JP2021084364A - Laminating device and manufacturing method of laminated film - Google Patents

Abstract

To provide a laminating device that can reduce the winding pressure without adding new equipment.SOLUTION: The laminating device of the present invention satisfies, in the nip section, at least one of the following: the heating temperature for both ends in the width direction of a plurality of films is lower than the heating temperature for the center in the width direction of the plurality of films; and the pressure for both ends in the width direction of the plurality of films is smaller than the pressure for the center in the width direction of the plurality of films.SELECTED DRAWING: Figure 4

Description

The present invention relates to a laminating apparatus and a method for producing a laminated film.

A laminating device is known as a device for laminating a plurality of films to form a laminated film. In the laminating apparatus, as shown in Patent Document 1, a laminated film can be formed by thermocompression bonding a plurality of films.

However, when the film is conveyed between a plurality of rollers for processing as in a laminating device, a winding pressure is applied to the winding roller that winds the film. This tightening pressure can cause the film to wrinkle. Therefore, in order to reduce the influence of the winding pressure on the winding roller on the film, there is known a method of providing an adhesive tape as a spacer at the end portion of the film in the width direction as shown in Patent Document 2. As a result, the end portion of the film becomes relatively thick, and the central portion of the film does not come into contact during winding, so that the influence of the winding pressure at the central portion of the film can be reduced.

Japanese Unexamined Patent Publication No. 2014-233918 Japanese Unexamined Patent Publication No. 2013-010901

By applying the method described in Patent Document 2 to the laminating apparatus, the end portion of the film can be made relatively thick to reduce the winding pressure. However, for that purpose, a step of processing the end portion of the film is further required. A new device is required to add a process for processing the end portion of the film, which leads to an increase in cost.

Therefore, an object of the present invention is to provide a laminating device capable of reducing the winding pressure without increasing the number of new devices. Another object of the present invention is to provide a method for producing a laminated film capable of reducing the winding pressure without increasing the number of new steps.

The laminating apparatus according to the present invention is
With multiple unwinding rollers that supply multiple films, respectively.
A pair of heating rollers forming the nip,
A take-up roller that winds up the laminated film and
Have,
A laminating device for forming a laminated film by thermocompression bonding the plurality of films by passing the plurality of films through the nip portion.
In the nip part
The heating temperature for both ends in the width direction of the plurality of films is lower than the heating temperature for the center portion in the width direction of the plurality of films, and
The pressure on both ends in the width direction of the plurality of films is smaller than the pressure on the center portion in the width direction of the plurality of films.
It is characterized by satisfying at least one of.

Further, another laminating device according to the present invention is
With multiple unwinding rollers that supply multiple films, respectively.
A heating roller having a contact portion in contact with the plurality of membranes,
A take-up roller that winds up the laminated film and
Have,
The unwinding roller and the winding roller are tension applying means for applying tension to the plurality of films and the laminated film.
The plurality of films are brought into contact with the heating roller so that the winding angle at the contact portion is larger than 0 ° in a state where tension is applied to the plurality of films by the tension applying means. Is a laminating device that forms a laminated film by thermocompression bonding.
At the contact part
The heating temperature for both ends in the width direction of the plurality of films is lower than the heating temperature for the center portion in the width direction of the plurality of films, and
The pressure on both ends in the width direction of the plurality of films is smaller than the pressure on the center portion in the width direction of the plurality of films.
It is characterized by satisfying at least one of.

Further, the method for producing a laminated film according to the present invention is as follows.
A method for producing a laminated film, which comprises a thermocompression bonding step of forming a laminated film by thermocompression bonding a plurality of films.
In the thermocompression bonding step
The heating temperature to both ends in the width direction of the plurality of films is lower than the heating temperature to the center portion in the width direction of the plurality of films, and
The pressure on both ends in the width direction of the plurality of films is smaller than the pressure on the center portion in the width direction of the plurality of films.
It is characterized by satisfying at least one of.

According to the present invention, it is possible to provide a laminating device capable of reducing the winding pressure without increasing the number of new devices. Further, it is possible to provide a method for producing a laminated film capable of reducing the winding pressure without increasing the number of new steps.

It is a nip type laminating device. It is a nipless type laminating device. It is sectional drawing in the width direction of the winding roller 24 and the laminated film 14 which increased the thickness of both ends. It is sectional drawing in the width direction of the heating roller and the laminated film of 1st Embodiment. It is sectional drawing in the width direction of the heating roller and the laminated film of the 2nd Embodiment. It is sectional drawing in the width direction of the heating roller and the laminated film of 3rd Embodiment. It is sectional drawing in the width direction of the heating roller and the laminated film of 4th Embodiment.

Hereinafter, the present invention will be described in more detail with reference to embodiments of the present invention.

[Laminated film]
In the present invention, the number of layers constituting the laminated film is not particularly limited, but it is preferable to select from the range of 2 to 5 layers. Each layer constituting this laminated film is bonded between each layer, and retains the strength as a laminated film.

Each layer constituting the laminated film includes at least one adhesive layer. In the present invention, the adhesive layer is a layer that has a lower softening point than the constituent materials of other layers and is softened by heating at the time of laminating. The layer to be adhered is a layer to be adhered by the adhesive layer. A layer that has a relatively high softening point and is not softened during laminating. Further, the "softening point" refers to the melting point when the material constituting the layer has a melting point, and refers to the glass transition point when the material having no melting point has a glass transition point.

Further, the plurality of films used for forming the laminated film may be a porous film. When a laminated film is used as the liquid absorbing member, it is preferable that all of the plurality of films are porous films.

[Laminating device]
Examples of the laminating device include the nip-type laminating device shown in FIG. 1 and the nipless-type laminating device shown in FIG.

The nip type laminating device and the nipless type laminating device will be described below.

The nip-type laminating device 1 shown in FIG. 1 is a laminating device that forms a laminated film by laminating three films of a first film 11, a second film 12, and a third film 13 by thermocompression bonding. is there. The first film 11 is a film for forming a first layer in the laminated film, the second film is a film for forming a second layer in the laminated film, and the third film is a third film in the laminated film. It is a film for layer formation.

The laminating device 1 includes unwinding rollers 21, 22, and 23, a pair of heating rollers 41 and 42, a winding roller 24, and rollers 31, 32, 33, and 34. An air clutch (not shown) is attached to the unwinding roller 21 (first tension applying means or the first roller), and the unwinding roller 21 is set on the unwinding roller 21 from the roll 11R of the first membrane. The first film 11 is unwound with a constant tension, and the first film is supplied. The unwinding rollers 22 and 23 (second tension applying means and third tension applying means, or second roll and third roll) are similarly attached with an air clutch. Then, the second film 12 and the third film 13 are unwound from the roll 12R of the second film and the roll 13R of the third film set on the unwinding rollers 22 and 23 with a constant tension, respectively. A second film and a third film are supplied. In the present embodiment, the unwinding rollers 21, 22, and 23 employ a tension control method using an air clutch, but the tension control method is not limited to this, and a tension detection sensor and a dancer roller are used. Tension may be controlled using a feedback method.

The pair of heating rollers 41 and 42 each have a heat source inside, and can maintain a surface covered with metal within a predetermined temperature range. The type of heat source is not particularly limited, but an electric heating type, an induction heating type, or the like may be used. A motor (not shown) is attached to the heating roller 41, and the heating roller 41 can rotate at a predetermined speed. A linear actuator (not shown) is attached to the heating roller 42 and can move in parallel with the heating roller 41 to control the nip pressure between the heating roller 41 and the heating roller 42, or to heat from the heating roller 41. The rollers 42 can be separated. In the present embodiment, the two heating rollers are provided with heat sources, but one of the heating rollers may be replaced with a roller that does not have a heat source inside.

An air clutch (not shown) is attached to the take-up roller 24 (fourth tension applying means or fourth roller), and the first film 11, the second film 12, and the third film 13 are attached. The laminated film 14 obtained by laminating the above is wound up with a constant tension. Then, the roll 14R of the laminated film is formed. In the present embodiment, the take-up roller 24 employs a tension control method using an air clutch, but the tension control method is not limited to this, and tension is applied by using a tension detection sensor or a feedback method using a dancer roller. May be controlled.

Further, in the present embodiment, a motor, which is a drive source for continuously transporting the film, is attached to the heating roller 41, but the present invention is not limited to this. For example, the heating roller is not provided with a motor, and a method of niping and sending out the laminated film 14 on the downstream side in the transport direction of the laminated film 14 of the heating roller 41 or a method of attaching a motor to the take-up roller 24 is used. May be good.

Next, the nipless type laminating apparatus 2 shown in FIG. 2 will be described.

In the nipless type laminating device 2 shown in FIG. 2, one heating roller is used instead of the pair of heating rollers 41 and 42 of the nip type laminating device 1 shown in FIG. Then, a plurality of films composed of the first film, the second film, and the third film are tensioned on the plurality of films by the unwinding rollers 21, 22, 23, and the winding roller 24, which are tension applying means. Is added. In this state, the plurality of films are thermocompression-bonded to form the laminated film 14 by contacting the heating roller 51 so that the winding angle at the contact portion with the heating roller 51 is larger than 0 °. The other nipless type laminating device 2 can have the same configuration as the nip type laminating device 1.

[Manufacturing method of laminated film]
A method for manufacturing a laminated film will be described.

The method for producing a laminated film includes a thermocompression bonding step of forming a laminated film by thermocompression bonding a plurality of films. Of the laminated films, the adhesive layer is preferably arranged at a position where it does not come into direct contact with the heating roller.

In the laminating apparatus shown in FIGS. 1 and 2, the number of layers constituting the laminated film is three, but the present invention is not limited to this. In addition, the first film, the second film, and the third film used for laminating may each have a single layer or a multi-layer structure. Further, among the laminated films, one or more films closest to the heating roller are used as a protective film when thermocompression bonding is performed, and after the thermocompression bonding process, the film is peeled off and wound on a roller different from the winding roller 24. May be good.

The heating temperature and the pressure applied to the plurality of films in the thermocompression bonding process are selected so that the thermocompression bonding between the films can obtain the desired adhesion strength without impairing the physical properties and characteristics of each film. ..

The heating temperature (surface temperature of the heating roller) for the plurality of films in the thermocompression bonding step is preferably equal to or higher than the softening point of the material contained in the adhesive layer. Further, the heating temperature for the plurality of films in the thermocompression bonding step is preferably lower than the softening point of the material contained in the layer to be adhered. The surface temperature of the heating roller in the present embodiment is preferably 10 to 50 ° C. higher than the softening point of the material of the adhesive layer and lower than the softening point of the material of the adhesive layer.

The pressure applied to the plurality of films during the thermocompression bonding step is controlled by the nip pressures of the pair of heating rollers 41 and 42 in the laminating apparatus of FIG. This nip pressure can be adjusted by a linear actuator attached to the heating roller 42. The nip pressure of the heating rollers 41 and 42 is preferably equal to or higher than the pressure at which the softened adhesive layer material adheres to the adhesive layer material. Further, in the laminating apparatus of FIG. 2, it is controlled by the winding angles of the plurality of films at the contact portion of the heating roller 51 and the tension of the tension applying means.

The process of the manufacturing method of the laminated film will be described.

First, a plurality of films (first film, second film, third film) sent out under tension are overlapped and laminated on the transport path. Subsequently, the laminated film before bonding is heated and pressurized by passing through the nip portion between the heating roller 41 and the heating roller 42, and the first film 11, the second film 12, and the third film 3 are heated. The film 13 of the above forms a laminated film 14 that is thermocompression bonded. The laminated film 14 thus obtained is wound up by a winding roller and stored.

Further, the laminating apparatus of FIG. 1 is a nip method in which the heating roller 42 is pressed against the heating roller 41 by a linear actuator and thermocompression bonding is performed, but the present invention is not limited to this. For example, as shown in FIG. 2, the first film 11, the second film 12, and the third film 13 are pressed against the heating roller 41 by the tension related to these films without using the heating roller 42. A nipless method of heating and pressurizing and laminating may be used.

By heating and pressurizing in the laminating apparatus, the adhesive layer is softened by heating and then deformed by pressurization. Further, since a part of the softened adhesive layer permeates and adheres to the adhesive layer, the thickness of the formed laminated film is the thickness of the first film, the second film, and the third film. It is smaller than the total. The amount of change in the thickness can be adjusted according to the conditions of thermocompression bonding. For example, the thermocompression bonding conditions can be changed so that the thickness of the edge portion of the laminated film is larger than the thickness of the central portion of the laminated film. As a result, when the laminated film 14 is wound by the take-up roller 24 without increasing the number of new processes or new devices, the winding tightening pressure is applied to both ends in the width direction of the laminated film, and the width of the laminated film 14 is applied. It is possible to reduce the pressure due to winding in the central part of the direction.

FIG. 3A shows a cross-sectional view of the take-up roller 24 and the laminated film 14 having thickened both ends in the width direction. Further, FIG. 3 (b) is an enlarged view of the region X in FIG. 3 (a). As shown in FIG. 3B, since the end portions of the laminated film 14 are formed to be thick, the laminated films 14 wound around the winding roller 24 are in contact with each other at the center portions. Since there is no winding pressure, the winding pressure is concentrated on the end portion of the laminated film 14. Further, the larger the diameter of the take-up roller 24, the smaller the number of windings and the smaller the winding tightening pressure. Therefore, the diameter of the take-up roller 24 is preferably 150 mm to 200 mm. Since it is desirable that the central portions of the laminated films do not come into contact with each other when wound up, the difference in thickness between both ends and the central portion of the laminated films should be greater than or equal to the amount of deflection of the central portion due to the weight of the laminated films. preferable.

With the above method for manufacturing a laminated film, the winding pressure at the central portion can be reduced by making a difference in the thickness between the end portion and the central portion of the laminated film without adding a step. The heating roller plays an important role because the condition of thermocompression bonding that allows the difference in thickness between the edge and the center of the laminated film depends on the heating temperature and pressure for a plurality of films. The heating rollers according to the first to fourth embodiments will be described below. As the laminating apparatus according to the first to fourth embodiments, the one having the configuration shown in FIG. 1 was used.

(First Embodiment)
The first embodiment of the present invention will be described with reference to FIG.

FIG. 4A is a cross-sectional view of the heating rollers 41 and 42 and the laminated film in the width direction in the laminating apparatus of the first embodiment. Further, FIG. 4 (b) is an enlarged view of the region X of FIG. 4 (a). In this embodiment, the widths of the heating rollers 41 and 42 are narrower than the widths of the first film, the second film, and the third film. As a result, each film is thermocompression bonded in a state of protruding from both ends of the heating roller. No heating or pressurization is performed at the edge of the film protruding from the heating roller. That is, the heating temperature for both ends in the width direction of the plurality of films is lower than the heating temperature for the central portion in the width direction of the plurality of films, and the pressure for both ends in the width direction of the plurality of films is the width of the plurality of films. The pressure is smaller than the pressure on the central part in the direction. Therefore, the thickness of the edge portion of the laminated film can be made larger than the thickness of the central portion.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG.

FIG. 5A is a cross-sectional view of the heating rollers 41 and 42 and the laminated film in the width direction in the laminating apparatus of the second embodiment. Further, FIG. 5 (b) is an enlarged view of the region X of FIG. 5 (a). In this embodiment, the heating roller has a tapered shape portion in which the diameters of both ends in the longitudinal direction are smaller than the diameter of the central portion in the longitudinal direction. As a result, the pressure applied to each film during thermocompression bonding is smaller at both ends than at the center, so that the thickness at both ends of the laminated film can be made larger than the thickness at the center. In the second embodiment, since the thickness of both ends of the laminated film is larger than that of the central portion, the winding pressure at the central portion can be reduced. Further, since the films are in close contact with each other at both ends, even when the films on the front surface and the back surface of the laminated film are relatively soft, it is possible to prevent the end portions of the laminated film from being woven into the central portion side at the time of winding.

(Third Embodiment)
A third embodiment of the present invention will be described with reference to FIG.

FIG. 6A is a cross-sectional view of the heating rollers 41 and 42 and the laminated film in the width direction in the laminating apparatus of the third embodiment. Further, FIG. 6 (b) is an enlarged view of the region X of FIG. 6 (a). In this embodiment, the heating roller is composed of materials having different heat transfer coefficients at the center and both ends of the heating roller so that the heat transfer coefficient at both ends of the heating roller is smaller than the heat transfer coefficient at the center. ing. As a result, the temperature applied to each film during thermocompression bonding is smaller at both ends than at the center, so that the thickness at both ends of the laminated film can be made larger than the thickness at the center. In the third embodiment, since the thickness of both ends of the laminated film is larger than that of the central portion, the winding pressure at the central portion can be reduced. Further, since the films are in close contact with each other at both ends, even when the films on the front surface and the back surface of the laminated film are relatively soft, it is possible to prevent the end portions of the laminated film from being woven into the central portion side at the time of winding.

(Fourth Embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. 7.

FIG. 7A is a cross-sectional view of the heating rollers 41 and 42 and the laminated film in the width direction in the laminating apparatus of the fourth embodiment. Further, FIG. 7 (b) is an enlarged view of the region X of FIG. 7 (a). In this embodiment, the heating roller has a stepped shape in which the diameters of both ends in the longitudinal direction are smaller than the diameter of the central portion in the longitudinal direction. As a result, as in the second embodiment, the pressure applied to each film during thermocompression bonding is smaller at both ends than at the center, so that the thickness of both ends of the laminated film is smaller than the thickness of the center. Can also be increased. In the fourth embodiment, since the thickness of both ends of the laminated film is larger than that of the central portion, the winding pressure at the central portion can be reduced. Further, since the films are in close contact with each other at both ends, even when the films on the front surface and the back surface of the laminated film are relatively soft, it is possible to prevent the end portions of the laminated film from being woven into the central portion side at the time of winding. Further, in the fourth embodiment, since there is a step at the boundary between both end portions and the central portion of the heating roller, the boundary between the end portion and the central portion can be visually easily understood even in the laminated film. Therefore, workability is improved when the end portion of the laminated film is separated by slitting in a subsequent process. Therefore, when slitting, the fourth embodiment is more suitable than the second and third embodiments.

The above-mentioned four heating roller embodiments may be used alone or in combination of two or more. Further, the above four heating roller embodiments may be applied to only one of the heating rollers 41 and 42. Further, instead of the heating rollers 41 and 42, the heating rollers 51 used in the nipless type laminating apparatus shown in FIG. 2 may be used.

Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

First, the laminated porous membrane used in Examples 1 to 4 and Comparative Example 1 will be described.

The first layer-forming porous film 11 is a film composed of polytetrafluoroethylene (softening point 320 ° C.), and has a thickness of 2 μm and a width of 850 mm. The second layer-forming porous film 12 is a film composed of fibers having a core-sheath structure in which the core structure is polypropylene (softening point 160 ° C.) and the sheath structure is polyethylene (softening point 130 ° C.). It has a thickness of 70 μm and a width of 850 mm. The third layer-forming porous film is a film composed of fibers having a core-sheath structure in which the core structure is polypropylene (softening point 160 ° C.) and the sheath structure is polyethylene (softening point 130 ° C.), and is thick. It has a size of 50 μm and a width of 850 mm. The fourth layer-forming porous film is a film composed of polyphenylene sulfide (softening point 260 ° C.), and has a thickness of 210 μm and a width of 850 mm.

The porous film for forming the third layer and the porous film for forming the fourth layer were thermocompression-bonded in advance, and this laminated film was designated as the porous film 13. The thickness of the porous membrane 13 is 250 μm. At the time of laminating, the porous film 11, the porous film 12, and the porous film 13 are arranged in this order so that the first layer, the second layer, the third layer, and the fourth layer are formed in this order from the top. It was arranged and a laminated porous film was formed using the laminating apparatus shown in FIG.

The thickness of each porous film was measured by measuring the film thickness at any 10 points with a straight-ahead micrometer OMV_25 (manufactured by Mitutoyo), and the average value was calculated as the thickness of the porous film. The softening point is measured from the peak value of the endothermic amount obtained by using a DSC measuring device (Q-1000 (trade name), manufactured by TA Instruments Japan Co., Ltd.), DSC (differential difference). It is a value obtained by scanning calorimetry). When a plurality of materials are included, the softening points in the state where the plurality of materials are included are described.

In the laminating apparatus used in the examples, the diameter of the take-up roller 24 was 80 mm, and the take-up tension was 500 N. The tension applied to the porous membrane 11 was 3N, the tension applied to the porous membrane 12 was 30N, and the tension applied to the porous membrane 13 was 470N. In the heating roller 51, the linear velocity on the surface of the central portion was set to 8.2 mm / sec. The thermocompression bonding time at this time is 8 seconds. The temperature of the central surface of the heating roller was 150 ° C., and the winding angle at the contact portion of the porous film with the heating roller 51 was 30 ° C. Here, the winding angle is a heating roller in a region where the porous film 13, which is the film farthest from the heating roller 41, is in contact with the heating roller 51 via the porous films 11 and 12 and is heated. It is an angle with respect to the rotation axis of 51. In the present invention, the surface temperature of the heating roller is a value obtained by measuring the temperature of any 10 points using a thermocouple thermometer TS-001 and a sensor probe T-004 manufactured by Ai Denshi Giken and calculating the average value thereof. is there.

(Example 1)
As the heating roller 51 of the laminating apparatus, a cylindrical iron heating roller having a radius of 125 mm and a width of 750 mm was used. The width of the heating roller 51 is narrower than the width of each of the porous membranes 11, 12, and 13. Therefore, each porous film was thermocompression bonded in a state of protruding from both ends of the heating roller.

(Example 2)
As the heating roller 51 of the laminating apparatus, an iron heating roller having a radius of 124 mm at both ends, a radius of 125 mm at the center portion, and a width of 850 mm and having a tapered shape portion was used. The heating roller has a tapered portion in which the diameters of both ends in the longitudinal direction are smaller than the diameter of the central portion in the longitudinal direction. Therefore, the pressure applied to each of the porous films 11, 12, and 13 during thermocompression bonding was smaller at both ends than at the center.

(Example 3)
As the heating roller 51 of the laminating apparatus, a cylindrical copper heating roller having a radius of 125 mm and a width of 850 mm was used. The surface of the central portion of the heating roller was made of iron, and the surface of the end portion 50 mm from both ends was made of nickel, which has a lower heat transfer coefficient than copper. The surface temperature of the heating roller 41 was 150 ° C. at the center and 130 ° C. at the ends. The heating roller is composed of materials having different heat transfer coefficients at the center and both ends of the heating roller so that the heat transfer coefficient at both ends of the heating roller is smaller than the heat transfer coefficient at the center. Therefore, the temperature applied to each porous film during thermocompression bonding was smaller at both ends than at the center.

(Example 4)
As the heating roller 51 of the laminating apparatus, an iron heating roller having a radius of 124 mm in a range of 50 mm from both ends, a radius of 125 mm at the center, and a width of 850 mm and having a stepped shape was used. The heating roller has a stepped shape in which the diameters of both ends in the longitudinal direction are smaller than the diameter of the central portion in the longitudinal direction. Therefore, the pressure applied to each of the porous films 11, 12, and 13 during thermocompression bonding was smaller at both ends than at the center.

(Comparative Example 1)
As the heating roller 51 of the laminating apparatus, a cylindrical iron heating roller having a radius of 125 mm and a width of 850 mm was used. The width of the heating roller is the same as the width of each of the porous membranes 11, 12, and 13. Therefore, the heating temperature and pressure for each of the porous films 11, 12, and 13 during thermocompression bonding were the same at the central portion and both ends.

[Evaluation]
The laminated porous membranes obtained in Examples 1 to 4 and Comparative Example 1 were evaluated by the following methods.

Specifically, using a roll of laminated porous membrane after laminating and winding for 20 m and storing for a certain period of time, breathability on the innermost and outermost sides of the roll, presence or absence of pinching at the end, and the end We evaluated the presence or absence of the boundary between the center and the center. At this time, the reason why the air permeability was used for the evaluation of the winding pressure is that the air permeability of the porous membrane decreases due to the application of pressure.

The evaluation results are shown in Table 1.

<Breathability>
Breathability was evaluated using the Garley value measured by the Garley testing machine specified in JIS P8117. The evaluation criteria in Table 1 are as follows.

X: The difference in the Garley value between the innermost central portion of the roll of the laminated porous membrane and the outermost central portion of the roll of the laminated porous membrane is 1 second or more.

◯: The difference in the Garley value between the innermost central portion of the roll of the laminated porous membrane and the outermost central portion of the roll of the laminated porous membrane is less than 1 second.

<Pinching the end>
The entrainment of the end portion of the laminated porous film after winding was visually evaluated. The evaluation criteria in Table 1 are as follows.

X: When the laminated porous film 20 m is wound, there is one or more entanglements of the end material in the central portion.

◯: When the laminated porous film 20 m is wound, there is no entanglement of the end material in the central portion.

<Boundary between edge and center>
The entrainment of the end portion of the laminated porous film after winding was visually evaluated. The evaluation criteria in Table 1 are as follows.

X: The boundary between the edge and the center cannot be visually confirmed.

◯: The boundary between the edge and the center can be visually confirmed.

In Comparative Example 1, the boundary between the edge and the center was not evaluated.

1 Laminating device 11 1st film 12 2nd film 13 3rd film 14 Laminated film 21 1st film unwinding roller 22 2nd film unwinding roller 23 3rd film unwinding roller 24 winding Tori roller 41, 42 Heating roller

Claims (8)

With multiple unwinding rollers that supply multiple films, respectively.
A pair of heating rollers forming the nip,
A take-up roller that winds up the laminated film and
Have,
A laminating device for forming a laminated film by thermocompression bonding the plurality of films by passing the plurality of films through the nip portion.
In the nip part
The heating temperature for both ends in the width direction of the plurality of films is lower than the heating temperature for the center portion in the width direction of the plurality of films, and
The pressure on both ends in the width direction of the plurality of films is smaller than the pressure on the center portion in the width direction of the plurality of films.
A laminating device characterized by satisfying at least one of the above. With multiple unwinding rollers that supply multiple films, respectively.
A heating roller having a contact portion in contact with the plurality of membranes,
A take-up roller that winds up the laminated film and
Have,
The unwinding roller and the winding roller are tension applying means for applying tension to the plurality of films and the laminated film.
The plurality of films are brought into contact with the heating roller so that the winding angle at the contact portion is larger than 0 ° in a state where tension is applied to the plurality of films by the tension applying means. Is a laminating device that forms a laminated film by thermocompression bonding.
At the contact part
The heating temperature for both ends in the width direction of the plurality of films is lower than the heating temperature for the center portion in the width direction of the plurality of films, and
The pressure on both ends in the width direction of the plurality of films is smaller than the pressure on the center portion in the width direction of the plurality of films.
A laminating device characterized by satisfying at least one of the above. The laminating apparatus according to claim 1 or 2, wherein the width of the heating roller in the longitudinal direction is smaller than the width of the plurality of films. The laminating apparatus according to any one of claims 1 to 3, wherein the heat transfer coefficient of both ends of the heating roller is smaller than the heat transfer coefficient of the central portion of the heating roller. The laminating device according to any one of claims 1 to 4, wherein the heating roller has a diameter of both ends in the longitudinal direction smaller than the diameter of the central portion in the longitudinal direction and has a tapered shape portion. The laminating device according to any one of claims 1 to 4, wherein the heating roller has a stepped shape in which the diameters of both ends in the longitudinal direction are smaller than the diameter of the central portion in the longitudinal direction. The laminating apparatus according to any one of claims 1 to 6, wherein the plurality of films are all porous films. A method for producing a laminated film, which comprises a thermocompression bonding step of forming a laminated film by thermocompression bonding a plurality of films.
In the thermocompression bonding step
The heating temperature for both ends in the width direction of the plurality of films is lower than the heating temperature for the center portion in the width direction of the plurality of films, and
The pressure on both ends in the width direction of the plurality of films is smaller than the pressure on the center portion in the width direction of the plurality of films.
A method for producing a laminated film, which comprises satisfying at least one of the above.

Images