JP2008100327A - Film punching method and punched film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film punching method for punching a film to be punched having a small initial tensile stress (at the time of 1%-elongation) so as to have pores of predetermined shapes continuously without distortion. <P>SOLUTION: According to the film punching method, a laminated film is obtained by laminating a carrier film on the film to be punched via a water-easily-soluble adhesive layer, to reinforce the film so as to have a breaking stress of 80 N/15 mm width or more, a breaking elongation of 155% or less, and the initial tensile stress (at the time of 1%-elongation) of 8 N/15 mm width or more. Then the laminated film thus reinforced is punched, and thereafter the carrier film layer is separated and removed. Herein the separation and removal is preferably carried out by water submersion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for perforating a film and a perforated film, and more specifically, even when the initial tensile stress of the perforated film is small, the perforation position is not shifted and the perforating method is stable. The present invention relates to a laminated film and a perforated film used in the method.

In general, most of plastic films are transparent, water and solvent resistant, and block the permeation of air and liquid, so they are useful as various packaging materials and structural materials. However, depending on the application, water resistance and solvent resistance may be required, but liquid permeability and air permeability may be required. For example, agricultural house films, separator films used inside fuel cells, ions For applications such as base materials and core materials such as exchange membranes, it is used as a perforated film obtained by appropriately perforating a water-resistant or solvent-resistant plastic film.

  Among the above-mentioned typical perforated films (hereinafter abbreviated as perforated films), in the case of house films, generally inexpensive polyethylene and polypropylene films are used, and the thickness is large and the structural strength is large. In addition, since a high drilling accuracy is not always required, the drilling method can be practically used, for example, as long as the required hole diameter is formed substantially evenly. A method in which pressure is perforated while running a transparent synthetic resin film selected in advance on a needle roll on which a forming needle for piercing a required air hole is formed with a predetermined interval, and a predetermined interval is set. Accordingly, it is disclosed that a mass production method such as a method of forming a hole by bringing it into contact with a holed pin installation roll in which a heated hole forming pin is implanted can be applied. (Patent Document 1)

  In the case of the separator film and core material used inside the fuel cell, the position and shape of the perforations greatly affect the characteristics of the fuel cell. In order to further improve the performance as a battery, the separator A film or the like that is as thin as possible is required. As a typical example, fine holes having a diameter of 0.1 to 0.5 mm are tightly perforated on the entire surface of a thin PPS film having a thickness of 10 to 20 μm, for example. In such a case, as a method for perforating a large number of holes in a film, for example, a laser method, a drill method, a press method using a concavo-convex mold blade, and the like are known. As a method for perforating, a concavo-convex gold, which is a combination of a convex blade in which thin round bar-shaped convex blades having a cross-section in the shape of a hole are arranged at a perforation position and a round hole-shaped concave blade placed on the back of the perforating film, is used. Although a press type using a mold blade is suitably applied, it takes time and cost to manufacture such a complicated and highly accurate concavo-convex mold blade. A press machine having a die blade may be used to perform drilling in a predetermined arrangement while moving the blade position.

  In that case, when the film for punching is thin and therefore the initial tensile stress is small, pulling wrinkles are likely to occur at the time of handling. When the sheet is stretched by the tension applied to the film and the film surface is waved, or the sheet is passed with a weak tension to avoid this, the perforating film swings in the width direction. In particular, when a pair of concave and convex mold blades is used to move the mold blade position in the width direction and the length direction of the film and perforate to a specified position, such a thin perforated film is waved as described above. Because it hits and swings in the width direction, the drilling position does not become a predetermined position and it has no commercial value at all. When pulling up the convex blade, a thin plastic film is pulled by the convex blade and lifts up and moves up and down, so that the perforation operation cannot be continued smoothly. As a method of avoiding such behavior, a method of concealing defects due to this thinness only at the time of drilling by laminating a carrier film etc. on the back of a thin plastic film to reinforce the thickness and tensile stress, and a method of peeling after drilling is conceived. The

The carrier film is attached to the back surface of the perforating film via an adhesive layer to reinforce it. In this case, when the carrier film is peeled and removed after the perforation, the perforation film is thin, and therefore, wrinkles are easily generated due to the tensile stress at the time of peeling. This can be avoided to some extent by adjusting the peel strength (lightness at the time of peeling) of the pressure-sensitive adhesive layer of the carrier film to a low level depending on the thickness of the perforated film.

However, the adhesive of the carrier film tends to protrude inside the hole during perforation or part of the adhesive residue on the back surface of the perforated film when peeled after perforation. Is generally an adhesive such as acrylic, urethane, or silicone, and remains, for example, as an impurity in a fuel cell as a precision instrument. The above-mentioned pressure-sensitive adhesive is usually water-insoluble and cannot be dissolved and removed with an aqueous solvent, and even if it is water-soluble, it is not easily dissolved in an aqueous solvent and is dissolved under hot water conditions or immersed for a long time. It was necessary and not practical.
Japanese Patent Laid-Open No. 10-210870

    From the above point of view, the present inventors use a water-soluble adhesive layer that does not apply tensile stress to the perforating film as a laminating adhesive between the perforating film and the carrier film. The inventors have come up with a method for easily isolating the perforated film by immersing the perforated laminated film in water. However, when a general-purpose polyester film having a thickness of 38 mm, for example, is used as the carrier film, the carrier film cannot be completely cut during perforation, and the laminated film is pulled by the convex blade that moves up and down of the perforation apparatus. It has been found that there is a problem that the film perforation position is not stable due to the rocking motion, and is sometimes continuous with the already perforated holes, resulting in cutting. In particular, this effect is significant when the perforation diameter is 1 mm or less, strictly 500 μm or less and the distance between the holes is short.

The present invention solves the above-mentioned difficulties, and when perforating a perforated film, even if the initial tensile stress is small, such as when the film is thin, the perforation position is not displaced and the process is stable. A perforating method and a laminated film for use in the perforating method are provided.

The first gist of the present invention is that when a perforated film having a small initial tensile (at 1% elongation) stress is continuously perforated in a state where the film is passed through the process, a carrier film is interposed via a water-soluble adhesive layer. After perforating in the state of a laminated film reinforced so that the breaking stress is 80 N / 15 mm width or more, the breaking elongation is 155% or less, and the initial tensile (at 1% elongation) stress is 8 N / 15 mm width or more. A method for perforating a film having a small initial tensile (at the time of 1% elongation) characterized by peeling and removing the carrier film layer.
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The second gist of the present invention is that a carrier film is laminated on a perforating film having a small initial tensile (at 1% elongation) stress through an easily water-soluble adhesive layer, and the breaking stress is 80 N / 15 mm width. As described above, the laminated film reinforced so that the breaking elongation is 155% or less and the initial tensile (at 1% elongation) stress is 8 N / 15 mm width or more.
It is in.

And the third gist of the present invention is that when the micro-perforations are arranged and perforated in the continuous process on the perforating film having a small initial tensile (at 1% elongation) stress, the carrier is interposed via the easily water-soluble adhesive layer. The film was laminated and punched in the state of a laminated film reinforced so that the breaking stress was 80 N / 15 mm width or more, the breaking elongation was 155% or less, and the initial tensile (at 1% elongation) stress was 8 N / 15 mm width or more. Later, it is in a perforated film obtained by peeling off the carrier film layer.

  In the present invention, when a perforated film having a low initial tensile stress (when stretched by 1%) is continuously perforated in a state where the paper is passed through the process, the carrier film is laminated via a water-soluble adhesive layer to break. By punching in the state of a laminated film reinforced so that the stress is 80 N / 15 mm width or more, the breaking elongation is 155% or less, and the initial tensile (at 1% elongation) stress is 8 N / 15 mm width or more, the drilling position is A perforated film that can be stably continued and is free from distortion in the perforated shape can be obtained by immersion and washing in an aqueous solvent after perforation.

In the perforating method of the present invention, perforation is performed in the state of a laminated film obtained by laminating a carrier film on a perforating film.

The material for the above-mentioned perforating film is not particularly limited as long as it can be perforated by a perforation method described later. For example, polyolefin resin such as polyethylene and polypropylene; polyethylene terephthalate, polybutylene terephthalate, Polyester resins such as polyethylene naphthalate; Polyamide resins such as 6-nylon, 6-6 nylon and 6-12 nylon; Polyurethane resins; Polyacrylic resins; Fluorine resins; Silicone resins; Polyimide resins; Resin: Rubber resin; Vinyl chloride resin; Other resins or those usually used as plastic films produced by blending these resins can be applied, and paper, cellophane, etc. are generally inferior in water resistance. Tosa That also include those subjected to water-resistant treatment of the extent of withstanding the aqueous solvent immersion even material.

Although the thickness of the perforating film itself is not particularly limited, an initial tensile stress (at the time of 1% elongation) that usually causes wrinkles or undulations in the perforating process described later is used when the thickness is thin. Small, for example, 8N / 15mm width or less, and more prominent examples are 4N / 15mm width or less, and breakage that may occur after perforation, for example
There is a remarkable effect in the case of a film having a stress of 80 N / 15 mm width or less, particularly a film having a low breaking strength of 100 N / 15 mm width or less when the perforated area density is high. The thickness varies depending on the material constituting the perforated film, but is generally 40 μm or less, further 30 μm or less, and may be 20 μm or less depending on the material.

The carrier film is a film laminated to reinforce the perforated film, and has a breaking stress of not less than 80 N / 15 mm width and a breaking elongation of not more than 155% through an easily water-soluble adhesive described later. Tensile (at 1% elongation) stress
It is reinforced so that the width is 8 N / 15 mm or more. Particularly, when perforation is performed densely, a film for perforation having a breaking stress of less than 100 N / 15 mm width and a breaking elongation of 155% or more is continuously and densely formed. A carrier film is laminated through an easily water-soluble adhesive layer when perforating the material, and the breaking stress is 100 N / 15 mm width or more, the breaking elongation is 155% or less, and the initial tensile (at 1% elongation) stress is 16 N / It is laminated so as to have a width of 15 mm or more.

The case where the above perforations are densely performed means that, for example, when the perforations are arranged, the substantial width of the film remaining portion in the width direction of the film is 30% or less, particularly 20% or less of the original film width. The film tension in the process is substantially supported by a portion of 30% or less and 20% or less, and is in a so-called stress concentration state, so that it receives a tension that cannot be predicted in a normal paper passing process. . Incidentally, in the case of the embodiment of the present invention, since the holes having a diameter of 300 μmφ are arranged at a pitch of 350 μm in the width direction, the substantial width of the remaining film portion is about 14%.

When the initial tensile stress (at 1% elongation) after laminating the carrier film is less than 8 N / 15 mm width, pulling wrinkles are likely to occur when the laminate is passed through the perforating process, and the perforated shape is the desired shape. It is easy to become distorted by coming off. If the tension of the paper is weakened to avoid the occurrence of pulling wrinkles, the film will wave and swing and the perforation position will become unstable, making it impossible to arrange them at regular intervals. In extreme cases, adjacent holes will overlap. Or cause cutting of the film. In particular, when perforation is performed densely, the initial tensile (at 1% elongation) stress is preferably 16 N / 15 mm width or more.
Further, when the breaking stress of the laminate is less than 80 N / 15 mm width, the film is tensioned to the extent that the film does not swing in the paper passing state.
When it does, it will become easy to produce a cut | disconnection in the continuous part which remain | survives after a drilling, and when a drilling is performed densely, it is preferable that a breaking stress is 100 N / 15mm width or more.
In addition, when the elongation at break is 155% or more, the laminate is difficult to cut completely at the stage of drilling operation, and a drag phenomenon due to the uncut portion tends to occur. In this case, the laminated film moves up and down the punching blade. The position for drilling is displaced and sometimes causes cutting.

As a material constituting such a carrier film, a copper foil, a hard aluminum foil, a stainless steel, as well as those which have shown the material characteristics as a carrier film by increasing the thickness of the films listed as the above-mentioned perforating film Metal foils such as steel foil, and those obtained by laminating a plurality of types of the above films and metal foils can be used. Among them, a copper foil having a high breaking stress and a low breaking elongation is very preferable from the viewpoint of characteristics alone. In addition, since the carrier film is a secondary material to the last, a material that is inexpensive and easy to handle is more preferable.For example, the inorganic film such as silica fine particles and calcium carbonate particles are added, and the elongation at break of the laminated film after reinforcement with the carrier film A polyester resin film satisfying about 155% or less is also practical.

The upper limit of the thickness of the carrier film is not particularly limited as long as it has a piercing property, but is preferably not more than twice the diameter of the hole from the viewpoint of balance with the diameter of the hole to be punched. Further, from the viewpoint of cost and the like, it is usually 500 μm or less, and may be 100 μm or less as long as it exhibits the above characteristics, and practically 50 μm or less is sufficient.

The adhesive used for laminating the carrier film on the above-mentioned perforated film has an adhesive property that does not peel in the perforating process and is easily pulled after perforation, that is, the perforated film and the carrier film are pulled. An adhesive that can be peeled off by a tensile stress that does not cause wrinkles is preferable. For example, it is possible to obtain a solubility that can be separated from water by being wet or dissolved by immersing the adhesive layer of the laminated film in an aqueous solvent. What can be used, that is, an easily water-soluble adhesive is preferably used. The easily water-soluble adhesive used in the present invention means an adhesive that dissolves easily in water or an aqueous solvent.

Specifically, the water-soluble adhesive is appropriately selected from known adhesives depending on the type of material constituting the target perforating film and carrier film. Specific examples of commercially available agents include water-soluble urethane resin-based "Paramilion AF-36" and "Paramilion FL-34" (both trade names, manufactured by Ohara Palladium Co., Ltd.). Yes, but not limited to these.

The aqueous solvent includes all solvents that are normally recognized as aqueous solvents in addition to water. For example, a water-soluble organic solvent such as methanol, ethanol, propanol, or glycols is added to 100 parts by mass of water. The mixed solvent which mix | blended 100 mass parts or less can be mentioned. Moreover, although it is desirable that the temperature of the solvent at the time of immersion is normal temperature, for example, the temperature may be 45 ° C. or lower.

The method for laminating the perforating film and the carrier film to form a laminated film can be performed by a known means. For example, when a heat-adhesive adhesive such as the above-mentioned Paramilion AF-36 is used as the adhesive, the carrier film is usually bonded to avoid excessive tensile stress on the thin perforated film. Apply the adhesive solution to the surface to be dried and dry it to obtain a carrier film having an adhesive layer. The surface of the carrier film having the adhesive layer is superposed on the surface to be bonded of the perforated film and heated. A method of laminating is exemplified. In the above laminating step, it is preferable that tension is not applied to the perforated film as much as possible. For example, when a long product is continuously manufactured, consideration is given to using a device such as a tension cutter together. It is preferable to

The concentration of the adhesive solution is appropriately set according to the type and characteristics of each adhesive, but is usually 2 to 50% by mass, but the applied amount of the adhesive is the thickness after drying, Usually, 0.1 to 5 μm, practically about 0.2 to 1 μm, which may be relatively small, the concentration of the adhesive solution may be 2 to 10% by mass. Moreover, although drying conditions are suitably set by the kind of adhesive used, the density | concentration of a solution, the application quantity, etc., it is about 30 to 180 second normally in a hot air of 80-100 degreeC.

  The laminated film having the structure of the perforated film layer / adhesive layer / carrier film layer obtained as described above is reinforced with the tensile stress even if the initial tensile stress of the perforated film itself is low. Therefore, it is a laminated film suitable for the perforating process, and the perforating process is stabilized by perforating in the state of this laminated film, and the accuracy of the perforating position is excellent.

  The means for perforating the laminated film is not particularly limited, and known means can be applied. For example, a tip-shaped convex shape corresponding to the target perforated shape and a concave shape corresponding thereto And press-type perforation with a concave and convex mold blade arranged in a desired pattern. In particular, a punching device of a type in which a punching position is appropriately controlled by a control mechanism using a pair of concave and convex mold blades can be suitably used.

  From the laminated film perforated by the above means, the target perforated film is isolated by removing and / or peeling the laminated adhesive layer and carrier film layer. At this time, particularly when there are portions where the perforations of the film are dense, and there are no portions where the area ratio of the non-perforated portions is large in the running direction of the film, the wrinkles are easily generated by a slight tensile stress. Therefore, it is preferable to handle the perforated laminated film carefully so as not to be subjected to tensile stress as much as possible.

The method for removing and / or peeling the adhesive layer and carrier film layer of the laminated film perforated by the above means is to swell the adhesive layer by applying an aqueous solvent to the adhesive layer of the perforated laminated film. Alternatively, there can be mentioned a method of dissolving or removing in a state where a strong tensile stress is not applied to the perforated film. As a specific example of such a method, for example, after forming a peeling opening at the end of the perforated laminated film, it is immersed in a bath of an aqueous solvent at room temperature, and is peeled off while maintaining the peeling opening in the aqueous solvent. The method of taking out from the bath of a solvent can be mentioned. The speed of taking out from the water bath is appropriately adjusted depending on conditions such as the water solubility of the adhesive used and the degree of perforation. The perforated film thus isolated can be washed by rinsing and rinsing the remaining adhesive, if necessary, in the above-mentioned aqueous solvent bath or its flow, if necessary in a warm bath or its flow. A perforated film having a uniform perforation pitch and no residue of an adhesive or the like can be easily obtained.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.
In the examples and comparative examples, the evaluation methods for various characteristics were based on the following criteria.

(1)
Film properties for perforation (initial tensile stress)
Using a Tensilon tensile tester as a measuring device, test piece width: 15 mm, distance between chucks: 150 mm, pulling speed: 200 mm / min, tensile test: 3 test pieces for each length direction (MD) and width direction (TD) Were measured and the average value thereof was taken as the evaluation result.
(2)
Physical properties of carrier film (breaking stress, breaking elongation, initial tensile (at 1% elongation) stress)
Three test pieces were measured for each of the length direction (MD) and the width direction (TD) under the same measurement conditions using the above-described measurement apparatus, and the average value thereof was taken as the evaluation result.
(3)
Drilling accuracy ◎
It was possible to perforate at a predetermined position, and the perforated wall was clean.
○
Drill in place.
× 1 The drilling position was shifted from the predetermined position, and the drilling shape was distorted.
X2 The laminated film was swung, and the position of the new perforated part overlapped with the previous perforated part.
(4)
Film transportability during punching operation
There was no swinging of the film and no pulling wrinkles, and perforation could be continued without any trouble.
× 1 At first, the film was perforated neatly together with the perforated film, but the laminated film was cut by the tension during conveyance after perforation, and the perforation operation could not be continued.
X2 When the laminated film was adjusted so as not to cause pulling wrinkles, the film shook and the perforation position was not stable.
X3 Cutting of the carrier film is incomplete, causing a drag phenomenon due to the uncut portion, and the laminated film is pulled and swung along the top and bottom of the convex blade.

[Example 1]
An adhesive solution prepared by dissolving 100 parts by mass of paramilion AF-36 (easily water-soluble urethane resin, solid content 35 mass%, manufactured by Ohara Palladium Co., Ltd.) as an adhesive in 600 ml of an organic solvent IPA (isopropyl alcohol) is used as a carrier film. Was applied to a copper foil with a thickness of 35 μm so that the thickness after drying was 0.5 μm, and dried in hot air at 100 ° C. for 2 minutes to prepare a carrier film with an adhesive layer. A PPS (polyphenylene sulfite) film having a width of 48 mm for punching and a thickness of 12 μm was superposed on the adhesive layer side surface of this carrier film, and laminated at a roll temperature of 80 ° C. using a roll laminator to obtain a laminated film. .

  The obtained laminated film is composed of a pair of convex blades and concave blades corresponding to the intended circular hole of 300 μmφ, and can be intermittently perforated in the width direction and the length direction by a drive device that can control the position of the perforated part. Through a single-hole type press punching machine, punching test is carried out at a rate of 100 holes per minute over 350 mm pitch in the width direction of the laminated film and 1000 mm length in the length direction of 350 μm pitch. The drilling operation was advanced as a target, and the deformation of the carrier film was observed during that time. After the perforation treatment, the PPS film was obtained by separating the perforated PPS film by dissolving the adhesive between the PPS film perforated by washing with water and the carrier film. The shape of the perforated holes in the separated PPS film was observed, and the results and the physical properties of the used carrier film are shown in Table 1.

[Example 2] to [Example 4]
As Examples 2 to 4, the used carrier films were Torelina (PPS resin film, manufactured by Toray Industries, Inc.) with a thickness of 38 μm, Lumirror 38E20 (polyester film, manufactured by Toray Industries, Inc.) with a thickness of 10 μm, and 10 μm of aluminum. A laminate film test piece was prepared in the same manner as in Example 1 except that the laminate was a laminate of a foil and a polyester film having a thickness of 25 μm, and the punching operation proceeded in the same manner. The shape of the formed holes was observed. These results and the physical properties of the carrier film used are shown in Table 1.

[Comparative Example 1] to [Comparative Example 2]
As Comparative Examples 1 and 2, a laminated film was used in exactly the same manner as in Example 1 except that the carrier film used was replaced with an aluminum foil with a thickness of 30 μm and Lumirror 38S10 (polyester film, manufactured by Toray Industries, Inc.) with a thickness of 38 μm. The test piece was prepared and the perforation operation proceeded in the same manner, and the deformation of the laminated film and the shape of the perforated hole were observed during that time. These results and the physical properties of the carrier film used are shown in Table 1.

[Reference Example 1] to [Reference Example 3]
In Example 1, in place of the perforating film, a [PS 1] film having a thickness of 12 μm, a PPS film having a thickness of 16 μm, and a PPS film having a thickness of 25 μm were used as [Reference Example 1] to [Reference Example 3], respectively. Further, except for not laminating the carrier film, the perforation operation was advanced in the same manner as in Example 1, the behavior of the perforating film during the operation and the shape of the perforated holes were observed, and these results were used for perforation. Table 1 shows the physical properties of the film.

(Summary of experimental results)
As is clear from the results in Table 1, even when the initial tensile stress (at 1% elongation) of the perforating film is small, the carrier film is laminated and the breaking stress is 80 N / 15 mm width or more, the breaking elongation. However, when perforated in the state of a laminated film in which the initial tensile stress boundary value (at 1% elongation) was reinforced to 8 N / 15 mm width or more, there was no displacement of the perforation position, and the perforation could be continued continuously. In Comparative Example 1, since the breaking stress of the carrier film is too small, the breaking stress of the laminated film is also small, and it cannot be cut during perforation to serve as a carrier film. Comparative Example 2 (breaking elongation is 155) %)), The carrier film in the hole is not completely separated even when drilling during the cutting operation, and a drag phenomenon occurs due to the remaining part of the cutting. Tensioned by the laminated film perforation position is continuously swung, eventually laminated film was cut. In addition, although Reference Example 2 is not a laminated film, if the breaking stress is less than 80 N / 15 mm width and the initial tensile stress boundary value (at 1% elongation) is less than 8 N / 15 mm width, tensile wrinkles occur and the perforated shape is distorted. When the tension was lowered to avoid this, the film began to swing. In Reference Example 3, the breaking stress of the perforated film is 80 N / 15 mm width or more, the initial tensile stress boundary value (when 1% stretched) is 8 N / 15 mm width or more, the carrier film transportability is stable, and the perforated shape is accurate. Met.

The laminated film of the present invention is a film for perforation having a small initial tensile (at 1% elongation) stress, and a carrier film is laminated through a water-soluble adhesive layer so that the breaking stress is 80 N / 15 mm width or more. The initial shape can be continuously perforated in the state of passing through the process by reinforcing the strength to be 155% or less and the initial tensile (at 1% elongation) stress to be 8 N / 15 mm width or more, After the perforation, the carrier film layer is peeled and removed, so that the perforation position can be continuously perforated without shifting and the industrial effect is great.

Claims (5)

When continuously perforating a perforated film having a low initial tensile stress (at 1% elongation) while passing through the process, the carrier film is laminated through a water-soluble adhesive layer, and the breaking stress is 80 N / The carrier film layer is peeled and removed after perforation in the state of a laminated film reinforced to have a width of 15 mm or more, a breaking elongation of 155% or less, and an initial tensile (at 1% elongation) stress of 8 N / 15 mm width or more. A method for perforating a film having a small initial tensile (at 1% elongation) stress.
When continuously and densely perforating a film for punching with a low initial tensile stress (at 1% elongation) through the process, the carrier film is laminated via a water-soluble adhesive layer to break stress. Is pierced in the state of a laminated film reinforced so that the elongation is 100 N / 15 mm width or more, the breaking elongation is 155% or less, and the initial tensile stress (at 1% elongation) is 16 N / 15 mm width or more, and then the carrier film layer is peeled off A method for perforating a film having a low initial tensile (at 1% elongation) stress.
The method for perforating a film having a small tensile stress according to claim 1 or 2, wherein the peeling method is performed by immersing the perforated laminated film in an aqueous solvent.
The reinforced laminated film according to claim 1 or 2.
A perforated film obtained by perforating in the state of the laminated film according to claim 4 and then peeling and removing the carrier film layer.