Conductive film

Abstract

Provided is a conductive film which can be used in a wide range of applications. The conductive film includes a resin and a conductive filler dispersed in the resin. The conductive film has an oxygen transmission rate of 8000 [cm < 3 > / (m < 2 >. 24 h. Atm)] or less.

Description

Technical Field

[0001] The present invention relates to a conductive film. Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2019-179732 (Patent Document 1) discloses a conductive film. The conductive film contains a crystalline olefin resin, a thermoplastic elastomer, and a conductive filler. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-179732 Summary of the Invention Problems to be Solved by the Invention

[0004] As in the conductive film disclosed in Patent Document 1 above, from the viewpoints of moldability and chemical resistance, etc., a resin is sometimes included in the conductive film. In addition, in order to improve the conductivity of the conductive film, a relatively large amount of a conductive filler needs to be included in the conductive film. However, a conductive film containing a resin and a relatively large amount of a conductive filler tends to become brittle, the airtightness and / or liquid tightness decreases, and the property of blocking the permeation of a fluid (hereinafter sometimes referred to as barrier property) decreases. As a result, the use of such a conductive film is restricted.

[0005] The present invention has been completed to solve such problems, and an object thereof is to provide a conductive film that can be used for a wide range of applications. Means for Solving the Problems

[0006] The conductive film according to one aspect of the present invention includes: a resin; and a conductive filler dispersed in the resin, and the oxygen transmission rate is 8000 [cm 3 / (m 2 ·24 h·atm)] or less.

[0007] In this conductive film, the oxygen transmission rate is 8000 [cm 3 / (m 2 ·24 h·atm)] or less. Therefore, this conductive film can improve the barrier property of blocking the permeation of a fluid such as a gas or a liquid, and can be used for a wide range of applications.

[0008] This conductive film includes: a first resin layer in which a first conductive filler is dispersed; and a second resin layer formed on the first resin layer and in which a second conductive filler is dispersed.

[0009] In this conductive film, the volume percentage concentration of the first conductive filler in the first resin layer and the volume percentage concentration of the second conductive filler in the second resin layer may be 6 vol% or more.

[0010] In the conductive film, since the concentration of the conductive filler is high enough, the resistance value of the conductive film can be reduced.

[0011] Another aspect of the method for manufacturing a conductive film according to the present invention is the method for manufacturing the above-mentioned conductive film, including the following steps: a step of manufacturing a molten material by heating and melting a material containing a resin and a conductive filler; a step of extruding the molten material from a die through a die lip of the die; and a step of receiving the molten material extruded from the die through the lip by a cooling roll in a winding manner, and cooling the molten material by contacting with the cooling roll to manufacture a conductive film. The temperature difference between the die lip and the cooling roll is 250°C or less.

[0012] In the method for manufacturing the conductive film, the temperature difference between the temperature of the die lip through which the molten material extruded from the die passes and the temperature of the cooling roll with which the molten material contacts after passing through the die lip is small. As a result, according to this manufacturing method, the molten material can be gradually cooled, and a conductive film with high crystallinity can be manufactured. Therefore, the conductive film manufactured by this manufacturing method can improve the barrier property against the permeation of fluids such as gases or liquids, and can be used for a wide range of applications. Advantages of the Invention

[0013] According to the present invention, a conductive film that can be used for a wide range of applications can be provided. Description of the Drawings

[0014] Figure 1 is a diagram schematically showing a cross section of the conductive film of the first embodiment. Figure 2 is a diagram schematically showing the configuration of a manufacturing apparatus for the conductive film of the first embodiment. Figure 3 is a diagram schematically showing a cross section of the conductive film of the second embodiment. Detailed Description of the Invention

[0015] Hereinafter, several embodiments of one aspect of the present invention will be described in detail with reference to the drawings. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. In addition, for easy understanding, each drawing schematically depicts the object with appropriate omissions or exaggerations.

[0016] [1. First Embodiment] <1-1. Configuration of the Conductive Film> Figure 1It is a diagram schematically showing a cross-section of the conductive film 10 of the first embodiment. The conductive film 10 is used, for example, as a charging film or a static-eliminating film for copiers, printers, etc.; various functional films for other electrical and electronic devices and components. In addition, surface processing such as corona, plasma, coating, or sputtering can be performed on the conductive film 10, or it can be not performed. The thickness of the conductive film 10 is, for example, 25 μm or more and 100 μm or less.

[0017] The conductive film 10 contains a resin and conductive fillers dispersed in the resin. In addition, a part or all of additives such as a dispersant, an antioxidant, an anti-blocking agent, and an anti-ultraviolet agent can be further dispersed in the resin.

[0018] As Figure 1 shown, the conductive film 10 of the first embodiment is a multilayer film. The conductive film 10 includes a first resin layer 101 and a second resin layer 102, and these layers 101 and 102 are laminated in sequence. The second resin layer 102 is formed on the first resin layer 101. One of the surface of the second resin layer 102 on the side opposite to the first resin layer 101 and the surface of the first resin layer 101 on the side opposite to the second resin layer 102 forms the surface of the conductive film 10, and the other forms the back surface. The first conductive filler 111 is dispersed in the first resin layer 101, and the second conductive filler 112 is dispersed in the second resin layer 102.

[0019] In the first resin layer 101, only one kind of resin can be included, or two or more kinds of resins can be mixed. Similarly, in the second resin layer 102, only one kind of resin can be included, or two or more kinds of resins can be mixed. In addition, in the first resin layer 101, only one kind of conductive filler can be included, or two or more kinds of conductive fillers can be mixed. Similarly, in the second resin layer 102, only one kind of conductive filler can be included, or two or more kinds of conductive fillers can be mixed. The kind or its mixture ratio of the resin contained in the first resin layer 101 and the kind or its mixture ratio of the resin contained in the second resin layer 102 can be the same or different. In addition, the kind or its mixture ratio of the first conductive filler 111 contained in the first resin layer 101 and the kind or its mixture ratio of the second conductive filler 112 contained in the second resin layer 102 can be the same or different.

[0020] Examples of the resin contained as a base material in the first resin layer 101 and the second resin layer 102 include polyolefin resins, polyamide resins, polyester resins, and polystyrene resins. Examples of polyolefin resins include polypropylene, polyethylene, and cyclic polyolefins. Examples of polyamide resins include polyamide 6, polyamide 66, and polyhexamethylene adipamide. Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate.

[0021] Among polyolefin resins, polypropylene is preferred from the viewpoints of moisture-proof properties and mechanical strength. As examples of polypropylene, homopolypropylene, atactic polypropylene, block polypropylene, polypropylene having a long-chain branched structure, and acid-modified polypropylene can be selected.

[0022] Cyclic polyolefin (cyclic olefin resin) contains a cyclic olefin component as a copolymerization component, and there is no particular limitation as long as it is a polyolefin resin containing a cyclic olefin component in the main chain. Preferred examples of cyclic polyolefin include addition polymers of cyclic olefins or their hydrogenated products, and addition copolymers of cyclic olefins and α-olefins or their hydrogenated products. In addition, substances obtained by further grafting and / or copolymerizing an unsaturated compound having a hydrophilic group with the above polymers are included in the cyclic polyolefin.

[0023] Preferred examples of polar groups include carboxyl group, acid anhydride group, epoxy group, amino group, amide group, ester group, hydroxyl group, sulfonic acid group, phosphonyl group, and phosphino group. Examples of unsaturated compounds having a polar group include (meth)acrylic acid, maleic acid, maleic anhydride, itaconic anhydride, glycidyl (meth)acrylate, alkyl (carbon number 1 to 10) (meth)acrylate, alkyl (carbon number 1 to 10) maleate, (meth)acrylamide, and 2-hydroxyethyl (meth)acrylate.

[0024] Examples of the first conductive filler 111 and the second conductive filler 112 include conductive carbon fillers and metal-based fillers. Among the metal-based fillers, for example, metal fillers, metal oxide fillers, and conductive fillers formed by metal plating (hereinafter referred to as metal-plated fillers) are included. In these examples, the use of metal-based fillers is particularly excellent in terms of improving the microhardness of the conductive film 10 and easily suppressing the micro-destruction of the conductive film 10. On the other hand, the use of conductive carbon fillers is particularly excellent in terms of improving the adhesion at the interface between the conductive filler and the resin in which it is dispersed and easily suppressing the reduction of barrier properties due to the interface.

[0025] Examples of the conductive carbon filler include graphite, carbon black (acetylene black, Ketjen black, furnace black, channel black, thermal lamp black, etc.), carbon nanotubes, and carbon fibers. Examples of the shape of the conductive carbon filler include powder and fiber. As a particularly preferred example, powdered carbon black can be cited.

[0026] Examples of the metal filler include platinum, gold, silver, copper, SUS (stainless steel), nickel, titanium, tin, aluminum, brass, iron, and zinc. Examples of the shape of the metal filler include powder, fiber, and foil. As a particularly preferred example, powdered nickel can be cited.

[0027] Examples of the metal oxide fillers include tin oxide, indium oxide, and zinc oxide, and examples of their shapes include powders. Examples of the metal-plated fillers include fillers obtained by plating glass beads, fillers obtained by plating mica powder, fillers obtained by plating glass fibers, and fillers obtained by plating carbon fibers, and examples of their shapes include powders and fibers.

[0028] Regarding the types or their combinations of the resin and the conductive filler contained in each of the first resin layer 101 and the second resin layer 102, various combinations can be considered. Among them, as an example of a preferable combination, the following examples can be cited. That is, the first conductive filler 111 can be a conductive carbon filler (particularly powdered carbon black), and the second conductive filler 112 can be a metal-based filler (particularly powdered nickel). In addition, in this example, the resins constituting the first resin layer 101 and the second resin layer 102 can both be polyolefin resins (particularly polypropylene).

[0029] As described above, since the conductive film 10 has a resin as the base material, it is excellent in terms of moldability and chemical resistance. On the other hand, the conductivity of the conductive film 10 is imparted by the conductive filler. Therefore, from the viewpoint of improving the conductivity of the conductive film 10, the volume percentage concentration of the overall conductive filler in the conductive film 10 is preferably 6 vol% or more, more preferably 10 vol% or more, and further preferably 12 vol% or more. When such numerical conditions are satisfied, the concentration of the conductive filler can be sufficiently increased, and thus the resistance value of the conductive film 10 can be reduced. In addition, the volume percentage concentration of the overall conductive filler in the conductive film 10 is preferably 25 vol% or less.

[0030] Regarding the above numerical conditions related to the volume percentage concentration of the conductive filler, it is preferably satisfied in at least one of the plurality of resin layers constituting the conductive film 10, more preferably satisfied in a plurality of layers, and further preferably satisfied in all layers. That is, the volume percentage concentration of the first conductive filler 111 in the first resin layer 101 and the volume percentage concentration of the second conductive filler 112 in the second resin layer 102 are each preferably 6 vol% or more, more preferably 10 vol% or more, and further preferably 12 vol% or more. In addition, the volume percentage concentration of the first conductive filler 111 in the first resin layer 101 and the volume percentage concentration of the second conductive filler 112 in the second resin layer 102 are each preferably 25 vol% or less.

[0031] However, generally speaking, conductive films containing resin and a relatively large amount of conductive filler tend to become brittle, with reduced airtightness and / or liquid tightness, and reduced barrier properties. As a result, the uses of such conductive films are often limited. In this regard, the present inventor obtained the following insights through the experiments disclosed as examples below: In order to ensure sufficient barrier properties and enable the conductive film 10 to be used for a wide range of applications, it is preferable to satisfy the following conditions.

[0032] The oxygen transmission rate of the conductive film 10 is preferably 8000 [cm 3 / (m 2 ·24h·atm)] or less, more preferably 6000 [cm 3 / (m 2 ·24h·atm)] or less, further preferably 4000 [cm 3 / (m 2 ·24h·atm)] or less, more preferably 3000 [cm 3 / (m 2 ·24h·atm)] or less, further preferably 2000 [cm 3 / (m 2 ·24h·atm)] or less, more preferably 1000 [cm 3 / (m 2 ·24h·atm)] or less, further preferably 100 [cm 3 / (m 2 ·24h·atm)] or less, more preferably 50 [cm 3 / (m 2 ·24h·atm)] or less. When such numerical conditions are met, the possibility of fluid leakage through the conductive film 10 can be reduced, the airtightness and / or liquid tightness of the conductive film 10 can be improved, and sufficient barrier properties of the conductive film 10 can be ensured.

[0033] The oxygen transmission rate of the conductive film 10 is preferably 1800 [cm 3 / (m 2 ·24h·atm)] or less, more preferably 1700 [cm 3 / (m 2 ·24h·atm)] or less, further preferably 1600 [cm 3 / (m 2 ·24h·atm)] or less, more preferably 1500 [cm 3 / (m 2 ·24h·atm)] or less, further preferably 1400 [cm 3 / (m 2·24 h·atm)] Hereinafter, it is more preferably 1300 [cm 3 / (m 2 ·24 h·atm)] Hereinafter, it is further preferably 1200 [cm 3 / (m 2 ·24 h·atm)] Hereinafter. When such numerical conditions are satisfied, the possibility of fluid leakage through the conductive film 10 can be reduced, the airtightness and / or liquid tightness of the conductive film 10 can be improved, and sufficient barrier properties of the conductive film 10 can be ensured.

[0034] The surface resistivity of the conductive film 10 is preferably 6000 [Ω / sq] or less, more preferably 5000 [Ω / sq] or less, further preferably 4000 [Ω / sq] or less, more preferably 3000 [Ω / sq] or less, and further preferably 2000 [Ω / sq] or less. When such numerical conditions are satisfied, the conductive film 10 can exhibit excellent conductivity.

[0035] The yield point elongation ratio of the conductive film 10 is preferably 1.40 or less, more preferably 1.30 or less, further preferably 1.20 or less, and more preferably 1.10 or less. In addition, the yield point elongation ratio is a value obtained by dividing the yield point elongation in the MD (Machine Direction, longitudinal direction) by the yield point elongation in the TD (Traverse Direction, transverse direction).

[0036] The yield point strength of the MD (Machine Direction) of the conductive film 10 is preferably 25 [MPa] or more, more preferably 30 [MPa] or more, further preferably 35 [MPa] or more, and more preferably 40 [MPa] or more.

[0037] <1-2. Manufacturing method of conductive film> Figure 2 It is a diagram schematically showing the configuration of the manufacturing apparatus 20 of the conductive film 10. As Figure 2 shown, the manufacturing apparatus 20 includes a T-die 200, a contact roll 205, casting rolls 210, 220, and a winding roll 230.

[0038] The T-die 200 is configured to heat and melt a material containing a resin and a conductive filler to produce a molten material, and extrude the molten material. The T-die 200 includes a T-die main body 201 and raw material input parts 240, 250. An extrusion port (hereinafter referred to as a die lip) 202 is provided below the T-die main body 201. The molten material is extruded from the T-die main body 201 through the die lip 202.

[0039] The resin and the conductive filler 111, which are raw materials for forming the first resin layer 101, are put into the raw material input section 240. The resin and the conductive filler 112, which are raw materials for forming the second resin layer 102, are put into the raw material input section 250. Thus, the raw materials for forming the first resin layer 101 are heated and melted to produce the first molten material, and the raw materials for forming the second resin layer 102 are heated and melted to produce the second molten material. The T-die head body 201 co-extrudes the first molten material and the second molten material, which are composed of the raw materials input via the raw material input sections 240 and 250, through the die lips 202. Thus, the first molten material and the second molten material, which are the melts of the raw materials respectively input into the raw material input sections 240 and 250, fuse with each other to form an integrated film (molten material) in which the first molten material and the second molten material are laminated (i.e., the first resin layer 101 and the second resin layer 102 are laminated).

[0040] The casting rollers 210 and 220 are configured to cool the molten material (the laminate of the first molten material and the second molten material) simultaneously extruded from the T-die head body 201 through the die lips 202 and convey it downstream. More specifically, the molten material extruded from the die lips 202 is received in a winding manner by the uppermost upstream casting roller 210 among the plurality of casting rollers 210 and 220, which is the closest to the die lips 202. The contact roller 205 is arranged side by side with the casting roller 210 and presses the molten material wound on the casting roller 210 from the outside against the casting roller 210. Thus, the molten material is sandwiched between the contact roller 205 and the casting roller 210 and comes into firm contact with the casting roller 210. The molten material is first cooled by contacting the casting roller 210, and then is also cooled by contacting the downstream casting roller 220. The take-up roller 230 is configured to pull and wind up the molten material cooled by the casting rollers 210 and 220 at a specified speed. Through the above cooling process, the molten material solidifies to produce the conductive film 10.

[0041] The temperature of the casting roller 210 can be set, for example, to be 50°C or higher and 120°C or lower. The specified speed at which the take-up roller 230 pulls the molten material can be set, for example, to be 3 m / minute or higher and 15 m / minute or lower.

[0042] The temperature difference between the die lip 202 and the casting roll 210 is preferably 250 °C or less, more preferably 230 °C or less, still more preferably 200 °C or less, yet more preferably 180 °C or less, still more preferably 160 °C or less, yet more preferably 140 °C or less, still more preferably 120 °C or less, and most preferably 100 °C or less. According to the insights discovered by the present inventors, there is a tendency that the smaller the temperature difference between the die lip 202 and the casting roll 210, the higher the microhardness of the conductive film 10 and the lower the oxygen permeability. Therefore, when the above numerical range related to the temperature difference between the die lip 202 and the casting roll 210 is satisfied, it is easy to improve the barrier property of the conductive film 10. As a result, such a conductive film 10 can be used for a wide range of applications.

[0043] In addition, according to further investigations by the present inventors, when the above numerical range related to the temperature difference between the die lip 202 and the casting roll 210 is satisfied, the temperature difference between the die lip 202 and the casting roll 210 becomes relatively small. That is, the temperature difference between the temperature of the die lip 202 through which the molten material is extruded from the T-die head 200 and the temperature of the casting roll 210 with which the molten material first comes into contact after passing through the die lip 202 becomes relatively small. As a result, the molten material can be gradually cooled, and a conductive film 10 with a relatively high crystallinity can be manufactured. Thus, it is considered that the barrier property can be improved in the conductive film 10 manufactured under the above manufacturing conditions.

[0044] <1-3. Features> As described above, in the conductive film 10 of the first embodiment, the oxygen permeability is 8000 [cm 3 / (m 2 ·24 h·atm)] or less. Therefore, excellent barrier properties can be exhibited in the conductive film 10. As a result, the conductive film 10 can be used for a wide range of applications.

[0045] [2. Second Embodiment] Figure 3 FIG. schematically shows a cross-section of the conductive film 10A of the second embodiment. The conductive film 10A of the second embodiment is the same as the conductive film 10 of the first embodiment, and is used, for example, as a charging film or a charge-removing film for copiers, printers, etc.; various functional films for other electrical and electronic devices and components. In addition, surface treatment such as corona, plasma, coating, or sputtering can be performed on the conductive film 10A, or not. In addition, the thickness of the conductive film 10A is, for example, also 25 μm or more and 100 μm or less. Since the two embodiments are common in many aspects, the conductive film 10A of the second embodiment will be described below with reference to the description of the first embodiment.

[0046] As Figure 3As shown, the conductive film 10A is a single-layer film. The conductive film 10A has a first resin layer 101A, and a first conductive filler 111A is dispersed in the first resin layer 101A. In the first resin layer 101A, a part or all of additives such as a dispersant, an antioxidant, an anti-blocking agent, and an ultraviolet absorber may also be dispersed. In the first resin layer 101A, only one type of resin may be included, or two or more types of resins may be mixed. In addition, in the first resin layer 101A, only one type of conductive filler may be included, or two or more types of conductive fillers may be mixed.

[0047] Examples of the resin included as a base material in the first resin layer 101A may be the same as those of the first resin layer 101 and the second resin layer 102 of the first embodiment. Examples of the first conductive filler 111A may be the same as those of the first conductive filler 111 and the second conductive filler 112 of the first embodiment.

[0048] Regarding the types or their combinations of the resin and the conductive filler included in the first resin layer 101A, various combinations can be considered. Among them, as an example of a preferred combination, the following examples can be cited. That is, the first conductive filler 111A can be set as a conductive carbon filler (especially powdery carbon black). In addition, in this example, all the resins constituting the first resin layer 101A can be set as polyolefin resins (especially polypropylene or polyethylene), or all can be set as polyamide resins (especially polyamide 6).

[0049] From the viewpoint of improving conductivity, the volume percentage concentration of the conductive filler 111A in the entire conductive film 10A preferably satisfies the same numerical conditions as those of the conductive film 10 of the first embodiment.

[0050] In addition, in order to ensure sufficient barrier properties and be applicable to a wide range of uses, the oxygen transmission rate of the conductive film 10A preferably satisfies the same numerical conditions as those of the conductive film 10 of the first embodiment. In addition, for the microhardness, surface resistivity, yield point elongation ratio, and yield point strength in the MD of the conductive film 10A, they also preferably satisfy the same numerical conditions as those of the conductive film 10 of the first embodiment.

[0051] The conductive film 10A of the second embodiment can be manufactured in the same manner as the conductive film 10 of the first embodiment. That is, the step of introducing the raw material for forming the second resin layer 102 into the raw material input section 250 can be omitted, and it is sufficient to extrude the first molten material composed of the raw material for forming the first resin layer 101A introduced via the raw material input section 240 through the die lip 202. The subsequent processes are the same as those of the first embodiment. The numerical conditions related to the temperature of the setting casting roll 210, the specified speed of pulling the molten material by the winding roll 230, and the temperature difference between the die lip 202 and the casting roll 210 can be the same as those of the first embodiment.

[0052] [3. Variation Example] Several embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made as long as the gist thereof is not deviated from.

[0053] For example, in the above embodiments, the conductive film is a single-layer or two-layer film, but it is not limited thereto, and it can also be a film of three or more layers. In this example, the types and compositions of the resins and conductive fillers constituting each layer are preferably selected from the contents shown in the description of the above embodiments. In addition, in this example, various parameters (micro hardness, oxygen permeability, surface resistivity, yield point elongation ratio, and yield point strength) of the entire conductive film also preferably satisfy the same numerical range as that of the above embodiments. In addition, as such an example, the second resin layer 102 of the first embodiment can be divided into multiple layers. For example, it can be composed of multiple layers with different metal filler concentrations. Examples

[0054] [4. Examples] The examples of the present invention will be described below. In addition, the present invention is not limited to the following examples.

[0055] Use Figure 2The manufacturing apparatus 20 shown manufactured the conductive films of Examples 1 to 7 and Comparative Examples 1 and 2. More specifically, as shown in Table 1 below, in Examples 1 to 4 and 6, a first resin layer was formed by kneading powdered carbon black (CB) and polypropylene (PP). In Example 5, a first resin layer was formed by kneading powdered carbon black and polyethylene (PE). In Example 7, a first resin layer was formed by kneading powdered carbon black and polyamide 6 (nylon, Ny). In Comparative Example 1, a first resin layer was formed by kneading powdered carbon black and polymethylpentene (TPX). In Comparative Example 2, a first resin layer was formed by kneading powdered carbon black and perfluoroalkoxy ethylene copolymer resin (PFA). Further, in Examples 1 to 4, a second resin layer was formed by kneading powdered nickel and polypropylene. In addition, in Examples 1 to 7 and Comparative Examples 1 and 2, the addition amount of carbon black in the first resin layer was set to 15 vol%. In Examples 1 to 4, the addition amount of nickel in the second resin layer was set to 20 vol%. In addition, in Examples 1 to 7 and Comparative Examples 1 and 2, the thickness of the entire conductive film was set to 50 μm. In Examples 1 to 4, the ratio of the thicknesses of the first resin layer and the second resin layer was set to 3:1 in order.

[0056] When manufacturing the conductive films of Examples 1 to 7 and Comparative Examples 1 and 2, the temperature difference between the die lip 202 and the casting roll 210 was changed as shown in Table 1 below. Then, for each of the manufactured conductive films of Examples 1 to 7 and Comparative Examples 1 and 2, the oxygen permeability, microhardness, surface resistivity, yield point elongation ratio, and yield point strength in the MD direction were measured by the following method (however, the measurement of microhardness was omitted in Examples 5 to 7 and Comparative Example 1). The results are shown in Table 2.

[0057] [Table 1]

[0058] [Table 2]

[0059] From the results in Table 2, it can be seen that the conductive films of Examples 1 to 7 have a lower oxygen permeability, a higher microhardness, and a smaller yield point elongation ratio than the conductive films of Comparative Examples 1 and 2. Therefore, it can be known that the conductive films of Examples 1 to 7 can be used for a wide range of applications.

[0060] <3-1. Measurement of oxygen permeability> The oxygen permeability was measured according to ASTM D1434-75M method. The sample was cut into a size of 10 cm square, and using a gas permeability measuring device (GTR TESTER M-C1 manufactured by Toyo Seiki Seisakusho), by the differential pressure method, the oxygen permeability of the sample was measured under the conditions of an adapter of 10 cc, a set pressure of 101 kPa, and a set temperature of 23.0 °C (in Examples 1 to 4, the second resin layer side was taken as the low-pressure side).

[0061] <3-2. Measurement of Microhardness> Using the method in accordance with ISO14577-1, (in Examples 1 to 4, for the second resin layer side), the Martens hardness (HMT115) based on a Vickers indenter with an included angle between the edges of 115° was measured. Using a dynamic microhardness tester (DUH-211S manufactured by Shimadzu Corporation), the test mode was set to the indentation depth setting load, the minimum test force was set to 0.02 mN, the set depth was set to 10 μm, the load speed (test speed) was set to 1.0 mN / second, the load holding time was set to 2 seconds, different parts of 5 identical samples were measured, and the average value thereof was taken as the measured value.

[0062] <3-3. Measurement of Surface Resistivity> A test piece of 30 mm square was cut out, and the surface resistance was measured using a simple low-resistance meter Loresta AX MCP-T370 (in Examples 1 to 4, from the second resin layer side) manufactured by Nittoseiko Analytech Co., Ltd. As the probe, a PSP probe MCP-TP06P RMH112 was used. The value obtained by multiplying the resistance value (Ω) measured by the low-resistance meter by the correction factor (4.532) was taken as the surface resistivity (Ω / □).

[0063] <3-4. Measurement of Yield Point Elongation Ratio> Using the method in accordance with JIS-K-6732, the yield point elongation in the MD and TD directions was measured, and the yield point elongation ratio was calculated by dividing the yield point elongation in the MD direction by the yield point elongation in the TD direction. The sample size was a rectangle with a width of 10 mm and a length of 110 mm or more. Using AUTOGRAPH (AGS-100A type manufactured by Shimadzu Corporation), the sample was pulled under the conditions of a tensile speed of 200 mm / min, a chart speed of 200 mm / min, and a distance between the clamps of 40 mm, and the elongation at the moment of the yield point was measured.

[0064] <3-5. Measurement of Yield Point Strength> The yield point strength of MD was measured using the method in accordance with JIS-K-6732. The width of the sample size was set to 10 mm and the length was set to 110 mm or more (the length of the marked line on the sample was 40 mm ± 0 - 2). The thickness of the sample was measured at 5 points equally spaced in the length direction, and the average thickness was calculated based on the measured thickness at the 5 points. The measurement was performed using AUTOGRAPH (Shimadzu Precision Universal Testing Machine AG-X 500N), the tensile speed was set to 200 mm / min, the distance between the clamps was set to 40 mm, and the maximum strength (yield point strength) was calculated based on the output graph. Description of reference numerals:

[0065] 10, 10A: Conductive film; 20: Manufacturing apparatus; 101, 101A: First resin layer; 102: Second resin layer; 111, 111A: First conductive filler; 112: Second conductive filler; 200: T-die; 201: T-die body; 202: Die lip; 205: Contact roller; 210, 220: Casting roller; 230: Take-up roller; 240, 250: Raw material input section.

Claims

1. A conductive film, wherein, Comprising: a resin; and a conductive filler dispersed in the resin, The oxygen transmission rate is 8000 [cm 3 / (m 2 ·24 h·atm)] or less.

2. The conductive film according to claim 1, wherein the conductive film has: a first resin layer in which a first conductive filler is dispersed; and a second resin layer formed on the first resin layer and in which a second conductive filler is dispersed.

3. The conductive film according to claim 2, wherein the volume percentage concentration of the first conductive filler in the first resin layer and the volume percentage concentration of the second conductive filler in the second resin layer are 6 vol% or more.

4. A method for manufacturing a conductive film, which is the method for manufacturing the conductive film according to any one of claims 1 to 3, wherein, Including the following steps: a step of manufacturing a molten material by heating and melting a material containing the resin and the conductive filler; a step of extruding the molten material from a die through a die lip of the die; and a step of manufacturing a conductive film by receiving the molten material extruded from the die through the die lip in a winding manner by a cooling roll and cooling the molten material by contacting the cooling roll, the temperature difference between the die lip and the cooling roll being 250°C or less.

Images