JP2012091406A - Transparent conductive laminated film and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive laminated film excellent in transparency and flexibility, and moreover, excellent in optical characteristics and capable of suppressing cracks or damage regardless of repetitive keying, in a resistive film type touch panel.SOLUTION: On one surface of a base material film formed of a transparent resin, a cushion layer formed of a hardened material of a polymerizable composition containing urethane (meth)acrylate, a functional layer, and a transparent conductive layer are formed sequentially in this order, thereby preparing the transparent conductive laminated film. The polymerizable composition is a composition with a tensile modulus of elasticity of 200 MPa or less in the hardened material with thickness of 100 μm hardened by an acceleration voltage of 200 kV and an electron beam with a quantity of irradiation of 50 kGy. Moreover, the polymerizable composition may further includes poly Calkylene glycol di(meth)acrylate. The thickness of the cushion layer exceeds 10 μm, and the thickness ratio between the base material film and the cushion layer may be the base material film/the cushion layer=20/1 to 5/1.

Description

  The present invention relates to a transparent conductive laminated film used for an upper electrode (a viewing-side electrode) of a resistive film type touch panel, and a touch panel provided with the laminated film.

  In recent years, with the advancement of electronic displays as man-machine interfaces, interactive input systems have become widespread. Among them, devices that integrate a touch panel (coordinate input device) with a display are ATMs (automated teller machines), merchandise management, Widely used in outworkers (diplomatic, sales), information display, entertainment equipment. Lightweight and thin displays such as liquid crystal displays can be made keyboard-less, and their features are alive, so the number of cases where touch panels are used in mobile devices is increasing. The touch panel can be classified into an optical method, an ultrasonic method, a capacitance method, a resistance film method, and the like according to a position detection method. Of these, the resistive film method is popular because of its simple structure and excellent price / performance ratio.

  A resistive touch panel is an electrical component in which two laminated films or plates having transparent electrodes (transparent conductive layers) on opposite sides are held at regular intervals. The operation method is that after fixing one transparent electrode, press the other transparent electrode with a pen or finger from the viewing side, bend it, and contact and conduct with the fixed transparent electrode. Is detected and a predetermined input is made. In particular, since the upper transparent electrode (transparent electrode on the viewing side) is repeatedly bent and used, the transparent conductive layer is cracked or damaged, and the detection circuit is likely to fail. Therefore, keying durability against repeated use is required. In particular, as the use of the touch panel has expanded to entertainment devices such as game machines, it is necessary to press the display screen thoroughly, but the upper electrode is curved more greatly at the edge of the screen than at the center. Therefore, a high keystroke durability (end-pressing durability) is required.

  Furthermore, in such a touch panel operation method, when pressing an electrode with a pen or a finger, a rainbow pattern (so-called “Newton ring”) is formed around the pointing jig such as the finger or the pen that is being pressed. Interference colors or interference fringes) may appear, reducing the visibility of the screen. Specifically, when two transparent electrodes contact or bend due to contact, and the distance between the two transparent electrodes facing each other is about the wavelength of visible light (about 0.5 μm), the two transparent electrodes Interference of reflected light occurs in the space between the electrodes, and Newton rings are generated. The occurrence of such a Newton ring is an unavoidable phenomenon on the principle of a resistive film type touch panel. Therefore, the film constituting the transparent electrode is required to have an anti-Newton ring property that is formed unevenly on the surface of the transparent electrode so that no Newton ring is generated.

As a transparent conductive laminate having improved flexibility of a transparent electrode substrate, Japanese Patent No. 2667680 (Patent Document 1) discloses a film thickness of 50 mm or more on one surface of a transparent film substrate having a thickness of 2 to 120 μm. A transparent conductive thin film is formed, and a transparent base material is attached to the other surface through a transparent adhesive layer having an elastic modulus of 1 × 10 ⁵ to 1 × 10 ⁷ dyn / cm ² and a thickness of 1 μm or more. A transparent conductive laminate is disclosed. In this document, acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, and rubber-based pressure-sensitive adhesive can be used as the pressure-sensitive adhesive layer, and the scratch resistance of the conductive thin film provided on one surface of the film base due to its cushioning effect. And a function of improving the hit point characteristics.

  However, since this transparent conductive laminate is manufactured by bonding through an adhesive, foreign matter and bubbles are likely to be mixed during the bonding process, and there is a problem in productivity, and it adheres to the bonding surface. Foreign substances and bubbles cannot be physically removed, and are liable to deteriorate optical characteristics and electrical characteristics. In addition, since the two films are rewound from the roll and laminated in the bonding, peeling charge is easily generated. Furthermore, in this laminate structure, a thin transparent substrate exists between the pressure-sensitive adhesive layer and the transparent conductive layer. For this reason, it becomes easy to curl if a thick layer such as an anti-Newton ring layer is formed on a thin transparent substrate. As a result, it becomes difficult to form a transparent conductive layer on a thin transparent substrate by vapor deposition, and it is also difficult to bond two films with an adhesive layer. Therefore, in such a configuration, an anti-Newton ring layer cannot be provided, and it cannot be used for a display device that requires visibility such as anti-Newton ring property and antiglare property. Further, since the curling is performed, a display device using the film having this structure cannot be enlarged.

  On the other hand, as a laminated sheet using a coating instead of a laminated sheet using bonding, in JP 2004-158253 A (Patent Document 2), a hard coat layer is formed on one surface of a polymer film, A transparent conductive film in which a transparent conductive thin film is formed on the other surface, a transparent conductive film in which a stress relaxation layer made of an acrylic resin is provided between the polymer film and the transparent conductive thin film is disclosed. Has been. However, this stress relaxation layer did not have sufficient keystroke durability.

  Patent No. 3972418 (Patent Document 3) discloses a transparent conductive film including a laminate formed in the order of a transparent plastic film layer / cushion layer / transparent resin layer / transparent conductive thin film layer, A transparent conductive film is disclosed in which the cushion layer is composed of a copolymerized polyester resin and a crosslinking agent, the dynamic hardness is 0.005 to 2, and the transparent resin layer is composed of a copolymerized polyester or a polyamideimide resin. However, in this transparent conductive film, in addition to insufficient transparency, adhesion between layers is low and durability is not sufficient.

  Furthermore, in JP-A-2005-104141 (Patent Document 4), a cured resin layer-1 and a cured resin layer-2 having different hardnesses are sequentially laminated on at least one surface of a transparent organic polymer substrate, A transparent conductive laminated film in which a transparent conductive layer is laminated on a cured resin layer-2, wherein the cured resin layer-1 is at least selected from the group consisting of a cured resin having urethane acrylate as a monomer and synthetic rubber A transparent conductive laminated film containing 10% by weight or more of one kind is disclosed. In this document, between the curable resin layer-2 and the transparent conductive layer, the cured resin layer-3 for improving optical characteristics such as total light transmittance, and the refractive index is controlled to increase transparency. It is described that an optical interference layer is provided. Moreover, it describes that the thickness of the cured resin layer-1 is 1-10 micrometers.

  However, even this transparent conductive laminated film does not have sufficient flexibility and transparency. That is, in the cured resin layer-1, the cured resin layer-3 and the optical interference layer are necessary in order to improve both the flexibility and the transparency or to improve the optical characteristics. That is, the cured resin for forming the cured resin layer-1 has a high viscosity of the coating liquid in the coating process for forming the resin layer, and therefore, when the coating liquid is applied thickly, a coating stripe of the coating liquid is generated. If the viscosity of the coating liquid is normal, the coat stripes are naturally leveled (smoothed) during the process from application to curing and become smooth. However, in the coating solution of the cured resin layer-1 as disclosed in Patent Document 4, this leveling property is low, and when a thick coating is applied, a coating film having a smooth surface is formed. Have difficulty. And when the uneven structure by a coating | strain line | wire is formed in the surface, transparency of film itself will fall. Furthermore, in a state where the vapor deposition surface is not smooth, the keystroke durability is lowered even if vapor deposition can be performed. Moreover, even if it dilutes using a solvent, since the viscosity of a coating solution does not fall as expected, it is difficult to form a thick film with a smooth surface. In addition, the use of solvents reduces productivity and environmental performance.

Japanese Patent No. 2667680 (Claim 1, page 2, column 4, lines 22-32) JP 2004-158253 A (Claim 1) Japanese Patent No. 3972418 (Claim 1) JP 2005-104141 A (claims, paragraphs [0060] [0074])

  Accordingly, an object of the present invention is to provide a transparent conductive film that is excellent in transparency and flexibility, has excellent optical characteristics, has a good touch feeling at the time of keystroke, and can suppress cracking and damage even when repeated keystrokes. It is in providing a resistive film type touch panel provided with a conductive laminated film and this laminated film.

  Another object of the present invention is to provide a transparent conductive laminated film having excellent flexibility and productivity and a smooth surface, and a resistive film type touch panel provided with the laminated film.

  Still another object of the present invention is a transparent conductive laminated film having high productivity and excellent durability against keystroke and sliding at the edge of the display screen of the touch panel (end pressing durability and end sliding durability) and It is providing the resistive film type touch panel provided with this laminated film.

  Yet another object of the present invention is to provide a transparent conductive laminated film having high interlayer adhesion and excellent peeling durability, and a resistive film type touch panel provided with the laminated film.

  Still another object of the present invention is to provide a transparent conductive laminated film capable of increasing the thickness of a functional layer and suppressing curling, and a resistive film type touch panel provided with the laminated film.

  Still another object of the present invention is to provide a transparent conductive laminated film that can suppress the occurrence of Newton rings and that does not reduce the Newton ring prevention effect even after repeated use, and a resistive film type touch panel including the laminated film. is there.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that a specific cushion layer composed of a cured product of a polymerizable composition containing a (meth) acryl group on one surface of a transparent substrate film, By sequentially forming the functional layer and the transparent conductive layer in this order, it is excellent in transparency and flexibility, and in the resistive touch panel, it has excellent optical characteristics, and even if it is repeatedly pressed, it can suppress cracking and damage. A conductive laminated film is obtained.

  That is, the transparent conductive laminated film of the present invention is a transparent conductive laminated film in which a cushion layer, a functional layer, and a transparent conductive layer are sequentially formed in this order on one surface of a base film made of a transparent resin. The cushion layer is composed of a cured product of a polymerizable composition containing a (meth) acryl group, and the polymerizable composition has a tensile modulus of 200 MPa or less when measured by the following measurement method. It is the composition which has.

(Measurement method of tensile modulus)
The tensile modulus of a molded article having a thickness of 100 μm obtained by curing a polymerizable composition containing a (meth) acrylic group with an electron beam having an acceleration voltage of 200 kV and an irradiation dose of 50 kGy is measured.

The polymerizable composition may contain urethane (meth) acrylate. The polymerizable composition may further contain poly C _3-4 alkylene glycol di (meth) acrylate. Wherein the poly _{C 3-4} alkylene glycol di (meth) acrylate includes a poly _{C 3-4} alkylene glycol di (meth) acrylate average repeating number of oxy _{C 3-4} alkylene units is 5 to 9 moles, and urethane The ratio (weight ratio) between the (meth) acrylate and the poly C _3-4 alkylene glycol di (meth) acrylate may be about the former / the latter = 30/70 to 10/90. The thickness of the cushion layer may exceed 10 μm, and the thickness ratio of the base film to the cushion layer may be base film / cushion layer = 20/1 to 5/1. The polymerizable composition may be a composition having a tensile modulus of 1 to 100 MPa when measured by the method. Further, the polymerizable composition may be a composition that does not substantially contain a solvent. The cushion layer may have a glass transition temperature of −30 ° C. to 30 ° C., a tensile elastic modulus of 50 MPa or less, and a total light transmittance of 92% or more. In the transparent conductive laminated film of the present invention, the Martens hardness on the surface of the functional layer from which the transparent conductive layer has been peeled may be 100 N / mm ² or less, and the maximum indentation depth may be 3 μm or more. The cured product of the polymerizable composition may be a cured product by active energy rays. The functional layer may be a hard coat layer or an anti-Newton ring layer, and particularly includes one or more polymers and one or more cured curable resin precursors, and has an uneven shape on the surface. The anti-Newton ring layer comprised by the phase-separation structure may be sufficient. The transparent conductive laminated film of the present invention is a transparent electrode substrate of a resistive film type touch panel, and the transparent electrode substrate may be an upper electrode substrate on a side in contact with a finger or a pressing member.

  The transparent conductive film of the present invention is a transparent conductive laminated film in which a cushion layer, a functional layer, and a transparent conductive layer are sequentially formed in this order on one surface of a base film composed of a transparent resin, The said cushion layer may be comprised with the hardened | cured material of the polymeric composition containing a (meth) acryl group, and may have thickness larger than 10 micrometers.

  The present invention also includes a resistive film type touch panel provided with the transparent conductive laminated film as an upper electrode substrate.

  In the present invention, a specific cushion layer, a functional layer, and a transparent conductive layer made of a cured product of a polymerizable composition containing a (meth) acryl group are sequentially formed in this order on one surface of a transparent substrate film. Therefore, it is excellent in transparency and flexibility, and in the resistive film type touch panel, it has excellent optical characteristics, and even if the key is repeatedly pressed, cracking and damage can be suppressed. In particular, a cushion layer having a smooth surface and a specific tensile modulus can be formed by thick coating by a simple method without using a solvent, and both flexibility and transparency can be achieved. Furthermore, it is possible to easily produce a transparent conductive laminated film having excellent durability against keystrokes and sliding (end pressing and end sliding durability) at the end of the display screen of the touch panel. Furthermore, the adhesion between the layers is high, and the peeling durability can be improved. In addition, the thickness of the functional layer can be increased. In addition, when an anti-Newton ring layer is formed as a functional layer, the generation of Newton rings can be suppressed. In particular, when the anti-Newton ring layer is formed with a specific phase separation structure, the Newton ring prevention effect does not decrease even when used repeatedly. .

FIG. 1 is a schematic diagram showing an apparatus for measuring light transmission / scattering characteristics (angle distribution of transmitted scattered light) of a transparent conductive laminated film. FIG. 2 is a schematic sectional view showing an example of the touch panel of the present invention. FIG. 3 is a graph showing the temperature change of the linear expansion coefficient in the cured product 1 by the electron beam. FIG. 4 is a graph showing the temperature change of the linear expansion coefficient in the cured product 4 by the electron beam. FIG. 5 is a graph showing waveforms at the start of keystroke in the keystroke test of the transparent conductive laminated film obtained in Example 1. FIG. 6 is a graph showing a waveform after 1 million keystrokes in a keystroke test of the transparent conductive laminated film obtained in Example 1. FIG. 7 is a graph showing a waveform after 4.8 million keystrokes in a keystroke test of the transparent conductive laminated film obtained in Example 1. FIG. 8 is a graph showing a waveform at the start of keystroke in the keystroke test of the transparent conductive laminated film obtained in Example 2. FIG. 9 is a graph showing a waveform after 700,000 keystrokes in a keystroke test of the transparent conductive laminated film obtained in Example 2. FIG. 10 is a graph showing a waveform at the start of keystroke in the keystroke test of the transparent conductive laminated film obtained in Comparative Example 1. FIG. 11 is a graph showing a waveform after 1 million keystrokes in a keystroke test of the transparent conductive laminated film obtained in Comparative Example 1. FIG. 12 is a graph showing a waveform at the start of keystroke in the keystroke test of the transparent conductive laminated film obtained in Comparative Example 2. FIG. 13 is a graph showing a waveform after 500,000 keystrokes in a keystroke test of the transparent conductive laminated film obtained in Comparative Example 2. FIG. 14 is a graph showing a waveform after 900,000 times of keystrokes in a keystroke test of the transparent conductive laminated film obtained in Comparative Example 2.

[Transparent conductive laminated film]
In the transparent conductive laminated film of the present invention, a cushion layer, a functional layer, and a transparent conductive layer are sequentially formed in this order on one surface of a base film made of a transparent resin.

(Base film)
The base film is not particularly limited as long as it is a transparent and flexible film, and can be appropriately selected according to the use, but is usually composed of a transparent resin. The transparent resin may be a thermoplastic resin, or may be a thermosetting resin as long as it is colorless. More preferred is a thermoplastic resin. Specifically, olefin resin (polyethylene, polypropylene, amorphous polyolefin, etc.), styrene resin (polystyrene, acrylonitrile-styrene copolymer, etc.), polyester resin (polyethylene terephthalate (PET), cyclohexanedimethanol diol) PET-based copolymer (PET-G), polybutylene terephthalate (PBT), polyalkylene arylate resin such as polyethylene naphthalate (PEN), polyarylate resin, liquid crystalline polyester, etc.), polyamide resin ( Polyamide 6, polyamide 66, polyamide 12 etc.), vinyl chloride resin (polyvinyl chloride etc.), polycarbonate resin (bisphenol A type polycarbonate etc.), polyvinyl alcohol resin, cell Suesuteru resins, polyimide resins, polysulfone resins, polyphenylene ether resins, polyphenylene sulfide resins, fluorine resins can be exemplified.

  These transparent resins can be used alone or in combination of two or more. Among these plastics, at least one plastic selected from polyester resins and polycarbonate resins is preferable, and polyalkylene arylate resins such as PET and PEN are more preferable. Furthermore, a film obtained by biaxially stretching a polyalkylene arylate resin such as PET or PEN is more preferable.

  For the base film, stabilizers (antioxidants, UV absorbers, light stabilizers, heat stabilizers, etc.), crystal nucleating agents, flame retardants, flame retardant aids, fillers, plastics, as necessary. Agents, impact resistance improvers, reinforcing agents, dispersants, antistatic agents, foaming agents, antibacterial agents and the like may be added. These additives can be used alone or in combination of two or more.

  The base film may be an unstretched film or a stretched (uniaxial or biaxial) film. Further, the surface of the base film may be subjected to surface treatment such as discharge treatment such as corona discharge or glow discharge, acid treatment, and wrinkle treatment in order to improve adhesion. In the present invention, a film having an easy-adhesion layer on the surface (a film whose surface is easily adhered using a resin component) is particularly preferable. The type of the easy-adhesion layer can be selected according to the type of the base film, but in the case of the polyester film, for example, an acrylic resin, a polyester resin, a urethane resin, etc. are mentioned, but the affinity with the base film From this point, a polyester resin is preferable. As a film having an easy adhesion layer on the surface, a commercially available easy adhesion treatment film can be used.

  The thickness of the base film may be, for example, about 1 to 500 μm (for example, 10 to 500 μm), preferably 50 to 400 μm (for example, 60 to 250 μm), and more preferably about 70 to 200 μm (particularly 80 to 200 μm). .

(Cushion layer)
The cushion layer is composed of a cured product of a polymerizable composition containing a (meth) acryl group, and the cured product of the polymerizable composition has a specific tensile elastic modulus.

(1) Polymerizable composition Although the polymerizable composition should just contain the (meth) acryl group, Preferably it contains urethane (meth) acrylate as an essential component, Furthermore, the polymerizable vinyl type component etc. are included. Also good.

(A) Urethane (meth) acrylate Urethane (meth) acrylate has an active hydrogen atom in a polyisocyanate [or a urethane prepolymer having a free isocyanate group formed by a reaction between a polyisocyanate and a polyol ( It is composed of urethane (meth) acrylate obtained by reacting meth) acrylate [for example, hydroxyalkyl (meth) acrylate and the like].

  Polyisocyanates are not particularly limited as long as they have two or more isocyanate groups in the molecule. For example, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, heterocyclic polyisocyanates, and polyisocyanates thereof. Examples include isocyanate derivatives. Of these, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, polyisocyanate derivatives, and the like are often used.

Examples of the aliphatic polyisocyanate include diisocyanates [for example, C _2-16 alkanes such as tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate (TMDI). Diisocyanate, 2,6-diisocyanatomethylcaproate, lysine diisocyanate (LDI), etc.], polyisocyanates having 3 or more isocyanate groups in the molecule (for example, lysine ester triisocyanate, 1,3,6-hexamethylene) Triisocyanate, C _6-20 alkane triisocyanate such as 1,6,11-undecane triisocyanate) and the like.

  Examples of the alicyclic polyisocyanate include diisocyanates (for example, 1,4-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), 4,4′-methylenebis (cyclohexyl isocyanate), hydrogenated xylylene diisocyanate, hydrogenated bis (isocyanatophenyl). ) Methane, norbornane diisocyanate, etc.), polyisocyanates having 3 or more isocyanate groups in the molecule (for example, 1,3,5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (Isocyanatomethyl) -bicyclo [2.2.1] heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo [2.2.1] Triisocyanates such as heptane Over, such as theft), and the like.

  Examples of the aromatic polyisocyanate include diisocyanates (for example, phenylene diisocyanate, 1,5-naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), diphenylmethane diisocyanate (MDI), and tolylene diene. Isocyanate (TDI), 4,4′-toluidine diisocyanate (TODI), 4,4′-diphenyl ether diisocyanate, 1,3-bis (isocyanatophenyl) propane, etc.), poly having three or more isocyanate groups in the molecule Isocyanates (eg, triisocyanates such as 1,3,5-triisocyanatomethylbenzene, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 4,4′-diisocyanate) Enirumetan 2,2 ', like tetraisocyanates such as 5,5'-tetra isocyanate) and the like.

  Examples of the polyisocyanate derivatives include dimer, trimer, biuret, allophanate of polyisocyanate, and polyisocyanate having 2,4,6-oxadiazinetrione ring, which is a polymer of carbon dioxide and the above polyisocyanate monomer. Isocyanates, carbodiimides, uretdiones and the like.

  These polyisocyanates can be used alone or in combination of two or more. Of these polyisocyanates, aliphatic diisocyanates such as HDI, alicyclic diisocyanates such as IPDI and hydrogenated XDI, araliphatic diisocyanates such as XDI, and aromatic diisocyanates such as TDI, MDI and NDI may be used. Non-aromatic polyisocyanates such as non-aromatic polyisocyanates, for example, aliphatic diisocyanates such as HDI, alicyclic diisocyanates such as IPDI and hydrogenated XDI, or derivatives thereof when high weather resistance is required (Such as a trimer having an isocyanurate ring) may be used.

Examples of the polyols include aliphatic diol [alkanediol (ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene ether glycol, 1,3-butylene glycol, 1,5-pentanediol, neopentyl glycol, 1, C _2-10 alkane diols such as 6-hexanediol), diethylene glycol, triethylene glycol, dipropylene glycol, etc.], cycloaliphatic diols (1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc.) s, hydrogenated bisphenol such as hydrogenated bisphenol a, or an C _2-4 alkylene oxide adduct thereof), aromatic aliphatic diols and aromatic diols (xylylene glycol, bis Phenol A, bisphenol S, bisphenol such as bisphenol F, or a diol such as these _{C 2-4} alkylene oxide adduct thereof), triols (glycerol, trimethylolethane, trimethylolpropane, 1,2,6 Hexanetriol, triethanolamine and the like), tetraols (such as pentaerythritol, sorbitan or derivatives thereof), hexaols (such as dipentaerythritol), and polymer polyols.

  The polymer polyols include polyester polyols, polyether polyols, polyether ester polyols, polycarbonate polyols, polyester amide polyols, polymer polyols such as acrylic polymer polyols, and the like.

  The polyester polyol may be, for example, a reaction product of a polycarboxylic acid (or its anhydride) and a polyol, or a reaction product obtained by ring-opening addition polymerization of a lactone with respect to an initiator.

Polycarboxylic acids include dicarboxylic acids [for example, aromatic dicarboxylic acids or anhydrides thereof (terephthalic acid, isophthalic acid, phthalic anhydride, etc.), alicyclic dicarboxylic acids or anhydrides thereof (tetrahydrophthalic anhydride, het anhydride, etc. , Hymic anhydride, etc.), aliphatic dicarboxylic acid or its anhydride (succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid and other C _4-20 alkanedicarboxylic acid, maleic anhydride, fumaric acid etc. Saturated dicarboxylic acid etc.)], polyvalent carboxylic acids (for example, trimellitic acid, trimellitic anhydride, pyromellitic anhydride, etc.) or alkyl esters of these carboxylic acids. Of these polycarboxylic acids, aliphatic dicarboxylic acids or anhydrides thereof (C _6-20 alkane dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid) are preferable. These polycarboxylic acids can be used alone or in combination of two or more. Examples of the polyol include the aliphatic diol, the alicyclic diol, and the aromatic diol. These polyols can be used alone or in combination of two or more.

Examples of lactones include C such as γ-butyrolactone (GBL), γ-valerolactone, δ-valerolactone, β-methyl-δ-valerolactone, γ-caprolactone, and enanthlactone (7-hydroxyheptanoic acid lactone). _3-10 lactone etc. are mentioned. These lactones can be used alone or in combination of two or more. Of these lactones, C _4-8 lactones such as valerolactone and caprolactone are preferred.

Initiators for lactones include, for example, water, oxirane compounds (eg, C _2-6 alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc.) or copolymers [eg, polyethylene glycol (PEG) , Polypropylene glycol (PPG), polytetramethylene ether glycol (PTMG), etc.], low molecular weight polyols (ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexamethylene glycol, trimethylolpropane, glycerin, penta Erythritol, bisphenol A, etc.), compounds having an amino group (for example, ethylenediamine, hexamethylenediamine, hydrazine, xylylenediamine, isophoronediamine). Which diamine compounds, polyamine compounds such as diethylenetriamine, etc.). These initiators can be used alone or in combination of two or more.

Examples of the polyether polyol include a ring-opening polymer of the oxirane compound (for example, poly C _2-4 alkylene glycol such as polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.).

  Examples of the polyether ester polyol include a polyether which is a polymer of the dicarboxylic acid (aromatic dicarboxylic acid, alicyclic dicarboxylic acid, aliphatic dicarboxylic acid, etc.) or a dialkyl ester thereof and the polyether polyol. Examples include ester polyols.

  Examples of the polycarbonate polyol include glycols (alkane diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol; diethylene glycol, dipropylene glycol). (Poly) oxyalkylene glycols such as: 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A and other alicyclic diols; bisphenols such as bisphenol A, alkylene oxide adducts of bisphenols, etc. One or more glycols selected from aromatic diols) and carbonates (dimethyl carbonate, ethylene carbonate, diphenyl carbonate, etc.) or phosgene And the like polymers and the like.

  As the polyesteramide polyol, in the reaction of the polyester polyol (polymerization of dicarboxylic acid and diol, etc.), a terminal carboxyl group-containing polyester and a diamine (for example, an aliphatic group having an amino group such as ethylenediamine, propylenediamine, hexamethylenediamine, etc.) And polyester amide polyol having a diamine as a reaction component.

  As the acrylic polyol, a polymerizable monomer having a hydroxyl group (for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, etc.) and a hydroxyl group-free (meth) An acrylic polyol which is a polymer with an acrylic monomer (for example, (meth) acrylic acid or an ester thereof) may be used.

  These polyols can be used individually or in combination of 2 or more types. Of these polyols, polyester polyols, polyether polyols, polycarbonate polyols, and acrylic polyols are preferable from the viewpoints of flexibility and versatility. Of these, polyester polyols and polyether polyols are preferable from the viewpoint of flexibility and the like, and polyester polyols are particularly preferable from the viewpoint of excellent moisture absorption stability.

  Examples of the polyurethane prepolymer include a multimer of the polyisocyanates, a bullet-modified multimer of the polyisocyanates, an adduct of the polyisocyanates and the polyols, and an excess of the polyisocyanate with respect to the polyols. Examples thereof include polyurethane prepolymers obtained by reacting isocyanates. These prepolymers can be used alone or in combination of two or more.

  Preferred polyurethane prepolymers include, for example, multimers (trimers, pentamers, heptamers, etc.) of the polyisocyanates, burette multimers (burette-modified products) of the polyisocyanates, the polyisocyanates and polyols. Adducts with diols (triols such as glycerin and trimethylolpropane), polyurethane prepolymers of the diisocyanates and polyester polyols, polyurethane prepolymers of the diisocyanates and polyether polyols, especially the diisocyanates and polyether polyols or polyesters A polyurethane prepolymer with a polyol is preferred.

Examples of the (meth) acrylate having an active hydrogen atom include hydroxy C _2-6 alkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3- _Examples thereof include hydroxyalkoxy C _2-6 alkyl (meth) acrylate such as methoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol poly (meth) acrylate and the like.

  The number of (meth) acryloyl groups in one molecule of urethane (meth) acrylate can be selected from the range of about 1 to 10, for example, 2 to 8, preferably 2 to 6, and more preferably 2 to 4 The number is about 2 (particularly 2 to 3).

  In particular, the urethane (meth) acrylate may contain 2 to 3 functional polyester type urethane (meth) acrylate from the viewpoint of improving the flexibility of the optical sheet. Furthermore, the urethane (meth) acrylate has 2-3 functional (especially bifunctional) polyester urethane (meth) acrylate and 4-8 functional (preferably from the viewpoint of achieving both flexibility and mechanical strength of the optical sheet. A polyester type urethane (meth) acrylate of 5 to 8 possible, more preferably 6 functional) may be combined. For example, in order to adjust the balance between the flexibility and the mechanical strength of the optical sheet, the ratio (weight ratio) of the two is adjusted to a tri-functional polyester type urethane (meth) acrylate / 4- to 8-functional polyester type urethane. You may select from the range of (meth) acrylate = about 50/50-90/10.

  Further, among optical sheets, bifunctional urethane (meth) acrylates having two (meth) acryloyl groups are usually used in applications requiring high flexibility such as light guide sheets for mobile phones. The ratio of the above polyfunctional (meth) acrylate is, for example, about 50 mol% or less, preferably about 30 mol% or less, and more preferably about 10 mol% or less with respect to the entire urethane (meth) acrylate.

  The glass transition temperature (Tg) of the urethane (meth) acrylate (cured product) is sufficient if the glass transition temperature of the final polymerizable composition (cured product) is within a predetermined range, depending on the presence of other polymerization components. However, it can be selected from the range of, for example, about −100 ° C. to 100 ° C. (eg, −80 ° C. to 100 ° C.), for example, −60 ° C. to 90 ° C., preferably −40 ° C. to 80 ° C., more preferably It is about -20 ° C to 70 ° C (particularly -20 ° C to 40 ° C). Tg can be measured by the method described in the examples. Furthermore, urethane (meth) acrylates having different glass transition temperatures of cured products may be combined. For example, Tg-20 to 40 ° C. (especially 0 to 20 ° C.) urethane (meth) acrylate, and Tg-100 ° C. or more— A urethane (meth) acrylate having a temperature of less than 20 ° C. (especially −80 to −30 ° C.), the former / the latter = 90/10 to 10/90, preferably 80/20 to 20/80, more preferably 70/30 to The tensile elastic modulus of the polymerizable composition may be adjusted by combining at a ratio (weight ratio) of about 30/70.

  The urethane (meth) acrylate of the present invention comprises a polyisocyanate and a (meth) acrylate having an active hydrogen atom, usually in a ratio of an isocyanate group and an active hydrogen atom (isocyanate group / active hydrogen atom = 0.0). 8/1 to about 1.2 / 1). In addition, about the manufacturing method of these urethane (meth) acrylate, Unexamined-Japanese-Patent No. 2008-74891 etc. can be referred. The trifunctional or higher polyfunctional urethane (meth) acrylate may be a urethane (meth) acrylate obtained using polyols such as trimethylolpropane, pentaerythritol, dipentaerythritol and the like.

  The weight average molecular weight of urethane (meth) acrylate may be about 500 to 10,000, preferably 600 to 9000, and more preferably about 700 to 8,000 in terms of polystyrene in gel permeation chromatography (GPC).

(B) Polymerizable vinyl component The polymerizable vinyl component is mainly blended to control the softness (glass transition temperature) of the polymerizable composition and has an α, β-ethylenically unsaturated double bond. As long as it is a compound (curable compound), it is not particularly limited. The number of α, β-ethylenically unsaturated double bonds [particularly (meth) acryloyl group] is 1 or more per molecule (for example, 1 to 20, preferably 1 to 15, more preferably about 1 to 10). It may be.

  The vinyl component may be a monomer or an oligomer (or prepolymer), or a combination of a monomer and an oligomer.

  Examples of vinyl monomers include monofunctional vinyl monomers [monofunctional (meth) acrylate (or mono (meth) acrylate), etc.], bifunctional vinyl monomers [bifunctional (meth) acrylate (or di (meth) acrylate) A trifunctional or higher functional vinyl monomer [a trifunctional or higher functional polyfunctional (meth) acrylate (or poly (meth) acrylate)]].

Monofunctional vinyl monomers include, for example, (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl ( (Meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, C _1-24 alkyl (meth) acrylates such as stearyl (meth) acrylate; cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate; dicyclopentanyl (meth) acrylate, dicyclo Bridged cyclic (meth) acrylates such as pentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate; phenyl (meta ) Acrylate, aryl (meth) acrylates such as nonylphenyl (meth) acrylate; aralkyl (meth) acrylates such as benzyl (meth) acrylate; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate hydroxy _{C 2-10} alkyl (meth) acrylate or _{C 2-10} alkanediol mono (meth) acrylate and the like; trifluoroethyl (meth) acrylate, Tetorafuru Ropuropiru (meth) acrylate, fluoroalkyl C _1-10 alkyl (meth) acrylates such as hexafluoroisopropyl (meth) acrylate; alkoxyalkyl such as methoxyethyl (meth) acrylate (meth) acrylate; phenoxyethyl (meth) acrylate, phenoxypropyl Aryloxyalkyl (meth) acrylates such as (meth) acrylate; aryloxy (poly) alkoxyalkyl (meta) such as phenyl carbitol (meth) acrylate, nonylphenyl carbitol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate ) Acrylate; polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate; Alkane polyol mono (meth) acrylate such as mono (meth) acrylate; amino group such as 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-t-butylaminoethyl (meth) acrylate, or Examples include (meth) acrylate having a substituted amino group; glycidyl (meth) acrylate and the like.

Examples of the bifunctional vinyl monomer include allyl (meth) acrylate; ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-propanediol di (meth) acrylate, and 1,4-butanediol. Alkanediol di (meth) acrylates such as di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate; alkane polyol di (meth) such as glycerin di (meth) acrylate Acrylate: Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol Polyalkylene glycol di (meth) acrylates such as di (meth) acrylate; 2,2-bis (4- (meth) acryloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxydiethoxyphenyl) ) Di (meth) acrylates of C _2-4 alkylene oxide adducts of bisphenols (bisphenol A, S, etc.) such as propane and 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane; Examples include di (meth) acrylates of acid-modified alkane polyols such as pentaerythritol; bridged di (meth) acrylates such as tricyclodecane dimethanol di (meth) acrylate and adamantane di (meth) acrylate.

Examples of the polyfunctional vinyl monomer include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. , Tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkane polyol poly (meth) acrylate such as dipentaerythritol hexa (meth) acrylate; C _2-4 alkylene oxide adduct of the alkane polyol Tri (meth) acrylate; Tri (meth) acrylate having triazine ring such as tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate Can be exemplified.

  These monomers can be used alone or in combination of two or more.

  Examples of the vinyl-based oligomer include polyester (meth) acrylate [for example, polyester (meth) acrylate produced by reaction of polyvalent carboxylic acid, polyol, (meth) acrylic acid and / or hydroxyalkyl (meth) acrylate, etc.]; alkyd Resin; Epoxy (meth) acrylate [for example, epoxy compound having a plurality of epoxy groups (polyhydric alcohol type, polyvalent carboxylic acid type, bisphenol type such as bisphenol A, F, S, or novolac type epoxy resin) ( (Meth) acrylic acid ring-opened addition of epoxy (meth) acrylate, etc.]; polyacrylic (meth) acrylate [for example, (meth) acrylic to a copolymer of (meth) acrylic monomer and glycidyl (meth) acrylate Polyamides with ring-opening addition of acid to epoxy group Such as Lil (meth) acrylate]; polyether (meth) acrylate; polybutadiene (meth) acrylate; melamine (meth) acrylate; Silicone (meth) acrylate; polyacetal (meth) acrylate can be exemplified. These oligomers can be used alone or in combination of two or more.

Among these vinyl components, bifunctional vinyl monomers such as (poly) C _2-6 alkylene glycol di (meth) acrylate are widely used. Furthermore, among the (poly) C _2-6 alkylene glycol di (meth) acrylates, poly C _2-6 alkylene glycol di (meth) acrylate is preferable from the viewpoint of flexibility and the like, in addition to flexibility, In particular, poly C _3-4 alkylene glycol di (meth) acrylates such as polypropylene glycol di (meth) acrylate are particularly preferable. The average number of repeating oxy C _3-4 alkylene units can be selected from a range of about 1.2 to 30 mol per molecule, for example, 1.5 to 20 mol, preferably 2 to 15 mol, more preferably 3 About 10 mol (especially 5-9 mol) may be sufficient.

The ratio (weight ratio) of urethane (meth) acrylate and vinyl-based polymerization component (for example, poly C _3-4 alkylene glycol di (meth) acrylate) depends on the desired softness (glass transition temperature) and the like. / The latter = can be selected from the range of about 100/0 to 1/99, for example, the former / the latter = 90/10 to 2/98, preferably 70/30 to 3/97, more preferably 50/50 to 5 / It may be about 95 (particularly 30/70 to 10/90).

Furthermore, even when using a 2-functional (especially bifunctional) polyester urethane (meth) acrylate, the mechanical strength may be insufficient depending on the molecular structure of the urethane (meth) acrylate. the poly _{C 3-4} alkylene glycol di (meth) acrylates [in particular, poly _{C 3-4} alkylene glycol di average repeating number of oxy _{C 3-4} alkylene units is 5 to 9 mol (meth) acrylate] and By combining, the mechanical strength can be improved while maintaining flexibility.

(C) Polymerization initiator The polymerization composition may contain a polymerization initiator. A polymerization initiator is required except when cured by EB. The polymerization initiator may be a thermal polymerization initiator (thermal radical generator such as a peroxide such as benzoyl peroxide) or a photopolymerization initiator (photo radical generator). A preferred polymerization initiator is a photopolymerization initiator. Examples of the photopolymerization initiator include benzoins (benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether), phenyl ketones [for example, acetophenones (for example, acetophenone, 2-hydroxy 2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, etc.), 2-hydroxy-2 -Alkyl phenyl ketones such as methylpropiophenone; cycloalkyl phenyl ketones such as 1-hydroxycyclohexyl phenyl ketone], aminoacetophenones {2-methyl-1- [4- (methylthio) phene Lu] -2-morpholinoaminopropanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1}, anthraquinones (anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone) , 2-t-butylanthraquinone, 1-chloroanthraquinone, etc.), thioxanthones (2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, etc.), ketals (acetophenone) Dimethyl ketal, benzyl dimethyl ketal, etc.), benzophenones (benzophenone, etc.), xanthones, phosphine oxides (eg 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc.) It can be shown. These photopolymerization initiators can be used alone or in combination of two or more.

  The ratio of the polymerization initiator is 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, based on 100 parts by weight of the polymerization component (the total of urethane (meth) acrylate and polymerizable vinyl component). More preferably, it may be about 1 to 10 parts by weight (particularly 3 to 8 parts by weight).

  In addition, you may combine a photoinitiator with a photosensitizer. Examples of the photosensitizer include conventional components such as tertiary amines [for example, trialkylamine, trialkanolamine (such as triethanolamine), ethyl N, N-dimethylaminobenzoate, N, N-dimethyl. Dialkylaminobenzoic acid alkyl esters such as amyl aminobenzoic acid, bis (dialkylamino) benzophenones such as 4,4-bis (dimethylamino) benzophenone (Michler's ketone), 4,4′-diethylaminobenzophenone], triphenylphosphine, etc. Examples include phosphines, toluidines such as N, N-dimethyltoluidine, anthracene such as 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene. It is done. The photosensitizers may be used alone or in combination of two or more.

  The ratio of the photosensitizer is, for example, about 0.1 to 100 parts by weight, preferably 0.5 to 80 parts by weight, and more preferably about 1 to 50 parts by weight with respect to 100 parts by weight of the photopolymerization initiator. There may be.

  It is preferable that the polymerization initiator (particularly the photopolymerization initiator and photosensitizer) is not substantially contained when the polymerizable composition is cured by irradiation with an electron beam. When it does not contain a polymerization initiator, weather resistance, in particular, difficult yellowing for long-term use is improved.

  In addition to the polymerization initiator, the polymerizable composition is a conventional additive such as an antioxidant, a stabilizer such as a heat stabilizer, a plasticizer, and an antistatic agent, as long as flexibility and transparency are not impaired. Further, it may contain a flame retardant, an ultraviolet absorber and the like.

  Furthermore, the polymerizable composition may be an organic solvent such as ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic. Hydrocarbons (such as cyclohexane), aromatic hydrocarbons (such as benzene), halogenated carbons (such as dichloromethane and dichloroethane), esters (such as methyl acetate and ethyl acetate), water, alcohols (ethanol, isopropanol, butanol) , Cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, amides (dimethylformamide, dimethylacetamide, etc.) and the like. Furthermore, in this invention, since the resin component which has a specific viscoelasticity is used as a polymeric composition, even if it does not contain a solvent, it is excellent in applicability | paintability. Therefore, the polymerizable composition may not substantially contain a solvent. Moreover, even if it does not contain a solvent substantially, a viscosity is low and thick coating is possible.

  It is preferable that the polymerizable composition has a (meth) acryl group as an essential component, and preferably includes the urethane (meth) acrylate illustrated above, and further includes the polymerizable vinyl-based component and polymerization initiator illustrated above. The composition is not limited, but a cured product (molded product) having a thickness of 100 μm cured by an electron beam with an acceleration voltage of 200 kV and an irradiation dose of 50 kGy is 200 MPa by a method (25 ° C.) according to JIS K7113. It is necessary to prepare the composition having the following tensile modulus. When such a polymerizable composition is used, the keystroke durability in a touch panel or the like can be improved. Moreover, since the viscosity of the coating liquid is low and a thick film with a smooth surface can be formed by a simple method, both transparency and flexibility can be achieved. That is, such a polymerizable composition has a characteristic that achieves both high transparency and flexibility. However, even if a cushion layer having a thickness larger than 10 μm (particularly a thickness of 12 μm or more) is formed, it results from application. Occurrence of thickness unevenness is suppressed, and the above characteristics can be effectively expressed.

  Specifically, the tensile modulus may be about 0.1 to 150 MPa, preferably 1 to 100 MPa, more preferably 1 to 80 MPa (particularly 1 to 50 MPa), and even more preferably about 1 to 35 MPa. There may be. The polymerizable composition having such a tensile elastic modulus may be prepared by combining, for example, a plurality of types of urethane (meth) acrylates (for example, different glass transition temperatures of curing components), and urethane (meth) acrylates. And a polymerizable vinyl component may be prepared in combination. In particular, by mixing a plurality of types of urethane (meth) acrylates, the viscosity of the coating solution can be relatively lowered and adjusted so that thick coating is possible. The tensile elastic modulus of the cured product having a thickness of 100 μm cured by an electron beam with an acceleration voltage of 200 kV and an irradiation dose of 50 kGy is a characteristic for defining the type of the polymerizable composition used in the present invention. There is no direct relationship with the tensile modulus of the cushion layer as an object. Further, as a method for measuring the tensile elastic modulus, specifically, the method described in Examples described later can be used.

(2) Cured product of the polymerizable composition (cushion layer)
The glass transition temperature (Tg) of the cushion layer obtained by curing the polymerizable composition is -30 ° C to 30 ° C, preferably -30 ° C to 20 ° C (-30 ° C to 10 ° C), and more preferably. It is about -20 degreeC-10 degreeC (especially -10 degreeC-5 degreeC). When the glass transition temperature is on the lower temperature side than the vicinity of 20 ° C., that is, on the lower temperature side than the temperature to be used, the flexibility becomes softer and the physical properties are stabilized in the operating temperature range.

  The cushion layer has high transparency, and the total light transmittance measured according to JIS K7361-1 is, for example, 80% or more (for example, 80 to 100%), preferably 90% or more (for example, 90 to 99%), more preferably 92% or more (for example, 92 to 98%), particularly about 93 to 97%. The haze measured according to JIS K7361-1 is, for example, 5% or less (for example, 0.1 to 5%), preferably 3% or less (for example, 0.2 to 3%), and more preferably 2. It is about 5% or less (for example, 0.5 to 2.5%).

  The cushion layer has little color, and the b * value measured in the transmission mode according to JIS K7105 is, for example, 1 or less (for example, 0.01 to 1), preferably 0.8 or less (for example, 0.03 to 0.03). 0.8), more preferably about 0.5 or less (for example, 0.1 to 0.5). Furthermore, the cushion layer is also excellent in weather resistance, and yellowing is suppressed even when irradiated with ultraviolet rays or the like under severe conditions for a long period of time. For example, the b * value after performing an exposure test based on JIS K7350-2 using a weather meter (Suga Test Instruments Co., Ltd., Super Xenon Weather Meter, “SX2-75”) is, for example, 3 Below (for example, 0.05 to 3), preferably 2 or less (for example, 0.1 to 2), more preferably about 1.5 or less (for example, 0.3 to 1.5).

  Furthermore, since the cushion layer is composed of a cured resin, when the base film is a plastic such as polyethylene terephthalate due to the presence of the cushion layer, low molecular components such as oligomers are precipitated by heat from the inside of the base film. This can also be suppressed.

  The thickness of the cushion layer is, for example, preferably greater than 10 μm (especially a thickness of 12 μm or more) from the viewpoint of flexibility, for example, 11-50 μm, preferably 12-40 μm, more preferably 15-30 μm (especially 15-30 μm). 25 μm). In particular, in the present invention, a coating film having a smooth surface and 12 μm or more can be formed without using a solvent.

  Furthermore, the thickness ratio between the base film and the cushion layer is, for example, base film / cushion layer = 20/1 to 5/1, preferably 18/1 to 6/1, more preferably 15/1 to 7 /. 1 (especially 12/1 to 8/1). In the present invention, the thickness of the cushion layer is moderately thick and has such a thickness ratio with respect to the base film, and is formed close to the transparent conductive layer by forming the cushion layer by coating as described later. A cushion layer acts effectively and can suppress a crack and damage of a transparent conductive layer.

(Functional layer)
Examples of the functional layer (first functional layer) include conventional functional layers such as a hard coat layer, an anti-Newton ring layer, a light scattering layer, an antireflection layer, and a low refractive index layer. Among these, a hard coat layer, an anti-Newton ring layer, etc. are widely used. The hard coat layer is not particularly limited as long as it is a transparent and highly scratch-resistant material, but is preferably a curable resin, for example, urethane (meth) acrylate and / or polymerizable vinyl-based component exemplified in the cushion layer. From the point of having the transparency, flexibility (flexibility), and scratch resistance required for the touch panel, among the cured product of the composition containing, can be used a cured product having a glass transition temperature higher than the cushion layer, etc. A polymerizable composition containing urethane (meth) acrylate is particularly preferred.

  Furthermore, in the present invention, it is particularly preferable to form an anti-Newton ring layer as the functional layer from the viewpoint that the visibility of the touch panel can be improved. The anti-Newton ring layer (Newton ring prevention layer) is not particularly limited as long as it is transparent and has anti-Newton ring properties, but a layer having an uneven structure on the surface is preferable. In the present invention, by forming the anti-Newton ring layer, it is possible to suppress the generation of Newton rings in the display unit of the touch panel, and therefore, this is particularly effective in a large screen touch panel. As an anti-Newton ring layer having a concavo-convex structure on the surface, for example, a layer in which a concavo-convex structure is formed by phase separation of a plurality of polymer components (or precursors thereof) (an anti-Newton ring layer using phase separation), a polymer component ( Alternatively, a layer in which a concavo-convex structure is formed by blending particles in a precursor thereof (anti-Newton ring layer in which particles are blended), a layer in which a concavo-convex structure is formed using a template, and the like can be given. Of these, a layer using phase separation and a layer containing particles are preferable from the viewpoint that high antiglare properties can be easily expressed.

(1) Anti-Newton ring layer using phase separation The layer using phase separation includes one or more polymers and one or more cured curable resin precursors, and has a concavo-convex shape (concavo-convex structure) on the surface. ). The phase separation structure of the anti-Newton ring layer is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase. That is, using a resin composition composed of a polymer, a curable resin precursor, and a solvent, in the process of removing the solvent by drying or the like from the liquid phase of this resin composition (or a uniform solution or coating layer thereof), Along with the concentration, phase separation due to spinodal decomposition occurs, and a phase separation structure having a fine interphase distance and a relatively regular phase can be formed. More specifically, the wet spinodal decomposition is usually performed by coating a base film with a mixed solution or a resin composition (homogeneous solution) containing one or more polymers, one or more curable resin precursors, and a solvent. And it can carry out by evaporating a solvent from the formed application layer. Such a concavo-convex structure with a phase separation structure is finer than a concavo-convex structure with fine particles, and a concavo-convex structure can be formed without using hard fine particles. Furthermore, since this uneven structure has a regular, smooth (or gentle) surface structure in addition to a fine structure, the transparent conductive layer is damaged or deteriorated even if it is rolled up and wound. Can be suppressed.

(A) Polymer component As the polymer component, a thermoplastic resin is usually used. Thermoplastic resins include styrene resins, (meth) acrylic resins, organic acid vinyl ester resins, vinyl ether resins, halogen-containing resins, olefin resins (including alicyclic olefin resins), polycarbonate resins, Polyester resin, polyamide resin, thermoplastic polyurethane resin, polysulfone resin (polyethersulfone, polysulfone, etc.), polyphenylene ether resin (2,6-xylenol polymer, etc.), cellulose derivatives (cellulose esters, cellulose carbamate) , Cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubbers or elastomers (diene rubbers such as polybutadiene, polyisoprene, styrene-butadiene copolymers) Acrylonitrile - butadiene copolymer, acrylic rubber, urethane rubber, silicone rubber, etc.), and others. These thermoplastic resins can be used alone or in combination of two or more.

  Among these thermoplastic resins, styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins Cellulose derivatives, silicone resins, rubbers or elastomers are preferred. Further, as the thermoplastic resin, a resin that is amorphous and is soluble in an organic solvent (particularly, a common solvent capable of dissolving a plurality of polymers and curable compounds) is used. In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferable.

  Styrene resins include styrene monomers alone or copolymers (polystyrene, styrene-α-methylstyrene copolymer, styrene-vinyltoluene copolymer, etc.), styrene monomers and other polymerizable properties. Copolymers with monomers [(meth) acrylic monomers, maleic anhydride, maleimide monomers, dienes, etc.] are included. Examples of the styrene-based copolymer include a styrene-acrylonitrile copolymer (AS resin), a copolymer of styrene and a (meth) acrylic monomer [styrene-methyl methacrylate copolymer, styrene-methacrylic acid. Methyl- (meth) acrylic acid ester copolymer, styrene-methyl methacrylate- (meth) acrylic acid copolymer, etc.], styrene-maleic anhydride copolymer and the like. Preferred styrenic resins include polystyrene, copolymers of styrene and (meth) acrylic monomers [copolymers based on styrene and methyl methacrylate such as styrene-methyl methacrylate copolymer], AS resin, styrene-butadiene copolymer and the like are included.

  As the (meth) acrylic resin, a (meth) acrylic monomer alone or a copolymer, a copolymer of a (meth) acrylic monomer and a copolymerizable monomer, or the like can be used. Examples of the (meth) acrylic monomer include a monofunctional vinyl monomer exemplified as the polymerizable vinyl component (2) in the cushion layer. Examples of the copolymerizable monomer include the styrene monomer, vinyl ester monomer, maleic anhydride, maleic acid, and fumaric acid. These monomers can be used alone or in combination of two or more.

Examples of the (meth) acrylic resin include poly (meth) acrylic acid esters such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer Polymer, methyl methacrylate-acrylic acid ester- (meth) acrylic acid copolymer, (meth) acrylic acid ester-styrene copolymer (MS resin, etc.), (meth) acrylic acid-methyl (meth) acrylate- ( And meth) acrylic acid isobornyl. Preferable (meth) acrylic resins include poly (meth) acrylic acid C _1-6 alkyl such as poly (meth) methyl acrylate, particularly methyl methacrylate as a main component (50 to 100% by weight, preferably 70 to 100%). And a methyl methacrylate-based resin. Further, the (meth) acrylic resin may be a silicone-containing (meth) acrylic resin.

  As the alicyclic olefin-based resin, a cyclic olefin (norbornene, dicyclopentadiene, etc.) alone or a copolymer (for example, a polymer having an alicyclic hydrocarbon group such as sterically rigid tricyclodecane, etc.) And a copolymer of the cyclic olefin and a copolymerizable monomer (such as an ethylene-norbornene copolymer and a propylene-norbornene copolymer). The alicyclic olefin-based resin is available, for example, under the trade name “TOPAS”, the trade name “ARTON”, the trade name “ZEONEX”, and the like.

The polyester resin may be a homopolyester such as poly _C2-4 alkylene terephthalate such as polyethylene terephthalate or polybutylene terephthalate or poly _C2-4 alkylene naphthalate, but terephthalic acid from the viewpoint of solvent solubility. An aromatic copolyester using an aromatic dicarboxylic acid such as C _2-4 alkylene arylate unit (C _2-4 alkylene terephthalate and / or C _2-4 alkylene naphthalate unit) as a main component (for example, 50% by weight or more) Etc.] are preferred. The copolyesters, poly _{C 2-4} among constituent units of alkylene _{arylate, C 2-4} part of the alkylene glycol, polyoxy _{C 2-4} alkylene _{glycols, C 5-10} alkylene glycol, alicyclic diols (cyclohexane Substituted with diol having an aromatic ring (9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, bisphenol A, bisphenol A-alkylene oxide adduct, etc.), etc. Copolyesters and copolyesters in which a part of the aromatic dicarboxylic acid is substituted with an asymmetric aromatic dicarboxylic acid such as phthalic acid or isophthalic acid or an aliphatic C _6-12 dicarboxylic acid such as adipic acid are included. Polyester resins also include aliphatic polyesters using aliphatic dicarboxylic acids such as adipic acid, and lactones such as ε-caprolactone, or copolymers. A preferred polyester resin is usually amorphous, such as an amorphous copolyester (for example, C _2-4 alkylene arylate copolyester).

Among cellulose derivatives, cellulose esters include, for example, aliphatic organic acid esters (cellulose acetate such as cellulose diacetate and cellulose triacetate; cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate). C _1-6 organic acid esters, etc.), aromatic organic acid esters (C _7-12 aromatic carboxylic acid esters such as cellulose phthalate and cellulose benzoate), inorganic acid esters (eg, cellulose phosphate, cellulose sulfate, etc.) It may be a mixed acid ester such as acetic acid / cellulose nitrate ester. Cellulose derivatives include cellulose carbamates (eg, cellulose phenyl carbamate), cellulose ethers (eg, cyanoethyl cellulose; hydroxy C _2-4 alkyl cellulose such as hydroxyethyl cellulose, hydroxypropyl cellulose; C _{1- 1} such as methyl cellulose, ethyl cellulose, etc. ₆ alkylcellulose; carboxymethylcellulose or a salt thereof, benzylcellulose, acetylalkylcellulose, etc.).

As the polymer component, a polymer having a functional group involved in the curing reaction (or a functional group capable of reacting with the curable compound) can also be used. The polymer may have a functional group in the main chain or a side chain. The functional group may be introduced into the main chain by copolymerization or cocondensation, but is usually introduced into the side chain. Such functional groups include condensable groups and reactive groups (for example, hydroxyl groups, acid anhydride groups, carboxyl groups, amino groups or imino groups, epoxy groups, glycidyl groups, isocyanate groups, etc.), polymerizable groups ( For example, C _2-6 alkenyl groups such as vinyl, propenyl, isopropenyl, butenyl and allyl, C _2-6 alkynyl groups such as ethynyl, propynyl and butynyl, C _2-6 alkenylidene groups such as vinylidene, or their polymerizability And a group having a group (such as a (meth) acryloyl group). Of these functional groups, a polymerizable group is preferable.

  As a method for introducing a polymerizable group into a side chain, for example, a thermoplastic resin having a functional group such as a reactive group or a condensable group is reacted with a polymerizable compound having a reactive group with the functional group. The method can be used.

  Examples of the thermoplastic resin having a functional group include a thermoplastic resin having a carboxyl group or an acid anhydride group thereof, a thermoplastic resin having a hydroxyl group, a thermoplastic resin having an amino group, and a thermoplastic resin having an epoxy group. it can. Moreover, the resin which introduce | transduced the said functional group into the thermoplastic resin which does not have a functional group by copolymerization or graft polymerization may be sufficient.

  As the polymerizable compound, in the case of a thermoplastic resin having a carboxyl group or its acid anhydride group, a polymerizable compound having an epoxy group, a hydroxyl group, an amino group, an isocyanate group, or the like can be used. In the case of a thermoplastic resin having a hydroxyl group, a polymerizable compound having a carboxyl group or its acid anhydride group or an isocyanate group can be used. In the case of a thermoplastic resin having an amino group, a polymerizable compound having a carboxyl group or its acid anhydride group, an epoxy group, an isocyanate group, and the like can be mentioned. In the case of a thermoplastic resin having an epoxy group, a polymerizable compound having a carboxyl group or an acid anhydride group or an amino group thereof can be used.

Among the polymerizable compounds, examples of the polymerizable compound having an epoxy group include epoxycyclo C _5-8 alkenyl (meth) acrylate such as epoxycyclohexenyl (meth) acrylate, glycidyl (meth) acrylate, allyl glycidyl ether, and the like. Can be illustrated. Examples of the compound having a hydroxyl group include hydroxy C _1-4 alkyl (meth) acrylate such as hydroxypropyl (meth) acrylate, C _2-6 alkylene glycol (meth) acrylate such as ethylene glycol mono (meth) acrylate, and the like. It can be illustrated. Examples of the polymerizable compound having an amino group include amino _C1-4 alkyl (meth) acrylate such as aminoethyl (meth) acrylate, C _3-6 alkenylamine such as allylamine, 4-aminostyrene, diaminostyrene, and the like. Examples include aminostyrenes. Examples of the polymerizable compound having an isocyanate group include (poly) urethane (meth) acrylate and vinyl isocyanate. Examples of the polymerizable compound having a carboxyl group or an acid anhydride group thereof include unsaturated carboxylic acids such as (meth) acrylic acid and maleic anhydride, or anhydrides thereof.

  As a typical example, a thermoplastic resin having a carboxyl group or its acid anhydride group and an epoxy group-containing compound, particularly a (meth) acrylic resin ((meth) acrylic acid- (meth) acrylic acid ester copolymer, etc.) ) And an epoxy group-containing (meth) acrylate (such as epoxycycloalkenyl (meth) acrylate and glycidyl (meth) acrylate). Specifically, a polymer in which a polymerizable unsaturated group is introduced into a part of the carboxyl group of the (meth) acrylic resin, for example, one of the carboxyl groups of the (meth) acrylic acid- (meth) acrylic acid ester copolymer. The (meth) acrylic polymer (Cyclomer P, manufactured by Daicel Chemical Industries, Ltd.) in which the epoxy group of 3,4-epoxycyclohexenylmethyl acrylate was reacted to the part to introduce a photopolymerizable unsaturated group into the side chain ) Etc. can be used.

  The introduction amount of the functional group (particularly polymerizable group) involved in the curing reaction for the thermoplastic resin is 0.001 to 10 mol, preferably 0.01 to 5 mol, more preferably 0 with respect to 1 kg of the thermoplastic resin. About 0.02 to 3 moles.

These polymers can be used in appropriate combination. That is, the polymer may be composed of a plurality of polymers. The plurality of polymers may be phase separable by liquid phase spinodal decomposition. The plurality of polymers may be incompatible with each other. When combining a plurality of polymers, the combination of the first polymer and the second polymer is not particularly limited, but suitable as a plurality of polymers that are incompatible with each other near the processing temperature, for example, two polymers that are incompatible with each other Can be used in combination. For example, when the first polymer is a styrene resin, the second polymer may be a cellulose derivative, a (meth) acrylic resin, an alicyclic olefin resin, a polycarbonate resin, a polyester resin, or the like. . For example, when the first polymer is a cellulose derivative, the second polymer is a styrene resin, a (meth) acrylic resin (particularly, a (meth) acrylic resin having a polymerizable group), an alicyclic type. It may be an olefin resin, a polycarbonate resin, a polyester resin, or the like. In a combination of a plurality of resins, at least cellulose esters (for example, cellulose C _2-4 alkyl carboxylic acid esters such as cellulose diacetate, cellulose triacetate, cellulose acetate propionate, and cellulose acetate butyrate) may be used.

  Note that the phase separation structure (raised surface irregularities) generated by spinodal decomposition is finally cured by active energy rays (ultraviolet rays, electron beams, etc.) or heat to form a cured resin.

  From the viewpoint of durability after curing (abrasion resistance) and the like, at least one of a plurality of polymers, for example, one of the polymers incompatible with each other (the first polymer and the second polymer) When both are combined, it is particularly preferable that both polymers) have a functional group capable of reacting with the curable resin precursor in the side chain.

  The ratio (weight ratio) between the first polymer and the second polymer is, for example, the former / the latter = 1/99 to 99/1, preferably 5/95 to 95/5, more preferably 10/90 to 90. Can be selected from the range of about / 10, and is usually about 20/80 to 80/20, particularly about 30/70 to 70/30.

  In addition, as a polymer for forming a phase-separated structure, the said thermoplastic resin and another polymer other than the said two incompatible polymers may be contained.

  The glass transition temperature of the polymer may be, for example, -100 to 250 ° C, preferably 0 to 200 ° C, more preferably about 50 to 180 ° C (particularly about 100 to 170 ° C). The weight average molecular weight of a polymer can be selected from the range of about 1,000,000 or less, preferably about 1,000 to 500,000, for example.

(B) Curable resin precursor A curable resin precursor is a compound having a functional group that reacts with heat or active energy rays (such as ultraviolet rays or electron beams) and is cured or cross-linked with heat or active energy rays. Various curable compounds capable of forming resins (particularly cured or crosslinked resins), such as thermosetting compounds or resins [low molecular weight compounds having epoxy groups, polymerizable groups, isocyanate groups, alkoxysilyl groups, silanol groups, etc. (For example, epoxy resins, unsaturated polyester resins, urethane resins, silicone resins, etc.), photocurable compounds curable with active energy rays (such as ultraviolet rays) (UV curing of photocurable monomers, oligomers, etc.) The photocurable compound may be an EB (electron beam) curable compound. Note that a photocurable compound such as a photocurable monomer, an oligomer, or a photocurable resin that may have a low molecular weight may be simply referred to as a “photocurable resin”.

  Examples of the photocurable compound include monomers and oligomers (or resins, particularly low molecular weight resins). The monomer can be classified into, for example, a monofunctional monomer having one polymerizable group and a polyfunctional monomer having at least two polymerizable groups.

  Examples of the monofunctional monomer include monofunctional vinyl monomers exemplified as the polymerizable vinyl component (2) in the cushion layer, and vinyl monomers such as vinyl pyrrolidone. The polyfunctional monomer includes a polyfunctional monomer having about 2 to 8 polymerizable groups, and examples of the bifunctional monomer include a polymerizable vinyl-based component (2) in the cushion layer. Examples thereof include the bifunctional vinyl monomers exemplified. Examples of the 3-8 functional monomer include polyfunctional vinyl monomers exemplified as the polymerizable vinyl component (2) in the cushion layer.

  Examples of the oligomer or resin include urethane (meth) acrylate in the cushion layer, vinyl oligomer exemplified as the polymerizable vinyl component (2), and the like. These (meth) acrylate oligomers or resins may contain a copolymerizable monomer exemplified in the section of (meth) acrylic resin in the polymer component. These photocurable compounds can be used alone or in combination of two or more.

  Furthermore, the curable resin precursor may contain fluorine atoms and inorganic particles from the viewpoint that the haze value can be lowered and the strength of the layer can be improved, and transparency and strength are improved. Precursors containing fluorine atoms (fluorine-containing curable compounds) include fluorides of the monomers and oligomers, such as fluoroalkyl (meth) acrylates [for example, perfluorooctylethyl (meth) acrylate and trifluoroethyl (Meth) acrylate, etc.], fluoro (poly) alkylene glycol di (meth) acrylate [eg, fluoroethylene glycol di (meth) acrylate, fluoropropylene glycol di (meth) acrylate, etc.], fluorine-containing epoxy resin, fluorine-containing urethane Resin etc. are mentioned. Examples of the precursor containing inorganic particles include inorganic particles having a polymerizable group on the surface (for example, silica particles whose surface is modified with a silane coupling agent having a polymerizable group). As nano-sized silica particles having a polymerizable group on the surface, for example, a polyfunctional hybrid UV curing agent (Z7501) is commercially available from JSR Corporation.

  Preferred curable resin precursors are photocurable compounds that can be cured in a short time, for example, ultraviolet curable compounds (monomers, oligomers, resins that may be low molecular weight, etc.), and EB curable compounds. In particular, a practically advantageous resin precursor is an ultraviolet curable resin. Furthermore, in order to improve durability against repeated use (keystroke), the photocurable resin is a bifunctional or higher (preferably 2 to 10 functional, more preferably about 3 to 8 functional) photocurable compound, It is preferable to contain polyfunctional (meth) acrylates, for example, trifunctional or higher (particularly 4 to 8 functional) (meth) acrylates.

  Further, in the present invention, the curable resin precursor may be a combination of 5 to 7 functional (meth) acrylate and 3 to 4 functional (meth) acrylate. The ratio (weight ratio) of both is, for example, the former / the latter = 100/0 to 10/90, preferably 99/1 to 30/70, more preferably 90/10 to 50/50 (particularly 80/20 to 40). / 60) grade.

  In addition, when combining a polyfunctional (meth) acrylate and the fluorine-containing curable compound (particularly, a monomer having a fluorine atom such as (meth) acrylate containing a fluorinated alkyl chain and a (meth) acryloyl group), fluorine The ratio of the containing curable compound is, for example, 0.01 to 5 parts by weight, preferably 0.05 to 1 part by weight, and more preferably 0.1 to 0.1 part by weight with respect to 100 parts by weight of the polyfunctional (meth) acrylate. About 5 parts by weight.

  The molecular weight of the curable resin precursor is about 5000 or less, preferably about 2000 or less, more preferably about 1000 or less in consideration of compatibility with the polymer.

  The curable resin precursor may contain a curing agent depending on the type. For example, the thermosetting resin may contain a curing agent such as amines and polyvalent carboxylic acids, and the photocurable resin may contain a photopolymerization initiator. Examples of the photopolymerization initiator include conventional components such as acetophenones or propiophenones, benzyls, benzoins, benzophenones, thioxanthones, acylphosphine oxides, and the like. The content of the curing agent such as a photocuring agent is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight (100 parts by weight based on 100 parts by weight of the curable resin precursor. In particular, it is about 1 to 5 parts by weight, and may be about 3 to 8 parts by weight.

  Furthermore, the curable resin precursor may contain a curing accelerator. For example, the photocurable resin may contain a photocuring accelerator, for example, a tertiary amine (such as a dialkylaminobenzoic acid ester), a phosphine photopolymerization accelerator, and the like.

  Of the at least one polymer and the at least one curable resin precursor, at least two components are used in combination that phase separate from each other near the processing temperature. Although it does not specifically limit as a combination which carries out phase separation, Usually, it is a combination of several polymers, and a combination of a polymer and a curable resin precursor, and especially the combination of several polymers is preferable. When the compatibility between the two to be phase-separated is high, both do not effectively phase-separate during the drying process for evaporating the solvent, and the function as an anti-Newton ring layer is lowered.

  The polymer and the curable resin precursor (or curable resin) may be compatible with each other or incompatible with each other. When the polymer and the curable resin precursor are incompatible and phase-separated, a plurality of polymers may be used as the polymer. When a plurality of polymers are used, it is sufficient that at least one polymer is incompatible with the resin precursor (or cured resin), and other polymers may be compatible with the resin precursor.

  When the polymer is composed of a plurality of incompatible polymers and phase-separated, the curable resin precursor is a combination in which at least one of the incompatible polymers is compatible with each other near the processing temperature. Used in. That is, when a plurality of polymers that are incompatible with each other are composed of, for example, a first polymer and a second polymer, the curable resin precursor is compatible with at least either the first polymer or the second polymer. And preferably compatible with both polymer components. When compatible with both polymer components, at least two phases of a mixture mainly composed of the first polymer and the curable resin precursor and a mixture mainly composed of the second polymer and the curable resin precursor Phase separate.

  Specifically, when a plurality of polymers are a combination of a cellulose derivative and a (meth) acrylic resin having a polymerizable group, and the curable resin precursor is a polyfunctional (meth) acrylate, the polymers are non-phased. In addition, the combination of a (meth) acrylic resin having a polymerizable group and a polyfunctional (meth) acrylate is incompatible and phase separated, and the cellulose derivative and the polyfunctional (meth) acrylate are compatible. It may be.

  When the selected polymers and curable resin precursors are highly compatible, the polymer or the polymer and the precursor do not effectively phase separate during the drying process to evaporate the solvent, and function as an anti-Newton ring layer Decreases. The phase separation of multiple polymers and precursors is confirmed by visually checking whether the residual solids become cloudy in the process of preparing a homogeneous solution using good solvents for both components and gradually evaporating the solvent. This can be easily determined.

  Furthermore, the difference in refractive index between the polymer and the cured or crosslinked resin, and the difference in refractive index between the plurality of polymers (difference in refractive index between the first polymer and the second polymer) are, for example, 0.001 to 0.001. 2, Preferably about 0.05-0.15 may be sufficient.

  In spinodal decomposition, a co-continuous phase structure is formed with the progress of phase separation, and when the phase separation further proceeds, the continuous phase becomes discontinuous by its surface tension, resulting in a droplet phase structure (spherical, true spherical, disc-like) Or an island-like sea-island structure such as an ellipsoid). Therefore, an intermediate structure between the co-continuous phase structure and the droplet phase structure (phase structure in the process of transition from the co-continuous phase to the droplet phase) can be formed depending on the degree of phase separation. The phase separation structure of the anti-Newton ring layer may be a sea-island structure (droplet phase structure or a phase structure in which one phase is independent or isolated), a co-continuous phase structure (or network structure), and a co-continuous phase structure. And an intermediate structure in which a droplet phase structure is mixed. By these phase separation structures, a gentle and fine relief structure can be formed on the surface of the anti-Newton ring layer after solvent drying.

  Thus, the haze of the anti-Newton ring layer having a concavo-convex shape formed on the surface by phase separation can be selected from the range of about 0.1 to 50%, for example, 0.1 to 30%, preferably Is 0.5 to 20%, more preferably about 1 to 15% (particularly 2 to 8%). For example, in the case of electronic paper, it may be 1 to 30%, preferably 5 to 20%, and more preferably about 10 to 15%.

  Further, unlike the anti-Newton ring layer formed by the method of blending particles, the anti-Newton ring layer using phase separation does not contain fine particles that cause scattering inside the layer in the anti-Newton ring layer. For this reason, the haze inside the layer (internal haze causing scattering inside the layer) is low, for example, about 0 to 1%, preferably 0 to 0.8% (for example, 0.01 to 0.8). %), More preferably about 0 to 0.5% (for example, 0.1 to 0.5%). The internal haze is applied by coating the resin layer from above to flatten the surface irregularities of the anti-Newton ring layer, or by bonding the surface irregularities of the smooth transparent film and the anti-Newton ring layer through the transparent adhesive layer. It can be measured by measuring haze.

  In the phase separation structure, a droplet phase structure having at least island-like domains is advantageous from the viewpoint of forming a surface uneven structure and increasing the surface hardness. When the phase separation structure composed of the polymer and the precursor (or cured resin) is a sea-island structure, the polymer component may form a sea phase, but from the viewpoint of surface hardness, the polymer component is an island. Preferably, a domain is formed. Note that by forming the island-like domains, fine irregularities can be formed on the surface of the anti-Newton ring layer after drying.

  Furthermore, the average distance between the domains of the phase separation structure is usually substantially regular or periodic. For example, the average interphase distance between domains is, for example, about 1 to 70 μm (for example, 1 to 40 μm), preferably 2 to 50 μm (for example, 3 to 30 μm), and more preferably about 5 to 20 μm (for example, 10 to 20 μm). There may be.

  The ratio (weight ratio) between the polymer and the curable resin precursor is not particularly limited, and can be selected, for example, from the range of the former / the latter = 5/95 to 95/5, and preferably 5 from the viewpoint of surface hardness. / 95 to about 60/40, more preferably about 10/90 to 50/50, particularly about 10/90 to 40/60. In particular, when a cellulose derivative is used for all or part of the polymer, the ratio (weight ratio) between the polymer and the curable resin precursor is, for example, the former / the latter = 10/90 to 80/20, preferably 20/80. It is about -70/30, More preferably, it is about 30 / 70-50 / 50.

(2) Anti-Newton ring layer in which particles are blended The anti-Newton ring layer in which particles are blended is to blend particles in the polymer component or curable resin precursor exemplified in the anti-Newton ring layer using the phase separation. Thus, a concavo-convex structure derived from particles is formed. The polymer component or the curable resin precursor is preferably a (meth) acrylic polymerizable composition, for example, urethane (meth) acrylate, from the viewpoints of transparency and mechanical properties.

  The particles include organic fine particles and inorganic fine particles. Examples of the resin constituting the organic fine particles include thermoplastic resins (for example, acrylic resins such as polymethyl methacrylate, polycarbonate, styrene resins such as polystyrene and styrene-acrylonitrile copolymer, and polyvinyl chloride resins). , Crosslinked thermoplastic resins [for example, crosslinked olefin resins (for example, crosslinked polyethylene, crosslinked polypropylene, etc.), crosslinked styrene resins (for example, crosslinked polystyrene, crosslinked polydivinylbenzene, crosslinked polyvinyltoluene, crosslinked styrene-methyl methacrylate copolymer) And the like), cross-linked acrylic resins (for example, cross-linked polymethyl methacrylate, etc.), thermosetting resins (melamine resin, urea resin, aminobenzoguanamine resin, silicone resin, epoxy resin, polyurethane, etc.) and the like.These organic fine particles can be used alone or in combination of two or more.

  Examples of inorganic compounds constituting the inorganic fine particles include simple metals, metal oxides, metal sulfates (calcium sulfate, barium sulfate, etc.), metal silicates (calcium silicate, aluminum silicate, magnesium silicate, magnesium aluminosilicate, etc.), Metal phosphates (calcium phosphate, magnesium phosphate, etc.), metal carbonates (magnesium carbonate, heavy calcium carbonate, light calcium carbonate, etc.), metal hydroxides (aluminum hydroxide, calcium hydroxide, magnesium hydroxide, etc.), Examples thereof include silicon compounds (white carbon, glass, etc.), natural minerals (zeolite, diatomaceous earth, calcined siliceous earth, alumina, talc, mica, kaolin, sericite, bentonite, montmorillonite, smectite, clay, etc.).

  These particles can be used alone or in combination of two or more. Among these particles, (crosslinked) styrene resin particles, (crosslinked) acrylic resin particles, polycarbonate particles, and the like are preferable from the viewpoint of transparency and affinity with a polymer component or a curable resin precursor.

  The shape of the particle is not particularly limited, and examples thereof include a spherical shape, an ellipsoidal shape, a polygonal shape (polygonal pyramid shape, a rectangular parallelepiped shape, a rectangular parallelepiped shape, etc.), a plate shape, a rod shape, and an indefinite shape. From the point of forming, isotropic shape such as substantially spherical shape is preferable.

  Although the refractive index of particle | grains can be selected according to the kind of a polymer component or curable resin precursor, for example, 1.40-1.60, Preferably it is 1.42-1.59, More preferably, it is 1.45. It may be about 1.58.

  The average particle diameter of the particles is, for example, about 0.1 to 10 μm, preferably 1 to 8 μm, more preferably about 2 to 6 μm (particularly 3 to 5 μm).

  The ratio of the particles is, for example, 1 to 50 parts by weight, preferably 3 to 40 parts by weight, more preferably 5 to 30 parts by weight (particularly 10 to 20 parts) with respect to 100 parts by weight in the polymer component or the curable resin precursor. Part by weight).

  The anti-Newton ring layer in which the particles are blended can be produced by a conventional method such as melt kneading or mixing using a solvent. For example, the anti-Newton ring layer may be produced by the production method described in JP-A-6-18706.

  In the present invention, among the anti-Newton ring layers, an anti-Newton ring layer utilizing phase separation is particularly preferable because a uniform and smooth uneven shape can be formed and the anti-Newton ring property is excellent.

  For the anti-Newton ring layer, various additives such as stabilizers (antioxidants, UV absorbers, etc.), surfactants, water-soluble polymers, fillers, cross-linking agents, coupling agents, flame retardants, lubricants , Waxes, preservatives, viscosity modifiers, thickeners, leveling agents, antifoaming agents, and the like may be included.

  The thickness of the anti-Newton ring layer (thickness between the tops of the protrusions in the concavo-convex shape) may be, for example, about 0.3 to 20 μm, preferably about 1 to 18 μm (for example, 3 to 16 μm), Usually, it is about 4-15 micrometers (especially 5-13 micrometers). The functional layers other than the anti-Newton ring layer may have the same thickness. In the present invention, as will be described later, a laminated film can be formed by coating, and the adhesiveness is excellent, so that the thickness of a functional layer such as an anti-Newton ring layer or a hard coat layer can be increased, thereby improving the visibility of a touch panel or the like. it can.

(Transparent conductive layer)
As the transparent conductive layer, a conventional transparent conductive layer used as a transparent electrode can be used. The transparent conductive layer can be any of a transparent conductive layer composed of a conductive inorganic compound and a transparent conductive layer composed of a conductive polymer. May be.

(1) As the conductive inorganic compound transparent conductive layer conductive inorganic compound composed of, for example, metal oxides [e.g., indium oxide _{(InO 2, In 2 O 3} , In 2 O 3 -SnO 2 composite oxide (ITO), etc.), tin oxide _{(SnO 2, SnO 2 -Sb 2} O 5 composite oxide, fluorine-doped tin oxide (FTO), etc.), zinc oxide _{(ZnO, ZnO-Al 2 O} 3 composite oxide, etc.) , Metals (for example, gold, silver, platinum, palladium) and the like. These conductive inorganic compounds can be used alone or in combination of two or more. Of these conductive inorganic compounds, metal oxides such as ITO films are widely used.

  The transparent conductive layer composed of the conductive inorganic compound can be formed by a conventional method such as sputtering, vapor deposition, chemical vapor deposition (usually sputtering). Such a transparent conductive layer may be, for example, the transparent conductive layer described in JP-A-2009-76544, JP-A-4165173, and JP-A-2004-14984.

  The surface resistance of the transparent conductive layer composed of the conductive inorganic compound may be, for example, about 10 to 1000Ω, preferably about 15 to 500Ω, and more preferably about 20 to 300Ω.

  The thickness of the transparent conductive layer composed of the conductive inorganic compound is not particularly limited, and may be about 1 to 1000 nm, preferably about 5 to 500 nm, and more preferably about 10 to 400 nm (particularly 20 to 300 nm).

  In the present invention, even when the transparent conductive layer is formed of a conductive inorganic compound, the keystroke durability and sliding durability of the touch panel can be improved.

(2) Conductive layer composed of a conductive polymer The conductive polymer is not particularly limited as long as it is a transparent and conductive conjugated polymer material, and is a conventional conductive polymer such as a polyacetylene polymer. (Eg, polyacetylene), polythiophene polymer (eg, polythiophene), polyphenylene polymer (eg, polyparaphenylene), polypyrrole polymer (eg, polypyrrole), polyaniline polymer (eg, polyaniline) And the like, and polyester polymers modified with acrylic polymers (for example, polyester polymers with a high degree of polymerization modified with a copolymer of isobutyl methacrylate and butyl acrylate). These conductive polymers can be used alone or in combination of two or more. For example, a polythiophene polymer and a polyester polymer modified with an acrylic polymer may be combined. Of these conductive polymers, polythiophene-based polymers, polypyrrole-based polymers, and polyaniline-based polymers are widely used because they are soluble in aqueous solvents and have excellent handleability, and have excellent conductivity, chemical stability, and transparency. A polythiophene polymer is preferable from the viewpoint of superiority.

The polythiophene polymer usually has poly (thiophene-2,5-diyl) units. The thiophene may be a substituent (usually a 3- and / or 4-position substituent). Examples of the substituted thiophene include monoalkylthiophene (for example, C _1-10 alkyl-thiophene such as 3-methylthiophene, 3-ethylthiophene, 3-propylthiophene, and 3-hexylthiophene), 3,4-dihydroxythiophene. Dialkoxythiophene (eg, diC _1-6 alkoxy-thiophene such as 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene), alkylenedioxythiophene (eg, 3 , 4-methylenedioxythiophene, 3,4-ethylenedioxythiophene, C _1-4 alkylenedioxythiophene such as 3,4-propylenedioxythiophene), cycloalkylenedioxythiophene [for example, 3,4- (1,2-cyclohe Siren) C _5-12 cycloalkylene, such dioxythiophene - such dioxythiophene] and the like. In addition, alkylenedioxythiophene and cycloalkylenedioxythiophene are an alkylene group and a cycloalkylene group, a _C1-12 alkyl group such as a methyl group or an ethyl group, or a _C5-12 aryl group such as a phenyl group. May be substituted. These thiophenes or substituted thiophenes can be used alone or in combination of two or more. Of these thiophenes and substituted thiophenes, usually, monoalkylthiophenes such as thiophene and 3-hexylthiophene, alkylenedioxythiophenes such as 3,4-ethylenedioxythiophene, 3,4- (1,2-cyclohexylene) Cycloalkylenedioxythiophene such as dioxythiophene is used, and 3,4-alkylenedioxythiophene such as 3,4-ethylenedioxythiophene and 3,4-diethoxy are used in terms of moldability and conductivity. Preferred are 3,4-dialkoxy-thiophenes such as thiophene, especially 3,4-C _1-4 alkylenedioxythiophene. The polythiophene polymer may be a copolymer having such a thiophene unit and a vinylene unit.

Specific examples of the polythiophene-based polymer include poly (3-C _1-8 alkyl-thiophene) such as polythiophene and poly (3-hexylthiophene), poly (3,4-ethylenedioxythiophene), and poly ( 3,4-propylenedioxythiophene), poly [3,4- (1,2-cyclohexylene) dioxythiophene] and other poly (3,4- (cyclo) alkylenedioxythiophene), polythienylene vinylene and the like Is mentioned.

  The transparent conductive layer composed of the conductive polymer may further contain an anionic polymer. In particular, the conductive polymer is polymerized in the presence of an anionic polymer in the polymerization process. For example, since a polythiophene polymer is usually oxidatively polymerized in the presence of an anionic polymer, it can be used in combination with an anionic polymer.

  Examples of the anionic polymer include a polymer having at least one anionic group selected from a carboxyl group and a sulfonic acid group or a salt thereof, for example, a polymer having a carboxyl group or a salt thereof [for example, poly (meth) acrylic Acid, (meth) acrylic acid-maleic anhydride copolymer, (meth) acrylic acid-based polymer such as (meth) acrylic acid-methyl methacrylate copolymer or salt thereof], sulfonic acid group or salt thereof. And polymers having a carboxyl group and a sulfonic acid group or a salt thereof (for example, a (meth) acrylic acid-styrene sulfonic acid copolymer). It is done. Examples of the salt of the anionic polymer include alkali metal salts such as sodium salt and potassium salt, alkyl salts such as ammonium salt and triethylamine, and organic amine salts such as alkanolamine. These anionic polymers can be used alone or in combination of two or more. Of these anionic polymers, a polymer having a sulfonic acid group, such as polystyrene sulfonic acid, is preferable.

  The number average molecular weight of the anionic polymer is, for example, 1000 to 2,000,000, preferably 2000 to 1,000,0000, and more preferably about 2000 to 500,000.

  The proportion of the anionic polymer is, for example, 10 to 2000 parts by weight, preferably 30 to 1000 parts by weight, more preferably 50 to 500 parts by weight (particularly 100 to 300 parts by weight) with respect to 100 parts by weight of the conductive polymer. Degree.

  The transparent conductive layer composed of the conductive polymer may contain various additives similar to those of the phase separation layer. In particular, a surfactant, a silane coupling agent, or the like may be included.

  The thickness of the transparent conductive layer composed of the conductive polymer is, for example, 0.01 to 1 μm, preferably 0.01 to 0.5 μm, more preferably 0.03 to 0.3 μm (particularly 0.05 to 0.00). 2 μm).

(Other functional layers)
In the conductive laminated film of the present invention, another functional layer (second functional layer) may be formed on the other surface of the base film. Examples of other functional layers include conventional functional layers such as a hard coat layer, a light scattering layer, an antiglare layer, an antireflection layer, and a low refractive index layer. Of these functional layers, a hard coat layer, an antiglare layer, and the like are widely used. As the hard coat layer, among the cured products of the composition containing urethane (meth) acrylate and / or polymerizable vinyl-based components exemplified in the cushion layer, cured products having a glass transition temperature higher than that of the cushion layer. A polymerizable composition containing urethane (meth) acrylate is particularly preferable because it can be used and has transparency, flexibility (flexibility), and scratch resistance required for a touch panel. In particular, in the case of vapor deposition, it is preferable to provide hard coat layers on both sides in order to prevent the oligomer component from migrating (depositing) from the transparent substrate to the film surface. Further, as the antiglare layer, the anti-Newton ring layer may be formed as an antiglare layer.

  The thickness of the other functional layer may be the same as that of the first functional layer, and may be, for example, about 0.3 to 2 μm, preferably about 1 to 18 μm (for example, 3 to 16 μm). Usually, it is about 2 to 12 μm (particularly 5 to 10 μm).

(Characteristics of transparent conductive laminated film)
The transparent conductive laminated film of the present invention achieves both high transparency and flexibility. The total light transmittance of the transparent conductive laminated film is, for example, about 80 to 100%, preferably 85 to 95%, and more preferably about 87 to 92% (particularly 89 to 91%). A haze can be selected from the range of about 0.1 to 10%, for example, 0.1 to 5%, preferably 0.2 to 3%, and more preferably about 0.5 to 2.5%.

The transparent conductive laminated film of the present invention has excellent flexibility, and the Martens hardness on the surface on the first functional layer side (the surface on the viewing side or the surface of the first functional layer) before forming the transparent conductive layer is 100 N / mm ² or less, for example, 5~80N / mm ^2, preferably 10 to 50 N / mm ^2, more preferably 15~40N / mm ² (in particular 20-30 N / mm ²⁾ about. On the other hand, the Martens hardness on the surface (the second functional layer or the surface of the transparent substrate film) on the other surface (back surface) side of the substrate film is, for example, 100 to 300 N / mm ² , preferably 120 to 250 N / It may be about mm ² , more preferably about 150 to 220 N / mm ² (particularly 160 to 200 N / mm ² ).

  The indentation depth on the surface of the first functional layer before forming the transparent conductive layer is, for example, 3 μm or more, for example, 3 to 15 μm, preferably 4 to 10 μm, more preferably 4.5 to 8 μm ( In particular, it is about 5 to 7 μm. On the other hand, the indentation depth in the surface of the other surface side of a base film is 0.5-10 micrometers, for example, Preferably it is 1-8 micrometers, More preferably, it is about 1.5-5 micrometers (especially 2-3 micrometers).

  Furthermore, when an anti-Newton ring layer having a phase separation structure is formed as the first functional layer, the average inter-phase distance of the domains is substantially regular or periodic in the phase separation structure. Therefore, the light that enters and passes through the transparent conductive laminated film exhibits a scattered light maximum at a specific angle away from the straight transmitted light due to Bragg reflection corresponding to the interphase average distance (or the periodicity of the surface uneven structure). . That is, a transparent conductive laminated film having an anti-Newton ring layer isotropically transmits incident light and scatters or diffuses, but scattered light (transmitted scattered light) has a scattering angle shifted from the scattering center [for example, 0.1 to 10 °, preferably 0.2 to 8 °, and more preferably about 0.3 to 5 ° (particularly about 0.5 to 2 °)]. Therefore, the scattered light due to the surface unevenness does not adversely affect the profile of the straight transmitted light, and unlike the conventional fine particle dispersion type anti-Newton ring layer, the Newton ring is suppressed and the image of the display device is suppressed. Can eliminate glare.

  As the determination of the maximum value of the transmitted light scattering intensity, in the angular distribution profile of the scattered light intensity, in addition to the case where the peak is separated into peaks, the shoulder peak or the flat peak is considered to have the maximum value, That angle can be the peak angle.

  In addition, as shown in FIG. 1, the angular distribution of the light which permeate | transmitted the laminated | multilayer film which has an anti-Newton ring layer is the measurement provided with the optical light receiver 4 installed in the laser light source 1, such as He-Ne laser, etc. It can be measured using a device. In this example, the sample 3 can be irradiated with laser light from the laser light source 1 via the ND filter 2, and the scattered light from the sample can be changed at a scattering angle θ with respect to the optical path of the laser light. And it detects with the detector (light receiver) 4 provided with the photoelectron amplifier tube, and measures the relationship between scattering intensity and scattering angle (theta).

  In addition, the evaluation of glare and character blur in the display unit of the display device arranged at the lower part of the touch panel can be evaluated by visual reflection of a fluorescent lamp and using a gloss meter according to JlS K7105. Furthermore, glare and character blur can be evaluated using a high-definition liquid crystal display device with a resolution of about 200 ppi, and more simply a combination of a high-definition CRT display device or a color filter for liquid crystal with about 150 ppi and a backlight. It can be visually evaluated using an evaluation device.

  The transmission image definition of the transparent conductive laminated film of the present invention is, for example, about 50 to 100%, preferably about 60 to 99%, more preferably about 65 to 90% when an optical comb having a width of 0.5 mm is used. is there. When the transmitted image definition is in the above range, the scattering of the linearly transmitted light is small, so even when the touch panel is arranged on a high-definition display device, the scattering from each pixel is reduced, and as a result Can prevent glare.

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

C (%) = [(M−m) / (M + m)] × 100
That is, the closer the value of C is to 100%, the smaller the blurring of the image by the Newton ring prevention film [Reference: Suga, Mitamura, Painting Technology, July 1985 issue].

  The transparent conductive laminated film of the present invention may be further combined with other optical elements (for example, various optical elements disposed in an optical path such as a polarizing plate, a phase difference plate, and a light guide plate). That is, the transparent conductive laminated film may be disposed or laminated on at least one optical path surface of the optical element. For example, the laminated film may be laminated on at least one surface of the retardation plate, and an electrode substrate may be disposed or laminated on the light exit surface of the light guide plate. The transparent conductive laminated film combined with a polarizing plate or a retardation film can be suitably used for an inner touch panel having an antireflection function.

[Method for producing transparent conductive laminated film]
The transparent conductive laminated film of the present invention is produced by coating each layer on a base film. Therefore, in the present invention, since a laminated film is produced without being laminated (laminated), a laminated film free from foreign matters and bubbles can be obtained by a simple method.

  The transparent conductive laminated film of the present invention can be produced by using a conventional method, the lamination order is not particularly limited, and each layer may be formed on the base film according to the laminated structure. In the case of forming the second functional layer, for example, a method of sequentially forming a cushion layer, a first functional layer, and a transparent conductive layer after forming the second functional layer on the base film may be used. A method of forming the second functional layer after sequentially forming the cushion layer, the first functional layer, and the transparent conductive layer on the film may be used.

(Cushion layer)
The cushion layer is manufactured through a coating process in which a polymerizable composition containing urethane (meth) acrylate is applied onto a base film, and a curing process in which the applied polymerizable composition is cured by irradiation with active energy rays. Is done.

  As a coating method of the polymerizable composition, conventional methods such as roll coater, air knife coater, blade coater, rod coater, reverse coater, bar coater, comma coater, dip squeeze coater, die coater, gravure coater, microgravure coater Examples include coater, silk screen coater method, dip method, spray method, spinner method and the like. Of these methods, the bar coater method and the gravure coater method are widely used. If necessary, the coating solution may be applied a plurality of times.

  When the polymerizable composition contains an organic solvent, it may be dried as necessary after coating. Drying may be performed at a temperature of about 50 to 150 ° C., preferably 60 to 140 ° C., and more preferably about 70 to 130 ° C., for example.

  In the curing step, the polymerizable composition may be cured by heating depending on the type of the polymerization initiator, but it can usually be cured by irradiation with active energy rays. As active energy rays, heat and / or light energy rays can be used, and it is particularly useful to use light energy rays. As light energy rays, radiation (gamma rays, X-rays, etc.), ultraviolet rays, visible rays, electron beams (EB), etc. can be used, and usually ultraviolet rays and electron beams are often used. In particular, when producing a sheet that can be polymerized without using a polymerization initiator and has high weather resistance, it may be irradiated with an electron beam.

As the light source, for example, in the case of ultraviolet rays, a Deep UV lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a halogen lamp, a laser light source (light source such as a helium-cadmium laser or an excimer laser) may be used. it can. The amount of irradiation light (irradiation energy) varies depending on the thickness of the coating film, but may be, for example, about 50 to 10,000 mJ / cm ² , preferably 70 to 7000 mJ / cm ² , and more preferably about 100 to 5000 mJ / cm ² .

  In the case of an electron beam, a method of irradiating an electron beam with an exposure source such as an electron beam irradiation apparatus can be used. The irradiation amount (dose) varies depending on the thickness of the coating film, but is, for example, about 1 to 200 kGy (gray), preferably 5 to 150 kGy, and more preferably 10 to 100 kGy (particularly 20 to 80 kGy). The acceleration voltage is, for example, about 10 to 1000 kV, preferably about 50 to 500 kV, and more preferably about 100 to 300 kV.

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

(First functional layer)
When forming an anti-Newton ring layer using phase separation as the first functional layer, the anti-Newton ring layer is formed from a liquid phase (or liquid composition) containing a polymer, a curable resin precursor, and a solvent. By spinodal decomposition accompanying evaporation of the solvent, it can be produced through a phase separation step for forming a phase separation structure and a curing step for curing the curable resin precursor to form an anti-Newton ring layer.

  The phase separation step usually includes a step of applying or casting a mixed liquid (particularly a liquid composition such as a homogeneous solution) containing the polymer, a curable resin precursor, and a solvent to the support, and a coating layer or a flow. And a step of evaporating the solvent from the layered layer to form a phase separation structure having a regular or periodic average interphase distance. In a preferred embodiment, a composition containing the thermoplastic resin, a photocurable compound, a photopolymerization initiator, and a solvent soluble in the thermoplastic resin and the photocurable compound can be used as the mixed solution. An anti-Newton ring layer is formed by curing the photocuring component of the phase separation structure formed by spinodal decomposition by light irradiation. In another preferred embodiment, a composition containing a plurality of incompatible polymers, a photocurable compound, a photopolymerization initiator, and a solvent can be used as the mixed solution, which is formed by spinodal decomposition. The anti-Newton ring layer is formed by curing the photocured component of the phase separated structure by light irradiation.

  In the wet spinodal decomposition, the solvent can be selected according to the type and solubility of the polymer and curable resin precursor, and at least the solid content (a plurality of polymers and curable resin precursors, reaction initiators, other additives) is selected. Any solvent that can be uniformly dissolved may be used. Examples of such solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons ( Cyclohexane etc.), aromatic hydrocarbons (toluene, xylene etc.), halogenated carbons (dichloromethane, dichloroethane etc.), esters (methyl acetate, ethyl acetate, butyl acetate etc.), water, alcohols (ethanol, isopropanol, Butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl ether (1-methoxy-2-propanol), etc.), cellosolve acetates, sulfoxides (dimethylsulfate) Kishido etc.), amides (dimethylformamide, dimethylacetamide, etc.), and others. The solvent may be a mixed solvent.

  Among these solvents, it is preferable to use a solvent having a boiling point of 100 ° C. or higher at normal pressure. Furthermore, it is preferable that the solvent is composed of at least two solvents having different boiling points from the viewpoint of forming a fine and regular uneven structure on the surface. Moreover, the boiling point of a high boiling point solvent is 100 degreeC or more, Usually, it is about 100-200 degreeC, Preferably it is 105-150 degreeC, More preferably, it is about 110-130 degreeC. In particular, it is preferable to use a combination of at least one solvent having a boiling point of 100 ° C. or higher and at least one solvent having a boiling point of less than 100 ° C. When such a mixed solvent is used, the low boiling point solvent generates a temperature difference between the upper layer and the lower layer due to evaporation, and the high boiling point solvent remains in the coating film and maintains fluidity.

Examples of the solvent having a boiling point of 100 ° C. or higher at normal pressure include alcohols (C _4-8 alkyl alcohols such as butanol, pentyl alcohol and hexyl alcohol), and alkoxy alcohols (C _1-6 such as methoxypropanol and butoxyethanol). Alkoxy C _2-6 alkyl alcohol), alkylene glycols (C _2-4 alkylene glycol such as ethylene glycol and propylene glycol), ketones (cyclohexanone, etc.) and the like. These solvents can be used alone or in combination of two or more. Of these, C _4-8 alkyl alcohols such as butanol, C _1-6 alkoxy C _2-6 alkyl alcohols such as methoxypropanol and butoxyethanol, C _2-4 alkylene glycols such as ethylene glycol, and the like are preferable.

  The ratio of solvents having different boiling points is not particularly limited, but when a solvent having a boiling point of 100 ° C. or higher and a solvent having a boiling point of less than 100 ° C. are used in combination (when two or more types are used in combination, the total weight ratio), for example The former / the latter = 10/90 to 70/30, preferably 10/90 to 50/50, more preferably 15/85 to 40/60 (particularly about 20/80 to 40/60).

  Moreover, when apply | coating a liquid mixture or a coating liquid to a base film, you may select the solvent which does not melt | dissolve, erode, or swell a base film according to the kind of base film. For example, when a triacetyl cellulose film is used as the base film, a laminated film can be formed without impairing the properties of the film by using, for example, tetrahydrofuran, methyl ethyl ketone, isopropanol, toluene, etc. as a solvent for the mixed solution or coating solution. .

  The concentration of the solute (polymer and curable resin precursor, reaction initiator, other additives) in the mixed solution can be selected within a range where phase separation occurs and a range where casting properties and coating properties are not impaired. It is about 80% by weight, preferably 5 to 60% by weight, more preferably about 15 to 40% by weight (especially 15 to 35% by weight).

  As the coating method, the same method as the cushion layer coating method described above can be used. After casting or coating the mixed solution, the temperature is lower than the boiling point of the solvent (for example, 1 to 120 ° C., preferably 5 to 80 ° C., more preferably 10 to 60 ° C., particularly 10 to 50 than the boiling point of the solvent). By evaporating the solvent at a temperature as low as about 0 ° C., phase separation due to spinodal decomposition can be induced. The evaporation of the solvent is usually drying, for example, 30 to 200 ° C. (for example, 30 to 100 ° C.), preferably 40 to 120 ° C., more preferably about 50 to 80 ° C., depending on the boiling point of the solvent. It can be done by drying with.

  In order to form a fine concavo-convex structure on the surface, it is applied to a base film, cast or applied, and then immediately put into a dryer such as an oven and dried for a certain period of time ( For example, it is allowed to stand for 1 second to 1 minute, preferably 3 to 30 seconds, more preferably about 5 to 20 seconds), room temperature or room temperature (for example, 0 to 40 ° C., preferably about 5 to 30 ° C.), and then dried. You may throw it into the machine. Also, the amount of dry air is not particularly limited, but if the air flow is too strong, the air is dried and solidified before the concavo-convex structure is formed. Therefore, the amount of dry air is 50 m / min or less (for example, 1 to 50 m / min), preferably May be about 1 to 30 m / min, more preferably about 1 to 20 m / min.

  By such spinodal decomposition accompanied by evaporation of the solvent, regularity or periodicity can be imparted to the average distance between the domains of the phase separation structure.

  The phase separation structure formed by spinodal decomposition can be immediately fixed by curing the precursor in the curing step. Curing of the precursor can be performed by heating, light irradiation, or a combination of these methods depending on the type of the curable resin precursor. As long as it has the said phase-separation structure, a heating temperature can be selected from an appropriate range, for example, about 50-150 degreeC, and may be selected from the temperature range similar to the said phase-separation process. The light irradiation can use the same method as the cushion layer irradiation method described above. As with the cushion layer, the curing method is often ultraviolet rays or electron beams.

  In addition, when forming an anti-Newton ring layer, a hard coat layer, a low refractive index layer, etc. which mix | blended particle | grains as a 1st functional layer, it can form by the method similar to a cushion layer. Furthermore, when the second functional layer is formed, the second functional layer can also be manufactured by the same method as the first functional layer.

(Transparent conductive layer)
The transparent conductive layer composed of the conductive inorganic compound is not particularly limited as long as it is a method capable of forming a thin film containing a metal or a metal compound, and can be formed using a conventional film forming method. Examples of the film formation method include physical vapor deposition (PVD) [for example, vacuum deposition, flash deposition, electron beam deposition, ion beam deposition, ion plating (for example, HCD, electron beam RF). Method, arc discharge method, etc.), sputtering method (eg, DC discharge method, radio frequency (RF) discharge method, magnetron method, etc.), molecular beam epitaxy method, laser ablation method, etc.], chemical vapor phase method (CVD) [eg, , Thermal CVD method, plasma CVD method, MOCVD method (metal organic chemical vapor deposition method), photo CVD method, etc.], ion beam mixing method, ion implantation method and the like. Of these film formation methods, physical vapor deposition methods such as vacuum deposition, ion plating, and sputtering, and chemical vapor deposition are widely used, and sputtering and plasma CVD (particularly sputtering) are preferred. .

  The transparent conductive layer composed of a conductive polymer can be produced by applying a liquid composition containing a conductive polymer and drying it. In the formation process of a transparent conductive layer, it can manufacture by apply | coating the coating liquid (liquid composition containing a conductive polymer) of a transparent conductive layer on a 1st functional layer. For the application or casting of the coating liquid for the transparent conductive layer, a conventional application means similar to the cushion layer can be used. In this invention, after apply | coating a coating liquid on a 1st functional layer, a transparent conductive layer can be normally formed by drying a coating layer.

  The solvent in the liquid composition can be selected according to the type of the conductive polymer. For example, in the case of a polythiophene polymer, water or an aqueous solvent may be used. Examples of aqueous solvents (especially water-miscible solvents) include alcohols (methanol, ethanol, propanol, isopropanol, isobutanol, ethylene glycol, propylene glycol, etc.), ketones (acetone, methyl ethyl ketone, etc.), nitriles (acetonitrile, etc.) ), Ethers (dioxane, tetrahydrofuran, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), carbitols, etc. and a mixed solvent of water may be used. A hydrophilic solvent can be used individually or in combination of 2 or more types. In the present invention, usually, water alone or a mixed solvent of water and alcohols is used. In particular, in order to improve the adhesion to the functional layer, a solvent composed of at least a lower alcohol such as isopropanol may be used.

  The concentration of the conductive polymer in the liquid composition is, for example, 0.01 to 5% by weight, preferably 0.05 to 3% by weight, more preferably 0.1 to 2% by weight (particularly 0.3 to 1% by weight). %) Degree.

  Note that the transparent conductive layer is usually formed in a planar shape in the analog method and in a stripe shape in the digital method, depending on the type of the touch panel. As a method of forming the transparent conductive layer in a planar shape or a stripe shape, for example, a method of forming a transparent conductive layer on the entire surface of the first functional layer and then patterning the transparent conductive layer into a planar shape or a stripe shape, or a pattern shape in advance. And the like.

[Touch panel]
The touch panel (especially resistive film type touch panel) of the present invention includes the transparent conductive laminated film as an upper transparent electrode substrate (transparent electrode on the viewing side). FIG. 2 is a schematic sectional view showing an example of the touch panel of the present invention. In this touch panel 10, an upper electrode substrate 11 and a lower electrode substrate 13 are laminated via a spacer 12, and the transparent conductive layer 11 a of the upper electrode substrate 11 and the transparent conductive layer 13 a of the lower electrode substrate 13 face each other, It is disposed on the liquid crystal panel 20.

  In the upper electrode substrate 11, a hard coat layer 11e is formed on one surface (panel front side, viewing side, or upper surface) of a transparent base film 11d made of a transparent plastic film, and the other surface (panel back side or lower portion). The cushion layer 11c is formed on the surface. An anti-Newton ring layer 11b using phase separation is formed on the surface of the cushion layer 11c (the panel back side or the lower surface). The transparent conductive layer 11a is formed on the surface of the anti-Newton ring layer 11b (the back side or lower surface of the panel), and the surface of the anti-Newton ring layer 11b has a uniform and regular uneven structure. The surface of 11a also has an uneven structure that follows the uneven structure of the anti-Newton ring layer 11b. When the upper electrode substrate 11 is pressed by a pressing member such as a finger or a pen, the transparent conductive layer 11a is bent and comes into contact with the transparent conductive layer 13a of the lower electrode substrate 13 to perform position detection. In the present invention, since the cushion layer 11c has high flexibility and adhesion, deterioration of the transparent conductive layer 11a can be suppressed even when the upper electrode substrate 11 is repeatedly pressed. Furthermore, in this transparent conductive laminated film, since the surface of the transparent conductive layer 11a of the upper transparent electrode 11 has a uniform uneven structure following the anti-Newton ring layer 11b, the upper transparent electrode 11 is pressed. In addition, it is possible to suppress the generation of Newton rings due to interference of interface reflected light between the space (air layer) formed by the upper transparent electrode 11 and the spacer 12. Other functions such as a hard coat layer may be formed instead of the anti-Newton ring layer 11b.

  The spacer 12 is made of a transparent resin, and is patterned on the surfaces of the transparent conductive layers 11a and 13a to hold the upper electrode substrate 11 and the lower electrode substrate 13 in a non-contact state when the touch panel is not pressed. It is formed in the shape of dots or dots. Such a spacer 12 is usually formed by patterning using a mask for light irradiation using a photocurable compound exemplified in the section of the curable resin precursor. The spacer does not need to be formed, and when formed, for example, the interval between adjacent spacers may be adjusted to, for example, about 0.1 to 20 mm (particularly 1 to 10 mm). The shape of the spacer is not particularly limited, and may be a cylindrical shape, a quadrangular prism shape, a spherical shape, or the like. The height of the spacer is, for example, about 1 to 100 μm, and is usually about 3 to 50 μm (particularly 5 to 20 μm). The average diameter of the spacer is, for example, about 1 to 100 μm, and usually about 10 to 80 μm (particularly 20 to 50 μm).

  The lower electrode substrate 13 is disposed below the upper electrode substrate 11 with the spacer 12 interposed, and is transparent on one surface (panel front side or upper surface) of the transparent substrate 13d made of glass. A conductive layer 13a is formed, and a hard coat layer 13e is formed on the other surface (panel back side or lower surface). Although the surface of the transparent conductive layer 13a of the lower electrode substrate 13 is smooth, like the upper electrode substrate 11, an anti-Newton ring layer may be formed to form an uneven structure on the surface. The anti-Newton ring effect may be improved by forming an anti-Newton ring layer on both the upper electrode substrate 11 and the lower electrode substrate 13. On the other hand, an anti-Newton ring layer may be formed on the lower electrode substrate 13 without forming an uneven structure on the upper electrode substrate 11. It is preferable to form an anti-Newton ring layer on one electrode substrate (particularly the upper electrode substrate) from the viewpoint that both the anti-Newton ring effect and the visibility of the display device disposed below the touch panel can be achieved. Unlike the transparent substrate 11d of the upper electrode substrate, the transparent substrate 13d does not need flexibility, and may be a non-flexible material such as a glass substrate, but has the same flexibility as the transparent substrate 11d. It may be a transparent plastic film.

  The touch panel 10 provided with such upper and lower electrode substrates is disposed on a liquid crystal panel 20 that is a liquid crystal display (LCD) device. In the present invention, since the cushion 11c is excellent in flexibility and excellent in transparency, the visibility of the liquid crystal panel 20 can be improved while suppressing the deterioration of the transparent conductive layer 11a. Further, the anti-Newton ring layer 11b can improve the light scattering intensity in a specific angle range while transmitting and scattering the transmitted light isotropically. Therefore, the anti-Newton ring layer 11b not only prevents the Newton ring but also visually recognizes the liquid crystal panel 20. Can also improve performance. Specifically, it is possible to suppress glare in the display unit of the liquid crystal panel, and to improve the clarity of the transmitted image, and to suppress character blur on the display surface.

  The liquid crystal display device may be a reflective liquid crystal display device that illuminates a display unit including a liquid crystal cell using external light, and a transmissive type that includes a backlight unit for illuminating the display unit. It may be a liquid crystal display device. In the reflective liquid crystal display device, incident light from outside can be taken in through the display unit, and the transmitted light that has passed through the display unit can be reflected by the reflecting member to illuminate the display unit. In the reflective liquid crystal display device, a touch panel in which a polarizing plate and a transparent conductive laminated film are combined may be disposed in the optical path ahead from the reflective member.

  In a transmissive liquid crystal display device, a backlight unit causes light from a light source (a tubular light source such as a cold cathode tube or a point light source such as a light-emitting diode) to enter from one side and exit from a front emission surface. A light guide plate (for example, a light guide plate having a wedge-shaped cross section) may be provided. If necessary, a prism sheet may be provided on the front side of the light guide plate.

  The display device disposed below the touch panel is not limited to a liquid crystal display device, and may be a display device such as a plasma display device or an organic or inorganic EL (electroluminescence) display device.

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

[Haze (HZ) and total light transmittance (TT)]
It measured based on JISK7136 about the transparent laminated film (laminated film before forming a transparent conductive layer) using the haze meter (Nippon Denshoku Co., Ltd. make, brand name "NDH-5000W").

[Tensile test]
The polymerizable composition is applied on a release film coated with silicon on a PET film with a coating thickness of 100 μm, cured by irradiating an electron beam with an acceleration voltage of 200 kV and an irradiation dose of 50 kGy, and peeled off from the release film. Using the obtained cured product, in accordance with JIS K7113, punched into a No. 7 dumbbell test piece, in a test environment with a temperature of 25 ° C. and a humidity of 50% RH, a tensile compression tester (manufactured by Orientec Co., Ltd., Tensylon UCT-5T) was used to obtain a stress-strain curve measured at a tensile speed of 2 mm / min. The tensile modulus was obtained from the obtained stress-strain curve.

[Glass transition temperature (Tg)]
About the hardened | cured material obtained by carrying out similarly to the said tension test, conditions of a temperature increase rate and angular frequency using a dynamic-viscoelasticity measuring apparatus (The TS instrument Japan Co., Ltd. make, RSA-III). Then, the loss elastic modulus (E ″) was measured. The glass transition temperature was determined from the maximum of E ″.

[Hue: b * value]
Using a spectrophotometer ("U-3300" manufactured by Hitachi High-Tech Fielding Co., Ltd.) for the transparent laminated film (laminated film before forming the transparent conductive layer), the b * value in transmission mode in accordance with JIS K7105 Was measured.

[Linear expansion coefficient]
A test piece was cut out from the cured product obtained in the same manner as in the tensile test, and used as a measurement sample. Using this measurement sample, thermal expansion, stress, and strain measurement equipment (“TMA / SS6100” manufactured by SII Nanotechnology Co., Ltd.) under the following measurement conditions, a linear expansion coefficient from −90 ° C. to 150 ° C. ( Displacement).

[Cushioning]
For the obtained transparent laminated film (laminated film before forming a transparent conductive layer), using a micro hardness tester (manufactured by Fischer Instruments), the measurement conditions are load F = 20 mN / 10 seconds, maximum test The load was set to 20 mN and the Martens hardness (HM) and the maximum indentation depth (hmax) were measured.

[Keystroke durability]
The obtained transparent conductive laminated film was used as the upper electrode substrate. Further, a glass substrate was used as the substrate, and the same ITO treatment was performed to provide a transparent conductive layer, thereby producing a lower electrode substrate. On the transparent conductive layer of the lower electrode substrate, a photocurable acrylic resin (manufactured by DuPont, Liston) was applied to form a layer, which was patterned and exposed to ultraviolet light to form a dot spacer. The dot spacer was a cylinder having a height of 8 μm and a diameter of 30 μm, and the spacer interval was 3 mm. At both ends, an electrode formed of silver paste and copper tape and a spacer (height of 86 μm) formed of double-sided tape were disposed. The touch panel was configured by disposing the thus prepared upper electrode substrate and lower electrode substrate so that the transparent electrode layers face each other. With respect to this touch panel, the keystroke durability was evaluated using a keystroke tester (“201-300-3” manufactured by Touch Panel Laboratories). The keystroke testing machine is equipped with a polyacetal pen (0.8 mmφ) as a touch pen. The keystroke durability is detected by repeatedly pressing the upper electrode substrate with the touch pen and contacting the lower electrode substrate to detect the waveform due to the load voltage. Was measured under the following conditions.

Keystroke load: 400g
Keystroke speed: 10 times / second (Hz)
Number of keystrokes: 500,000 to 4.8 million times Keystroke portion: Keystroke is 1 mm from the end of the spacer (double-sided tape).

[Sliding durability]
About the touchscreen produced by the keystroke durability test, sliding durability was evaluated using the sliding tester. In the sliding durability test, using a touch pen (“DS” genuine pen made by Nintendo Co., Ltd.), sliding the upper electrode substrate surface with a pen was repeated in the following conditions, and the detection position and The linearity (%) indicating the relationship with the voltage was obtained and the sliding durability was evaluated.

Sliding load: 500g
Sliding speed: 1 reciprocation / second Number of sliding times: 100,000 times, 200,000 times Keystroke part: sliding 2 mm from the end of the spacer (double-sided tape).

  Linearity (%) applies a voltage of 5 V to the transparent conductive laminated film, the output voltage at the measurement start position A is EA, the output voltage at the measurement end position B is EB, and the output voltage at the measurement point at a distance X from A Was calculated from the following formula, where EX is EX and the theoretical value is EXX.

EXX = X (EB-EA) / (BA) + EA
Linearity (%) = {| EXX-EX | / (EB-EA)} × 100
Evaluation is performed by comparing the maximum values of linearity (%). Generally, when linearity (%) exceeds 1.5%, it means that the electrical characteristics are poor.

[Composition ingredients]
High weather-resistant urethane acrylate: “EBECRYL8402” manufactured by Daicel Cytec Co., Ltd., bifunctional, glass transition temperature 14 ° C., 25 ° C. viscosity 12500 mPa · s
Aliphatic urethane acrylate: “EBECRYL230” manufactured by Daicel Cytec Co., Ltd., bifunctional, glass transition temperature of −55 ° C., viscosity at 25 ° C. of 40000 mPa · s
Urethane acrylate: “Aronix M-1200” manufactured by Toagosei Co., Ltd., bifunctional, glass transition temperature 35 ° C., 50 ° C. viscosity 120000-220,000 mPa · s
Acrylic monomer: “PPGDA” manufactured by Toa Gosei Co., Ltd., polypropylene glycol diacrylate, propylene oxide addition mole number about 7 mol, glass transition temperature −8 ° C., 25 ° C. viscosity 30 to 40 mPa · s
Photopolymerization initiator: “Irgacure 184” manufactured by Ciba Japan Co., Ltd.
Acrylic polymerizable composition: “Nopcocure SHC-017R” manufactured by San Nopco Co., Ltd.
Acrylic resin having a polymerizable unsaturated group in the side chain: a compound obtained by adding 3,4-epoxycyclohexenylmethyl acrylate to a part of the carboxyl group of the (meth) acrylic acid- (meth) acrylic acid ester copolymer, “Cyclomer P (ACA) Z321M” manufactured by Daicel Chemical Industries, Ltd., solid content 44% by weight (solvent: 1-methoxy-2-propanol (MMPG) (boiling point 119 ° C.))
Cellulose acetate propionate: trade name “CAP-482-20” manufactured by Eastman, acetylation degree = 2.5%, propionylation degree = 46%, polystyrene conversion number average molecular weight 75,000
Hexafunctional acrylic UV curing monomer: “DPHA” manufactured by Daicel Cytec Co., Ltd.
Trifunctional acrylic UV curing monomer: “PETIA” manufactured by Daicel Cytec Co., Ltd.
Fluorine-containing UV curable compound ("Polyfox 3320" manufactured by Omniva Solution).

[Example 1 of production of cured product by electron beam]
A coating solution containing 20 parts by weight of highly weather-resistant urethane acrylate (EBECRYL8402) and 80 parts by weight of acrylic monomer (PPGDA) was cast on a release film that is silicon-coated on a PET film using wire bar # 55. Thereafter, an electron beam was irradiated in a nitrogen atmosphere under conditions of an acceleration voltage of 200 kV and a dose of 50 kGy to obtain a cured product having a thickness of 100 μm. The obtained hardened | cured material was peeled off from the release film, and the hardened | cured material 1 by an electron beam was obtained.

[Example 2 of production of cured product by electron beam]
A coating solution containing 50 parts by weight of highly weather-resistant urethane acrylate (EBECRYL8402) and 50 parts by weight of aliphatic urethane acrylate (EBECRYL230) is flowed onto a release film that is silicon-coated on a PET film using wire bar # 55. After extending, an electron beam was irradiated in a nitrogen atmosphere under the conditions of an acceleration voltage of 200 kV and a dose of 50 kGy to obtain a cured product having a thickness of 100 μm. The obtained hardened | cured material was peeled from the release film, and the hardened | cured material 2 by an electron beam was obtained.

[Example 3 of production of cured product by electron beam]
On a release film in which a coating liquid containing 100 parts by weight of urethane acrylate (Aronix M-1200) and 30 parts by weight of methyl ethyl ketone (MEK) (boiling point 80 ° C.) is silicon-coated on a PET film using a wire bar # 55 It was cast into. At this stage, because of the high solution viscosity of the coating solution, coating thickness unevenness (bar streaks) due to the wire bar remained on the cast on the base film. The casted product was dried with a drier at 70 ° C., and the state of the coating film after drying was confirmed. However, the bar streaks still remained. Thereafter, an electron beam was irradiated under conditions of an acceleration voltage of 200 kV and a dose of 50 kGy in a nitrogen atmosphere to obtain a cured product having a thickness of 100 μm. The obtained cured product was peeled from the release film to obtain a cured product 3.

[Example 4 of production of cured product by electron beam]
A coating solution containing 100 parts by weight of highly weather-resistant urethane acrylate (EBECRYL8402) and 30 parts by weight of methyl ethyl ketone was cast on a release film which is silicon-coated on a PET film using a wire bar # 55. At this stage, because of the high solution viscosity of the coating solution, coating thickness unevenness (bar streaks) due to the wire bar remained on the cast on the base film. The casted product was dried with a drier at 70 ° C., and the state of the coating film after drying was confirmed. However, the bar streaks still remained. Thereafter, an electron beam was irradiated under conditions of an acceleration voltage of 200 kV and a dose of 50 kGy in a nitrogen atmosphere to obtain a cured product having a thickness of 100 μm. The obtained hardened | cured material was peeled from the release film, and the hardened | cured material 4 by an electron beam was obtained. However, the bar 4 derived from the cast remained in the cured product 4, and a cured product having a uniform coating thickness that was easy to deposit was not obtained.

  The results of evaluating the properties of the cured products 1 to 4 are shown in Table 1.

  As is clear from the results in Table 1, the cured products 1 and 2 have a low tensile elastic modulus and are flexible. In particular, the cured products 1 and 2 and the cured products 3 and 4 are urethanes having similar viscosity. Despite the use of acrylate, cured products 1 and 2 have excellent coating properties and high flexibility.

  Furthermore, the result of having measured the linear expansion coefficient of the hardened | cured material 1 and the hardened | cured material 4 is shown in FIG.3 and FIG.4. As is clear from the results of FIGS. 3 and 4, while the cured product 1 retained a relatively low linear expansion coefficient up to 150 ° C., the cured product 4 behaved as having a melting point near room temperature ( It once contracted and expanded).

[Example 1]
A photopolymerization initiator (Ciba Japan Co., Ltd.) was applied to the coating solution of Production Example 1 of the cured product by the electron beam on a film of a polyester film (“A4300 # 188”, 188 μm manufactured by Toray Industries, Inc.) having an easy adhesion layer. ), “Irgacure 184”) 6 parts by weight were weighed and mixed in a light-shielding bottle. In order to adjust the viscosity, a coating solution in which the temperature of the solution was adjusted to 80 ° C. was applied using a # 14 wire bar, and a cushion layer similar to that in Production Example 1 of the cured product was formed to a thickness of 20 μm, and then ultraviolet rays were formed. A cushion layer was formed by irradiating ultraviolet rays for about 9 seconds using an irradiation apparatus (manufactured by Ushio Electric Co., Ltd., high pressure mercury lamp, ultraviolet ray irradiation amount: 600 mJ / cm ² ).

Next, a solution of 100 parts by weight of an acrylic polymerizable composition (“Nopcocure SHC-017R” manufactured by San Nopco Co., Ltd.) was diluted with MEK on the cushion layer of the film having the cushion layer obtained, and wire bar # 10 and dried by passing through a drying oven at 70 ° C. to form a coat layer having a thickness of about 6 μm. The obtained coating layer was irradiated with ultraviolet rays for about 9 seconds using an ultraviolet irradiation device (manufactured by Ushio Electric Co., Ltd., high-pressure mercury lamp, ultraviolet irradiation amount: 600 mJ / cm ² ). Thus, the film which has a hard-coat layer which is a cushion layer and a 1st functional layer was produced.

  A hard coat layer (second functional layer) was formed in the same manner on the surface opposite to the side on which the hard coat layer (first functional layer) was formed of the obtained laminated film.

About this laminated film, the Martens hardness in the surface of the hard-coat layer which is a 1st functional layer was 27.2 N / mm < ² >, and the maximum indentation depth was 5.52 micrometers. On the other hand, the Martens hardness on the surface of the hard coat layer as the second functional layer was 189.1 N / mm ² and the maximum indentation depth was 2.07 μm.

  Furthermore, an ITO thin film (a transparent conductive layer having a thickness of 30 nm) was formed on the hard coat layer (first functional layer) by sputtering.

  About the obtained transparent conductive laminated film, it bonded together through the spacer of the double-sided tape on the transparent conductive glass substrate with a dot spacer, and created the simple touch panel. As a result of evaluating the keystroke durability of this simple touch panel, the disturbance of the rectangular wave was not observed after the keystroke test of 4.8 million times, and the function of the transparent electrode was maintained. FIGS. 5 to 7 show waveforms (time-voltage) at the start of the key-pressing test, after one million times of key pressing and after 4.8 million times of key pressing, respectively. Furthermore, as a result of evaluating the sliding durability, the linearity (maximum value) after sliding 200,000 times was 0.69%, and the function of the transparent electrode was maintained after sliding 200,000 times.

[Example 2]
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the anti-Newton ring layer was formed by the following method instead of the hard coat layer as the first functional layer.

Acrylic resin having a polymerizable unsaturated group in the side chain (cyclomer P (ACA) Z321M) 15.8 parts by weight, cellulose acetate propionate (CAP-482-20) 1.7 parts by weight, hexafunctional acrylic UV Curing monomer (DPHA) 19.6 parts by weight, trifunctional acrylic UV curing monomer (PETIA) 8.4 parts by weight, fluorine-containing UV curable compound (Polyfox 3320) 0.04 parts by weight, photoinitiator (Irgacure 184) 0 3 parts by weight of methyl ethyl ketone (MEK) (boiling point 80 ° C.) 39.2 parts by weight, 1-butanol (BuOH) (boiling point 113 ° C.) 11.4 parts by weight, and 1-methoxy-2-propanol (MMPG) ( (Boiling point: 119 ° C.) It was dissolved in 3.8 parts by weight of a mixed solvent. This solution was cast on the cushion layer of the obtained film having the hard coat layer and the cushion layer using the wire bar # 28, and then left in an oven at 50 ° C. for 30 seconds to evaporate the solvent. Thus, an anti-Newton ring layer having a thickness of about 12 μm was formed. Thereafter, the coated film was passed through an ultraviolet irradiation device (USHIO INC., High pressure mercury lamp, ultraviolet irradiation amount: 800 mJ / cm ² ) to perform ultraviolet curing treatment.

  About the obtained transparent conductive laminated film, as a result of evaluating the keying durability by the same method as in Example 1, the disturbance of the rectangular wave was not recognized even after 700,000 times of the keying test. FIGS. 8 and 9 show waveforms (time-voltage) at the start of the key-pressing test and after 700,000 times of key-pressing, respectively.

[Example 3]
As the cushion layer, a transparent conductive laminated film was prepared in the same manner as in Example 1 except that a coating solution in which 6 parts by weight of a photopolymerization initiator (Irgacure 184) was blended with the coating solution of Production Example 2 of the cured product by electron beam was used. Manufactured. About the obtained transparent conductive laminated film, the simple touch panel was created by bonding the transparent conductive laminated film on the transparent conductive glass substrate with a dot spacer through the spacer of the double-sided tape. As a result of evaluating the keystroke durability of this simple touch panel, the disturbance of the rectangular wave was not observed after the keystroke test of 4.8 million times, and the function of the transparent electrode was maintained. FIGS. 5 to 7 show waveforms (time-voltage) at the start of the key-pressing test, after one million times of key pressing and after 4.8 million times of key pressing, respectively. Furthermore, as a result of evaluating the sliding durability, the linearity (maximum value) after sliding 200,000 times was 0.69%, and the function of the transparent electrode was maintained after sliding 200,000 times.

[Comparative Example 1]
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the cushion layer was not formed. About the laminated film before forming a transparent conductive layer, the Martens hardness in the surface of the hard-coat layer which is a 2nd functional layer was 198.8 N / mm < ² >, and the maximum indentation depth was 2.03 micrometer. As a result of evaluating the keystroke durability of the transparent conductive laminated film, the rectangular wave was disturbed after one million keystroke tests, and the function of the transparent electrode was impaired. FIG. 10 and FIG. 11 show waveforms (time-voltage) at the time of starting the keying test and after one million times of keying, respectively. Furthermore, as a result of evaluating sliding durability, the linearity (maximum value) was 2.12%, and the function of the transparent electrode was impaired after sliding 100,000 times.

[Comparative Example 2]
A transparent conductive laminated film was produced in the same manner as in Example 2 except that the cushion layer was not formed. As a result of evaluating the keying durability of the transparent conductive laminated film, the rectangular wave was disturbed after 500,000 times of the keying test, and the function of the transparent electrode was impaired after 900,000 times of the keying test. 12 to 14 show waveforms (time-voltage) at the start of the key-pressing test, after 500,000 times of key pressing and after 900,000 times of key pressing, respectively.

[Comparative Example 3]
As the cushion layer, a transparent conductive laminated film was prepared in the same manner as in Example 1 except that a coating solution in which 6 parts by weight of a photopolymerization initiator (Irgacure 184) was blended with the coating solution of Production Example 3 of the cured product by electron beam was used. Manufactured. In addition, as with the film of the cured product 3 by the electron beam, the cushion layer remained uneven in coating thickness (bar streaks), and a uniform coating film was not obtained even after UV curing. About this laminated film, on the transparent conductive glass substrate with a dot spacer, the transparent conductive laminated film was bonded together through the spacer of the double-sided tape, and the simple touch panel was created. As a result of evaluating the keystroke durability of this simple touch panel, the disturbance of the rectangular wave was not seen even after the keystroke test of 1 million times, and the function of the transparent electrode was maintained. Next, as a result of evaluating sliding durability, the linearity (maximum value) after sliding 100,000 times was 0.99%, and the function of the transparent electrode was maintained after sliding 100,000 times. After sliding 200,000 times, the linearity (maximum value) was 2.12%, and the function of the transparent electrode was impaired.

[Comparative Example 4]
As the cushion layer, a transparent conductive laminated film was prepared in the same manner as in Example 1 except that a coating solution in which 6 parts by weight of a photopolymerization initiator (Irgacure 184) was blended with the coating solution of Production Example 4 of a cured product using an electron beam was used. Manufactured. As in the case of Production Example 4 of the cured product, coating layer thickness unevenness (bar streaks) remained in the cushion layer, and a uniform cured product was not obtained even after UV curing.

  As is clear from the results in Table 2, the transparent conductive laminated film of the example was obtained from comparison between Example 1 or 3 and Comparative Example 1, 3 or 4 under the same conditions, and comparison between Example 2 and Comparative Example 2. Has better keystroke durability and / or sliding durability than the transparent conductive film of the comparative example.

  The transparent conductive laminated film of the present invention is used for display devices (liquid crystal display devices, plasma display devices) in display units of electric / electronic or precision devices such as personal computers, televisions, mobile phones, gaming devices, mobile devices, watches, calculators, etc. , Organic or inorganic EL display devices, etc.) can be used for touch panels (particularly resistive film type touch panels). Furthermore, since the transparent electroconductive laminated film of this invention can also form a thick anti-Newton ring layer as a functional layer, it is effective also for a large-screen touch panel.

DESCRIPTION OF SYMBOLS 1 ... White parallel light source 2 ... ND filter 3 ... Sample 4 ... Detector 10 ... Touch panel 11 ... Upper electrode substrate 12 ... Spacer 13 ... Lower electrode substrate 11a, 13a ... Transparent conductive layer 11b ... Anti-Newton ring layer 11c ... Cushion layer 11d, 13d ... Transparent base film 11e, 13e ... Hard coat layer 20 ... Liquid crystal panel

Claims (15)

A transparent conductive laminated film in which a cushion layer, a functional layer, and a transparent conductive layer are sequentially formed in this order on one surface of a base film made of a transparent resin, and the cushion layer is (meth) acrylic A transparent conductive laminated film which is composed of a cured product of a polymerizable composition containing a group, and which has a tensile elastic modulus of 200 MPa or less when the polymerizable composition is measured by the following measurement method.
(Measurement method of tensile modulus)
The tensile modulus of a molded article having a thickness of 100 μm obtained by curing a polymerizable composition containing a (meth) acrylic group with an electron beam having an acceleration voltage of 200 kV and an irradiation dose of 50 kGy is measured.   The transparent conductive laminated film according to claim 1, wherein the polymerizable composition contains urethane (meth) acrylate. The transparent conductive laminated film according to claim 2, wherein the polymerizable composition further contains poly C _3-4 alkylene glycol di (meth) acrylate. Poly _{C 3-4} alkylene glycol di (meth) acrylate has an average repetition number of oxy _{C 3-4} alkylene unit comprises a poly _{C 3-4} alkylene glycol di (meth) acrylate is 5 to 9 moles, and urethane ( The transparent conductive laminated film according to claim 3, wherein a ratio (weight ratio) of the (meth) acrylate to the poly C _3-4 alkylene glycol di (meth) acrylate is the former / the latter = 30/70 to 10/90.   The thickness of a cushion layer is over 10 micrometers, and the thickness ratio of a base film and a cushion layer is base film / cushion layer = 20/1-5/1. Transparent conductive laminated film.   The transparent conductive laminated film according to claim 1, wherein the polymerizable composition is a composition having a tensile modulus of 1 to 100 MPa when measured by the method according to claim 1.   The transparent conductive laminated film according to claim 1, wherein the polymerizable composition contains substantially no solvent.   The transparent conductive laminated film according to any one of claims 1 to 7, wherein the cushion layer has a glass transition temperature of -30 ° C to 30 ° C, a tensile elastic modulus of 50 MPa or less, and a total light transmittance of 92% or more. The transparent conductive laminated film according to claim 1, wherein the Martens hardness on the surface of the functional layer from which the transparent conductive layer has been peeled is 100 N / mm ² or less and the maximum indentation depth is 3 μm or more.   The transparent conductive laminated film according to claim 1, wherein the cured product of the polymerizable composition is a cured product by active energy rays.   The transparent conductive laminated film according to claim 1, wherein the functional layer is a hard coat layer or an anti-Newton ring layer.   The functional layer is an anti-Newton ring layer including a phase separation structure including one or more polymers and one or more cured curable resin precursors and having an uneven shape on the surface. The transparent electroconductive laminated film in any one of -11.   The transparent conductive laminated film according to any one of claims 1 to 12, which is a transparent electrode substrate of a resistive film type touch panel, and the transparent electrode substrate is an upper electrode substrate on a side in contact with a finger or a pressing member.   A transparent conductive laminated film in which a cushion layer, a functional layer, and a transparent conductive layer are sequentially formed in this order on one surface of a base film made of a transparent resin, and the cushion layer is (meth) acrylic A transparent conductive laminated film comprising a cured product of a polymerizable composition containing a group and having a thickness of greater than 10 μm.   A resistive touch panel comprising the transparent conductive laminated film according to claim 1 as an upper electrode substrate.

Images