JPH07220975A - Metallized laminate film for capacitor - Google Patents

Abstract

PURPOSE:To provide an easy-to-peel, metallized laminate film which is useful for manufacturing a capacitor whose insulation film is an extremely thin polyethylene-2,6-naphtalene dicarboxylate film. CONSTITUTION:A metallized laminate film for a capacitor comprises a 1 to 2mum-thick polyethylene-2,6-naphthalene dicarboxylete film with both lengthwise and breadthwise Young's modulus of 600kg/mm<2> which is laminated on at least one side of a polyolefine resin film whose double refraction is 0.01 or below at adhesion strength of 0.1 to 2.0g/cm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor-deposited laminated film for capacitors, and more particularly to polyethylene-based film.
The present invention relates to a vapor-deposited laminated film for a capacitor, which is suitable for efficiently manufacturing a capacitor using an extremely thin insulating film made of a 2,6-naphthalene dicarboxylate film.

[0002]

2. Description of the Related Art A capacitor is manufactured by a method in which an insulating film and a metal thin film are superposed and wound, a method in which a metal is vapor-deposited on the surface of the insulating film, and this is wound, and the biaxial film is used as the insulating film. Organic polymer films such as stretched polyethylene terephthalate film and biaxially stretched polypropylene film are used.

In recent years, along with the miniaturization and weight reduction of electric devices, capacitors have been further miniaturized, and therefore, the insulating film used therefor is required to be thinner.

The thickness of the insulating film currently in practical use is 1.5 μm for polyethylene terephthalate film.
It is a degree.

However, when the film thickness is made thinner than the conventional one in order to downsize the capacitor or increase the capacity, breakage frequently occurs in the film manufacturing process, and it becomes very difficult to obtain a product. There is.

Furthermore, since a thin film has a soft waist, it is difficult to handle, and wrinkles are easily generated in the film in the vapor deposition process. Further, in the process of cooling the film heated by vapor deposition with a cooling drum, the film causes poor adhesion to the cooling drum due to this wrinkle and causes cooling spots, resulting in poor flatness such as wakame due to heat shrinkage spots (below. Sometimes called "heat loss") occurs. Conventionally, the wrinkle of the film is prevented by increasing the tension in the longitudinal direction, but when the film becomes thin, the film tends to stretch due to tension, and problems such as vapor deposition and the end surface of the film passing through slits become wakame-like. is there.

Various proposals have been made to solve these problems. For example, for the purpose of eliminating the breakage of the ultrathin polyethylene terephthalate film in the film manufacturing process, a method of laminating the ultrathin polyethylene terephthalate film with a film of a different type in advance to form a thick film, and stretching the film is used. Proposed. For example, Japanese Patent Application Laid-Open No. 58-5226 discloses a method of co-extruding a polyolefin and polyethylene terephthalate into a laminated sheet, stretching the laminated sheet, and then peeling off the polyethylene terephthalate film to form an ultrathin film. ing. As described above, there are many other methods of laminating different kinds of polymers and peeling them after the film formation to form an ultrathin film. For example, JP-A-60-163419, 58-132520, 58-13.
A similar method is proposed in 6417, 57-176125, 52-37982 and the like.

However, the polyethylene terephthalate film, as described above, has problems such as insufficient rigidity of the film after peeling and heat loss, which is not an essential improvement in the vapor deposition process.

Therefore, as an improvement measure against the essential problems caused by the thinning of the film, that is, the difficulty of handling and the loss of heat during vapor deposition, biaxially oriented polyethylene-2,6-naphthalenedicarboxylate having a high elastic modulus is used. A method of using a rate film as an insulating film is proposed in, for example, Japanese Patent Laid-Open No. 63-140512.

However, there is no end to the recent demand for miniaturization of electric and electronic circuits, and there is a further demand for thinner capacitor films.
Biaxially Stretched Polyethylene Proposed in Japanese Patent No. 40512
Even in the case of 2,6-naphthalenedicarboxylate film, the problems described above have been highlighted.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to improve the productivity of a film having the above-mentioned drawbacks improved, that is, an ultrathin film, and to prevent the generation of defects such as heat loss in the step of depositing a metal. To provide a metal vapor-deposited laminated film for use.

[0012]

The object of the present invention is to:
According to the present invention, a polyolefin resin film having a birefringence of 0.01 or less has a Young's modulus of 600 kg / mm ² or more and a thickness of 0.
A vapor-deposited laminated film for capacitors, wherein a polyethylene-2,6-naphthalene dicarboxylate film having a thickness of 1 to 2 μm is laminated with an adhesion strength of 0.1 to 2.0 g / cm, and a metal is vapor-deposited thereon. Also, the polyolefin resin film was peeled off from the laminated film, and the Young's modulus in both the longitudinal and transverse directions was 600 kg / mm ²
With the above, polyethylene-2,6 having a thickness of 0.1 to 2 μm
-Achieved by a vapor deposited laminated film for capacitors in which metal is vapor deposited on one side of a naphthalene dicarboxylate film.

The polyethylene-2,6-naphthalenedicarboxylate according to the present invention may be any copolymer whose repeating units are substantially composed of ethylene-2,6-naphthalenedicarboxylate units and is not copolymerized. Not only polyethylene-2,6-naphthalenedicarboxylate but also ethylene-2,6-naphthalenedicarboxylate in which 10% or less, preferably 5% or less of the number of repeating units are replaced by other components It includes polymers as well as polymer mixtures.

In general, polyethylene-2,6-naphthalenedicarboxylate is produced by reacting naphthalene-2,6-dicarboxylic acid or its ester-forming derivative with ethylene glycol or its ester-forming derivative in the presence of a catalyst. However, in the above-mentioned polyethylene-2,6-naphthalenedicarboxylate copolymer or mixture, an appropriate one or two kinds of polyethylene-2,6-naphthalenedicarboxylate may be prepared before the completion of the polymerization of the polyethylene-2,6-naphthalenedicarboxylate.
It can be produced by adding at least one kind of third component (modifying agent) and copolymerizing or mixing them.

Preferred third component is a compound having a divalent ester-forming functional group such as oxalic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,7-dicarboxylic acid, succinic acid. Dicarboxylic acids such as diphenyl ether dicarboxylic acid or lower alkyl esters thereof, oxycarboxylic acids such as P-oxybenzoic acid and P-oxyethoxybenzoic acid or lower alkyl esters thereof, and dihydric alcohols such as propylene glycol and tetramethylene glycol. And other compounds.

Polyethylene-2,6-naphthalenedicarboxylate may be obtained by blocking the terminal hydroxyl group and / or carboxyl group with a monofunctional compound such as benzoic acid or methoxypolyalkylene glycol. It may be modified with a very small amount of a trifunctional or tetrafunctional ester-forming compound such as glycerin or pentaerythritol within a range where a substantially linear copolymer can be obtained.

The metal deposited by vapor deposition on one side of the polyethylene-2,6-naphthalene dicarboxylate film is not particularly limited, and for example, aluminum,
Examples include zinc, copper and tin. Also, regarding the method of vapor deposition, generally used methods such as a vapor deposition method in which a metal is heated / melted / vaporized by a heater and then deposited on a substrate, and a collision of an inert gas such as accelerated metal is used. A sputtering method for depositing a vaporized substance on a substrate,
CVD method for growing a metal by reacting a raw material gas on a substrate, MOCV using an organic metal gas as a starting raw material
D method etc. are mentioned.

The polyolefin resin in the present invention means
It is a resin composed of an olefin polymer, a copolymer, or a mixture thereof, and examples thereof include low-density polyethylene, high-density polyethylene, linear polyethylene, polypropylene, and polybutene. Of these, polypropylene or polypropylene copolymer is most preferable.

The term "polypropylene" as used herein means that the repeating units are substantially composed of propylene units. Not only polypropylene which is not copolymerized but also 10% or less of the number of repeating units is preferable. Up to 5% include copolymers where up to 5% is replaced by other components such as ethylene, butene, etc., as well as polymer mixtures.

In the present invention, the laminated film has a structure in which a polyethylene-2,6-naphthalene dicarboxylate film is laminated on at least one side of a polyolefin resin film, and a metal is vapor-deposited on the laminated film. The polyethylene-2,6-naphthalenedicarboxylate film is biaxially oriented (longitudinal direction and lateral direction) and has a thickness of 0.1 to 2.0 μm, preferably 0.
The film has a thickness of 1 to 1.5 μm, more preferably 0.1 to 1.0 μm. If the film thickness is less than 0.1 μm, the polyethylene-2,6-naphthalenedicarboxylate film may be broken during the step of peeling and removing the polyolefin resin film from the metal-deposited polyethylene-2,6-naphthalenedicarboxylate film. If it is frequently and not practical, on the other hand, when it is thicker than 2 μm, the film alone can be handled, and therefore it is not necessary to form a laminate as in the present invention.

Further, the polyethylene-2,6-naphthalenedicarboxylate film must have Young's modulus in the longitudinal and transverse directions of 600 kg / mm ² or more. If the Young's modulus in the longitudinal direction is lower than 600 kg / mm ² , the film becomes thinner as the capacitor becomes smaller and lighter, and the stiffness becomes weaker (decrease in rigidity). Metal-deposited polyethylene after peeling from the polypropylene film of the support. -2
It becomes difficult to handle the 6-naphthalene dicarboxylate film.

The Young's modulus in the lateral direction is 600 kg / m.
When it is lower than m ² , stiffness in the horizontal direction (waist) is weak and fine wrinkles are easily generated in the vertical direction, which is not preferable.

Young's modulus in the vertical and horizontal directions is 600 kg each
/ Mm in the production of ^two or more polyethylene terephthalate film, it is necessary to increase the longitudinal and transverse direction stretching ratio, but this manufacturing method, breakage during film according film thickness decreases occurs frequently, producing Sex is extremely reduced.

However, polyethylene-2,6-naphtha
In the range carboxylate film, polyethylene
High even at the same stretch ratio as the phthalate film
It has an advantage that Young's modulus can be obtained. For example, vertical
The direction draw ratio is 3.6 times, and the transverse draw ratio is 3.9.
When doubled, polyethylene terephthalate film
Young's modulus in the vertical and horizontal directions is 530 kg / mm²To a degree
On the other hand, polyethylene-2,6-naphthalenedica
600 kg / mm for ruboxylate film ²More than
Young's modulus can be easily obtained. In addition, polyethylene
2,6-naphthalenedicarboxylate has a stretchable film-forming property.
Excellent, higher draw ratio than polyethylene terephthalate
The advantage that it is possible and easy to obtain a high strength film
Have.

As the biaxial stretching method, for example, an unstretched film is stretched in the machine direction and then stretched in the transverse direction, that is, a so-called longitudinal-transverse sequential stretching method, and simultaneous stretching in the longitudinal and transverse directions is performed simultaneously.
There are an axial stretching method, a re-stretching method in which a normal biaxially stretched film is stretched again in the machine direction or the transverse direction, and further in the machine direction and the transverse direction at the same time. The stretching method in the present invention includes any of these methods. May be.

A metal must be vapor-deposited on one surface of the oriented polyethylene-2,6-naphthalene dicarboxylate film. The vapor deposition of the metal layer makes it very easy to peel the laminated film in the step of peeling and removing the polyolefin resin film as the base material from the metal vapor-deposited polyethylene-2,6-naphthalene dicarboxylate film. The thickness of the deposited metal layer is 0.03 to
0.3 μm, preferably 0.05 to 0.2 μm. If it is thinner than this, the effect of reducing peeling is weakened, and if it is thicker than this, the self-healing function of the capacitor is deteriorated, which is not preferable.

The polyolefin resin film which is brought into close contact with the surface of the polyethylene-2,6-naphthalenedicarboxylate film opposite to the surface on which the metal layer is vapor-deposited preferably has a thickness of 5 to 30 μm. The polyolefin resin film has a birefringence of 0.01 or less, preferably 0.008 or less, particularly preferably 0.005 or less.
If the birefringence exceeds 0.01, polyethylene-2,6-
This is not preferable because the polyolefin resin film is likely to be cut or torn when the naphthalene dicarboxylate film and the polyolefin resin film are peeled off.

The adhesion strength between the polyethylene-2,6-naphthalenedicarboxylate film and the polyolefin resin film (hereinafter sometimes referred to as "adhesion") is in the range of 0.1 to 2.0 g / cm. It is necessary and preferably in the range of 0.1 to 0.8 g / cm.
If the adhesive force is lower than this, peeling may occur during transport during film formation, and the portion may be broken or broken, which is not preferable. On the other hand, if the adhesion is higher than this, polyethylene-2,
In the step of peeling the 6-naphthalene dicarboxylate film and the polyolefin resin film, polyethylene-
It is not preferable because the 2,6-naphthalene dicarboxylate film is cut or broken.

As a method for keeping the adhesive force between the polyethylene-2,6-naphthalenedicarboxylate film and the polyolefin resin film within the above range, the polyethylene-2,6-naphthalenedicarboxylate film and / or the polyolefin resin film may be used. 0.001
It is preferable to add a non-particulate lubricant in an amount of 1 to 1% by weight, preferably 0.005 to 0.5% by weight.

The non-particulate lubricant means a substance which has a melting point or a softening point of 200 ° C. or lower even if it is a liquid or a solid at room temperature and imparts lubricity to the film. When two or more kinds of these substances are contained in the film, the total amount thereof should be within the above content range.

Specific examples of this non-particulate lubricant include the following. A. Aliphatic hydrocarbon liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyethylene wax,
Polypropylene wax etc.

B. Higher fatty acid or its metal salt Stearic acid, calcium stearate, hydroxystearic acid, hydrogenated oil, sodium montanate, etc.

C. Aliphatic amides Stearic acid amide, oleic acid amide, erucic acid amide, ricinoleic acid amide, behenamide, methylenebisstearamide and the like.

D. Fatty acid ester n-butyl stearate, methyl hydroxy stearate, myricyl serotinate, higher alcohol fatty acid ester, ester wax and the like.

E. Fatty acid ketone, ketone wax, etc.

F. Fatty alcohol lauryl alcohol, stearyl alcohol, myristyl alcohol, cetyl alcohol, etc.

G. Partial ester of fatty acid and polyhydric alcohol Glycerin fatty acid ester, hydroxystearic acid triglyceride, sorbitan fatty acid ester, etc.

H. Nonionic surfactant Polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, polyoxyethylene alkylamide, polyoxyethylene fatty acid ester, etc.

I. Silicone oil Linear methyl silicone oil, Methylphenyl silicone oil,
Modified silicone oil etc.

J. Fluorine-based surfactants Fluoroalkylcarboxylic acid, perfluoroalkylcarboxylic acid, monoperfluoroalkylethyl phosphate, perfluoroalkyl sulfonate, etc.

The average particle size is from 0.001 μm to 5.0
μm fine particles, particularly inorganic particles such as dry silica, wet silica, zeolite, calcium carbonate, calcium phosphate, kaolin, kaolinite, clay, talc, titanium oxide, alumina, zirconia, aluminum hydroxide, etc., are added to polyethylene-2,6- Naphthalene dicarboxylate and / or polyolefin resin film having
If the content of 01 wt% to 0.5 wt% is included, the effect of the non-particulate lubricant can often be synergistically enhanced. In the present invention, the laminated film is obtained by co-extruding polyethylene-2,6-naphthalenedicarboxylate and a polyolefin resin into an unstretched laminated sheet, which is biaxially stretched, and then polyethylene having a melting point higher than that of the polyolefin resin. It can be preferably produced by heat-treating at a temperature lower than the melting point of -2,6-naphthalenedicarboxylate and then cooling to room temperature. At that time, the thickness of each sheet layer of the unstretched laminated sheet is such that the thickness of each film layer of the laminated film after the biaxial stretching treatment is the above-mentioned thickness, and the stretching and heat treatment are the above-mentioned Young's modulus, It may be carried out under the condition that physical properties such as birefringence are obtained.

The metallized film capacitor is wound by a method of depositing a metal such as zinc on a biaxially stretched polyethylene-2,6-naphthalene dicarboxylate film, winding it, and then applying a metallikon to the end face of the deposited portion. Method for preparing electrodes, lamination method: Biaxially oriented polyethylene-2,6-
A method is known in which a metal thin film layer is formed on the surface of a naphthalene dicarboxylate film, a derivative layer is coated on the surface of the naphthalene dicarboxylate film, the film is wound, and then metallicon is applied after cutting.

In the present invention, a metal thin film is vapor-deposited on the polyethylene-2,6-naphthalenedicarboxylate film in a state where the support polyolefin resin film and the polyethylene-2,6-naphthalenedicarboxylate film are laminated. After forming by the method described above, by winding and removing the metallized polyethylene-2,6-naphthalene dicarboxylate film while peeling off the polyolefin resin film of the support, it is possible to stably form the element winding for the capacitor.

The polyethylene-2,6-naphthalenedicarboxylate film has a much smaller amount of oligomers than the polyethylene terephthalate film, does not pollute the cooling drum during vapor deposition, and improves workability. There are advantages such as that, in the production of metallized film capacitors polyethylene-
The superiority of using a 2,6-naphthalene dicarboxylate film as a dielectric layer base is outstanding.

The polyethylene-2,6-naphthalenedicarboxylate film of the present invention contains 0.1 to 2.0 μm.
m, preferably 0.1 to 1.5 μm, more preferably 0.1 to 1.0 μm, and biaxially oriented polyethylene having a Young's modulus of 600 kg / mm ² or more in the longitudinal and transverse directions, respectively. A 2,6-naphthalene dicarboxylate film having a metal vapor deposited on one surface thereof,
Further, by adopting a structure in which the polyolefin resin film is laminated on the surface on the opposite side with an adhesive strength of 0.1 to 2.0 g / cm, the following excellent effects can be obtained. (1) Since a vapor-deposited film of polyethylene-2,6-naphthalene dicarboxylate film having a Young's modulus of 600 kg / mm ² or more can be continuously obtained in a clean state,
It is possible to make a compact and high-capacity capacitor. (2) Workability is improved because steps such as slitting can be performed with the polyolefin resin film of the support still attached. (3) When peeling the metal-deposited polyethylene-2,6-naphthalene dicarboxylate film from the polyolefin resin film, wrinkles are not generated and the film is not broken, so that workability is improved. (4) The polyolefin resin film after peeling off the metal-deposited polyethylene-2,6-naphthalene dicarboxylate film is economical because it can be reused by crushing it again and mixing it with the original raw material. (5) By using an ultrathin metal-deposited polyethylene-2,6-naphthalene dicarboxylate film, a metallized film capacitor having excellent electrical characteristics can be obtained.

[0046]

EXAMPLES The present invention will be further described below with reference to examples.

Various physical properties and characteristics in the present invention are measured and defined as follows. (1) Film thickness The thickness of the polyethylene-2,6-naphthalene dicarboxylate film is measured by using a transmitted light type optical interference thickness measuring instrument using a visible light wavelength emission lamp with a halogen gas as a light source, and measuring the thickness of adjacent interferences. It was calculated from the stripe interval by the following formula (1).

[0048]

[Equation 1]

Here, d in the equation (1) is the thickness (nm),
λ1 and λ2 represent the peak wavelength (nm) of the interference fringes (λ1
> Λ2), n is the average refractive index of the polyethylene-2,6-naphthalenedicarboxylate film in the machine and transverse directions.

Thickness range to which the above method cannot be applied (thick material)
The film was measured for its thickness by an electronic micro. (2) Thickness of vapor-deposited metal layer The thickness of the vapor-deposited layer was calculated by measuring the value of the electric resistance using the relationship between the thickness of the vapor-deposited layer and the electric resistance thereof for each type of metal. (3) Young's modulus The polyethylene-2,6-naphthalenedicarboxylate film peeled from the polyolefin resin film of the support was cut into a sample having a width of 10 mm and a length of 150 mm, and the distance between chucks was 100 mm and the pulling speed was 10 mm / min.
The sample was pulled by an Instron type universal tensile tester under the condition of a chart speed of 500 mm / min.
Young's modulus was calculated from the tangent line of the rising portion of the obtained weight-elongation curve. (4) Adhesive strength (adhesion strength) Polyethylene-2,6-before metal deposition and after metal deposition
A laminated film of a naphthalene dicarboxylate film and a polyolefin resin film was cut into the same size as the sample at the time of measuring Young's modulus, and the polyethylene-2,6-naphthalene dicarboxylate film on the surface layer was continuously cut at a peel angle of 180 degrees. The tension applied when peeling at a speed of 2 m / min was measured. This tension T (g) becomes the adhesive force T (g / cm) as it is. (5) Melting point Using DSC, the temperature was raised at a heating rate of 20 ° C./min, and the temperature corresponding to the top of the endothermic peak associated with melting was taken as the melting point (sample: 10 mg). (6) Capacitance (C), dielectric loss tangent (tan δ) Measured according to JIS C 5102.

Example 1 The following two types of raw materials (pellets) were prepared. (1) Polyethylene-2,6 containing 0.3% by weight of a cataloid having an average particle size of 0.12 μm and an intrinsic viscosity of 0.60
-Naphthalene dicarboxylate (hereinafter sometimes referred to as "PEN") pellets. (2) Polypropylene (hereinafter sometimes referred to as “PP”) pellets containing 0.2% by weight of glycerin fatty acid ester (glycerin monostearate) and having a melting point of 160 ° C.

The PEN raw material was dried at 170 ° C. for 6 hours, supplied to an extruder, and melt-extruded at 300 ° C. On the other hand, PP
The raw material was dried at 100 ° C. for 2 hours, then supplied to another extruder, and melt-extruded at 300 ° C. like PEN. The melts are merged inside the die to form a three-layer laminated structure of PEN / PP / PEN, then discharged from the die and wound around a cooling drum kept at 50 ° C to be cooled and solidified to form a three-layer laminated sheet. And PEN layer on both outer sides is 20 μm, PP on the inner layer
The layer was 150 μm.

This sheet was heated to 130 ° C. by bringing it into contact with a roll, then stretched 3.6 times in the longitudinal direction (longitudinal direction) and immediately cooled to 60 ° C. Subsequently, it was stretched in the transverse direction by a tenter type transverse stretching device at 140 ° C. by 3.9 times, subsequently subjected to heat treatment at 210 ° C., then cooled to room temperature and wound. The film-forming process was stable, and the thickness unevenness of the obtained film was small, and a uniform three-layer film was obtained.

The thickness of the obtained laminated film was 1.4 μm for the PEN films on both outer sides and 1 for the PP film of the inner layer.
1 μm, the birefringence of the inner PP film is 0.00
It was 02. The Young's modulus in the longitudinal and transverse directions of the PEN film were 660 and 650 kg / mm ² , respectively, and the average refractive index in the longitudinal and transverse directions was 1.751. Also,
Adhesion between PEN film and PP film is 0.8g / c
It was m.

Next, this laminated film was put into a vacuum vapor deposition machine, and aluminum having a thickness of 0.08 μm was vapor-deposited on the surfaces of the PEN films on both sides under the conditions of a vacuum degree of 10 ⁻⁵ mmHg and a vapor deposition rate of 30 m / min.

When the PEN film was peeled from this vapor-deposited laminated film, no wrinkles were formed, and neither film breakage nor breakage occurred during peeling, and an ultrathin vapor-deposited PEN film was obtained in a clean state. In addition, PEN after vapor deposition
The adhesive force between the film and the PP film was 0.6 g / cm.

Separately, a vapor-deposited laminated film was slit to a width of 1 cm, and while peeling the PP film from the vapor-deposited PEN film, the aluminum film was wound so that the aluminum end faces were alternately on the outer side, and metallikon was applied to produce a capacitor element. did. The obtained capacitor has a tan δ of 0.0
037 showed good characteristics.

Example 2 0.2% by weight of polyhydric alcohol fatty acid ester was added to glycerin monostearate in PP.
A three-layer laminated film was obtained in the same manner as in Example 1 except that the addition was changed and the thickness of the PEN film obtained by cooling and solidification was 10 μm. The film-forming process was stable, and the thickness unevenness of the obtained film was small, and a uniform three-layer film was obtained.

The thickness of the obtained laminated film was 0.7 μm for both outer PEN films and 1 for the inner PP film.
1 μm, the birefringence of the inner PP film is 0.00
It was 02. Further, the Young's modulus in the longitudinal and transverse directions of the PEN film were 650 and 650 kg / mm ² , respectively, and the average refractive index in the longitudinal and transverse directions was 1.751. Also,
Adhesion between PEN film and PP film is 0.7g / c
It was m.

Next, this laminated film was put into a vacuum vapor deposition machine, and aluminum having a thickness of 0.08 μm was vapor-deposited on the surfaces of the PEN films on both sides under the conditions of a vacuum degree of 10 ⁻⁵ mmHg and a vapor deposition rate of 30 m / min. When the PEN film was peeled from this laminated film, no wrinkles were generated, and neither film breakage nor breakage occurred during peeling, and an ultrathin vapor-deposited PEN film was obtained in a clean state. In addition, P after vapor deposition
Adhesion between the layers of EN film and PP film is 0.5
It was g / cm.

When a capacitor element was manufactured in the same manner as in Example 1, the tan δ of the capacitor was 0.004.
When 0, good characteristics were shown.

Example 3 0.5% by weight of polyhydric alcohol fatty acid ester was added to glycerin monostearate in PP.
A three-layer laminated film was obtained in the same manner as in Example 1 except that the addition was changed and the thickness of the PEN film obtained by cooling and solidification was 4 μm. The process of film formation is stable,
The thickness of the obtained film was small, and a uniform three-layer film was obtained.

The thickness of the obtained laminated film was 0.3 μm for the PEN films on both outer sides and 1 for the PP film on the inner layer.
1 μm, the birefringence of the inner PP film is 0.00
It was 02. The adhesive force between the PEN film and the PP film was 0.6 g / cm.

Next, this laminated film was put into a vacuum vapor deposition machine, and aluminum having a thickness of 0.08 μm was vapor-deposited on the surfaces of the PEN films on both sides under the conditions of a vacuum degree of 10 ⁻⁵ mmHg and a vapor deposition rate of 30 m / min. When the PEN film was peeled from this laminated film, no wrinkles were generated, and neither film breakage nor breakage occurred during peeling, and an ultrathin vapor-deposited PEN film was obtained in a clean state. The adhesive force between the layers of the PEN film and the PP film was 0.4 g / cm.

Comparative Example 1 The following two types of raw materials (pellets) were prepared. (1) Polyethylene terephthalate (hereinafter sometimes referred to as "PET") pellets having an intrinsic viscosity of 0.60 and containing 0.3% by weight of a cataloid having an average particle diameter of 0.12 μm. (2) P having a melting point of 160 ° C. and containing 0.2% by weight of glycerin fatty acid ester (glycerin monostearate)
P pellets.

The PET raw material was dried at 170 ° C. for 3 hours, supplied to an extruder, and melt-extruded at 280 ° C. On the other hand, PP
The raw material was dried at 100 ° C. for 2 hours, then fed to another extruder, and melt-extruded at 280 ° C. like PET. Each melt is merged inside the die to form a PET / PP / PET three-layer laminated structure, which is then discharged from the die and wound around a cooling drum kept at 25 ° C to be cooled and solidified to form a three-layer laminated sheet. And PET layer on both outer sides is 10 μm, PP on the inner layer
The layer was 150 μm.

This sheet was heated to 90 ° C. by contacting it with a roll, and then stretched by 3.6 times in the longitudinal direction, and immediately cooled to 25 ° C. Then, it was stretched in the transverse direction by a tenter type transverse stretching device at 100 ° C. by a factor of 3.9 and then 21
After heat treatment at 0 ° C., it was cooled to room temperature and wound. The film formation was very unstable due to frequent breakage in the process, and the thickness unevenness during stretching was large.

The thickness of the obtained film is PE on both outer sides.
T film 0.7 μm, inner layer PP film 11 μm
m, and the birefringence of the PP film of the inner layer is 0.0002.
Met. The Young's modulus of the PET film in the longitudinal and transverse directions was 520 and 530 kg / mm ² , respectively.
Also, the adhesion between PET film and PP film is 0.8.
It was g / cm.

Next, this laminated film was put into a vacuum vapor deposition machine, and 0.08 μm thick aluminum was vapor deposited on the surfaces of the PET films on both sides under the conditions of a vacuum degree of 10 ⁻⁵ mmHg and a vapor deposition rate of 30 m / min.

When the PET film was peeled off from this laminated film, curls were generated largely due to its weak stiffness, which caused breakage.

[0071]

Industrial Applicability The present invention is a laminated film of a polyester film and a polyolefin film.
-Since the naphthalene dicarboxylate film is used, the breakage frequency during the stretching process is reduced and the productivity of the ultrathin film is improved. Further, since the metal is vapor-deposited in the state of the laminated film, it has become possible to supply the vapor-deposited laminated film for capacitors, which has few defects such as heat loss in the vapor deposition process.

Claims (4)

[Claims] 1. A polyolefin resin film having a birefringence of 0.01 or less has a Young's modulus of 600 kg / mm ² or more and a thickness of 0.1 at least on one side.
A vapor-deposited laminated film for capacitors, in which a polyethylene-2,6-naphthalene dicarboxylate film having a thickness of ˜2 μm is laminated with an adhesion strength of 0.1 to 2.0 g / cm, and a metal is vapor-deposited thereon. 2. The polyolefin resin film has a thickness of 5 to 5.
The vapor-deposited laminated film for capacitors according to claim 1, which is a polypropylene film having a thickness of 30 μm. 3. On both sides of the polyolefin resin film,
The vapor-deposited laminated film for capacitors according to claim 1, wherein a polyethylene-2,6-naphthalenedicarboxylate film is laminated with an adhesion strength of 0.1 to 2.0 g / cm, and a metal is vapor-deposited on the laminated film. . 4. The laminated film according to claim 1 or 3.
Peeled and removed the polyolefin resin film from the vertical,
Both Young's modulus in the lateral direction is 600 kg / mm ²Above,
Polyethylene-2,6-naphtha with a thickness of 0.1-2 μm
Metal is deposited on one side of the range carboxylate film.
Vapor-deposited laminated film for capacitors.