JP2021154734A - Film for film capacitor, metal layer laminated film for film capacitor, and film capacitor - Google Patents

Abstract

To provide a film for a film capacitor which has high heat resistance and self healing property, and is also excellent in productivity.SOLUTION: A film for a film capacitor has a resin layer A having a melting point of 180°C or higher and/or a glass transition temperature of 130°C or higher, and a layer B thinner than the resin layer A on at least one film outermost layer, in which an oxygen atom content of the layer B is 1.0 mass% or more.SELECTED DRAWING: None

Description

The present invention relates to a film for a film capacitor, which is a dielectric material of a film capacitor, a metal layer laminated film for a film capacitor, and a film capacitor.

In recent years, due to global environmental problems, the market for motor-driven vehicles such as hybrid vehicles (HEV) and plug-in hybrid vehicles (PHEV), or electric vehicles (EV) and fuel cell vehicles (FCV). However, with the expansion of the market for these motor-driven vehicles and motor-driven vehicles, the demand for film capacitors used in these vehicles is also increasing rapidly.

The film capacitor is a capacitor using a resin base film as a dielectric, and can obtain excellent frequency characteristics and temperature stability. Examples of the base film of this film capacitor include a polypropylene (PP) resin film, a polyester resin film such as a polyethylene terephthalate (PET) resin film and a polyethylene naphthalate (PEN) resin film, and a thermoplastic such as a polyphenylene sulfide (PPS) resin film. Examples thereof include a resin film and a polyetherimide (PEI) resin film which is an amorphous thermoplastic resin.

Among these films, a polyetherimide resin film is attracting attention as a base film (Patent Document 1). This is because when a film capacitor is used in an electric motor-driven vehicle or an electric motor-driven vehicle, it is required to have heat resistance that can withstand use in an environment of 120 ° C., but the glass transition point temperature (Tg) is 200. This is because if a base film made of a polyetherimide resin having a temperature of ℃ or higher is used, excellent electrical characteristics such as heat resistance, withstand voltage characteristics, and dielectric characteristics can be obtained.

On the other hand, a base film having excellent heat resistance such as polyetherimide or polyphenylene sulfide generally has poor self-healing (SH) properties, and has a drawback that the capacitor capacity decreases when used for a long time. was there. On the other hand, a technique for improving self-healing property by providing a coat layer on a base film is known (Patent Documents 2 and 3).

JP-A-2007-300126 JP-A-2018-163950 International Publication No. 2007/080757

However, in the prior art, in order to achieve both heat resistance and self-healing properties, a coat of polyparaxylylene-based resin, which is expensive, takes a long time to form, has poor productivity, and has a low effect of improving self-healing properties, is used. There are problems such as the fact that a silicone-based self-healing coat that produces siloxane, which may cause defective wire wires in electric circuits when dielectric breakdown occurs, is used. Therefore, in view of the background of the prior art, the present invention is intended to provide a film for a film capacitor having high heat resistance, self-healing property, and excellent productivity.

The above-mentioned problems can be solved by the following inventions. That is, the film for a film capacitor of the present invention has a resin layer A having a melting point of 180 ° C. or higher and / or a glass transition temperature of 130 ° C. or higher, and at least one outermost layer of the film has a layer B thinner than the resin layer A. However, it is a film for a film capacitor in which the oxygen atom content of the layer B is 1.0% by mass or more.

According to the present invention, it is possible to provide a film for a film capacitor which has high heat resistance and self-healing properties and is also excellent in productivity.

The film for a film capacitor of the present invention has a resin layer A having a melting point of 180 ° C. or higher and / or a glass transition temperature of 130 ° C. or higher, and at least one outermost layer of the film has a layer B thinner than the resin layer A. The oxygen atom content of the layer B is 1.0% by mass or more. Hereinafter, the film for a film capacitor of the present invention will be specifically described.

The film for a film capacitor of the present invention has a resin layer A having a melting point of 180 ° C. or higher and / or a glass transition temperature of 130 ° C. or higher. The lower limit of the melting point of the resin layer A is preferably 205 ° C., more preferably 215 ° C., and the upper limit is not particularly set, but is preferably 400 ° C., more preferably 350 ° C. The lower limit of the glass transition temperature of the resin layer A is preferably 180 ° C., more preferably 205 ° C., and the upper limit is not particularly set, but is preferably 400 ° C., more preferably 350 ° C. When the melting point and / or glass transition temperature of the resin layer A is included in the above range, insulation failure due to heat shrinkage or film rupture is less likely to occur when the film for a film capacitor is used in a high temperature environment of 120 ° C. or higher. ..

The thickness of the resin layer A of the present invention is not particularly limited, but is preferably 100 μm or less, and more preferably 10 μm or less. By setting the thickness of the resin layer A of the present invention to 100 μm or less, it becomes easy to reduce the volume of the capacitor element. The lower limit of the thickness of the resin layer A is not particularly limited, but is preferably 0.50 μm, more preferably 1.3 μm, and even more preferably 1.6 μm. By setting the thickness of the resin layer A to 0.50 μm or more, it becomes easy to increase the dielectric breakdown voltage.

The raw material used for the resin layer A of the film for film capacitors of the present invention is not particularly limited, but is, for example, polystyrene (PS) resin, polymethylpentene (PMP) resin, cyclic olefin (COP) resin, and cyclic. Polyetherketone resin such as olefin copolymer (COC) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyester resin such as polyethylene narefurate (PEN) resin, polyamide 6 (PA6) resin, polyamide 66 ( PA66) resin, polyamide 46 (PA46) resin, polyamide 4T (PA4T) resin, polyamide 6T (PA6T) resin, modified polyamide 6T (modified PA6T) resin, polyamide 9T (PA9T) resin, polyamide 10T (PA10T) resin, and polyamide Polyene resin such as 11T (PA11T) resin, polysulfone (PSU) resin, polyethersulfone (PES) resin, polysulfone resin such as polyphenylsulfone (PPSU) resin, polyphenylene sulfide (PPS) resin, polyphenylene sulfide ketone resin, polyphenylene. Polyetherene sulfide resin such as sulfide sulfone resin and polyphenylene sulfide ketone sulfone resin, polyimide (PI) resin, polyetherimide (PEI) resin, and polyimide (PI) resin such as polyamideimide (PAI) resin, polyetherketone (PEK) ) Resin, polyetheretherketone (PEEK) resin, polyetherketoneketone (PEKK) resin, polyetheretherketoneketone (PEEKK) resin, polyetherketone etherketoneketone (PEKEKK) resin and other polyaryletherketone resins, poly Tetrafluoroethylene (PTFE) resin (also called tetrafluoroethylene resin), polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) resin (also called tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin) , Tetrafluoroethylene-hexafluoropropylene copolymer (FEP) resin (also referred to as tetrafluoroethylene-hexfluoropropylene copolymer resin), tetrafluoroethylene-ethylene copolymer (ETFE) resin (tetrafluoroethylene) -Ethethylene copolymer resin), polychlorotrifluoroethylene (PCTFE) resin (also called trifluoroethylene chloride resin), poly Vinylidene fluoride (PVDE) resin (also called vinylidene fluoride resin), fluororesin such as vinylidene fluoride, tetrafluoroethylene, hexafluoropyrene copolymer resin, polyacetal resin, liquid crystal polymer (LCP) resin, polycarbonate (PC) Examples thereof include resins, polyarylate (PAR) resins, phenol resins, polyurea resins, melamine resins, epoxy resins, alkyd resins and the like. Among these, polyetherimide resin, polycarbonate resin, polyphenylene sulfide resin, polyethersulfone resin, polysulfone resin such as polyphenylsulfone resin, polyimide resin, polymethylpentene resin, and polyether, which are excellent in heat resistance at 150 ° C. It is preferable to use ether ketone resin, polyether ketone ketone resin, and polyaryl ether ketone resin, and among resins having excellent heat resistance, polyphenylene sulfide resin, polyetherimide resin, which has low dielectric adjacency and is suitable for use as a capacitor, It is more preferable to use a polyphenyl sulfone resin and a polyether sulfone resin, and it is more preferable to contain at least one of these resins in an amount of 50% by mass or more and 100% by mass or less. These resins can also use modified products, derivatives, and copolymers with other compounds. Further, it may be used alone, or two or more kinds may be mixed and used.

The resin layer A of the film for film capacitors of the present invention has an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, a lubricant, a cross-linking agent, a flame retardant, an antistatic agent, and heat resistance as long as the characteristics are not impaired. It may contain an improver, a colorant, a slip agent, an antiblocking agent, an inorganic particle, a resin particle, an inorganic compound, an organic compound and the like. It should be noted that each of these components may be used alone or in combination of a plurality of types, if necessary.

The film for a film capacitor of the present invention has a layer B thinner than the resin layer A on at least one of the outermost layers of the film. The oxygen atom content of layer B is 1.0% by mass or more. The oxygen atom content of layer B is preferably 1.5% by mass or more, more preferably 21% by mass or more, and further preferably 25% by mass or more. The upper limit of the oxygen atom content of the layer B is not particularly limited, but is preferably 50% by mass, more preferably 37% by mass, and further preferably 34% by mass. By setting the content of oxygen atoms contained in the layer B to 1.0% by mass or more, the layer B is likely to volatilize at the time of dielectric breakdown, and the self-healing property can be enhanced. By setting the content of oxygen atoms contained in layer B to 50% by mass or less, it is possible to obtain a film having low blocking property between films and excellent productivity. The oxygen atom content of layer B is 1.0% by mass or more when the total of hydrogen atoms, carbon atoms, sulfur atoms, silicon atoms, nitrogen atoms and oxygen atoms in layer B is 100% by mass. , It means that the oxygen atom in the layer B is 1.0% by mass or more. The content of silicon atom Si in layer B, which will be described later, can be interpreted in the same manner.

The thickness of the layer B of the present invention is not particularly limited, but is preferably 10 nm or more, and more preferably 50 nm or more. By setting the thickness of the layer B to 10 nm or more, it becomes easy to enhance the self-healing property. The upper limit of the thickness of the layer B is not particularly limited, but is preferably 5.0 μm, more preferably 1.0 μm, further preferably 0.50 μm, and 0.30 μm. Is particularly preferable. By setting the thickness of the layer B to 5.0 μm or less, it becomes easy to increase the dielectric breakdown voltage.

Here, the thickness of each layer can be measured by observing the cross section in the width direction-thickness direction with a field emission differential electron microscope and measuring the length thereof, and the detailed procedure will be described later. In addition, the atomic content in each layer can be determined from the atomic fraction obtained by the Rutherford backscattering / hydrogen forwardscattering analysis simultaneous measurement method (Pelletron 3SDH manufactured by National Electrostatics Corporation), and the detailed procedure will be described later. (Not only the oxygen atom content of layer B, but also the other atomic content of each layer is the same.)

The content of silicon atom Si in layer B is preferably 27% by mass or less. The upper limit of the content of silicon atom Si in layer B is more preferably 15% by mass or less, more preferably 3.0% by mass or less, still more preferably 1.0% by mass or less, and not containing silicon atom Si. Is particularly preferable. By setting the content of the silicon atom Si contained in the layer B to 27% by mass or less, the capacitor characteristics can be deteriorated by the siloxane generated at the time of dielectric breakdown.

Layer B preferably satisfies the following condition (i).
Condition (i): A value calculated from the atomic fractions of hydrogen atom H, carbon atom C, sulfur atom S, silicon atom Si, nitrogen atom N and oxygen atom O contained in layer B based on the following equation (a). XB is 0.90 or less.
Equation (a) XB = (atomic fraction of carbon atom C in layer B + atomic fraction of nitrogen atom N in layer B + atomic fraction of sulfur atom S in layer B + atomic fraction of silicon atom Si in layer B ) / (Atomic fraction of hydrogen atom H in layer B + atomic fraction of oxygen atom O in layer B)
The upper limit of XB in the condition (i) is more preferably 0.80, still more preferably 0.70, and particularly preferably 0.65. XB is the ratio of atoms that tend to transpire at the time of dielectric breakdown to atoms that tend to transpire. By setting it to 0.90 or less, the self-healing property and the reliability of the capacitor are improved. It becomes easy. The lower limit of XB is not particularly limited, but is preferably 0.050, more preferably 0.20. By setting XB to 0.050 or more, it becomes easy to increase the adhesion between the layer B and the resin layer A.

The raw material used for the layer B is not particularly limited, but for example, a resin or a low molecular weight organic compound can be used. It is preferable to use a resin from the viewpoint of adhesion to the resin layer A. The resin used for layer B is not particularly limited, but for example, polystyrene (PS) resin, polymethylpentene (PMP) resin, cyclic olefin (COP) resin, cyclic olefin copolymer (COC) resin, and the like. Polyester resin such as polyolefin resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and polyethylene narefurate (PEN) resin, polyamide 6 (PA6) resin, polyamide 66 (PA66) resin, polyamide 46 (PA46) Polyene resin such as resin, polyamide 4T (PA4T) resin, polyamide 6T (PA6T) resin, modified polyamide 6T (modified PA6T) resin, polyamide 9T (PA9T) resin, polyamide 10T (PA10T) resin, and polyamide 11T (PA11T) resin. , Polyetherketone (PES) resin, polysulfone resin such as polyphenylsulfone (PPSU) resin, polyphenylene sulfide (PPS) resin, polyphenylene sulfide ketone resin, polyphenylene sulfide sulfone resin, polyarylene sulfide resin such as polyphenylene sulfide ketone sulfone resin. , Polyetherketone (PI) resin, polyetherimide (PEI) resin, and polyimide (PI) resin such as polyamideimide (PAI) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, polyetherketone Polyetheretherketone resin such as ketone (PEKK) resin, polyetheretherketoneketone (PEEKK) resin, polyetherketone etherketoneketone (PEKEKK) resin, polytetrafluoroethylene (PTFE) resin (also referred to as tetrafluoroethylene resin). ), Polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) resin (also called tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) resin (Also referred to as ethylene tetrafluoride-propylene hexafluoride copolymer resin), tetrafluoroethylene-ethylene copolymer (ETFE) resin (also referred to as tetrafluoroethylene-ethylene copolymer resin), polychlorotrifluoroethylene (PCTFE) resin (also called ethylene trifluoride resin), polyvinylidene fluoride (PVDE) resin (also called vinylidene fluoride resin) C), fluororesins such as vinylidene fluoride, tetrafluoroethylene, hexafluoropyrene copolymer resin, polyacetal resin, liquid crystal polymer (LCP) resin, polycarbonate (PC) resin, polyarylate (PAR) resin, phenol resin, polyurea Resins, melamine resins, epoxy resins, alkyd resins, acrylic resins, polymethylmethacrylate resins (PMMA), polyurethane resins (PUs), polyurethane acrylate resins, celluloses, cellulose derivatives (eg cellulose acetate, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropyl) Methyl cellulose, etc.), petroleum resin, terpene resin, terpene phenol resin, etc. can be mentioned. Among these resins, polyethylene (PE) resin, polypropylene (PP) resin, polystyrene (PS) resin, polymethylpentene (PNP) resin, and cyclic olefin (COP) are examples of resins having a low XB value and high self-healing properties. ) Resins, polyolefin resins such as cyclic olefin copolymer (COC) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyester resin such as polyethylene narefurate (PEN) resin, epoxy resin, alkyd resin. , Acrylic resin, polymethylmethacrylate resin (PMMA), polyacetal resin, liquid crystal polymer (LCP) resin, polycarbonate (PC) resin, polyallylate (PAR) resin, phenol resin, cellulose, cellulose derivative (for example, cellulose acetate, carboxymethyl cellulose) , Hydroxyethyl cellulose, hydroxypropyl methyl cellulose, etc.), petroleum resin, terpene resin, terpene phenol resin, etc. are preferably used.

Among these raw materials, the acrylic resin can increase the heat resistance by cross-linking at the time of formation, and the epoxy resin and the cellulose derivative have high heat resistance due to the structure of the main skeleton. When a capacitor element made of a capacitor film is manufactured, it becomes easy to extend the life at a high temperature. Further, since the acrylic resin, the epoxy resin, the cellulose derivative, and the polyester resin are resins containing oxygen atoms, it is easy to increase the oxygen atom content of the layer B and enhance the self-healing property. From these points, it is more preferable that the layer B contains at least one resin among the acrylic resin, the epoxy resin, the cellulose derivative, and the polyester resin in an amount of 50% by mass or more and 100% by mass or less. As these raw materials, copolymers with modified products, derivatives, and other compounds, and resins formed by coating in the form of monomers and then polymerizing can also be used. Further, it may be used alone, or two or more kinds may be mixed and used.

In the film for a film capacitor of the present invention, the layer B contains two or more components that are incompatible with each other from the viewpoint of increasing the height of the protruding ridges on the surface on the layer B side to improve the slipperiness. Is preferable. Here, the "components that are incompatible with each other" are two components that are not uniformly mixed at the molecular level, and specifically, the phases containing the two different components as the main components are all 0.01 μm or more. In the case of forming a phase structure, it refers to the two components (whether or not they correspond to the "main component" here, the total content of the two components is 50% by mass in all the components constituting the layer B. It can be judged by whether or not it exceeds%.) For example, when three or more components are contained in the layer B, if the phase containing one component as the main component forms a phase structure of 0.01 μm or more, “two incompatible with each other”. Including the above components ”shall be satisfied. When the components constituting the layer B are 3 or more components, if 2 components satisfy the above requirements, "two or more components that are incompatible with each other" regardless of whether or not the remaining other components satisfy the above requirements. It is considered to contain the components of.

Whether or not two or more components are incompatible is determined by an electron microscope, differential scanning calorimetry (DSC), as described in, for example, Polymer Alloys and Blends, Leszek A Utracki, hanser Publishers, Munich Viema New York, P64. , And various other methods. The method of mixing two or more types of components that are incompatible with each other to increase the height of the protruding peaks is not particularly limited. For example, the particles and the resin are dispersed in a solvent to make the particles as protrusions during drying. Method of leaving, a resin having a high affinity with the material of the resin layer A and a resin having a low affinity are mixed so that the amount of the resin having a low affinity is reduced, and the resin having a low affinity is scattered on the surface on the layer B side as protrusions. By dissolving a resin having a high affinity for each solvent in two kinds of solvents having different boiling points and setting the temperature so that one solvent evaporates first at the time of drying, the remaining one Examples thereof include a method in which the resin dissolved in the solvent is later precipitated as protrusions, a method in which these are combined, and the like.

As the combination of the two components incompatible with each other used in the layer B, a combination of an acrylic resin and a cellulose derivative, a combination of a cellulose derivative and an epoxy resin, and a combination of a methacrylic resin and an acrylic resin are preferable. These can also be copolymers with modified products, derivatives, and other compounds, and resins formed by coating in the form of monomers and then polymerizing, and are compositions for forming layer B. When the resin layer A is coated with a coating liquid in which one of these raw materials is mixed in the form of a polymer and the other in the form of a monomer, the monomer is polymerized. It is preferable to form. Further, if workability is important, for example, a combination of epoxy resin and silica is also preferable.

The film for a film capacitor of the present invention preferably has a dielectric loss tangent of 2.0% or less from the viewpoint of prolonging the life when used in a capacitor. From the above viewpoint, the upper limit of the dielectric loss tangent of the film for a film capacitor is preferably 0.70%, more preferably 0.40%, and further preferably 0.30%. When the dielectric loss tangent of the film for a film capacitor is 2.0% or less, the amount of heat generated during energization when used for a film capacitor is reduced, and the life of the film capacitor is extended. The lower limit of the dielectric loss tangent of the film for a film capacitor is not particularly limited, but is preferably 0.0010%, more preferably 0.010%. For the dielectric loss tangent of the film for a film capacitor, when a resin having a low polarity is used as the resin of the resin layer A, or when a raw material having a dielectric loss tangent higher than that of the resin layer A is used as the raw material of the layer B, the dielectric loss tangent of the layer B It can be made smaller by reducing the thickness. The dielectric loss tangent referred to here refers to a value measured according to JIS C2138-2007, and a detailed measurement method thereof will be described later.

In the film for a film capacitor of the present invention, when the dynamic friction coefficient is measured between the two outermost layer surfaces, the surface having the larger dynamic friction coefficient is defined as the a surface and the surface having the smaller dynamic friction coefficient is defined as the b surface. When the coefficient of dynamic friction between the surfaces is μdaa and the coefficient of dynamic friction between the a surface and the b surface is μdab, it is preferable that μdaa> μdab and μdab ≦ 1.2. Further, the coefficient of dynamic friction between the b-planes is μdbb. The μdab preferably satisfies μdab ≦ 0.90, more preferably μdab ≦ 0.75, and particularly preferably μdab ≦ 0.60. By setting μdaa> μdab and μdab ≦ 1.2, it is possible to improve the slipperiness without lowering the capacitor characteristics. Further, by setting μdab to a low value, the workability can be further improved. The lower limit of μdab is not particularly limited, but is preferably 0.10. By setting μdab to 0.10 or more, it becomes easy to prevent unwinding when the film for a film capacitor of the present invention is used as a winding body. The coefficient of dynamic friction shall be measured at a load of 200 g, 25 ° C., and 65% RH according to JIS K 7125 (1999), and the detailed procedure will be described later.

The method for ensuring that μdaa and μdab satisfy μdaa> μdab and μdab ≦ 1.2 is not particularly limited, but a resin layer A is formed on a smooth base film or a mirror surface roll. A method of forming the layer B by including two incompatible components in the raw material can be mentioned. When μdab is high, μdab can be lowered by adjusting the mixing ratio so that the difference between the contents of the two components described above becomes small. In order to make μdaa ≤ μdab, μdab is lowered by the above method, or the smoothness of the base film or roll used to form the resin layer A is increased, and μdaa is increased to increase μdaa> μdab. Can be.

The value of μdbb is not particularly limited, but is preferably 0.10 or more, and more preferably 0.25 or more. By setting μdbb to 0.10 or more, it becomes easy to suppress winding misalignment when the film for a film capacitor of the present invention is used as a winding body. The upper limit of μdbb is not particularly limited, but is preferably 2.0, more preferably 1.5, and even more preferably 1.2. By setting the value of μdbb to 2.0 or less, it becomes easy to improve the workability.

The lower limit of μdaa is not particularly limited, but is preferably 0.10 or more, and more preferably 0.25 or more. By setting the lower limit of μdaa to 0.10 or more, it becomes easy to suppress winding misalignment when the film for a film capacitor of the present invention is used as a winding body. The upper limit of μdaa is not particularly limited, but is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less. By setting the upper limit of μda to 2.0 or less, it becomes easy to improve workability.

In the film for a film capacitor of the present invention, it is preferable that at least one outermost layer surface satisfies the load area ratio Smr1 ≧ 12% that separates the protruding peak portion and the core portion. Since Smr1 focuses on the ratio of the protruding portion, the higher the value, the more effectively the contact area when contacted with another surface can be reduced. By setting Smr1 to 12% or more, it becomes easy to improve the slipperiness of the film while keeping the breakdown voltage of the film high. The upper limit of Smr1 is not particularly limited, but is preferably 49%, more preferably 18%. By setting Smr1 to 49% or less, it becomes easy to suppress deformation of the film surface when the film for a film capacitor of the present invention is used as a wound body. Smr1 can be measured and calculated according to ISO 25178-2: 2012 and ISO 25178-3: 2012, and the detailed measurement procedure will be described later.

The method for ensuring that Smr1 on the surface of at least one outermost layer satisfies Smr1 ≥ 12% is not particularly limited, but for example, layer B is formed by including two incompatible components in the raw material. The method can be mentioned. When Smr1 is low, the mixing ratio is adjusted so that the difference between the contents of the two components is large, and the solubility parameter (so-called SP value) of the two components is small. Smr1 can be increased.

The value XA calculated from the atomic fractions of hydrogen atom H, carbon atom C, sulfur atom S, silicon atom Si, nitrogen atom N and oxygen atom O contained in the resin layer A based on the following equation (b) is It is preferable that XA> XB is satisfied with respect to XB.
Formula (b) XA = (atomic fraction of carbon atom C in resin layer A + atomic fraction of nitrogen atom N in resin layer A + atomic fraction of sulfur atom S in resin layer A + silicon atom Si in resin layer A Atomic fraction of) / (Atomic fraction of hydrogen atom H in resin layer A + Atomic fraction of oxygen atom O in resin layer A)
The higher the XA, the higher the degree of unsaturation and the tendency for the resin to have a rigid structure. Therefore, by satisfying XA> XB, it is easy to improve the self-healing property while maintaining high heat resistance. become.

The ratio of the protruding peak height Spk-a on the a-plane to the protruding peak height Spk-b on the b-plane satisfies Spk-b / Spk-a ≧ 2.0, and the protruding peak height on the b-plane and the core. It is preferable that the load area ratio Smr1-b ≥ 12% or more for separating the parts. By setting Smr1-b to 12% or more, the slipperiness of the film can be improved. The upper limit of Smr1-b is not particularly limited, but is preferably 49%. By setting Smr1-b to 49% or less, it becomes easy to suppress deformation of the film surface when the film for a film capacitor of the present invention is used as a wound body. By satisfying Spk-b / Spk-a ≧ 2.0 and Smr1-b ≧ 12%, it becomes easy to obtain a film having excellent slipperiness. Spk-a and Spk-b can be measured and calculated according to ISO 25178-2: 2012 and ISO 25178-3: 2012, and the detailed measurement procedure will be described later.

A method for ensuring that Spk-a, Spk-b, and Smr1-b on at least one outermost layer surface satisfy Spk-b / Spk-a ≥ 2.0 and Smr1-b ≥ 12% or more. The method is not particularly limited, and examples thereof include a method of forming the layer B by including two incompatible components in the raw material. When Spk-b / Spk-a is low, the difference in the contents of the two components mentioned above is increased so that the solubility parameter (so-called SP value) of the two components is increased so that Spk-b / Spk-b / Spk-a can be increased. When Smr1-b is low, the mixing ratio is adjusted so that the difference in the contents of the two components is large, or the solubility parameter (so-called SP value) of the two components is reduced. Smr1-b can be increased.

When the total thickness of the resin layer A and the layer B is T (F), the maximum valley depth Sv of the outermost layer surfaces of both the films for film capacitors of the present invention is Sv / T (F) <0.30. It is preferable to satisfy. The upper limit of Sv / T (F) is preferably 0.20 on both sides. That is, it is more preferable that Sv / T (F) ≤ 0.20. Sv / T (F) means the size of the dent with respect to the thickness of the film, and the higher the size, the easier it is for dielectric breakdown when compared with the same thickness. By setting the Sv / T (F) to less than 0.30, it becomes easy to obtain a film having high withstand voltage characteristics. Sv can be measured and calculated according to ISO 25178-2: 2012 and ISO 25178-3: 2012, and the detailed measurement procedure will be described later.

The method of setting the Sv / T (F) to less than 0.30 is not particularly limited, but for example, the resin layer A is formed on a smooth base film or a mirror surface roll, and a solution or liquid layer B is formed on the resin layer A. After coating the raw material of the above with a coater, it is dried to form a layer B. When the Sv / T (F) of the surface on the layer B side is 0.30 or more, the Sv / T (F) can be lowered by adding a leveling agent to the raw material of the layer B.

The value of the maximum valley depth Sv of both outermost layer surfaces of the film for a film capacitor of the present invention is preferably 0.10 nm or more, and more preferably 10 nm or more on each surface. By setting the maximum valley depth Sv of both outermost layer surfaces of the film for film capacitors of the present invention to 0.10 nm or more on any surface, it becomes easy to improve workability. The upper limit of the maximum valley depth Sv of both outermost layer surfaces of the film for film capacitors of the present invention is preferably 5000 nm on any surface. By setting the maximum valley depth Sv of both outermost layer surfaces of the film for film capacitors of the present invention to 5000 nm or less on any surface, it becomes easy to obtain a film having high withstand voltage characteristics.

Hereinafter, the metal layer laminated film for a film capacitor of the present invention will be described. The film for a film capacitor of the present invention is preferably a metal layer laminated film for a film capacitor having a metal layer on the surface of at least one outermost layer from the viewpoint of integration, and the resin layer A for the purpose of enhancing self-healing property. It is more preferable to use a metal layer laminated film for a film capacitor having the layers B and the metal layer in this order. Here, "having the resin layer A, the layer B, and the metal layer in this order" refers to all aspects in which the resin layer A, the layer B, and the metal layer are located in this order, and refers to the resin layer A and the layer B. It does not matter whether there is another layer between the layer B and the metal layer.

Further, the metal layer laminated film for a film capacitor of the present invention exhibits the effect of improving the slipperiness of the layer B while maintaining high withstand voltage characteristics by increasing the smoothness of the resin layer A made of a resin having high heat resistance. The layer B is provided only on one surface of the resin layer A, and the metal layer is provided on the layer B side. Of the two outermost layer surfaces, the dynamic friction coefficient measured between the same surfaces is large. When the side surface is the a-side and the smaller surface is the b-side, it is particularly preferable that the b-side is on the layer B side when viewed from the resin layer A.

The thickness of the metal layer is preferably in the range of 1 nm or more and 100 nm or less, more preferably 5 nm or more and 80 nm or less, and further preferably 10 nm or more and 50 nm or less. The surface resistance value of the metal layer is preferably in the range of 0.1 Ω / sq or more and 10 Ω / sq or less, more preferably 2 Ω / sq or more and 8 Ω / sq or less, and further preferably 3 Ω / sq or more and 6 Ω / sq or less. .. This is because when the surface resistance value of the metal layer is less than 0.1 Ω / sq, the self-healing property (also referred to as self-healing property) is lowered, which is not preferable. On the contrary, if it exceeds 10Ω / sq, the dielectric loss tangent may deteriorate.

The film for a film capacitor of the present invention is preferably used as a dielectric film for a capacitor, but is not limited to the type of the capacitor. Specifically, from the viewpoint of electrode configuration, it may be either a foil-wound capacitor or a metal vapor-deposited film capacitor, and is preferably used for an oil-immersed capacitor impregnated with insulating oil or a dry capacitor that does not use insulating oil at all. Be done. Further, from the viewpoint of shape, it may be a winding type or a laminated type. Among these, from the characteristics of the film of the present invention, it is preferable to use it as a metal vapor-deposited film capacitor containing a metal layer laminated film. As a method for forming the metal layer, for example, a vacuum deposition method, a sputtering method, an ion plating method, a plating method and the like are used. Among these methods, the vacuum vapor deposition method having excellent productivity is preferable. When the metal layer is vapor-deposited, an oil method, tape, or the like is used as the vapor deposition method. The vapor deposition pattern of the metal layer is not particularly limited, but preferred patterns include, for example, a T-margin pattern, a honeycomb pattern, a mosaic pattern, and the like.

Next, the film capacitor of the present invention will be described. The film capacitor of the present invention is made by using the metal layer laminated film for a film capacitor of the present invention. The film capacitor of the present invention shall be a part of an automobile inverter and / or converter (for example, an inverter for a hybrid electric vehicle, a converter for a hybrid electric vehicle, an inverter for an electric vehicle, a converter for an electric vehicle, etc.). Can be done.

Next, an example of a method for manufacturing a film for a film capacitor of the present invention will be described. The following example has a two-layer structure having a resin layer A and a layer B, but the film for a film capacitor of the present invention has a two-layer structure as long as it has the resin layer A and the layer B. It may have a configuration of three or more layers having layers other than the above. In the case of a configuration of three or more layers, the thickest layer having a melting point of 180 ° C. or higher and / or a glass transition temperature of 130 ° C. or higher is designated as the resin layer A.

First, as a method for forming the resin layer A, a method in which the raw material of the resin layer A is supplied to an extruder, melt-extruded from a slit-shaped mouthpiece such as a T-die, and solidified on a cooling drum or the like to form the resin layer A. Or, the raw material of the solution or liquid resin layer A is coated with a coater on a substrate film such as a polyolefin film, a polyethylene terephthalate film, a polyimide film, or a film obtained by coating them with silicone to improve releasability. Examples thereof include a method of forming the resin layer A by drying the film, a method of forming the resin layer A by casting the liquid on a casting belt, and then drying the film. Above all, from the viewpoint of improving the smoothness of the resin layer A, a method of forming the resin layer A by applying a solution or liquid raw material of the resin layer A on a base film with a coater and then drying the raw material, or a raw material. Is supplied to an extruder, melt-extruded from a slit-shaped mouthpiece such as a T-die, solidified on a cooling drum or the like to form a film, and then stretched in a uniaxial or biaxial manner to form a resin layer A. It is preferable to carry out by any of the above methods. When the resin layer A is formed on the base film, the resin layer A may or may not be peeled from the base film before the layer B is formed, but from the viewpoint of improving the transportability. Therefore, it is preferable to form the layer B without peeling.

As a method of forming the layer B on one surface of the resin layer A, a method of coating the raw material of the solution or liquid layer B on the resin layer A with a coater and then drying, or a method of applying the raw material of the layer B to the resin layer A method of vacuum deposition on A can be mentioned. From the viewpoint of increasing the height of the protrusions of the formed layer B, it is preferable to form the raw material of the solution or liquid layer B by a method of coating the resin layer A with a coater and then drying.

When the raw material of the layer B is coated on one surface of the resin layer A to form the coated surface, the coated surface of the resin layer A may be subjected to surface treatment such as corona discharge treatment in advance. By performing a surface treatment such as a corona discharge treatment, it becomes easy to improve the wettability of the coating composition on the coated surface, prevent the coating composition from repelling, and achieve a uniform coating thickness. When a metal layer is laminated on the obtained film composed of the resin layer A and the layer B, the method is not particularly limited, but it is preferable to deposit the metal on the layer B by vacuum deposition. Aluminum is preferable as the metal used for vapor deposition. At this time, other metal components such as nickel, copper, gold, silver, chromium and zinc can be vapor-deposited simultaneously or sequentially with aluminum. When the metal layer is laminated on the film composed of the resin layer A and the layer B by vapor deposition, the vapor deposition surface of the film may be subjected to surface treatment such as corona discharge treatment before vapor deposition. By performing a surface treatment such as a corona discharge treatment, the adhesion of the vapor-deposited metal to the film can be improved.

When forming the layer B, it is preferable to crosslink the components of the layer B. The method for cross-linking is not particularly limited, and examples thereof include a method in which a compound having a plurality of reaction points is used as a raw material for layer B and the cross-linking reaction is carried out by heat or ultraviolet rays. Examples of the compound having a plurality of reaction sites include an acrylate having two or more vinyl groups, an epoxy having two or more epoxy groups, and a condensate of melamine and formaldehyde. Of these, from the viewpoint of increasing the oxygen concentration of layer B and enhancing the self-healing property, it is preferable to use an acrylate having two or more vinyl groups. In order to promote the cross-linking reaction, a catalyst such as an acid or a base or an additive such as a cation initiator, an anion initiator or radical initiator is added at the time of forming the layer B according to the reactivity of the reaction site. May be good. For example, when an acrylate having two or more vinyl groups is used as a raw material for layer B, a coating liquid to which a radical initiator that generates radicals by ultraviolet rays is added is prepared, and the coating liquid is applied to the resin layer A. The cross-linking reaction can be promoted by irradiating with post-ultraviolet rays. The radical initiator is not particularly limited, but a hydroxyalkylphenone-type initiator or an aminoacetophenone-type initiator that generates radicals by ultraviolet rays can be used. By cross-linking the layer B, it becomes easy to increase the heat resistance of the film for a film capacitor of the present invention.

Hereinafter, the film for a film capacitor of the present invention will be specifically described with reference to Examples. The method for measuring the characteristic value and the method for evaluating the effect are as follows.

(1) Film thickness T (F)
The thickness of any 10 points of the film was measured using a contact type electronic micrometer (K-312A type) manufactured by Anritsu Co., Ltd. in an atmosphere of 23 ° C. and 65% RH. The arithmetic mean value of the thicknesses at the 10 points was defined as the film thickness T (F).

(2) Thickness T (A) of resin layer A, thickness T (B) of layer B
Using the microtome method, an ultrathin section having a cross section in the width direction-thickness direction of the film and having a width of 5 mm was prepared, and the cross section was coated with platinum to prepare an observation sample. Next, the film cross section was observed at an acceleration voltage of 1.0 kV using a field emission retardation electron microscope (S-4800) manufactured by Hitachi, Ltd., and the thickness of the resin layer A and the thickness of the layer B were observed from any part of the observation image. Was measured. The thicker layer of the two layers was the resin layer A, the thinner layer was the layer B, and the observation magnification was 10,000 times. Further, the same measurement was performed 20 times in total, and the average value was used as the thickness T (A) of the resin layer A and the thickness T (B) of the layer B.

(3) Melting point of resin layer A, glass transition temperature Weigh 5 mg of resin layer A determined by the procedure described in (2), and use a differential scanning calorimeter (EXSTAR DSC6220 manufactured by Seiko Instruments Inc.) in a nitrogen atmosphere. It was heated and cooled according to the following program.
<Program>
Step 1: Heat from 25 ° C. to 330 ° C. at 10 ° C./min and then keep at 330 ° C. for 5 minutes.
Step 2: After cooling from 330 ° C to 25 ° C at -10 ° C / min, keep at 25 ° C for 5 minutes.
Step 3: Heat from 25 ° C. to 330 ° C. at 10 ° C./min and then keep at 330 ° C. for 5 minutes.
In the temperature raising process of step 3, when the DSC chart is viewed from 330 ° C. toward the low temperature side, the maximum value of the temperature at which the slope of the DSC chart changes from the slope of the baseline is set to T_1, and the temperature is less than T_1. The minimum value of the temperature at which the slope of the DSC chart returned to the slope of the baseline was defined as T_2, and the value Tg obtained by the following formula was defined as the glass transition temperature of the resin layer A.
<Calculation formula>
Tg = (T_1 + T_2) / 2.

Further, the peak temperature of the endothermic curve obtained in step 3 was defined as the melting point of the resin layer A, and when a plurality of peak temperatures could be observed, the highest temperature was defined as the melting point of the resin layer A. However, no peak was observed in the endothermic curve obtained in step 3, and when the DSC chart was viewed from 330 ° C. toward the low temperature side in the temperature raising process in step 3, the DSC chart was in the region of 25 ° C. or higher. When the inclination did not change from the inclination of the baseline, both the melting point of the resin layer A and the glass transition temperature were set to 330 ° C. or higher. No peak was observed in the endothermic curve obtained in step 3, but when the glass transition temperature was less than 330 ° C., it was regarded as having no melting point. In the heating process of step 3, when the DSC chart was viewed from 330 ° C. toward the low temperature side, the slope of the DSC chart did not change from the slope of the baseline in the region of 25 ° C. or higher, but the melting point was 330 ° C. If it was less than, there was no glass transition temperature. When applicable, they are described as "-" in Tables 1 to 3, respectively.

(4) Atomic fractions of hydrogen atom H, carbon atom C, sulfur atom S, silicon atom Si, nitrogen atom N and oxygen atom O contained in resin layer A and layer B, and oxygen atom O and silicon of layer B. Atomic Si content The surface of the film on the resin layer A side was analyzed by the Rutherford backward scattering / hydrogen forward scattering analysis simultaneous measurement method (Pelletron 3SDH manufactured by National Electrostatics Corporation), and the hydrogen atom H, carbon atom C, and sulfur of the resin layer A were analyzed. Atomic yields Y (H), Y (C), Y (S), Y (Si), Y (N) and Y (O) of atom S, silicon atom Si, nitrogen atom N and oxygen atom O were obtained. .. From the obtained values, the values obtained based on the following equation are the atomic fractions of hydrogen atom H, carbon atom C, sulfur atom S, silicon atom Si, nitrogen atom N and oxygen atom O contained in the resin layer A. And said.
<Calculation formula>
Y (All) = Y (C) + Y (S) + Y (Si) + Y (N) + Y (O) + Y (H).
Atomic fraction of hydrogen atom H = Y (H) / Y (All)
Atomic fraction of carbon atom C = Y (C) / Y (All)
Atomic fraction of sulfur atom S = Y (S) / Y (All)
Atomic fraction of silicon atom Si = Y (Si) / Y (All)
Atomic fraction of nitrogen atom N = Y (N) / Y (All)
Atomic fraction of oxygen atom O = Y (O) / Y (All).

Layer B is also analyzed by the same procedure except that the surface to be analyzed by the Rutherford backward scattering / hydrogen forward scattering analysis simultaneous measurement method is the surface on the layer B side, and each value is calculated and contained in layer B. The atomic fractions of hydrogen atom H, carbon atom C, sulfur atom S, silicon atom Si, nitrogen atom N and oxygen atom O were used. In addition, the contents of oxygen atom O and silicon atom Si in layer B were calculated based on the following equations. The atomic fractions Y (C), Y (S), Y (Si), Y (N), Y (O), and Y (H) in the equation are all those of layer B.
<Calculation formula>
Oxygen atom O content (mass%) = 100 x 16.0 x Y (O) / (12.0 x Y (C) + 32.1 x Y (S) + 28.1 x Y (Si) + 14.0 x Y (N) + 16.0 × Y (O) +1.01 × Y (H))
Silicon atom Si content (mass%) = 100 × 28.1 × Y (Si) / (12.0 × Y (C) +32.1 × Y (S) +28.1 × Y (Si) + 14.0 × Y (N) +16.0 × Y (O) +1.01 × Y (H))
The measurement conditions are as follows.
Incident ions: ⁴ He ⁺⁺
Incident energy: 2300keV
Angle of incidence: 75deg
Scattering angle: 160deg
Recoil angle: 30deg
Sample current: 4nA
Beam diameter: 2mmφ
In-plane rotation: No irradiation amount: 0.5 μC x 20 points (5) XA, XB
Using each value obtained by the method described in (4), XB was calculated by the following formula (a) and XA was calculated by the following formula (b).
Equation (a) XB = (atomic fraction of carbon atom C in layer B + atomic fraction of nitrogen atom N in layer B + atomic fraction of sulfur atom S in layer B + atomic fraction of silicon atom Si in layer B ) / (Atomic fraction of hydrogen atom H in layer B + atomic fraction of oxygen atom O in layer B)
Formula (b) XA = (atomic fraction of carbon atom C in resin layer A + atomic fraction of nitrogen atom N in resin layer A + atomic fraction of sulfur atom S in resin layer A + silicon atom Si in resin layer A Atomic fraction) / (atomic fraction of hydrogen atom H in resin layer A + atomic fraction of oxygen atom O in resin layer A).

(6) Dynamic friction coefficient (μdaa, μdab, μdbb)
Using a slip tester manufactured by Toyo Seiki Co., Ltd., the dynamic friction coefficient was measured at a load of 200 g, 25 ° C., and 65% RH according to JIS K 7125 (1999). When one side of the film was an α-plane and the other side was a β-plane, the measurement was performed in two cases, one in which the α-planes were overlapped and the other in which the β-planes were overlapped with each other. The measurement was performed three times each, and the average value of the obtained values was calculated and used as the coefficient of dynamic friction when measured between the surfaces. Of the α and β planes, when the surface with the larger dynamic friction coefficient when measured by overlapping each surface is the a plane and the smaller surface is the b plane, the dynamic friction coefficient between the a planes is μdaa, The coefficient of dynamic friction between the b-sides was set to μdbb. Further, the measurement was performed three times in the case where the a-plane and the b-side were overlapped, and the average value of the obtained values was calculated and used as μdab. In each case, when the frictional force detected by the load cell during the measurement exceeded 5.9N, the measurement was interrupted and the measured value of the dynamic friction coefficient in that case was set to> 3.0. When the dynamic friction coefficients measured on the same surfaces are equal or> 3.0, the surface with the higher arithmetic mean roughness Sa measured by the method described later is defined as the b surface.

(7) Arithmetic mean roughness Sa, load area ratio Smr1, protruding peak height Spk, maximum valley depth Sv
Each parameter was measured and calculated according to ISO25178-2: 2012 and ISO25178-3: 2012. However, the measurement is performed using the scanning white interference microscope "VS1540" (manufactured by Hitachi High-Tech Science Corporation, the measurement conditions and device configuration will be described later), and the shooting screen is complemented (completely complemented) by the attached analysis software. After surface correction by polynomial quaternary approximation, the measurement was performed by processing with a median filter (3 × 3 pixels). The S-Filter Nesting Index of S-filter was set to 0.455. The measurement is performed on both sides of a 5 cm x 5 cm square cut film, the diagonal intersection is the first measurement point (starting point), and the position 1 cm away from each of the four corners from the starting point is set. A total of 5 measurement positions are determined as the 2nd to 5th measurement points, measurement is performed at each measurement position, Sa, Smr1, Spk, and Sv at each measurement position are obtained according to the above procedure, and the average value of each is calculated. It was adopted as Sa, Smr1, Spk, and Sv of the film. In particular, the values of Spk on the a-plane were set to Spk-a, and the values of Spk and Smr1 on the b-side were set to Spk-b and Smr1-b, respectively. From the obtained values of Spk-a and Spk-b, Spk-b / Spk-a was calculated. Sv / T (F) was calculated from the obtained Sv value of each surface and the above-mentioned T (F) value.
<Measurement conditions and device configuration>
Objective lens: 10x
Lens barrel: 1x
Zoom lens: 1x
Wavelength filter: 530nm white
Measurement mode: Wave
Measurement software: VS-Measure 10.0.4.0
Analysis software: VS-Viewer 10.0.3.0
Measurement area: 561.1 μm × 561.5 μm
Number of pixels: 1,024 x 1,024.

(8) SH defect rate, self-healing property A corona discharge treatment was performed on the surface of the layer B side in the atmosphere at a treatment strength of ^{25 W · min / m 2.} The film having no layer B was subjected to a corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2 on the b surface.} Next, commercially available aluminum was vapor-deposited on the corona discharge-treated surface with a Belger-type vacuum vapor deposition apparatus at an atmospheric pressure of 1.0 × 10 ^-3 Pa and a filament voltage of 2.6 kV to form a 50 nm vapor-deposited film to obtain a metal layer laminated film. .. The obtained metal layer laminated film was cut into a rectangular shape of 12 cm × 7.5 cm having a long side in the longitudinal direction to obtain a test piece.

A 10 cm square, 1 mm thick "Teflon" (registered trademark) sheet was placed on a 1 m x 2 m copper plate. On the "Teflon" (registered trademark) sheet, the short side of the test piece and one side of the "Teflon" (registered trademark) sheet are parallel, and the area 1 cm from the short side on one side of the test piece is ". A test piece was placed so that it could ride on the Teflon (registered trademark) seat. A 5 cm square plate-shaped conductive rubber electrode was placed on the "Teflon" (registered trademark) sheet so that the part of the test piece on the "Teflon" (registered trademark) sheet was ^{sandwiched by about 2 cm 2.} .. Further, a 3 cmφ cylindrical electrode was placed on the rubber electrode so that the center of gravity was on the region where the rubber electrode, the test piece, and the “Teflon” (registered trademark) sheet overlapped. A DC power supply is connected to the cylindrical electrode and the copper plate via electric wires, and a voltage of 100 VDC is applied as the initial voltage. After 15 seconds have passed at that voltage, the voltage is gradually applied to the initial voltage + 800 VDC in steps of 100 VDC / 30 seconds. A so-called step-up test was carried out in which the voltage was repeatedly raised, and a plurality of dielectric breakdown marks were generated on the metal layer laminated film.

Visually observe the generated dielectric breakdown marks, and determine the number of each with the dielectric breakdown marks where two or more dielectric breakdown marks overlap as one SH defective part and the other insulation breakdown marks as one normal part. The SH defect rate was calculated by the formula. The same measurement was performed twice, and the average value was adopted as the SH defect rate of the film. When dielectric breakdown did not occur, the same measurement was performed with the initial voltage set to 900 VDC. When dielectric breakdown did not occur even at the initial voltage of 10,000 VDC, the SH defect rate was set to 0%.
<Calculation formula>
SH defect rate (%) = 100 x (number of SH defective parts) / (number of normal parts + number of SH defective parts)
Based on the SH defect rate of the film, the self-healing property was evaluated as follows.
S: The SH defect rate is 16% or less.
A: The SH defect rate is larger than 16% and 22% or less.
B: The SH defect rate is larger than 22% and 30% or less.
C: SH defect rate is greater than 30%.

(9) Evaluation of Workability The surface on the layer B side was subjected to corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2.} The film having no layer B was subjected to a corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2 on the b surface.} Next, commercially available aluminum was vapor-deposited on the corona discharge-treated surface with a Belger-type vacuum vapor deposition apparatus at an atmospheric pressure of 1.0 × 10 ^-3 Pa and a filament voltage of 2.6 kV to form a 50 nm vapor-deposited film to obtain a metal layer laminated film. .. The obtained metal layer laminated film was cut into a rectangular shape of 12 cm × 7.5 cm having a long side in the longitudinal direction to obtain a test piece. Using a slip tester manufactured by Toyo Seiki Co., Ltd., the metal vapor deposition surface and the metal vapor deposition of the metal layer laminated film obtained at a load of 200 g, 25 ° C., and 65% RH according to JIS K 7125 (1999). The coefficient of kinetic friction between the surface and the surface not covered was measured three times, and the average value of the obtained values was defined as the coefficient of kinetic friction of the metal laminated film μM. When the frictional force detected by the load cell during the measurement exceeded 5.9N, the measurement was interrupted and the measured value of μM in that case was set to> 3.0. Based on the obtained μM, the processability of the film was judged according to the following criteria.
S: μM is 0.60 or less.
A: μM is larger than 0.60 and 0.90 or less.
B: μM is larger than 0.90 and 1.5 or less.
C: μM is greater than 1.5.

(10) Dissipation Factor The dielectric loss tangent was measured according to JIS C2138-2007. First, the film was cut into a square shape of 6 cm × 6 cm, and the surface on the layer B side was subjected to corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2.} The film having no layer B was subjected to a corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2 on the b surface.} Next, commercially available aluminum was vapor-deposited on the corona discharge-treated surface with a bellger-type vacuum vapor deposition apparatus at an atmospheric pressure of 1.0 × 10 ^-3 Pa and a filament voltage of 2.6 kV to form a circular thin film electrode having a diameter of 5.0 cm and a thickness of 50 nm. .. ^{Subsequently, the pressure pressure was 1.0 × 10 -3} Pa, so that the center and the center position of the electrodes formed on the corona discharge-treated surface of the film were aligned with the surface of the film that had not been subjected to the corona discharge treatment. A commercially available aluminum was vapor-deposited at a filament voltage of 2.6 kV to form a circular thin film electrode having a diameter of 5.6 cm and a thickness of 50 nm to obtain a test piece. The obtained test piece was measured for dielectric loss tangent at n = 5 at a contact method, 23 ° C., relative humidity 50%, and frequency 10 kHz with an E4980A precision LCR meter (manufactured by Keysight Technologies), and the average value of the obtained values was measured. Was defined as the dielectric loss tangent of the film.

(11) Evaluation of film dielectric breakdown voltage at 150 ° C. After heating the film for 1 minute in an oven kept at 150 ° C., JIS C2330 (2001) 7.4.11.2 B method (plate electrode) Measured according to the method). However, for the lower electrode, "Conductive rubber E-100 <65>" manufactured by Togawa Rubber Co., Ltd., which has the same dimensions, is placed on the metal plate described in Method B of JIS C2330 (2001) 7.4.11.2. I used the one. The dielectric breakdown voltage test (measurement above) was performed 30 times, and the obtained value was divided by the thickness of the film (measured in (1) above) and converted to (V / μm) for a total of 30 measurements. Among the values (calculated values), the average value of 20 points excluding 5 points in descending order from the maximum value and 5 points in ascending order from the minimum value was obtained, and this was used as the film dielectric breakdown voltage at 150 ° C. From the obtained film dielectric breakdown voltage at 150 ° C., the film dielectric breakdown voltage at 150 ° C. was evaluated as follows.
S: The film dielectric breakdown voltage at 150 ° C. was 270 V / μm or more.
A: The film dielectric breakdown voltage at 150 ° C. was 240 V / μm or more and less than 270 V / μm.
B: The film dielectric breakdown voltage at 150 ° C. was 210 V / μm or more and less than 240 V / μm.
C: The film dielectric breakdown voltage at 150 ° C. was 100 V / μm or more and less than 210 V / μm.
D: The film dielectric breakdown voltage at 150 ° C. was less than 100 V / μm, or the film shrinkage was too large to evaluate.

(12) Evaluation of film capacitor characteristics (reliability at 150 ° C)
The surface of the film on the layer B side was subjected to a corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2.} The film having no layer B was subjected to a corona discharge treatment in the atmosphere at a treatment strength of ^{25 W · min / m 2 on the b surface.} Next, a so-called T-shaped margin (longitudinal pitch with masking oil) was provided on the corona discharge-treated surface by using a vacuum vapor deposition machine manufactured by ULVAC Co., Ltd. to provide a margin portion in the direction perpendicular to the longitudinal direction with a film resistance of 10 Ω / sq. A vapor deposition pattern having a period) of 17 mm and a fuse width of 0.5 mm) was used for vapor deposition, and after slitting, a thin-film deposition reel having a film width of 50 mm (end margin width of 2 mm) was obtained. Next, using this reel, a film capacitor element was wound by a device winding machine (KAW-4NHB) manufactured by Minato Seisakusho Co., Ltd., subjected to metallikon, and then heat-treated at a temperature of 130 ° C. for 8 hours under reduced pressure. , I attached the lead wire and finished it as a film capacitor element. Using the 10 capacitor elements thus obtained, a voltage of 250 VDC is applied to the capacitor element at a high temperature of 150 ° C., and after 10 minutes have passed at the voltage, the applied voltage is gradually increased at 50 VDC / 1 minute in steps. A so-called step-up test was conducted in which the above steps were repeated. After increasing the voltage until the capacitance decreased to 12% or less of the initial value, the capacitor element was disassembled and the state of destruction was examined, and the characteristics of the film capacitor were evaluated as follows.
S: There was no change in the shape of the film capacitor element, and no penetrating fracture was observed.
A: There was no change in the shape of the film capacitor element, and penetrating fracture within the 5th layer of the film was observed.
B: There was no change in the shape of the film capacitor element, and penetrating fracture penetrating the 6th to 7th layers of the film was observed.
C: A change was observed in the shape of the film capacitor element. Alternatively, penetrating fracture of 8 to 14 layers of the film was observed.
D: The shape of the film capacitor element changed significantly and was destroyed, or the workability of the film was poor, and the film capacitor element could not be manufactured.
-: The characteristics of the film capacitor were not evaluated.
S can be used without any problem, A can be used depending on the conditions, B is inferior in practical performance but can be used, and C is inferior in practical performance depending on the conditions but can be used. D is difficult to use as a film for a capacitor.

[Resin, film, coating liquid]
Polyphenylene sulfide resin granules 1 (PPS granules 1):
In a 1 liter autoclave with a process stirrer, 1.00 mol of 47 mass% sodium hydroxide, 1.02 mol of 96 mass% sodium hydroxide, 1.56 mol of N-methyl-2-pyrrolidone (NMP), 0 sodium acetate. .46 mol and 140 g of ion-exchanged water were charged, and gradually heated to 225 ° C. over about 3 hours while stirring at 250 rpm and passing through nitrogen at normal pressure, and after distilling out 212 g of water and 4 g of NMP, the reaction was carried out. The container was cooled to 160 ° C. Next, 1.00 mol of p-dichlorobenzene (p-DCB) and 1.32 mol of NMP were added, and the reaction vessel was sealed under nitrogen gas. Then, while stirring at 240 rpm, the temperature was raised from 200 ° C. to 235 ° C. at a rate of 0.6 ° C./min, and after reaching 235 ° C., the reaction was continued at 235 ° C. for 95 minutes. Then, the temperature was raised to 270 ° C. at a rate of 0.8 ° C./min and held for 100 minutes. At this time, after reaching 270 ° C., 1 mol of water was injected into the system over 15 minutes. After holding at 270 ° C. for 100 minutes, the mixture was cooled to 200 ° C. at a rate of 1.0 ° C./min, and then cooled to near room temperature by applying cooling water at room temperature to an autoclave. Subsequently, the contents were taken out, diluted with 0.4 liters of NMP, stirred at 85 ° C. for 30 minutes, and then the solvent and solids were filtered off by sieving (80 mesh). Further, 0.5 liter of NMP was added to the obtained solid, and the mixture was stirred at 85 ° C. for 30 minutes, and the solid was filtered off. Then, the obtained solid substance was washed with 0.9 liter of warm water three times and filtered off. 1 liter of warm water was added to the particles (solid matter) thus obtained, washed twice, and filtered to obtain polymer particles. This was dried with hot air at 80 ° C. and then dried under reduced pressure at 120 ° C. to obtain polyphenylene sulfide (PPS) resin granules (PPS granules 1) having a melting point of 280 ° C. and a weight average molecular weight of 70,000.

PPS raw material 1 for film (PPS1):
The PPS granules 1 were put into a uniaxial rotary twin-screw kneading extruder with a vent heated to 320 ° C. (manufactured by Japan Steel Works, screw diameter 30 mm, screw length / screw diameter = 45.5), and the residence time was 90. It was melt-extruded at a screw rotation speed of 150 rpm for seconds, discharged in a strand shape, and cooled with water having a temperature of 25 ° C. Immediately after that, chips were produced by cutting to obtain PPS raw material 1 for film (PPS1).

PPS raw material for film (PPS2):
100 parts by mass of PPS granules 1, 0.05 parts by mass of calcium carbonate particles 1 (“NITOREX” # 30PS manufactured by Nitto Powder Industry Co., Ltd.) with an average particle size of 0.7 μm, and 0.2 parts by mass of calcium stearate. The mixed powder obtained by mixing with and was pelletized to prepare resin pellets containing PPS as a main component. The obtained resin pellets were put into a uniaxial rotary twin-screw kneading extruder with a vent heated to 320 ° C. (manufactured by Japan Steel Works, screw diameter 30 mm, screw length / screw diameter = 45.5), and the residence time. It was melt-extruded at a screw rotation speed of 150 rpm for 90 seconds, discharged in a strand shape, and cooled with water having a temperature of 25 ° C. Immediately after that, chips were produced by cutting to obtain PPS raw material 2 for film (PPS2).

PPS film 1:
As a raw material, PPS1 was vacuum dried at 180 ° C. for 3 hours. Then, it was supplied to an extruder, melted at a temperature of 320 ° C. under a nitrogen atmosphere, and introduced into a T-die base. Next, it is extruded into a sheet from the inside of the T-die base to form a molten single-layer sheet, which is discharged onto a cast drum having a rotation speed of 4.0 m / min maintained at a surface temperature of 25 ° C. and adhered by an electrostatic application method. The film was cast by cooling and solidifying to obtain an unstretched film. The obtained unstretched film was stretched at a stretching temperature of 103 ° C. in the longitudinal direction of the film at a magnification of 3.1 times using a longitudinal stretching machine composed of a plurality of heated roll groups. .. Then, both ends of the obtained uniaxially stretched film in the width direction were supported by clips and guided to a tenter, and stretched at a stretching temperature of 100 ° C. at a magnification of 3.3 times in the width direction. Subsequently, the heat treatment was performed at 280 ° C., followed by a 2% relaxation treatment, and the mixture was cooled to room temperature. Next, the film surface (cast drum contact surface side) was ^{subjected to corona discharge treatment in the atmosphere at a processing strength of 25 W · min / m 2} , and then the film edge was removed to obtain a biaxially stretched PPS film having a thickness of 4.5 μm. rice field.

PPS film 2:
A biaxially stretched PPS film having a thickness of 4.6 μm was obtained in the same manner as the PPS film 1 except that PPS2 was used instead of PPS1 as a raw material.

Coating liquid 1:
Contains 70 g of acrylate (I) (trade name "Viscoat"# 300, a condensate of pentaerythritol and acrylic acid, 45% by mass of pentaerythritol tetraacrylate, and 35% by mass of pentaerythritol triacrylate, Osaka Organic Chemical Industries, Ltd. (Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 50 g of cellulose acetate (i) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., vinegarization degree 54%), 880 g of 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 200 mg. A coating solution mixed with Omnirad 184 (1-hydroxycyclohexylphenylketone manufactured by IGM Resins VV).

Coating liquid 2:
70 g of acrylate (II) (trade name "EBECRYL" (registered trademark) 150, manufactured by Daicel Ornex Co., Ltd., ethylene oxide-modified bisphenol A diacrylate), 30 g of cellulose acetate (i), and 900 g of 2-butanone (Fuji). A coating solution in which 200 mg of Omnirad 184 (manufactured by IGM Resins VV, manufactured by 1-hydroxycyclohexylphenylketone) is mixed with Film Wako Pure Chemical Industries, Ltd.

Coating liquid 3:
80 g of acrylate (I), 11 g of epoxy resin (trade name "EPICLON" 850, active group equivalent 189 eq / g, manufactured by DIC Corporation), and 9.0 g of active ester (trade name "HPC-8000-65T"). , Active group equivalent 223 eq / g, manufactured by DIC Corporation), 900 g of 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 200 mg of Omnirad 184 (manufactured by IGM Resins VV, manufactured by 1-hydroxycyclohexylphenyl). A coating solution in which 10 mg of 4-dimethylaminopyridine (manufactured by Tokyo Kasei Kogyo Co., Ltd.) is mixed.

Coating liquid 4:
99.5 g of acrylate (II), 500 mg of acrylic resin (trade name "MP-1451", non-crosslinked acrylic particles, manufactured by Soken Chemical Industries, Ltd., average particle diameter of 150 nm), and 900 g of 2-butanone (Wako Pure Chemical Industries, Ltd.) A coating solution prepared by mixing 200 mg of Omnirad 184 (manufactured by IGM Resins VV, manufactured by 1-hydroxycyclohexylphenyl ketone) with Kojunyaku Co., Ltd.

Coating liquid 5:
54 g of epoxy resin (trade name "EPICLON" (registered trademark) 850, active group equivalent 189 eq / g, manufactured by DIC Corporation) and 45.5 g of active ester (trade name "HPC-8000-65T", active group equivalent) 223eq / g, manufactured by DIC Corporation, 500 mg of acrylic resin (trade name "MP-1451", non-crosslinked acrylic particles, manufactured by Soken Kagaku Co., Ltd., average particle size 150 nm), and 900 g of 2-butanone (Fujifilm). A coating solution in which 10 mg of 4-dimethylaminopyridine (manufactured by Tokyo Kasei Kogyo Co., Ltd.) is mixed with Wako Pure Chemical Industries, Ltd.

Coating liquid 6:
65 g of acrylate (I), 35 g of terpene phenol resin (trade name "TH130", manufactured by Yasuhara Chemical Industries, Ltd.), 900 g of 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 200 mg of Omnirad 184 (IGM Resins B). A coating solution mixed with 1-hydroxycyclohexylphenyl ketone (manufactured by V. V.).

Coating liquid 7:
500 mg of acrylic resin (trade name "MP-1451", non-crosslinked acrylic particles, manufactured by Soken Chemical Industries, Ltd., average particle size 150 nm), 99.5 g of cellulose acetate (i), and 900 g of 2-butanone (Fuji Film). A coating solution mixed with Wako Pure Chemical Industries, Ltd.).

Coating liquid 8:
99.9 g of nitrile butadiene rubber (trade name "Nipol" (registered trademark) DN003, manufactured by Nippon Zeon Corporation, Mooney viscosity 77.5) and 100 mg of calcium carbonate particles 2 (trade name "CALUCEO" (registered trademark) P015S0) , Particle size 150 nm) and 900 g of 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

Coating liquid 9:
54 g of epoxy resin (trade name "EPICLON" (registered trademark) 850, active group equivalent 189 eq / g, manufactured by DIC Corporation) and 45.5 g of active ester (trade name "HPC-8000-65T", active group equivalent) 223eq / g, manufactured by DIC Corporation, silica particles (y) (average particle size 0.1 μm, "sea hoster" (registered trademark) KE-P10, manufactured by Nippon Catalyst Co., Ltd.), and 900 g of 2-butanone (Fuji). A coating solution in which film Wako Pure Chemical Industries, Ltd.) and 10 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) are mixed.

Coating liquid 10:
A coating in which 100 g of acrylate (I), 900 g of 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 200 mg of Omnirad 184 (manufactured by IGM Resins BV, 1-hydroxycyclohexylphenyl ketone) are mixed. liquid.

Coating liquid 11:
99.5 g of polyetherimide (trade name "ULTEM" (registered trademark) Resin 1010, manufactured by SABIC, glass transition temperature 217 ° C), 500 mg of calcium carbonate particles 2, and 900 g of N-methylpyrrolidone (Fujifilm sum). A coating liquid mixed with (manufactured by Kojunyaku Co., Ltd.).

(Example 1)
15 g of polyetherimide resin (trade name "ULTEM" (registered trademark) Resin 1010, manufactured by SABIC, glass transition temperature 217 ° C) is dissolved in 85 g of N-methyl-2-pyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). To prepare an NMP solution of polyetherimide. This is coated on a commercially available polyimide film (thickness 140 μm) using a # 20 metabar and dried in an oven at 150 ° C. for 15 minutes to form a polyetherimide resin layer (resin layer A) on the polyimide film. I let you. Next, 2.1 g of terpene phenol resin (trade name "TH130", manufactured by Yasuhara Chemical Industries, Ltd.) and silica particles (x) (average particle diameter 0.7 μm, "Sunseal" (registered trademark) SS-07, Tokuyama Corporation 25 mg and 12 g of 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed to prepare a coating solution in which a terpene phenol resin was dissolved. This is coated on a polyetherimide resin layer on a polyimide film using a # 4 metabar and dried in an oven at 100 ° C. for 1 minute to form a coat layer (layer B) on the polyetherimide resin layer. I let you. The laminate of the polyetherimide resin layer and the coat layer was peeled off from the polyimide film to obtain a film for a film capacitor. The evaluation results are shown in Table 1.

(Example 2)
A film for a film capacitor was obtained in the same manner as in Example 1 except that the mixed amounts of the terpene phenol resin, the silica particles (x) and 2-butanone were 0.70 g, 8 mg and 14.2 g, respectively. The evaluation results are shown in Table 1.

(Example 3)
After applying the coating liquid 1 uniformly on the corona-treated surface of the PPS film 1 (resin layer A) using a bar coater so that the film thickness of the cured layer B is 0.10 μm. It was dried in a drying oven at 90 ° C. so that the drying time was 1 minute. Subsequently, it was introduced into a UV irradiation device, ^{and the coating film was cured under the conditions of an illuminance of 50 mW / cm 2} , an irradiation amount of 0.1 J / cm ² , and an oxygen concentration of 100 ppm to form a layer B, and then the resin layer A and the layer B were formed. Was wound up to obtain a film for a film capacitor. The evaluation results are shown in Table 1.

(Example 4)
A film for a film capacitor was obtained in the same manner as in Example 3 except that the coating liquid 2 was used instead of the coating liquid 1. The evaluation results are shown in Table 1.

(Example 5)
A film for a film capacitor was obtained in the same manner as in Example 3 except that the coating liquid 3 was used instead of the coating liquid 1 and the drying temperature in the drying furnace was set to 120 ° C. The evaluation results are shown in Table 1.

(Example 6)
A film for a film capacitor was obtained in the same manner as in Example 3 except that the coating liquid 4 was used instead of the coating liquid 1. The evaluation results are shown in Table 1.

(Example 7)
A film for a film capacitor was obtained in the same manner as in Example 3 except that the coating liquid 5 was used instead of the coating liquid 1. The evaluation results are shown in Table 1.

(Example 8)
150 g of the polyetherimide resin was dissolved in 850 g of N-methyl-2-pyrrolidone to prepare an NMP solution of the polyetherimide. This is uniformly coated on a commercially available polyimide film (thickness 140 μm) using a bar coater so that the thickness of the polyetherimide layer after drying becomes 3 μm, and introduced into a drying furnace at 150 ° C. for drying time. It was dried for 5 minutes to form a polyetherimide resin layer (resin layer A) on the polyimide film. The surface of the obtained laminate on the resin layer A side is uniformly coated with the coating liquid 6 so that the thickness of the cured layer B is 0.1 μm using a bar coater, and then in a drying oven at 90 ° C. It was dried so that the drying time was 1 minute. Subsequently, it was introduced into a UV irradiation device, ^{and the coating film was cured under the conditions of an illuminance of 50 mW / cm 2} , an irradiation amount of 0.1 J / cm ² , and an oxygen concentration of 100 ppm to form a layer B. Subsequently, the laminate of the resin layer A and the layer B was peeled off from the polyimide film and wound up to obtain a film for a film capacitor. The evaluation results are shown in Table 2.

(Example 9)
A polyetherimide resin layer (resin layer A) is formed on a commercially available polyimide film in the same manner as in Example 8, and the thickness of the layer B after drying using a bar coater on the resin layer A becomes 0.10 μm. The coating liquid 7 was applied in this manner and dried in a drying oven at 90 ° C. so that the drying time was 1 minute to form the layer B. Then, the laminate of the resin layer A and the layer B was peeled off from the polyimide film and wound up to obtain a film for a film capacitor. The evaluation results are shown in Table 2.

(Example 10)
A film for a film capacitor was obtained in the same manner as in Example 3 except that the coating liquid 9 was used instead of the coating liquid 1. The evaluation results are shown in Table 2.

(Example 11)
A film for a film capacitor was obtained in the same manner as in Example 3 except that the PPS film 2 was used instead of the PPS film 1 and the coating liquid 10 was used instead of the coating liquid 1. The evaluation results are shown in Table 2.

(Example 12)
A film for a film capacitor was prepared in the same manner as in Example 3 except that the coating liquid 11 was used instead of the coating liquid 1, the temperature of the drying furnace was changed from 90 ° C. to 150 ° C., and the drying time was set to 1 minute to 5 minutes. Obtained. The evaluation results are shown in Table 2.

(Example 13)
100 g of cellulose acetate (i) was dissolved in 900 g of methyl ethyl ketone to prepare a methyl ethyl ketone solution of cellulose acetate. This is coated on a commercially available polyimide film (thickness 140 μm) using a bar coater so that the thickness of the cellulose acetate layer after drying is 3.2 μm, and introduced into a drying furnace at 100 ° C. for drying time. It was dried for 2 minutes to form a cellulose acetate resin layer (resin layer A) on the polyimide film. Subsequently, a coating liquid 7 was applied to the surface of the obtained laminate on the resin layer A side using a bar coater so that the thickness of the cured layer B was 0.10 μm, and the mixture was placed in a drying oven at 100 ° C. It was introduced and dried so that the drying time was 1 minute, and a layer B was formed on the resin layer A. The laminate of the resin layer A and the layer B was peeled off from the polyimide film and wound up to obtain a film for a film capacitor. The evaluation results are shown in Table 2.

(Example 14)
150 g of polyetherimide resin was dissolved in 850 g of N-methyl-2-pyrrolidone to prepare an NMP solution of polyetherimide. This is uniformly coated on a commercially available polyimide film (thickness 140 μm) using a bar coater so that the thickness of the polyetherimide layer after drying becomes 3 μm, and introduced into a drying furnace at 150 ° C. for drying time. It was dried for 5 minutes to form a polyetherimide resin layer (resin layer A) on the polyimide film. A silicone composition (silicone X-40-2655A manufactured by Shin-Etsu Chemical Co., Ltd.) was vapor-deposited on the surface of the obtained laminate on the resin layer A side by a vacuum vapor deposition method so as to have a thickness of 0.1 μm. Subsequently, while supplying a small amount of O2 gas to the coat layer surface, a glow discharge is generated using a pulse DC power supply of 250 kHz and 5 kW to perform a glow discharge treatment (processing power density E = 27.8 W · min / m ² ). Layer B was formed. The obtained laminate was wound to obtain a film for a film capacitor. The evaluation results are shown in Table 2.

(Comparative Example 1)
A film for a film capacitor having only the A layer was obtained in the same manner as in Example 1 except that the step of forming the layer B after forming the resin layer A was omitted. The evaluation results are shown in Table 3.

(Comparative Example 2)
The coating liquid 8 is applied to the corona-treated surface of the PPS film 1 (resin layer A) with a bar coater so that the thickness of the layer B after curing is 0.50 μm, and the coating solution 8 is applied in an oven at 90 ° C. for 1 minute. It was dried to form layer B to obtain a film for a film capacitor. The evaluation results are shown in Table 3.

(Comparative Example 3)
The PPS film 1 was evaluated as a film for a film capacitor. The evaluation results are shown in Table 3.

(Comparative Example 4)
The PPS film 2 was evaluated as a film for a film capacitor. The evaluation results are shown in Table 3.

(Comparative Example 5)
A polyetherimide resin [Product name: ULTEM1010-1000-NB (hereinafter abbreviated as "1010-1000") manufactured by SABIC Innovative Plastics Co., Ltd.] was prepared as a molding material for the resin layer A, and the molding material was heated to 150 ° C. for dehumidification. Leave it in a hot air dryer [Matsui Seisakusho Co., Ltd. product name: Multijet MJ3] for 12 hours to dry it, and after confirming that the water content of this molding material is 300 ppm or less, put a T-die with a width of 900 mm on the molding material. It is set in a uniaxial extruder with a diameter of 40 mm and melt-kneaded, and the melt-kneaded molding material is continuously extruded from the T-die of the uniaxial extruder to form a strip of polyetherimide resin film. Extrusion molding was performed to prepare a polyetherimide resin layer having a length of 1000 m and a width of 65 cm. The cylinder temperature of the single-screw extruder was adjusted to 360 to 380 ° C, the temperature of the T-die was adjusted to 385 ° C, and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 380 ° C. Further, when the molding material was charged into the single-screw extrusion molding machine, 18 L / min of nitrogen gas, which is an inert gas, was supplied. The formed polyetherimide resin layer is subjected to a pair of pressure-bonding rolls provided with silicone rubber having an arithmetic mean roughness (Ra) of 0.44 to 0.47 μm, and an arithmetic mean roughness (Ra) of 1.28 μm on the peripheral surface. The metal roll, which is a cooling roll at 205 ° C. having a convex pattern, and a 6-inch take-up pipe located downstream of the metal roll were sequentially wound around the metal roll, and were sandwiched between each crimping roll and the metal roll for cooling. By sandwiching the polyetherimide resin layer between the pressure-bonding roll and the metal roll, a plurality of fine uneven portions were formed on the front and back surfaces of the polyetherimide resin layer. Using the obtained polyetherimide resin layer having fine irregularities on the surface as the resin layer A, diparaxylylene is vaporized under the conditions of 180 ° C. and 10 Pa, and is thermally decomposed and thermally decomposed under the conditions of 680 ° C. and 10 Pa. The diradical paraxylylene monomer thus obtained was polymerized on the metal roll surface side of the resin layer A under the conditions of 35 ° C. and 10 Pa to form a layer B made of a polyparaxylylene resin. The obtained laminate was wound to obtain a film for a film capacitor. The evaluation results are shown in Table 3.

(Comparative Example 6)
Single-screw melt extrusion of a linear polypropylene resin polymerized with a Cheegler-Natta catalyst, having a mesopentad fraction of 0.98, a melting point of 167 ° C, and a melt flow rate (MFR) of 2.6 g / 10 min. It is supplied to the machine, melt-extruded at 240 ° C., foreign matter is removed with an 80 μm-cut sintered filter, the molten polymer is discharged from a T-die, and the molten sheet is statically placed on a casting drum held at 95 ° C. An unstretched sheet was obtained by bringing them into close contact with each other by applying electricity and cooling and solidifying. Next, the sheet was gradually preheated to 145 ° C. in a plurality of roll groups, subsequently kept at a temperature of 145 ° C., passed between rolls provided with a peripheral speed difference, and stretched 5.0 times in the longitudinal direction. Subsequently, the film was led to a tenter, stretched 8 times in the width direction at a temperature of 165 ° C., and then heat-treated at 130 ° C. while giving 8% relaxation in the width direction as the first stage heat treatment and relaxation treatment, and further 2 As the heat treatment of the step, the heat treatment was performed at 140 ° C. while being gripped in the width direction with a clip. Then, it was guided to the outside of the tenter through a cooling step at 100 ° C., the clip at the end of the film was released, and a film having a film thickness of 3.0 μm was wound to obtain a film for a film capacitor. The evaluation results are shown in Table 3.

In Example 1, Example 2, and Comparative Example 1, a film was produced from a single sheet, and a film having a sufficient length for processing the capacitor element could not be obtained. Therefore, the processing of the capacitor element and the film No evaluation of capacitor characteristics was performed.

The film for a film capacitor of the present invention can be applied to various applications such as packaging applications, tape applications, cable wrapping and electrical applications such as capacitors, and especially for high voltage applications that require withstand voltage and reliability at high temperatures. Can be used for capacitor applications.

Claims (15)

A resin layer A having a melting point of 180 ° C. or higher and / or a glass transition temperature of 130 ° C. or higher, and at least one outermost layer of the film have a layer B thinner than the resin layer A, and the oxygen atom content of the layer B is high. A film for a film capacitor, which is 1.0% by mass or more. The film for a film capacitor according to claim 1, wherein the dielectric loss tangent is 2.0% or less. The film for a film capacitor according to claim 1 or 2, wherein the content of silicon atom Si in the layer B is 27% by mass or less. The film for a film capacitor according to any one of claims 1 to 3, wherein the layer B satisfies the following condition (i).
Condition (i): Calculated based on the following equation (a) from the atomic fractions of hydrogen atom H, carbon atom C, sulfur atom S, silicon atom Si, nitrogen atom N and oxygen atom O contained in the layer B. The value XB is 0.90 or less.
Equation (a) XB = (atomic fraction of carbon atom C in layer B + atomic fraction of nitrogen atom N in layer B + atomic fraction of sulfur atom S in layer B + silicon atom Si in layer B (Atomic fraction of) / (Atomic fraction of hydrogen atom H in the layer B + Atomic fraction of oxygen atom O in the layer B) When the dynamic friction coefficient is measured between the same surfaces of the two outermost layer surfaces, the surface with the larger dynamic friction coefficient is defined as the a surface, the surface with the smaller dynamic friction coefficient is defined as the b surface, and the dynamic friction coefficient between the a surfaces is μdaa. The film for a film capacitor according to any one of claims 1 to 4, wherein μdaa> μdab and μdab ≦ 1.2 are satisfied when the coefficient of kinetic friction between the a-side and the b-side is μdab. The film for a film capacitor according to any one of claims 1 to 5, wherein at least one outermost layer surface satisfies the load area ratio Smr1 ≥ 12% that separates the protruding peak portion and the core portion. The ratio of the protruding peak height Spk-a of the a-plane to the protruding peak height Spk-b of the b-plane satisfies Spk-b / Spk-a ≧ 2.0, and the protruding peak of the b-plane The film for a film capacitor according to any one of claims 1 to 6, which satisfies the load area ratio Smr1-b ≥ 12% that separates the portion and the core portion. The film capacitor according to any one of claims 1 to 7, wherein when the film thickness is T (F), the maximum valley depth Sv of both outermost layer surfaces satisfies Sv / T (F) <0.30. Film for. The film for a film capacitor according to any one of claims 1 to 8, wherein the layer B contains two or more components that are incompatible with each other. Any of claims 1 to 9, wherein the resin layer A contains at least one resin among a polyphenylene sulfide resin, a polyetherimide resin, a polyphenylsulfone resin, and a polyethersulfone resin in an amount of 50% by mass or more and 100% by mass or less. The film for film capacitors described in. The film for a film capacitor according to any one of claims 1 to 10, wherein the layer B contains at least one resin of an acrylic resin, an epoxy resin, a cellulose derivative, and a polyester resin in an amount of 50% by mass or more and 100% by mass or less. A metal layer laminated film for a film capacitor having a metal layer on the surface of at least one outermost layer of the film for a film capacitor according to any one of claims 1 to 11. The metal layer laminated film for a film capacitor according to claim 12, which has the resin layer A, the layer B, and the metal layer in this order. The layer B is provided only on one surface of the resin layer A, the metal layer is provided on the layer B side, and of the two outermost layer surfaces, the one having the larger dynamic friction coefficient measured between the same surfaces. The metal layer laminated film for a film capacitor according to claim 13, wherein when the surface is a-side and the smaller surface is b-side, the b-side is on the layer B side when viewed from the resin layer A. A film capacitor using the metal layer laminated film for a film capacitor according to any one of claims 12 to 14.