JP2002367847A - Manufacturing method of double-sided deposition polypropylene film, and capacitor using the film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of deposition metals adhering each other on both surfaces and releasing from each other when they are wound off in the next process when the metals are deposited on both the surfaces of a polypropylene film and are wound off as a product roll in a deposition machine. SOLUTION: In a deposition process for allowing zinc or the mixture of zinc and aluminum to be subjected to vacuum deposition onto both the surfaces of a polypropylene film being withdrawn from a master roll for winding off in a product roll, an oxidizing gas is sprayed to the side of an inner surface where the polypropylene film is wound off in contact with the product roll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a double-sided vapor-deposited polypropylene film used for a capacitor and a capacitor using the same.

[0002]

2. Description of the Related Art Capacitors made of metal-deposited plastic films (hereinafter referred to as metallized film capacitors)
Has been widely used in the past. Among them, metallized film capacitors using polypropylene film have excellent electrical properties (small dielectric loss, high withstand voltage, small changes in dielectric constant with temperature and frequency, etc.), and are representative of portable equipment. It is widely used in applications ranging from small electronic component applications to large-scale industrial applications such as train drive motor control and high-voltage lead.

FIG. 4 is a sectional view of a conventional metallized film capacitor using a polypropylene film. Two polypropylene films 42 each having a metal 41 deposited on one side are wound or laminated, and a capacitor is formed from the metallikon portion 34 where metal is sprayed from both end faces.
Aluminum, zinc, or a mixture thereof has been widely used as the vapor-deposited metal 41. However, when aluminum is used, the adhesive strength with the metallikon 34 is weak, and when a voltage is applied for a long period of time, aluminum In recent years, zinc or a mixture of zinc and aluminum is often used because of the problem that the capacity is reduced due to oxidative deterioration.

As shown in FIG. 4, the vapor deposition metal 41 is self-healing by reducing the thickness of the vapor deposition metal in the capacitor forming portion (even when the film is locally broken down, the peripheral metal deposition is not performed). The metal is evaporated and scattered to be electrically cut off, and the function as a capacitor is restored), and the heavy edge structure in which the portion in contact with the metallikon portion 34 is thickened to increase the contact strength with the metallikon portion 34 is widely used. Has been adopted.

[0005] In the conventional configuration, since two polypropylene films having a metal deposited on one side are used, a deposition step is required for each of the films, which takes a lot of man-hours. Here, if a metal is vapor-deposited on both sides of a polypropylene film in one vapor deposition step (hereinafter, a double-sided vapor-deposited polypropylene film) and a polypropylene film not deposited (hereinafter, a polypropylene film for lamination) is laminated (see FIG. 3). In addition, the deposition process can be halved.

[0006] However, when metal is deposited on both surfaces, the product rolls 3 are temporarily set in the vacuum deposition machine 1 (see FIG. 1).
(See Fig. 1)
The deposited metals on both sides come into contact with each other. Polypropylene film has low adhesion to deposited metal due to low wettability,
In addition, since the product roll is tightly wound (stress accumulated in the product roll), the vapor-deposited metals on both sides adhere to each other, and are wound from the product roll in the next process (slitting process of vapor-deposited film and winding process of capacitor). There is a problem (hereinafter, blocking) that the vapor-deposited metals on both sides are separated from each other when they are taken out. Blocking is disclosed in US Pat.
As described in Japanese Patent No. 29, it is known that the deposition metal is more remarkable when zinc is used than when aluminum is used.

When a capacitor is produced using a double-sided vapor-deposited polypropylene film in which blocking has occurred, the function as a capacitor electrode is impaired because the vapor-deposited metal on both sides peels off in the above-mentioned slitter and winding. , Tan δ (dielectric loss tangent) increases, it is indispensable to solve the blocking as a double-sided evaporated polypropylene film for a capacitor.

[0008] In view of this point, a manufacturing method for reducing blocking has conventionally been proposed. For example, U.S. Pat. No. 3,895,129 discloses a method for vapor-depositing zinc on both surfaces of a polypropylene film by blowing air on one of the vapor-deposited surfaces to oxidize the surface of the vapor-deposited metal and then winding it on a product roll. ing.

In Japanese Patent Publication No. 7-62238,
As a manufacturing method of vacuum-depositing zinc, zinc alloy or other metal on both sides of a synthetic resin film, an oxidizing gas such as air or oxygen is injected into a film winding chamber separated from a deposition chamber by a partition in a vacuum chamber. Manufacturing method is described. That is, first, a metal is vapor-deposited on one side of a polypropylene film, an oxidizing gas is sprayed on the vapor-deposited surface to oxidize the vapor-deposited film, and then the metal is vapor-deposited on the opposite surface, and then the oxidizing gas is vapor-deposited on the vapor-deposited surface. And then winding.

[0010]

However, US Pat. No. 3,895,129 and Japanese Patent Publication No. 7-62238.
In the production method disclosed in Japanese Patent Application Laid-Open Publication No. H11-157, blocking could not be solved in a double-sided vapor-deposited polypropylene film using zinc or a mixture of zinc and aluminum.

In other words, the manufacturing methods disclosed in US Pat. No. 3,895,129 and Japanese Patent Publication No. 7-62238 each blow air or an oxidizing gas onto a vapor-deposited surface of a polypropylene film running at high speed. Since the running speed of the polypropylene film in the vapor deposition step is generally 300 m to 1000 m per minute, the polypropylene film is exposed to air and oxidizing gas for a very short time of 1/100 second or less. In such a short time, in a deposited film made of zinc or a mixture of zinc and aluminum,
Since a sufficient oxide film was not formed, the blocking was not solved.

In particular, as a double-sided vapor-deposited polypropylene film for a capacitor, continuous vapor deposition is generally performed on a long polypropylene film having a length of more than 10,000 m. In the portion (close to the winding core), the stress of winding reduction is accumulated from the outside, so that blocking occurs with an insufficient oxide film. When a capacitor is manufactured using such a double-sided vapor-deposited polypropylene film, the tan δ of the capacitor increases as described above, which has been a problem.

[0013] Further, since blocking is a phenomenon caused by the adhesion between the vapor deposition films on the front and back sides, when the product is stored for a long time in the state of a product roll, blocking occurs even with an inadequate oxide film, and a capacitor is produced. Sometimes, tan δ increases, which is also a problem.

The present invention solves the above problems, and provides a good double-sided vapor-deposited polypropylene free from blocking even when zinc or a mixture of zinc and aluminum is vapor-deposited on both sides of a long polypropylene film and stored for a long period of time. The purpose is to realize a method for producing a film.
Another object of the present invention is to realize a good capacitor with low man-hours and no increase in tan δ due to blocking by using the double-sided vapor-deposited polypropylene film.

[0015]

In order to achieve the above object, a method for producing a double-sided vapor-deposited polypropylene film according to the first aspect of the present invention is a method for producing a double-sided vapor-deposited polypropylene film. A production method comprising a vapor deposition step of vacuum-depositing a mixture and winding the mixture onto a product roll, wherein an oxidizing gas is sprayed on an inner surface side where the polypropylene film is wound in contact with the product roll.

According to a second aspect of the present invention, there is provided a method for producing a double-sided vapor-deposited polypropylene film according to the first aspect of the present invention, further comprising a blow-off portion for blowing an oxidizing gas. This is a manufacturing method of following and moving according to the radius of the product roll that increases.

The method for producing a double-sided vapor-deposited polypropylene film according to claim 3 is the method for producing a double-sided vapor-deposited polypropylene film according to claim 1 or 2, wherein oxygen is used as an oxidizing gas.

According to a fourth aspect of the present invention, there is provided a method for producing a double-sided vapor-deposited polypropylene film according to any one of the first to third aspects. But 34 to 41 dyn / c on both sides
m.

A method for producing a double-sided vapor-deposited polypropylene film according to a fifth aspect of the present invention is the method for producing a double-sided vapor-deposited polypropylene film according to any one of the first to fourth aspects of the present invention. Has a maximum surface roughness (hereinafter referred to as Rmax) of 1.0 to 2.0 μm and an average surface roughness (hereinafter referred to as Ra) of 0.1 μm or more.

[0020] The method for producing a double-sided vapor-deposited polypropylene film according to claim 6 is the method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 5 of the present invention. Is a production method in which the isotacticity is 96% or more.

A capacitor according to a seventh aspect of the present invention includes the double-sided vapor-deposited polypropylene film according to any one of the first to sixth aspects and a matching polypropylene film.

[0022]

According to the method for producing a double-sided vapor-deposited polypropylene film according to the first aspect of the present invention, zinc or a mixture of zinc and aluminum is vacuum-deposited on both sides of a polypropylene film drawn from a raw roll. By providing a vapor deposition step of winding the product roll, the oxidizing gas is sprayed on the inner surface side where the polypropylene film is wound in contact with the product roll, so that the oxidizing gas is caught inside the product roll. Since the oxidation reaction of the deposited film proceeds even after being wound up on the product roll, a sufficient oxide film is formed. Therefore, even when continuous vapor deposition is performed on a long polypropylene film, a double-sided vapor-deposited polypropylene film having no blocking can be produced.

According to the method for producing a double-sided vapor-deposited polypropylene film according to the second aspect, in the method for producing a double-sided vapor-deposited polypropylene film according to the first aspect, the number of blow-out portions for blowing an oxidizing gas is increased during the vapor deposition step. By following the product roll in accordance with the radius of the product roll,
Since the oxidizing gas can be sprayed at a constant distance until the end of the vapor deposition where the radius increases, a uniform double-side vapor-deposited polypropylene film can be produced even in the continuous vapor deposition process of a long film.

According to the method for producing a double-sided vapor-deposited polypropylene film according to the third aspect, in the method for producing a double-sided vapor-deposited polypropylene film according to the first aspect, an oxygen gas is used as the oxidizing gas. Is formed, and a double-sided vapor-deposited polypropylene film having no blocking can be produced.

According to a method for producing a double-sided vapor-deposited polypropylene film according to claim 4, in the method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 3, The surface wetting index is 34-41 on both sides
Since it is dyn / cm, it is possible to produce a good double-sided vapor-deposited polypropylene film which is excellent in adhesion between the vapor-deposited metal and the polypropylene film and in which the polypropylene films are not adhered to each other in the above-mentioned raw roll. That is, when the surface wetting index of the polypropylene film is less than 34 dyn / cm, the adhesion between the vapor-deposited film and the polypropylene film is poor, so that the vapor-deposited film is easily peeled off, and blocking is liable to occur. Further, if it exceeds 41 dyn / cm, the polypropylene films adhere to each other in the raw roll,
Unable to unwind smoothly from the raw roll.

According to a method for producing a double-sided vapor-deposited polypropylene film according to claim 5, in the method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 4, The surface roughness of at least one side is Rma
x is 1.0 to 2.0 μm, and Ra is 0.1 μm
By performing the above, a double-sided vapor-deposited polypropylene film which is excellent in workability without wrinkles or meandering in the next step of slitting or winding can be produced.
Since the metal is vapor-deposited on both sides of the double-sided vapor-deposited polypropylene film, if the surface roughness falls below this range, a slitter (not shown) for cutting the double-sided vapor-deposited polypropylene film to a predetermined width, or a roll-up machine. Smooth running cannot be obtained between the rollers provided in a large number of removing machines (not shown) and the double-sided vapor-deposited polypropylene film, and wrinkles or meanders occur. In addition, Rmax is 2.0 μm
If Rmax is more than 2.0, the thickness of the polypropylene film becomes non-uniform, and when a capacitor is manufactured and a voltage is applied, the polypropylene film is easily broken at the thinnest portion. Therefore, Rmax is preferably 2.0 μm or less.

According to the method for producing a double-sided vapor-deposited polypropylene film according to claim 6, in the method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 5, By setting the isotacticity to 96% or more, the stereoregularity of the crystals of the polypropylene film is improved, so that the elastic modulus of the polypropylene film is improved, and the above-mentioned product roll winding reduction can be reduced. Therefore, when the product is to be stored or transported for a long time in the state of a product roll, it is possible to reduce squeezing even if the ambient temperature rises, thereby producing a double-sided evaporated polypropylene film having excellent long-term storage and transportability. can do. The isotacticity is a ratio of the isotactic three-dimensional structure to the whole in the polypropylene film, and can be measured by ¹³ C-NMR as an index indicating the degree of stereoregularity of the polypropylene film.

According to the capacitor of the seventh aspect,
Since it comprises a double-sided vapor-deposited polypropylene film and a matching polypropylene film according to any one of claims 1 to 6, the vapor-deposition step takes only one time,
In addition, since the dielectric is entirely a polypropylene film, a low-cost capacitor having good electrical characteristics can be realized.

(Embodiment 1) The present embodiment will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing a method for producing a double-sided vapor-deposited polypropylene film, and FIG. 2 is an enlarged explanatory view showing the vicinity of a product roll in FIG.

In the figure, a polypropylene film 4 is unwound from a raw roll 2 attached to the inside of a vapor deposition machine 1, and a primary cooling can 5 a is provided with a primary aluminum evaporation source 6 a and a zinc evaporation source 7 a. Is formed on one side of the polypropylene film 4, and then the secondary side evaporation can 6b and the zinc evaporation source 7b are deposited on the opposite side of the polypropylene film 4 in the secondary side cooling can 5b. Form metal. In addition, the gas and moisture adsorbed on the polypropylene film 4 in the raw fabric roll 2 are removed by the evaporation source 5.
This is conventionally provided for partitioning so as not to deteriorate the degree of vacuum in the vicinity of a, 5b, 6a and 6b.

Next, when the polypropylene film 4 vapor-deposited on both sides is wound on the product roll 3 via the roller 11 provided in the follow-up drive unit 8, the blowing port 9 provided in the follow-up drive unit 8 is used. The oxidizing gas 10 is blown to the inner surface side where the polypropylene film 4 is wound in contact with the product roll 3. The following drive unit 8
2 is a mechanism that drives the pinion gear 13 to follow the radius of the product roll 3 that increases during the vapor deposition process and rotates about the rotation shaft 12 as shown in an enlarged view in FIG. By keeping the distance between the roll 11 disposed above and the product roll 3 constant, the polypropylene film 4 can be evenly wound around the product roll 3 even in long continuous vapor deposition.

The oxidizing gas 10 has its flow rate adjusted by, for example, a flow valve 15 and is blown from a blowout port 9 through a pipe 14. Since the sprayed oxidizing gas 10 is caught in the inside of the product roll 3, the vapor deposition surfaces on both sides of the polypropylene film 4 are exposed to the oxidizing gas 10 for a long time to form an oxide film, thereby preventing blocking. it can.

The mounting position of the blow-out port 9 is not particularly limited as long as the oxidizing gas 10 can be blown onto the inner surface side. For example, the vapor-deposited film is continuously vapor-deposited on a long polypropylene film 4 having a length exceeding 10,000 m. In such a case, it is desirable to install on the following drive unit 8. That is, even if the radius of the product roll 3 increases during the vapor deposition process, the distance and the angle are kept constant and the oxidizing gas 10 is maintained.
Is sprayed, so that a uniform effect over a long length can be obtained.

FIG. 3 shows a cross-sectional view of a double-sided vapor-deposited polypropylene film capacitor, which is a double-sided vapor-deposited polypropylene film 32 composed of a polypropylene film 4 and a vapor-deposited metal 31 formed on the surface thereof, and a matching polypropylene film 33. And a deposition electrode 31
The electrode is taken out by the metallikon 34 attached to.

As described above, since the double-sided vapor deposition is performed, only one vapor deposition step is required, and the oxidizing gas 10 is sprayed on the inner surface side where the polypropylene film 4 comes into contact with the product roll 3 and is wound. tan
An inexpensive capacitor having good electrical characteristics without an increase in δ can be realized.

Next, the blocking of the double-sided vapor-deposited polypropylene film 32 manufactured according to the first embodiment will be described in comparison with the prior art.

In the present embodiment, the thickness is 4 μm, the surface wetting index is 37 dyn / cm on both sides, the surface roughness is Rmax = 1.6 μm, Ra = 0.2 μm, and the isotacticity is 96%. Using the polypropylene film 4 having a length of 15000 m, the following double-sided vapor-deposited polypropylene film 32 was produced.

Embodiment 1-1: Zinc was vapor-deposited on both sides of a polypropylene film 4 and was wound around a product roll 3 by blowing oxygen by the method shown in FIG.

Embodiment 1-2: A mixture of zinc and aluminum was vapor-deposited on both sides of a polypropylene film 4 and air was blown by the method shown in FIG.

Embodiment 1-3: A mixture of zinc and aluminum was vapor-deposited on both sides of a polypropylene film 4 and was wound around a product roll 3 by blowing oxygen by the method shown in FIG.

Next, after the product roll 3 is taken out from the vapor deposition machine, sampling is performed while unwinding the double-sided vapor-deposited polypropylene film 32 at the outermost and innermost peripheral portions of the product roll 3, and the peeling state of the vapor-deposited metal 31. Was observed with a transmission microscope at 50 × and photographed. The photograph was digitally processed with a personal computer, and the portion where the vapor deposition metal 31 was peeled off was binarized into a portion where the vapor deposition metal 31 was not peeled off. For comparison, the peeling ratio was also determined for the following samples as a double-sided vapor-deposited polypropylene film of the prior art.

Prior art 1-1: Zinc was vapor-deposited on both surfaces of the polypropylene film 4 and wound up on the product roll 3 as it was.

Prior art 1-2: A mixture of zinc and aluminum is vapor-deposited on both surfaces of a polypropylene film 4 and air is blown by a method shown in FIG. 1 of Japanese Patent Publication No. 7-62238 and wound on a product roll 3. Was.

Prior art 1-3: A mixture of zinc and aluminum is vapor-deposited on both sides of a polypropylene film 4 and is blown with oxygen by the method shown in FIG. Was.

Table 1 shows the rate at which the deposited metal was peeled off from each sample. In the present embodiment, the rate at which the deposited metal peeled off is extremely small even in the inner peripheral portion of the product roll 3 where the stress is accumulated, and it can be seen that a good double-sided deposited polypropylene film that cannot be obtained by the conventional technique can be manufactured.

[0047]

[Table 1]

Next, as a characteristic example of the capacitor according to the present embodiment, the double-sided vapor-deposited polypropylene film 32 and the matching polypropylene film 33 produced in the first embodiment are wound to produce the capacitor (10 μF) shown in FIG. Tan δ at 1 kHz was measured.

In each of the capacitors, the innermost peripheral portion of the product roll 3 was used as the double-sided vapor-deposited polypropylene film 32.

The results obtained are shown in (Table 2). While the capacitor according to the prior art increases the tan δ due to the increase in the series equivalent resistance due to the separation of the electrodes, the capacitor according to the present embodiment has a low tan δ and exhibits good characteristics.

[0051]

[Table 2]

Next, in order to examine the influence of the surface wetting index of the polypropylene film 4, first, the corona treatment strength of the polypropylene film 4 was changed to produce polypropylene films 4 having different surface wetting indices. Was vapor-deposited, and oxygen was sprayed by the method shown in FIG. 1 to produce a double-sided vapor-deposited polypropylene film 32. The thickness of the polypropylene film 4 used was 6 μm, the length was 2000 m, the surface roughness was Rmax = 1.3 μm, Ra = 0.15 μm, and the isotacticity was 97%. The rate at which the deposited film was peeled off and the finish of the product roll 3 were examined. The obtained results are shown in (Table 3).

[0053]

[Table 3]

When the surface wetting index of the polypropylene film 4 is less than 34 dyn / cm, the vapor deposition metal 31
Since the adhesion between the film and the polypropylene film 4 was reduced, the rate of peeling of the deposited film was increased to 0.8%. If the wetting index exceeds 41 dyn / cm, the polypropylene films 4 adhere to each other on the raw material roll 2 and cannot be smoothly unwound, so that the product roll 3 is wrinkled or the film breaks. I did it.

When the wetting index on both sides of the polypropylene film 4 was in the range of 34 to 41 dyn / cm, a double-sided vapor-deposited polypropylene film 32 having no blocking and a good finish of the product roll 3 could be obtained.

Next, in order to examine the influence of the surface roughness of the polypropylene film 4, a polypropylene film 4 having a different surface roughness was prepared, and aluminum and zinc were vapor-deposited on both surfaces thereof. By spraying oxygen, a double-sided evaporated polypropylene film 32 was produced. Further, this double-sided vapor-deposited polypropylene film 32 was cut by a slitter, and the degree of wrinkling during the slitter was examined. The results are shown in (Table 4). The primary side and the secondary side indicate each surface of the polypropylene film 32.

[0057]

[Table 4]

The surface roughness of the polypropylene film 4 is
When Rmax was 1 μm or more and Ra was 0.1 μm or more, no wrinkles occurred during winding of the capacitor.

Further, in order to examine the influence of the stereoregularity of the polypropylene film 4, polypropylene films 4 having different isotacticity were prepared, and aluminum and zinc were vapor-deposited on both surfaces thereof. By exposing to oxygen gas, a product roll 3 of a double-sided vapor-deposited polypropylene film 32 was prepared and
It was left at 0 ° C., and the result of examining the size of the blocking is shown in (Table 5).

[0060]

[Table 5]

When the isotacticity of the polypropylene film 4 is 95%, since the heat shrinkage of the double-sided vapor-deposited polypropylene film 32 progresses while the polypropylene film 4 is left at 40 ° C. for 60 days, the product roll 3 gradually tightens. Blocking in which the metals 31 were adhered to each other and peeled off was observed, but when the isotacticity was 96% or more,
Since the stereoregularity of the polypropylene film 4 is increased and heat shrinkage is unlikely to occur, no blocking is recognized. Therefore, even when the product roll 3 is stored for a long time, blocking does not occur. A polypropylene film 32 can be manufactured.

In this embodiment, the polypropylene film 4 having a thickness of 4 μm and 6 μm is used, but the same effect can be obtained with other thicknesses.

Although the embodiment of the present invention is shown in FIGS. 1 and 2, the present embodiment is not limited to these, and the both sides of the polypropylene film 4 drawn out from the raw roll 2 can be used. In a vapor deposition step of vacuum-depositing zinc or a mixture of zinc and aluminum and winding the product roll 3 on a product roll 3, a method in which the oxidizing gas 10 is sprayed on the inner surface side where the polypropylene film 4 is in contact with and wound on the product roll 3. The same effect can be obtained.

Although examples of oxygen and air have been given as examples of the oxidizing gas 10, the present invention is not limited to these, and the same effect can be obtained if the gas has an oxidizing property. it can.

[0065]

As described above, according to the method for producing a double-sided vapor-deposited polypropylene film according to the first to third aspects of the present invention, zinc or zinc and aluminum are applied to both sides of the polypropylene film drawn from the raw roll. In a vapor deposition step of vacuum-depositing the mixture of the above and winding the product roll on a product roll, the oxidizing gas is caught inside the product roll by spraying the oxidizing gas on the inner surface side where the polypropylene film is wound in contact with the product roll. Therefore, even when continuous vapor deposition is performed on a long polypropylene film, a double-sided vapor-deposited polypropylene film having no blocking can be produced.

According to the method for producing a double-sided vapor-deposited polypropylene film according to claim 4, in the method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 3, The surface wetting index is 34-41 on both sides
Since it is dyn / cm, a product roll of a good double-sided vapor-deposited polypropylene film without wrinkles or meandering can be produced.

According to the method for producing a double-sided vapor-deposited polypropylene film according to the fifth aspect of the present invention, in the method for producing a double-sided vapor-deposited polypropylene film according to any one of the first to fourth aspects, The surface roughness of at least one side is Rma
x is 1.0 to 2.0 μm, and Ra is 0.1 μm
By performing the above, a double-sided vapor-deposited polypropylene film which is excellent in workability without wrinkles or meandering even in the next step of slitting or winding can be produced.

According to a method for producing a double-sided vapor-deposited polypropylene film according to claim 6, in the method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 5, By setting the isotacticity to 96% or more, a double-sided vapor-deposited polypropylene film excellent in long-term storage and transportability can be produced.

According to the capacitor of the seventh aspect,
Since it comprises a double-sided vapor-deposited polypropylene film and a matching polypropylene film according to any one of claims 1 to 6, the vapor-deposition step takes only one time,
In addition, since the dielectric is entirely a polypropylene film, a low-cost capacitor having good electrical characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for producing a double-sided vapor-deposited polypropylene film according to Embodiment 1 of the present invention.

FIG. 2 is an enlarged view of the vicinity of a product roll according to the first embodiment.

FIG. 3 is a cross-sectional view of a double-sided vapor-deposited polypropylene film capacitor according to the first embodiment.

FIG. 4 is a sectional view of a conventional capacitor.

[Description of Signs] 1 Vacuum evaporation machine 2 Raw material roll 3 Product roll 4 Polypropylene film 5a, 5b Cooling can 6a, 6a Aluminum evaporation source 7a, 7b Zinc evaporation source 8 Follow-up moving part 9 Blow-out port 10 Oxidizing gas 11 Roller 12 Rotating shaft 13 Pinion gear 14 Oxidizing gas pipe 15 Flow valve 16 Partition wall 31 Deposited metal 32 Polypropylene film 33 Polypropylene film for alignment 34 Metallicon

Continued on the front page (72) Inventor Kazumi Namura 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroki Takeoka 1006 Odaka Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Kazuhiro Nakatsubo 1006 Kadoma, Kazumasa, Kadoma, Osaka Pref., Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshiyuki Nishimori 1006, Kadoma, Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshihiro Sasaki 1006 Ojimon Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. (72) Inventor Shigeo Okabe 1006 Kadoma Kadoma, Kadoma, Osaka Matsushita Electric Industrial Co., Ltd. F term (reference) 4K029 AA11 AA25 BA03 BA18 BA21 BA23 BB04 BD00 CA01 DB14 GA00 5E082 FG06 FG34 FG42

Claims (7)

[Claims] 1. A vapor deposition step in which zinc or a mixture of zinc and aluminum is vacuum-deposited on both surfaces of a polypropylene film drawn from a raw roll and wound up on a product roll, wherein the polypropylene film is wound on a product roll. A method for producing a double-sided vapor-deposited polypropylene film, characterized by spraying an oxidizing gas onto the inner surface of the polypropylene film. 2. The method for producing a double-sided vapor-deposited polypropylene film according to claim 1, further comprising a blow-out portion for blowing an oxidizing gas, wherein the blow-out portion is moved in accordance with a radius of a product roll which increases during a vapor deposition process. . 3. The method according to claim 1, wherein oxygen is used as the oxidizing gas.
Or the method for producing a double-sided vapor-deposited polypropylene film according to 2. 4. A polypropylene film drawn from a raw roll has a surface wetting index of 34 to 41 d on both sides.
The method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 3, which is yn / cm. 5. The surface roughness of at least one side of the polypropylene film drawn from the raw roll is such that the maximum surface roughness is 1.0 to 2.0 μm and the average surface roughness is 0.1 μm or more. A method for producing a double-sided vapor-deposited polypropylene film according to any one of claims 1 to 4. 6. The method for producing a double-sided vapor-deposited polypropylene film according to claim 1, wherein the polypropylene film drawn from the raw roll has an isotacticity of 96% or more. 7. A capacitor comprising the double-sided vapor-deposited polypropylene film according to claim 1 and a matching polypropylene film.