JP2017052266A - Lamination apparatus and manufacturing method of laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamination apparatus and a manufacturing method of a laminated film in which films can be laminated while deformation of the films is suppressed.SOLUTION: A lamination apparatus according to the present invention has: a heating roller which is capable of maintaining a surface at a predetermined temperature; first tensile force applying means for applying tensile force to a first film; second tensile force applying means for applying tensile force to a second film; and third tensile force applying means for applying tensile force to a laminated film which is formed by laminating the first film and the second film, in which the first film and the second film are firmly bonded so as to be laminated in this order against one heating roller, and a winding angle of the first film and the second film are constituted to become larger than 0°.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminating apparatus for laminating a plurality of films to form a laminated film and a method for producing the laminated film.

  When a laminated film is formed by laminating a plurality of films, a method of pressing the film while applying heat at a temperature at which the film melts is generally used. For example, as an apparatus for laminating a plurality of films, as shown in Patent Document 1, a plurality of films are stacked and supplied between a pair of heating rollers that are rotationally driven. An apparatus for sandwiching and laminating is known. This apparatus is also called a nip roller type laminating apparatus.

JP 2014-233918 A

  In the nip roller type laminating apparatus represented by Patent Document 1, the range of pressing by applying heat is limited to the pressure contact surface between the pair of heating rollers. At this time, the area of the pressure contact surface is extremely small because it is a pressure contact surface between the heating rollers that are cylindrical bodies, and the actual lamination time is shortened.

  Therefore, for example, when the film to be laminated is a material that is easily deformed by pressure, such as a porous film, the nip roller type laminating apparatus has a short laminating time, so the controllability is poor and the film is prevented from being deformed. Difficult to stick together.

  Accordingly, an object of the present invention is to provide a laminating apparatus and a method for producing a laminated film that can bond the films together while suppressing deformation of the films.

  The laminating apparatus according to the present invention includes a first layer formed by the first film and the second film formed by thermocompression bonding the first film and the second film. A laminating apparatus for forming a laminated film having two layers, a first heating roller capable of maintaining a surface at a predetermined temperature, and a first tension for applying tension to the first film An adding means; a second tension applying means for applying tension to the second film; and a third tension for applying tension to the laminated film obtained by laminating the first film and the second film. And the first film and the second film are in close contact with each other on the one heating roller, and the first film and the second film are in close contact with each other. The winding angle of the film is configured to be larger than 0 °.

  Further, another laminating apparatus according to the present invention includes a first layer formed by the first film by thermocompression bonding the first film and the second film, and the second film. A laminating apparatus for forming a laminated film having a second layer to be formed, a heating roller capable of maintaining a surface at a predetermined temperature, a first roller around which the first film is wound, A second roller around which the second film is wound, and a third roller around which the laminated film is wound, and the first roller, the third roller, and the heating roller allow the first roller The film is tensioned, and the second film is tensioned by the second roller, the third roller, and the heating roller, and the first film is applied to one heating roller. And the second film are stacked in this order. Coherent, and is characterized by being configured such that the first film, and winding angle of the second layer is greater than 0 °.

  In addition, in the method for manufacturing a laminated film according to the present invention, the first film and the second film are thermocompression bonded, the first layer formed by the first film, and the second film A method for producing a laminated film having a second layer formed by the first contact, wherein the first film is brought into contact with a heating roller whose surface is maintained at a predetermined temperature. A second contact step in which the second film is brought into contact with the heating roller through the first film, and a tension applied to the second film, and the second film and the second film A thermocompression bonding step of thermocompression bonding the first film and the second film by bringing the first film into close contact with the heating roller.

  In another method for producing a laminated film according to the present invention, the first film, the second film, and the third film are thermocompression-bonded to form a first film formed by the first film. A method for producing a laminated film, comprising: a layer; a second layer formed by the second film; and a third layer formed by the third film, A first contact step of bringing the first film into contact with a heating roller whose surface is maintained at a predetermined temperature; and a second step of bringing the second film into contact with the heating roller through the first film. Contact step, a third contact step in which the third film is brought into contact with the heating roller via the first film and the second film, and a tension applied to the third film. The third film, the second film, and the first film are brought into close contact with the heating roller, whereby the first film and the second film And having a thermocompression bonding step of thermocompression bonding and said third film and.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the manufacturing method of the lamination apparatus and laminated film which can bond films | membranes together, suppressing a deformation | transformation of a film | membrane.

It is a figure which shows the whole structure of the laminating apparatus in the 1st Embodiment of this invention. FIG. 2 is an enlarged view around a heating roller 20 in FIG. 1. It is a figure which shows the structure of the laminating apparatus of the nip roller system used by the comparative example. It is sectional drawing of the laminated body in the 2nd Embodiment of this invention. In the 2nd Embodiment of this invention, it is a figure which shows the whole structure of the laminating apparatus used for the lamination of the 1st step. In the 2nd Embodiment of this invention, it is a figure which shows the whole structure of the laminating apparatus used for the lamination of a 2nd step. FIG. 7 is an enlarged view around a heating roller 320 in FIG. 6. In the 2nd Embodiment of this invention, it is a figure which shows the whole structure of the laminating apparatus which performs both the 1st step lamination and the 2nd step lamination.

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

  In the embodiment of the present invention described below, a case where a plurality of laminated films are all porous films and a laminated film formed by the plurality of films is a laminated porous film will be described. ing. However, the present invention is not limited to the case where the plurality of laminated films are porous films. Further, the laminated film formed by the plurality of films is not limited to a laminated porous film.

  As embodiments of the present invention, first and second embodiments will be described below, but the embodiments are not limited thereto. In addition, the laminated porous membrane manufactured in the present invention can be used as a member for wiping off the liquid and solid matter attached to the surface to be cleaned with high accuracy. The laminated porous film can also be used as a liquid absorbing member provided in an ink jet recording apparatus having an image forming unit that forms an image containing a liquid and a color material on a recording medium. The liquid absorbing member can contact the image, absorb at least a part of the liquid from the image, and reduce the amount of liquid in the image. Here, if the absorption of the liquid component is described from a different viewpoint, it can also be expressed as concentrating the ink constituting the image formed on the recording medium. Concentrating the ink means that the content ratio of the solid component such as a coloring material or resin contained in the ink increases as the liquid component contained in the ink decreases.

(First embodiment)
Hereinafter, the present invention will be described in detail with reference to the first embodiment of the present invention.

[Laminated porous membrane]
The laminated porous film that is a laminated film manufactured in the first embodiment will be described below.

The laminated porous film has a laminated structure including a first layer made of a first porous film and a second layer made of a second porous film, that is, a structure as a laminated porous film. Each of the first layer and the second layer can be composed of a single layer or a plurality of layers. Note that another layer may be provided on the second layer. Moreover, although you may have another layer between each layer, it is preferable that at least a 1st layer and a 2nd layer are adjacent layers.
The total number of layers constituting the laminated structure of the porous membrane is not particularly limited, but can be selected from a range of 2 to 5. Each layer constituting this laminated structure is bonded between the respective layers, and maintains the strength as a laminated porous film.

  The porosity of the porous membrane can be evaluated by its air permeability. The air permeability can be defined by a Gurley value measured by a Gurley tester defined in JIS P8117. The Gurley value of the entire porous membrane obtained by the production method of the present invention is preferably 10 seconds or less. A lower Gurley value means higher air permeability. The lower limit value of the Gurley value is not particularly limited, but can be set to about 0.3 seconds.

  In the first embodiment, a laminating apparatus and a laminated film for forming a laminated porous film having a first layer formed by a first film and a second layer formed by a second film The manufacturing method will be described.

  Hereinafter, each layer constituting the porous film obtained by the laminating apparatus will be described.

[First layer]
The first layer is made of a porous film. The porous film preferably contains a fluororesin. Specific examples of the fluoropolymer contained in the fluororesin include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and perfluoroalkoxy fluorine. Resin (PFA: perfluoroalkoxyalkane (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), ethylene / tetrafluoroethylene copolymer (ETFE) , Ethylene / chlorotrifluoroethylene copolymer (ECTFE), etc. These resins can be used alone or as a mixture of two or more thereof as necessary. When forming multiple layers with different layers A combination of layers containing fluororesin may be included.

  The thickness of the first layer is preferably 100 μm or less. The thickness of the porous film can be obtained by measuring the layer thickness at any 10 points with a straight-forward micrometer OMV_25 (manufactured by Mitutoyo) and calculating the average value. Moreover, the lower limit of the thickness of the first layer is not particularly limited, and can be set according to the use of the porous membrane, and can be set to about 1 μm, for example.

[Second layer]
The second layer of the porous membrane is a layer for obtaining a good collection force such as liquid and solid content and a sufficient collection capacity by constituting a laminated structure together with the first layer. Therefore, it is preferable that the second layer has a larger air permeability (average pore diameter) than the first layer, and the substance collected in the first layer is accommodated in the second layer, so that a higher collection capacity can be obtained. Can be provided.

  The second layer is preferably a layer having air permeability and a function as a support for the porous membrane. The second layer preferably has higher air permeability than the first layer, that is, has a lower Gurley value than the first layer. Examples of the constituent material of the second layer include fibrous members such as nonwoven fabrics, woven fabrics, and meshes (network nets), and other various porous structures. Among these, from the viewpoints of strength, air permeability, flexibility, workability, and the like, a fibrous member is preferable, and a nonwoven fabric is more preferable. By using a porous film having a lower Gurley value than the first layer forming porous film for forming the second layer, a second layer having higher air permeability than the first layer can be obtained. .

  The material for forming the porous film as the second layer forming member is not particularly limited, but polyolefin (for example, polyethylene (PE), polypropylene (PP), etc.), polyurethane, nylon, polyamide, polyester (for example, polyethylene) And terephthalate (PET)), polysulfone (PSF), fluororesin, and the like. As the fluororesin, those mentioned above for forming the first layer can be used. One of these resins can be used alone or as a composite material in combination of two, for producing a porous film for forming the second layer. When using fibrous members, such as a nonwoven fabric, the fibrous member which consists of a fiber of a single material, and the fibrous member in which the fiber which consists of 2 or more types of different materials can be mixed can be used.

[Multi-layer configuration of second layer]
The second layer of the porous membrane can be formed as a plurality of layers. When the second layer is formed of a plurality of layers, layers having different constituent materials and forms may be used in combination. As the constituent material of each layer when the second layer has a multi-layer structure, those exemplified above can be used. Even when the second layer has a multi-layer structure, it is preferable that the air permeability of the entire multi-layer structure is higher than that of the first layer as described above.

[Laminating equipment]
A laminating apparatus according to a first embodiment of the present invention will be described with reference to FIG.

  A laminating apparatus 1 that forms a laminated film by thermocompression bonding a first film and a second film includes unwinding rollers 21 and 22, a heating roller 20, a winding roller 23, and rollers 31, 32, and 33. Is done. An air clutch (not shown) is attached to the unwinding roller 21 (first tension applying means or the first roller), and the porous film 11 (first layer forming porous film 11 ( The first film is unwound at a constant tension. Similarly, the unwinding roller 22 (second tension applying means or the second roller) also uses an air clutch, and the porous film 12 (second film) for forming the second layer from the set roll 12R. ) At a constant tension. In this embodiment, a tension control method using an air clutch is adopted in unwinding, but the control method is not limited to this, and a feedback method using a tension detection sensor or a dancer roller may be used.

  The heating roller 20 includes a heat source inside, and can maintain the surface covered with metal in a predetermined temperature range. The type of the 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 20 and can rotate at a predetermined speed.

  An air clutch (not shown) is attached to the take-up roller 23 (third tension applying means or the third roller), and a laminate obtained by laminating the porous film 11 and the porous film 12. The porous membrane 13 is wound around the roll 13R with a constant tension. In this embodiment, a tension control method using an air clutch is adopted in winding, but the control method is not limited to this, and a feedback method using a tension detection sensor or a dancer roller may be used.

  Moreover, in this embodiment, although the motor which is a drive source for conveying a porous membrane continuously is attached to the heating roller 20, it is not limited to this. The heating roller may be in an unloaded state, and a method in which the laminated porous film 13 is nipped and sent out on the downstream side of the heating roller or a method in which a motor is attached to the winding roller 23 may be used.

  The configuration around the heating roller 20 as a feature of the present invention will be described with reference to FIG.

  The porous film 11 as the first film and the porous film 12 as the second film are conveyed so as to form a path wound around the heating roller 20. At this time, a winding angle with a start point at which the porous film 12 starts to contact the heating roller 20 via the porous film 11 and a point at which the porous film 12 starts to leave is defined as θ. The rollers 32 and 33 (FIG. 1) are arranged so that the winding angle θ is a predetermined angle. As described above, each of the porous films 11, 12, and 13 is under tension, and is in close contact with the heating roller 20 within the range of the winding angle θ. This winding angle θ is larger than 0 °.

  When the heating roller 20 is rotated by a motor (not shown), the porous film 11 is fed at a predetermined speed by friction between the heating roller 20 and the porous film 11. In addition, the porous film 12 is laminated with the porous film 11 between the winding angles θ, and is sent by adhesion with the porous film 11.

[Laminated film manufacturing method]
The manufacturing method of the laminated film concerning this invention is demonstrated.

  In the method for manufacturing a laminated film according to the present invention, the first film and the second film are thermocompression-bonded to form the first layer formed by the first film and the second film. A laminated film having the second layer to be formed is formed. The manufacturing method of this laminated film has a 1st contact process, a 2nd contact process, and a thermocompression bonding process.

  The first contact step is a step of bringing the first film into contact with a heating roller whose surface is maintained at a predetermined temperature. The second contact step is a step of bringing the second film into contact with the heating roller through the first film. In the thermocompression bonding step, the first film and the second film are brought into close contact with the heating roller by the tension applied to the second film. This is a step of thermocompression bonding with the film.

  Here, it is preferable that the first contact step and the second contact step are performed simultaneously.

  The heating temperature at the time of lamination and the applied pressure are selected so that thermocompression bonding between the porous films can obtain the desired adhesion strength without impairing the physical properties and characteristics of the porous films. As the temperature at the time of lamination (surface temperature of the heating roller), the resin material contained in the porous film for forming the second layer (in the case of a plurality of types of resin materials, at least one type of resin materials) It is preferable that it is more than the softening point. The temperature at the time of lamination is more preferably lower than or equal to the softening point of the resin material included in the first layer forming film, and is higher than the softening point of the resin material included in the first layer forming film. More preferably, it is low. And the surface temperature of the heating roller 20 in this embodiment is set to a temperature that is 10 to 50 ° C. higher than the softening point of the resin material of the second layer, and a temperature lower than or equal to the softening point of the resin material of the first layer. It is preferable.

  In the present invention, the “softening point” means a melting point in the case of a fiber (resin material) having a melting point, a glass transition point in the case of a fiber (resin material) having a glass transition point without having a melting point, Each shall be indicated.

In the present embodiment, the pressure applied during lamination is controlled by the tension applied to the porous membrane 12. The tension applied to the unwinding side and the winding side with respect to the porous membrane 12 is equal, and this is T. Further, the widths of the porous films 11 and 12 are equal, and this is W. When the radius of the heating roller 20 is R, the pressure P with which the porous film 12 is pressed against the porous film 11 and the heating roller 20 can be defined as the following formula (1).
P = T / (W ・ R) (1)
As shown in the equation (1), the pressure P is constant regardless of the winding angle θ, and the pressure P is uniformly applied to the porous film 12 within the range of the winding angle θ. When the pressure P is too strong, the pressure applied to the porous film 11 increases, and the porous film 11 is crushed, which causes deterioration of the physical properties and characteristics of the film. When the pressure is too weak, the adhesion strength is reduced, and the porous films 11 and 12 are easily peeled off. The tension T applied to the porous membrane 12 needs to be set to an appropriate value in consideration of these. Depending on the material used, the tension can be set so that the pressure is 0.01 to 0.2 kgf / cm ² , for example.

  If the tension applied to the porous membrane 11 is greater than the tension applied to the porous membrane 12, the deformation of the porous membrane 11 itself increases, which causes a deterioration in the physical properties and characteristics of the membrane. In addition, internal stress tends to remain in the porous film 13 after lamination. Therefore, the tension applied to the porous film 11 is preferably equal to or less than the tension applied to the porous film 12.

The winding angle θ affects the heating temperature and pressure application time (hereinafter referred to as lamination time) during lamination. In view of the set temperature and pressure, when the required laminating time is t, between the winding angle θ, the linear velocity V on the surface of the heating roller 20, and the radius R of the heating roller 20, the following equation (2) A relationship is established.
t = (R · θ) / V (2)
It is necessary to design the laminating apparatus so as to ensure the necessary laminating time t based on the formula (2). Although depending on the material used for the porous films 11 and 12, the winding angle can be set such that the laminating time is 1 to 30 seconds, for example. In the example described later, the radius R of the heating roller 20 is 50 mm, the linear velocity V is 6.5 mm / second, and the winding angle can be set between 7.5 and 224 °.

  The process of the laminating method of this invention is demonstrated using FIG.

  The porous film 11 and the porous film 12 fed out under tension are stacked and stacked to form a porous film stack. Subsequently, the laminate is pressed against the heating roller 20 from the exposed surface side of the porous film 11 for forming the first layer, and the entire laminate is heated to a predetermined temperature while passing through the range of the winding angle θ. The Thereby, the porous film 11 for forming the first layer and the porous film 12 for forming the second layer are thermocompression-bonded under pressure by tension. At this time, when the thermal contraction rate of the porous film 11 is larger than that of the porous film 12, the porous film 11 is first brought into contact with the heating roller 20 as shown in FIG. It is also effective to use a path for starting heat shrinkage. The porous film 13 obtained in this way is wound and stored on the winding roller 23.

(Second Embodiment)
Hereinafter, the present invention will be described in detail with reference to a second embodiment of the present invention.

[Laminated porous membrane]
The laminated porous film that is a laminated film manufactured in the second embodiment will be described below.

  In the second embodiment of the present invention described below, the laminated porous film includes a first layer in contact with an image including a liquid and a color material on a recording medium, and a second layer including a second fiber. A laminated porous membrane in which the second layer and the third layer are laminated in this order is obtained. Here, the third layer is a laminated film of the fourth layer including the fourth fibers and the fifth layer including the fifth fibers.

Note that the laminated porous film obtained in the second embodiment is a liquid absorbing member that contacts the image and absorbs at least a part of the first liquid from the image. The laminated porous membrane used as the liquid absorbing member preferably satisfies the following requirements (1) to (5).
(1) The average fiber diameter of the fourth fiber is larger than the average fiber diameter of the fifth fiber.
(2) The second fiber and the fourth fiber have a core-sheath structure having a core structure that forms a central axis and a sheath structure that wraps the core structure.
(3) The softening point of the material forming the sheath structure of the second fiber is greater than the softening point of the material forming the core structure of the second fiber and the softening point of the material forming the first layer. Low.
(4) The softening point of the material forming the sheath structure of the fourth fiber is greater than the softening point of the material forming the core structure of the fourth fiber and the softening point of the material forming the fifth fiber. Low.
(5) The average thickness of the sheath structure of the second fiber is smaller than the thickness of the first layer.
Note that the second layer and the fourth layer may be the same layer as long as the above (1) to (5) are satisfied.

  An example of the porous membrane according to this embodiment is shown in FIG. The porous membrane shown in FIG. 4 includes a first layer 111, a second layer 121 including a second fiber, a fourth layer 131 including a fourth fiber, and a fifth fiber 144. A fifth layer 141. The second fiber has a core-sheath structure having a core structure 122 that forms a central axis and a sheath structure 123 that wraps the core structure 122. The fourth fiber has a core-sheath structure having a core structure 132 that forms the central axis and a sheath structure 133 that wraps the core structure 132. The average fiber diameter d2 ′ of the fourth fiber is larger than the average fiber diameter d3 of the fifth fiber 144. The average thickness t2 of the sheath structure 123 of the second fiber 124 is smaller than the thickness t1 of the first layer 111. Hereinafter, each layer constituting the porous film obtained by the laminating apparatus will be described.

[First layer]
The first layer is a layer that is in contact with an image including a liquid and a color material formed on the recording medium, and is a porous layer that directly touches the image and absorbs at least a part of the liquid in the image. . The material for forming the first layer is not particularly limited, but it is preferable to include a fluororesin having a low surface free energy from the viewpoint of suppressing coloring material adhesion and improving the cleaning property. Further, since the first layer contains the fluororesin, the first porous film is less likely to slip with respect to the heating roller, which will be described later, and the first porous film and the first porous film laminated thereon are rotated with the rotation of the heating roller. 2nd-4th porous membranes can be sent out. Specific examples of the fluororesin are the same as those in the first embodiment.

  From the viewpoint of making the softening point of the material forming the first layer higher than the softening point of the material forming the sheath structure in the second fiber, 170 ° C. or higher is preferable, 180 ° C. or higher is more preferable, and 200 More preferably, it is not lower than ° C. The upper limit of the softening point range of the material forming the first layer is not particularly limited, but can be set to 350 ° C. or lower, for example. In the present invention, the softening point is a value measured by DSC (differential scanning calorimetry). In addition, when the first layer includes a plurality of materials, the softening point in a state including the plurality of materials is shown.

  The average pore diameter on the surface of the first layer in contact with the image is preferably 10.0 μm or less, and preferably 1.0 μm or less, from the viewpoint of suppressing coloring material adhesion when pressed to the image. It is more preferable that the thickness is 0.2 μm or less. In particular, when the average pore diameter is 0.2 μm or less, the filterability is improved, and the coloring material adhesion to the porous film is greatly suppressed. In the present invention, the average pore diameter is an average value obtained by observing the surface of the porous layer with an electron microscope and measuring 20 or more points as the diameter when the area of the pores on the surface is the area of a circle. The lower limit of the average pore diameter range is not particularly limited, but may be, for example, 0.02 μm or more.

  The thickness of the first layer is preferably 50 μm or less, more preferably 30 μm or less, further preferably 10 μm or less, and particularly preferably 5 μm or less. When the thickness is 50 μm or less, an increase in flow resistance can be suppressed, and a defect (image flow) in which part of the liquid in the image is pushed away can be suppressed. Although the minimum of the range of this thickness is not specifically limited, For example, it can be set as 1 micrometer or more. In addition, in this invention, thickness is a value obtained by measuring thickness of arbitrary 10 points | pieces with a straight-ahead type micrometer (brand name: OMV_25, product made by Mitutoyo), and calculating the average value.

[Second layer]
The second layer is a porous layer that adheres to the first layer. The second layer includes a second fiber and may consist of the second fiber. The second layer may be a nonwoven fabric or a woven fabric. The second fiber has a core-sheath structure having a core structure that forms a central axis and a sheath structure that wraps the core structure. The material forming the core structure and the material forming the sheath structure of the second fiber are not particularly limited as long as the softening point relationship in the present embodiment is satisfied, and the same material as that in the first embodiment is used. Can be mentioned.

  The softening point of the material forming the sheath structure of the second fiber is lower than the softening point of the material forming the core structure of the second fiber and the softening point of the material forming the first layer. Thereby, when bonding the first layer and the second layer by heating, only the material forming the sheath structure of the second fiber can be softened by selecting the heating temperature, The core structure of 2 fibers does not melt. Therefore, the shape of the second fiber can be maintained, and crushing of the second layer can be prevented. The softening point of the material forming the sheath structure of the second fiber is 5 ° C. or higher than the softening point of the material forming the core structure of the second fiber and the softening point of the material forming the first layer. It is preferably low and more preferably 10 ° C. or higher.

  The softening point of the material forming the core structure of the second fiber is preferably 140 ° C. or higher, and more preferably 150 ° C. or higher, from the viewpoint of satisfying the softening point relationship in the present embodiment. Although the upper limit of the range of the softening point of the material forming the core structure of the second fiber is not particularly limited, it can be, for example, 180 ° C. or lower. The softening point of the material forming the sheath structure of the second fiber is preferably less than 140 ° C., more preferably 130 ° C. or less, from the viewpoint of satisfying the softening point relationship in the present embodiment. . The lower limit of the softening point of the material forming the sheath structure of the second fiber is not particularly limited, and can be, for example, 110 ° C. or higher.

  The average thickness of the sheath structure of the second fiber is smaller than the thickness of the first layer from the viewpoint of suppressing image flow due to the crushing of the first layer. The average thickness of the sheath structure of the second fibers is preferably 1.0 μm or more and more preferably 2.0 μm or less than the thickness of the first layer. The average thickness of the sheath structure of the second fiber is preferably 0.5 to 5.0 μm, more preferably 1.0 to 3.0 μm, from the viewpoint of satisfying the relationship. Moreover, 1.0-10.0 micrometers is preferable and, as for the average diameter of the core structure of a said 2nd fiber, 2.0-8.0 micrometers is more preferable.

  The average fiber diameter of the second fibers is preferably 1 to 10 μm and more preferably 2 to 8 μm from the viewpoint of suppressing unevenness on the surface of the second layer. The thickness of the second layer is preferably 10 to 500 μm from the viewpoint of transportability.

[Third layer]
The third layer includes a fourth layer and a fifth layer which will be described later. The fourth layer and the fifth layer will be described below.

[Fourth layer]
The fourth layer is a porous layer that is disposed on the second layer side and adheres to the second layer. The fourth layer includes a fourth fiber and may consist of the fourth fiber. The fourth layer may be a nonwoven fabric or a woven fabric. The fourth fiber has a core-sheath structure having a core structure that forms a central axis and a sheath structure that wraps the core structure. The material for forming the core structure and the material for forming the sheath structure of the fourth fiber is not particularly limited as long as the softening point relationship in the present embodiment is satisfied, and the same material as the second fiber is used. Can be used.

  The softening point of the material forming the sheath structure of the fourth fiber is lower than the softening point of the material forming the core structure of the fourth fiber and the softening point of the material forming the fourth fiber. Thereby, when the fourth layer and the fifth layer are bonded by heating, only the material forming the sheath structure of the fourth fiber can be softened by selecting the heating temperature, The fiber core structure of 4 does not melt. Therefore, the shape of the fourth fiber can be maintained, and crushing of the fourth layer can be prevented. The softening point of the material forming the sheath structure of the fourth fiber is lower by 5 ° C. than the softening point of the material forming the core structure of the fourth fiber and the softening of the material forming the fifth layer. It is preferable that the temperature is lower by 10 ° C. or more.

  The softening point of the material forming the core structure of the fourth fiber is preferably 140 ° C. or higher, and more preferably 150 ° C. or higher, from the viewpoint of satisfying the softening point relationship in the present embodiment. The upper limit of the range of the softening point of the material forming the core structure of the fourth fiber is not particularly limited, and can be, for example, 180 ° C. or lower. The softening point of the material forming the sheath structure of the fourth fiber is preferably less than 140 ° C., more preferably 130 ° C. or less, from the viewpoint of satisfying the softening point relationship in the present embodiment. . The lower limit of the softening point range of the material forming the sheath structure of the fourth fiber is not particularly limited, and can be, for example, 110 ° C. or higher.

  The average thickness of the sheath structure of the fourth fiber is preferably 0.5 to 5.0 μm, and more preferably 1.0 to 4.0 μm. The average diameter of the fourth fiber core structure is preferably 1.0 to 30.0 μm, and more preferably 5.0 to 20.0 μm.

  The average fiber diameter of the fourth fiber is larger than the average fiber diameter of the fifth fiber from the viewpoint of improving the adhesive strength between the fourth layer and the fifth layer. The average fiber diameter of the fourth fibers is preferably 1 μm or more and more preferably 2 μm or more larger than the average fiber diameter of the fifth fibers. The average fiber diameter of the fourth fibers is preferably 10 to 50 μm, more preferably 15 to 30 μm, from the viewpoint of satisfying the relationship. The thickness of the fourth layer is preferably 10 to 500 μm from the viewpoint of transportability.

[Fifth layer]
The fifth layer is a porous layer that increases the rigidity of the liquid absorbing member. The fifth layer includes fifth fibers and may consist of fifth fibers. The fifth layer may be a nonwoven fabric or a woven fabric. The material forming the fifth fiber is not particularly limited as long as it satisfies the softening point relationship in the present invention, and examples thereof include polyphenylene sulfide (PPS), polyimide, and polyethylene terephthalate (PET). These may use 1 type and may use 2 or more types together. However, from the viewpoint of improving the transport strength, the fifth fiber preferably contains polyphenylene sulfide (PPS) or polyimide.

  The softening point of the material forming the fifth fiber is preferably 150 ° C. or higher, more preferably 170 ° C. or higher, and more preferably 200 ° C. or higher from the viewpoint of satisfying the softening point relationship in the present invention. preferable. Although the upper limit of the softening point range of the material forming the fifth fiber is not particularly limited, it can be, for example, 350 ° C. or lower.

  The thickness of the fifth layer is preferably 50 to 500 μm, more preferably 100 to 400 μm, and still more preferably 150 to 300 μm, from the viewpoint of increasing the conveyance strength and ensuring the rigidity. The average fiber diameter of the fifth fiber is preferably 2 to 15 μm and more preferably 5 to 10 μm from the viewpoint of making the average fiber diameter smaller than the average fiber diameter of the fourth fiber.

[Laminating apparatus and laminated film manufacturing method]
A laminating apparatus and a method for manufacturing a laminated film in the second embodiment of the present invention will be described.

  In order to manufacture the porous film in the second embodiment, it is preferable to perform lamination in two stages. Specifically, in the first-stage lamination, a laminated film (first film) corresponding to a third layer having a fourth layer-forming porous film 231 and a fifth layer-forming porous film 241. 3) is manufactured in advance. In the second-stage lamination, the laminated film (third film) obtained by the first-stage lamination, the porous film 221 (second film) for forming the second layer, and the first layer formation are formed. A laminated film with the porous film 211 (first film) is manufactured. The laminating apparatus and laminated film manufacturing method used in each of the first-stage and second-stage laminates will be described.

<First stage laminator>
FIG. 5 is a schematic view of a laminating apparatus 7 that forms a laminated film (third film) by thermocompression bonding a porous film 231 for forming a fourth layer and a porous film 241 for forming a fifth layer. It is. The laminating apparatus 7 is a conventional nip roller type apparatus that sandwiches and laminates a base material while a pair of heating rollers rotate.

  The laminating apparatus 7 includes unwinding rollers 361, 362, 365, heating rollers 360, 364, winding rollers 363, 366, and rollers 371-376. An air clutch (not shown) is attached to the unwinding roller 361, and the protective sheet 161 is unwound from the set roll 161R with a constant tension. An air clutch (not shown) is attached to the unwinding roller 362, and the porous film 231 for forming the fourth layer is unwound at a constant tension from the set roll 231R. Further, an air clutch (not shown) is attached to the unwinding roller 365, and the porous film 241 for forming the fifth layer is unwound at a constant tension from the set roll 241R. In this embodiment, a tension control method using an air clutch is adopted in unwinding, but the control method is not limited to this, and a feedback method using a tension detection sensor or a dancer roller may be used.

  The heating roller 360 includes a heat source inside, and can maintain the surface covered with metal in a predetermined temperature range. The heating roller 364 also has a heat source inside, and the surface covered with heat-resistant rubber can be maintained in a predetermined temperature range. The type of each heat source is not particularly limited, but an electric heating method, a dielectric heating method, or the like may be used. A motor (not shown) is attached to each of the heating rollers 360 and 364, and the heating rollers 360 and 364 rotate synchronously so that their tangential speeds are the same. The heating roller 364 includes an up / down mechanism using an air cylinder, and can be pressed against the heating roller 360 with a predetermined pressure.

  An air clutch is attached to the winding roller 363, and the two-layer porous film 151 corresponding to the third layer obtained by laminating the fourth layer and the fifth layer is fixed to the roll 151R with a certain tension. Wind up with. An air clutch is attached to the winding roller 366 and winds the protective sheet 161 with a constant tension. In this embodiment, a tension control method using an air clutch is adopted in winding, but the control method is not limited to this, and a feedback method using a tension detection sensor or a dancer roller may be used.

<Method for Manufacturing First Layer Laminated Film (Third Film)>
A method of manufacturing the two-layer porous film 151 that is a laminated film using the laminating apparatus 7 will be described.

  The heating temperature at the time of lamination and the applied pressure are selected so that thermocompression bonding between the porous films can obtain the desired adhesion strength without impairing the physical properties and characteristics of the porous films.

  The temperature of the heating rollers 360 and 364 when laminating the fourth layer-forming porous membrane 231 and the fifth layer-forming porous membrane 241 depends on the material that forms the sheath structure of the fourth fiber. Above the softening point. Furthermore, the softening point of the material forming the core structure of the fourth fiber is less than the softening point of the material forming the fourth fiber. Thereby, since only the material which forms the said sheath structure can be softened and the core structure is not melted, the shape of the fourth fiber can be maintained. Accordingly, since the entire fourth layer is not melted, the fourth layer can be prevented from being crushed. Although the temperature of the said heating is based also on the material to be used, it can be 100-160 degreeC, for example.

  When the material of the sheath structure of the fourth layer is melted by heating, the protective sheet 161 is used to prevent the material from adhering to the heating roller. The material of the protective sheet 161 is preferably a material that is heat resistant to the heating temperature, has good thermal conductivity, and does not adhere to the sheath material of the fourth layer. For example, a polyimide film, a PET film, or a PPS film can be used. Further, since the melted material does not adhere to the heating roller, the width dimension of the protective sheet 161 in the direction perpendicular to the transport direction is preferably wider than the width dimension of the porous film 231 for forming the fourth layer. .

The nip pressure of the pair of heating rollers 360 and 364 when laminating the porous film 231 for forming the fourth layer and the porous film 241 for forming the fifth layer is that of the sheath structure of the molten fourth layer. It is desirable that the material be at or above the pressure at which the material adheres to the fifth layer of fibers. Further, the nip pressure is preferably not more than a pressure at which the core structure of the fourth layer is not deformed in order to prevent crushing. Although the said nip pressure is based on the material to be used, it can be set to 0.5-5 kgf / cm < ² >, for example.

  By the laminating apparatus 7 and its manufacturing method described above, the fourth layer forming porous film 231 and the fifth layer forming porous film 241 are laminated to form the fourth layer and the fifth layer. A two-layer porous membrane 151 corresponding to the third layer can be manufactured.

<Second stage laminator>
FIG. 6 shows a porous film (first film) 211 for forming a first layer, a porous film (second film) 221 for forming a second layer, and the two-layer porous film (first film). 3 is a schematic view of a laminating apparatus 9 that forms a laminated film by thermocompression bonding.

  The laminating apparatus 9 includes unwinding rollers 321, 322, and 325, a heating roller 320, a winding roller 323, and rollers 331 to 335. An air clutch (not shown) is attached to the unwinding roller 321 (first tension applying means or first roller), and the porous film 211 for forming the first layer is removed from the set roll 211R. Unwind with constant tension. An air clutch (not shown) is attached to the unwinding roller 322 (second tension applying means or the second roller), and the porous film 221 for forming the second layer is removed from the set roll 221R. Unwind with constant tension. Further, an air clutch (not shown) is attached to the unwinding roller 325 (the fourth tension applying means or the fourth roller), and the two-layer porous membrane 151 is moved from the set roll 151R with a constant tension. Unwind. In this embodiment, a tension control method using an air clutch is adopted in unwinding, but the control method is not limited to this, and a feedback method using a tension detection sensor or a dancer roller may be used.

  The heating roller 320 includes a heat source therein, and can maintain the surface covered with metal in a predetermined temperature range. The type of the 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 320 and can rotate at a predetermined speed.

  An air clutch (not shown) is attached to the winding roller 323 (the third tension applying means or the third roller), and the porous films 211 and 221 and the two-layer porous film 151 are laminated. The obtained laminated porous film 101 is wound around the roll 101R with a constant tension. In this embodiment, a tension control method using an air clutch is adopted in winding, but the control method is not limited to this, and a feedback method using a tension detection sensor or a dancer roller may be used.

  In this embodiment, a motor, which is a driving source for continuously conveying the porous film, is attached to the heating roller 320, but the present invention is not limited to this. The heating roller may be in an unloaded state, and a method of feeding the laminated porous film 113 through a nip on the downstream side of the heating roller or a method of attaching a motor to the winding roller 323 may be used.

  A configuration around the heating roller 320 as a feature of the present invention will be described with reference to FIG.

  FIG. 7A is an enlarged view around the heating roller of FIG. The porous film 211 that is the first film, the porous film 221 that is the second film, and the two-layer porous film 151 that is the third film are conveyed so as to form a path wound around the heating roller 320. Is done. At this time, the winding angle starting from the point at which the two-layer porous film 151 starts to contact the heating roller 320 via the porous films 211 and 221 and ending at the point starting to separate is defined as θ. This winding angle θ is larger than 0 °. At this time, the rollers 333 and 335 are arranged so that the winding angle θ becomes a predetermined angle (see FIG. 6). As described above, the porous films 211, 221, and the two-layer porous film 151 are each in tension, and are in close contact with the heating roller 320 within the range of the winding angle θ.

  As the heating roller 320 is rotated by a motor (not shown), the porous film 211 is fed at a predetermined speed by friction between the heating roller 320 and the porous film 211. In addition, the porous film 211, the porous film 221 and the two-layered porous film 151 are laminated between the winding angles θ and sent by adhesion between the layers.

  A method for producing a four-layer laminated porous membrane 101 using the laminating apparatus 9 will be described. The heating temperature at the time of lamination and the applied pressure are selected so that thermocompression bonding between the porous films can obtain the desired adhesion strength without impairing the physical properties and characteristics of the porous films.

  The temperature of the heating roller at the time of lamination is not less than the softening point of the material forming the sheath structure of the second fiber and the fourth fiber, and the core structure of the second fiber and the fourth fiber. Less than the softening point of the material forming the. And it is below the softening point of the material which forms the said 1st fiber, and below the softening point of the material which forms the said 5th fiber. Thereby, since only the material which forms the said sheath structure can be softened and the core structure is not melted, the shapes of the second fiber and the fourth fiber can be maintained. Therefore, since the second layer and the entire fourth layer are not melted, it is possible to prevent the second layer and the fourth layer from being crushed. Although the temperature of the said heating is based also on the material to be used, it can be 100-160 degreeC, for example.

  FIG. 7B is a cross-sectional view of the region E in FIG. 7A viewed from the direction Y (that is, the direction perpendicular to the peripheral surface of the heating roller). By disposing the porous film 211 for forming the first layer between the heating roller 320 and the porous film 221 for forming the second layer, the sheath of the second layer and the fourth layer is heated. When the material of the structure is melted, the material can be prevented from adhering to the heating roller. Therefore, at least within the range of the winding angle θ of the heating roller 320, the width dimension w1 of the porous film 211 is the width of the porous film 221 for forming the second layer and the porous film 231 for forming the fourth layer. It is preferable that it is wider than the dimensions w2 and w3. If it is difficult to realize the relationship between the width dimensions, the surface of the heating roller 320 can be protected to prevent the melted sheath material of the second layer and the fourth layer from adhering. . The width dimension means the dimension in the axial direction of the heating roller.

<Manufacturing method of second layer laminated film>
A method for manufacturing the laminated porous film 101 using the laminating apparatus 9 will be described.

The pressure applied during lamination is controlled by the tension applied to the two-layer porous membrane 151. The relationship between the tension, the width of the porous film, the radius of the heating roller, and the pressure is as shown in the above formula (1). In the present embodiment, the width W of the porous film is defined as the width of the narrowest film among the first, second, fourth, and fifth porous films. If the pressure is too strong, the porous membrane 211 and the porous membrane 221 are crushed, which causes the physical properties and characteristics of the membrane to deteriorate. When the pressure is too weak, the adhesion strength is reduced, and the porous 211 and the porous film 221 are easily peeled off from the two-layer porous film 151. The tension of the porous membrane 151 needs to be set to an appropriate value in consideration of these. Depending on the material used, the tension can be set so that the pressure is 0.01 to 0.2 kgf / cm ² , for example.

  The winding angle θ is set so as to ensure an appropriate laminating time. The relationship between the winding angle, the linear velocity on the surface of the heating roller, the radius of the heating roller, and the laminating time is as shown in the formula (2). Although depending on the material used, the winding angle can be set so that the laminating time is 1 to 30 seconds, for example. In the example described later, the radius R of the heating roller 20 is 125 mm, the linear velocity V is 8.2 mm / second, and the winding angle can be set between 4 and 113 °.

The first layer forming porous film 211, the second layer forming porous film 221 and the two-layered porous film 151 are laminated by the laminating apparatus 9 and the manufacturing method described above, and the first layer is formed. The laminated porous membrane 101 composed of the second layer, the fourth layer, and the fifth layer can be manufactured.
The laminating apparatuses 7 and 9 described above are apparatuses for manufacturing a four-layered porous film composed of a first layer, a second layer, a fourth layer, and a fifth layer. When manufacturing a three-layer laminated porous film having a structure in which the second layer and the fourth layer are the same layer (second layer), the laminating apparatuses 7 and 1 may be used. At that time, first, the porous film 221 for forming the second layer is set on the unwinding roller 362 of the laminating apparatus 7. Further, the porous film 241 for forming the fifth layer is set on the unwinding roller 365. Then, a two-layer porous film 152 obtained by laminating the porous films 221 and 241 is created. Next, in the laminating apparatus 1, the porous film 211 for forming the first layer is set on the unwinding roller 21, and the two-layer porous film 152 is set on the unwinding roller 22. By laminating the porous membrane 152, a three-layer laminated porous membrane can be created.

  In the present embodiment, the two-stage lamination is performed using the two laminating apparatuses 7 and 9, but one apparatus may be used. For example, as shown in FIG. 8, there is a laminating apparatus 3 having a configuration in which laminating apparatuses 7 and 9 are integrated. The laminating apparatus 3 includes unwinding rollers 421 to 425, winding rollers 451 and 452, rollers 401 to 411, heating rollers 460 to 462, dancer rollers 431 and 432, nip rollers 441 and 442, and a buffer roller 455. The protective sheet 161 is pulled out from the unwinding roller 421, the porous film 231 for forming the fourth layer is pulled out from the unwinding roller 422, and the porous film 241 for forming the fifth layer is pulled out from the unwinding roller 423. Further, the porous film 211 for forming the first layer is unwound from the unwinding roller 424, and the porous film 221 for forming the second layer is unwound from the unwinding roller 425. The pair of heating rollers 460 and 461 performs the first-stage lamination, and the heating roller 462 performs the second-stage lamination. As a tension control of the two-layer porous film 151 on the downstream side of the heating roller 460 and the upstream side of the heating roller 462, a system using a dancer roller and a servo-driven nip roller is used. In order to cope with the deviation of the conveyance speed between the nip rollers, a buffer roller that can freely move up and down according to the deviation is provided. The manufacturing method of the laminated porous film using the laminating apparatus 3 having these configurations is the same as that of the embodiment described above.

In this embodiment, a conventional nip roller type laminate is adopted as the first-stage laminate, but the lamination method is not limited to this. In the first-stage lamination, in order to laminate the fourth layer forming porous film and the fifth layer forming porous film, it is necessary to satisfy the following (1) and (2).
(1) A temperature not lower than the softening point of the material forming the sheath structure of the fourth fiber and not higher than the softening point of the material forming the core structure of the fourth fiber and the softening point of the material forming the fifth fiber. Give.
(2) A pressure equal to or lower than a pressure at which the fourth fiber is crushed and a pressure equal to or higher than a pressure at which the melted sheath material of the fourth fiber penetrates the fifth fiber is applied.

  If these conditions (1) and (2) are satisfied, the same method as the second-stage lamination of the present invention can be used as the first-stage lamination method, or a method of sandwiching with a hot plate is used. You can also. In the second-stage laminate, the following (3) and (4) must be satisfied.

(3) The softening point of the material forming the sheath structure of the second fiber and the fourth fiber, the softening point of the material forming the core structure of the second fiber and the fourth fiber, and the first fiber A temperature equal to or lower than the softening point of the material to be formed and the softening point of the material to form the fifth fiber is applied.
(4) A pressure equal to or lower than a pressure at which the first fiber, the second fiber, and the fourth fiber are crushed and a pressure equal to or higher than a pressure at which a melted sheath material of the second fiber penetrates the first fiber is applied. To do.

If these conditions (3) and (4) are satisfied, the second-stage laminate is not limited to the method of the present invention. However, in this embodiment, it is preferable that the first fiber material includes a fluororesin as described above, and the first fiber is easily deformed by including the fluororesin. Therefore, the pressure at which the first fibers in the above (3) are crushed is lower than the pressure at which the second fibers and the fourth fibers are crushed. In order not to be crushed, for example, 0.2 kgf / cm ² or less is preferable. In the conventional nip roller system, in order to stably apply pressure in this range, a mechanism for controlling the relative position of the pair of heating rolls with high accuracy is required, and the apparatus becomes complicated. On the other hand, with the laminating method of the present invention, it is possible to realize the application of pressure within the above range without such a mechanism, and it is possible to reduce the cost of the apparatus and stabilize the process.

  Hereinafter, the first embodiment of the present invention will be described in more detail using examples and comparative examples. The present invention is not limited in any way by the following examples as long as the gist thereof is not exceeded.

(Examples 1 and 2)
First, the porous film used in Examples 1 and 2 corresponding to the first embodiment will be described.

  The porous film 11 for forming the first layer is made of PTFE (softening point 320 ° C.), a film thickness of 40 μm, and a width of 100 mm. The porous film 12 for forming the second layer is made of polyethylene (softening point 150 ° C.), film thickness 130 μm, width 100 mm. In addition, the thickness of the porous film of each layer of the porous film is measured by measuring the layer thickness at any 10 points with a straight-forward micrometer OMV_25 (manufactured by Mitutoyo), and calculating the average value as the thickness of the porous film did.

  Next, design conditions for the laminating apparatus in Examples 1 and 2 will be described. The basic configuration is as shown in FIG. 1. The heating roller 20 has a radius R of 50 mm and a winding angle θ of 75 °. The linear velocity V on the surface of the heating roller 20 was 6.5 mm / second, that is, the lamination time t was 10 seconds. The tension applied to the porous membrane 11 was fixed at 0.5N.

  Lamination was performed under the conditions shown in Table 1 by changing the tension T applied to the porous film 12 and the temperature of the heating roller 20.

(Comparative Example 1)
In Comparative Example 1, as shown in Table 1, lamination was performed in the same manner as in Example 1 except that the tension applied to the porous membrane 12 was changed.

(Comparative Examples 2 and 3)
As Comparative Examples 2 and 3, using the conventional nip roller system shown in FIG. 3 instead of the laminating apparatus shown in FIG. Lamination was performed. 3 includes unwinding rollers 61 and 62, heating rollers 60 and 64, a winding roller 63, and rollers 71, 72, and 73. Further, 51R, 52R, and 53R are rolls, 51 is a first porous film, 52 is a second porous film, and 53 is a laminated porous film. Further, the heating roller 64 presses against the heating roller 60.

[Evaluation]
The porous film obtained above was evaluated by the following evaluation method. Specifically, the air permeability of the porous film is evaluated in order to confirm the presence or absence of deformation of the porous film, and the adhesion strength of the porous film is evaluated in order to confirm the state of bonding between the films. Went. The evaluation results are shown in Table 3.

<Breathability>
The air permeability can be defined by a Gurley value measured by a Gurley tester defined in JIS P8117. The Gurley value of the entire porous membrane obtained by the production method of the present invention is preferably 10 seconds or less. Therefore, the evaluation criteria in Table 3 are as follows.
○: Gurley value was 10 seconds or less.
X: Gurley value was greater than 10 seconds.

<Adhesion strength>
In the method defined in the 90 degree peel test method defined in JIS Z0237, it is necessary to be larger than 1 N / 20 mm. Therefore, the evaluation criteria in Table 3 are as follows.
A: The adhesion strength was 5 N / 20 mm or more.
B: The adhesion strength was greater than 1 N / 20 mm and less than 5 N / 20 mm.
C: The adhesion strength was 1 N / 20 mm or less.

  Hereinafter, the second embodiment of the present invention will be described in more detail using examples and comparative examples. The present invention is not limited in any way by the following examples as long as the gist thereof is not exceeded.

(Examples 3 and 4)
The laminated porous membrane used in Examples 3 and 4 will be described. The porous film 211 for forming the first layer is made of PTFE (softening point 320 ° C.), a film thickness of 2 μm, and a width of 1000 mm. The porous film 221 for forming the second layer has a core structure material of polypropylene (softening point 160 ° C.), a sheath structure material of polyethylene (softening point 130 ° C.), a film thickness of 70 μm, and a width of 850 mm. The porous film 231 for forming the fourth layer has a core structure material of polypropylene (softening point 160 ° C.), a sheath structure material of polyethylene (softening point 130 ° C.), a film thickness of 50 μm, and a width of 850 mm. The fifth layer-forming porous membrane 241 is made of polyphenylene sulfide (softening point 260 ° C.), a thickness of 210 μm, and a width of 1000 mm. In addition, the thickness of the porous film of each layer of the porous film is measured by measuring the layer thickness at any 10 points with a straight-forward micrometer OMV_25 (manufactured by Mitutoyo), and calculating the average value as the thickness of the porous film. did.

  Next, setting conditions of the laminating apparatus 9 in Examples 3 and 4 will be described. The basic configuration is as shown in FIG. 6. The radius R of the heating roller 320 is 125 mm and the winding angle θ is 30 °. The linear velocity V on the surface of the heating roller 320 was 8.2 mm / second, that is, the lamination time t was 8 seconds. The tension applied to the porous membrane 211 was fixed to 1.5N, and the tension applied to the porous membrane 221 was fixed to 15N.

  Lamination was performed under the conditions shown in Table 4 by changing the tension T applied to the porous film 151 and the temperature of the heating roller 320.

(Comparative Example 4)
In Comparative Example 4, as described in Table 4, lamination was performed in the same manner as in Example 3 except that the temperature of the heating roller 320 was changed.

(Comparative Examples 5 and 6)
Also in the second-stage lamination, comparative examples 5 and 6 are obtained by performing lamination under the conditions shown in Table 5 using the nip roller type laminating apparatus 7 shown in FIG.

[Evaluation]
As an evaluation of the porous membrane obtained above, the breathability and adhesion strength were measured in the same manner as in Examples 1 and 2. The evaluation method and evaluation criteria are also the same as in Examples 1 and 2. The evaluation results are shown in Table 6.

DESCRIPTION OF SYMBOLS 1 Laminating apparatus 11 1st porous film 12 2nd porous film 13 Laminated porous film 20 Heating roller

Claims (21)

A laminated film having a first layer formed by the first film and a second layer formed by the second film by thermocompression bonding the first film and the second film A laminating device for forming
A heating roller capable of maintaining the surface at a predetermined temperature;
First tension applying means for applying tension to the first film;
Second tension applying means for applying tension to the second film;
A third tension applying means for applying tension to the laminated film obtained by laminating the first film and the second film;
The first film and the second film are closely attached to one heating roller so as to be laminated in this order, and the winding angle of the first film and the second film is 0. A laminating apparatus configured to be larger than °.   The laminating apparatus according to claim 1, wherein each of the first film and the second film is a porous film.   The laminating apparatus according to claim 1 or 2, wherein a surface temperature of the heating roller is lower than a softening point of a material included in the first film.   The width dimension of the first film is larger than the width dimension of the second film when the dimension in the axial direction of the heating roller is defined as a width dimension. The laminating apparatus described in 1.   The laminating apparatus according to any one of claims 1 to 4, wherein a surface temperature of the heating roller is equal to or higher than a softening point of a material included in the second film. The second film is a film formed by second fibers;
The second fiber has a core-sheath structure having a core structure that forms a central axis and a sheath structure that wraps the core structure;
The softening point of the material forming the sheath structure of the second fiber is lower than the softening point of the material forming the core structure of the second fiber. The laminating apparatus described in 1.   The surface temperature of the heating roller is lower than the softening point of the material forming the core structure of the second fiber, and is equal to or higher than the softening point of the material forming the sheath structure of the second fiber. The laminating apparatus according to claim 6. The laminated film further includes a third layer formed by a third film,
The laminating apparatus further includes a fourth tension applying unit for applying tension to the third film,
The third tension applying means is tension means for applying tension to a laminated film obtained by laminating the first film, the second film, and the third film,
The first film, the second film, and the third film are closely attached to one heating roller so as to be laminated in this order, and the first film, the second film, The laminating apparatus according to any one of claims 1 to 7, wherein a winding angle of the film and the third film is configured to be larger than 0 °.   The laminating apparatus according to claim 8, wherein the third film has a fourth layer and a fifth layer. A laminated film having a first layer formed by the first film and a second layer formed by the second film by thermocompression bonding the first film and the second film A laminating device for forming
A heating roller capable of maintaining the surface at a predetermined temperature;
A first roller around which the first film is wound;
A second roller around which the second film is wound;
A third roller around which the laminated film is wound,
Tension is applied to the first film by the first roller, the third roller, and the heating roller,
Tension is applied to the second film by the second roller, the third roller, and the heating roller,
The first film and the second film are closely attached to one heating roller so as to be laminated in this order, and the winding angle of the first film and the second film is 0. A laminating apparatus configured to be larger than °. A laminated film having a first layer formed by the first film and a second layer formed by the second film by thermocompression bonding the first film and the second film A method for producing a laminated film for forming
A first contact step of bringing the first film into contact with a heating roller whose surface is maintained at a predetermined temperature;
A second contact step in which the second film is brought into contact with the heating roller via the first film;
The first film and the second film are thermocompression-bonded by bringing the second film and the first film into close contact with the heating roller by the tension applied to the second film. A thermocompression bonding process;
A method for producing a laminated film, comprising:   The method for producing a laminated film according to claim 11, wherein a winding angle of the first film and the second film with respect to the heating roller in the thermocompression bonding step is larger than 0 °.   The method for producing a laminated film according to claim 11 or 12, wherein each of the first film and the second film is a porous film.   The method for manufacturing a laminated film according to claim 11, wherein the first contact step and the second contact step are performed simultaneously.   The method for producing a laminated film according to any one of claims 11 to 14, wherein a surface temperature of the heating roller is lower than a softening point of a material included in the first film.   16. The width dimension of the first film is larger than the width dimension of the second film when the dimension in the axial direction of the heating roller is defined as a width dimension. The manufacturing method of laminated film as described in any one of.   The method for producing a laminated film according to claim 11, wherein a surface temperature of the heating roller is equal to or higher than a softening point of a material included in the second film. The second film is a film formed by second fibers;
The second fiber has a core-sheath structure having a core structure that forms a central axis and a sheath structure that wraps the core structure;
17. The softening point of the material forming the sheath structure of the second fiber is lower than the softening point of the material forming the core structure of the second fiber. The manufacturing method of laminated film as described in any one of.   The surface temperature of the heating roller is lower than the softening point of the material forming the core structure of the second fiber, and is equal to or higher than the softening point of the material forming the sheath structure of the second fiber. The manufacturing method of the laminated film of Claim 18. A first film formed by the first film and a second film formed by the second film are formed by thermocompression bonding the first film, the second film, and the third film. A method for producing a laminated film, comprising: forming a laminated film having a layer and a third layer formed by the third film,
A first contact step of bringing the first film into contact with a heating roller whose surface is maintained at a predetermined temperature;
A second contact step in which the second film is brought into contact with the heating roller via the first film;
A third contact step of bringing the third film into contact with the heating roller via the first film and the second film;
By bringing the third film, the second film, and the first film into close contact with the heating roller by the tension applied to the third film, the first film and the second film A thermocompression bonding step of thermocompression bonding the film and the third film;
A method for producing a laminated film, comprising: 21. The method of manufacturing a laminated film according to claim 20, wherein the third film has a fourth layer and a fifth layer.

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