JP2001023858A - Multilayer film for capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent break of a capacitor and to improve its performance such as its life by providing a modified copolymer polyester layer containing particles on at least one side of a polyethylene naphthalate film. SOLUTION: A polyethylene naphthalate film is formed by fusing and extruding a sheet through an extruding collet by an extruding method, drawing and orienting it. Polyethylene naphthalate is a polymer whose component is ethylene-2 and 6-naphthalate. Polyethylene naphthalate is formed by condensing naphthalene-2,6-dicarbon acid under existence of a catalyst. The modified copolymer polyester layer contains inorganic particles such as Si dioxide, Al oxide, Ti oxide and the like or organic particles such as mono-dispersible crosslinking polymer particles, heat-resistant polymer fine powder or the like. One side of the polyethylene naphthalate film is coated with the composition and is dried to laminate a modified copolymer polyester layer containing particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laminated film for a capacitor, and more particularly, to a laminated film for a high-voltage capacitor.

[0002]

2. Description of the Related Art Hitherto, a capacitor film in which a thermoplastic resin layer is provided on a polyester film and a wound type plastic film capacitor using the same have been known (for example, JP-A-61-99321). This publication discloses a technique of alternately laminating and winding two dielectric films and two metallized films each coated with a thermoplastic resin having a Shore hardness of D70 or less, and then performing a heat treatment. ing. This teaches that the deposited electrode and the dielectric film are brought into close contact with each other to prevent the destruction of the capacitor, thereby prolonging the life of this type of capacitor and improving the reliability.

[0003] However, wrinkles may occur at the time of lamination and winding with a metallized film using a dielectric film coated with a thermoplastic resin having a Shore hardness of D70 or less described in the above publication. When wrinkles occur, in the heat treatment process, the adhesion between the dielectric film coated with the thermoplastic resin and the metallized film may not be sufficient due to the presence of air due to the wrinkles. There is a need for further improvements in performance such as prevention of destruction and life.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has as its object to prevent wrinkles from being generated at the time of lamination and winding with a metallized film, and to provide a dielectric material. An object of the present invention is to provide a film and a metallized film with sufficient adhesion to prevent the capacitor from being destroyed and to improve the performance such as life.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above problems, and as a result, have found that a laminated film having a specific structure can easily solve the above problems. Was completed. That is, the gist of the present invention resides in a laminated film for a capacitor, which has a modified copolymerized polyester layer containing particles on at least one surface of polyethylene naphthalate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, the polyethylene naphthalate film is a film obtained by stretching and orienting a sheet melt-extruded from an extrusion die according to a so-called extrusion method. The term "polyethylene naphthalate" as used in the present invention refers to a polymer whose constituent units are substantially composed of ethylene-2,6-naphthalate units, but a small amount, for example, 10 mol% or less, preferably 5 mol% or less. And an ethylene-2,6-naphthalate polymer modified by the third component.

Polyethylene naphthalate is generally naphthalene-2,6-dicarboxylic acid or a functional derivative thereof,
For example, it is produced by condensation of dimethyl naphthalene-2,6-dicarboxylate and ethylene glycol under appropriate reaction conditions in the presence of a catalyst. in this case,
As the third component, for example, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,
Dicarboxylic acids such as 7-dicarboxylic acid or lower alkyl esters thereof, oxycarboxylic acids such as p-oxybenzoic acid or lower alkyl esters thereof, propylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, etc. And the like.

If the degree of polymerization of the polyethylene naphthalate used in the present invention is too low, the mechanical properties deteriorate, so that the intrinsic viscosity is preferably 0.40 or more. Further 0.45
~ 0.9 is preferred. In the present invention, the particles to be mixed with polyethylene naphthalate include, for example, silicon dioxide, aluminum oxide, titanium dioxide, kaolin, calcium carbonate, magnesium oxide, talc, zeolite, lithium fluoride, barium sulfate, carbon black, and JP-B-59. And a heat-resistant polymer fine powder described in JP-A-5216. These particles may be used alone or in combination of two or more.

In the present invention, the method for incorporating particles into polyethylene naphthalate is not particularly limited, and a known method can be employed. For example, it can be added at any stage of producing polyethylene naphthalate, but is preferably added as a slurry dispersed in ethylene glycol or the like at the stage of esterification or at the stage after the end of the transesterification reaction and before the start of the polycondensation reaction. The polycondensation reaction may proceed. Also, a method of blending a polyethylene naphthalate raw material with a slurry of particles dispersed in ethylene glycol or water using a kneading extruder with a vent, or using a kneading extruder, drying the particles and the polyethylene naphthalate raw material Is carried out by a method of blending.

In the present invention, the particle size of the particles is not particularly limited, but is preferably in the range of 0.05 to 2 μm, more preferably 0.05 to 1.5 μm, and particularly preferably 0.05 to 1 μm. In the present invention, the content of the particles in polyethylene naphthalate is not particularly limited,
For example, 0.05 to 10% by weight, preferably 0.1 to 5%
% By weight, more preferably 0.1 to 3% by weight.

Next, a method for producing a polyethylene naphthalate film will be specifically described, but the film of the present invention is not limited to the following production examples. That is, using the polyethylene naphthalate raw material described above, using an extruder, polyethylene naphthalate is melt-extruded into a sheet at 290 to 330 ° C. from a die, and 40 to 40 ° C.
A method of obtaining an unstretched sheet by cooling and solidifying with a cooling roll at 80 ° C. is preferred. In this case, in order to improve the flatness of the sheet, it is necessary to increase the adhesion between the sheet and the rotary cooling drum, and the electrostatic application adhesion method and / or the liquid application adhesion method are preferably employed.

The amorphous sheet obtained in this manner is later processed at 130 to 170 ° C. in the vertical and horizontal directions at an area magnification of 4 to 20.
Biaxially or sequentially and simultaneously
A method of performing heat treatment at 80 to 270 ° C. can be used. When stretching in the longitudinal and transverse directions, each may be stretched in one step, if necessary, may be stretched in multiple steps, or a heat treatment section for relaxing the orientation may be provided between the multiple steps. Further, after the biaxial stretching, the film may be stretched again before being subjected to the next heat treatment step. In particular, in order to increase the strength, after the biaxial stretching, re-stretching at a temperature of 140 to 200 ° C. in the longitudinal and transverse directions by 1.05 to 4.0 times is performed.
A method of heat treatment is often used.

A so-called in-line coating for treating the film surface during the stretching step can be applied. Although it is not limited to the following, the antistatic property, the slip property,
For the purpose of improving the adhesiveness, improving the secondary workability, etc., water-soluble,
Treatment with a coating agent such as an aqueous emulsion or an aqueous slurry can be performed. Also, during the stretching step,
Before or after stretching, one or both surfaces of the film may be subjected to a corona discharge treatment to improve the adhesion to secondary processing or the like on the film.

In the present invention, it is essential to have a modified copolymerized polyester layer containing particles. The modified copolyester is not particularly limited as long as it is a modified copolyester in which a part of the copolyester is substituted with another copolyester, but is preferably modified with urethane, urethane acrylate, or epoxy.

As a method for modifying the copolymerized polyester, for example, when the copolymerized polyester is polymerized, a monomer such as urethane, urethane acrylate, epoxy or the like, a monomer, a polymer, or the like is added to perform modification. Method, a method of blending monomers such as urethane, urethane acrylate, epoxy and the like, a monomer, a polymer, and the like with a copolymerized polyester, and using a mixing extruder or the like to perform heating and mixing for modification. No. In addition, as a component which comprises a copolymer polyester, the following dicarboxylic acid components and glycol components can be illustrated. That is, as the dicarboxylic acid component, terephthalic acid, isophthalic acid, phthalic acid, sebacic acid, adipic acid, oxycarboxylic acid (for example, P-
Oxybenzoic acid and the like), and the glycol component is ethylene glycol diethylene glycol,
Examples include triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, butanediol, and the like.

In the present invention, the modified copolymerized polyester layer may contain components such as other polymers, but it is necessary that the modified copolymerized polyester be the main component. In the present invention, it is necessary that the modified copolymerized polyester layer contains particles. Such particles include inorganic particles and organic particles. Examples of the inorganic particles include oxide particles such as silicon dioxide, aluminum oxide, and titanium oxide. Examples of the organic particles include monodisperse crosslinked polymer particles and JP-B-59-52.
Organic particles such as heat-resistant polymer fine powder as described in JP-A No. 16 can be mentioned.

A typical example of the monodisperse crosslinked polymer particles mentioned above is a fine spherical polymer powder having an appropriate crosslinked structure, and one aliphatic unsaturated unsaturated compound in the molecule. A copolymer of a monovinyl compound (X) having a bond and a compound (Y) having two or more aliphatic unsaturated bonds in a molecule as a crosslinking agent can be exemplified. In this case, such a copolymer may have a group capable of reacting with the polyester.

Compound (X) which is one component of the copolymer includes acrylic acid, methacrylic acid, and their methyl or glycidyl esters, maleic anhydride and its alkyl derivatives, vinyl glycidyl ether, vinyl acetate, styrene, and alkyl-substituted compounds. Styrene and the like can be mentioned. Examples of the compound (Y) include divinylbenzene, divinylsulfone, and ethylene glycol dimethacrylate. One or more of each of the compounds (X) and (Y) is used, but a compound having ethylene or a nitrogen atom may be copolymerized.

In the present invention, it is particularly preferable to select the composition so that the particles can be easily deformed from among them. In order to achieve this, concretely, the glass transition temperature of the crosslinked polymer is lowered. Is 95 ° C or less, preferably 85 ° C
Hereinafter, the copolymerization component, in particular, the compound (X) may be selected so that the temperature is more preferably 75 ° C. or lower. More specifically, when a polymer is obtained only with the copolymer component,
It is preferable to introduce a compound whose glass transition temperature is 0 ° C. or lower. Examples of such compounds include an alkyl ester of acrylic acid having 2 to 4 carbon atoms, an alkyl ester of methacrylic acid having 6 to 12 carbon atoms, and a p-position having 6 to 1 carbon atoms.
Examples include, but are not limited to, styrene derivatives having two alkyl substituents.

The degree of cross-linking also greatly affects the ease of deformation of the particles. In the present invention, it is preferable that the degree of cross-linking is relatively low as long as heat resistance is acceptable. Specifically, the weight ratio of the component (Y) during the copolymerization is 0.5 to 20%,
Further, the content is preferably in the range of 1 to 15%, particularly 1 to 10%. In the present invention, the method for blending the particles with the modified copolymerized polyester is not particularly limited, and a known method can be employed. For example, particles can be added at any stage of producing the modified copolymerized polyester. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a modified copolymerized polyester raw material using a kneading extruder with a vent, or a method of blending a dried copolymerized particle with a modified copolyester using a kneading extruder. It is carried out by a method of blending with a polyester raw material. Further, at the stage of dissolving the modified copolymerized polyester in an organic solvent to form a coating, a method of adding particles to the solvent or a method of adding particles to a modified copolymerized polyester solution previously dissolved in an organic solvent can also be preferably employed. .

In the present invention, one example of a method of laminating a modified copolymerized polyester layer containing particles on at least one surface of a polyethylene naphthalate film will be described. That is, it is carried out by a method in which a composition dissolved and / or dispersed in a solvent is applied to the surface of a polyethylene naphthalate film and dried. The application method is not particularly limited, but a reverse roll coating method, a gravure roll coating method, a rod coating method, an air knife coating method, or the like can be employed. The applied composition is dried by, for example, an infrared heater, a hot air oven, or the like as a heat source.

The content of particles in the modified copolymerized polyester layer is usually 0.1 to 30% by weight, preferably 0.5 to 15% by weight.
%, More preferably 1 to 8% by weight. If the content of the particles is less than 0.1% by weight, blocking may occur during storage of the product roll, and wrinkles may occur at the time of lamination and winding with the metallized film. When the content of the particles exceeds 30% by weight, the occurrence of blocking is reduced,
The adhesion between the dielectric film and the metallized film may be reduced. The modified copolymerized polyester layer may contain additives other than particles as long as the film properties are not impaired.

In the present invention, the coating amount of the particle-containing modified copolymerized polyester layer is not particularly limited, but is preferably in the range of 0.01 to 0.1, more preferably 0 to 0.1 in terms of the thickness ratio with respect to the laminated film. .02-0.07
Range. If the thickness ratio is less than 0.01, the adhesion to the metallized film may be deteriorated, and if it exceeds 0.1, the adhesion becomes good, but the metallized film is laminated and wound into a capacitor. Sometimes the dielectric loss tends to increase. The thickness of the laminated film of the present invention is not particularly limited, but is usually 5 to 20 μm,
Preferably it is 10 to 15 μm.

In the present invention, the adhesion between the surface of the particle-containing modified copolymerized polyester layer of the laminated film and the surface of the aluminum vapor-deposited film is 5 gf / 15 mm or more.
It is preferably from 5 to 100 gf / 15 mm, and more preferably from 10 to 50 gf / 15 mm. Such adhesive strength is 5
If it is less than gf / 15 mm, the adhesion when bonded to a metallized film tends to be poor, and impregnation used for preventing internal discharge, reinforcing lead wires, improving moisture resistance, and the like. The agent infiltrates the vapor deposition electrode of the metallized film and causes cracks in the vapor deposition electrode due to curing shrinkage, which may cause undesired phenomena for the capacitor, such as a decrease in the capacitance of the capacitor, a shortened life, and destruction. Also,
If this value is too high, it has little adverse effect on the capacitor characteristics, but blocking tends to occur during the production of the laminated film, which may affect the winding workability.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. The physical property measurement methods used in the present invention are as follows. In the examples, “parts” and “%” mean “parts by weight” and “% by weight”, respectively.

(1) Thickness ratio t of laminated film thickness and particle-containing modified copolymerized polyester layer t After a sample film piece was fixed and molded with epoxy resin,
The film was cut with a microtome, and the cross section of the film was observed with a transmission electron microscope. In the cross section, the interface is observed by light and dark almost parallel to the film surface. The distance between the interface and the film surface was determined by integration for one transmission electron micrograph, and this was performed for at least 50 photographs, and 10 points were measured from the thicker one and 10 points from the thinner one. The arithmetic mean of the points was taken as the thickness of the laminated film. Next, the thickness ratio of the particle-containing modified copolymerized polyester layer was calculated by the following equation.

[0027]

## EQU1 ## Thickness ratio t of the particle-containing modified copolyester layer
= Total thickness of modified copolymerized polyester layer containing particles / Total thickness of laminated film

(2) Adhesion Lamination with the vapor-deposited surface of an aluminum-deposited polyester film
Weight of the film-containing modified copolyester layer
Combined, temperature 120 ° C, pressure 1kg / cm ^TwoCondition
For 3 seconds. Thereafter, at 23 ° C.-50
% RH for more than 24 hours
Cut to 15mm width and use a tensile tester
10 points of force when peeled off at a speed of 300 mm / min.
Of the sample, and the average value is taken as the adhesive strength.
Was.

(3) Evaluation of Blocking Property The polyester film surface of the laminated film and the particle-containing modified copolymerized polyester layer surface were superimposed on each other and 10 kg /
Treated in a 40 ° C.-80% RH wet heat oven for 20 hours with a pressure of cm ² . Then, the laminated film was peeled off at a speed of 500 mm / min using a tensile tester, and the presence or absence of blocking was visually observed.

Production Example 1 (monodisperse crosslinked polymer particles G1) 0.36 parts of potassium persulfate as a water-soluble polymerization initiator and sodium lauryl sulfate as a dispersion stabilizer (trade name: Emar O Kao Co., Ltd.) in 120 parts of deionized water 0.035
After adding and dissolving uniformly, 10.8 parts of styrene,
1.2 parts of divinylbenzene were added. Polymerization was carried out at 70 ° C. to 75 ° C. while stirring under a nitrogen gas atmosphere, and after 6 hours, monodisperse crosslinked polymer particles G1 were obtained. The average particle size of the obtained particles is 0.62 μm, and the particle size distribution value (r) is 1.2.
It was 3.

Production Example 2 (monodisperse crosslinked polymer particles G2) 0.32 parts of potassium persulfate as a water-soluble polymerization initiator and sodium lauryl sulfate as a dispersion stabilizer (trade name: Emar O Kao Co., Ltd.) in 120 parts of deionized water 0.000
After adding 4 parts by weight and dissolving uniformly, a mixed solution of 7 parts of ethylene glycol dimethacrylate, 2 parts of methyl methacrylate and 1 part of divinylbenzene was added. The temperature was raised to 70 ° C. while stirring in a nitrogen gas atmosphere, and polymerization was carried out for 6 hours. The conversion was 99%, and the average particle size of the obtained crosslinked polymer particles was 0.27 μm.

Further, a uniform mixed solution of 60 parts of demineralized water, 3.5 parts of ethylene glycol dimethacrylate, 1 part of methyl methacrylate and 0.5 part of divinylbenzene was added to the reaction system, and polymerization was carried out at 70 ° C. for 6 hours. Reaction rate is 9
At 9.8%, the average particle size of the obtained monodispersed crosslinked polymer particles G2 was 0.31 μm, and the particle size distribution value (r) was 1.22.

Production Example 3 (Heat-resistant polymer fine powder H) 100 parts of methyl methacrylate, 25 parts of divinylbenzene
Parts, ethyl vinyl benzene 22 parts, benzoyl peroxide 1
Parts and 100 parts of toluene were dispersed in 700 parts of water. Next, the mixture was heated to 80 ° C. in a nitrogen atmosphere and polymerized while stirring for 6 hours. The average particle size of the obtained crosslinked polymer granules having an ester group was about 0.1 mm.
The resulting polymer was washed with demineralized water and extracted twice with 500 parts of toluene to remove a small amount of unreacted monomer and linear polymer. Next, the obtained polymer granules were roughly pulverized with an atomizer and then finely pulverized with a sand grinder to obtain a crosslinked polymer fine powder H having an average particle size of 0.37 μm.

Production Example 1 (polyethylene naphthalate A) 100 parts of dimethyl naphthalene-2,6-dicarboxylate,
60 parts of ethylene glycol and 0.09 part of magnesium acetate tetrahydrate were placed in a reactor, heated and heated, and methanol was distilled off to carry out a transesterification reaction. The temperature was raised to 230 ° C. in 4 hours from the start of the reaction. Then, the transesterification was substantially completed. Subsequently, the average particle size is 1.45μ.
m of silicon dioxide particles as an ethylene glycol slurry, 0.03 part of phosphoric acid and 0.035 part of antimony trioxide are added, and a polycondensation reaction is carried out by a conventional method to obtain an intrinsic viscosity of 0.50. Silicon dioxide particle content 0.1
% By weight of polyethylene naphthalate was obtained. The obtained polymer was subjected to solid phase polymerization at 0.3 mmHg and 240 ° C. for 8 hours to obtain polyethylene naphthalate A having an intrinsic viscosity of 0.65.

Production Example 5 (Modified Copolyester U1) In Production Example 4, the dicarboxylic acid component was 50 parts of dimethyl terephthalate and 50 parts of dimethyl isophthalate, and the glycol component was ethylene glycol / neopentyl glycol = 50% / 50% ( (Compounding ratio), and a copolymerized polyester was obtained in the same manner as in Production Example 4 except that no particles were added. Diisocyanate was reacted with the obtained copolyester to synthesize copolyester urethane. The average molecular weight of the modified copolymer polyester U1 is 1
5000, and the glass transition temperature Tg was 59 ° C.

Production Example 6 (Copolyester B2) In Production Example 4, ethylene glycol / tetraethylene glycol = 50% / 50% as a glycol component
(Example 4) Except that the composition was changed to (mixing ratio) and no particles were added.
In the same manner as in the above, copolymerized polyester B2 having an average molecular weight of 15,000 was obtained. The glass transition temperature Tg of the obtained copolymerized polyester was 21 ° C.

Production Example 7 (Paint P1) In a mixed solvent of 50 parts of toluene and 50 parts of methyl ethyl ketone, 30 parts of the modified copolymerized polyester U1 was added and dissolved to prepare a paint P1. Production Example 8 (Paint P2) In a mixed solvent of 80 parts of toluene and 20 parts of methyl ethyl ketone, 30 parts of a copolymerized polyester B2 was added and dissolved to obtain a paint P2.

Production Example 9 (Polyethylene Naphthalate Film A) Polyethylene naphthalate A was dried at 180 ° C. for 4 hours in an inert gas atmosphere, melt-extruded at 290 ° C. by a melt extruder, and subjected to an electrostatic contact method. Surface temperature 40 ° C
And cooled and solidified on a cooling roll set to obtain an unstretched sheet. The obtained sheet was stretched 3.6 times in the longitudinal direction at 130 ° C. Next, the film was guided to a tenter and stretched 3.6 times in the horizontal direction at 135 ° C., and then heat-set at 240 ° C. to obtain a polyethylene naphthalate film A having a thickness of 12 μm.

Example 1 Silicon dioxide particles having an average particle size of 1.45 μm were added so as to be 3% by weight with respect to the solid content in the coating material P1, and the amount of coating after drying on the surface of the polyethylene naphthalate film A was It was coated with a gravure roll to a concentration of 0.5 g / m ² and dried to obtain a laminated film.

Example 2 A heat-resistant polymer fine powder H was added so as to be 1.5% by weight with respect to the solid content in the coating material P1, and the amount of the dried coating on the surface of the polyethylene naphthalate film A was 0%. 0.5 g / m
^The resultant was applied with a gravure roll so as to obtain No. ^2, and dried to obtain a laminated film.

Example 3 Monodisperse crosslinked polymer particles G1 were added so as to be 1.5% by weight with respect to the solid content in the coating material P1, and the amount of the coating after drying was applied to the surface of the polyethylene naphthalate film A. 0.5
g / m ² with a gravure roll, dried,
A laminated film was obtained.

Example 4 Monodisperse crosslinked polymer particles G2 were added so as to be 1.5% by weight with respect to the solid content of the coating material P1, and the amount of the coating after drying on the surface of the polyethylene naphthalate film A was 0.5
g / m ² with a gravure roll, dried,
A laminated film was obtained.

Example 5 While the paints P1 to P2 were mixed at a ratio of 90:10, silicon dioxide particles having an average particle size of 1.45 μm were added so as to be 3% by weight based on the solid content in the paint. And the amount of coating on the surface of the polyethylene naphthalate film A after drying was 0.
It was applied with a gravure roll so as to be 5 g / m ² and dried to obtain a laminated film.

Example 6 While the paints P1 to P2 were mixed at a ratio of 90:10, heat-resistant polymer fine powder H was added so as to be 1.5% by weight with respect to the solid content in the paint. It was applied to the surface of the polyethylene naphthalate film A with a gravure roll so that the applied amount after drying was 0.5 g / m ^2, and dried to obtain a laminated film.

Example 7 Silicon dioxide particles having an average particle size of 1.45 μm were added so as to be 3% by weight with respect to the solid content in the paint P1, and the amount of the coating after drying on the surface of the polyethylene naphthalate film A was adjusted. It was applied with a gravure roll so as to have a weight of 0.3 g / m ² and dried to obtain a laminated film.

Example 8 Silicon dioxide particles having an average particle size of 1.45 μm were added so as to be 3% by weight with respect to the solid content in the coating material P1, and the amount of the coating after drying on the surface of the polyethylene naphthalate film A was adjusted. It was applied with a gravure roll so as to be 0.8 g / m ² and dried to obtain a laminated film.

Comparative Example 1 The coating material P1 was applied to the surface of the polyethylene naphthalate film A with a gravure roll so that the coating amount after drying was 0.5 g / m ² , followed by drying to obtain a laminated film. Comparative Example 2 The coating material P2 was applied to the surface of the polyethylene naphthalate film A with a gravure roll so that the coating amount after drying was 0.5 g / m ^2, and dried to obtain a laminated film.

Comparative Example 3 A laminated film was obtained in the same manner as in Example 5, except that no particles were added to the paint. Comparative Example 4 While the paints P1 to P2 were mixed at a ratio of 10:90, silicon dioxide having an average particle size of 1.45 μm was added so that the weight ratio became 0.5% by weight based on the solid content in the paint, and polyethylene was added. The coating amount after drying on the surface of the naphthalate film A is 0.5
g / m ² with a gravure roll, dried,
A laminated film was obtained.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

According to the laminated film for a capacitor of the present invention, it is possible to prevent wrinkles from being generated at the time of lamination and winding with a metallized film, and to sufficiently adhere the dielectric film to the metallized film. The resulting capacitor is excellent in performance such as prevention of destruction and life of the capacitor, and is extremely useful particularly when used as a dielectric film for a high-voltage capacitor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01G 4/20 B32B 27/20 Z 4/015 27/36 // B32B 27/20 H01G 4/20 27 / 36 4/24 321B 321D F-term (reference) 4F100 AA17A AA20 AB10 AH01A AK25A AK41A AK42B AK51A AK53A AL06A BA02 BA16 DE01A EH66 GB41 JK06 JL11 YY00 YY00A 4J002 BC022 BF012 CF03 DE03FA05BC023 EE37 FF14 FF15 FG06 FG22 FG34 FG36 FG46 MM24 PP03 PP10

Claims (5)

[Claims] 1. A laminated film for a capacitor, comprising a modified copolymerized polyester layer containing particles on at least one side of a polyethylene naphthalate film. 2. The laminated film for a capacitor according to claim 1, wherein the particles in the modified copolymerized polyester layer are oxide particles or organic particles. 3. The laminated film for a capacitor according to claim 1, wherein the content of the particles in the modified copolymerized polyester layer is 0.1 to 30% by weight. 4. The adhesive strength between the surface of the modified copolymerized polyester layer and the surface of the aluminum vapor-deposited film is 5 gf / 1.
The laminated film for a capacitor according to any one of claims 1 to 3, wherein the thickness is 5 mm or more. 5. The modified copolymerized polyester is a urethane,
A copolymer polyester modified with urethane acrylate or epoxy, characterized in that:
5. The laminated film for a capacitor according to any one of 4.