WO2014171365A1

WO2014171365A1 - Method for manufacturing thermoplastic film

Info

Publication number: WO2014171365A1
Application number: PCT/JP2014/060166
Authority: WO
Inventors: 箕浦潔; 森岡聡子; 廣藤誠
Original assignee: 東レ株式会社
Priority date: 2013-04-18
Filing date: 2014-04-08
Publication date: 2014-10-23
Also published as: TWI624370B; TW201446517A; CN105121114B; JP6380102B2; CN105121114A; JPWO2014171365A1

Abstract

In the present invention, with respect to a laminated structural body wherein at least an A-layer mainly formed of a thermoplastic resin (P1) having a melting point (Tm1), and a B-layer mainly formed of a thermoplastic resin (P2) having a glass-transition temperature (Tg2) are formed, a molding die having a protruding structure on the surface is pressed to the A-layer side of the laminated structural body, in a state wherein the molding die is heated to a temperature equal to or higher than a higher one of the temperature (Tm1) and the temperature (Tg2), thereby forming through holes, which are disposed at desired positions and density distribution in the A-layer, and which have desired shapes.

Description

Method for producing thermoplastic film

The present invention relates to a method for producing a thermoplastic film having a through hole. The film having through-holes obtained by this method should be used as a member that requires micron-sized to nano-sized through-holes having functions such as filtration, cell culture, cell separation, gas permeation, and moisture permeability. Can do. In such applications, a thermoplastic film having through-holes whose hole shape and arrangement are controlled with high accuracy is particularly preferably used for the purpose of improving performance.

As a method for producing a thermoplastic film having a through-hole in which the shape and arrangement of the holes are controlled with high accuracy, injection molding, electron beam processing on the film, etching, thermal imprinting and the like can be mentioned. In injection molding, a film having through holes can be formed by filling a molten resin into a mold in which protrusions are formed. In the electron beam processing, through holes can be formed by applying an electron beam to the film surface and melting it from the surface toward the inside. In etching, a through-hole is formed by chemically or physically removing the resin by bringing an etching material made of gas or liquid into contact with an opening other than a region shielded by a mask on the film surface. Can be formed.

Patent Documents 1 and 2 disclose a thermal imprint technique in which a through-hole is formed in a film by pressing a mold having a heated projection structure on the surface of the thermoplastic film. Furthermore, as means for improving the through hole molding accuracy, by applying a molten resin to the surface of the mold having protrusions formed on the surface, and then cooling the mold while applying pressure with a pressure plate. A method for producing a film having through holes is disclosed.

JP 2010-154852 A JP 2013-30605 A JP 2011-230396 A

In injection molding, it is difficult to make the film thinner or make the through holes finer. In addition, there is a problem that productivity is low because a process of filling and taking out a resin from a mold is necessary, and processing into a roll-to-roll film is impossible. In addition, since electron beam processing requires a great amount of processing time, there is a problem that productivity is low and mass production is difficult. In addition, there is a problem that it is difficult to form a uniform hole diameter in the depth direction by etching. Furthermore, with the imprint technique disclosed in Patent Document 1 and Patent Document 2, it is difficult to form a through hole with few burrs on the end face of the opening. The reason is that the resin deformation is governed by the viscoelastic properties and is not suitable for plastic deformation that opens a hole. The manufacturing method based on the melt transfer technique disclosed in Patent Document 3 requires the steps of applying a resin to the mold, heating and cooling the mold, and taking out the product, and does not require processing into a roll-to-roll film. There is a problem that productivity is low because it is possible.

In order to solve the above problems, the present invention provides the following method for producing a thermoplastic film.
(1) A protruding structure is provided on the surface of a laminated structure in which an A layer containing a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2 are laminated. The mold is heated to a temperature of Tm1 or more and Tg2 or more and pressed against the A layer side of the laminated structure, thereby forming a through hole in the A layer and forming a recess communicating with the through hole in the B layer. A method for producing a thermoplastic film, comprising:
(2) A protruding structure is provided on the surface of the laminated structure in which the A layer containing the thermoplastic resin P1 having the melting point Tm1 and the B layer containing the thermoplastic resin P2 having the glass transition temperature Tg2 are laminated. The mold is heated to a temperature of Tm1 or more and Tg2 or more and pressed against the A layer side of the laminated structure, thereby forming a through hole in the A layer and forming a recess communicating with the through hole in the B layer. Then, after that, the A layer and the B layer are peeled off to obtain a thermoplastic film having a through hole including the A layer.
(3) The method for producing a thermoplastic film according to (1) or (2), wherein a difference (Tm1−Tg2) between the melting point Tm1 and the glass transition temperature Tg2 is −30 to 60 ° C.
(4) The method for producing a thermoplastic film according to (3), wherein a difference (Tm1−Tg2) between the melting point Tm1 and the glass transition temperature Tg2 is −10 to 0 ° C.
(5) The method for producing a thermoplastic film as described in any one of (1) to (4), wherein the thermoplastic resin P1 is polyethylene or polypropylene.
(6) The method for producing a thermoplastic film according to any one of (1) to (5), wherein the thermoplastic resin P2 is polymethyl methacrylate or polycarbonate.
(7) The method for producing a thermoplastic film according to any one of (1) to (6), wherein the diameter of the through hole is 1 to 100 μm.
(8) The method for producing a thermoplastic film according to any one of (1) to (7), wherein the thickness of the A layer is 5 to 50 μm.
(9) The method for producing a thermoplastic film according to any one of (1) to (8), wherein the protrusion structure is a structure in which a weight shape and a columnar shape are connected.

According to the present invention, a protruding structure is formed on a laminated structure in which an A layer containing a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2 are laminated. The mold on the surface is heated to a temperature of Tm1 or more and Tg2 or more, and pressed against the A layer side of the laminated structure, thereby being disposed in the A layer at a desired position and density distribution and having a desired shape Holes can be formed.

It is the flowchart which showed an example of the embodiment concerning the manufacturing method of the thermoplastic film which has a through-hole of this invention. It is the flowchart which showed an example of the embodiment concerning the manufacturing method of the thermoplastic film which has a through-hole of this invention. It is a perspective view which shows an example of the metal mold | die applied to the manufacturing method of this invention. It is sectional drawing which shows an example of the metal mold | die applied to this invention. It is a section schematic diagram showing an example of a device which realizes a manufacturing method of a film which has a penetration hole of the present invention. It is a section schematic diagram showing an example of a device which realizes a manufacturing method of a film which has a penetration hole of the present invention. 2 is a surface photograph of a film produced by the production method of the present invention described in Example 1 using a scanning electron microscope. 2 is a cross-sectional photograph of a film produced by the production method of the present invention described in Example 1 using a scanning electron microscope. 2 is a surface photograph of a film produced by the production method of the present invention described in Example 2 using a scanning electron microscope. 3 is a cross-sectional photograph taken by a scanning electron microscope of a film produced by the production method of the present invention described in Example 2. FIG. 2 is a surface photograph of a film produced by the production method of the present invention described in Comparative Example 1 using a scanning electron microscope. 2 is a cross-sectional photograph of a film produced by the production method of the present invention described in Comparative Example 1 using a scanning electron microscope.

The present invention relates to a method for producing a thermoplastic film having a through hole.

One of the production methods according to the present invention is for a laminated structure in which an A layer containing a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2 are laminated. Then, a mold having a protruding structure on the surface is heated to a temperature of Tm1 or more and Tg2 or more and pressed against the A layer side of the laminated structure, thereby forming a through hole in the A layer, and the B layer It is a manufacturing method of a thermoplastic film characterized by forming a crevice connected to a penetration hole.

Another manufacturing method according to the present invention is a laminated structure in which an A layer containing a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2 are laminated. On the other hand, a mold having a protruding structure on the surface is heated to a temperature of Tm1 or more and Tg2 or more and pressed against the A layer side of the laminated structure, thereby forming a through hole in the A layer, and the B layer Forming a recess communicating with the through hole, and then peeling off the A layer and the B layer to obtain a thermoplastic film having a through hole containing the A layer. Is the method.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 are flowcharts showing an example of an embodiment according to the method for producing a thermoplastic film having a through hole of the present invention. FIG. 3 is a perspective view showing an example of a mold applied to the manufacturing method of the present invention.

First, as shown in FIG. 1 (a), a laminated structure 10 in which an A layer 11 and a B layer 12 are laminated, and a mold 20 in which independent protrusion structures are arranged at predetermined positions on the surface are prepared. The A layer 11 includes a thermoplastic resin P1 having a melting point Tm1, and the B layer includes a thermoplastic resin P2 having a glass transition temperature Tg2.

Here, as a ratio of each thermoplastic resin included in each layer, it is preferable that 60% by mass or more of the thermoplastic resin is included when the entire layer is 100% by mass. Furthermore, it is more preferable to contain 80 mass% or more. In addition to the thermoplastic resin P1 or the thermoplastic resin P2, each layer may contain an additive or a coating component for imparting moldability and releasability. In addition, although an upper limit is not specifically limited, 100 mass% becomes a substantial upper limit.

In addition, it is preferable that the interface between the A layer and the B layer can be peeled off, and the interface between the A layer and the B layer is laminated by using the action of an adhesive formed by coating or the like. preferable. In addition, in this embodiment, a two-layer stacked configuration of the A layer and the B layer is described, but another layer may be provided on the side opposite to the A layer with the B layer interposed therebetween. It is preferable to apply a material having the same configuration as that of the A layer to the coating on the surface of the A layer because the flatness after the molding becomes high.

A laminated structure refers to a structure in which two or more layers containing different components are laminated. In addition, the continuous structure film conveyed by roll to roll may be sufficient as a laminated structure, and a single wafer sheet may be sufficient as it.

The glass transition temperature is a method according to the method described in JIS K 7244-4 (1999). The sample dynamic amplitude speed (driving frequency) is 1 Hz, the tensile mode, the distance between chucks is 5 mm, and the heating rate is 2 ° C. This is the temperature at which tan δ is maximized when measuring the temperature dependence (temperature dispersion) in / min.

The melting point here is a melting point Tm in a temperature rising process (temperature rising rate: 20 ° C./min) obtained by DSC (differential calorimetry), and based on JIS K 7121 (1999) as described above. Heat at a rate of temperature increase from 25 ° C. to 300 ° C. at a rate of 20 ° C./min (1stRUN), hold in that state for 5 minutes, then rapidly cool to below 25 ° C., and then increase again from room temperature to 20 ° C./min. The melting point of the resin is determined by the temperature at the peak top in the 2ndRun crystal melting peak obtained by raising the temperature to 300 ° C. at a temperature rate.

In the present invention, the mold 20 having the protruding structure 21 on the surface is heated. Heating is performed so that the mold has a temperature range of Tm1 or more and Tg2 or more. Heating may be performed in a state where the mold and the laminated structure are in contact with each other. By keeping the contact, the planarity of the laminated structure can be maintained in a good state.

Although the upper limit of the heating temperature of the mold is not limited, it is preferably below the thermal decomposition point of the thermoplastic resin P1 and below the thermal decomposition point of the thermoplastic resin P2.

Next, as shown in FIG. 1B, the mold 20 is pressed and pressed so that the protruding structure surface is in contact with the surface of the layer A 11 of the laminated structure 10 in a heated state. When the protrusion structure 21 has an appropriate height by being pressurized, the protrusion structure penetrates the A layer 11 and penetrates to the B layer 12. And as FIG.1 (c) shows, it will be in the state which the metal mold | die 20 and the laminated structure 10 contact | abutted without gap.

The required pressure and pressing time at this time depend on the material of the film, the transfer shape, particularly the aspect ratio of the unevenness, and the preferable range of the press pressure is generally 1 to 100 MPa, and the preferable range of the molding time is 0.01. ~ 60 seconds.

A more preferable range of the pressing pressure is 10 to 80 MPa, and a more preferable range is 30 to 60 MP. A more preferable range of the molding time is 1 to 50 seconds, and a more preferable range is 3 to 30 seconds.

Further, the mold 20 may be pressed against the laminated structure 10 by position control. That is, the mold 20 may be moved to a preset position and pressed against the laminated structure 10. The preset position is a position where the plane including the protrusion structure of the mold can be in contact with the surface of the A layer without any gap.

It should be noted that after the pressure is increased, the pressure may be removed while maintaining the position of the mold, and the contact state between the mold 20 and the laminated structure 10 may be maintained.

Next, as shown in FIG. 1 (c), the mold is cooled while maintaining the pressurized state or the contacted state. Cooling is preferably performed to a glass transition temperature Tg2 or lower of the thermoplastic resin P2 constituting the B layer. Cooling to Tg2 or less is preferable because the resin deformation after the mold 20 is peeled from the laminated structure 10 can be suppressed, and a through hole can be formed with high accuracy.

Next, as shown in FIG. 1 (d), the laminated structure 10 is peeled from the mold 20. In peeling, the mold and the laminated structure are moved away from each other in the direction perpendicular to the surface of the laminated structure. In the case where the laminated structure is a continuous film, it is preferable to continuously apply a tension in the direction perpendicular to the surface of the laminated structure so that the linear peeling position moves continuously. . You may hold | maintain in this state and may decide to peel B layer just before using the film which has a through-hole. The B layer has a role as a cover film, and if it is peeled off immediately before use, the surface is hardly damaged, and since it can be handled as a thick and highly rigid film until just before use, it is preferable because workability is good.

Moreover, FIG. 2 adds the peeling process mentioned above. 2 (a) to 2 (d) are the same as FIGS. 1 (a) to 1 (d), and a description thereof will be omitted. In FIG. 2 (e), the A layer 11 is peeled from the B layer 12. Peeling is suppressed by applying tension to the A layer or B layer in the direction perpendicular to the surface of the A layer or B layer, and peeling so that the linear peeling position moves continuously. From the viewpoint of

By carrying out the above-described steps described with reference to FIG. 1 or FIG. 2, the A layer 11 becomes a film having a through-hole whose shape is controlled with high accuracy. Due to the above manufacturing method, the A layer is in a molten state at the time of molding. Therefore, when the protruding structure is pressed, the A layer causes plastic deformation with a behavior close to that of a viscous material, and through holes with less burrs are formed at the end face of the opening. Is done. In addition, when the protrusion pattern (protrusion structure) is pushed in, the B layer causes viscoelastic deformation, and the protrusion structure can smoothly enter the inside of the B layer, so that there is no burrs at the interface between the A layer and the B layer. A few beautiful end faces can be formed.

In the present invention, Tm1−Tg2 which is the difference between the melting point Tm1 of the thermoplastic resin P1 contained in the A layer 11 and the glass transition temperature Tg2 of the thermoplastic resin P2 contained in the B layer is −30 to 60 ° C. Preferably there is. When the temperature is lower than −30 ° C., a large force is required for deformation of the B layer, and therefore, when the through hole is formed, the protrusion structure may be prevented from smoothly entering the B layer. When the temperature is higher than 60 ° C., the elasticity of the B layer may be lowered, and the planarity of the interface between the A layer and the B layer may be lowered.

In the present invention, it is also one of preferred embodiments that Tm1-Tg2 is 5 to 60 ° C. That is, the material of the thermoplastic resin P1 contained in the A layer 11 is preferably 5 to 60 ° C. higher than the glass transition temperature Tg2 of the thermoplastic resin P2 contained in the B layer. More preferably, it is 20 to 50 ° C., and further preferably 30 to 40 ° C. When the temperature is lower than 5 ° C., a large force is required for deformation of the B layer, and therefore, when the through hole is formed, the protrusion structure may be prevented from smoothly entering the B layer. If the temperature is higher than 60 ° C., the elasticity of the B layer may be reduced, and the planarity of the A layer and the B layer may be reduced.

Further, from the viewpoint of suppressing burrs to the limit at the opening portion of the A layer at the boundary surface between the A layer and the B layer and molding with high accuracy, the difference between the melting point Tm1 and the glass transition temperature Tg2 (Tm1−Tg2). ) Is preferably −10 to 0 ° C. If it is less than −10 ° C., the dimensional accuracy of the opening may deteriorate. When the temperature is higher than 0 ° C., burrs may occur at the end face.

In other words, the B layer has a certain range of hardness at the time of molding, achieving both good flatness at the interface between the A layer and the B layer and high-precision through-hole molding in which burr is suppressed at the opening. Preferred above. Further, the storage elastic modulus of the resin contained in the B layer at the temperature of the mold at the time of molding is 0.005 to 0.5 GPa, more preferably 0.01 to 0.1 GPa. The burr suppression can be further enhanced by the flatness of the interface of the B layer and the opening in the through hole molding. If it is less than 0.005 GPa, the planarity of the interface between the A layer and the B layer may be deteriorated, and a through hole may not be formed in the A layer, or a burr may be easily generated at the opening of the through hole. On the other hand, when it exceeds 0.5 GPa, it is difficult to deform in the B layer, the protrusion structure of the mold is not inserted to the back, and it may be difficult to form a through hole with a predetermined shape accuracy.

Specifically, the main component of the thermoplastic resin constituting the A layer 11 is preferably a polyolefin resin such as polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene, and polymethylpentene because mold releasability is good. Preferably used. In addition, a main component means the component which occupies 50 mass% or more when the whole resin which comprises A layer is 100 mass%. In addition, 50 mass% or more is preferable and, as for the main component, 80 mass% or more is more preferable. In addition, although an upper limit is not specifically limited, 100 mass% becomes a substantial upper limit.

In the present invention, it is preferable that the thermoplastic resin P1 is polyethylene or polypropylene. By using polyethylene or polypropylene, it is possible to mold the through-holes at a relatively low temperature, and thus it is easy to increase productivity.

Specifically, the main component of the thermoplastic resin constituting the B layer 12 is preferably a polyester resin such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene, polystyrene, polypropylene, poly Polyolefin resins such as isobutylene, polybutene, polymethylpentene, polyamide resins, polyimide resins, polyether resins, polyesteramide resins, polyetherester resins, acrylic resins, polyurethane resins, polycarbonate resins, or poly A vinyl chloride resin or the like is preferably used. Particularly preferred is polymethyl methacrylate. In addition, a main component means the component which occupies 50 mass% or more when the whole resin which comprises B layer is 100 mass%. In addition, 50 mass% or more is preferable and, as for the main component, 80 mass% or more is more preferable.

In the present invention, the thermoplastic resin P2 is preferably polymethyl methacrylate or polycarbonate. Particularly preferred is polymethyl methacrylate. By using polymethyl methacrylate or polycarbonate, it is possible to accurately form the concave portion communicating with the through hole.

The A layer and the B layer may be a layer made of the above-mentioned resin alone, or may be a laminated body made of a plurality of resin layers. In this case, surface characteristics such as releasability and friction resistance can be imparted as compared with a single layer. Thus, even when it is set as the laminated body which consists of a some resin layer, in each layer of A layer and B layer, the main thermoplastic resin component should just satisfy the above-mentioned requirements.

Further, as a method for producing the A layer and the B layer, it is preferable to form a thermoplastic resin film by melt extrusion. When a release layer, an adhesive layer, or the like is provided on the surface layer, a method of co-extrusion and processing into a film may be used, but it may be provided by coating after film formation. Moreover, you may use the method of carrying out extrusion lamination of the surface layer raw material to the film produced with the single film. As the lamination of the A layer and the B layer, a method of laminating by pressing with a roll and a method of heat laminating with a heated roll or the like can be applied.

Furthermore, various additives can be added to the film applied to the present invention at the time of polymerization or after polymerization. Examples of additives that can be added and blended include, for example, organic fine particles, inorganic fine particles, dispersants, dyes, fluorescent brighteners, antioxidants, weathering agents, antistatic agents, mold release agents, thickeners, Examples include plasticizers, pH adjusters, and salts. In particular, as a releasing agent, low surface tension carboxylic acids such as long chain carboxylic acids or long chain carboxylates and derivatives thereof, and low surface tension alcohols such as long chain alcohols and derivatives thereof, and modified silicone oils. It is preferable to add a small amount of a compound or the like during polymerization.

The preferred thickness (thickness, film thickness) of the A layer applied to the present invention is preferably in the range of 5 to 50 μm, more preferably 10 to 40 μm, and still more preferably 10 to 30 μm. If it is less than 5 μm, it may be difficult to handle. On the other hand, when the thickness is larger than 50 μm, the tip temperature of the mold is likely to change when the through hole is formed, and burrs may be easily generated on the end surface during penetration.

Further, the hole diameter of the through hole is preferably 1 to 100 μm. More preferably, it is 20 to 80 μm, and particularly preferably 30 to 50 μm. Here, the hole diameter is the hole diameter of the opening formed on the B layer side surface of the A layer. If it is a circle, it is the diameter, and if it is not a circle, it is the diameter when the opening is replaced with a circle of equal area. If the hole diameter is less than 1 μm, it may be difficult in terms of accuracy, and if it is larger than 100 μm, a large pressure may be required for forming the through-hole, and the apparatus may be enlarged. When the thickness is larger than 100 μm, mechanical processing such as punching is often suitable.

Next, the mold shape will be described with reference to FIGS. FIG. 3 is a perspective view showing an example of a mold applied to the present invention, and FIGS. 4A and 4B are cross-sectional views showing an example of a mold applied to the present invention.

A protrusion structure 21 is disposed at a predetermined position on the outer surface of the mold 20. The protruding structure refers to a convex structure provided on a mold, and the protruding structure may be provided with only the same shape on the mold, or may be provided with a plurality of different shapes.

The arrangement and density of the protrusion structure are preferably the same as the arrangement and density of the through holes required as product specifications. Generally, the pitch is 100 nm to 1 mm. Note that the pitch means a repetition interval of the protrusion structure.

The material of the mold is preferably a metal having high strength and thermal conductivity, such as nickel, steel, stainless steel, or copper. Moreover, you may use what gave the outer surface the plating in order to improve workability.

The height and cross-sectional shape of the protrusion structure are determined by the required shape of the through hole and the thickness of the film. The height of the protruding structure is preferably a length that penetrates the thickness of the A layer 11. That is, it is preferable to have a height that penetrates the A layer 11 when the mold 20 is in close contact with the laminated structure 10 during molding.

Examples of specific shapes will be described with reference to FIGS. The protrusion structure shown in FIG. 4A is a protrusion structure in which a cone and a cylinder are connected. The protrusion structure shown in FIG. 4B is a protrusion structure having only a cone. In any shape, the tip is preferably pointed rather than flat. In particular, a connection structure in which the protrusion structure has a weight shape and a cylindrical shape is preferable. This is because when the tip has a weight shape, the pressure applied to the laminated structure at the start of molding is increased to facilitate deformation. Further, by forming a cylindrical shape in the middle, a through hole having a high dimensional accuracy and a constant hole diameter can be formed. In addition, the structure etc. which combined the pyramid type | mold and the square pillar other than the shape quoted above may be sufficient.

Each mold with a protrusion structure on the surface is made by directly cutting, laser processing or electron beam processing on the metal surface, or by direct cutting, laser processing or electron beam processing on the plating film formed on the metal surface. And a method of electroforming these. Also, after applying the resist on the substrate, forming the resist with a predetermined patterning by photolithography technique, etching the substrate to form a recess, and removing the resist to obtain the inverted pattern by electroforming Etc. A cone-shaped pattern can be obtained by applying anisotropic etching. As the substrate, a silicon substrate or the like can be applied in addition to the metal plate.

A through-hole is a space that penetrates from one side of the layer to the other. Moreover, the recessed part connected to a through-hole means the recessed part of the B layer connected with the through-hole formed in the A layer by protrusion structure.

The film having a through hole of the present invention can be manufactured by a process through an apparatus as shown in FIGS. 5 and 6, for example. 5 and 6 show a through hole made of the A layer by forming a through hole in the A layer of the film-like laminated structure formed by laminating the A layer and the B layer, and further peeling the A layer and the B layer. The cross-sectional schematic of the manufacturing apparatus for manufacturing the film which has this is shown.

In the example shown in FIG. 5, an unwinding unit 52 for pulling out a laminated structure 50 in which a film made of an A layer and a film made of a B layer are laminated in advance from an unwinding roll 51, and heated gold having a protrusion structure formed on the surface. The mold 53 is pressed against the laminated structure 50 sent intermittently and pressurized, and then cooled while maintaining the contact state, thereby forming a predetermined through-hole in the A layer 50a of the laminated structure 50. . At the same time, a concave portion communicating with the through hole is formed in the B layer by the protruding structure.

From a press unit 54 for a pressure transfer process for forming a predetermined through hole, a peeling means 55 for peeling the laminated structure 50 attached to the mold 53 in the pressure transfer process from the mold 53, and the A layer 50a. Each film is wound around each of the winding rolls 57 and 58 through a film peeling device 56 for peeling the film formed and the film formed of the B layer 50b. The peeling means 55 consists of a pair of parallel arrangement rolls which hold | grip so that the laminated structure 50 may be held in S shape. One surface of the laminated structure 50 sent intermittently is thermoformed by the die 53 in the press unit 54, and after the thermoforming, the peeling means 55 is moved toward the upstream side, whereby the die 53 is moved. The laminated structure 50 that has been attached to is sequentially peeled off from the mold 53.

In FIG. 5, reference numeral 59 denotes a pressure plate, and 60 and 61 denote buffer means provided to smoothly perform intermittent conveyance in the mold 53 portion of the laminated structure 50. By such a process, it becomes possible to perform the formation of through holes in the A layer and the formation of recesses in the B layer (thermoforming) intermittently with high productivity.

In the example shown in FIG. 6, films constituting the A layer 71 and the B layer 72 are drawn from the unwinding rolls 73 and 74, and the laminated structure 70 is formed by the laminating device 75. Thereafter, the laminated structure 70 is supplied by a heating roll 76 onto an endless belt-shaped mold 77 having a protrusion structure formed on the heated surface.

A protrusion structure is formed on the outer surface of the mold 77 and is heated by the heating roll 76 immediately before coming into contact with the laminated structure 70. The laminated structure 70 that is continuously supplied is pressed against the surface on which the protruding structure of the mold 77 is processed by the nip roll 78, and a through hole is formed in the A layer 71 of the laminated structure. At the same time, a concave portion communicating with the through hole is formed in the B layer 72.

Thereafter, the laminated structure 70 is conveyed to the outer surface position of the cooling roll 79 in a state of being in close contact with the surface of the mold 77. The laminated structure 70 is cooled by heat conduction through a mold 77 by a cooling roll 79 and then peeled off from the mold 77 by a peeling roll 80 and peeled into a film composed of an A layer and a film composed of a B layer. Each film is taken up by take-up rolls 82 and 83 through a peeling device 81. By such a process, it becomes possible to thermoform a film composed of the A layer in which the through holes are formed continuously with high productivity.

[Application example]
In the method for producing a thermoplastic film described above, a shape having a fine pore size ranging from a micron size to a nano size can be freely designed, and a thermoplastic film can be produced inexpensively with high productivity. The thermoplastic film obtained by the production method of the present invention has micron-sized to nano-sized fine pore diameters uniformly formed. Therefore, filtration, cell culture, cell separation, gas permeation, moisture permeation that require through holes are required. Etc. are preferably used.

(Example 1)
(1) Laminated structure A film having a thickness of 30 μm containing a polymer mainly composed of polypropylene (melting point: 144 ° C.) in the A layer, and a polymer mainly composed of polymethyl methacrylate (PMMA) in the B layer (glass transition temperature of 105 A film having a thickness of 175 μm was used. One surface layer of the A layer has a 6 μm thick adhesive layer mainly composed of low density polyethylene. The adhesive layer of A layer was laminated so that it might adhere to the surface of B layer, and the laminated structure was comprised.

(2) Mold A mold having a triangular pyramid protrusion structure disposed on the entire surface was used. The triangular pyramid is a regular triangle whose bottom is 230 μm on a side, has a height of 70 μm, and is arranged on the entire surface without any gaps. The region where the protrusion structure is processed is a region of 200 mm (film width direction) × 400 mm (film transport direction). The material of the mold was a 20 mm thick copper base metal with a nickel plating film on the surface, and a triangular pyramid pattern was formed on the plating film by machining.

(3) Molding apparatus and conditions The apparatus as shown in FIG. 5 was applied. The press unit is a mechanism that is pressurized by a hydraulic pump. Two pressurizing plates are attached inside the press unit, and are connected to a heating device and a cooling device, respectively. The mold is placed on the upper surface of the lower pressure plate. A peeling means for peeling the film attached to the mold is installed in the press unit.

The mold temperature at the time of molding was 150 ° C., and the pressure was 5 MPa over the entire surface. The pressurization time was 30 seconds. The mold temperature at the time of peeling was 80 ° C. By peeling the film from the mold, a thermoplastic film having an A layer and a B layer, the A layer having a through hole, and the B layer having a recess communicating with the through hole is obtained. It was.

The thermoplastic film (film peeled from the mold) was continuously sent to the downstream side of the winding device, and the A layer and the B layer were peeled off and wound up. This obtained the thermoplastic film containing A layer which has a through-hole.

(4) Molding results Photographs taken with a scanning electron microscope (Keyence VE-7800, Inc.) of the molded film (A layer) are shown in FIGS. FIG. 7 is a photograph of the A layer as seen from the mold contact surface, and FIG. 8 is a photograph of the cross section of the A layer. Through holes having a triangular opening with a side of 45 μm were uniformly formed as designed. If the triangular shape of the opening is replaced with a circle of equal area, the hole diameter is equivalent to 33 μm. Further, the film composed of the B layer was uniformly formed with recesses communicating with the through holes corresponding to the triangular pyramid protrusion shape.

(Example 2)
(1) Laminated structure A film having a thickness of 30 μm containing a polymer (melting point: 144 ° C.) mainly composed of polypropylene in the A layer and a polymer (glass transition temperature: 146 ° C.) mainly composed of polycarbonate (PC) in the B layer. A film having a thickness of 180 μm was used. One surface layer of the A layer has a 6 μm thick adhesive layer mainly composed of low density polyethylene. The adhesive layer of A layer was laminated so that it might adhere to the surface of B layer, and the laminated structure was comprised.

The mold temperature at the time of molding was 160 ° C., and the pressure was 5 MPa over the entire surface. The pressurization time was 30 seconds. The mold temperature at the time of peeling was 80 ° C. By peeling the film from the mold, a thermoplastic film having an A layer and a B layer, the A layer having a through hole, and the B layer having a recess communicating with the through hole is obtained. It was.

The thermoplastic film (released from the mold) was continuously sent to the downstream side of the winding device, and the A layer and the B layer were peeled off and wound up. This obtained the thermoplastic film containing A layer which has a through-hole.

(4) Molding results Photographs taken with a scanning electron microscope (Keyence VE-7800, Inc.) of the molded film (A layer) are shown in FIGS. FIG. 9 is a photograph of the A layer viewed from the mold contact surface, and FIG. 10 is a photograph of a cross section of the A layer. Through holes having a triangular opening with a side of 45 μm were uniformly formed as designed. When the triangular shape of the opening is replaced with a circle of equal area, the hole diameter is equivalent to 33 μm. Further, as can be seen from FIG. 10, a through-hole film having a high flatness on the lower surface of the A layer in FIG. 10 (the surface in contact with the B layer before peeling) and few burrs was obtained.

Further, the film composed of the B layer was uniformly formed with recesses communicating with the through holes corresponding to the triangular pyramid protrusion shape.

(Comparative Example 1)
(1) Laminated structure A film having a thickness of 30 μm containing a polymer mainly composed of polypropylene (melting point: 144 ° C.) in the A layer, and a polymer mainly composed of polymethyl methacrylate (PMMA) in the B layer (glass transition temperature of 105 A film having a thickness of 175 μm was used. One surface layer of the A layer has a 6 μm thick adhesive layer mainly composed of low density polyethylene. The adhesive layer of A layer was laminated so that it might adhere to the surface of B layer, and the laminated structure was comprised.

The mold temperature during molding was 130 ° C., and the pressure was 5 MPa over the entire surface. The pressurization time was 30 seconds. The mold temperature at the time of peeling was 80 ° C. The peeled film was sent to the winding device side on the downstream side, the A layer and the B layer were peeled off, and each was wound up.

(4) Molding results Photographs taken with a scanning electron microscope (Keyence VE-7800, Inc.) of the molded film (A layer) are shown in FIGS. FIG. 11 is a photograph of the A layer viewed from the mold contact surface, and FIG. 12 is a photograph of the cross section of the A layer. No through hole was obtained in the A layer. Further, as can be seen from FIG. 12, the flatness of the lower surface of the A layer in FIG. 12 (the surface that was in contact with the B layer before peeling) was poor.

10: Laminated structure 11: A layer 12: B layer 20: Mold 21: Protrusion structure 50: Laminated structure 50a: A layer 50b: B layer 51: Unwinding roll 52: Unwinding unit 53: Mold 54: Press unit 55: peeling means 56: film peeling device 57, 58: take-up roll 59: pressure plate 60, 61: buffer means 62: take-up unit 70: laminated structure 71: A layer 72: B layers 73, 74 : Unwinding roll 75: Laminating apparatus 76: Heating roll 77: Die 78: Nip roll 79: Cooling roll 80: Peeling roll 81: Film peeling apparatus 82, 83: Winding roll

Claims

A mold having a protruding structure on the surface of a laminated structure in which an A layer containing a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2 are laminated. Heating to a temperature of Tm1 or higher and Tg2 or higher and pressing against the A layer side of the laminated structure, thereby forming a through hole in the A layer and forming a recess in the B layer communicating with the through hole. A method for producing a thermoplastic film.
A mold having a protruding structure on the surface of a laminated structure in which an A layer containing a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2 are laminated. Heating to a temperature of Tm1 or higher and Tg2 or higher, and pressing the laminated structure against the A layer side, thereby forming a through hole in the A layer, forming a recess in the B layer communicating with the through hole, and Then, the said A layer and the said B layer are peeled, The thermoplastic film which has a through-hole containing the said A layer is obtained, The manufacturing method of the thermoplastic film characterized by the above-mentioned.
3. The method for producing a thermoplastic film according to claim 1, wherein a difference (Tm1−Tg2) between the melting point Tm1 and the glass transition temperature Tg2 is −30 to 60 ° C.
The method for producing a thermoplastic film according to claim 3, wherein the difference (Tm1-Tg2) between the melting point Tm1 and the glass transition temperature Tg2 is -10 to 0 ° C.
The method for producing a thermoplastic film according to any one of claims 1 to 4, wherein the thermoplastic resin P1 is polyethylene or polypropylene.
The method for producing a thermoplastic film according to any one of claims 1 to 5, wherein the thermoplastic resin P2 is polymethyl methacrylate or polycarbonate.
The method for producing a thermoplastic film according to any one of claims 1 to 6, wherein the through-hole has a diameter of 1 to 100 µm.
The method for producing a thermoplastic film according to any one of claims 1 to 7, wherein the layer A has a thickness of 5 to 50 袖 m.
The method for producing a thermoplastic film according to any one of claims 1 to 8, wherein the protrusion structure is a structure in which a weight shape and a columnar shape are connected.