JP5410698B2 - Transparent conductive polyester film composite and touch panel electrode - Google Patents

Description

  The present invention relates to a transparent conductive polyester film composite. Specifically, a transparent conductive polyester film composite having an adhesive layer excellent in sticking property, removability, pen sliding durability, etc. and excellent in heat-resistant water adhesion between the adhesive layer and the substrate film Further, the present invention also relates to an electrode for a touch panel using the transparent conductive polyester film composite.

  The touch panel is recognized as an excellent input method, and is used in various fields such as bank ATMs, ticket vending machines, personal digital assistants, game machines, car navigation systems, and the like. A transparent electrode is required for a touch panel, and glass has conventionally been used for a substrate. Recently, however, many transparent conductive films having a transparent conductive layer provided on a plastic film surface have been proposed.

  For example, when used as an upper electrode, the transparent conductive film requires a conductive layer to be an electrode, a base material that supports the conductive layer, and a hard coat layer that can withstand friction when inputting by hand or a dedicated pen. It is. For example, Patent Document 1 discloses a transparent conductive film in which a plastic film, a cured product layer, and a transparent conductive thin film are laminated. In this document, a transparent film and a film serving as an input surface (hard coat layer) are disclosed. A conductive film is bonded through an adhesive and used as an electrode for a touch panel. Patent Document 2 discloses a laminate in which a plastic film provided with a hard coat layer and a transparent conductive film having a transparent conductive thin film are bonded together via a transparent adhesive layer.

  Thus, when each layer required as an electrode for touch panels is laminated, an adhesive layer is often required. Since many members for touch panels are expensive, an adhesive layer excellent in removability that can be peeled off when a sticking mistake occurs during bonding and fixing with the adhesive layer and can be attached again is desirable. It is also known that if a pressure-sensitive adhesive layer with cushioning properties is used, durability against repeated pressing (pen sliding durability) on the touch panel is improved.

  For these reasons, it is conceivable to use silicone rubber as an adhesive for touch panel members. However, it cannot be said that silicone rubber and a plastic film such as polyethylene terephthalate have sufficient adhesion. When the adhesiveness between the adhesive layer and the transparent conductive film substrate is inferior, there is a problem in that peeling occurs at the joint portion and no current is applied even when touched. Further, when the touch panel is used for car navigation or the like, the environment inside the vehicle may be considerably hot and humid, but it is necessary to withstand such severe use conditions.

  On the other hand, the present inventors have proposed a rubber film composite in which a rubber layer is directly bonded to a polyester film as a base material without using an adhesive in Patent Documents 3 to 5 and the like, and a method for producing the same. . In these techniques, it is described that it is preferable to use a film subjected to easy adhesion treatment as a polyester film. However, the rubber film composite obtained by the above method is inferior in the durability of adhesion between the polyester film and the silicone rubber layer, and when used under the above severe conditions, the polyester film and the silicone rubber layer are There was a problem that it might peel off.

Furthermore, the transparent conductive film having an adhesive layer is usually shipped in a form in which a separate film is laminated on the surface of the adhesive layer in order to improve the handleability. When actually used, the separate film is peeled off and attached to the target article. However, depending on the application, there is a strong demand for reducing the peeling force. However, if the peel strength of the separate film is too small, when the sheet is wound in the production process of the adhesive sheet, partial separation of the separate film occurs, and an air layer enters in a direction perpendicular to the sheet winding direction. The so-called channeling phenomenon may occur.
JP 2007-59360 A JP 2007-234424 A JP 10-53659 A Japanese Patent Laid-Open No. 10-58605 Japanese Patent Laid-Open No. 10-95071

  In the present invention, in view of the above circumstances, a transparent conductive polyester film composite having a transparent conductive layer and a cushioning pressure-sensitive adhesive layer, and having excellent adhesion between the pressure-sensitive adhesive layer and the base film, particularly excellent heat-resistant water adhesion. The issue was to provide.

  The transparent conductive polyester film composite of the present invention that has solved the above problems is at least a transparent conductive layer (A), a polyester base film (B), an adhesion improving layer (C), and a silicone rubber pressure-sensitive adhesive layer (D). The release layer (E) and the polyester film (F) are transparent conductive polyester film composites laminated in this order, and the pressure-sensitive adhesive layer (D) measured by the method defined in the specification and the above The main point is that the peel strength with the release layer (E) is 0.03 to 1.0 N / 20 mm.

  The transparent conductive polyester film composite is preferably such that the adhesive layer (D) does not peel off when the hot water adhesion is evaluated by the method defined in the specification.

  The release layer (E) is preferably made of a non-silicone compound, and more preferably a layer containing a binder resin, a polymer wax component and an antistatic agent.

  It is preferable that the said adhesive improvement layer (C) is provided also between the transparent conductive layer (A) and the polyester-type base film (B). In any case, the adhesion improving layer (C) preferably has a thickness of 0.01 to 0.5 μm and contains a crosslinked polymer. In addition, the adhesion improving layer (C) is an embodiment containing a reaction product of at least one polymer selected from the group consisting of polyester, polyurethane and acrylic polymer and a crosslinking agent, self-crosslinking polyester, polyurethane And an embodiment including one in which one or more self-crosslinking polymers selected from the group consisting of acrylic polymers are self-crosslinked are preferred embodiments.

  The adhesive layer (D) preferably contains a crosslinked silicone compound having a polydimethylsiloxane skeleton. In this case, the crosslinked silicone compound is a polydimethylsiloxane having a number average molecular weight of 50,000 to 500,000. It is preferable to crosslink an uncrosslinked product of a silicone compound having a skeleton. In particular, a composition obtained by crosslinking a composition comprising an uncrosslinked silicone compound having a polydimethylsiloxane skeleton having a number average molecular weight of 50,000 to 500,000 and a (meth) acrylic acid ester of a polyhydric alcohol as an adhesion improver. It is preferable that

  The transparent conductive polyester film composite of the present invention is preferably used as a touch panel member, and after the release layer (E) and the polyester film (F) have been peeled off, the transparent base material is subjected to hard processing. More preferably, it is used as an upper electrode of a touch panel.

  In the present invention, the release layer (E) and the polyester film (F) are peeled off from the transparent conductive polyester film composite of the present invention and attached to a transparent base material subjected to hard processing. The upper electrode for touch panels provided with the obtained laminated body is also included.

  When the transparent conductive polyester film composite of the present invention includes a transparent conductive layer and a silicone rubber pressure-sensitive adhesive layer having both sticking property and removability, it is used as, for example, a member of a touch panel. When there is a sticking mistake, etc., the composite can be easily removed and can be pasted again. In addition, since the silicone rubber pressure-sensitive adhesive layer has good elasticity, the touch panel can be given good cushioning properties, so that the pen sliding durability of the touch panel can be improved.

  Furthermore, since the transparent conductive polyester film composite of the present invention is provided with an adhesion improving layer between the pressure-sensitive adhesive layer and the base polyester film, it has excellent adhesion durability and is used under severe conditions. Also in some cases, it can be suitably used. In addition, the peel strength of the separate film laminated on the surface of the silicone rubber adhesive layer is controlled to an appropriate range, and the occurrence of the above-mentioned channeling phenomenon is suppressed in the process of winding the transparent conductive polyester film composite. Therefore, a high quality transparent conductive polyester film composite can be stably produced. Moreover, it is excellent also in workability | operativity at the time of incorporating a transparent conductive polyester film composite body in a touch panel.

  Therefore, it became possible to provide a high-performance touch panel by using the transparent conductive polyester film composite of the present invention.

  The transparent conductive polyester film composite of the present invention comprises at least a transparent conductive layer (A), a polyester base film (B), an adhesion improving layer (C), a silicone rubber adhesive layer (D), a release layer ( E) and a polyester film (F) are laminated in this order, and as described later, the peel strength between the release layer (E) and the adhesive layer (D) is controlled within a specific range. doing. Hereinafter, each layer will be described.

[Transparent conductive layer (A)]
Typical transparent conductive materials include metals such as gold, silver and copper; metal oxides such as indium oxide, tin oxide and zinc oxide or composite oxides thereof; polyaniline, polyacetylene, polythiophene, polyparaphenylene, Examples thereof include conductive polymers such as polyparaphenylene vinylene and polypyrrole. Of these, metal oxides such as indium oxide, tin oxide, and zinc oxide, or composite oxides thereof are preferable. For these, one or more dopants may be used from tin oxide, zinc oxide, antimony oxide, tungsten oxide, zirconium oxide, silicon oxide, and the like. The content of the dopant is preferably in the range of 0.1 to 50 mass% with respect to the metal oxide or composite oxide. If the content is less than 0.1% by mass, the function as a dopant cannot be sufficiently exhibited, and if the content exceeds 50% by mass, the original characteristics of the metal oxide and composite oxide are impaired, which is not preferable. .

  When manufacturing a transparent conductive layer (A) from the said conductive polymer, what is necessary is just to dissolve in a suitable solvent and to use a well-known coating method.

  In order to form the transparent conductive layer (A) using the metals, metal oxides, and composite oxides, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, or the like can be employed. For example, in the case of the sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen, water vapor or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, or ion assist may be used in combination. In addition, a bias such as direct current, alternating current, and high frequency may be applied to the substrate as long as the object of the present invention is not impaired.

  Moreover, it is preferable that the temperature at the time of forming a transparent conductive layer (A) on a polyester-type base film (B) shall be 150 degrees C or less. In order to set the temperature at the time of film formation to a temperature exceeding 150 ° C., the film feed rate must be extremely slow, which is not preferable from the viewpoint of productivity.

  Moreover, it is preferable to perform the vacuum degree at the time of performing sputtering in the range of 0.01-10Pa. When the degree of vacuum is higher than 0.01 Pa, since stable discharge cannot be performed, sputtering is not stable. Moreover, even if the degree of vacuum is lower than 10 Pa, since stable discharge cannot be performed, sputtering is not stable. The same applies to other methods such as vapor deposition and CVD.

  The thickness of the transparent conductive layer (A) is preferably in the range of 4 to 800 nm, particularly preferably 5 to 500 nm. When the thickness of the transparent conductive layer (A) is thinner than 4 nm, it is difficult to form a continuous thin film, and it is difficult to show good conductivity. On the other hand, when the thickness is larger than 800 nm, the transparency tends to decrease, which is not preferable.

[Polyester base film (B), polyester film (F)]
The polyester base film (B) and the polyester film (F) can be arbitrarily used as long as they have polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate or the like as a main component (80% by mass or more). A biaxially stretched one is desirably used. The production method of the biaxially stretched polyester film is not particularly limited. For example, after drying the polyester as necessary, it is supplied to a known melt extruder, extruded from a slit-shaped die into a sheet, electrostatic application, etc. In this manner, the unstretched sheet may be stretched after being brought into close contact with the casting drum, cooled and solidified to obtain an unstretched sheet. The biaxial stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching.

  Although the thickness of a polyester-type base film (B) is not specifically limited, About 10-300 micrometers is preferable, More preferably, it is 70-260 micrometers. If the film thickness is less than 10 μm, the mechanical strength is insufficient and handling becomes difficult, which is not preferable. On the other hand, if the thickness exceeds 300 μm, it is too thick for use as a touch panel member and is not suitable for mobile devices. In the case of the polyester film (F), the thickness is preferably about 10 to 150 μm. More preferably, it is 15-75 micrometers. If the film thickness is less than 10 μm, the mechanical strength is insufficient and handling becomes difficult, which is not preferable. On the other hand, when the thickness exceeds 150 μm, the strength is sufficient and uneconomical, and the handling property when peeling the film may be lowered.

  The polyester base film (B) may be subjected to known surface treatments such as corona treatment, flame treatment, plasma treatment and the like. Adhesion with the transparent conductive layer (A) and the adhesion improving layer (C) is improved.

[Adhesion improvement layer (C)]
In the transparent conductive polyester film composite of the present invention, an adhesion improving layer (C) is provided between the polyester base film (B) and the adhesive layer (D). In the evaluation of hot water adhesiveness described later, the pressure-sensitive adhesive layer (D) is a layer that does not peel from the polyester base film (B). The thickness of the adhesion improving layer (C) is preferably 0.01 to 0.5 μm. If the thickness of the adhesion improving layer (C) is 0.01 to 0.5 μm, good hot water adhesion is exhibited. However, if the thickness is outside the above range, the hot water adhesion may not be good, which is not preferable. A more preferable thickness range is 0.03 to 0.4 μm, and 0.05 to 0.3 μm is even more preferable.

  The adhesive improvement layer (C) is preferably a crosslinked polymer layer (crosslinked polymer layer), which may be a layer obtained by crosslinking a polymer with a crosslinking agent or a layer using a self-crosslinking type polymer. .

  The polymer that can be used in the method of crosslinking with a crosslinking agent is not particularly limited, but is preferably at least one selected from the group consisting of polyesters, polyurethanes, and acrylic polymers. The above polymers may be used alone or in combination of two or three different types.

[Polyester for Adhesion Improvement Layer (C)]
The polyester has an ester bond in the main chain or side chain, and is obtained by polycondensation of polyvalent carboxylic acid and glycol.

  As the polyvalent carboxylic acid component constituting the polyester, aromatic, aliphatic, and alicyclic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, and ester derivatives thereof can be used.

  Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxy Ethane-p, p′-dicarboxylic acid, phenylindanedicarboxylic acid and the like can be used. From the viewpoint of the strength and heat resistance of the adhesion improving layer (C), these aromatic dicarboxylic acids are preferably at least 30 mol%, more preferably at least 35 mol%, even more preferably at 100 mol% of the polyvalent carboxylic acid component. Is preferably a polyester occupying 40 mol% or more.

  Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used.

  Examples of the glycol component of polyester include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol Neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2, 4-trimethyl-1,6-hexanediol, 1,2-cyclo Xanthodimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodiphenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4′-isopropylidenephenol 4,4′-isopropylidenediol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and the like can be used.

  In addition, when using polyester as an aqueous liquid as a coating liquid, a compound containing a carboxylic acid (salt) group or a compound containing a sulfonic acid (salt) group is used to facilitate water-solubilization or water-dispersion of the polyester It is preferable to copolymerize a compound containing a phosphonic acid (salt) group.

  Examples of the compound containing a carboxylic acid (salt) group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1 , 2,3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydro Furfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellite 2,2 ′, 3,3′-diphenyltetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, ethylenetetracarboxylic acid, etc., or alkali metal salts, alkaline earth metal salts thereof, An ammonium salt etc. can be mentioned.

  Examples of the compound containing a sulfonic acid (salt) group include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, sulfo-p-xylylene glycol, 2-sulfo-1,4-bis (hydroxyethoxy) benzene or the like, or an alkali metal salt, alkaline earth metal salt, or ammonium salt thereof can be used.

  Examples of the compound containing a phosphonic acid (salt) group include phosphoterephthalic acid, 5-phosphoisophthalic acid, 4-phosphoisophthalic acid, 4-phosphonaphthalene-2,7-dicarboxylic acid, phospho-p-xylylene glycol, 2-phospho-1,4-bis (hydroxyethoxy) benzene or the like, or an alkali metal salt, alkaline earth metal salt, or ammonium salt thereof can be used.

  In the present invention, for example, a modified polyester copolymer such as a block copolymer or a graft copolymer modified with acrylic, urethane, epoxy, or the like can be used as the polyester.

  Preferred polyesters include those selected from terephthalic acid, isophthalic acid, sebacic acid, 5-sodium sulfoisophthalic acid as the acid component, and ethylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol as the glycol component. And the like. When water resistance is required, a copolymer or the like containing trimellitic acid as its copolymer component can be suitably used instead of 5-sodium sulfoisophthalic acid.

  The polyester can be produced by the following production method. For example, a polyester having a dicarboxylic acid component consisting of terephthalic acid, isophthalic acid, and 5-sodium sulfoisophthalic acid and a glycol component consisting of ethylene glycol and neopentyl glycol can be directly esterified with these monomers. Or it can manufacture by the method etc. which manufacture by the 1st step which transesterifies, and the 2nd step which carries out the polycondensation reaction of the reaction product of this 1st step.

  At this time, for example, alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, titanium compound, or the like can be used as the reaction catalyst.

  Further, as a method for obtaining a polyester having many carboxyl groups at the terminal and / or side chain, JP-A-54-46294, JP-A-60-209073, JP-A-62-240318, JP JP 53-26828, JP 53-26829, JP 53-98336, JP 56-116718, JP 61-124684, JP 62-240318 Although it can be produced by copolymerizing a trivalent or higher polyvalent carboxylic acid described in the gazette, etc., other methods may be used.

  Further, as the water-dispersed polyester resin, for example, a commercially available “Vaironal (registered trademark)” series (manufactured by Toyobo Co., Ltd.) can be used.

  The intrinsic viscosity of the polyester is not particularly limited, but is preferably 0.3 dl / g or more in terms of adhesiveness, more preferably 0.35 dl / g or more, and most preferably 0.4 dl / g or more. It is. The glass transition temperature (hereinafter sometimes abbreviated as Tg) of the polyester is preferably 0 to 130 ° C, more preferably 10 to 85 ° C. The use of polyester having a Tg of 0 ° C. or higher improves the resistance to hot water, and after laminating the adhesion improving layer (C) on the surface of the polyester-based substrate film (B) The blocking phenomenon can be suppressed. Moreover, stability and water dispersibility can be favorably maintained by using polyester with Tg of 130 ° C. or lower.

[Polyurethane for adhesive improvement layer (C)]
Next, polyurethane will be described. The polyurethane is not particularly limited as long as it has a urethane bond, and the main component is obtained by polymerizing a polyol compound and a polyisocyanate compound.

  Examples of the polyol compound include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexamethylene. Adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin, acrylic polyol and the like can be used.

  Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, an adduct of hexamethylene diisocyanate and trimethylolethane, and the like. it can.

  In the synthesis of the polyurethane, a known chain extender, a crosslinking agent, and the like may be included in addition to the polyol compound and the polyisocyanate compound. As the chain extender or crosslinking agent, ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine, or the like can be used.

  In order to obtain a stable polyurethane water dispersion, it is preferable to synthesize polyurethane having an increased affinity for water. Specifically, an appropriate amount of anionic groups may be introduced into the polyurethane. For example, a method of using a compound having an anionic group for polyol, polyisocyanate, chain extender, etc., a method of reacting an unreacted isocyanate group of the produced polyurethane with a compound having an anionic group, or having an active hydrogen of polyurethane It can be produced by a method of reacting a group with a specific compound.

  The anionic group in the polyurethane is preferably used as a sulfonic acid group, a carboxylic acid group, and an ammonium salt, lithium salt, sodium salt, potassium salt or magnesium salt thereof.

  The amount of the unit having an anionic group in the polyurethane is preferably 0.05% by mass to 15% by mass from the viewpoint of water dispersibility of the polyurethane.

  For example, as a polyurethane water dispersion, “Hydran (registered trademark)” series (manufactured by Dainippon Ink & Chemicals, Inc.) can be used.

[Acrylic polymer for adhesive improvement layer (C)]
Examples of the monomer component constituting the acrylic polymer include, for example, alkyl acrylate, alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. Hydroxy group-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate), 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.) ; (Meth) acrylamide N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-phenyl (meth) acrylamide, etc. Amino group-containing monomer such as N, N-diethylaminoethyl (meth) acrylate; epoxy group-containing monomer such as glycidyl (meth) acrylate; (meth) acrylic acid and salts thereof (lithium salt, sodium salt, A monomer containing a carboxyl group such as potassium salt or the like or a salt thereof can be used, and these are (co) polymerized using one kind or two or more kinds. Furthermore, these can be used in combination with other types of monomers.

  Examples of other types of monomers include epoxy group-containing monomers such as allyl glycidyl ether; sulfonic acids such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomer containing a group and a salt thereof; a monomer containing a carboxyl group or a salt thereof such as crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomers containing acid anhydrides such as maleic anhydride and itaconic anhydride; vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid monoester, alkyl fumaric acid monoe Ether, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, may be used vinyl chloride.

  Moreover, as said acrylic polymer, a modified acrylic polymer, for example, a block copolymer modified with polyester, polyurethane, epoxy resin, etc., a graft copolymer, etc. can be used.

  The lower limit of the acrylic polymer Tg is preferably −10 ° C. from the viewpoints of heat resistant water adhesion and blocking resistance, more preferably the lower limit is 0 ° C., and the most preferable lower limit is 10 ° C. On the other hand, the Tg of the acrylic polymer is preferably 90 ° C. from the viewpoint of heat resistant water adhesion and film-forming property, more preferably 50 ° C., and most preferably 40 ° C. Further, the weight average molecular weight (Mw) of the acrylic polymer is preferably 50,000 or more, and more preferably 300,000 or more from the viewpoint of heat resistant water adhesion.

  Preferable examples of the acrylic polymer include copolymers composed of monomers selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, and acrylic acid.

  It is preferable to dissolve, emulsify, or suspend an acrylic polymer in water and use it as an aqueous liquid from the viewpoint of environmental pollution and explosion-proof properties during coating. Such water-based acrylic polymers are copolymerized with monomers having a hydrophilic group (acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and salts thereof, etc.) and emulsion polymerization using reactive emulsifiers and surfactants, It can be prepared by a method such as suspension polymerization or soap-free polymerization.

  Commercially available acrylic emulsions may also be used, for example, “Jonkrill (registered trademark)” series (manufactured by BASF Japan).

[Crosslinking agent used for adhesion improving layer (C)]
In the present invention, the polyester, polyurethane and acrylic polymer are preferably crosslinked. When the above polymer is cross-linked using a cross-linking agent, the cross-linking agent may be any one that can cross-link with a functional group present in the above-described polymer, such as a carboxyl group, a hydroxyl group, a methylol group, an amide group, or the like. . For example, melamine crosslinking agent, oxazoline crosslinking agent, isocyanate crosslinking agent, aziridine crosslinking agent, epoxy crosslinking agent, methylolated or alkylolized urea, acrylamide, polyamide resin, amide epoxy compound, various silanes A coupling agent, various titanate coupling agents, etc. can be used. In particular, a melamine-based crosslinking agent and an oxazoline-based crosslinking agent can be suitably used from the viewpoints of compatibility with the above-described polymer, heat resistant water adhesion, and the like.

  The melamine-based crosslinking agent is not particularly limited, but is a melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a methylolated melamine with a lower alcohol, or these A mixture of the above can be used. Moreover, as a melamine type crosslinking agent, a monomer, the condensate which consists of a multimer more than a dimer, these mixtures, etc. can be used. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. Methylolated melamine resins such as methylated trimethylolmelamine and butylated hexamethylolmelamine are preferred. Furthermore, in order to accelerate | stimulate the thermosetting of a melamine type crosslinking agent, you may use acidic catalysts, such as p-toluenesulfonic acid, for example.

  Further, the oxazoline-based crosslinking agent is not particularly limited as long as it has an oxazoline group as a functional group in the compound, but includes at least one monomer containing an oxazoline group, and at least one kind of What consists of an oxazoline group containing copolymer obtained by copolymerizing another monomer is preferable.

  Monomers containing an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be used, and one or a mixture of two or more thereof can also be used. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

  In the oxazoline group-containing copolymer, the at least one other monomer used together with the oxazoline group-containing monomer is not particularly limited as long as it is a monomer copolymerizable with the oxazoline group-containing monomer. (Meth) acrylates or methacrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; non-acrylic acid, methacrylic acid, itaconic acid, maleic acid, etc. Saturated carboxylic acids; unsaturated nitriles such as (meth) acrylonitrile; unsaturated amides such as (meth) acrylamide and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; methyl vinyl ether and ethyl Vinyl ethers such as nyl ether; olefins such as ethylene and propylene; halogen-containing α-β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α, β-unsaturated such as styrene and α-methylstyrene Saturated aromatic monomers etc. can be used and these can use 1 type, or 2 or more types of mixtures.

  As the oxazoline group-containing polymer, for example, “Epocross (registered trademark)” series (manufactured by Nippon Shokubai Co., Ltd.) is available.

  The isocyanate-based crosslinking agent is not particularly limited as long as it has an isocyanate group as a functional group in the compound, but it is preferable to use a polyfunctional isocyanate compound containing two or more isocyanate groups in one molecule. .

  As the polyfunctional isocyanate compound, a low-molecular or high-molecular aromatic or aliphatic diisocyanate or a trivalent or higher polyisocyanate can be used. Examples of the polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. Furthermore, an excess amount of these isocyanate compounds and low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, or polyester polyols, poly The terminal isocyanate group containing compound obtained by making it react with polymer active hydrogen compounds, such as ether polyols and polyamides, can be mentioned.

  In addition, when using an isocyanate compound as a crosslinking agent, it is also possible to use a blocked isocyanate compound. The blocked isocyanate can be prepared by subjecting the above isocyanate compound and blocking agent to an addition reaction by a conventionally known appropriate method. Examples of the isocyanate blocking agent include phenols such as phenol, cresol, xylenol, resorcinol, nitrophenol and chlorophenol; thiophenols such as thiophenol and methylthiophenol; oximes such as acetoxime, methylethylketoxime and cyclohexanone oxime; Alcohols such as methanol, ethanol, propanol and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol; -Lactams such as caprolactam, δ-valerolactam, γ-butyrolactam, β-propyllactam; aromatic amines; imides; acetylacetone, acetoacetate, malonic acid Active methylene compounds such as glycol ester; mercaptans; imines; ureas; diaryl compounds; can be mentioned sodium bisulfite and the like.

  The epoxy-based crosslinking agent is not particularly limited as long as it has an epoxy group as a functional group in the compound. However, it is preferable to use a polyfunctional epoxy compound having two or more epoxy groups in one molecule. .

  Examples of the polyfunctional epoxy compound include diglycidyl ether of bisphenol A and oligomer thereof, diglycidyl ether of hydrogenated bisphenol A and oligomer thereof, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene Glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and Polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl Examples include ether, triglycidyl ether of glycerol alkylene oxide adduct, and the like.

  As the cross-linking agent, a phenol formaldehyde resin of a condensate with formaldehyde such as alkylated phenols and cresols; an adduct of urea, melamine, benzoguanamine and the like with formaldehyde, this adduct and an alcohol having 1 to 6 carbon atoms An amino resin such as an alkyl ether compound consisting of can also be used.

  Examples of the phenol formaldehyde resin include alkylated (methyl, ethyl, propyl, isopropyl or butyl) phenol, p-tert-amylphenol, 4,4′-sec-butylidenephenol, p-tert-butylphenol, o-, m-, p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl-o-cresol, p-phenylphenol, xylenol, etc. And the condensates of phenols and formaldehyde.

  Examples of amino resins include methoxylated methylol urea, methoxylated methylol N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, and the like. Are preferably methoxylated methylol melamine, butoxylated methylol melamine, methylolated benzoguanamine, and the like.

  The polymer (polyester, polyurethane, acrylic polymer) and the crosslinking agent can be mixed and used in an arbitrary ratio. However, in order to express the hot water adhesive effect of the present invention more remarkably, the crosslinking agent is: The addition of 2 to 50 parts by mass with respect to 100 parts by mass of the polymer is preferred, more preferably 3 to 25 parts by mass. When the addition amount of the crosslinking agent is less than 2 parts by mass, the effect of addition is small, and when it exceeds 50 parts by mass, the hot water resistant adhesiveness tends to be lowered.

[Self-crosslinking polymer of adhesion improving layer (C)]
In the present invention, in addition to the above method, for example, the adhesion improving layer (C) may be formed using a self-crosslinking type polymer in which a crosslinkable functional group is introduced into the above-described polymer. In the case of using a self-crosslinking type polymer, the crosslinking method may be, for example, thermal crosslinking, or may be crosslinking with high energy active rays such as ultraviolet rays, electron beams and γ rays.

  Hereinafter, a specific method will be illustrated for the case of polyester as the self-crosslinking polymer.

  The self-crosslinking type polyester preferably used in the present invention is a polyester graft copolymer obtained by grafting a hydrophobic copolymer polyester with a compound having at least one radical polymerizable double bond. The “grafting” of the polyester-based graft copolymer in the present invention is to introduce a branched polymer made of a polymer different from the main chain into the backbone polymer which is the main chain. Graft polymerization is usually carried out by reacting at least one radically polymerizable monomer using a radical initiator in a state where a hydrophobic copolyester is dissolved in an organic solvent. Hydrophobic copolyesters are essentially water-insoluble polyesters that do not inherently dissolve in water, so they are more heat resistant than using polyester resins that are soluble in water as the backbone polymer for graft polymerization. Excellent water adhesion.

  The hydrophobic copolyester is composed of 60 to 99.5 mol% of aromatic dicarboxylic acid, 0 to 39.5 mol% of aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid in 100 mol% of dicarboxylic acid component, radical It is preferable that the dicarboxylic acid containing a polymerizable double bond is 0.5 to 10 mol%. More preferably, the aromatic dicarboxylic acid is 68 to 98 mol%, the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid is 0 to 30 mol%, and the dicarboxylic acid containing a polymerizable unsaturated double bond is 2 to 7 Mol%.

  When the aromatic dicarboxylic acid is 60 mol% or more and the aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid is 39.5 mol% or less, the heat resistant water adhesion is good. Moreover, the grafting of the radically polymerizable monomer with respect to the polyester resin can be efficiently performed by using 0.5 mol% or more of the dicarboxylic acid containing a radically polymerizable double bond. On the other hand, the content of 10 mol% or less is preferable because the viscosity of the reaction solution can be prevented from significantly increasing in the later stage of the grafting reaction, and the reaction can proceed uniformly.

  As the aromatic dicarboxylic acid, aliphatic and / or alicyclic dicarboxylic acid, any of the compounds exemplified above can be used. Examples of the dicarboxylic acid containing a radically polymerizable double bond include fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, and other α, β-unsaturated dicarboxylic acids; 2,5-norbornene dicarboxylic acid anhydride And alicyclic dicarboxylic acids containing unsaturated double bonds such as tetrahydrophthalic anhydride. Of these dicarboxylic acids containing a polymerizable unsaturated double bond, fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid are preferred from the viewpoint of polymerizability.

  As the glycol component, any of the compounds exemplified above can be used. Two or more glycol components may be used in combination. Especially, C2-C10 aliphatic glycol, C6-C12 alicyclic glycol, etc. are preferable.

  The hydrophobic copolymerized polyester may be copolymerized with 0 to 5 mol% of a trifunctional or higher polycarboxylic acid and / or polyol. The tri- or higher functional polycarboxylic acid includes (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) benzophenone tetracarboxylic acid, trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (anne) Hydrotrimellitate) and the like. As the trifunctional or higher functional polyol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, or the like is used.

  The tri- or higher functional polycarboxylic acid and / or polyol is copolymerized in the range of 0 to 5 mol%, preferably 0 to 3 mol%, based on the total acid component or the total glycol component. Gelation can be suppressed.

  In addition, the lower limit of the weight average molecular weight of the hydrophobic copolyester is preferably 5,000 from the viewpoint of heat resistant water adhesion. Moreover, it is preferable that an upper limit is 50,000 at points, such as gelatinization at the time of superposition | polymerization.

  After the hydrophobic copolyester is synthesized, graft polymerization is performed. Graft polymerization is performed by reacting at least one radical polymerizable monomer using a radical initiator in a state where the hydrophobic copolyester is dissolved in an organic solvent. The reaction product after completion of the grafting reaction is not limited to the graft copolymer of the desired hydrophobic copolymerized polyester and the radically polymerizable monomer, but also the hydrophobic copolymerized polyester and the hydrophobic copolymer that were not subjected to grafting. It also contains a (co) polymer obtained from a radically polymerizable monomer that has not been grafted to the polyester. The polyester-based graft copolymer in the present invention includes not only the above-described polyester-based graft copolymer, but also a hydrophobic copolymerized polyester that has not been grafted, and a radically polymerizable monomer that has not been grafted. Also included are reaction mixtures containing the resulting (co) polymer and monomer (residual monomer).

In the present invention, the acid value of a reaction product obtained by graft polymerization of a radically polymerizable monomer to a hydrophobic copolymerized polyester is preferably 600 eq / 10 ⁶ g or more from the viewpoint of heat resistant water adhesion. More preferably, the acid value of the reactant is 1200 eq / 10 ⁶ g or more. When the acid value of the reaction product is less than 600 eq / 10 ⁶ g, the hot water adhesion may be lowered.

  The mass ratio of the desired hydrophobic copolymerized polyester and the radical polymerizable monomer suitable for the purpose of the present invention is preferably in the range of polyester / radical polymerizable monomer = 40/60 to 95/5, more preferably 55/45. ~ 93/7, most desirably in the range of 60/40 to 90/10.

  By setting the mass ratio of the hydrophobic copolyester to 40% by mass or more, the excellent adhesiveness of the polyester can be exhibited. On the other hand, when the mass ratio of the hydrophobic copolymerized polyester is 95% by mass or less, the blocking resistance can be improved and the acid value of the reaction product can be adjusted to the above range.

  The graft polymerization reaction product is in the form of an organic solvent solution or dispersion or an aqueous solvent solution or dispersion. In particular, a dispersion of an aqueous solvent, that is, a form of an aqueous dispersion is preferable in terms of working environment and applicability. Therefore, as the radical polymerizable monomer to be grafted, it is preferable to use a radical polymerizable monomer that essentially contains a hydrophilic radical polymerizable monomer. And after carrying out the graft polymerization in an organic solvent, the aqueous dispersion can be obtained by distilling off the organic solvent and adding water.

  The hydrophilic radical polymerizable monomer means a radical polymerizable monomer having a hydrophilic group or a group that can be changed to a hydrophilic group later. Examples of the radical polymerizable monomer having a hydrophilic group include a radical polymerizable monomer containing a carboxyl group, hydroxyl group, phosphoric acid group, phosphorous acid group, sulfonic acid group, amide group, quaternary ammonium base and the like. . On the other hand, examples of the radical polymerizable monomer having a group that can be changed into a hydrophilic group include radical polymerizable monomers containing an acid anhydride group, a glycidyl group, a chloro group, and the like. Among these, from the viewpoint of water dispersibility, a carboxyl group is preferable, and a radical polymerizable monomer having a carboxyl group or a group capable of generating a carboxyl group is preferable.

  In order to make the acid value of the graft reaction product within the above preferred range, it is preferable that a radical polymerizable monomer containing a carboxyl group or having a group capable of generating a carboxyl group is contained. Such monomers include fumaric acid, monoethyl fumarate; maleic acid and its anhydride, monoethyl maleate; itaconic acid and its anhydride, monoester of itaconic acid; acrylic acid, methacrylic acid; and salts thereof (sodium Salt, potassium salt, ammonium salt) and the like. Maleic anhydride is preferable. The said monomer can be copolymerized using 1 type, or 2 or more types.

  The radically polymerizable monomer to be grafted may contain other types of monomers as long as the acid value is within the above-mentioned preferable range. As other types of monomers, monomers that can be used when synthesizing the acrylic polymer described above can be used as they are.

  Examples of the graft polymerization initiator used in the present invention include organic peroxides and organic azo compounds known to those skilled in the art. Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxypivalate, and examples of the organic azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2, 4-dimethyl pareronitrile). The amount of the polymerization initiator used for the graft polymerization is at least 0.2% by mass, preferably 0.5% by mass or more, based on the radical polymerizable monomer.

  In addition to the polymerization initiator, a chain transfer agent for adjusting the chain length of the branched polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4-hydroxyanisole may be used as necessary. In this case, it is desirable to add in the range of 0 to 5% by mass with respect to the polymerizable monomer.

  The grafting reaction product is preferably neutralized with a basic compound, and can be easily dispersed in water by neutralization. As the basic compound, a compound that volatilizes at the time of coating film formation is desirable, and ammonia, organic amines, and the like are preferable. Desirable compounds include, for example, triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine , 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanol An amine etc. can be mentioned.

  The basic compound has a pH value of the aqueous dispersion in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization, depending on the carboxyl group content contained in the grafting reaction product. It is desirable to use it. If a basic compound with a boiling point of 100 ° C. or less is used, there are few residual basic compounds in the coating film after drying, and for example, improved hot water adhesion in harsh environments such as high temperature and humidity To do.

  In the grafting reaction product, the weight average molecular weight of the polymer of the radical polymerizable monomer is preferably 500 to 50,000. It is generally difficult to control the weight average molecular weight of the polymer of the radical polymerizable monomer to be less than 500, the graft efficiency is lowered, and there is a tendency that hydrophilic groups are not sufficiently imparted to the copolymer polyester. In addition, the graft polymer of the radical polymerizable monomer forms a hydrated layer of dispersed particles. To obtain a stable aqueous dispersion with a sufficient thickness of the hydrated layer, the graft polymer of the radical polymerizable monomer is used. The weight average molecular weight of is desirably 500 or more.

  The upper limit of the weight average molecular weight of the graft polymer of the radical polymerizable monomer is preferably 50,000 from the viewpoint of polymerizability in solution polymerization. In order to make the weight average molecular weight of the graft polymer of the radical polymerizable monomer within the range of 500 to 50,000, the initiator amount, the monomer dropping time, the polymerization time, the reaction solvent, the monomer composition, or the chain as necessary. It is preferable to carry out by appropriately combining a transfer agent and a polymerization inhibitor.

  The glass transition temperature of the graft copolymer is not particularly limited, but it is preferably 20 ° C. or higher, more preferably 40 ° C. or higher in consideration of heat resistant water adhesion.

  In the present invention, a reaction product obtained by graft polymerization of a radically polymerizable monomer to a hydrophobic copolymerized polyester has a self-crosslinking property because a hydroxyl group in the polyester and a carboxyl group present in the graft portion react. Moreover, although it does not bridge | crosslink at normal temperature, it carries out intermolecular reaction, such as a hydrogen abstraction reaction by a thermal radical, with the heat at the time of drying at the time of coating-film formation, and bridge | crosslinks without a crosslinking agent. As a result, a high degree of heat-resistant water adhesion is exhibited. The degree of crosslinking of the coating film can be evaluated by various methods, and examples thereof include a method of measuring the insoluble fraction in a chloroform solvent or the like that dissolves both the hydrophobic copolymerized polyester and the grafted polymer.

  The insoluble fraction of the coating film obtained by drying at about 80 ° C. and heat-treating at 120 ° C. for 5 minutes is preferably 50% by mass or more, more preferably 70% by mass from the viewpoints of heat resistant water adhesion and blocking resistance. That's it.

  As the self-crosslinking polyester resin aqueous dispersion, for example, a commercially available product such as “Vylonal (registered trademark) AGN702” (manufactured by Toyobo Co., Ltd.) can be used.

  In addition, a grafted polyurethane can be prepared by a method similar to the above.

[Additive for Adhesion Improvement Layer (C)]
In the adhesive improvement layer (C), various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, as long as the effects of the present invention are not impaired. Pigments, dyes, organic or inorganic particles, fillers, antistatic agents, nucleating agents and the like may be blended.

  In particular, when the inorganic particles are added to the adhesion improving layer (C), for example, when the adhesion improving layer (C) is laminated on the surface of the polyester base film (B) and wound once, Since slipperiness and blocking resistance improve, it is preferable. In this case, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, or the like can be used as the inorganic particles to be added. The average particle size used is preferably 0.005 to 5 μm, more preferably 0.01 to 3 μm, and most preferably 0.05 to 2 μm. Although the usage-amount of an inorganic particle is not specifically limited, It is preferable to mix 0.05-10 mass parts with solid content with respect to 100 mass parts of polymers in an adhesive improvement layer (C), More preferably, 0.1-0.1 mass parts. 5 parts by mass.

[Method for Forming Adhesion Improvement Layer (C)]
The adhesion improving layer (C) is an aqueous dispersion of a mixture of at least one polymer selected from the group consisting of polyester, polyurethane and acrylic polymer and a crosslinking agent, or an aqueous dispersion of a self-crosslinking polymer. Therefore, it is most convenient to form by coating method. What is necessary is just to apply | coat the coating liquid for adhesive improvement layers (C) on the opposite surface of the transparent conductive layer of a polyester-type base film (B). Moreover, it apply | coated to the unstretched film of the polyester-type base film (B) before forming a transparent conductive layer (A), and then the method of extending | stretching at least one direction, the method of apply | coating after longitudinal stretching, and the orientation process were complete | finished Any method such as a method of applying to the film surface is possible. In particular, when producing the polyester base film (B), it is applied before the completion of the crystal orientation of the film, and then stretched in at least one direction and then the so-called in-line coating for completing the crystal orientation of the polyester film. Since the method can easily form a thin film, the effect of the present invention can be exhibited more significantly, which is preferable.

  For example, when the coating liquid for (C) is applied to an unstretched film of the polyester base film (B), various coating methods such as reverse coating, gravure coating, rod coating, and bar coating are used. The Meyer bar coating method, the die coating method, the spray coating method and the like can be used.

  In the present invention, the adhesion improving layer (C) needs to be provided between the polyester base film (B) and the silicone rubber pressure-sensitive adhesive layer (D), but the transparent conductive layer (A) and the polyester base You may form also between material films (B). Thereby, the adhesiveness and adhesion durability of a transparent conductive layer (A) may be able to be improved further.

[Adhesive layer (D)]
In the transparent conductive polyester film composite of the present invention, a silicone rubber pressure-sensitive adhesive layer (D) is laminated on the surface of the adhesion improving layer (C). Silicone rubber is excellent in elasticity and can impart cushioning properties to the touch panel.

  The silicone rubber is not particularly limited, but preferably contains a crosslinked silicone compound having a polydimethylsiloxane skeleton as a main component (70% by mass or more, more preferably 90% by mass or more, and further preferably 100% by mass). . In particular, the crosslinked silicone compound having a polydimethylsiloxane skeleton is preferably obtained by crosslinking an uncrosslinked product having a number average molecular weight (Mn) of 50,000 to 500,000. The uncrosslinked Mn is more preferably 80,000 to 400,000, and more preferably 100,000 to 350,000.

  By using the uncrosslinked product of the silicone compound, solubility in a solvent and fluidity can be secured, and formation of the adhesive layer (D) is facilitated. Moreover, since Mn of 50,000 or more of an uncrosslinked body improves crosslinkability, it is suitable. When the Mn of the uncrosslinked product is 500,000 or less, deterioration in operability during production such as the viscosity of the coating solution becoming too high can be suppressed. Therefore, it is a preferred embodiment that an uncrosslinked layer of silicone compound is formed and then crosslinked.

  The raw material of conventionally known silicone rubber is a millable type silicone rubber compound, but such a compound has a lower solubility in a solvent depending on the storage state, and is not dissolved when a silicone rubber layer is applied. The appearance quality may deteriorate depending on the object. In addition, a coating solution in which a silicone rubber compound is dissolved in a solvent has a problem that the gelation of the solution occurs depending on the storage state and cannot be used as a coating solution. By using the above-mentioned uncrosslinked silicone compound, it is superior in quality, quality stability, operability during production, and the like as compared with a case where a conventionally known millable type silicone compound is used as a raw material.

  As an uncrosslinked silicone compound satisfying the above contents, for example, a commercially available silicone oil can be used. When silicone oil is used, non-reactive dimethyl silicone oil is preferably used among straight silicone oils. Thereby, the silicone compound after crosslinking has a polydimethylsiloxane skeleton. The methyl phenyl type silicone oil has poor crosslinkability, and the reactive methyl hydrogen type silicone oil has poor storage stability, which may adversely affect the quality and operability. If it is less than (more preferably less than 5 mass%), you may mix | blend and use the silicone compound which does not have polydimethylsiloxane frame | skeleton, such as a methylphenyl type, a methyl hydrogen type, or various modified types.

  The uncrosslinked silicone compound may contain a polyalkylalkenylsiloxane skeleton silicone compound as long as it is less than 10% by mass. Most preferably, it consists only of a polydimethylsiloxane skeleton silicone compound that does not contain a polyalkylalkenylsiloxane skeleton silicone compound.

  The pressure-sensitive adhesive layer (D) in the present invention may contain a reinforcing agent such as silica as long as it does not interfere with the effects of the present invention, but it is particularly preferred that no reinforcing agent is contained.

  The pressure-sensitive adhesive layer (D) contains an adhesion improver for increasing the adhesive strength between the pressure-sensitive adhesive layer (D) and the adhesion improving layer (C) and making it difficult to peel off the pressure-sensitive adhesive layer (D). May be. As the adhesion improver, it is preferable to use a compound containing a reactive group active against radical reaction. Examples of this compound include (meth) acrylic acid derivatives and allyl derivatives. Among them, derivatives having 2 or more, particularly 3 or more unsaturated bonds are preferred. These compounds are widely used as rubber co-crosslinking agents, and examples include esters of polyhydric alcohol and (meth) acrylic acid, allyl esters of polycarboxylic acid, triallyl isocyanurate, triallyl cyanurate, and the like. .

  The ester of the polyhydric alcohol and (meth) acrylic acid is an ester compound obtained by esterifying two or more alcoholic hydroxyl groups of a polyhydric alcohol having two or more alcoholic hydroxyl groups with (meth) acrylic acid. Specifically, for example, ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, 2,2′-bis [4- (meth) acryloxydiethoxyphenyl] propane, glycerin di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tetramethylolmethane di (meth) acrylate, tetramethylolmethanetri (meth) acrylate, Lame Chi roll tetra (meth) acrylate, dimer diol di (meth) acrylate and the like, particularly compounds containing three or more (meth) acryloyl group is preferred. In addition, although said compound illustrated each single ester compound of acrylic acid and methacrylic acid, the form of mixed ester of acrylic acid and methacrylic acid may be sufficient.

  Examples of the allyl ester of polyvalent carboxylic acid include phthalic acid diarylate, trimellitic acid diarylate, and pyromellitic acid tetraarylate.

  Any one of the above-mentioned adhesiveness improving agents may be used alone, or two or more thereof may be used in combination. In addition, the adhesive improvement agent used for this invention is not limited to said exemplary compound.

  0.2-20 mass parts is preferable with respect to 100 mass parts of silicone compound components, and, as for the compounding quantity of the said adhesive improvement agent, 0.5-10 mass parts is more preferable. By making the compounding amount of the adhesion improver 0.2 parts by mass or more, the effect of improving the hot water adhesion of the pressure-sensitive adhesive layer is further increased. On the other hand, when the compounding amount of the adhesion improver exceeds 20 parts by mass, the effect of improving the hot water adhesiveness not only reaches saturation, but conversely, this effect may be deteriorated.

  The lower limit of the thickness of the adhesive layer (D) is preferably 3 μm, more preferably 5 μm, and even more preferably 8 μm from the viewpoint of adhesive strength. On the other hand, the upper limit of the thickness of the pressure-sensitive adhesive layer (D) may be determined within a range in which the pressure-sensitive adhesive force can be stably maintained from the viewpoint of economy. For example, 100 μm is preferable, 80 μm is more preferable, and 50 μm is further preferable.

  In the present invention, the method for forming the above-mentioned pressure-sensitive adhesive layer (D) is not limited, but the above-mentioned uncrosslinked silicone compound is dissolved or dispersed in a solvent, and if necessary, an adhesion improver is added to the coating solution. It is a preferred embodiment that is prepared by applying a coating method, followed by crosslinking treatment.

  For example, uncrosslinked silicone oil dissolves well in aromatic hydrocarbons such as toluene. Therefore, it is preferable to dissolve in these solvents and apply by a coating method. When an uncrosslinked silicone oil is used, a compound plasticizing step by kneading or the like necessary for dissolving a conventional millable type silicone rubber compound in a solvent is unnecessary. In addition, the obtained coating solution has good storage stability, and does not cause a thickening phenomenon such as gelation, which is often seen when preparing a solution of a silicone rubber compound. Furthermore, since the production | generation of the foreign material by the silicone rubber compound not melt | dissolving which may generate | occur | produce in the solutionization of a silicone rubber compound is suppressed, there exists a merit that a coating liquid with high clarity is obtained.

  The pressure-sensitive adhesive layer (D) is, for example, the surface of the adhesion improving layer (C) formed on the surface of the polyester base film (B) by using a coating liquid containing the silicone oil or the like, or the polyester film (F). It can be formed by coating on the surface of the release layer (E) formed on the surface and laminating or not laminating other layers and carrying out a crosslinking treatment.

  The crosslinking method of the silicone compound may be, for example, thermal crosslinking, or may be crosslinking with high energy active rays such as electron beams and γ rays. It is considered that when an active ray is irradiated on a silicone compound, hydrogen is extracted from the methyl group of polydimethylsiloxane, and a crosslinking reaction occurs between adjacent silicone compounds from which hydrogen is extracted from the methyl group. Therefore, in the crosslinking method using actinic radiation, it is not necessary to add an additive such as a peroxide for radical generation or a crosslinking catalyst to the silicone compound. For this reason, the contamination of the adherend due to the residue of these additives is suppressed, and it is not necessary to consider the pot life after blending the crosslinking catalyst, etc., so that the crosslinking is completed efficiently in a short time. There are merits such as higher.

  Among the actinic rays, the electron beam cross-linking method is preferable because of the availability of an irradiation device (EB irradiation device). As an electron beam irradiation amount in an EB irradiation apparatus, the range of 5-50 Mrad is preferable. By setting the electron beam irradiation amount to 5 Mrad or more, the crosslinking reaction of the silicone compound can be promoted, and the adhesive residue on the adherend can be reduced and the repairability can be improved when re-peeling. On the other hand, by setting the electron beam irradiation amount to 50 Mrad or less, it is possible to suppress a decrease in adhesiveness due to excessive progress of the crosslinking reaction.

  The lower limit of the adhesive strength of the adhesive layer (D) is 0.01 N / 20 mm (against a 180-degree peel test for glass, a pulling speed of 300 mm / min) from the viewpoint of reliability at the time of use when used for laminating articles. Preferably, it is 0.05 N / 20 mm. On the other hand, the upper limit of the adhesive strength of the adhesive layer (D) is preferably 1.0 N / 20 mm, more preferably 0.5 N / 20 mm from the viewpoint of improving removability and ensuring good repairability. is there. Moreover, it is preferable from the point of repair property that the adhesion layer does not remain on the glass surface when evaluated by the above evaluation method, that is, there is no adhesive residue.

  In the present invention, it is preferable that each of the pressure-sensitive adhesive layer (D), the adhesion improving layer (C), and the polyester base film (B) is firmly bonded. For example, when a cutter knife is inserted between the pressure-sensitive adhesive layer (D) and the polyester-based substrate film (B) and peeled by applying force with a finger (exposing the interface), the adhesive strength is strong and the interface is strong. It is preferable that it cannot be taken out. In the present invention, an adhesion improving layer (C) exists between the pressure-sensitive adhesive layer (D) and the polyester base film (B), but the thickness of the adhesion improving layer (C) is thin, so The true interface in the interfacial alignment cannot be analyzed and is not clear. In short, it is preferable that the pressure-sensitive adhesive layer (D) and the polyester-based substrate film (B) are firmly bonded and the interface cannot be formed. Hereinafter, in the present invention, the above characteristic may be simply referred to as adhesiveness.

  Moreover, even if the transparent conductive polyester film composite of the present invention is stored in hot water for a long time, the adhesiveness is preferably maintained. Hereinafter, the adhesive hot water durability may be referred to as heat resistant water adhesiveness.

[Heat resistant water adhesion]
Next, a method for evaluating hot water resistant adhesiveness, which is an important effect of the transparent conductive polyester film composite of the present invention, will be described.

  When measuring the hot water adhesion of the pressure-sensitive adhesive layer (D), the transparent conductive polyester film composite is cut into 50 mm × 50 mm, and a separate film (EF) composed of the polyester film (F) and the release layer (E). ). The sample is submerged in a 500 cc cylindrical glass container with a lid containing 400 cc of distilled water so that the adhesive layer (D) is on the lower side, and the entire sample is immersed in water. Put the lid on. In the case where the sample is not immersed in water by its own weight, for example, a polyester film having a size of 60 mm × 60 mm and a thickness of 188 μm may be placed on the sample and weighted. The size and material of the weight are not particularly limited, and the entire sample may be immersed in water. The container containing the sample is placed in a gear oven set at 80 ° C. and allowed to stand for 24 hours. After the heat treatment, the container is taken out from the oven, and the sample is quickly taken out and rubbed 10 times with the finger pad from the adhesive layer (D) side to the end, and the adhesive layer (D) becomes the polyester base film (B ) Evaluation was made as to whether or not the adhesive layer (D) was peeled from the side.

  In this heat resistant water adhesion, by selecting an adhesion improving layer (C) that does not peel off the adhesive layer (D), for example, when used as a member for a touch panel for car navigation, the adhesive layer (D) Since the interfacial peeling at the interface between the polyester base film (B) and the polyester base film (B) can be suppressed, the reliability of the apparatus is improved.

[Peeling strength between release layer (E) and adhesive layer (D)]
In the transparent conductive polyester film composite of the present invention, a separate film (EF) composed of a release layer (E) and a polyester film (F) is laminated for protecting the adhesive layer (D). At this time, the peel strength between the release layer (E) and the adhesive layer (D) is controlled to 0.03 to 1.0 N / 20 mm. When the peel strength is 0.03 N / 20 mm or more, the film exhibits good peelability, and when winding up the transparent conductive polyester film composite, a separate film composed of a release layer (E) and a polyester film (F). The float of (EF) can be suppressed and the quality of the transparent conductive polyester film composite can be kept high. On the other hand, if it is 1.0 N / 20 mm or less, the peelability of the said separate film (EF) is favorable. In order to control the peel strength within the above range, a release layer (E) having the following constitution is preferably provided on the surface of the polyester film (F). The peel strength is measured as follows.

  First, the surface on which the peel strength of a transparent conductive polyester film composite having a length of about 200 mm and a width of 20 mm is to be exposed is exposed, and the transparent conductive polyester film composite is formed of a laminate including one surface and the other surface. Separately from the laminates to be included, each is set on a chuck of a tensile tester. That is, for example, when measuring the peel strength at the interface between the adhesive layer (D) and the release layer (E), the transparent conductive polyester film composite is formed at the interface between the adhesive layer (D) and the release layer (E). Remove a little to expose each of the adhesive layer (D) and the release layer (E). In this case, the separate film (EF) composed of the release layer (E) and the polyester film (F) is held with one chuck, and the adhesive layer (D) to the transparent conductive layer (A) are held with one chuck. Grip the laminated body up to. Then, the T-type peel strength is measured by the method described in JIS K6854-3. For example, a trade name “Autograph” (manufactured by Shimadzu Corporation) may be used as the tensile tester, and a T-type peel test is performed under conditions of a distance between chucks of 50 mm, a temperature of 23 ° C., and a tensile speed of 200 mm / min. During peeling, the end of the film is lifted with a stick so that the T-shape is maintained. The maximum strength at the time of T-type peeling is defined as peeling strength.

  Hereinafter, in the present invention, the above characteristic may be simply referred to as peelability.

[Release layer (E)]
The release layer (E) in the transparent conductive polyester film composite of the present invention is only required to have a peel strength satisfying the above range, and considering the peelability from the adhesive layer (D), from the non-silicone compound. It is preferable that When the release layer is made of a cured product of a curable silicone compound that is widely used as a release layer, since the affinity with the adhesive layer (D) is high, the silicone compound in the adhesive layer (D) is cross-linked. In addition, the pressure-sensitive adhesive layer (D) and the release layer (E) may undergo a crosslinking reaction, and the peelability may be reduced. In order to obtain stable peelability, the release layer is preferably formed using a release agent that does not substantially contain a silicone compound. Here, “the release layer is made of a non-silicone compound” means that the release layer is formed from a compound (or composition) containing 10% by mass or less of a silicone compound, and more preferable silicone. The compound amount is 5% by mass or less, and the silicone compound is most preferably 0% by mass. The release layer (E) may be the same compound (or composition) or a different compound (or composition).

  The release layer (E) may be composed of a metal or an inorganic thin film. From the viewpoint of peel stability and cost, the release layer (E) is made of a composition containing a binder resin, a polymer wax component and an antistatic agent. It is preferable that it is obtained. The release layer (E) is a set with the polyester film (F) and becomes a separate film (EF) of the adhesive layer (D).

  The binder resin is preferably one or more polymers selected from the group consisting of polyesters, polyurethanes and acrylic polymers. These polymers may be used alone, or two or three different types may be used. May be used in combination.

  As the polyester, polyurethane and acrylic polymer, the same polymers as those exemplified as the constituent polymer of the adhesion improving layer (C) can be used. Although the necessity for crosslinking is low in the binder resin, a crosslinking agent may be used in combination as in the adhesion improving layer (C), or a self-crosslinking polymer may be used.

  As the polymer wax component used in the present invention, conventionally known materials can be used. For example, wax emulsions such as polyethylene, polypropylene, acrylic, and fatty acid are shown, but a polymer wax agent that is particularly hard and does not have a sticky feeling and has excellent thermal decomposition stability is effective in improving peelability. Further, it is preferable because the transfer of wax to the opposite surface can be suppressed during film winding. Moreover, the preferable number average molecular weights of these wax agents are 1000-10000, More preferably, it is the range of 1500-6000.

  The polymer wax component is preferably contained in a solid content of 2 to 10% by mass when the total with the binder resin is 100% by mass. More preferably 3 to 8% by mass is contained. By making the addition amount of the polymer wax component 2% by mass or more, the peelability from the adhesive layer (D) after the crosslinking treatment can be improved, and the slipperiness of the separate film (EF) can be improved. . On the other hand, by setting the addition amount of the polymer wax component to 10% by mass or less, it is possible to maintain the peeling force and suppress the occurrence of the channeling phenomenon in the manufacturing process of the transparent conductive polyester film composite. Furthermore, since the migration of the polymer wax component from the release layer (E) can be suppressed, the surface of the pressure-sensitive adhesive layer (D) after the crosslinking treatment is less likely to be contaminated.

  The antistatic agent used in the release layer (E) is not particularly limited as long as it is miscible with the binder resin or is compatible with the binder resin. For example, any of anionic, cationic, nonionic, amphoteric surfactants, polymeric surfactants, and the like can be used. Preferably, a polymer type antistatic agent with little bleed out to the laminated surface is preferred.

  As the polymer type antistatic agent, any of anionic type, cationic type and nonionic type can be used, and among them, anionic type and nonionic type polymeric antistatic agents are suitable.

  As the anionic polymer antistatic agent, for example, a polar polymer having at least one polar group selected from a sulfonic acid group, a carboxyl group, and a sulfate ester group or a salt thereof is preferable. The polar group needs 5 mol% or more per polymer molecule. These polar polymers having electrical conductivity may contain hydroxyl groups, amino groups, epoxy groups, aziridine groups, active methylene groups, sulfinic acid groups, aldehyde groups, and vinyl sulfone groups as polar groups. Among these, an antistatic agent containing styrene sulfonic acid or a salt thereof as a repeating unit is preferable.

  Examples of such an antistatic agent include polystyrene sulfonic acid or a salt thereof. Examples of the salt include ammonium salt, lithium salt, and sodium salt. Polystyrene sulfonic acid or a salt thereof is, for example, commercially available from Nippon SC under the trade name VERSA-TL (registered trademark) and various types of unneutralized salts having different molecular weights. Further, as an antistatic agent containing styrene sulfonic acid or a salt thereof as a repeating unit, a styrene sulfonic acid-maleic acid copolymer can also be used and is commercially available from Nippon SC.

  On the other hand, nonionic high molecular surfactants include aniline or derivatives thereof, pyrrole or derivatives thereof, isothianaphthene or derivatives thereof, acetylene or derivatives thereof, thiophene or derivatives thereof, and the like. Is preferred. Among them, a π-electron conjugated conductive polymer containing thiophene or a derivative thereof as a structural unit is preferable because it is less colored. The π-electron conjugated conductive polymer may be a homopolymer containing only one type of structural unit as a repeating unit or a copolymer containing two or more types of structural units as a repeating unit.

  Examples of the conductive polymer containing thiophene or a derivative thereof as a constitutional unit include, for example, “BYTRON (registered trademark) P” series manufactured by Starck Vitech, and “Denatron (registered trademark) P-502RG” manufactured by Nagase ChemteX. "Denatron (registered trademark) P-502S", Conisole F202, F205, F210, P810 (above, trade name) manufactured by Inscontec, CPS-AS-X03 (trade name) manufactured by Shin-Etsu Polymer, etc. are commercially available. .

  The blending amount of the antistatic agent in the release layer (E) cannot be uniquely determined because the preferred range varies depending on the type of the binder resin and the type of the antistatic agent, and the adhesion of the release layer (E). What is necessary is just to adjust so that the peeling strength from a layer (D) may become said range, respectively.

  For example, when an anionic surfactant is used as the antistatic agent, the blending amount of the antistatic agent is such that the peel strength of the release layer (E) from the adhesive layer (D) is within the above range. When the total with the binder resin is 100% by mass, the solid content is preferably 2 to 10% by mass, and more preferably 3 to 8% by mass. By making the blending amount of the anionic surfactant 2% by mass or more, the peelability from the pressure-sensitive adhesive layer (D) after the crosslinking treatment is improved, and the antistatic property of the separate film (EF) is also improved. . On the other hand, by setting the blending amount of the antistatic agent to 10% by mass or less, it is possible to maintain the peeling force and suppress the occurrence of the channeling phenomenon in the manufacturing process of the transparent conductive polyester film composite. Furthermore, since the migration of the polymer wax component from the release layer (E) can be suppressed, the surface of the pressure-sensitive adhesive layer (D) after the crosslinking treatment is hardly contaminated.

  In order to form the release layer (E) having the above-described structure on the polyester film (F), other additives such as a binder resin, a polymer wax component, an antistatic agent, and a surface roughening material as required. The resin composition may be prepared by mixing a predetermined amount in advance and coated. The resin composition may contain a surfactant for improving coatability, an ultraviolet ray inhibitor, an antioxidant, and the like. The coating method may be applied using a normal coating apparatus such as a gravure coater, reverse roll coater, reverse kiss coater, air knife coater, bar coater, etc., and the method is not limited to these. As in the case of the adhesion improving layer (C), when the polyester film (F) is obtained, the resin composition is applied to one side of the uniaxially stretched film (F) and further perpendicular to the previous uniaxial stretching. Examples thereof include a so-called in-line coating method of stretching in the direction, a so-called offline coating method of coating after biaxial stretching, and the like.

  The thickness of the release layer (E) is preferably 0.03 to 1 μm and more preferably 0.05 to 0.5 μm in a dry state in order to make the peeling force within an appropriate range.

[Optical properties of transparent conductive polyester film composite]
The transparent conductive polyester film composite of the present invention preferably has a total light transmittance of 80% or more and a haze of 2.0% or less in applications where high transmittance is required. More preferably, the total light transmittance is 85% or more and the haze is 1.0% or less. Furthermore, it is preferable that the total light transmittance and haze are within the above-mentioned preferable range even after storage at 65 ° C. and 85 RH% for 200 hours.

  The transparent conductive polyester film composite of the present invention can be suitably used as a member for an upper electrode of a touch panel by having the above characteristics, but is not limited to this application.

[Method for producing transparent conductive polyester film composite]
The manufacturing method of said transparent conductive polyester film composite is not specifically limited. A typical method is shown below.

  The first method is a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of a release layer (E) of a laminate (1) of a release layer (E) and a polyester film (F). Are laminated to form a laminate (2), and the transparent conductive layer (A) is laminated on one side of the polyester base film (B), and an adhesive improvement layer ( A layered product (3) in which C) is laminated, a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton in the layered product (2), and an adhesion improving layer (C) in the layered product (3) The layered product (2) and the layered product (3) are laminated so as to be in contact with the surface), and then the layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton is crosslinked to obtain a transparent conductive material. In a method to obtain a polyester film composite That.

  In the second method, a laminate (4) is formed by laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the adhesion improving layer (C) of the laminate (3). At the same time, the laminate (1) is such that the release layer (E) of the laminate (1) is in contact with the surface of the layer (4) containing an uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton. And a laminate (4) are laminated, and then a layer containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton is crosslinked to obtain a transparent conductive polyester film composite.

  The third method includes a polyester base film (B), an adhesion improving layer (C), a layer containing an uncrosslinked product of a crosslinked silicone compound having a polydimethylsiloxane skeleton, a release layer (E), and a polyester. A layered product (5) in which films (F) are laminated in this order is formed, then a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton is crosslinked, and a layered product (5 ′) after crosslinking In this method, the transparent conductive layer (A) is formed on the surface of the polyester base film (B) to obtain a transparent conductive polyester film composite.

[Use of transparent conductive polyester film composite]
The transparent conductive polyester film composite of the present invention becomes an upper electrode of a touch panel by being bonded to a touch panel surface layer member such as a plastic film provided with a hard coat layer, an antireflection layer or the like. The present invention includes such an upper electrode for a touch panel. In the upper electrode for a touch panel of the present invention, the adhesive layer (D) of the transparent conductive polyester film composite of the present invention used for the upper electrode is firmly attached to the base film (B) through the adhesion improving layer (C). Combined with the fact that the adhesive layer (D) is excellent in cushioning properties, reliability and durability are improved as compared with the conventional touch panel.

  It is also a preferred embodiment that the transparent conductive polyester film composite of the present invention is used as a lower electrode of a touch panel. When this composite is used as the lower electrode, the touch panel device and the display device can be attached with the adhesive layer (D), and the space between the touch panel device and the display device can be filled with the adhesive layer. As a result, reflection of light at the interface in the space is suppressed, so that the effect of improving the visibility of the display image is exhibited. In addition, since the adhesive layer (D) is made of silicone rubber having both sticking property and removability, it is possible to easily remove both devices even when there is a sticking mistake at the time of sticking. And the effect that it can be re-applied is also exhibited.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, but may be implemented with appropriate modifications within a scope that can meet the gist of the present invention. These are all included in the technical scope of the present invention. The measurement / evaluation methods employed in the examples are as follows. In the examples, “parts” means “parts by mass”, and “%” means “% by mass” unless otherwise specified.

1. Peelability First, for a transparent conductive polyester film composite having a length of about 200 mm and a width of 20 mm, the surface (two faces) on which peelability is to be evaluated is exposed, and the transparent conductive polyester film composite is a laminate including one side. And a laminate including the other surface, and each is set on a chuck of a tensile tester. That is, for example, when measuring the peel strength at the interface between the release layer (E) and the pressure-sensitive adhesive layer (D), the transparent conductive polyester film composite at the interface between the release layer (E) and the pressure-sensitive adhesive layer (D). Is slightly peeled off to expose the release layer (E) and the adhesive layer (D). In this case, the separate film (EF) composed of the polyester film (F) and the release layer (E) is held by one chuck, and the adhesive layer (D) to the transparent conductive layer (A) are held by one chuck. Grasping the laminate. And T-type peeling strength was measured by the method as described in JIS K6854-3. The tensile tester used was a trade name “Autograph” (manufactured by Shimadzu Corporation), and a T-type peel test was performed under conditions of a distance between chucks of 50 mm, a temperature of 23 ° C., and a tensile speed of 200 mm / min. During peeling, the end of the film was lifted with a bar so that the T-shape was maintained. The maximum strength at the time of T-type peeling was defined as the peeling strength.

  When the release layer (E) and the adhesive layer (D) did not peel, it was not measured as difficult to peel. In this case, it indicates that the release layer (E) does not function as a release layer.

2. Adhesiveness A cutter knife was inserted between the pressure-sensitive adhesive layer (D) and the polyester base film (B), and peeling was performed by applying force with a finger (exposing the interface). The case where the adhesion was strong and the interface could not be evaluated was evaluated as ◯, and the case where the interface could be aligned was evaluated as ×.

3. Heat resistant water adhesion The transparent conductive polyester film composite is cut into 50 mm × 50 mm, and the separate film (EF) is peeled off. The sample is submerged in a 500 cc cylindrical glass container with a lid containing 400 cc of distilled water so that the adhesive layer (D) is on the lower side, and the entire sample is immersed in water. Put the lid on. In the case where the sample is not immersed in water by its own weight, for example, a polyester film having a size of 60 mm × 60 mm and a thickness of 188 μm may be placed on the sample and weighted. The size and material of the weight are not particularly limited, and the entire sample may be immersed in water. The container containing the sample is placed in a gear oven set at 80 ° C. and allowed to stand for 24 hours. After the heat treatment, the container is taken out from the oven, and the sample is quickly taken out and rubbed 10 times with the finger pad from the adhesive layer (D) side to the end, and the adhesive layer (D) becomes the polyester base film (B ) Evaluation was made as to whether or not the adhesive layer (D) was peeled from the side.

4). Adhesive strength The adhesive strength of the adhesive layer (D) to the glass was measured by a 180-degree peeling method according to JIS Z0237. As the glass, heat resistant glass having a thickness of 3 mm and a width of 30 mm was used. The sample had a width of 20 mm, and was attached to the glass by reciprocating twice at a speed of about 29 mm / second using a 2 kg roller. The tensile speed was 300 mm / min, a tensile test was performed in an atmosphere at 23 ° C., and the maximum tensile strength was the adhesive strength (N / 20 mm).

5. Total light transmittance A sample obtained by peeling a separate film from a transparent conductive polyester film composite was measured using a haze measuring instrument “NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS K7361-1.

6). Clarity of the coating solution 100cc of each coating solution for forming the adhesive layer (D) is filtered with a 40mmφ 200 mesh (wire diameter 0.04mm) wire mesh to confirm the presence or absence of insoluble matter with the naked eye. In the case of (circle), the case where there existed an insoluble matter was set as x.

7). Solution Stability of Coating Liquid Each of the adhesive layer (D) forming coating liquids was evaluated by a change in viscosity of the solution when stored in a sealed state at room temperature (23 ° C.) for 90 days to determine solution stability. . The case where the change in viscosity of the solution was within ± 20% was marked as ◯, and the case where the change in viscosity of the solution exceeded ± 20% was marked as x. The viscosity was measured with a B-type viscometer.

Example 1
(1) Preparation of adhesion improving layer (C) forming coating solution [Preparation of water-dispersible copolyester resin]
Water-dispersible copolymerization using antimony trioxide as a polycondensation catalyst in a batchwise manner using one pressure esterification reaction tank with a distillation column and two polycondensation reaction tanks with a vacuum generator Polyester was synthesized.

  The copolymer composition of the water-dispersible copolymer polyester is terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // neopentyl glycol / ethylene glycol = 50/43/7 // 70/30 (molar ratio). The reduced viscosity was 0.68 dl / g.

[Preparation of coating solution]
100 parts of the pulverized product of the water-dispersible copolyester was dispersed in water by a conventional method. With respect to 100 parts of the solid content of this aqueous dispersion, 5 parts of methylol melamine resin “Cymel (registered trademark) 303” (manufactured by Mitsui Cytec Co., Ltd.) is used as the catalyst, and “Catalyst 600” (Mitsui Cytec Co., Ltd.) as the catalyst. Product) was added and stirred well to obtain a coating solution (C-1).

(2) Production of polyester base film (B) and lamination of adhesion improving layer (C) Polyethylene terephthalate containing 0.04% amorphous silica having an average particle diameter (SEM method) of 1.5 μm (inherent viscosity 0 .65 dl / g) was sufficiently dried in vacuum, then supplied to an extruder heated to 280 ° C., extruded into a sheet form from a T-shaped die, and a surface temperature of 30 ° C. using an electrostatic application casting method. It was wound around a mirror casting drum and solidified by cooling. The unstretched film was stretched 3.5 times in the longitudinal direction while passing through a heating roll group at 95 ° C. to obtain a uniaxially stretched film. Both surfaces of this film were subjected to corona discharge treatment, and the coating liquid (C-1) was applied to both treatment surfaces. The uniaxially stretched film was guided to a preheating zone while being held with a clip, dried at 110 ° C., and continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C. Further, heat treatment was performed for 6 seconds at 225 ° C. while relaxing 6% in the width direction. A laminate (i) having a thickness of 12 μm was obtained in which a 0.08 μm-thick crosslinked adhesion improving layer (C1) was laminated on both sides of the biaxially stretched polyethylene terephthalate base film (B1).

(3) Preparation of Release Layer (E) Formation Coating Liquid “Vylonal (registered trademark) MD-1200” (manufactured by Toyobo Co., Ltd.), which is a water-dispersible copolymer polyester resin, is used as a binder resin. Polyethylene emulsion wax agent as an antistatic agent, anionic antistatic agent (sodium dodecyldiphenyloxide disulfonate) as an antistatic agent, and styrene-benzoguanamine spherical organic particles having an average particle diameter of 2 μm as a surface roughening material “Eposter (Registered) (Trademark) MS ”(manufactured by Nippon Shokubai Co., Ltd.) and colloidal silica having an average particle diameter of 0.05 μm were used.

  Using a homogenizer, the organic spherical fine particles of the surface roughening material are sufficiently dispersed in a mixed solution of water and isopropyl alcohol (mass ratio 80/20), and then the binder with respect to the total mass of the coating solution. The coating solution is thoroughly mixed so that the resin is 2.5%, the polymer wax component is 0.13%, the antistatic agent is 0.13%, the organic spherical fine particles are 0.025%, and the colloidal silica is 0.3%. (E-1) was prepared.

(4) Manufacture of polyester film (F) and lamination of release layer (E) Pellets of polyethylene terephthalate (intrinsic viscosity 0.65 dl / g) are sufficiently vacuum-dried and then supplied to a heated extruder at 280 ° C. Then, the sheet was extruded from a T-shaped base into a sheet shape, wound around a mirror casting drum having a surface temperature of 30 ° C. using an electrostatic application casting method, and cooled and solidified. The unstretched film was stretched 3.5 times in the longitudinal direction while passing through a heating roll group at 95 ° C. to obtain a uniaxially stretched film. The coating liquid (E-1) prepared by the above method was applied to both surfaces of this uniaxially oriented film. The coated uniaxially stretched film was guided to a preheating zone while being held with a clip, dried at 110 ° C., and continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C. Further, heat treatment was performed for 6 seconds at 225 ° C. while relaxing 6% in the width direction. A laminate (ii) having a thickness of 12 μm in which a release layer (E) having a thickness of 0.15 μm was laminated on both sides of the polyester film (F-1) was obtained. This laminate (ii) is used as a separate film (EF) comprising a polyester film (F) and a release layer (E).

(5) Formation of transparent conductive layer (A) Reactivity using an indium-tin alloy in an atmosphere of 0.533 Pa (4 × 10 ⁻³ Torr) composed of 80% by volume of argon gas and 20% by volume of oxygen gas A transparent conductive layer (A) made of a composite oxide of indium oxide and tin oxide having a thickness of 400 mm is formed on one surface of the laminate (i) produced in (2) by a sputtering method. A laminate (iii) was obtained.

(6) Lamination of adhesive layer (D) Non-reactive comprising a non-crosslinked polydimethylsiloxane skeleton substantially free of reinforcing agents such as silica and having a number average molecular weight of 150,000 (measured by GPC method, converted to polystyrene) The silicone compound (KF-96H-500,000 cs; manufactured by Shin-Etsu Chemical Co., Ltd.) was weighed so that the mass ratio to toluene was 23%, and was put together with toluene into a stirrer equipped with a vacuum defoaming device. The mixture was stirred at room temperature for 15 hours and dissolved in toluene. To the obtained solution, trimethylolpropane trimethacrylate was added to 100 parts of the silicone compound so as to be 2 parts, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. Stir under vacuum for another 20 minutes and degas. Next, the defoamed silicone compound solution is supplied to a roll coater, and the silicone compound solution is dried to a thickness of 25 μm on the opposite surface of the transparent conductive layer (A) of the transparent conductive laminate (iii). It was applied and subsequently introduced into an oven and dried at 80 ° C. A laminate (iv) in which an uncrosslinked adhesive layer (D-1) was formed on one side of the laminate (iii) was obtained.

The laminate (ii) was stacked on the surface of the uncrosslinked adhesive layer (D-1) of the laminate (iv) while being pressed by a pressure roller (pressure 30 N / cm ² ) and continuously laminated. The obtained laminate (v) is continuously introduced into an electron beam irradiation apparatus, and an electron beam is irradiated with energy of 200 KV and 18 Mrad from the laminate (ii) side on the surface of (D-1). Then, the laminate (v ′) having the crosslinked adhesive layer (D1) was wound into a roll. In the manufacturing process so far, the occurrence of the channeling phenomenon of the separate film (EF-1) was not observed.

  Table 1 shows the characteristics of the transparent conductive polyester film composite obtained in Example 1 and the characteristics of the coating liquid for forming the uncrosslinked adhesive layer (D-1).

  The transparent conductive polyester film composite obtained in this example was excellent in transparency. In addition, the pressure-sensitive adhesive layer (D) was firmly bonded to the polyester base film (B) via the adhesive property improving layer (C), and was excellent in adhesiveness and hot water resistance. Moreover, the peeling force of a release layer (E) and the adhesion layer (D) was also moderate, and it was a high-quality transparent conductive polyester film composite excellent in peelability. Furthermore, it is excellent in the clarification and stability of the coating liquid for forming the adhesive layer (D) in the production of the transparent conductive polyester film composite, and it is confirmed that it is excellent in operability and operational stability. did it.

Comparative Example 1
In the method of Example 1, a transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that the application of the coating liquid (C-1) for forming the adhesion improving layer (C) was stopped. The evaluation results are shown in Table 1.

  The transparent conductive polyester film composite obtained in this Comparative Example 1 was inferior in adhesion between the pressure-sensitive adhesive layer (D) and the base film (B) and heat resistant water adhesion, and was of low quality.

Comparative Example 2
In the method of Example 1, the same method as in Example 1 except that the combination of the polymer wax component and the antistatic agent in the coating liquid (E-1) for forming the release layer (E) was stopped. A transparent conductive polyester film composite was obtained. The evaluation results are shown in Table 1.

  The transparent conductive polyester film composite obtained in Comparative Example 2 was inferior in peelability because it could not be peeled off from the pressure-sensitive adhesive layer (D) but the separate film (EF) was peeled off. Therefore, it could not be used as a transparent conductive polyester film composite.

Comparative Examples 3 and 4
In the method of Example 1, in the coating liquid (E-1) for forming the release layer (E), the polymer wax component was used in Comparative Example 3, and the antistatic agent was added in Comparative Example 4, respectively. A transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that it was withdrawn. The evaluation results are shown in Table 1.

  The transparent conductive polyester film composite obtained in Comparative Example 3 could not separate the separate film (EF) from the adhesive layer (D). In Comparative Example 4, the peel strength of the separate film (EF) was high, and the peelability of the separate film (EF) was inferior.

Comparative Example 5
In the method of Example 1, a transparent conductive film was produced in the same manner as in Example 1 except that a separation-treated polyester film (EF) having a thickness of 38 μm and treated with silicone was used (E7002; manufactured by Toyobo Co., Ltd.). A conductive polyester film composite was obtained. The evaluation results are shown in Table 1.

  As in Comparative Example 3, the transparent conductive polyester film composite obtained in Comparative Example 5 tried to peel the separate film (EF) from the adhesive layer (D), but could not be peeled off, and the peelability was poor. It was a thing. It is presumed that the cross-linking adhesion phenomenon occurred due to the EB cross-linking. Therefore, it could not be used as a transparent conductive polyester film composite.

Comparative Example 6
In the method of Example 1, a transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that the thickness of the adhesion improving layer (C) was changed to 0.7 μm. The evaluation results are shown in Table 1.

  The transparent conductive polyester film composite obtained in Comparative Example 6 was inferior in heat resistant water adhesion of the pressure-sensitive adhesive layer (D) and was of low quality.

Comparative Example 7
A transparent conductive polyester film composite was obtained in the same manner as in Comparative Example 1 except that the preparation of the adhesive layer (D) forming coating solution was changed as shown below by the method of Comparative Example 1. . The evaluation results are shown in Table 1.

[Preparation of adhesive layer (D) forming coating solution]
High transparency silicone rubber compound ("TSE260-3U"; rubber hardness 30 degrees) consisting of 60 parts of a polydimethylsiloxane skeleton silicone compound, 25 parts of a polydimethylalkenylsiloxane skeleton silicone compound and 15 parts of silica; Momentive Performance Materials (Made by Japan) was weighed so that the mass ratio with respect to toluene might be 23%, and it poured into the stirrer with a vacuum degassing apparatus with toluene, and it stirred at room temperature for 15 hours under atmospheric pressure, and was dissolved in toluene. To the obtained solution, trimethylolpropane trimethacrylate was added so as to be 2 parts with respect to 100 parts of the rubber compound, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. The mixture was further stirred for 20 minutes and degassed. In addition, the said silicone rubber compound used what passed 6 months after purchase.

  In addition to the problem of the transparent conductive polyester film composite obtained in Comparative Example 1, the transparent conductive polyester film composite obtained in Comparative Example 7 is inferior in the clarity and storage stability of the coating solution. It was.

Example 2
In the method of Example 1, in the same manner as in Example 1 except that the compounding of the methylol melamine resin as a crosslinking agent was stopped in the coating liquid (C-1) for forming the adhesion improving layer (C). A transparent conductive polyester film composite was obtained. The evaluation results are shown in Table 1.

  The transparent conductive polyester film composite obtained in Example 2 was inferior in heat resistant water adhesion between the adhesive layer (D) and the base film (B).

Example 3
In the method of Example 1, 8 parts of organic silicone (“KS-744”; manufactured by Shin-Etsu Chemical Co., Ltd.) and catalyst “PL-3” (Shin-Etsu Chemical Co., Ltd.) were used as the coating liquid for forming the adhesion improving layer (C). A transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that 0.06 part was changed to a solution obtained by dissolving 0.06 part in 100 parts by mass of toluene. The evaluation results are shown in Table 1.

  The transparent conductive polyester film composite obtained in Example 3 was inferior in heat-resistant water adhesion between the adhesive layer (D) and the base film (B).

Example 4
In producing the polyester base film (B) of Example 1, the polyester base film (B2) is prepared in the same manner as in Example 1 except that the application of the coating liquid (C-1) is stopped. Obtained. Corona treatment was performed on both surfaces of this base film (B2). Separately, a copolymerized polyester resin solution (“Byron (registered trademark) 30SS”; manufactured by Toyobo Co., Ltd.) and a polyisocyanate-based crosslinking agent (“Coronate (registered trademark) HX”; manufactured by Nippon Polyurethane Co., Ltd.) It mix | blended so that it might become 100: 3 (part), and the coating liquid (C-2) for adhesive improvement layers (C) was prepared. This coating liquid (C-2) was applied to one side of the base film (B-2) after the corona treatment using a coater and dried. A laminate (i) in which the cross-linked adhesion improving layer (C2) was laminated on one side of the base film (E-2) was obtained. Using this laminate (i), the transparent conductive layer (A) is laminated on the surface where the adhesion improving layer (C2) is not laminated in the same manner as in Example 1, and a transparent conductive polyester film composite is obtained. Obtained. Moreover, the thickness of the adhesive improvement layer (C2) was 0.31 μm. The evaluation results are shown in Table 2.

  The transparent conductive polyester film composite obtained in Example 4 had the same properties as the transparent conductive polyester film composite obtained in Example 1 and was of high quality.

Example 5
In the preparation of the coating liquid (C-2) of Example 4, the transparent conductive material was prepared in the same manner as in Example 1 except that the formulation of “Coronate HX” as a crosslinking agent was stopped and only “Byron 30SS” was used. A conductive polyester film composite was obtained. The evaluation results are shown in Table 2.

  The transparent conductive polyester film composite obtained in Example 5 was inferior in the heat resistant water adhesion of the adhesive layer (D).

Examples 6-8
A transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that the coating liquid for adhesion improving layer (C-1) in Example 1 was changed to the following composition. The evaluation results are shown in Table 2.

  The transparent conductive polyester film composites obtained in these examples had the same characteristics as the transparent conductive polyester film composite obtained in Example 1 and were of high quality.

[Coating liquid of Example 6]
10 parts of the “Cymel 303” and 0.04 part of the “Catalyst 600” with respect to 100 parts of the solid content of the acrylic emulsion (“Joncrill (registered trademark) PDX-7630A”; manufactured by BASF Japan). Were mixed to obtain a coating solution (C-3) for an adhesion improving layer.

[Coating liquid of Example 7]
As an oxazoline-based cross-linking agent ("Epocross (registered trademark) WS-700"; Nippon Shokubai Co., Ltd.) with respect to 100 parts of a solid content of a polyurethane-based aqueous dispersion ("Hydran (registered trademark) AP40"; manufactured by Dainippon Ink and Industry). Product) was added in solid content to give a coating solution for adhesion improving layer (C-4).

[Coating liquid of Example 8]
40 parts of a self-crosslinking polyester resin aqueous dispersion “Vylonal (registered trademark) AGN702” (manufactured by Toyobo Co., Ltd.), 24 parts of water and 36 parts of isopropyl alcohol are mixed, and a 10% aqueous solution of an anionic surfactant 0.6 Part, propionate 1 part, colloidal silica particles (average particle size 40 nm) 20% aqueous dispersion 1.8 parts, dry process silica particles (average particle size 200 nm; average primary particle size 40 nm) 4% aqueous dispersion 1 .1 part was added and it was set as the coating liquid (C-5) for adhesive improvement layers.

Example 9
In the method of Example 1, a transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that a separate film (EF-2) produced by the following method was used. The evaluation results are shown in Table 2.

[Preparation of Separate Film (EF-2)]
The coating liquid (E-1) used in the production of the separate film (EF-1) of Example 1 was applied onto a polyester film (A: 100 μm) using a wire bar (No. 5). The coating amount of the coating liquid (E-1) was about 8 to 10 g (wet state) per 1 m ^{2 of the} base film. The film was dried at 160 ° C. for about 60 seconds to obtain a separate film (EF-2).

  The transparent conductive polyester film composite obtained in Example 9 had the same properties as the transparent conductive polyester film composite obtained in Example 1 and was of high quality. Further, as in Example 1, the separation film was not lifted during the production of the transparent conductive polyester film composite.

Example 10
In the method of Example 1, the polymer wax of the release layer coating solution used for the production of the separate film (EF-1) was changed to an acrylic wax agent emulsion (“ST-200”; manufactured by Nippon Shokubai Co., Ltd.). A transparent conductive polyester film composite was obtained in the same manner as in Example 1 except that. The evaluation results are shown in Table 2.

  The transparent conductive polyester film composite obtained in Example 10 had the same characteristics as the transparent conductive polyester film composite obtained in Example 1 and was of high quality. Further, as in Example 1, the separation film was not lifted during the production of the transparent conductive polyester film composite.

Example 11
In the method of Example 1, the antistatic agent of the release layer coating liquid used for the production of the separate film (EF-1) is changed to an anionic antistatic agent (“TB214”; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Except for the above, a transparent conductive polyester film composite was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.

  The transparent conductive polyester film composite obtained in Example 11 had the same characteristics as the transparent conductive polyester film composite obtained in Example 1 and was of high quality. Further, as in Example 1, the separation film was not lifted during the production of the transparent conductive polyester film composite.

Example 12
In the method of Example 1, the polymer wax component of the release layer coating solution used for the production of the separate film (EF-1) is changed to 0.2% and the antistatic agent to 0.3%. Except for the above, a transparent conductive polyester film composite was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.

  The transparent conductive polyester film composite obtained in Example 12 had the same characteristics as the transparent conductive polyester film composite obtained in Example 1 and was of high quality. Further, as in Example 1, the separation film was not lifted during the production of the transparent conductive polyester film composite.

Comparative Example 8
In the method of Example 1, the polymer wax component of the release layer coating solution used for the production of the separate film (EF-1) is changed to 1.3% and the antistatic agent to 1.5%. Except for the above, a transparent conductive polyester film composite was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.

  The peel strength of the separate film (EF) of the transparent conductive polyester film composite obtained in Comparative Example 8 was almost 0 N / 20 mm, and the peelability was very good, but the polyester film laminate (iv) and During the production of the transparent conductive polyester film composite, the separation film (EF) sometimes floated.

Example 13
On the release layer (E) surface of the separate film (EF) prepared by the same method as in Example 1, the silicone compound solution prepared by the same method as in Example 1 is a roll coater, and the thickness after drying the silicone compound solution is It apply | coated so that it might become 25 micrometers, Then, it introduce | transduced into oven and dried at 80 degreeC. A laminate (vi) in which an uncrosslinked adhesive layer (D-1) was laminated was obtained. The pressure roller (pressure 30N) is applied to the (D-1) layer surface of the laminate (vi) while the opposite surface of the transparent conductive layer (A) of the transparent conductive laminate (iii) obtained by the same method as in Example 1 is overlaid. / Cm ² ) and continuously laminated. The obtained laminate (vii) was wound into a roll. The laminate (vii) was further continuously introduced into an electron beam irradiation apparatus, and the adhesive layer was crosslinked by irradiating an electron beam with energy of 200 KV and 18 Mrad from the side of the separate film (EF). The laminate (vii ′) having the adhesive layer (D) was wound into a roll. In the manufacturing process so far, the occurrence of the channeling phenomenon of the separate film (EF) was not observed.

  The transparent conductive polyester film composite obtained in Example 13 had the same characteristics as the transparent conductive polyester film composite obtained in Example 1 and was of high quality.

Example 14
The separation film (EF) of the transparent conductive polyester film composite obtained by the method of Examples 1 to 13 was peeled off, and the hard coat layer of the 75 μm thick polyester film (transparent substrate) provided with the hard coat layer The upper surface electrode for touch panels was produced by bonding the opposite surface. The workability of these sticking steps was good. In addition, since the adhesive layer (D) is excellent in repairability, it could be easily repaired even if a sticking error occurred. Therefore, it was possible to eliminate the occurrence of defective products due to a sticking mistake.

  A pen sliding durability test was performed by the following method using the upper electrode for the touch panel. That is, the two upper electrodes are arranged opposite to each other so that the transparent conductive layers face each other through a spacer having a thickness of 100 μm, and a load of 5.0 N is applied to a polyacetal pen (tip shape: 0.8 mmR). The linear sliding test was performed 100,000 times (50,000 reciprocations). The sliding distance at this time was 30 mm, and the sliding speed was 60 mm / second.

  After this sliding durability test, first, it was visually observed whether the sliding part was whitened, and no whitening was observed in the electrodes obtained from any of the examples. In addition, when the ON resistance (resistance value when the upper and lower electrodes are in contact) when the sliding portion is pressed with a pen load of 0.5 N was measured, both were kept within three times the initial value. It was confirmed that the pen sliding durability was excellent.

Comparative Example 9
In the method of Example 14, instead of the transparent conductive polyester film composite, two transparent conductive laminates (iii) obtained in Example 1 (laminate before laminating the adhesive layer (D)) were superposed. A pen sliding durability test was conducted in the same manner as in Example 14 except that. The sliding portion was whitened, and the ON resistance value was 15 times the initial value, which was inferior in pen sliding durability.

  When the transparent conductive polyester film composite of the present invention includes a transparent conductive layer and a silicone rubber pressure-sensitive adhesive layer having both sticking property and removability, it is used as, for example, a member of a touch panel. When there is a sticking mistake, etc., the complex can be easily removed and it can be pasted again. In addition, the adhesive layer is firmly bonded to the base film through the adhesive improvement layer, and the adhesive layer is excellent in cushioning properties, thereby improving the reliability and durability of the touch panel. Can do. Thus, a high-performance touch panel can be provided.

Claims (11)

At least the transparent conductive layer (A), the polyester base film (B), the adhesion improving layer (C), the silicone rubber adhesive layer (D), the release layer (E) and the polyester film (F) are in this order. A laminated transparent conductive polyester film composite, wherein the pressure-sensitive adhesive layer (D) comprises an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton having a number average molecular weight of 50,000 to 500,000, and an adhesion improver. A composition containing a (meth) acrylic acid ester of a polyhydric alcohol is crosslinked, and the adhesive layer (D) and the release layer (E) are measured by the method defined in the specification. A transparent conductive polyester film composite having a peel strength of 0.03 to 1.0 N / 20 mm.   The transparent conductive polyester film composite according to claim 1, wherein the adhesive layer (D) is not peeled off when the hot water adhesion is evaluated by a method defined in the specification.   The transparent conductive polyester film composite according to claim 1 or 2, wherein the release layer (E) comprises a non-silicone compound.   The transparent conductive polyester film composite according to any one of claims 1 to 3, wherein the release layer (E) is a layer containing a binder resin, a polymer wax component and an antistatic agent.   The transparent conductive polyester film composite according to any one of claims 1 to 4, wherein an adhesion improving layer (C) is provided between the transparent conductive layer (A) and the polyester base film (B). body.   The transparent conductive polyester film composite according to any one of claims 1 to 5, wherein the adhesive improvement layer (C) has a thickness of 0.01 to 0.5 µm and contains a crosslinked polymer.   The said adhesive improvement layer (C) contains the reaction product of 1 or more types of polymers selected from the group which consists of polyester, a polyurethane, and an acrylic polymer, and a crosslinking agent in any one of Claims 1-6. The transparent conductive polyester film composite described in 1.   The said adhesive improvement layer (C) contains what self-crosslinked one or more types of self-crosslinked polymers selected from the group consisting of self-crosslinked polyester, polyurethane and acrylic polymers. The transparent conductive polyester film composite according to any one of the above. The transparent conductive polyester film composite according to any one of claims 1 to 8 , which is used as a member of a touch panel. The transparent according to claim 9 , wherein the release layer (E) and the polyester film (F) are peeled off and then attached to a transparent base material subjected to hard processing to be used as an upper electrode of a touch panel. Conductive polyester film composite. The transparent conductive polyester film composite according to any one of claims 1 to 8, wherein the release layer (E) and the polyester film (F) are peeled off and attached to a transparent base material subjected to hard processing. An upper electrode for a touch panel, comprising the laminate obtained in this way.