined device (image display panel) for displaying an image, and also has a function as a display device. Examples of the use of the touch panel include mobile devices such as a mobile phone and a personal digital assistant (PDA), and an automatic teller machine at a bank.

  As a method for detecting the position on the touch panel, for example, a resistance film method, a capacitance method, and an optical sensor method are known.

  In general, a resistive film type touch panel has a transparent conductive film formed on the surface of a glass substrate disposed on the surface of the image display panel on which an image is displayed, a minute spacer is disposed thereon, and a transparent film is further formed thereon. It has a structure in which a conductive film is arranged. In this touch panel, the transparent conductive films facing each other are separated by a spacer, but when the transparent conductive film on the surface side is pressed by touching a finger or the like, this is bent and comes into contact with the other transparent conductive film, As a result, conduction occurs between the transparent conductive films facing each other. And the position which the finger | toe etc. touched is detected based on the resistance change in this conduction | electrical_connection part (refer patent document 1, 2).

  Such a resistive film method has the features that input can be performed with a finger or a pen, an input means is not selected, and the production cost can be reduced because the structure is simple. On the other hand, since the transparent conductive film tends to be brittle, deterioration such as peeling tends to occur due to repeated bending. Therefore, the durability is often low, such as inconveniences such as detection sensitivity, loss of resolution, and decrease in transmittance. Also, resistive film type touch panels generally tend to have low transmittance.

  A capacitive touch panel has a structure including a single layer of transparent conductive film that detects capacitance. The touched position can be detected by sensing a change in the capacitively coupled electrical signal of the part touched with a finger or the like (see Patent Document 1). Such a capacitance method is excellent in durability as compared with the resistance film method, and high transmittance is easily obtained. However, the input means is limited to a finger or a special pen having conductivity, for example, a finger wearing a glove or a normal pen that is not conductive cannot be used for input.

  In the optical sensor system, an optical sensor having a function of sensing light is mounted. For example, when a liquid crystal display (LCD) is used as the image display panel, the optical sensor is disposed in the liquid crystal cell. In such a photosensor touch panel, when a finger is placed on the image display surface, external light incident on the photosensor is blocked by the finger, and the amount of light received by the photosensor changes. And the position which put the finger | toe is detected by the change of this received light quantity (refer patent document 3).

  In this optical sensor system, superior durability can be obtained compared to the resistive film system. In addition, since an optical sensor can be arranged in each pixel of the image display panel, it can be used as an image sensor. For example, there is an advantage that a function of an image scanner can be provided. Furthermore, since multipoint input, which was difficult with the resistance film method and the capacitance method, is possible, it can be expected to be applied to a wider range of applications. Furthermore, in the optical sensor system, it has been proposed to use, for example, a light pen having a light source as input means (see Patent Document 4), and the input means can be diversified.

  For example, when an LCD is used as an image display panel, a method of using a backlight of the LCD as a light source for light detected by a photosensor has been proposed. In this method, the light of the backlight is reflected at the interface between the finger placed on the image display surface of the touch panel and the image display surface, and the finger touches when the reflected light senses the reflected light. The position is detected.

JP 2005-530996 A Special table 2007-522586 JP 61-3232 JP JP-A-2-214211

  As described above, the photosensor-type touch panel has many advantages such as excellent durability and multi-point input. However, optical sensor touch panels are difficult to detect changes in the amount of light received by an optical sensor even when a finger is placed on the touch panel in an environment where external light is insufficient, for example, in a dim environment. The problem was that the position was easily recognized incorrectly.

  Such a problem can be solved, for example, by using the above-described light pen, but if it is essential to use a special light pen for input, the scope of application of the touch panel is narrowed and convenience is also lacking. There is a tendency. The method using the reflected light of the backlight is also effective to some extent against the lack of external light. However, when black display (black display) is performed on the image display panel, a finger can be placed on the screen. Since the backlight cannot be reflected, the position touched by the finger cannot be recognized.

  Furthermore, since the conventional optical member has a slow return of deformation after being pressed, it can be sufficiently applied to a touch panel mainly operated by buttons such as ATM, but the touch panel requires a quick operation such as character input. In this case, if the pressed portion is slid while being pressed, the optical sensor does not recognize only the pressed portion but also recognizes the portion where the deformation of the optical member has not been restored, and the touch panel It may cause malfunction.

  The present invention has been made in view of such circumstances, and can be recognized by simple input means even in an environment where the external light is weak, and the deformation return (afterimage time) after pressing the optical member is reduced. An object of the present invention is to provide an optical member for a touch panel that can sufficiently reduce malfunction caused by being slow.

  In order to achieve the above object, the present invention includes first and second layers opposed to each other, and a spacer provided between the first layer and the second layer. An optical member for a touch panel is provided in which at least one of the layer and the second layer is formed from an elastic body containing a filler.

  In the optical member of the present invention, when the elastic body constituting the first layer and / or the second layer contains a filler, an effect that the return of deformation after pressing the optical member is accelerated can be obtained. Conceivable. As the reason why such an effect is obtained, the present inventors presume as follows. That is, when at least one of the first layer and the second layer is composed of an elastic body containing a filler, the surface of the layer containing the elastic body becomes non-smooth and is deformed by being pressed. It is considered that the stress to return to becomes stronger, or the inclusion of the filler increases the hardness of the elastic body and increases the stress to return the deformation to the original. In addition, the optical member of the present invention can maintain a distance between the first layer and the second layer appropriately by providing a spacer between the first layer and the second layer. It is thought that operation can be prevented.

  In the optical member of the present invention, the visible light transmittance at 380 to 780 nm of the first layer and / or the second layer is preferably 70% or more.

  Moreover, it is preferable that the average primary particle diameter of the said filler is 0.001-50 micrometers from a viewpoint of improving the transparency of the layer comprised with the elastic body containing a filler.

  Furthermore, it is preferable that content of the said filler is 0.01-50 mass parts with respect to 100 mass parts of solid content of an elastic body. Thereby, the malfunction caused by the afterimage time in the touch panel can be further reduced.

  According to the present invention, it is possible to recognize with a simple input means even in an environment where the external light is weak, and sufficiently reduce the malfunction caused by the slow return of deformation (afterimage time) after pressing the optical member. An optical member for a touch panel that can be provided can be provided.

It is an end view which shows one Embodiment of the touchscreen which mounted the optical member. It is an end view for demonstrating the function of an optical member. It is an end view for demonstrating the function of an optical member. It is an end view which shows one Embodiment of the manufacturing method of an optical member.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  FIG. 1 is an end view showing an embodiment of a touch panel including an optical member. A touch panel 100 shown in FIG. 1 includes a liquid crystal cell 4, a backlight 60 as a light source provided on one side of the liquid crystal cell 4, an optical member 1 provided on the other side of the liquid crystal cell 4, and a liquid crystal cell. 4 is mainly provided with an optical sensor 52 provided in 4 and a pair of polarizing plates 20 and 21 disposed to face each other with the liquid crystal cell 4 and the optical member 1 interposed therebetween.

  The liquid crystal cell 4 is provided on two glass substrates 23 and 24 arranged to face each other, a color filter 25 provided below the glass substrate 23 on the optical member 1 side, and a glass substrate 24 on the backlight 60 side. The thin film transistor 51 and the optical sensor 52, the insulating film 54 covering the thin film transistor 51 and the optical sensor 52, the transparent electrode 41, the alignment film 43, the liquid crystal layer 45, the alignment film 42, and the transparent film laminated on the insulating film 54. Electrode 40. A light shielding film 50 is provided between the glass substrate 24, the thin film transistor 51, and the optical sensor 52. A liquid crystal spacer 47 is provided between the alignment film 42 and the alignment film 43. On the glass substrate 23, the adhesion layer 31, the optical member 1, the adhesion layer 30, the phase difference plate 22, and the polarizing plate 20 are laminated in this order.

  A touch panel 100 illustrated in FIG. 1 is an input device that has a function as a liquid crystal display device and a function of detecting a position when a predetermined position on the screen S100 is touched with a finger or the like.

  The optical member 1 has a structure in which a first layer 11 and a second layer 12 are arranged to face each other and are separated by a sourer 13. The optical member 1 is a laminated sheet having a main surface S1 on the first layer 11 side and a main surface S2 on the second layer side. The optical member 1 is arranged in such a direction that the first layer 11 is positioned on the backlight 60 and the optical sensor 52 side.

  The first layer 11 and the second layer 12 are separated from each other by a spacer, and a gap 2 is formed between the first layer 11 and the second layer 12. The space 2 may be filled with air, filled with a stable and harmless gas such as nitrogen, helium and argon, or may be a vacuum.

  The spacer 13 may be independent of the first layer 11 and / or the second layer 12, or may be integrated with the first layer 11 and / or the second layer 12. In the case where the spacer 13 is integrated with the first layer 11 and / or the second layer 12, the spacer 13 is not formed in the first layer 11 and / or the second layer 12. The layer 11 and / or the second layer 2 may be formed at the same time, and after the first layer 11 and / or the second layer 12 is formed in advance, the first layer surface 11a and / or The surface 12a of the second layer and the spacer 13 may be adhered.

  2 and 3 are schematic views for explaining the function of the optical member 1. As shown in FIG. 2, when the screen S100 of the touch panel 100 is not pressed, part of the light emitted from the backlight 60 and entering the optical member 1 is reflected on the surface 11a of the first layer 11. The reflected light L1. Due to the difference in refractive index between the first layer and the gas in the gap 2, the light easily reflects or scatters on the surface 11a, and includes scattered light received by the photosensor 52 provided on the first main surface S1 side. The amount of reflected light is relatively large.

  As shown in FIG. 3, when a predetermined position on the screen S100 of the touch panel 100 is touched by the finger F, the optical member 1 is pressed from the main surface S2 side. Thus, the second layer to which the mechanical pressure is locally applied is distorted toward the first layer side, and the first layer 11 and the second layer 12 are pressed against each other. At this time, when the spacer 13 is a hard material having no rubber elasticity, the first layer 11 and / or the second layer 12 is pushed into the spacer 13, and the surface 11a and / or the surface 12a is reversible. Transforms into Further, when the spacer 13 has rubber elasticity, the spacer 13 is crushed and deformed reversibly, and the surface 11a and / or the surface 12a is also reversibly deformed. As a result, at the position where the surface 11a of the first layer is pressed, the surface 11a and the surface 12a come into contact with each other, the light reflected or scattered there decreases, and the light that has entered the optical member 1 is mainly the finger F. Reflection occurs at the interface with the screen S100. The amount of reflected light L2 reflected at the interface between the finger F and the screen S100 is generally smaller than the amount of reflected light L1. Moreover, the light quantity or the brightness | luminance of the light which permeate | transmits an optical member becomes large. In this state, the amount of light received by the optical sensor 52 is often smaller than when the optical member 1 is not pressed.

  Thus, when the optical member 1 is pressed from the main surface S2 side, the amount of reflected light of the light incident from the main surface S1 side changes. By detecting this optical change using an optical sensor provided on the main surface S1 side, it is possible to recognize a predetermined position where the touch panel 100 is touched. Further, since the optical member 1 is provided between the polarizing plate 20 on the screen S100 side and the backlight 60, the backlight light and the reflected light thereof can be transmitted even during black display as in white display. It can be used efficiently.

  The optical sensor 52 is not particularly limited as long as it can detect an optical parameter of reflected light such as the amount of light. Specific examples include semiconductor elements that exhibit a photoelectric effect, such as amorphous silicon and polycrystalline silicon.

  At least one of the first layer 11 and the second layer 12 has rubber elasticity, and is formed from an elastic body containing a filler. The first layer 11 of the optical member 1 preferably has rubber elasticity capable of reversible deformation with respect to mechanical pressure. Since the first layer 11 has rubber elasticity, when the optical member 1 is pressed, the surface 11a easily deforms reversibly. Also from the viewpoint of durability of the touch panel, it is preferable that at least one of the first layer and the second layer has rubber elasticity.

  From the viewpoint of durability of the touch panel, operability, prevention of malfunction, and the like, the compression elastic modulus of the first layer 11 and / or the second layer 12 is preferably 0.01 to 100 MPa. When the compression modulus is less than 0.01 MPa, the surface is deformed even when no mechanical pressure is applied, and reflection and scattering of light incident from the light source tend not to occur. When the compression elastic modulus exceeds 100 MPa, the surface 11a and / or the surface 12a are not easily deformed when pressed with a weak pressure, and thus it is difficult to convert a change in mechanical pressure into an optical change. There is. From the same viewpoint, the compressive elastic modulus is more preferably 0.05 to 90 MPa, further preferably 0.1 to 80 MPa, more preferably 0.5 to 70 MPa, and even more preferably 1 to 60 MPa. It is preferably 1 to 10 MPa, particularly preferably.

The compression modulus is obtained from the slope of a load-displacement curve measured by a compression test under the following conditions using an ultra micro hardness meter.
Sample film thickness: 100 μm (compressed in the thickness direction)
Temperature: 25 ° C
Maximum pressure: 0.1 mN / μm ²
Measurement time: 20 seconds Indenter: Circular flat indenter (diameter: 50 μm)

  The surface 11a of the first layer 11 and the surface 12a of the second layer 12 have a flat shape in FIG. 1, but as long as a part of incident light can be reflected or scattered, the shapes are as follows. The shape is not particularly limited, and may be a non-flat shape having unevenness. From the viewpoint of maintaining good display quality as a touch panel, the surface 11a and the surface 12a are preferably flat, but the light incident from the backlight 60 is particularly efficiently reflected and can be effectively detected by the optical sensor 52. Therefore, the surface 11a and the surface 12a may have a non-flat shape. It is preferable that the maximum height of the non-flat shape (the maximum value of the height difference between the top of the convex portion and the bottom of the concave portion in a cross section having a predetermined length (for example, 10 mm)) is 0.01 to 3 μm. Further, the position where the touch panel 100 is touched can be recognized with higher sensitivity. From the same viewpoint, the maximum height of the non-flat shape is more preferably 0.1 to 2.5 μm, further preferably 0.3 to 2 μm, and preferably 0.5 to 1.5 μm. More preferably, it is especially preferable that it is 0.7-1.3 micrometers. Moreover, from the same viewpoint, the distance between the vertices of adjacent convex portions is preferably 0.01 to 15 μm, more preferably 0.1 to 10 μm, and preferably 0.5 to 9 μm. More preferably, it is more preferable that it is 0.7-7 micrometers, and it is especially preferable that it is 1-5 micrometers.

  The first layer 11 and the second layer 12 are preferably layers with high transparency. The higher the transparency of these layers, the more efficiently an optical change converted from a mechanical change caused by pressing can be detected, and an excellent display quality as a display device can be obtained. Specifically, it is preferable that the visible light transmittance of the double-sided flat film having a thickness of 20 μm formed of the material constituting the first layer 11 or the second layer 12 is 70 to 100%, and 75%. More preferably, it is more preferably 80% or more, still more preferably 83% or more, and particularly preferably 85% or more. Such visible light transmittance is a change in visible light transmittance before and after pressing, which will be described later, using a double-sided flat film formed using the material constituting the first layer 11 or the second layer 12. It can be measured by the same method as the measurement method.

  From the viewpoint of effectively expressing the light amount change before and after the deformation of the surface 11a, the absolute value of the difference in refractive index between the first layer 11 and the second layer 12 is preferably 0 to 0.1. From the same viewpoint, when the air gap 2 is formed between the first layer and the second layer as in this embodiment, the refractive index of the first layer 11 and the second layer 12 is 1.3. The above is preferable. These refractive indexes are measured by a known method such as a prism coupling method or a spectroscopic ellipsometry method.

  As a constituent material of the first layer 11 and / or the second layer 12 having rubber elasticity, various elastomers are preferable. Specific examples of suitable elastomers include natural rubber, synthetic polyisoprene, styrene and butadiene copolymer, butadiene and acrylonitrile copolymer, butadiene and alkyl acrylate copolymer, butyl rubber, bromobutyl rubber, chlorobutyl rubber, neoprene (chloroprene, 2-chloro -1,3-butadiene), olefin rubber (for example, ethylene propylene rubber (EPR) and ethylene propylene genomonomer (EPDM) rubber), nitrile elastomer, polyacrylic elastomer, polysulfide polymer, silicone rubber, thermoplastic elastomer, thermoplastic Copolyester, engineered acrylic elastomer, vinyl acetate ethylene copolymer, epichlorohydrin, chlorinated polyethylene, chemically crosslinked poly Styrene, chlorosulfonated polyethylene, fluorocarbon rubbers, and fluorosilicone rubbers. These may be used alone or in combination of two or more. Among these materials having rubber elasticity, silicone rubber is particularly preferable from the viewpoint of excellent surface shape deformability and reversibility when the optical member 1 is pressed.

  Examples of the silicone rubber include peroxide vulcanization type silicone rubber, addition reaction type silicone rubber, photoreactive type silicone rubber, and photo radical polymerization reaction type silicone rubber. Peroxide vulcanized silicone rubber is prepared by blending an organic peroxide with a silicone raw rubber made of linear highly polymerized polyorganosiloxane and heating it to crosslink the silicone raw rubber to form a rubber elastic body. can get. The addition reaction type silicone rubber is obtained by a method of forming a rubber elastic body by performing cross-linking by addition reaction between polyorganosiloxane having an aliphatic unsaturated hydrocarbon group and polyorganohydrogensiloxane in the presence of a platinum catalyst. It is done. The photoreactive silicone rubber is obtained by a method in which an epoxy group-containing polyorganosiloxane is crosslinked by irradiating light in the presence of a photoacid generator to form a rubber elastic body. The photoradical polymerization reaction type silicone rubber is obtained by a method of forming a rubber elastic body by crosslinking an acryloyl group-containing polyorganosiloxane by light irradiation in the presence of a photopolymerization initiator.

  The polyorganosiloxane used for forming the addition reaction type silicone rubber has two or more monovalent aliphatic unsaturated hydrocarbon groups bonded to silicon atoms in one molecule. Examples of the monovalent aliphatic unsaturated hydrocarbon group include a vinyl group, an allyl group, a 1-butenyl group, and a 1-hexenyl group. From the viewpoints of easy synthesis, fluidity of the composition before curing, and good heat resistance of the composition after curing, a vinyl group is most preferable. Furthermore, the monovalent aliphatic unsaturated hydrocarbon group may be present either at the end or in the middle of the polyorganosiloxane molecular chain, or may be present in both of them. However, in order to give excellent mechanical properties to the composition after crosslinking, the polyorganosiloxane preferably has a monovalent aliphatic unsaturated hydrocarbon group at both ends of the molecular chain.

  Other organic groups bonded to the silicon atom of the polyorganosiloxane include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl and dodecyl, aryl groups such as phenyl, benzyl, 2- Examples include aralkyl groups such as phenylethyl and 2-phenylpropyl, and substituted hydrocarbon groups such as chloromethyl, chlorophenyl, 2-cyanoethyl, and 3,3,3-trifluoropropyl. Among these, a methyl group is most preferable from the viewpoint of easy synthesis and excellent balance of properties such as fluidity before crosslinking and compression elastic modulus of the formed rubber elastic body.

  The polyorganosiloxane may be linear or branched. The degree of polymerization of the polyorganosiloxane is not particularly limited, but the composition before cross-linking has good fluidity and workability, and the composition after cross-linking has an appropriate compression modulus at 25 ° C. The viscosity is preferably 500 to 500,000 MPa · s, particularly preferably 1000 to 100,000 MPa · s.

  The polyorganohydrogensiloxane used for forming the addition reaction type silicone rubber is obtained by adding a hydrosilyl group contained in a molecule to a monovalent aliphatic unsaturated hydrocarbon group in the polyorganosiloxane. Functions as a crosslinking agent for siloxane. In order to efficiently form a network structure, the polyorganohydrogensiloxane preferably has at least three hydrogen atoms bonded to silicon atoms. Examples of the organic group bonded to the silicon atom of the siloxane unit include the same organic groups other than the monovalent unsaturated aliphatic hydrocarbon group in the polyorganosiloxane, and among these, from the viewpoint of easy synthesis The methyl group is most preferred. Further, the siloxane skeleton in the polyorganohydrogensiloxane may be any of linear, branched and cyclic, or a mixture thereof. The degree of polymerization of the polyorganohydrogensiloxane is not particularly limited, but it is difficult to synthesize a polyorganohydrogensiloxane in which two or more hydrogen atoms are bonded to the same silicon atom. It is preferable to have the above siloxane units.

  The compounding amount of the polyorganohydrogensiloxane is 0.5 to 0.5 hydrogen atoms bonded to silicon atoms in the polyorganohydrogensiloxane with respect to one monovalent aliphatic unsaturated hydrocarbon group in the polyorganosiloxane. The amount is preferably 5 pieces, preferably 1 to 3 pieces. When the abundance ratio of hydrogen atoms is less than 0.5, crosslinking tends to be incomplete. When the abundance ratio exceeds 5, the foaming is likely to occur during crosslinking, and the surface state is There is a tendency to decrease.

  The addition reaction type silicone rubber contains a platinum compound as a catalyst for accelerating the addition reaction between the monovalent aliphatic unsaturated hydrocarbon group in the polyorganosiloxane and the hydrosilyl group of the polyorganohydrogensiloxane. It is preferable to use it. Examples of platinum compounds include chloroplatinic acid, reaction products of chloroplatinic acid and alcohol, platinum-olefin complexes, platinum-vinylsiloxane complexes, and platinum-phosphine complexes. From the viewpoint of good solubility in polyorganosiloxane and polyorganohydrogensiloxane and good catalytic activity, a reaction product of chloroplatinic acid and alcohol and a platinum-vinylsiloxane complex are preferred. The compounding amount of the platinum-based compound is preferably 1 to 200 ppm by mass, more preferably 1 to 100 ppm by mass, and 2 to 50 ppm by mass in terms of platinum atoms with respect to the polyorganosiloxane. Particularly preferred. If the amount is less than 1 ppm by mass, the curing rate is insufficient, and the production efficiency of the optical member tends to decrease. If the amount exceeds 200 ppm by mass, the crosslinking rate is excessively increased, so that each component is blended. Workability tends to be impaired.

  In the optical member 1 according to the present embodiment, the elastic body constituting the first layer 11 and / or the second layer 12 contains a filler, so that the deformation can be quickly returned after pressing the optical member. An effect is obtained.

  As said filler, an inorganic filler and / or an organic filler are used. Examples of the inorganic filler include silica, aluminum silicate, titanium oxides such as anatase type titanium oxide and rutile type titanium oxide, alumina (aluminum oxide), calcium carbonate, antimony trioxide, barium titanate, calcium titanate, titanium. Examples thereof include carbides such as strontium acid, talc, clay, wollastonite, kaolin, mica, ceramic beads, zinc oxide, zirconium dioxide, silicon carbide, boron carbide and diamond carborundum, and nitrides such as boron nitride. Examples of the organic filler include acrylic resin, silicone resin, epoxy resin, amide resin such as nylon 6, nylon 66, nylon 11 and nylon 12, polystyrene resin, phenol resin, melamine resin, polyolefin resin, polyethylene resin, and cellulose. Mention may be made of resins, polyurethane resins and urea resins. Carbon black can also be used. As the filler, a transparent filler is preferably used from the viewpoint of hardly reducing the light transmittance of the optical member, and a silica filler is particularly preferable from the viewpoint of excellent compatibility with the silicone rubber.

  The average primary particle size of the filler according to this embodiment is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm, and still more preferably 0.001 to 1 μm. When the average primary particle size of the filler is less than 0.001 μm, the effect of shortening the afterimage time of the optical member is poor. When the filler is larger than 50 μm, the afterimage time of the optical member is shortened, but the optical member is touched. The display quality when mounted on the PC tends to deteriorate. The elastic body may contain only one type of filler having a certain average primary particle size, or may contain two or more types of fillers having different average primary particle sizes.

  The filler content is preferably 0.01 to 50 parts by mass and more preferably 0.05 to 30 parts by mass with respect to 100 parts by mass of the solid content of the elastic body. When the filler content is less than 0.01 parts by mass, it is difficult to achieve the effect of the present invention that the afterimage time can be shortened. When the filler content is more than 50 parts by mass, the visible light transmittance decreases. Therefore, it is difficult to be suitable as an optical member.

  The thickness of the first layer 11 and / or the second layer 12 (when the first layer 11 and / or the second layer 12 and the spacer 13 are integrated, the spacer 13 is excluded in the thickness direction. The thickness of the corresponding portion is preferably 1 to 500 μm. When the film thickness of the first layer 11 and / or the second layer 12 is less than 1 μm, when the optical member is pressed from one main surface side, the state of the reflected light reflected there hardly changes and is high. The position of the first layer 11 and / or the second layer 12 tends to be unrecognizable due to sensitivity and accuracy. When the thickness exceeds 500 μm, pressure transmission is weakened when pressure is applied to the optical member. Tend to be difficult to change. From the same viewpoint, the film thickness of the first layer 11 and / or the second layer 12 is more preferably 5 to 400 μm, further preferably 10 to 300 μm.

  From the viewpoint that when the optical member 1 is pressed, it is effectively deformed by a mechanical pressure, and either one of the first layer 11 and / or the second layer 12 is hard that does not substantially exhibit elasticity. It can also be composed of various materials. Specifically, it may be composed of an inorganic material selected from glass and ceramics, or an organic material selected from triacetyl cellulose, polyether sulfone, polyethylene terephthalate and polyether naphthalate, hard silicone resin, and acrylic resin.

  The spacer 13 may have rubber elasticity capable of reversible deformation with respect to mechanical pressure as described above. Since the spacer 13 has rubber elasticity, when the optical member 1 is pressed, the spacer 13 is easily and reversibly deformed. From the viewpoint that the position can be recognized with durability and high sensitivity of the touch panel, the spacer preferably has rubber elasticity. In addition, from the viewpoint that the optical member according to the present invention can be efficiently manufactured with good workability, the spacer 13 is simultaneously formed as a part of the first layer 11 and / or the second layer 12. In this case, the spacer is made of the same material as the first layer 11 and / or the second layer 12. When the first layer 11 and the second layer 12 and the spacer 13 are formed of an elastic body containing a filler, the afterimage time can be further increased, and thus the malfunction of the touch panel is further suppressed. Can do.

  The material constituting the spacer 13 is preferably various elastomers. Specific examples of suitable elastomers include all materials suitably used for the first layer 11 and / or the second layer 12 described above. In addition, among the above-described specific materials, all materials selected as preferable materials for the first layer 11 and / or the second layer 12 are listed as preferable constituent materials for the spacer 13 from the same viewpoint.

  From the viewpoint of durability of the touch panel, operability, prevention of malfunction, and the like, the compression elastic modulus of the spacer 13 is preferably 0.01 to 100 MPa. When the compression modulus is less than 0.01 MPa, the surface is deformed even when no mechanical pressure is applied, and reflection and scattering of light incident from the light source tend not to occur. When the compression elastic modulus exceeds 100 MPa, the surface 11a is not easily deformed when pressed with a weak pressure, so that it is difficult to convert a change in mechanical pressure into an optical change. From the same viewpoint, the compression modulus is more preferably 0.05 to 90 MPa, further preferably 0.1 to 80 MPa, further preferably 0.5 to 70 MPa, and 1 to 60 MPa. It is even more preferable that the pressure is 1 to 10 MPa.

  From the viewpoint that when the optical member 1 is pressed from the one main surface side, the state of the reflected light reflected therein changes efficiently, and the position can be recognized with higher sensitivity and accuracy. The height is preferably 1 to 80 μm. If the height of the spacer 13 is less than 1 μm, the surface 11a of the first layer and the surface 12a of the second layer are likely to come into contact with each other even when no mechanical pressure is applied, and malfunction tends to occur. . If the height of the spacer 13 exceeds 80 μm, the surface 11a and the surface 12a are difficult to contact when pressed with a weak pressure, and the pressed position tends to be difficult to recognize. From the same viewpoint, the height of the spacer 13 is more preferably 5 to 75 μm, further preferably 10 to 70 μm, still more preferably 13 to 65 μm, and still more preferably 15 to 60 μm. It is particularly preferably 17 to 55 μm, particularly preferably 20 to 50 μm.

  From the viewpoint that the surface 11a of the first layer and the surface 12a of the second layer can be stably separated from each other via the spacer 13, and from the viewpoint that display quality when the touch panel is formed can be maintained. The maximum width is preferably 1 to 300 μm. When the maximum width of the spacer 13 is less than 1 μm, the surface 11a of the first layer and the surface 12a of the second layer are easily in contact with each other even when no mechanical pressure is applied, and a malfunction is likely to occur during operation of the touch panel. Tend to be. When the maximum width of the spacer 13 exceeds 300 μm, the surface 11a and the surface 12a are difficult to contact when pressed with a weak pressure, and it is difficult to recognize the pressed position. , Its display quality tends to deteriorate. From the same viewpoint, the maximum width of the spacer 13 is more preferably 5 to 250 μm, further preferably 7 to 200 μm, still more preferably 10 to 150 μm, and still more preferably 15 to 100 μm. Preferably, it is very preferable that it is 17-70 micrometers, and it is especially preferable that it is 20-50 micrometers. As a result, the surface of the first layer and the surface of the second layer can be partially or completely stably separated from each other via the spacer, which can make it difficult for malfunctions to occur during operation of the touch panel. At the same time, the touch panel can be viewed with good display quality.

Similarly, from the viewpoint that the surface 11a of the first layer and the surface 12a of the second layer can be stably and effectively separated from each other via the spacer 13, and when a touch panel is obtained, From the viewpoint of maintaining good display quality, the number of spacers 13 per unit area on the surface 11a of the first layer is preferably ¹ to 300 / mm ² . When the number of the spacers 13 per unit area on the surface 11a of the first layer is less than 1 / mm ² , the surface 11a of the first layer and the surface 12a of the second layer even when no mechanical pressure is applied. Are likely to come into contact with each other, and a malfunction tends to occur when the touch panel is operated. If the number of spacers 13 per unit area on the surface 11a of the first layer exceeds 300 pieces / mm ² , the surface 11a and the surface 12a are difficult to come into contact with each other when pressed with a weak pressure. The display quality tends to be difficult to recognize, and when viewed as a touch panel, the display quality tends to deteriorate. From the same viewpoint, the number of the spacers 13 per unit area at the surface 11a of the first layer is more preferably from 5 to 250 pieces / mm ^2, further preferably from 7 to 200 pieces / mm ^2, It is more preferably 10 to 150 pieces / mm ² , still more preferably 15 to 130 pieces / mm ² , extremely preferably 17 to 100 pieces / mm ² , and 20 to 90 pieces / mm ^2. It is particularly preferred that

  The difference between the visible light transmittance when the optical member 1 is not pressed and the visible light transmittance when the optical member 1 is pressed (change in visible light transmittance before and after pressing) is 0.1 to 50. % Is preferred. If this difference is less than 0.1%, it tends to be difficult to detect an optical change when a mechanical pressure is applied by an optical sensor, and if it exceeds 50%, no mechanical pressure is applied. Therefore, it is necessary to increase the reflection or scattering in the first layer 11 or the second layer 12. If it does so, there exists a tendency for the display quality as a display apparatus to fall. From the same viewpoint, the change in visible light transmittance before and after pressing is more preferably 0.5 to 45%, still more preferably 1 to 40%, still more preferably 2 to 35, 3 to 30% is particularly preferable.

  The difference between the visible light transmittance when the optical member 1 is not pressed and the visible light transmittance when the optical member 1 is pressed (change in visible light transmittance before and after pressing) is 0.1 to 50. % Is preferred. If this difference is less than 0.1%, it tends to be difficult to detect an optical change when a mechanical pressure is applied by an optical sensor, and if it exceeds 50%, no mechanical pressure is applied. Therefore, it is necessary to increase the reflection or scattering in the first layer 11 or the second layer 12. If it does so, there exists a tendency for the display quality as a display apparatus to fall. From the same viewpoint, the change in visible light transmittance before and after pressing is more preferably 0.5 to 45%, still more preferably 1 to 40%, and even more preferably 2 to 35%. 3 to 30% is particularly preferable.

The change in visible light transmittance before and after pressing can be measured by the following procedures 1) to 7). Visible light means light in a wavelength region of 380 to 780 nm that is generally visible.
1) A sample in which an optical member is placed on a glass substrate and a disk-shaped glass plate having a diameter of 10 mm and a thickness of 0.7 mm is placed thereon is prepared.
2) irradiate the sample with light in the visible region in the normal direction, and measure the luminance a of the light transmitted through the sample in the range of the measurement viewing angle of 1 ° using a color luminance meter. The optical member is removed from the state, and the luminance b is measured in the same manner.
3) Visible light transmittance T1 when not pressed is calculated by the formula: T1 = (a / b) × 100 (%).
4) A sample similar to the above is prepared, and a load of 5 × 10 ³ Pa is applied between the glass substrate and the disk-shaped glass plate.
5) While applying a load to the sample, irradiate the sample with light in the visible region in the normal direction, and use a color luminance meter to determine the luminance c of the light transmitted through the sample in the range of the measurement viewing angle of 1 °. taking measurement. The optical member is removed from this state, and the luminance d is measured by the same method.
6) Visible light transmittance T2 when pressed is calculated by the formula: T2 = (c / d) × 100 (%).
7) The absolute value (ΔT) of the difference between the visible light transmittances T1 and T2 is obtained as the change in the visible light transmittance before and after pressing.

  The difference between the visible light reflectance when the optical member 1 is not pressed and the visible light reflectance when the optical member 1 is pressed (change in visible light reflectance before and after pressing) is 0.1 to 50. % Is preferred. If this difference is less than 0.1%, it tends to be difficult to detect an optical change when a mechanical pressure is applied by an optical sensor, and if it exceeds 50%, no mechanical pressure is applied. Therefore, it is necessary to increase the reflection or scattering in the first layer 11 or the second layer 12. If it does so, there exists a tendency for the display quality as a display apparatus to fall. From the same viewpoint, the change in the visible light reflectance before and after pressing is more preferably 0.5 to 48%, further preferably 1 to 45%, and further preferably 2 to 43%. It is preferably 3 to 40%, particularly preferably.

The change in visible light reflectance before and after pressing can be measured by the following procedure.
1) A 0.7 mm-thick glass substrate and a disk-shaped glass plate having a diameter of 10 mm and a thickness of 0.7 mm are placed on a white plate such as magnesium oxide, and rays in the visible region are normal to the white plate. The brightness a ′ of the light beam reflected at an angle of 25 ° with respect to the normal direction of the white plate is measured using a spectrocolorimeter or the like. Next, an optical member is placed between the glass substrate and the disk-shaped glass plate, and the brightness b ′ of the reflected light is measured by the same method.
2) The visible light reflectance R1 when the optical member is not pressed is calculated by the formula: R1 = (b ′ / a ′) × 100 (%).
3) The brightness c ′ of the reflected light is measured by the same method as in 1) while applying a load of 5 × 10 ³ Pa between the glass substrate and the disk-shaped glass plate.
4) The visible light reflectance R2 when the optical member is pressed is calculated by the formula: R2 = (c ′ / a ′) × 100 (%).
5) The absolute value (ΔR) of the difference between the visible light reflectances R1 and R2 before and after pressing is obtained as the change in the visible light reflectance before and after pressing.

  An intermediate layer having a refractive index different from that of the first layer 11 may be provided between the first layer 11 and the second layer 12. By providing the intermediate layer, it is possible to obtain a touch panel that is further excellent in durability against changes in the use environment as compared with the case where the gap 2 is formed.

  The absolute value (Δn) of the difference between the refractive index of the first layer 11 having the uneven surface 11a and the refractive index of the intermediate layer is preferably 0.01 to 1.0. When the absolute value of the refractive index difference is less than 0.01, the optical sensor cannot efficiently detect the reflected light from the optical member 1 when the optical member is not pressed. It tends to be difficult to recognize. Moreover, when the absolute value of the refractive index difference exceeds 1.0, it tends to be difficult to select a material having a refractive index necessary to achieve this. From the same viewpoint, the absolute value of the difference in refractive index is preferably 0.03 to 0.7, 0.05 to 0.5, 0.07 to 0.3, or 0.1 to 0.2. The refractive index is measured by a known method such as a prism coupling method or a spectroscopic ellipsometry method.

  The intermediate layer preferably has adhesiveness. The resin used for forming the adhesive intermediate layer is not particularly limited as long as it exhibits adhesiveness to the first layer or the second layer. For example, an acrylic resin, a cross-linked acrylic Examples include resins, acrylic monomers, silicone resins, fluororesins, and polyvinyl alcohol resins. These can be used alone or in combination of two or more.

  As the acrylic resin, a copolymer containing an unsaturated monomer exhibiting a low glass transition temperature is preferable. Examples of the unsaturated monomer exhibiting a low glass transition temperature include butyl acrylate, butyl methacrylate, ethyl acrylate, ethyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. Other unsaturated monomers used in the copolymer containing unsaturated monomers exhibiting a low glass transition temperature include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylic N-propyl acid, n-propyl methacrylate, iso-propyl acrylate, iso-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, acrylic acid sec-butyl, sec-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, 2-acrylic acid 2- Ethyl hexyl, metac 2-ethylhexyl phosphate, octyl acrylate, octyl methacrylate, nonyl acrylate, nonyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, tetradecyl methacrylate, hexadecyl acrylate, Hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, eicosyl acrylate, eicosyl methacrylate, docosyl acrylate, docosyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, cycloheptyl acrylate, methacrylic acid Cycloheptyl acid, benzyl acrylate, benzyl methacrylate, phenyl acrylate, phenyl methacrylate , Methoxyethyl acrylate, methoxyethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, 2-chloroethyl acrylate , 2-chloroethyl methacrylate, 2-fluoroethyl acrylate, 2-fluoroethyl methacrylate, styrene, α-methylstyrene, cyclohexylmaleimide, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, vinyl toluene, vinyl chloride , Vinyl acetate, N-vinylpyrrolidone, butadiene, isoprene and chloroprene. These can be used alone or in combination of two or more.

  The cross-linked acrylic resin is a copolymer containing an unsaturated monomer having a functional group such as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, and acrylonitrile as a copolymerization component. Is crosslinked with a crosslinking agent.

  As said crosslinking agent, well-known crosslinking agents, such as an isocyanate type, a melamine type, and an epoxy type, can be used. Further, as the crosslinking agent, a polyfunctional crosslinking agent such as trifunctional or tetrafunctional is more preferably used in order to form a network structure that gradually spreads in the crosslinked acrylic resin.

  The weight average molecular weight (measured by gel permeation chromatography and converted to standard polystyrene) of the acrylic resin and the copolymer used to obtain the crosslinked acrylic resin is the first layer 11 or the second layer. From the viewpoint of adhesiveness to the layer 12, it is preferably 1000 to 300000, and more preferably 5000 to 150,000.

  A monomer having a tackiness can be used from the viewpoint of expressing high fluidity and effectively deforming the surface shape of the first layer or the second layer. Examples of the monomer include polyethylene glycol diacetate, polypropylene glycol diacetate, urethane monomer, nonylphenyl dixylene acrylate, nonylphenyl dixylene methacrylate, γ-chloro-β-hydroxypropyl-β′-acryloyloxyethyl-o. -Phthalate, γ-chloro-β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-methacryloyloxyethyl -O-phthalate, β-hydroxypropyl-β'-acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate, o-phenylpheno An unsaturated monomer used for luglycidyl ether acrylate, o-phenylphenol glycidyl ether methacrylate, or acrylic resin can be used. These can be used alone or in combination of two or more.

  The glass transition temperature (Tg) of the intermediate layer is preferably −20 ° C. or lower. When the glass transition temperature of the intermediate layer is higher than −20 ° C., the adhesiveness is lowered, and there is a tendency that an appropriate adhesive force to the first layer 11 and the second layer 12 cannot be obtained.

  The thickness of the intermediate layer is preferably 1 to 50 μm. When the thickness of the intermediate layer is less than 1 μm, there is a tendency to entrap bubbles when laminating the first layer or the second layer. When the thickness exceeds 50 μm, pressure is transmitted when the touch panel is touched. Since it becomes difficult, there exists a tendency for the surface shape of the 1st layer 11 to become difficult to change. From the same viewpoint, the thickness of the intermediate layer is more preferably 2 to 40 μm, and further preferably 3 to 30 μm.

  You may use the optical member 1 in the state of the laminated body which comprises a support body film and the optical member 1 provided on this support body film. Examples of the support film include a film having a thickness of about 5 to 100 μm made of polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polyethersulfone, and triacetyl cellulose.

  A resin layer having adhesiveness or adhesiveness may be provided between the support film and the first layer 11 or the second layer 12.

  A cover film may be further laminated on the first layer 11 or the second layer 12. Examples of the cover film include films having a thickness of about 5 to 100 μm made of polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, triacetyl cellulose, and the like. A resin layer having adhesiveness or adhesiveness may be provided between the cover film and the first layer 11 or the second layer 12.

  FIG. 4 is an end view showing an embodiment of a method for manufacturing the optical member 1. The manufacturing method shown in FIG. 4 includes a step of forming a first layer 11 having a surface 11a having a convex spacer 13 transferred from a surface having a concave portion on a surface having a concave portion of a mold 7, A step of peeling the first layer 11 from the mold 7, and a step of laminating the second layer 12 on the surface of the spacer 13 integrated with the peeled first layer 11.

  As shown in FIG. 4 (a), a liquid material containing the components constituting the first layer 11 is applied onto the surface having the concave portions of the mold 7 using the roll 8. The applied liquid material is changed into a solid state by heat or light (FIG. 4B). Thereafter, the first layer 11 is peeled off from the mold 7 (FIG. 4C). Instead of this method, the liquid material 11 for forming the first layer is applied to a flat substrate, and a mold having a surface on which a recess is formed is pressed, and the liquid material is solidified in that state. It is also possible to adopt a method of changing.

  By laminating another mold having a concave surface on the liquid material 11 applied on the mold 7 and changing the liquid material into a solid state in that state, the first layer 11 having both concave and convex shapes is formed. It can also be obtained.

  The mold 7 is a film having a large number of fine recesses formed on the surface. As the mold 7, for example, by a method in which an original mold having a convex surface is pressed against a photosensitive resin composition layer formed on a flat support film, and the photosensitive resin composition layer is photocured in that state. Obtainable. Moreover, it can also obtain by the method of pressing the flat surface of a film directly on the original | mold which has a convex part surface, and transferring a concave part to the film surface. Or a recessed part can also be formed in the photosensitive resin composition layer formed on the flat support body film with the photolithographic method.

  The above-mentioned prototype is, for example, a photoresist applied on a glass plate is exposed and developed using a photomask having a predetermined mask pattern, or laser-cutting to form a resist pattern, and a vacuum evaporation method is formed there It can be obtained by forming a metal film such as silver or nickel (conducting treatment) by sputtering or the like, laminating a metal such as copper and nickel by electroforming, and then peeling the metal film from the glass plate. . At this time, the shape of the convex portion can be controlled to a random shape, a line shape, a rectangular shape, a prismatic shape, a cylindrical shape, a dot lens shape, a cylindrical lens shape, etc. depending on the mask pattern shape or the resist pattern shape. The shape of the convex portion is transferred as a spacer 13 to the surface of the first layer 11.

  By performing metal plating such as copper or nickel on the surface of the conductive metal, a prototype in which a large number of fine recesses are formed on the surface can be produced. The prototype can also be produced by a method in which a diamond indenter is pressed against a smooth prototype substrate such as stainless steel. At this time, the diamond indenter is pressed while moving the original substrate in the horizontal direction, or the indenter is pressed while moving the indenter while the original substrate is stationary, so that it is flat, spherical or curved. It is possible to form a large number of recesses having a part of By selecting the shape of the diamond indenter, it is possible to control to a random shape, a line shape, a rectangular shape, a prismatic shape, a cylindrical shape, a dot lens shape, a cylindrical lens shape, and the like. In this case, the prototype may be a flat plate or a roll having a curved surface. Moreover, the recessed part may be arrange | positioned at random and may be arrange | positioned according to the defined rule.

  As a method for applying the liquid material 11 for forming the first layer 11, a known application method can be used. For example, doctor blade coating method, Mayer bar coating method, roll coating method, screen coating method, spinner coating method, ink jet coating method, spray coating method, dip coating method, gravure coating method, curtain coating method, die coating method, etc. .

  If the liquid for forming the first layer contains a solvent, it can be applied and then dried to remove the solvent.

  The optical member thus obtained can be stored in a roll or stored.

  An optical member having an intermediate layer is formed by forming the first layer or the second layer on a support film, and applying a solution containing the components constituting the intermediate layer on the portion other than the spacer by the above-mentioned known method. And if necessary, after drying, it can obtain by the method of laminating | stacking a 1st layer or a 2nd layer on an intermediate | middle layer.

  The touch panel 100 includes, for example, a step of laminating the optical member 1 on one side of the liquid crystal cell 4, a step of laminating the retardation plate 22 and the polarizing plate 20 on the optical member 1, and the other side of the liquid crystal cell 4. And providing the polarizing plate 21 and the backlight 60 in this order.

  When a cover film is present on the optical member 1, the adhesive film 31 is placed on the liquid crystal cell 4 in such a direction that the first layer 11 is located on the liquid crystal cell 4 side after the cover film is removed. Through the liquid crystal cell 4. In the case of lamination, it is preferable to perform pressure bonding with a pressure roll.

  The pressure roll may be provided with a heating means so that it can be heat-pressure bonded. 10-100 degreeC is preferable, as for the heating temperature in the case of thermocompression bonding, 20-80 degreeC is more preferable, and 30-60 degreeC is still more preferable. When the heating temperature is less than 10 ° C., the adhesion between the optical member 1 and the liquid crystal cell 4 tends to decrease, and when the heating temperature exceeds 100 ° C., the liquid crystal cell 4 tends to deteriorate.

In addition, the pressure at the time of thermocompression bonding is preferably 50 to 1 × 10 ⁵ N / m, more preferably 2.5 × 10 ^{2 to} 5 × 10 ⁴ N / m in terms of linear pressure, and 5 × 10 ² to 4 × 10 ⁴ N / m is more preferable. If this pressure is less than 50 N / m, the adhesion between the optical member 1 and the liquid crystal cell 4 tends to decrease. If it exceeds 1 × 10 ⁵ N / m, the liquid crystal cell 4 may be destroyed. Get higher.

  The retardation plate 22 and the polarizing plate 20 can also be laminated on the optical member 1 by the same method as described above. Moreover, the polarizing plate 21 can be laminated | stacked on the opposite side to the optical member 1 of the liquid crystal cell 4 with the same method.

  There is no restriction | limiting in particular as a method of mounting the backlight 60 in the liquid crystal cell 4, A well-known method can be utilized. Examples of the method include incorporating the backlight 60 and the liquid crystal cell 4 into a housing for constituting a module, or thermocompression bonding with a sealing material. The backlight 60 includes, for example, a light emitting diode, a light guide plate, a reflection plate, and a diffusion plate.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in full detail, this invention is not limited by this.

Production of mold for forming first layer and spacer First, 60 parts by mass of methacrylic acid / methyl methacrylate / ethyl acrylate (mass ratio: 17/53/30) copolymer, 17 parts by mass of pentaerythritol triacrylate, 1,9 -20 parts by mass of nonane diacrylate, 2- (2-chlorophenyl) -1- [2- (2-chlorophenyl) -4,5-diphenyl-1,3-diazol-2-yl] -4,5-diphenylimidazole A photosensitive resin solution was prepared by dissolving 2.7 parts by mass and 0.3 part by mass of N, N′-tetraethyl-4,4′-diaminobenzophenone in 100 parts by mass of methyl ethyl ketone.

  The photosensitive resin solution is uniformly coated on a polyethylene terephthalate (PET) film having a thickness of 50 μm using a comma coater, and dried for 5 minutes with a hot air convection dryer at 100 ° C. to form a film made of a photosensitive resin. A photosensitive layer having a thickness of 38 μm was formed.

The obtained photosensitive layer is 1 mm thick, 10 cm long × 10 cm wide using a laminator (manufactured by Hitachi Chemical Co., Ltd., trade name: HLM-3000 type), roll temperature of 120 ° C., substrate feed rate. Laminate under conditions of 1 m / min, pressure bonding pressure (cylinder pressure) 4 × 10 ⁵ Pa (linear pressure 9.8 × 10 ³ N / m), and produce a substrate in which a photosensitive layer and a PET film are laminated on a glass substrate did.

Next, a parallel light exposure machine (manufactured by Oak Manufacturing Co., Ltd.) was used for the photosensitive layer through the PET film surface of the obtained substrate, using a photomask in which actinic light shielding portions having a diameter of φ30 μm were irregularly arranged. , EXM1201) was used to imagewise irradiate ultraviolet rays with an exposure amount of 1 × 10 ² J / m ² (measured value at i-line (wavelength 365 nm)) from above the photomask surface. Next, the PET film is peeled off, and spray development is performed at 30 ° C. for 60 seconds using a 1% by mass Na ₂ CO ₃ aqueous solution to remove a part of the photosensitive layer and form irregularly arranged concave portions in the photosensitive layer did. The photosensitive layer in which the concave portion was formed was heated at 230 ° C. for 30 minutes with a box type dryer, and this was used as a mold for forming the first layer and the spacer. In addition, as a result of observing the obtained type | mold using the laser microscope "VK-8510" by Keyence Corporation, it has 70 recessed parts / mm < ² >, the recessed part shape is 30 micrometers in diameter and 30 micrometers in depth. Met.

Example 1
Production of first layer (L-1) and spacer (SP-1) On the mold having the above-mentioned recess, "TSE3032 (A)" (momentive performance materials Japan GK) is an addition reaction type silicone. , Trade name) 100 parts by mass and “TSE 3032 (B)” 10 parts by mass, silica sol “IPA-ST” (silica filler (average primary particle size 0.015 μm) 40% by mass isopropanol solution, Nissan Chemical Co., Ltd.) A silicone resin solution in which 55 parts by mass of product and trade name) and 55 parts by mass of hexane (Wako Pure Chemical Industries, Ltd.) were mixed was uniformly applied using a comma coater. Then, vacuum degassing is performed, and the silicone rubber is cured by heating at 75 ° C. for 20 minutes on a hot plate, so that the solid silicone rubber layer that becomes the first layer (L-1) and the spacer (SP-1) is obtained. Formed.

  Also, a 50 μm thick triacetyl cellulose (TAC) film is prepared, and “ME151” (made by Momentive Performance Materials LLC) is applied as a primer and dried at room temperature for 30 minutes to form a 10 μm thick adhesive layer. A TAC film was obtained.

Next, using a laminator “HLM-3000 type” (trade name, manufactured by Hitachi Chemical Co., Ltd.) so that the adhesive layer of the TAC film having the adhesive layer is in contact with the silicone rubber layer, a roll temperature of 25 ° C. And a feed rate of 1 m / min, and a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa). Next, the first layer and the mold for forming the spacer are removed, and the solid silicone rubber layer, the adhesive layer, and the TAC to be the first layer (L-1) having the convex spacer (SP-1). A laminate in which films were laminated in this order was obtained.

The film thickness of the first layer (L-1) obtained (the thickness of the portion excluding the spacer (SP-1)) was measured using a surface shape measuring device “Surf Coder SE-30D type” manufactured by Kosaka Laboratory. ”Was 80 μm. Moreover, as a result of measuring the height and maximum width of the formed spacer (SP-1) using a laser microscope “VK-8510” manufactured by Keyence Corporation, the height was 30 μm and the maximum width was 30 μm. . Furthermore, as a result of observing and measuring the number of spacers per unit area on the first layer with an optical microscope, the number of spacers (SP-1) was 70 / mm ² .

Production of Second Layer (L-2) First, “ME151” was applied to a TAC film having a thickness of 50 μm and dried at room temperature for 30 minutes to obtain a TAC film having an adhesive layer having a thickness of 10 μm. Next, the silicone resin solution is uniformly applied onto the TAC film having the adhesive layer using a comma coater, and is cured by heating for 10 minutes with a 75 ° C. hot air convection dryer to form a silicone rubber layer (second layer). (L-2)) was formed.

  It was 50 micrometers when the thickness of the silicone rubber layer which is the obtained 2nd layer (L-2) was measured using "Surf coder SE-30D type".

Production of optical member (I) On the surface having the spacer (SP-1) of the first layer (L-1) obtained above, the second layer (L-2) obtained above was laminated, The optical member (I) sandwiched between the TAC films was formed by heating for 60 minutes using a hot air convection dryer at 75 ° C. while being uniformly pressurized at a pressure of 3 × 10 ² Pa.

Evaluation of afterimage time A 5 cm square pressure-sensitive adhesive film (manufactured by Nitto Denko) was bonded to a 10 cm square glass plate, and the optical member (I) was bonded thereto. Finally, a polarizing plate (manufactured by Nitto Denko) was laminated so as to be in a crossed Nicol state to obtain a sample for evaluation. This sample was attached to the film physical property evaluation system “RE2-30005B” (trade name, manufactured by Yamaden Co., Ltd.), and the polarizing plate side of the sample was pressed with silicone rubber at 10 mm / s and released, Changes in luminance were collected from a luminance meter “BM-5A” (Topcon Co., Ltd., trade name), and the time elapsed with respect to the luminance changes at that time was “Memory HiCorder 8870” (manufactured by Hioki Electric Co., Ltd., trade name) ) Was used to estimate the afterimage time. The afterimage time was 200 ms.

The visible light transmittance of the double-sided flat film composed of the material constituting the first layer (L-1), the second layer (L-2) and the spacer (SP-1) constitutes the optical member (I). The above-mentioned silicone resin solution used for forming the first layer (L-1), the second layer (L-2), and the spacer (SP-1) is used on a flat surface of a PET film by using a comma coater. And uniformly heated and heated for 60 minutes in a hot air convection dryer at 75 ° C. to form a solid silicone rubber layer.

  The obtained silicone rubber layer was peeled from the PET film to obtain a single silicone rubber layer (thickness: 20 μm) for visible light transmittance evaluation having flat surfaces. This silicone rubber layer alone was laminated on a 0.7 mm thick glass substrate to prepare a sample for evaluating visible light transmittance. The sample is irradiated in the normal direction with respect to the sample using a LED backlight as a light source, and the sample is measured with a color luminance meter “BM-5A” manufactured by Topcon Co., Ltd. within a measurement viewing angle range of 1 °. The luminance A of the light beam that passed through was measured. From this state, only the silicone rubber layer alone was removed, and the luminance B was measured in the same manner. From the measured luminance A and luminance B, visible light transmission of a double-sided flat film formed from the material constituting the first layer (L-1), the second layer (L-2) and the spacer (SP-1) When the rate T (= A / B × 100 (%)) was determined, it was T = 85%.

(Example 2)
Silica resin solution containing silica filler (average primary particle size in the range of 0.01 to 0.1 μm, 30% by mass) “TSE3455 (A)”, an addition reaction type silicone (Momentive Performance Materials Japan GK Manufactured, trade name) 100 parts by mass, 10 parts by mass of “TSE3455 (B)” and 110 parts by mass of hexane, except that the silicone resin solution was mixed. ), A spacer (SP-2) and a second layer (L-4) were prepared and laminated to obtain an optical member (II).

  In the same manner as in Example 1, the estimated afterimage time was 47 ms, and the visible light transmittance was 86%.

(Example 3)
Silica resin solution containing silica filler (average primary particle size in the range of 0.01 to 0.1 μm, 15% by mass) addition reaction type silicone “TSE3466 (A)” (Momentive Performance Materials Japan GK The first layer (L-5) was prepared in the same manner as in Example 1 except that the product was changed to a silicone resin solution in which 100 parts by mass, 10 parts by mass of “TSE3466 (B)” and 110 parts by mass of hexane were mixed. ), A spacer (SP-3) and a second layer (L-6) were prepared, and these were laminated to obtain an optical member (III).

  In the same manner as in Example 1, the estimated afterimage time was 60 ms, and the visible light transmittance was 86%.

(Comparative Example 1)
100 parts by mass of “TSE3032 (A)” (product name, manufactured by Momentive Performance Materials Japan Godo Kaisha), which is an addition reaction type silicone, and 10 parts by mass of “TSE3032 (B)” and 110 parts by mass of hexane. A first layer (L-7), a spacer (SP-4), and a second layer (L-8) were prepared in the same manner as in Example 1 except that the silicone resin solution was mixed. Were laminated to obtain an optical member (IV).

  In the same manner as in Example 1, the estimated afterimage time was 760 ms, and the visible light transmittance was 86%.

The evaluation results of the obtained optical member are summarized in Table 1.

[Evaluation of touch panel function]
Example 4
Thin film transistor (TFT), optical sensor, light shielding film, wiring, insulating film, alignment film, electrode mounted substrate, color filter, black matrix, planarization film, transparent electrode, alignment film, sealing material, spacer material A liquid crystal cell for evaluation in which liquid crystal was sealed between both substrates was prepared. The optical member (I) was laminated on the liquid crystal cell for evaluation using a laminator “HLM-3000 type” (manufactured by Hitachi Chemical Co., Ltd.). At this time, the first layer (L-1) was laminated so that the TAC film surface of the first layer (L-1) was in contact with the substrate on which the color filter of the evaluation liquid crystal cell was formed. The lamination conditions at this time were a roll temperature of 25 ° C., a substrate feed rate of 1 m / min, and a pressure bonding pressure (cylinder pressure) of 1 × 10 ⁵ Pa.

  A retardation plate and a polarizing plate were sequentially laminated on the second layer (L-2) of the optical member (I) laminated on the evaluation liquid crystal cell by the same lamination method as described above. Moreover, the polarizing plate was laminated | stacked on the surface on the opposite side to the optical member (I) of the liquid crystal cell for evaluation by the lamination | stacking method similar to the above. Further, a backlight device provided with a light emitting diode was attached to the side opposite to the optical member (I) to produce a liquid crystal module for touch panel function evaluation.

  This liquid crystal module was connected to a drive circuit and driven by a program that developed a touch panel function. Then, when the liquid crystal screen is touched from the optical member (I) side using a non-conductive pen in a dark place, the position touched with the pen is recognized by the optical sensor, and an image as programmed without malfunction. was gotten. From this result, it was confirmed that the touch panel function operates without problems by mounting the optical member (I).

(Comparative Example 2)
A liquid crystal module for touch panel function evaluation was produced in the same manner as in Example 4 except that the comparative optical member (IV) obtained in Comparative Example 1 was used in place of the optical member (I).

  The obtained liquid crystal module was connected to a drive circuit, driven by a program for developing a touch panel function, and a liquid crystal screen was touched using a non-conductive pen in a dark place. However, although the position touched with the pen is recognized, when the pen is moved, the part before the pen is moved is also recognized, causing a malfunction in the program. That is, the liquid crystal module could not be operated normally as a touch panel. This is considered because the afterimage time of the optical member (IV) is long.

  DESCRIPTION OF SYMBOLS 1 ... Optical member, 2 ... Space | gap, 4 ... Liquid crystal cell, 11 ... 1st layer, 11a ... Surface of 1st layer, 12 ... 2nd layer, 12a ... Surface of 2nd layer, 13 ... Spacer, 20, 21 ... Polarizing plate, 22 ... Retardation plate, 23 ... Glass substrate, 24 ... Glass substrate, 25 ... Color filter, 30, 31 ... Adhesive layer, 40, 41 ... Transparent electrode, 42, 43 ... Alignment film, 45 DESCRIPTION OF SYMBOLS ... Liquid crystal layer, 47 ... Spacer, 50 ... Light-shielding film, 51 ... Thin film transistor, 52 ... Optical sensor, 54 ... Insulating film, 60 ... Backlight, 100 ... Touch panel, S1, S2 ... Main surface of optical member, S100 ... Screen .

Claims (4)

A first layer and a second layer disposed opposite to each other, and a spacer provided between the first layer and the second layer,
An optical member for a touch panel, wherein at least one of the first layer and the second layer is formed from an elastic body containing a filler.   The optical member according to claim 1, wherein visible light transmittance of the first layer and / or the second layer is 70% or more.   The optical member according to claim 1 or 2, wherein an average primary particle size of the filler is 0.001 to 50 µm.   The optical member according to any one of claims 1 to 3, wherein a content of the filler is 0.01 to 50 parts by mass with respect to 100 parts by mass of the solid content of the elastic body.

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