Film capacitor having conductive polymer layer as electrode and method for manufacturing the same

Abstract

To provide a film capacitor which can be relatively easily manufactured and a method for manufacturing the same.SOLUTION: A plastic film capacitor includes a dielectric plastic film and a conductive polymer layer as an electrode arranged on both surfaces or one surface of the plastic film. The conductive polymer layer satisfies at least one of the following (i) and (ii); (i) the conductive polymer layer is formed of a dispersion or solution of a conductive polymer compound; and (ii) the conductive polymer layer is formed of conductive polymer compound-containing particles.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a film capacitor and a method for manufacturing the same. [Background technology]

[0002] Film capacitors having a metallized film (metallized film) formed by forming a metal vapor deposition electrode on the surface of a dielectric film are known. The vapor deposition metal is, for example, aluminum, zinc, or copper, and is formed by vacuum deposition or the like. Patent Document 1 describes a capacitor in which a vapor deposition metal electrode is provided on one side of a dielectric film, and a thermal adhesive resin with a dispersed conductive or semiconductive material is formed on the side opposite the vapor deposition surface.

[0003] BACKGROUND ART Conventionally, capacitors having a configuration in which a conductive resin film is formed on a dielectric resin film (dielectric plastic film) are known.

[0004] Patent Document 2 describes a wound or flat film capacitor having a composite film consisting of an insulating resin film, a conductive resin film polymerized on the insulating resin film, and an electrode layer covering the surface of the conductive resin film. Polypropylene or the like is described as the insulating resin film, and films made of polyaniline, polypyrrole, polythiophene, polyparaphenylene, or the like are described as the conductive resin film. The electrode layer is described as being formed by vapor deposition of gold or aluminum, or the like.

[0005] Patent Document 3 describes a capacitor including a dielectric having one side with the same surface shape as that which appears when the dielectric is adhered to the surface of an electrode metal such as a porous etched foil and the other side with the same shape as the surface of the electrode metal, and polymer conductor electrodes adhered to both sides of the dielectric. Patent Document 4 describes a polypyrrole film formed by chemical polymerization as the polymer conductor. Patent Document 4 describes an embodiment in which a polyimide film has a polypyrrole film formed by chemical polymerization on both sides.

[0006] Patent Document 5 describes a method for manufacturing a ferroelectric capacitor having a lower electrode formed on a substrate, a coating film thereon, an organic thin film thereon, and an upper electrode thereon, and describes polymer electrodes as the lower electrode and the upper electrode. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 61-194815 [Patent Document 2] Japanese Patent Application Publication No. 5-243084 [Patent Document 3] Japanese Patent Application Publication No. 9-283389 [Patent Document 4] Japanese Patent Application Publication No. 11-97277 [Patent Document 5] Japanese Patent Application Laid-Open No. 2006-203037 Summary of the Invention [Problem to be solved by the invention]

[0008] Metallized films used in conventional film capacitors are manufactured by metal vapor deposition in a vapor deposition apparatus. The vapor deposition apparatus typically has a separate winding chamber and vapor deposition chamber. Heating the metal under high vacuum promotes evaporation, resulting in a uniform deposition of the metal on the plastic film surface. This method presents several problems, including the large size and high cost of the equipment, and the need for vapor deposition, which limits the range of materials that can be used. Additionally, an additional cooling device is required to prevent deformation of the plastic film due to heating.

[0009] Furthermore, in conventional capacitors having a structure in which a conductive resin film is formed on a dielectric resin film, chemical polymerization and electrolytic polymerization are used to form the conductive resin film, which causes problems such as an increase in the number of manufacturing steps and a complicated manufacturing process.

[0010] An object of the present invention is to provide a film capacitor that can be manufactured relatively easily and a method for manufacturing the same. [Means for solving the problem]

[0011] The above-mentioned problems of the present disclosure can be solved by the following aspects of the invention of the present disclosure. <Aspect 1> The dielectric plastic film has a conductive polymer layer as an electrode disposed on one or both sides of the dielectric plastic film, A plastic film capacitor, wherein the conductive polymer layer satisfies at least one of the following (i) and (ii): (i) the conductive polymer layer is a layer formed from a dispersion or solution of a conductive polymer compound; (ii) The conductive polymer layer is a layer formed from particles containing a conductive polymer compound. <Aspect 2> 2. The plastic film capacitor according to claim 1, wherein the conductive polymer layer is a layer formed from conductive polymer compound-containing particles. <Aspect 3> The plastic film capacitor according to aspect 2, wherein the conductive polymer layer is a layer formed from conductive polymer compound-containing particles, and the conductive polymer compound-containing particles have an average particle diameter in the range of 10 to 500 nm as measured with a scanning electron microscope. <Aspect 4> 4. The plastic film capacitor according to any one of aspects 1 to 3, wherein the conductive polymer layer is in direct contact with the dielectric plastic film. <Aspect 5> 5. The plastic film capacitor according to any one of aspects 1 to 4, wherein the conductive polymer layer contains a conductive polymer compound selected from polythiophene and derivatives thereof, and a dopant made of a polyanion. <Aspect 6> 6. The plastic film capacitor of any one of aspects 1 to 5, wherein the dielectric plastic film is made of a material selected from the group consisting of polyethylene, polypropylene, polystyrene, methacrylic resin, polyvinyl chloride, polyester, polyamide, polyimide, polycarbonate, polyacrylate, polyamideimide, polyetherimide, polyphenylene sulfide, polyetheretherketone, fluororesin, liquid crystal polymer, phenolic resin, epoxy resin, melamine resin, polyurethane resin, and silicone resin. <Aspect 7> A method for manufacturing a plastic film capacitor having a conductive polymer layer as an electrode disposed on a dielectric plastic film, comprising: (Ai) providing a dielectric plastic film; (A-ii) applying a dispersion or solution containing a conductive polymer compound to one or both sides of the dielectric plastic film; and (A-iii) drying the dielectric plastic film to which the dispersion or solution has been applied to form a conductive polymer layer; A method comprising: <Aspect 8> A method for manufacturing a plastic film capacitor having a conductive polymer layer as an electrode disposed on a dielectric plastic film, comprising: Providing a (Bi) dielectric plastic film; (B-ii) applying a dispersion or solution containing a conductive polymer compound onto a release substrate and drying it to form a conductive polymer film on the release substrate; (B-iii) peeling the conductive polymer film from the peeling substrate; (B-iv) disposing the conductive polymer film on one or both sides of the dielectric plastic film to form a conductive polymer layer; A method comprising: <Aspect 9> Aspect 9. The method according to aspect 7 or 8, wherein the conductive polymer compound contains a conductive polymer compound selected from polythiophene and derivatives thereof, and a dopant formed of a polyanion. <Aspect 10> The method according to any one of aspects 7 to 9, wherein the dispersion or solution containing a conductive polymer is a dispersion of conductive polymer-containing particles. [Effects of the Invention]

[0012] According to the present invention, a film capacitor that can be manufactured relatively easily and a method for manufacturing the same can be provided. In particular, according to the present invention, a film capacitor that can be manufactured relatively easily at a relatively low temperature and at a low cost and a method for manufacturing the same can be provided. Furthermore, according to the present invention, a new method for producing a film capacitor member using screen printing, inkjet printing, lithography printing, relief printing, or intaglio printing can be provided. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing the measurement setup for a single-layer film capacitor used in the examples of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0014] <<Plastic film capacitors>> The present invention relates to a plastic film capacitor, which comprises: The dielectric plastic film has a conductive polymer layer as an electrode disposed on one or both sides of the dielectric plastic film, The conductive polymer layer satisfies at least one of the following (i) and (ii): (i) The conductive polymer layer is a layer formed from a dispersion or solution of a conductive polymer compound; (ii) The conductive polymer layer is a layer formed from particles containing a conductive polymer compound.

[0015] As described above, conventional methods for manufacturing film capacitors have had problems in terms of the large number of steps, complexity, and cost.

[0016] In contrast, the plastic film capacitor of the present invention has a conductive polymer layer as a capacitor electrode on a dielectric plastic film, which is (i) a layer formed from a dispersion or solution of a conductive polymer compound and / or (ii) a layer formed from particles containing a conductive polymer compound, thereby providing a film capacitor that can be manufactured by a relatively simple method.In particular, according to the present invention, the conductive polymer layer as an electrode can be formed at room temperature and normal pressure (by coating or the like) and at a relatively low drying temperature (e.g., about 105 to 150°C), providing a film membrane that can be used as an alternative to metallized films manufactured by conventional vapor deposition in a very simple and low-cost manner.

[0017] Although not intending to be limited by theory, according to the present invention, a conductive polymer layer serving as an electrode can be produced very simply, for example, by applying a dispersion or solution containing a conductive polymer compound (particularly conductive polymer compound-containing particles) to a dielectric plastic film and drying it. This makes it possible to eliminate the equipment and / or costs associated with metal vapor deposition or chemical polymerization and electrolytic polymerization required for the production of conventional metallized films, and also to omit complicated processes.

[0018] Furthermore, according to the present invention, a dielectric plastic film having electrodes can be obtained particularly easily and in a manner suitable for various applications using techniques such as screen printing, inkjet printing, lithographic printing, letterpress printing, or intaglio printing.

[0019] The present invention will be described in more detail below. The accompanying drawings are schematic and are not necessarily drawn to scale to facilitate understanding of the invention. The drawings do not limit the present invention.

[0020] <Plastic film capacitors> A plastic film capacitor has a dielectric plastic film and conductive polymer layers as electrodes arranged on one or both sides of the dielectric plastic film.

[0021] The conductive polymer layer may be laminated on a dielectric plastic film and arranged to cover its surface. The conductive polymer layer covers at least a portion of the surface of the dielectric plastic film, thereby functioning as an electrode of the plastic film capacitor. For example, when conductive polymer layers are arranged on both sides of the dielectric plastic film, these two conductive polymer layers overlap each other in a planar view of the film capacitor, and capacitance can be formed at this overlapping portion. Furthermore, when a conductive polymer layer is arranged on one side of the dielectric plastic film, a structure in which the dielectric plastic film is sandwiched between two conductive polymer layers can be formed by, for example, stacking or winding this structure, thereby forming a capacitor.

[0022] In a preferred embodiment, the conductive polymer layer is in direct contact with the dielectric plastic film. That is, the conductive polymer layer and the dielectric plastic film are in direct contact with each other without an adhesive layer or the like. In this embodiment, when conductive polymer layers are disposed as electrodes on both sides of the dielectric plastic film, both conductive polymer layers are in direct contact with the dielectric plastic.

[0023] The plastic film capacitor may be a wound type or a flat type, particularly a laminated type in which multiple layers of dielectric plastic films each having a conductive polymer layer are combined and laminated. A wound type or flat type (particularly a laminated type) plastic film capacitor can be manufactured by a known method. For example, a wound type plastic film capacitor can be manufactured by attaching lead wires to the conductive polymer layer of the dielectric plastic film having a conductive polymer layer, winding the film, heating and pressurizing the resulting film, and then coating the film with a resin.

[0024] (dielectric plastic film) The dielectric plastic film functions as a dielectric of the plastic film capacitor. The method for providing the dielectric plastic film is not particularly limited, and the film may be prepared by, for example, a known method.

[0025] Examples of materials for the dielectric plastic film include polyethylene, polypropylene, polystyrene, methacrylic resin, polyvinyl chloride, polyester such as polyethylene terephthalate, polyamide, polyimide, polycarbonate, polyacrylate, polyamideimide, polyetherimide, polyphenylene sulfide, polyetheretherketone, fluororesin such as polytetrafluoroethylene, liquid crystal polymer, phenolic resin, epoxy resin, melamine resin, polyurethane resin, and silicone resin. These may be used alone or in combination.

[0026] In one preferred embodiment, the material of the dielectric plastic film is selected from polyethylene terephthalate, polypropylene, and polytetrafluoroethylene.

[0027] The thickness of the dielectric plastic film is not particularly limited, but may be 1 to 300 μm, particularly 5 to 200 μm.

[0028] The size of the dielectric plastic film can be appropriately selected depending on the application and is not particularly limited, but may have a width of, for example, 5 mm to 100 mm.

[0029] (Conductive polymer layer) The conductive polymer layer is a layer formed from a dispersion or solution of a conductive polymer compound and / or a layer formed from particles containing a conductive polymer compound. The thickness of the conductive polymer layer is not particularly limited, but may be 0.1 μm to 300 μm, particularly 1 μm to 200 μm.

[0030] The conductive polymer layer functions as an electrode of the plastic film capacitor. Note that embodiments that further include a conductive polymer layer that does not function as an electrode are not necessarily excluded. However, it is particularly preferred that all conductive polymer layers included in the plastic film capacitor function as electrodes of the plastic film capacitor. In particular, the plastic film capacitor does not have an electrode formed from a valve metal.

[0031] The conductive polymer layer may be, for example, a continuous, uniform thick or thin layer, or a film-like structure; alternatively, it may be an aggregate of fine particles, or a network of fine particle chains; or it may be a continuous, uniform thick or thin layer formed by the bonding or fusing of fine particles. The conductive polymer layer is particularly in the form of a fine particle layer composed of fine particles containing a conductive polymer (and optionally a dopant). Those skilled in the art can identify conductive polymer layers formed from a dispersion or solution of a conductive polymer compound. In particular, it can be distinguished from conductive polymer layers obtained by chemical polymerization. For example, chemically polymerized layers typically contain substances derived from oxidizing agents (such as iron when PEDOT is used as the conductive polymer compound), and therefore can be distinguished by compositional analysis (such as elemental analysis).

[0032] A layer formed from a dispersion or solution of a conductive polymer compound can be formed by applying the dispersion or solution to a dielectric plastic film and drying it. Alternatively, the dispersion or solution can be applied to a release substrate (e.g., a glass substrate) and dried to form a conductive polymer film, which can then be placed on a dielectric plastic film to form a conductive polymer layer.

[0033] In one preferred embodiment, the conductive polymer layer is a layer formed from conductive polymer compound-containing particles. Such a conductive polymer layer can be formed, for example, by applying a dispersion of conductive polymer compound-containing particles to a dielectric plastic film and drying it. Alternatively, the conductive polymer layer can be formed by applying a dispersion of conductive polymer compound-containing particles to a release substrate (e.g., a glass substrate) and drying it to form a conductive polymer film, and then disposing this film on a dielectric plastic film to form a conductive polymer layer.

[0034] In particular, the conductive polymer compound-containing particles may connect to each other in directions horizontal and vertical to the plane of the dielectric plastic film, or even bond and fuse to each other, thereby forming a conductive polymer layer that can function as an electrode of a capacitor.

[0035] (void) The conductive polymer layer may have voids within the range that the layer maintains its function as an electrode. The voids can be formed between the conductive polymer compound-containing particles.

[0036] The conductive polymer layer is 10 to 10 10 The surface resistance may be Ω / sq. This resistance can be measured using a surface resistance meter.

[0037] (Conductive polymer compound) The conductive polymer (particularly, conductive polymer-containing particles) contain a conductive polymer and an optional dopant. This is particularly a fine particle composed of a conductive polymer and a dopant.

[0038] The conductive polymer layer may contain conductive polymer compound-containing particles. When the conductive polymer layer contains conductive polymer compound-containing particles, the particles may have an average particle diameter of 10 to 500 nm, or even 20 to 400 nm, particularly 30 to 300 nm, 50 to 200 nm, or even 60 to 150 nm, when observed with a scanning electron microscope (SEM). The particles may have an average particle diameter of 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, or 90 nm or more, and / or an average particle diameter of 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, or 150 nm or less. This average particle diameter can be obtained by measuring the diameters of 30 or more particles in an image of the conductive polymer layer obtained with a scanning electron microscope and calculating the average value. It is preferable that each particle in the SEM image has a separate particle shape, but if the shape of each particle can be distinguished or estimated, it may be partially fused with other particles.

[0039] In one embodiment, the conductive polymer layer is a layer formed from conductive polymer compound-containing particles, and contains conductive polymer compound-containing particles having an average particle size in the range of 10 to 500 nm when observed with a scanning electron microscope.

[0040] (Conductive polymer compound) The conductive polymer compound may be at least one selected from polythiophene, polypyrrole, polyaniline, and derivatives thereof. The conductive polymer compound may be at least one of these. Preferably, the conductive polymer compound is a polymer of PEDOT or a derivative thereof. A particularly preferred conductive polymer compound is polyethylenedioxythiophene (PEDOT) (particularly poly(3,4-ethylenedioxythiophene)).

[0041] (dopant) The conductive polymer compound (particularly, conductive polymer compound-containing particles) preferably further contains a dopant. In particular, the use of a dopant made of polyaniline improves the adhesion between particles and / or the adhesion of the conductive polymer layer to a dielectric plastic film, thereby ensuring good integrity of the conductive polymer layer as an electrode.

[0042] Specific examples of dopants include aromatic sulfonic acids such as benzenesulfonic acid or its derivatives, naphthalenesulfonic acid or its derivatives, and anthraquinonesulfonic acid or its derivatives; polymeric sulfonic acids such as polystyrenesulfonic acid (PSS), sulfonated polyester, phenolsulfonic acid novolac resin, and copolymers of styrenesulfonic acid and non-sulfonic acid monomers (methacrylic acid esters, acrylic acid esters, unsaturated hydrocarbon-containing alkoxysilane compounds, or their hydrolysates); and chain sulfones such as methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and butanesulfonic acid. These may be used alone or in combination of two or more.

[0043] A preferred dopant is polystyrene sulfonic acid (PSS).

[0044] The weight-average molecular weight of polystyrene sulfonic acid (PSS) may be 10,000 to 1,000,000. The weight-average molecular weight can be measured by gel chromatography.

[0045] In particular, when polystyrene sulfonic acid (PSS) having a weight-average molecular weight of 10,000 to 150,000 (or even 30,000 to 100,000) is used, the effect of improving the adhesion between conductive polymer compound-containing particles and / or the adhesion of the conductive polymer layer to the dielectric plastic film may be particularly good.

[0046] In one embodiment, the conductive polymer layer contains a conductive polymer compound selected from polythiophene and its derivatives, and a dopant composed of a polyanion. In this case, the conductive polymer layer may be a layer formed from particles containing a conductive polymer compound selected from polythiophene and its derivatives, and a dopant composed of a polyanion.

[0047] In a particularly preferred embodiment, the conductive polymer layer contains PEDOT and PSS (particularly conductive polymer compound-containing particles composed of PEDOT and PSS), which allows for a conductive polymer layer having a more stable thickness to be obtained.

[0048] The content of the conductive polymer compound in the conductive polymer layer (or the total content of the conductive polymer compound and the dopant) may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, and particularly may be 100% by mass. In particular, the conductive polymer layer is composed of a conductive polymer compound selected from polythiophene and its derivatives and a dopant made of a polyanion.

[0049] The method for producing the plastic film capacitor of the present invention is not particularly limited, but it can be preferably produced by the following production methods (Method A and Method B) according to the present invention.

[0050] <<Plastic Film Capacitor Manufacturing Method (Method A: Direct Application Method)>> The present disclosure includes a method for manufacturing a plastic film capacitor having a conductive polymer layer as an electrode disposed on a dielectric plastic film, the method being suitable for manufacturing the plastic film capacitor according to the present invention, and comprising the following steps: (Ai) providing a dielectric plastic film (film providing step); (A-ii) applying a dispersion or solution containing a conductive polymer compound to both sides or one side of a dielectric plastic film (application step); (A-iii) Drying the dielectric plastic film to which the dispersion or solution has been applied to form a conductive polymer layer (drying step).

[0051] For details of each element constituting this manufacturing method (e.g., dielectric plastic film, conductive polymer compound, conductive polymer compound-containing particles, dopant, conductive polymer layer, etc.), please refer to the description of the plastic film capacitor according to the present invention above.

[0052] <Film provision process (Ai)> In the film providing step, a dielectric plastic film is provided, which may be cut to an appropriate size.

[0053] <Applicable process (A-ii)> In the application step, a dispersion or solution containing a conductive polymer compound is applied to one or both sides of the dielectric plastic film.

[0054] The dispersion or solution may be applied by, for example, coating or immersion, particularly by coating. The method for applying the dispersion or solution is not particularly limited, but may be a known method such as brush coating or spin coating.

[0055] In one embodiment, the dispersion is applied by screen printing, inkjet printing, lithographic printing, letterpress printing, or intaglio printing.

[0056] (Dispersion or solution) The dispersion or solution containing a conductive polymer compound contains a conductive polymer compound (particularly, particles containing a conductive polymer compound) and a dispersion medium or solvent. The dispersion or solution containing a conductive polymer compound may particularly be a dispersion of particles containing a conductive polymer compound. The solution of the conductive polymer compound may be a self-doping solution (particularly, an aqueous solution) in which the conductive polymer compound is dissolved.

[0057] The content of the conductive polymer compound-containing particles in the dispersion or solution may be 0.1 to 5% by mass, and preferably 0.5 to 3% by mass.

[0058] (Dispersion medium / solvent) As the dispersion medium or solvent, for example, water, protic solvents such as alcohols (for example, methanol, ethanol, 1-propanol, butanol), and mixtures thereof can be used.

[0059] (Particles containing conductive polymer compound) In a particularly preferred embodiment, a dispersion containing conductive polymer-containing particles is used as the dispersion or solution containing a conductive polymer, and the particles contain PEDOT and PSS. In this case, a conductive polymer layer having a more stable thickness can be obtained.

[0060] (Method for producing a dispersion of conductive polymer compound-containing particles) The method for preparing the dispersion or solution of the conductive polymer compound is not particularly limited, and may be carried out according to a conventional method. As a specific example, a dispersion of PEDOT / PSS fine particles can be prepared according to the following preparation procedures (a) to (e): (a) Ethylenedioxythiophene (EDOT) monomer and polystyrene sulfonic acid (PSS) are used to prepare a PEDOT / PSS microparticle dispersion. (b) Removing excess cationic and / or anionic components by ion exchange treatment. (c) The microparticulation treatment is carried out using a rotary homogenizer or an ultrasonic homogenizer. (d) Adjust the pH to 2 to 5 by neutralization treatment. (e) Adding a high-boiling point compound to the PEDOT / PSS nanoparticle dispersion may improve conductivity.

[0061] (additives) The dispersion or solution of the conductive polymer compound may further contain an organic solvent having a boiling point or decomposition temperature of 150° C. or higher as an additive.

[0062] Examples of organic solvents having a boiling point or decomposition temperature of 150° C. or higher include glycerin, diglycerin, and polyglycerin, glycol compounds such as ethylene glycol, diethylene glycol, and other polyethylene glycols, and derivatives thereof, γ-butyrolactone, butanediol, dimethyl sulfoxide, sulfolane, N-methylpyrrolidone, dimethyl sulfolane, and polyethylene glycol, and derivatives thereof. These may be used alone or in combination of two or more.

[0063] When the dispersion or solution of the conductive polymer compound contains an organic solvent having a boiling point or decomposition temperature of 150°C or higher, the content of the organic solvent in the dispersion or solution of the conductive polymer compound-containing particles may be 1 to 30% by mass, particularly 2 to 20% by mass, or even 3 to 15% by mass.

[0064] The conductivity of the conductive polymer compound can be further improved by using an organic solvent with a boiling point or decomposition temperature of 150°C or higher. In this case, the capacitor characteristics may also be improved, resulting in a low ESR (low resistance) and high capacitance, and the improved conductivity may also have the effect of delaying degradation (extending life). While not intending to be limited by theory, it is believed that when an additive is added to a conductive polymer-containing solution, it is absorbed into the fine particles of the conductive polymer compound, promoting the formation of an array structure of the conductive polymer compound, and resulting in improved conductivity.

[0065] The dispersion or solution of the conductive polymer compound may contain a surfactant, which may improve the adhesion between the dielectric plastic film and the conductive polymer layer.

[0066] <Drying process (A-iii)> In the drying step, the dielectric plastic film to which the dispersion or solution has been applied is dried to form a conductive polymer layer on the dielectric plastic film. The dispersion medium or solvent is removed by the drying treatment, and a conductive polymer layer is formed. The application of the dispersion or solution and the drying treatment may be performed multiple times.

[0067] Drying conditions can be appropriately set depending on the composition of the dispersion or solution and the type of dispersion medium or solvent, etc. For example, drying may be carried out at a temperature of 105 to 150° C. for 1 minute to 1 hour.

[0068] <<Plastic Film Capacitor Manufacturing Method (Method B: Film Formation Method)>> The present disclosure also includes another method for manufacturing a plastic film capacitor having a conductive polymer layer as an electrode disposed on a dielectric plastic film, which is also suitable for manufacturing the plastic film capacitor according to the present invention, and includes the following steps: (Bi) Providing a dielectric plastic film (film providing step); (B-ii) applying a dispersion or solution containing a conductive polymer compound onto a release substrate and drying it to form a conductive polymer film on the release substrate (conductive polymer film forming step); (B-iii) peeling the conductive polymer film from the peeling substrate (peeling step); (B-iv) Placing a conductive polymer film on one or both sides of a dielectric plastic film to form a conductive polymer layer (placing step).

[0069] For details of each element constituting this manufacturing method (e.g., dielectric plastic film, conductive polymer compound, conductive polymer compound-containing particles, dopant, conductive polymer layer, etc.), please refer to the description of the plastic film capacitor according to the present invention above.

[0070] <Film provision process (Bi)> In the film providing step, a dielectric plastic film is provided. For details of this step, please refer to the above description of the "film providing step (Ai)."

[0071] <Conductive polymer film formation process (B-ii)> In the conductive polymer film forming step, a dispersion or solution containing a conductive polymer compound (particularly conductive polymer compound-containing particles) is applied to a release substrate and then dried to form a conductive polymer film on the release substrate. For this step, the descriptions of the above "applying step (A-ii)" and "drying step (A-iii)" can be referred to, except that a release substrate is used instead of a dielectric plastic film as the target for applying the dispersion or solution.

[0072] (Removal substrate) The substrate for release is not particularly limited as long as it has sufficient releasability for the conductive polymer film to be formed, and examples of the substrate for release include glass substrates.

[0073] <Peeling process (B-iii)> In the peeling step, the conductive polymer film is peeled off from the peeling substrate, and the peeling treatment can be carried out, for example, by immersing the peeling substrate having the conductive polymer film obtained in the conductive polymer film-forming step in an appropriate liquid (for example, water).

[0074] <Placement process (B-iv)> In the disposition step, the conductive polymer film obtained as described above is disposed on one or both sides of a dielectric plastic film to form a conductive polymer layer. The conductive polymer film disposed on one or both sides of the dielectric plastic film becomes the conductive polymer layer that functions as an electrode of the capacitor.

[0075] <Post-process> In the above-described manufacturing methods (Methods A and B) of the plastic film capacitor according to the present invention, the dielectric plastic film having a conductive polymer layer as an electrode may be further processed. For example, a wound or flat plastic film capacitor may be manufactured according to a known method. More specifically, for example, a wound plastic film capacitor can be manufactured by attaching a lead wire to the conductive polymer layer of the above-described dielectric plastic film having a conductive polymer layer, winding the conductive polymer layer, heating and pressurizing the resultant, and then coating the resultant with a resin. [Example]

[0076] The present invention will be described in more detail below with reference to examples, which are illustrative embodiments of the present invention and are not intended to limit the present invention.

[0077] <<Examples 1 to 5>> In Examples 1 to 5, various dielectric plastic films and conductive polymer films prepared using a dispersion of particles containing a conductive polymer compound were used to manufacture single-layer film capacitors in which conductive polymer layers serving as electrodes were arranged on both sides of a dielectric plastic film.

[0078] Example 1 (Manufacturing of single layer film capacitors) In Example 1, a polypropylene film (PP film, length x width = 30 mm x 30 mm) having a thickness of 40 μm was used as the dielectric plastic film.

[0079] A dispersion liquid containing particles composed of PEDOT as a conductive polymer compound and PSS as a dopant (dispersion medium: water, containing 2% by weight of PEDOT and PSS in total, and 15% by weight of glycerin as an additive) was applied to a glass substrate as a peeling substrate and dried, thereby forming a conductive polymer film (length x width = 30 mm x 20 mm, 150 μm thick) made of the conductive polymer compound-containing particles on the glass substrate as a peeling substrate.

[0080] The obtained conductive polymer films were then placed on both sides of the dielectric plastic film made of PP, thereby forming a dielectric plastic film having conductive polymer layers as electrodes on both sides, and thus a single-layer film capacitor was produced.

[0081] This single-layer film capacitor was constructed so that when viewed perpendicular to the plane of the capacitor, the overlapping area of ​​the two conductive polymer films (conductive polymer layers) placed on both sides of the dielectric plastic film was 20 mm x 20 mm.

[0082] (Measurement and evaluation of electrical properties) Lead wires were connected to both conductive polymer layers of the manufactured single-layer capacitor, and the capacitance (pF) and loss factor D of the capacitor were measured at a frequency of 1 kHz using an LCR meter. The dielectric constant ε of the dielectric was also calculated from the obtained measurements. The results are shown in Table 1 below.

[0083] 1 is a cross-sectional schematic diagram showing the configuration during measurement of the single-layer film capacitor according to Example 1. The single-layer film capacitor 100 is composed of a dielectric plastic film 10 having conductive polymer layers 20a and 20b on both sides as electrodes. Lead wires of a measuring device 30 are connected to the conductive polymer layers 20a and 20b.

[0084] <Example 2> In Example 2, a single-layer film capacitor was manufactured and measured and evaluated in the same manner as in Example 1, except that a polyethylene terephthalate (PET) film having a thickness of 25 μm was used as the dielectric plastic film.

[0085] Example 3 In Example 3, a single-layer film capacitor was manufactured and measured / evaluated in the same manner as in Example 1, except that a 100 μm thick polytetrafluoroethylene (PTFE) film (length × width = 40 mm × 30 mm) was used as the dielectric plastic film.

[0086] Example 4 In Example 4, a single-layer film capacitor was manufactured and measured and evaluated in the same manner as in Example 1, except that a polyethylene terephthalate (PET) film having a thickness of 12 μm was used as the dielectric plastic film.

[0087] <Example 5> In Example 5, a single-layer film capacitor was manufactured and measured / evaluated in the same manner as in Example 1, except that a 25 μm thick polyethylene terephthalate (PET) film was used as the dielectric plastic film and the thickness of the conductive polymer film was 75 μm.

[0088] [Table 1]

[0089] As can be seen in Table 1, when a layer formed from a conductive polymer compound-containing liquid was used as an electrode and various dielectric plastic films were used, film capacitors could be manufactured easily under relatively low-temperature manufacturing conditions at low cost. [Explanation of symbols]

[0090] 100 Single-layer film capacitor 10. Dielectric plastic film 20a, 20b Conductive polymer layer 30 Measuring Equipment

Claims

1. The dielectric plastic film has a conductive polymer layer as an electrode disposed on one or both sides of the dielectric plastic film, A plastic film capacitor, wherein the conductive polymer layer satisfies at least one of the following (i) and (ii): (i) the conductive polymer layer is a layer formed from a dispersion or solution of a conductive polymer compound; (ii) The conductive polymer layer is a layer formed from particles containing a conductive polymer compound.

2. 2. The plastic film capacitor according to claim 1, wherein the conductive polymer layer is a layer formed from particles containing a conductive polymer compound.

3. 3. The plastic film capacitor according to claim 2, wherein the conductive polymer layer is a layer formed from conductive polymer compound-containing particles, and the conductive polymer compound-containing particles have an average particle diameter in the range of 10 to 500 nm as measured with a scanning electron microscope.

4. 3. The plastic film capacitor according to claim 1, wherein the conductive polymer layer is in direct contact with the dielectric plastic film.

5. 3. The plastic film capacitor according to claim 1, wherein the conductive polymer layer contains a conductive polymer compound selected from polythiophene and derivatives thereof, and a dopant made of a polyanion.

6. 3. The plastic film capacitor according to claim 1, wherein the dielectric plastic film is made of a material selected from the group consisting of polyethylene, polypropylene, polystyrene, methacrylic resin, polyvinyl chloride, polyester, polyamide, polyimide, polycarbonate, polyacrylate, polyamideimide, polyetherimide, polyphenylene sulfide, polyetheretherketone, fluororesin, liquid crystal polymer, phenolic resin, epoxy resin, melamine resin, polyurethane resin, and silicone resin.

7. A method for manufacturing a plastic film capacitor having a conductive polymer layer as an electrode disposed on a dielectric plastic film, comprising: (A-i) providing a dielectric plastic film; (A-ii) applying a dispersion or solution containing a conductive polymer compound to both sides or one side of the dielectric plastic film; and (A-iii) drying the dielectric plastic film to which the dispersion or solution has been applied to form a conductive polymer layer; A method comprising:

8. A method for manufacturing a plastic film capacitor having a conductive polymer layer as an electrode disposed on a dielectric plastic film, comprising: (Bi) providing a dielectric plastic film; (B-ii) applying a dispersion or solution containing a conductive polymer compound onto a release substrate and drying the dispersion or solution to form a conductive polymer film on the release substrate; (B-iii) peeling the conductive polymer film from the peeling substrate; (B-iv) disposing the conductive polymer film on one or both sides of the dielectric plastic film to form a conductive polymer layer; A method comprising:

9. 9. The method according to claim 7, wherein the conductive polymer compound comprises a conductive polymer compound selected from polythiophene and derivatives thereof, and a dopant consisting of a polyanion.

10. The method according to claim 7 or 8, wherein the dispersion or solution containing the conductive polymer is a dispersion of conductive polymer-containing particles.

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