JP2017076586A - Conductive film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive film that forms an Si-containing layer between a resin film and a conductive layer, thereby stabilizing the surface resistance value of the conductive film and also ensuring adhesion.SOLUTION: A conductive film includes a resin film 1, an Si-containing layer 2, and a conductive layer 3 in the stated order, where the Si-containing layer 2 and the conductive layer 3 directly contact with each other, the Si-containing layer 2 contains SiOx (x=0-2.0), and the Si-containing layer 2 has a thickness of 1 nm-10 nm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive film including a resin film, a Si-containing layer, and a conductive layer in this order, and a method for manufacturing the conductive film. The conductive film of the present invention can be used for electromagnetic wave shield sheets, flat panel displays, sensors, solar cells and the like.

  Conventionally, conductive films in which a conductive layer is formed on a surface of a resin film by fusing or plating a metal foil are used for electromagnetic wave shielding sheets, flat panel displays, sensors, solar cells, and the like. Generally, Cu is often used for the conductive layer because of its low electrical resistivity and low cost (Patent Document 1, etc.), but Cu is easily oxidized and its conductivity is likely to decrease. On the other hand, in recent years, with the high integration and compactness of electronic components in electronic devices and the like, the portion to which the conductive film is attached is becoming narrower, and there is a demand for ensuring adhesion during the attachment.

  Patent Document 1 discloses a conductive film in which an adhesion layer and a metal layer are formed in this order on a resin film, and the composition of the adhesion layer is made of NiCu. However, when a NiCu layer is provided, there are many manufacturing restrictions such as sputtering not suitable, and there is room for further improvement.

Patent Document 2 discloses that an undercoat layer made of SiO ₂ is provided between a base material and a Cu layer to improve visibility (prevention of pattern appearance) by adjusting the refractive index. However, since an ITO layer or the like exists between the SiO ₂ layer and the Cu layer, it is difficult to achieve both stabilization of the surface resistance value and adhesion of the Cu layer.

JP2015-056321A JP 2013-229122 A WO2013 / 103104 gazette

Patent Document 3 discloses that a transparent dielectric layer made of SiO ₂ is provided between a PET substrate and an ITO layer to improve acid resistance and prevent deterioration during ITO etching. However, it has been found that the adhesion is not sufficient because the thickness is large to increase acid resistance.

  Accordingly, an object of the present invention is to provide a conductive film capable of stabilizing the surface resistance value of the conductive film and ensuring adhesion, by forming a Si-containing layer between the resin film and the conductive layer. There is to do.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by adopting the following configuration, and have arrived at the present invention.

  That is, the conductive film of the present invention is a conductive film including a resin film, a Si-containing layer, and a conductive layer in this order, and the Si-containing layer and the conductive layer are in direct contact with each other, The Si-containing layer contains SiOx (x = 0 to 2.0), and the thickness of the Si-containing layer is 1 nm to 10 nm. In addition, the various physical property values in the present invention are values measured by a method employed in Examples and the like.

  In the present invention, as described above, the Si-containing layer is formed with a predetermined thickness between the resin film and the conductive layer so as to be in direct contact with the conductive layer. While being able to stabilize a surface resistance value, the adhesiveness between a resin film and a conductive layer can be ensured.

  Although the mechanism of fluctuation of the surface resistance value is not clear, it is considered as follows. As in the past, when a conductive film in which only a conductive layer such as Cu is laminated on a resin film such as PET is examined for changes in surface resistance over time under humidified heat conditions of 65 ° C. and 90% RH, It has been confirmed that the layer (Cu) is oxidized and the surface resistance value gradually increases. Since Cu forms an oxide film (copper oxide) or the like to make it non-conductive, once the oxide film is formed on the outermost surface side of the Cu layer (the side where the PET base material is not formed), it is oxidized further. It is hard to be done. However, since the surface resistance value gradually increases under humidified heat conditions, the inventors of the present application speculated that any other part of the conductive layer (Cu) may be oxidized. The inventor of the present application confirmed the proportion of oxygen atom content in the conductive film after heating. In particular, the oxygen atom content increased in the PET conductive layer (Cu), and copper oxide was formed. I was able to confirm that. Therefore, by forming a rust preventive layer between the resin film and the conductive layer and preventing oxidation of the conductive layer (Cu) mainly from the PET side, the surface resistance of the conductive film under humidified heat conditions I thought that the rise of the value could be prevented. The reason for the oxidation of the conductive layer (Cu) on the PET side is that it is oxidized by gas generated from PET during heating, or that moisture or the like permeates through a resin film such as PET (the permeability of a resin film such as PET). It is thought that the oxidation due to moisture permeability is affected. In addition, it is thought that the influence of the thinning of the resin base material by the downsizing of electronic devices in recent years is also large.

  Although the mechanism for ensuring adhesion is not clear, it is considered as follows. When a conductive film in which a conductive layer such as Cu is laminated via a Si-containing layer on a resin film such as PET is formed, compared to a case in which a conductive layer such as Cu is directly laminated on a resin film such as PET. Stress is likely to occur, and peeling is likely to occur at the interface between the resin film and the Si-containing layer, which is the most vulnerable part of adhesion. However, by reducing the thickness of the Si-containing layer, the stress can be reduced, peeling between layers or layers can be prevented, and adhesion can be ensured.

  The Si-containing layer in the present invention preferably has a region having a lower oxygen concentration on the surface side of the resin film than the surface in contact with the conductive layer. As described above, the Si-containing layer has a region where the Si element ratio is higher on the resin film side and a region where the Si element ratio is lower on the conductive layer side. Since the affinity between the respective layers having different physical properties can be increased, the adhesion between the resin film and the conductive layer can be ensured.

  The conductive layer in the present invention preferably contains copper. Thereby, since the electrical resistivity is sufficiently small and the conductivity is high, the electromagnetic wave shielding characteristics can be improved and the sensor can be easily used.

  The thickness of the conductive layer in the present invention is preferably 50 nm to 500 nm. By setting it as this thickness, sufficient electroconductivity can be ensured and the surface resistance value of the electroconductive film under humidification heat conditions can be stabilized. In addition, since there is a certain thickness, even if the outermost surface side of the conductive layer is oxidized to form a film, the influence from the oxide film can be reduced, and sufficient conductivity can be secured.

  The resin film in the present invention preferably has an easy-adhesion layer on the outermost surface, and the easy-adhesion layer and the Si-containing layer are preferably in direct contact. Thereby, while being able to prevent oligomer precipitation from a resin film, since permeation | transmission of the water | moisture content, gas, etc. from a resin film can be prevented, a rust prevention function can be exhibited efficiently. Furthermore, since the affinity between each layer which has a mutually different physical property can be improved by making a direct contact, the adhesiveness with each layer can be ensured.

  The resin film in the present invention preferably contains a polyester resin. Thereby, while being able to obtain the electroconductive film with favorable mechanical characteristics and workability, the electroconductive film excellent in versatility can be obtained.

  The electromagnetic wave shielding sheet of the present invention preferably includes the conductive film. By including the conductive film of the present invention, the surface resistance value of the conductive film under humidified heat conditions is stable, and an electromagnetic wave shield sheet having sufficiently high conductivity and improved electromagnetic wave shielding characteristics can be obtained. Moreover, since there is no film peeling at the time of heat processing etc., the electromagnetic shielding sheet which is excellent in production efficiency and practical is obtained.

  The planar sensor of the present invention preferably includes the conductive film. By including the conductive film of the present invention, the surface resistance value of the conductive film under humidified heat conditions is stable, and a planar sensor with sufficiently high conductivity and improved sensor function can be obtained. Moreover, since there is no film peeling at the time of heat processing etc., the surface sensor which is excellent in production efficiency and practical is obtained.

  The method for producing a conductive film of the present invention is a method for producing a conductive film including a resin film, a Si-containing layer, and a conductive layer in this order, and by performing sputtering using a Si target, The step of forming the Si-containing layer so as to contain SiOx (x = 0 to 2.0) on the film and having a thickness of 1 nm to 10 nm, wherein the step of forming the Si-containing layer is performed by sputtering. A step of forming a Si layer on the resin film without introducing oxygen into the gas; and a step of introducing oxygen into the sputtering gas to form a SiOx layer on the Si layer, and a Si-containing layer It has the process of forming a conductive layer directly on it. Thereby, while being able to stabilize the surface resistance value of the electroconductive film under humidification heat conditions, the electroconductive film which ensured the adhesiveness of a resin film and a conductive layer can be manufactured. In particular, by introducing oxygen after sputtering without introducing oxygen using a Si target, the Si-containing layer has a higher Si element ratio on the resin film side, and the conductive layer side Therefore, it is easy to have a concentration gradient in which the proportion of Si element is low, and the affinity between layers having different physical properties can be increased, which is advantageous in obtaining the effects of the present invention.

  In the step of forming the conductive layer in the present invention, it is preferable to perform sputtering without introducing oxygen into the sputtering gas using a metal target. Thereby, since it is easy to obtain a conductive layer having a sufficiently small electrical resistivity and high conductivity, the electromagnetic wave shielding characteristics can be improved and the sensor can be easily used as a sensor.

It is typical sectional drawing of the electroconductive film which concerns on one Embodiment of this invention. It is typical sectional drawing of the electroconductive film which concerns on other embodiment of this invention. In the electroconductive film of Example 1 of this invention and the comparative example 1, it is a graph which shows resistance value change rate by a time-dependent change at 65 degreeC90% RH.

  Embodiments of the conductive film of the present invention will be described below with reference to the drawings. However, in some or all of the drawings, parts unnecessary for the description are omitted, and there are parts shown enlarged or reduced for easy explanation. The terms indicating the positional relationship such as up and down are merely used for ease of explanation, and are not intended to limit the configuration of the present invention.

<Conductive film>
FIG. 1 is a schematic cross-sectional view of a conductive film according to an embodiment of the present invention. The conductive film shown in FIG. 1 includes a resin film 1, a Si-containing layer 2, and a conductive layer 3 in this order. The Si-containing layer 2 and the conductive layer 3 each have a single-layer structure, but each may have a multilayer structure of two or more layers.

  FIG. 2 is a schematic cross-sectional view of a conductive film according to another embodiment of the present invention. In FIG. 2, for ease of explanation, the Si-containing layer 2 includes the Si layer 21 and the SiOx layer 22 and is illustrated so as to be distinguished as a layer. For example, the Si-containing layer 2 may have a concentration gradient so that the surface of the resin film 2 has a region having a lower oxygen concentration than the surface in contact with the conductive layer 3. In other words, there may be a region having a high Si element ratio (region corresponding to the Si layer 21) on the resin film 1 side and a region having a low Si element ratio (region corresponding to the SiOx layer 22) on the conductive layer 3 side. is there.

  Although not shown, a cured resin layer can be further provided on the resin film 1. The cured resin layer can be formed on one side or both sides of the resin film 1 or the like, and can also have a configuration of one or more layers. The cured resin layer includes those that function as an easy adhesion layer, a hard coat layer, an undercoat layer, a dielectric layer, an anti-blocking layer, and the like. Furthermore, one side or both sides of the resin film 1 may be a separator or the like that is bonded to another substrate using an appropriate adhesive means such as an adhesive, or an adhesive layer for bonding to another substrate. The protective film may be temporarily attached.

(Resin film)
The resin film is not particularly limited as long as it can ensure insulation, and various plastic films are used. Examples of the resin film material include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyimide resins such as polyimide (PI), polyethylene (PE), polypropylene (PP ) And other polyolefin resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, cycloolefin resins, (meth) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene Resin, polyvinyl alcohol resin, polyarylate resin, polyphenylene sulfide resin and the like. Among these, from the viewpoint of heat resistance, durability, flexibility, production efficiency, cost, etc., polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyimide resins such as polyimide (PI) are used. preferable. In particular, polyethylene terephthalate (PET) is preferable from the viewpoint of cost performance.

  The resin film is preliminarily subjected to etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, and undercoating treatment, and adhesion to the Si-containing layer formed on the resin film. You may make it secure sex. Moreover, before forming a Si content layer etc., you may remove and clean the resin film surface by solvent washing | cleaning, ultrasonic washing | cleaning, etc. as needed.

  The thickness of the resin film is preferably in the range of 2 to 200 μm, more preferably in the range of 10 to 100 μm, and still more preferably in the range of 20 to 60 μm. In general, a thick resin film is desirable because it is less susceptible to thermal shrinkage during heating. However, it is desirable to reduce the thickness of the resin film to some extent due to downsizing of electronic parts and the like. On the other hand, when the thickness of the resin film is too thin, the moisture permeability and permeability of the resin film are increased, and moisture, gas, and the like are transmitted, and the conductive layer is easily oxidized. Therefore, in the present invention, by reducing the thickness of the resin film while maintaining a certain thickness, the conductive film itself can also be reduced, and the thickness when used for an electromagnetic shielding sheet, a sensor, or the like can be suppressed. Become. Therefore, it can respond to thickness reduction of an electromagnetic wave shield sheet, a sensor, etc. Furthermore, when the thickness of the resin film is within the above range, the mechanical strength is sufficient while ensuring the flexibility of the resin film, and the film is rolled to continuously form a Si-containing layer or a conductive layer. Can be operated.

  Further, a cured resin layer such as an easy adhesion layer, a hard coat layer, an undercoat layer, a dielectric layer, or an anti-blocking layer may be formed on one or both sides of the resin film. In addition, it is the one that another substrate is bonded using an appropriate adhesive means such as a pressure-sensitive adhesive, or the one that a protective film such as a separator is temporarily attached to the pressure-sensitive adhesive layer for bonding to another substrate. There may be.

(Easily adhesive layer)
One or more easy-adhesion layers can be formed between the resin film and the Si-containing layer. Thereby, while being able to improve adhesiveness with a Si content layer, oligomer precipitation from a resin film can be prevented. The easy-adhesion layer may be formed from a composition having at least one polymer component selected from the group consisting of acrylic polymer, polyester, polyurethane and polyvinyl alcohol, and having a functional group capable of forming a crosslinked structure. it can. In addition to the polymer component, a polymer component such as an amino resin, an epoxy resin, polystyrene, or polyvinyl acetate can be used for the composition. The other polymer component can be used in a range of 40% by weight or less based on the total polymer component.

  The acrylic polymer has an alkyl (meth) acrylate monomer unit as a main skeleton. (Meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning. The alkyl group of the alkyl (meth) acrylate constituting the main skeleton of the acrylic polymer has about 1 to 14 carbon atoms, and these can be used alone or in combination. Alkyl (meth) acrylates having 1 to 9 carbon atoms in the alkyl group are preferred.

  One or more kinds of various monomers can be introduced into the acrylic polymer by copolymerization. Specific examples of the copolymerization monomer include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, a nitrogen-containing monomer (including a heterocyclic ring-containing monomer), an aromatic-containing monomer, and the like. Among these, a carboxyl group-containing monomer such as a hydroxyl group-containing monomer or acrylic acid is preferably used because of its good reactivity with the crosslinking agent. The ratio of the copolymerizable monomer in the acrylic polymer is not particularly limited, but is 50% by weight or less in terms of weight ratio. Preferably it is 0.1 to 10 weight%, More preferably, it is 0.5 to 8 weight%, More preferably, it is 1 to 6 weight%.

  The production of the acrylic polymer can be appropriately selected from known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. The obtained acrylic polymer may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

  As the polyester, various resins having a polyester skeleton can be used. The polyester may be a copolyester or a homopolyester. The polyester is preferably obtained by polycondensation of a dicarboxylic acid component and a glycol component. Examples of the dicarboxylic acid include terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxybenzoic acid, etc.), etc. 1 type or 2 types or more are mentioned. As a glycol component, 1 type, or 2 or more types, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexane dimethanol, neopentyl glycol, is mentioned. A functional group such as a carboxyl group, a sulfonic acid group or a salt thereof can be introduced into the polyester to impart water dispersibility.

  As the polyurethane, various resins having a polyurethane skeleton can be used. Polyurethane is usually made by the reaction of a polyol component and an isocyanate compound. Examples of the polyol component include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination. The polyurethane can be imparted with water dispersibility by introducing a functional group such as a carboxyl group, a sulfonic acid group or a salt thereof.

  As the polyvinyl alcohol, various resins having a polyvinyl alcohol skeleton or the like can be used. In addition, polyvinyl alcohol is obtained by saponifying polyvinyl acetate; derivatives thereof; saponification products of copolymers with vinyl acetate and monomers having copolymerizability; acetalizing polyvinyl alcohol , Modified butyral alcohol, urethanization, etherification, grafting, phosphoric esterification and the like. Moreover, the polyvinyl alcohol which has an acetoacetyl group etc. is mentioned. The degree of polymerization of polyvinyl alcohol is not particularly limited, but is usually 100 or more, preferably in the range of 300 to 40,000. The degree of saponification of polyvinyl alcohol is not particularly limited, but is preferably 70 mol% or more, and preferably in the range of 70 to 99.9 mol%.

  The polymer component may be either water-based or solvent-based, but these polymer components can be used singly or in combination of two or more. The polymer component may be either water-based or solvent-based. In addition, when using a stretched film as a resin film, the easy-adhesion layer can be formed by in-line coating during film stretching. In such a case, it is preferable to use a water-based polymer component because it can be applied even with non-explosion-proof equipment. The aqueous polymer component may be either water-soluble or water-dispersible.

  In the easy-adhesion layer of the present invention, the composition having the polymer component has a functional group capable of forming a crosslinked structure. The functional group capable of forming the crosslinked structure includes, for example, at least one compound (crosslinking component) selected from the group consisting of an epoxy compound, an oxazoline compound, and a melamine compound in addition to the polymer component in the composition. It can contain in the said composition by mix | blending. In addition, the functional group capable of forming the crosslinked structure contains, as the polymer component, a self-crosslinking property containing, as the functional group capable of forming the crosslinked structure, at least one functional group selected from the group consisting of an oxazoline group and a carbodiimide group. By using the polymer component, it can be contained in the composition. For the composition, a compound having a functional group capable of forming a crosslinked structure using a self-crosslinkable polymer component can be used.

  Examples of the crosslinking component include an epoxy compound, an oxazoline compound, a melamine compound, boric acid, an isocyanate compound, and a silane coupling agent. Among these, as a crosslinking component, an epoxy compound, an oxazoline compound, and a melamine compound are preferable. The crosslinking component can be appropriately selected according to the polymer component. The blending ratio of the crosslinking component is usually preferably 50 parts by weight or less, more preferably 1 to 40 parts by weight, and further preferably 5 to 30 parts by weight with respect to 100 parts by weight of the polymer component.

  As an epoxy compound, the compound containing an epoxy group in a molecule | numerator, its prepolymer, and hardened | cured material are mentioned, for example. Examples include condensates of epichlorohydrin with hydroxyl groups and amino groups such as ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and bisphenol A, and polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like. is there. Examples of the polyepoxy compound include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylol. Examples of the propane polyglycidyl ether and diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether. Ether, polypropylene glycol diglycidyl ether, Ritetramethylene glycol diglycidyl ether and monoepoxy compounds include, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidyl amine compounds such as N, N, N ′, N ′,-tetraglycidyl-m. -Xylylenediamine, 1,3-bis (N, N-diglycidylamino) cyclohexane and the like.

  The melamine compound is a compound having a melamine skeleton in the compound. For example, an alkylolated melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and a mixture thereof can be used. As alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Moreover, as a melamine compound, either a monomer or a multimer more than a dimer may be sufficient, or a mixture thereof may be used. Further, a product obtained by co-condensing urea or the like with a part of melamine can be used, and a catalyst can be used to increase the reactivity of the melamine compound.

  As the oxazoline compound, a compound having two or more oxazoline groups in the molecule is preferably used. Specifically, 2′-methylenebis (2-oxazoline), 2,2′-ethenebis (2-oxazoline), 2, 2'-ethenebis (4-methyl-2-oxazoline), 2,2'-propenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2,2'-hexamethylenebis (2 -Oxazoline), 2,2'-octamethylenebis (2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4,4'-dimethyl- 2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'-p (phenylenebis (4-phenyl-2-oxazoline) And the like.

The easy-adhesion layer is controlled such that the amount of oligomer deposited on the surface of the easy-adhesion layer is 1.0 mg / m ² or less after heat-treating the resin film at 150 ° C. for 1 hour. Yes. The oligomer precipitation amount is preferably 0.8 mg / m ² or less, more preferably 0.5 mg / m ² or less.

  The oligomer precipitation amount is determined by selecting the material for forming the easy-adhesion layer and adjusting the proportion of the functional group capable of forming the crosslinked structure in the crosslinking component and / or self-crosslinkable polymer forming the crosslinked structure. Can be controlled. In addition, since adhesiveness will fall if the crosslinking density of an easily bonding layer becomes high too much, in the range by the ratio of the functional group which can form the crosslinked structure in the said crosslinking component and / or self-crosslinking polymer. It is preferable to adjust.

  The easy-adhesion layer is formed by preparing a composition (formation material for an easy-adhesion layer) containing the polymer component (which is a self-crosslinkable polymer and / or containing a cross-linking component) and placing the formation material on the film. In addition, it is performed by coating and drying by a known technique. The material for forming the easy-adhesion layer is usually adjusted as a solution diluted to an appropriate concentration in consideration of the thickness after drying and the smoothness of coating. The thickness after drying of an easily bonding layer becomes like this. Preferably it is 0.01-5 micrometers, More preferably, it is 0.02-2 micrometers, More preferably, it is 0.03-1 micrometers. Note that a plurality of easy-adhesion layers can be provided, but also in this case, the total thickness of the easy-adhesion layers is preferably in the above range. In addition, when a resin film is a stretched film, an easily bonding layer can be formed in the film before extending | stretching.

(Cured resin layer)
Although the cured resin layer can be directly formed on one or both sides of the resin film, the cured resin layer can also be formed on the easily adhesive layer. As a result, resin films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyimide (PI) tend to be very easily damaged by themselves, but the formation of conductive layers and Si-containing layers or electronic devices It is possible to prevent the resin film from being damaged in each process such as mounting.

  As a material for forming the cured resin layer, a material having sufficient strength as a film after forming the cured resin layer can be used without any particular limitation. Examples of the resin to be used include thermosetting resins, thermoplastic resins, ultraviolet curable resins, electron beam curable resins, and two-component mixed resins. Among these, simple curing treatment by ultraviolet irradiation is possible. An ultraviolet curable resin capable of efficiently forming a cured resin layer by a processing operation is preferable.

  Examples of ultraviolet curable resins include polyester resins, acrylic resins, urethane resins, amide resins, silicone resins, epoxy resins, and the like, including ultraviolet curable monomers, oligomers, and polymers. included. As the ultraviolet curable resin preferably used, an acrylic resin or an epoxy resin is preferable.

  Various additives can be added to the cured resin layer as necessary. Such additives include conventional additives such as fine particles, antistatic agents, plasticizers, surfactants, antioxidants, and ultraviolet absorbers.

  The cured resin layer is formed by applying a resin composition containing each curable resin and a crosslinking agent, an initiator, a sensitizer, and the like to be added as necessary on the resin film. When the resin composition contains a solvent, Is dried and cured by application of either heat, active energy rays or both. For the heat, known means such as an air circulation oven or an IR heater can be used, but it is not limited to these methods. Examples of active energy rays include, but are not limited to, ultraviolet rays, electron beams, and gamma rays.

  The thickness of the cured resin layer is not particularly limited, but is preferably 0.5 μm to 5 μm, more preferably 0.7 μm to 3 μm, and most preferably 0.8 μm to 2 μm. When the thickness of the cured resin layer is in the above range, precipitation of low molecular weight components such as oligomers from the plastic film can be suppressed, and scratch resistance can be ensured.

(Si-containing layer)
The Si-containing layer is formed between the resin film and the conductive layer, and is formed so as to be in direct contact with the conductive layer. Thereby, while functioning as a rust prevention layer for preventing a conductive layer from rusty, it can function also as an adhesion layer which ensures the adhesiveness of a resin film and a conductive layer. Here, “rusting” includes that a metal contained in the conductive layer is oxidized and a corrosion product is generated. Specifically, the rust prevention layer is formed, for example, to prevent oxidation of the conductive layer due to gas generated from a resin film such as PET during heating, or oxidation of the conductive layer due to moisture or the like that has passed through the resin film. . In addition, it is preferable that a Si content layer is formed so that it may contact directly on a resin film from a viewpoint of rust prevention property and adhesive improvement.

  The Si-containing layer contains SiOx (x = 0 to 2.0). The Si-containing layer may be composed of one layer or may be composed of two or more layers. The Si-containing layer has a Si layer and a SiOx layer, and may be distinguished as a layer. In this case, the Si layer functions as an adhesion layer that ensures the adhesion between the resin film and the conductive layer, and the SiOx layer mainly functions as a rust prevention layer for preventing the conductive layer from being rusted. However, the layers may not be distinguished because the thickness of each layer is too thin. In that case, it is preferable that the Si-containing layer has a concentration gradient so that the surface of the resin film has a region having a lower oxygen concentration than the surface in contact with the conductive layer. That is, the Si-containing layer has a region having a high Si element ratio on the resin film side (region corresponding to the Si layer) and a region having a low Si element ratio on the conductive layer side (region corresponding to the SiOx layer). Is preferred. In this case, the region with a high Si element ratio exhibits an adhesion function that ensures the adhesion between the resin film and the conductive layer, and the region with a low Si element ratio prevents rusting of the conductive layer. The main function can be demonstrated. Note that a region having a high Si element ratio can also be referred to as a region having a low oxygen molar ratio, and a region having a low Si element ratio can also be referred to as a region having a high oxygen molar ratio.

  Here, the concentration gradient is a concentration gradient (SiOx) of the oxygen molar ratio in the thickness direction of the Si-containing layer, and this concentration gradient changes stepwise or continuously. The concentration gradient that changes stepwise means that the Si element concentration (or oxygen concentration) decreases or increases stepwise in the film thickness direction. For example, the horizontal axis indicates the film thickness, and the vertical axis indicates the Si element concentration. When a graph representing the above is created, a line connecting a plurality of plotted points becomes a step-like trajectory that goes up or down to the right. Further, the concentration gradient that continuously changes means that the change in the Si element concentration (or oxygen concentration) is smooth in the film thickness direction. For example, the horizontal axis represents the film thickness, and the vertical axis represents the Si element concentration. When a graph representing the above is created, a line connecting a plurality of plotted points becomes a curve or straight line that rises to the right or descends to the right.

  Specifically, in a region where the ratio of Si layer or Si element is high (region corresponding to the Si layer), the element ratio of Si and O in silicon oxide (SiOx) is SiOx (x = 0 to 1.5) is preferred, and SiOx (x = 0 to 1.0) is more preferred. By forming a Si-rich layer or region in the Si-containing layer in this manner, a bond or the like that does not participate in the bond is generated, and the bond with the adjacent layer or region can be maintained. Can be secured. Although it is more preferable to contain a large amount of Si alone (that is, it is preferred that SiOx is close to x = 0), even if a layer or region made of Si alone is formed, due to the influence of changes over time, the above The composition ratio may change as in SiOx.

  In addition, in the SiOx layer or the region where the ratio of Si element is low (region corresponding to the SiOx layer), the element ratio of Si and O of silicon oxide (SiOx) is SiOx (x = 1) from the viewpoint of improving rust prevention. 0.0 to 2.0), SiOx (x = 1.5 to 2.0) is more preferable, and the stoichiometric composition ratio (for example, SiOx (x = 1.7 to 2.0)) is preferable. Further preferred. By forming the SiOx layer or region with a composition close to the stoichiometry in the Si-containing layer in this way, a dense network rich in barrier properties can be formed, thereby preventing permeation of moisture, gas, etc. The conductive layer can be prevented from being rusted.

  The formation method of Si content layer is not specifically limited, A conventionally well-known method is employable like a dry type and wet type. Specifically, as a dry method, for example, a vacuum film formation method such as a sputtering method, a chemical vapor deposition method (CVD) or a physical vapor deposition method (PVD), an ion plating method, a plating method (electrolytic plating, Examples thereof include electroless plating, hot stamping, coating, and surface oxidation treatment of the conductive layer. Moreover, you may combine several of these film forming methods, and can also employ | adopt an appropriate method according to the required film thickness. Of these, the sputtering method and the vacuum film forming method are preferable, and the sputtering method is particularly preferable. Thereby, it is possible to continuously produce by a roll-to-roll manufacturing method, increase production efficiency, and control the film thickness at the time of film formation. Therefore, it is possible to suppress an increase in the surface resistance value of the conductive film and to ensure adhesion. Further, it is possible to form a Si-containing layer that is thin, has a uniform film thickness, and has a concentration gradient as described above. Examples of the wet method include a wet coating method (coating method), a sol-gel method, a fine particle dispersion, and a method of applying a colloidal solution.

  The film thickness of the Si-containing layer is 1 to 10 nm. Thereby, while being able to stabilize the surface resistance value of the electroconductive film under humidification heat conditions, film peeling can be prevented and the adhesiveness of each layer can be ensured. 2-9 nm is preferable and, as for the film thickness of Si content layer, 3-8 nm is more preferable. This can prevent oxidation of the conductive layer due to gas generated from a resin film such as PET during heating, and can also improve the adhesion between each layer, providing excellent balance of humidification heat reliability and adhesion. A conductive film can be obtained. As the Si-containing layer, for example, when two or more layers are arranged adjacent to each other as in the Si layer and the SiOx layer, the total film thickness of all the layers may be within the above range. For example, as described above, even when the layer includes each region and has a concentration gradient, the thickness of the layer may be within the above range.

  When the easy-adhesion layer is formed on the resin film, the Si-containing layer can also be formed on the easy-adhesion layer. That is, a conductive film including a resin film, an easy-adhesion layer, a Si-containing layer, and a conductive layer in this order can be used. The Si-containing layer may have a single layer structure or a multilayer structure. In addition, in the case of a multilayer structure, as described above, it is also possible to configure it from SiOx having a different element ratio between Si and O of silicon oxide (SiOx).

(Conductive layer)
The conductive layer is directly formed on the Si-containing layer formed on at least one surface side of the resin film. The conductive layer preferably has an electric resistivity of 50 μΩcm or less in order to sufficiently obtain an electromagnetic wave shielding effect and a sensor function. The constituent material of the conductive layer is not particularly limited as long as it satisfies such electrical resistivity and has conductivity. For example, Cu, Al, Fe, Cr, Ti, Si, Nb, In, Zn, Metals such as Sn, Au, Ag, Co, Cr, Ni, Pb, Pd, Pt, W, Zr, Ta, Hf, Mo, Mn, Mg, and V are preferably used. Moreover, the thing containing 2 or more types of these metals, the alloy which has these metals as a main component, etc. can be used. Among these metals, Cu and Al are preferably included from the viewpoint of high conductivity that contributes to electromagnetic wave shielding characteristics and sensor function and relatively low cost. In particular, from the viewpoint of cost performance and production efficiency, it is preferable to contain Cu, but elements other than Cu may be contained to the extent of impurities. Thereby, since the electrical resistivity is sufficiently small and the conductivity is high, the electromagnetic wave shielding characteristics and the sensor function can be improved.

  The formation method of a conductive layer is not specifically limited, A conventionally well-known method is employable. Specifically, for example, from the viewpoint of film thickness uniformity and film formation efficiency, vacuum film formation methods such as sputtering, chemical vapor deposition (CVD), and physical vapor deposition (PVD), and ion plating are used. The film is preferably formed by a plating method, a plating method (electrolytic plating, electroless plating), a hot stamp method, a coating method, or the like. Moreover, you may combine several of these film forming methods, and can also employ | adopt an appropriate method according to the required film thickness. Of these, the sputtering method and the vacuum film forming method are preferable, and the sputtering method is particularly preferable. Thereby, it is possible to continuously produce by the roll-to-roll manufacturing method, increase the production efficiency, and control the film thickness at the time of film formation, so that an increase in the surface resistance value of the conductive film can be suppressed. In addition, a dense conductive layer that is thin, has a uniform thickness, and can be formed.

  The thickness of the conductive layer is preferably 50 to 500 nm, more preferably 70 to 400 nm, and still more preferably 80 to 300 nm. If the thickness of the conductive layer exceeds 500 nm, curling of the conductive film after heating is likely to occur, and if it is less than 50 nm, the surface resistance value of the conductive film tends to increase under humidified heat conditions, which is the target. Humidification heat reliability is not obtained. Therefore, when it is within the above range, the surface resistance value of the conductive film at the time of humidification heat reliability evaluation can be sufficiently reduced, and an increase in the surface resistance value under humidification heat conditions can be suppressed. Further, the production efficiency at the time of film formation increases, the integrated heat amount at the time of film formation decreases, and heat wrinkles are less likely to occur on the film.

(Protective layer)
The protective layer can be formed, for example, on the outermost surface side (the side opposite to the resin film substrate) of the conductive layer in order to prevent the conductive layer from being naturally oxidized under the influence of oxygen in the atmosphere. . Forming the protective layer is more advantageous in obtaining the rust prevention effect of the present invention. The protective layer is not particularly limited as long as it exhibits the effect of preventing rust of the conductive layer, but is preferably a metal that can be sputtered, such as Ni, Cu, Ti, Si, Zn, Sn, Cr, Fe, indium, gallium, antimony, zirconium. Any one or more metals selected from the group consisting of magnesium, aluminum, gold, silver, palladium, and tungsten, or oxides thereof are used. Ni, Cu, and Ti are hardly corroded because they form a passive layer, Si is difficult to corrode because of improved corrosion resistance, and Zn and Cr are metals that are difficult to corrode because they form a dense oxide film on the surface. preferable.

  As a material for the protective layer, an alloy composed of two kinds of metals can be used from the viewpoint of ensuring adhesion with the conductive layer and surely preventing rust of the conductive layer, but composed of three or more kinds of metals. Alloys are preferred. Examples of the alloy composed of three or more kinds of alloys include Ni—Cu—Ti, Ni—Cu—Fe, and Ni—Cu—Cr. From the viewpoint of rust prevention function and production efficiency, Ni—Cu—Ti is preferable. preferable. In addition, it is preferable that it is an alloy containing a conductive layer from a viewpoint of ensuring adhesiveness with a conductive layer. Thereby, the oxidation of the conductive layer can be surely prevented.

  Examples of the material for the protective layer include indium-doped tin oxide (ITO), tin oxide containing antimony (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), and indium-doped zinc oxide ( IZO) may be included. In addition to suppressing an increase in the initial surface resistance value of the conductive film, it is possible to suppress an increase in the surface resistance value under humidified heat conditions and to optimize the stabilization of the surface resistance value, which is preferable.

  The metal oxide is preferably an oxide such as SiOx (x = 1.0 to 2.0), copper oxide, silver oxide, titanium oxide, etc., from the viewpoint of stabilizing the surface resistance value of the conductive film. SiOx (x = 1.0 to 2.0) is particularly preferable. Thereby, a conductive layer becomes difficult to be corroded. In addition, it is also possible to bring about a rust prevention effect by forming a resin layer such as an acrylic resin or an epoxy resin on the conductive layer instead of the aforementioned metal, alloy, oxide or the like. The Si-containing layer and the protective layer may be the same material or different materials.

  1-50 nm is preferable, as for the film thickness of a protective layer, 2-30 nm is more preferable, and 3-20 nm is preferable. Thereby, since durability can be improved and oxidation can be prevented from the surface layer, an increase in the surface resistance value under humidified heat conditions can be suppressed.

(Conductive film of the present invention)
The conductive film of the present invention includes a resin film, a Si-containing layer, and a conductive layer in this order. When it has an easily bonding layer, it is preferable that a conductive film contains a resin film, an easily bonding layer, Si containing layer, and a conductive layer in this order. The conductive film preferably has an initial surface resistance value R ₁ of 0.001Ω / □ to 10.0Ω / □, more preferably 0.01Ω / □ to 3.5Ω / □, More preferably, it is 0.1Ω / □ to 1.0Ω / □. Thereby, the practical electroconductive film excellent in production efficiency can be provided.

The conductive film 65 ° C. The surface resistance value after 500hr left at 90% RH conditions _{R h} is, preferably 10 [Omega / □ or less, more preferably 3.5Ω / □ or less, 1 More preferably, it is 0.0Ω / □ or less. The lower limit of surface resistance value _{R h} after 500hr left with a conductive film 65 ° C. 90% RH conditions the is not particularly limited, it is preferably 0.001 ohm / □ or more, 0.01 Ohm / □ or more It is more preferable that it is 0.1Ω / □ or more. Moreover, by this, a practical conductive film excellent in production efficiency can be provided.

R _s (R _s = R _h / R ₁ ), which is a value obtained by dividing the surface resistance value R _h after leaving the conductive film at 65 ° C. and 90% RH for 500 hours by the initial surface resistance value R ₁ , is: It is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, and still more preferably 0.9 to 1.1. Thereby, the surface resistance value before and after humidification heat can be stabilized, and the electromagnetic wave shielding characteristics and the sensor function can be improved.

  The thickness of the conductive film of the present invention is preferably in the range of 2 to 200 μm, more preferably in the range of 10 to 100 μm, similarly to the resin film, and in the range of 20 to 60 μm. Is more preferable. Thereby, the electroconductive film itself can also be made thin and it becomes possible to suppress the thickness at the time of using for an electromagnetic wave shield sheet, a sensor, etc. Therefore, it can respond to thickness reduction of an electromagnetic wave shield sheet, a sensor, etc. Furthermore, if the thickness of the conductive film is within the above range, the mechanical strength can be sufficient while ensuring flexibility, and the film is rolled into a Si-containing layer or a conductive layer continuously. Operation to form becomes easy and production efficiency improves.

(Method for producing conductive film of the present invention)
The method for producing a conductive film of the present invention is a method for producing a conductive film including a resin film, a Si-containing layer, and a conductive layer in this order, and by performing sputtering using a Si target, The step of forming the Si-containing layer so as to contain SiOx (x = 0 to 2.0) on the film and having a thickness of 1 nm to 10 nm, wherein the step of forming the Si-containing layer is performed by sputtering. A step of forming a Si layer on the resin film without introducing oxygen into the gas; and a step of introducing oxygen into the sputtering gas to form a SiOx layer on the Si layer, and a Si-containing layer It has the process of forming a conductive layer directly on it. Thereby, while being able to stabilize the surface resistance value of the electroconductive film under humidification heat conditions, the electroconductive film which ensured the adhesiveness of a resin film and a conductive layer can be manufactured. In particular, by introducing oxygen after sputtering without introducing oxygen using a Si target, the Si-containing layer has a higher Si element ratio on the resin film side, and the conductive layer side Therefore, it is easy to have a concentration gradient in which the proportion of Si element is low, and the affinity between layers having different physical properties can be increased, which is advantageous in obtaining the effects of the present invention.

  In the step of forming the conductive layer in the present invention, it is preferable to perform sputtering without introducing oxygen into the sputtering gas using a metal target. Thereby, since it is easy to obtain a conductive layer having a sufficiently small electrical resistivity and high conductivity, the electromagnetic wave shielding characteristics can be improved and the sensor can be easily used as a sensor.

  In the step of forming the Si layer, sputtering is performed in an inert gas atmosphere without introducing oxygen into the sputtering gas. As the inert gas, argon gas, nitrogen gas, or the like can be used. Thereby, since there is no oxygen in sputtering gas, since the ratio of Si element can be raised, it is advantageous when acquiring the effect of this invention. That is, by forming a Si-rich layer in the Si-containing layer in this way, bonds and the like that do not participate in the bond are generated, and the bond with the adjacent layer can be maintained, so the resin film and the conductive layer Adhesion with can be secured. Even if an attempt is made to form a layer made of Si alone, depending on the film thickness, the composition may change to SiOx due to the influence of changes over time.

  In the step of forming the SiOx layer, oxygen is introduced into the sputtering gas and sputtering is performed on the Si layer. As a result, the SiOx layer can be formed with a composition close to the stoichiometry, and a dense network rich in barrier properties can be formed, preventing the passage of moisture, gas, etc., and preventing the conductive layer from being rusted. Can be prevented. The volume ratio of inert gas to oxygen gas is preferably inert gas: 60 to 90% by volume and oxygen gas: 10 to 40% by volume, and inert gas: 70 to 85% by volume and oxygen gas: 30 to 15% by volume. % Is more preferable.

  In the step of forming the Si-containing layer and the step of forming the conductive layer, it is preferable that the film feed speed is 0.1 to 20 m / min. Thereby, since it can adjust to a suitable film thickness, while being able to fully exhibit the antirust effect, a highly flexible electroconductive film is obtained. Moreover, production efficiency can be improved.

(Electromagnetic wave shield sheet)
The electromagnetic wave shielding sheet of the present invention uses the conductive film described above, and can be suitably used in the form of a touch panel or the like. The thickness of the electromagnetic wave shielding sheet is preferably 20 μm to 300 μm.

  Further, the shape of the electromagnetic wave shielding sheet of the present invention is not particularly limited, and the shape seen from the stacking direction (the same direction as the thickness direction of the sheet) is a square shape, a circular shape, or a triangular shape depending on the shape of the object to be installed. An appropriate shape such as a shape or a polygonal shape can be selected.

(Surface sensor)
The surface sensor of the present invention uses the conductive film described above, and a load sensor for a load sensor or a sensing area of an object, for example, an automobile, on a user interface such as a touch panel or a controller of a mobile device. It includes sensors that sense various physical quantities, including external forces applied to the outer surface and the surface of robots and dolls. The planar sensor can be suitably used in the form of a force sensor, a shield, or the like. The thickness of the planar sensor is preferably 20 μm to 300 μm.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

<Evaluation>
(1) Measurement of thickness The thickness of less than 1.0 μm was measured by observing the cross section of the conductive film using a transmission electron microscope (product name “H-7650” manufactured by Hitachi, Ltd.). The thickness of 1.0 μm or more was measured by using a film thickness meter (manufactured by Peacock, digital dial gauge DG-205). The measurement results are shown in Tables 1-2.

(2) Humidification heat reliability Conduction by change over time (measured at 120 hours, 240 hours, 500 hours at start (initial), 120 hours, 240 hours, 500 hours) by putting it in a constant temperature and humidity chamber under the conditions of a heating temperature of 65 ° C. and a humidity of 90% RH. The surface resistance value of the conductive film was measured by a four-terminal method according to JIS K7194. Resistance value variation in a moist heat conditions, to the initial surface resistance R _1, represented by the ratio of the surface resistance R _h after humidification heat _(R h _/ R _1). The measured results are shown in Table 1 and FIG.

(3) Adhesion test Based on JIS-K-5600, it evaluated by the crosscut method. With a cutter knife or the like, 11 cuts at 1 mm intervals were made on the film formation surface in vertical and horizontal directions to make a total of 100 grids, and cut into a length of about 75 mm on the grids. Cellotape (registered trademark) (trade name 610-1PK manufactured by 3M) is pasted, then the end of the tape is grasped and peeled off in the direction of 60 ° in a time of 0.5 to 1.0 seconds, and the peeled state of the conductive layer is visually observed. Confirmed and evaluated. Further, the peeling test of the conductive layer was performed again in the same manner as described above by rotating the angle of the sample by 90 ° (rotating from the vertical direction to the horizontal direction). Table 2 shows the measurement results.

○: The squares are not almost peeled off and the number of squares attached to the tape is 10 or less. ×: The squares are almost peeled off and the number of squares attached to the tape is 90 or more.

<Example 1>
(Formation of easy adhesion layer)
First, an 80-nm easy-adhesion layer on one side of a polyethylene terephthalate film (product name “TA-38T613N (MT474)”, hereinafter referred to as a PET film) manufactured by Mitsubishi Plastics Co., Ltd., which has a width of 1.085 m, a length of 2000 m, and a thickness of 38 μm. Formed.

(Sputter deposition)
Next, a long resin film having an easy-adhesion layer formed on a PET film is wound around a feed roll and placed in a sputtering apparatus. Thereafter, a high vacuum of 3.0 × 10 ⁻³ Torr is set in the sputtering apparatus. In a state where the sputtering apparatus is evacuated to a high vacuum, sputter film formation is performed while feeding the long resin film from the feed roll to the take-up roll.

(Formation of Si-containing layer)
First, in forming a Si layer to form a Si layer, while transporting a long resin film at a film feed speed of 2 m / min, 3.0 × 10 ⁻³ Torr consisting of Ar gas volume of 100 vol% In this atmosphere, a Si layer was formed on the resin film on which the easy adhesion layer was formed by reactive sputtering using a Si target so that the thickness of the Si layer was 2 nm. The film was formed in an atmosphere with a substrate temperature of 140 ° C. and a moisture pressure of 8.0 × 10 ⁻⁵ Pa. The partial pressure of water at this time was 0.05% with respect to the partial pressure of argon gas.

Next, in forming the SiOx layer by sputtering, it comprises 80% by volume of argon gas and 20% by volume of oxygen gas while conveying a long resin film at a film feed speed of 2 m / min. In an atmosphere of 0 × 10 ⁻³ Torr, a SiOx layer was formed on the Si layer by a reactive sputtering method using a Si target so that the thickness of the SiOx layer was 5 nm. The film was formed in an atmosphere with a substrate temperature of 140 ° C. and a moisture pressure of 8.0 × 10 ⁻⁵ Pa. The partial pressure of water at this time was 0.05% with respect to the partial pressure of argon gas. Furthermore, the resin film in which the Si-containing layer was formed on the winding roll was wound up.

(Formation of conductive layer (Cu layer))
Finally, the film containing the Si-containing layer formed into a roll is wound at a film feed speed of 2 m / min in an atmosphere of 3.0 × 10 ⁻³ Torr consisting of 100% by volume of Ar gas. Using the target material, a conductive layer (Cu layer) is formed on the Si-containing layer by sputtering with a sintered body DC magnetron sputtering method to a thickness of 200 nm, and the film is wound around a feed roll to form a conductive film. Produced.

<Comparative Example 1>
In Example 1, a conductive film was produced in the same manner as in Example 1 except that the Si-containing layer was not formed.

<Experimental example 1>
In Example 1, further, a protective layer having a thickness of 10 nm was formed on the Cu layer by sputtering using a sintered body DC magnetron sputtering method using a target material made of Cu—Ni—Ti to protect the outermost surface. A conductive film was produced in the same manner as in Example 1 except for having a layer.

<Experimental Examples 2-6>
In Experimental Example 1, a conductive film was prepared in the same manner as in Experimental Example 1 except that the Si-containing layer was prepared to have a film thickness as shown in Table 2.

(Results and discussion)
Table 1 and FIG. 3 show changes in the surface resistance value under humidification heat conditions. In Example 1, by forming a Si-containing layer with a predetermined thickness between the resin film and the conductive layer, the conductivity due to change over time (500 hr) under the conditions of a heating temperature of 65 ° C. and a humidity of 90% RH. The surface resistance value of the conductive film could be suppressed. This can be presumed to be because the Si-containing layer could suppress the effects of oxidation due to gas generated from the PET resin side, oxidation due to permeation of moisture or the like through the PET resin, and the like. The outermost surface side of the Cu layer (the side where the PET base material is not formed) is open without a protective layer or the like, but Cu does not form an oxide film (copper oxide) or the like. It is considered that once the oxide film is formed, it is difficult to oxidize further and the influence on the resistance value change rate is small because the oxide film is formed.

  On the other hand, when the Si-containing layer was not formed as in Comparative Example 1, the surface resistance value of the conductive film could not be suppressed under the humidification heat condition, and good results were not obtained. It can be inferred that this is because the Si-containing layer is not formed, and therefore the effects of oxidation due to gas generated from the PET resin side, oxidation due to the permeation of moisture, etc. through the PET resin cannot be suppressed.

  The adhesion is shown in Table 2. As the thickness of the SiOx layer was increased as in Experimental Examples 4 to 6, peeling was more likely to occur, but the adhesion was improved by forming the Si layer as in Experimental Examples 1 to 3. This is because if the Si layer is not formed, the greater the film thickness, the easier it is to peel off due to stress, but the formation of the Si layer can increase the affinity with the SiOx layer and adjust the stress balance. It is done. In addition, although Experimental Examples 1-6 use the electroconductive film which formed the protective layer on the conductive layer, even if there is no outermost protective layer, it is thought that the same result is obtained. Moreover, it is thought that the adhesiveness after humidification heat shows the same tendency as Experimental Examples 1-6.

DESCRIPTION OF SYMBOLS 1 Resin film 2 Si content layer 21 Si layer 22 SiOx layer 3 Conductive layer

Claims (10)

A conductive film including a resin film, a Si-containing layer, and a conductive layer in this order,
The Si-containing layer and the conductive layer are in direct contact,
The Si-containing layer contains SiOx (x = 0 to 2.0),
The conductive film having a thickness of the Si-containing layer of 1 nm to 10 nm.   The conductive film according to claim 1, wherein the Si-containing layer has a region having a lower oxygen concentration than a surface in contact with the conductive layer on the surface side of the resin film.   The conductive film according to claim 1, wherein the conductive layer contains copper.   The conductive film according to claim 1, wherein the conductive layer has a thickness of 50 nm to 500 nm.   The conductive film according to claim 1, wherein the resin film has an easy-adhesion layer on an outermost surface, and the easy-adhesion layer and the Si-containing layer are in direct contact with each other.   The said resin film is a conductive film of any one of Claims 1-5 containing a polyester-type resin.   The electromagnetic wave shielding sheet containing the electroconductive film of any one of Claims 1-6.   A planar sensor comprising the conductive film according to claim 1. A method for producing a conductive film comprising a resin film, a Si-containing layer, and a conductive layer in this order,
A step of forming a Si-containing layer so as to contain SiOx (x = 0 to 2.0) on the resin film and to have a thickness of 1 nm to 10 nm by performing sputtering using a Si target,
Here, the step of forming the Si-containing layer includes a step of forming a Si layer on the resin film without introducing oxygen into the sputtering gas, and a step of introducing oxygen into the sputtering gas, The manufacturing method of the electroconductive film which includes the process of forming a SiOx layer in this, and having the process of forming a conductive layer directly on Si containing layer.   The method for producing a conductive film according to claim 9, wherein in the step of forming the conductive layer, sputtering is performed using a metal target without introducing oxygen into the sputtering gas.

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