TWI624370B - Method for moving thermoplastic film - Google Patents

Abstract

The mold having the protrusion structure on the surface is heated to Tm1 by a laminated structure in which at least the layer A mainly composed of the thermoplastic resin P1 having the melting point Tm1 and the layer B having the thermoplastic resin P2 having the glass transition temperature Tg2 are formed. When the temperature is higher than Tg2 and is pressed against the layer A side of the laminated structure, the A layer can be placed at a desired position and density distribution to form a through hole having a desired shape.

Description

Method for producing thermoplastic film

This invention relates to a method of making a thermoplastic film having through-holes. The film having the through-hole obtained by the method can be used as a member having a fine through-hole of a micron size to a nanometer size which has functions of filtration, cell culture, cell separation, gas penetration, and moisture permeability. Moreover, in such an application, in order to achieve high performance, it is particularly suitable for use in a thermoplastic film having a hole shape or a through-hole controlled by high precision.

Examples of the method for producing a thermoplastic film having a hole shape or a through-hole controlled by high precision include injection molding, electron beam processing on a film, etching, hot stamping, and the like. Injection molding can be formed into a film having a through hole by filling a molten resin in a mold in which protrusions are formed. Further, electron beam processing can form a through hole by irradiating an electron beam onto the surface of the film to melt it from the surface to the inside. Further, etching can be performed by bringing an etching material made of a gas or a liquid into contact with an opening other than the region where the surface of the film is shielded, and gradually removing the resin by chemical or physical means to form a through hole.

Further, Patent Document 1 and Patent Document 2 disclose a hot stamping technique in which a thermoplastic film is pressed against a heated surface having a protruding structure to form a through hole in the film. Again, as In the method of improving the precision of the through-hole forming, Patent Document 3 discloses a method of applying a molten resin to a surface of a mold on which a protrusion is formed, and then pressurizing the mold while pressing the pressure plate. A film having a through hole is produced.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-154852

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2013-30605

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2011-230396

In the injection molding, it is difficult to reduce the thickness of the film or to make the through holes fine. Further, since it is necessary to have a step of filling and removing the resin into the mold, it is impossible to handle the film in a roll-to-roll state, and there is a problem that productivity is low. Further, in the electron beam processing, since it requires a large amount of processing time, there is a problem that productivity is low and it is difficult to apply it to mass production. Further, in the etching, there is a problem that it is difficult to form a uniform aperture in the depth direction. Further, in the imprint technique disclosed in Patent Document 1 or Patent Document 2, it is difficult to form a through hole having few burrs on the edge surface of the opening. The reason for this is that the deformation of the resin is governed by the viscoelastic properties and is not suitable for plastic deformation of the opening. In the manufacturing method by the melt transfer technique disclosed in Patent Document 3, since it is necessary to have a step of applying a resin to the mold, and heating and cooling the mold and taking out the product, it is impossible to handle the film in the roll-to-roll state. There is a problem of low productivity.

In order to solve the above problems, the present invention provides a method of producing a thermoplastic film.

(1) A method for producing a thermoplastic film characterized by comprising a laminated structure comprising at least 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 The mold having the protrusion structure on the surface is heated up to a temperature of Tm1 or more and Tg2 or more and pressed against the A layer side of the laminated structure, and a through hole is formed in the A layer, and a concave portion communicating with the through hole is formed in the B layer.

(2) A method for producing a thermoplastic film characterized by comprising a laminated structure comprising at least 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 The mold having the protrusion structure on the surface is heated up to a temperature of Tm1 or more and Tg2 or higher and pressed against the layer A side of the layered structure, and a through hole is formed in the layer A, and a concave portion communicating with the through hole is formed in the layer B, and further Thereafter, the layer A and the layer B were peeled off to obtain a thermoplastic film having a through hole including the layer A.

(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 according to any one of (1) to (4) wherein the thermoplastic resin P1 is polyethylene or polypropylene.

(6) The manufacturer of the thermoplastic film according to any one of (1) to (5) The method 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 through hole has a pore diameter of from 1 to 100 μm.

(8) The method for producing a thermoplastic film according to any one of (1) to (7) wherein the layer A has a thickness of 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 tapered shape and a columnar shape are connected.

According to the present invention, the mold having the protrusion structure on the surface is heated by the laminated structure of the layer A containing at least the thermoplastic resin P1 having the melting point Tm1 and the layer B containing the thermoplastic resin P2 having the glass transition temperature Tg2. The temperature of Tm1 or more and Tg2 or more is pressed against the layer A side of the laminated structure, and the A layer can be disposed at a desired position and density distribution to form a through hole having a desired shape.

10‧‧‧Laminated structure

11‧‧‧A floor

12‧‧‧B layer

20‧‧‧Mold

21‧‧‧Protruding structures

50‧‧‧Multilayer structure

50a‧‧‧A floor

50b‧‧‧B layer

51‧‧‧Rolling roll

52‧‧‧Withdraw unit

53‧‧‧Mold

54‧‧‧ Pressurizing unit

55‧‧‧Dissipation means

56‧‧‧film stripping device

57, 58‧‧‧Winding rolls

59‧‧‧ Pressurized plate

60, 61‧‧‧ buffer means

62‧‧‧Winding unit

70‧‧‧Laminated structure

71‧‧‧A floor

72‧‧‧B layer

73, 74‧‧‧ Roll out rolls

75‧‧‧Laminated device

76‧‧‧heating roller

77‧‧‧Mold

78‧‧‧Clamping roller

79‧‧‧Cooling roller

80‧‧‧ peeling roller

81‧‧‧film stripping device

82, 83‧‧‧Winding rolls

Fig. 1 (a) to (d) are flowcharts showing an example of an embodiment of a method for producing a thermoplastic film having a through hole according to the present invention.

Fig. 2 (a) to (e) are flowcharts showing an example of an embodiment of a method for producing a thermoplastic film having a through hole according to the present invention.

Fig. 3 is a perspective view showing an example of a mold suitable for the production method of the present invention.

Fig. 4 (a) and (b) are cross-sectional views showing an example of a mold which is applied to the present invention.

Fig. 5 is a cross-sectional conceptual view showing an example of an apparatus for realizing a method for producing a film having a through hole of the present invention.

Fig. 6 is a cross-sectional conceptual view showing an example of an apparatus for realizing a method for producing a film having a through hole of the present invention.

Fig. 7 is a surface photograph obtained by a scanning electron microscope of a film produced by the production method of the present invention described in Example 1.

Fig. 8 is a cross-sectional photograph obtained by a scanning electron microscope of a film produced by the production method of the present invention described in Example 1.

Fig. 9 is a surface photograph obtained by a scanning electron microscope of a film produced by the production method of the present invention described in Example 2.

Fig. 10 is a cross-sectional photograph obtained by a scanning electron microscope of a film produced by the production method of the present invention described in Example 2.

Fig. 11 is a surface photograph obtained by a scanning electron microscope of a film produced by the production method of the present invention described in Comparative Example 1.

Fig. 12 is a cross-sectional photograph obtained by a scanning electron microscope of a film produced by the production method of the present invention described in Comparative Example 1.

[Formation of the Invention]

The present invention relates to a method of making a thermoplastic film having a through-hole.

One of the production methods of the present invention is a method for producing a thermoplastic film characterized by comprising an A layer containing at least a thermoplastic resin P1 having a melting point Tm1 and a B layer containing a thermoplastic resin P2 having a glass transition temperature Tg2. a laminated structure, which heats a mold having a protruding structure on the surface until a temperature of Tm1 or more and Tg2 or more and presses The layer is formed on the side of the layer A of the laminated structure, and a through hole is formed in the layer A, and a recess that communicates with the through hole is formed in the layer B.

Further, another manufacturing method of the present invention is a method for producing a thermoplastic film characterized by comprising an A layer containing at least a thermoplastic resin P1 having a melting point Tm1 and a B containing a thermoplastic resin P2 having a glass transition temperature Tg2. The laminated structure of the layer is heated to a temperature of Tm1 or more and a temperature of Tg2 or more and pressed against the layer A side of the laminated structure, and a through hole is formed in the layer A and is connected to the through layer in the layer B. Further, the concave portion of the hole is further peeled off from the layer A and the layer B, and a thermoplastic film having a through hole having the layer A is obtained.

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

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

First, as shown in Fig. 1(a), the laminated structure 10 in which the A layer 11 and the B layer 12 have been laminated is prepared, and the mold 20 in which the projections are provided at the predetermined positions on the surface is prepared. The A layer 11 is a thermoplastic resin P1 having a melting point Tm1, and the B layer is a thermoplastic resin P2 containing a glass transition temperature Tg2.

Here, the ratio of each of the thermoplastic resins contained in each layer is preferably 60% by mass or more of the thermoplastic resin when the entire layer is 100% by mass. Further, it is preferably contained in an amount of 80% by mass or more. Also, in each layer, except for the thermoplastic resin P1 or thermoplastic resin In addition to P2, an additive or a coating component for imparting formability or mold release property may be contained. Further, although the upper limit is not particularly limited, 100% by mass is a substantial upper limit.

Further, the interface between the layer A and the layer B is preferably peelable, and the interface between the layer A and the layer B is preferably laminated by the action of an adhesive formed by coating or the like. Further, in the present embodiment, a two-layer laminated structure of the A layer and the B layer is described. However, another layer may be provided on the side opposite to the A layer in the B layer. When the surface of the layer A is coated with the same material as the layer A, it is preferable because the planarity after molding becomes high.

The laminated structure system refers to a structure in which two or more layers containing different compositions are laminated. Further, the laminated structure may be a continuous film which is conveyed by a roll to a roll, or may be a single piece.

The glass transition temperature means that the sample has a dynamic amplitude velocity (driving frequency) of 1 Hz, a tensile mode, a cross-clamp distance of 5 mm, and a temperature increase rate of 2 ° C/min according to the method described in JIS K 7244-4 (1999). In the case of temperature dependence (temperature dispersion), tan δ is the temperature at which the temperature is extremely large.

In addition, the melting point is a melting point Tm in a temperature rising process (temperature rising rate: 20 ° C /min) obtained by DSC (fine scanning calorimetry), and is used in the same manner as described above in accordance with JIS K 7121 (1999). The method is heated from 25 ° C to 300 ° C (1 s RUN) at a temperature increase rate of 20 ° C / min, kept in this state for 5 minutes, and then quenched so as to be 25 ° C or less, and then at 20 ° C / min. The temperature increase rate was raised from room temperature to 300 ° C, and the peak temperature of the peak of the crystal dissolution peak of the obtained 2nd RUN was set as the melting point of the resin.

The present invention preliminarily heats the mold 20 having the protrusion structure 21 on its surface. The heating is performed such that the mold has a temperature range of Tm1 or more and Tg2 or more. It is also possible to heat the mold in contact with the laminated structure. By the prior contact, the planarity of the laminated structure can be maintained in a good state in advance.

Further, although the upper limit of the mold heating temperature is not limited, it is preferably not more than the thermal decomposition temperature of the thermoplastic resin P1 and not more than the thermal decomposition temperature of the thermoplastic resin P2.

Next, as shown in FIG. 1(b), the mold 20 is pressed and pressed so that the projection structure surface comes into contact with the surface of the A layer 11 of the laminated structure 10 in a heated state. If the protrusion structure 21 has an appropriate height, the protrusion structure 21 will penetrate the A layer 11 and penetrate into the B layer 12 by pressurization. Then, as shown in FIG. 1(c), the mold 20 and the laminated structure 10 are connected to each other without a gap.

The necessary pressure and pressurization time at this time depends on the material of the film, the transfer shape, and particularly the aspect ratio of the unevenness, and the preferred range of the pressurization pressure is preferably from 1 to 100 MPa, and the molding time is preferred. The range is from 0.01 to 60 seconds.

A more preferable range of the pressurizing pressure is 10 to 80 MPa, and a still more preferable range is 30 to 60 MPa. Further, the forming time is more preferably in the range of 1 to 50 seconds, and still more preferably in the range of 3 to 30 seconds.

Further, the mold 20 can be pressed against the laminated structure 10 by position control. In other words, the mold 20 can be moved to the position set in advance and pressed against the laminated structure 10. The position set in advance means that the plane containing the protrusion structure of the mold can be joined to the A layer without any gap. The position of the surface.

Further, after the pressure is raised, the pressure is removed as it is while maintaining the position of the mold, and the contact state between the mold 20 and the laminated structure 10 is maintained.

Next, as shown in Fig. 1(c), the mold is cooled as it is in a state of being pressurized or in contact with it. The cooling is preferably carried out up to the glass transition temperature Tg2 of the thermoplastic resin P2 constituting the layer B. By cooling until Tg2 or less, it is possible to suppress deformation of the resin after the mold 20 is peeled off from the laminated structure 10, and it is possible to form a through hole having high precision.

Next, as shown in FIG. 1(d), the laminated structure 10 is peeled off from the mold 20. The peeling is moved in a direction perpendicular to the surface of the laminated structure so that the mold or the laminated structure is separated. In the case where the laminated structure is a continuous film, it is preferable to continuously apply tension to the vertical direction of the surface of the laminated structure, and to peel off the linear peeling position. It may also be set such that it remains in this state, and the B layer is peeled off immediately before the film having the through holes is used. The B layer has a function as a film, and if it is peeled off immediately before use, the surface is less likely to be scratched, and since it can be handled as a film having a high thickness and rigidity until it is used immediately, workability is good, which is preferable.

Moreover, the figure 2 adds the said peeling process. Since FIGS. 2(a) to (d) are the same as FIGS. 1(a) to (d), description thereof will be omitted. In Fig. 2(e), the A layer 11 is peeled off from the B layer 12. From the viewpoint of suppressing the peeling marks, it is preferable to set the peeling to the A layer or the B layer in the vertical direction with respect to the surface of the A layer or the B layer, and to continuously move the linear peeling position. Stripped.

By performing the above-described steps described in FIG. 1 or FIG. 2, the A layer 11 is formed into a film having a through hole having a high-precision controlled shape. According to the manufacturing method described above, the layer A is in a molten state at the time of molding, so that the layer A in the structure of the pressed protrusion is plastically deformed in a manner close to the path of the viscous material, and a through hole having few burrs is formed on the edge surface of the opening. Further, when the projection pattern (protrusion structure) is further pressed, since the B layer causes viscoelastic deformation, the projection structure can smoothly enter the inside of the B layer, so that even at the interface between the A layer and the B layer, a small amount of clean edges can be formed. Edge face.

Further, in the present invention, the difference Tm1 - Tg2 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 layer B is preferably -30 to 60 °C. When the temperature is lower than -30 ° C, since the deformation of the layer B requires a large force, when the through hole is formed, there is a case where the protrusion structure is prevented from smoothly entering the layer B. If it is higher than 60 ° C, the elasticity of the B layer is lowered, and the flatness of the interface between the A layer and the B layer is lowered.

In the present invention, Tm1-Tg2 of 5 to 60 ° C is also one of preferable forms. In other words, as the material of the thermoplastic resin P1 contained in the A layer 11, the melting point Tm is preferably 5 to 60 ° C higher than the glass transition temperature Tg2 of the thermoplastic resin P2 contained in the layer B. More preferably, it is 20 to 50 ° C, and still more preferably 30 to 40 ° C. When the thickness is lower than 5 ° C, since the deformation of the layer B requires a large force, when the through hole is formed, there is a case where the protrusion structure is prevented from smoothly entering the layer B. If it is higher than 60 ° C, the elasticity of the B layer is lowered, and the planarity of the A layer and the B layer is lowered.

Moreover, the opening of the A layer from the boundary surface between the A layer and the B layer is the most From the viewpoint of suppressing burrs to a large extent and forming with high precision, the difference (Tm1 - Tg2) between the melting point Tm1 and the glass transition temperature Tg2 is preferably -10 to 0 °C. Below -10 ° C, there is a case where the dimensional accuracy of the opening is lowered. If it becomes higher than 0 ° C, there is a case where the burrs on the edge faces are generated.

In other words, in the high-precision through-hole forming in which the interface between the A layer and the B layer is good, and the high-precision through-hole forming in which the burrs of the opening are suppressed, the hardness of the B layer in a certain range is preferable at the time of molding. Further, the storage elastic modulus of the resin contained in the layer B by the mold temperature at the time of molding is 0.005 to 0.5 GPa, and more preferably in the range of 0.01 to 0.1 GPa, and the plane of the interface between the layer A and the layer B can be further improved. Sexuality and suppression of the burrs of the openings at the time of forming the through holes. When the thickness is less than 0.005 GPa, the planarity of the interface between the layer A and the layer B is lowered, and the through hole is not formed in the layer A, or the burr is likely to occur in the opening of the through hole. On the other hand, when it exceeds 0.5 GPa, the B layer becomes difficult to be deformed, and the protruding structure of the mold cannot be inserted into the deep portion, and the formation of the through hole having a predetermined shape accuracy becomes difficult.

The main component of the thermoplastic resin constituting the A layer 11 is specifically a polyolefin resin such as polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene or polymethylpentene because it is a mold. It has a good mold release property and is preferably used. In addition, the main component is a component which occupies 50% by mass or more when the entire resin constituting the layer A is 100% by mass. Further, the main component is preferably 50% by mass or more, and more preferably 80% by mass or more. Further, although the upper limit is not particularly limited, 100% by mass is a substantial upper limit.

In the present invention, the thermoplastic resin P1 is preferably polyethylene or polypropylene. Because it can be in the lower phase by using polyethylene or polypropylene The through hole is formed at a temperature, so that productivity is easily improved.

As a main component of the thermoplastic resin constituting the B layer 12, specifically, polyethylene terephthalate, polyethylene-2,6-naphthalate, polytrimethylene terephthalate, a polyester resin such as polybutylene terephthalate; a polyolefin resin such as polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene or polymethylpentene; a polyamide resin; Polyimide resin, polyether resin, polyester amide resin, polyether ester resin, acrylic resin, polyurethane resin, polycarbonate resin, or polyvinyl chloride resin It is preferably used. Particularly preferred is polymethyl methacrylate. In addition, the main component is a component which occupies 50% by mass or more when the entire resin constituting the B layer is 100% by mass. Further, the main component is preferably 50% by mass or more, and more preferably 80% by mass or more.

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, the concave portion communicating with the through hole can be formed accurately.

The layer A or the layer B may be a layer composed of the above-mentioned resin simple substance, or may be a laminate body composed of a plurality of resin layers. In this case, it is possible to impart surface properties such as mold release property and abrasion resistance, etc., in comparison with the elemental layer. In this case, even in the case of forming a laminated body composed of a plurality of resin layers, the main thermoplastic resin components in the respective layers of the A layer and the B layer may satisfy the above requirements.

Moreover, as a manufacturing method of the A layer and the B layer, it is suitable to form a film by melt-extruding a thermoplastic resin. Set the release layer or adhesive layer In the case of the surface layer, it may be a method of processing into a film shape by co-extrusion, but it may be provided by coating after film formation. Further, a method of extruding a surface layer raw material and laminating a film formed into a single film may also be employed. Further, the laminate of the A layer and the B layer may be a method of laminating by a roll or the like, or a method of thermally laminating by a heated roller or the like.

Further, among the films which are suitable for use in the present invention, various additives can be added during or after the polymerization. Examples of the additive to which the blending can be added include, for example, organic fine particles, inorganic fine particles, a dispersing agent, a dye, a fluorescent whitening agent, an antioxidant, a weathering agent, an antistatic agent, a release agent, a tackifier, Plasticizers, pH adjusters and salts. In particular, it is preferred to carry out a low surface tension of a carboxylic acid or a derivative thereof having a low surface tension such as a long-chain carboxylic acid or a long-chain carboxylate, a long-chain alcohol or a derivative thereof, and a modified eucalyptus oil in a small amount during polymerization. An alcohol compound or the like is used as a release agent.

Further, a preferred thickness (film thickness) of the layer A to which the present invention is applied is preferably in the range of 5 to 50 μm, more preferably 10 to 40 μm, still more preferably 10 to 30 μm. When it is less than 5 μm, there is a case where it is difficult to operate. Moreover, in the case where it is larger than 50 μm, the tip temperature of the mold is easily changed when the through hole is formed, and the burr is likely to be generated on the edge surface at the time of penetration.

Further, the diameter of the through hole is preferably from 1 to 100 μm. More preferably, it is 20 to 80 μm, and particularly preferably 30 to 50 μm. Here, the aperture is a hole diameter of an opening formed on the side surface of the layer B of the layer A. If it is a circle, it is a diameter, and if it is a circle, it is a diameter when the opening is replaced with a circle of an equal area. When the pore diameter is less than 1 μm, there is a case where the precision is difficult; and in the case of being larger than 100 μm, a large pressing force is required to form the through hole. There is a situation in which the device is enlarged. Further, in the case of being larger than 100 μm, mechanical processing such as punching is often applied.

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

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

The arrangement or density of the projection structures is preferably set to be the same as the arrangement or density of the through holes required to make the article specifications. In general, it is between 100 nm and 1 mm. Also, the term "pitch" refers to the repeating interval of the protrusion structure.

The material of the mold is preferably a metal having a high strength and thermal conductivity. For example, nickel or steel, stainless steel, copper or the like is preferable. Further, in order to improve the workability of the outer surface, it is also possible to use a plated person.

The height or profile of the raised structure is determined by the shape of the desired through hole or the thickness of the film. The height of the projection structure is preferably a length that can penetrate the thickness of the A layer 11. That is, at the time of molding, when the mold 20 is in close contact with the laminated structure 10, the height of the A layer 11 can be penetrated.

A specific shape example will be described using Figs. 4(a) and 4(b). The protruding structure shown in Fig. 4(a) is a protruding structure in which a cone and a cylinder are joined together. The projection structure shown in Fig. 4(b) is only a conical projection structure. Regardless of any of the shapes, it is preferred that the tip end be flatter and sharper. The protruding structure is particularly preferably a tapered and cylindrical connecting structure. The reason is By the taper shape of the tip, the pressure applied to the laminated structure can be increased at the start of forming to make it easy to deform. Further, by forming a column shape from the middle, it is possible to form a through hole having a high dimensional precision and a constant hole diameter. Further, in addition to the above-described shapes, a configuration in which a pyramid shape and a quadrangular prism are combined may be employed.

A method for forming each mold having a protruding structure on the surface may be a method of performing direct cutting or laser processing or electron beam processing on a metal surface, or performing direct cutting or laser processing or electron beam on a plating film formed on a metal surface. A method of processing, a method of performing electroforming, and the like. Further, after applying a resistor to a substrate, a photoresist is formed in a predetermined pattern by a photolithography method, and then the substrate is etched to form a concave portion, and after the photoresist is removed, the reverse is obtained by electroforming. The method of the pattern, etc. By using anisotropic etching, a tapered pattern can be obtained. In addition to the metal plate, a tantalum substrate or the like can be used as the substrate.

The through hole refers to a space that passes from one side of the layer to the other side. Further, the recessed portion that communicates with the through hole refers to a recessed portion that is connected to the B layer of the through hole formed in the A layer by the protruding structure.

The film having the through holes of the present invention can be produced by the process of passing through the apparatus shown in Figs. 5 and 6. Fig. 5 and Fig. 6 are schematic cross-sectional views showing a manufacturing apparatus for forming a through hole by a layer A of a film-like laminated structure composed of a laminate of an A layer and a B layer, and further a layer A. A film having a through hole formed of the layer A was produced by peeling off from the layer B.

In the example shown in Fig. 5, a laminate of a film composed of a layer A and a film formed of a layer B is taken out from the take-up roll 51. The unwinding unit 52 of the structure 50 and the mold 53 having a projection structure and having a surface formed thereon are pressed by the intermittently transported laminated structure 50, and then cooled by being held in contact with each other. On the other hand, the A layer 50a of the laminated structure 50 forms a predetermined through hole. At the same time, a recess that communicates to the through hole by the protrusion structure is also formed in the B layer.

The peeling means 55 for the pressure transfer step for forming a predetermined through hole, the peeling means 55 for peeling the laminated structure 50 attached to the mold 53 in the press transfer step from the mold 53, and the A layer 50a The film and the film peeling device 56 which are formed by the film of the B layer 50b are formed, and the respective films are taken up to the respective take-up rolls 57 and 58. The peeling means 55 is constituted by a pair of parallel arrangement rolls that are sandwiched by the laminated structure 50 in an S-shape. In the pressurizing unit 54, one surface of the laminated structure 50 conveyed intermittently by the mold 53 is thermoformed, and after the hot forming, the peeling means 55 is moved to the upstream side to be attached to the mold 53. The laminated structure 50 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 for smoothly conveying the mold 53 portion of the laminated structure 50. Through such a procedure, the formation of the through hole of the A layer and the formation of the concave portion of the B layer (thermoforming) can be performed intermittently with high productivity.

In the example shown in Fig. 6, the film constituting the A layer 71 and the B layer 72 is taken out from the respective take-up rolls 73 and 74, and the laminated structure 70 is formed by the layering device 75. Thereafter, the laminated structure 70 is supplied to the mold 77 of the endless belt in which the heated surface is formed by the heating roller 76.

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

After that, the laminated structure 70 is conveyed to the outer surface position of the cooling roll 79 in a state in which it is in close contact with the surface of the mold 77. The laminated structure 70 is cooled by heat conduction through the mold 77 by the cooling roll 79, and then peeled off from the mold 77 by the peeling roller 80, and is formed into a film composed of a film of the A layer and a film of the B layer. The film peeling device 81 winds each film by the take-up rolls 82 and 83. Through such a procedure, the film formed of the A layer having the through holes can be continuously thermoformed with high productivity.

[Example of use]

In the above method for producing a thermoplastic resin film, a micron-sized to nano-sized pore diameter can be freely designed, and a thermoplastic resin film can be produced at a low cost and with good productivity. Since the thermoplastic resin film obtained by the production method of the present invention uniformly forms micropores having a micron size to a nanometer size, it is suitable for filtration, cell culture, cell separation, gas permeability, moisture permeability, and the like which require through holes.

[Examples] (Example 1)

(1) Laminated structure

Use a layer A containing a polymer based on polypropylene (melting point is A film having a thickness of 30 μm at 144 ° C) and a film having a thickness of 175 μm containing a polymer of polymethyl methacrylate (PMMA) as a main component (glass transition temperature: 105 ° C) were contained in the layer B. Further, the side surface layer of one of the A layers has an adhesive layer having a thickness of 6 μm mainly composed of low-density polyethylene. The laminated structure is formed by laminating the adhesive layer of the A layer so as to adhere to the surface of the B layer.

(2) mold

A mold having a triangular pyramidal projection configuration on the entire surface is used. One side of the bottom surface of the triangular pyramid system was an equilateral triangle of 230 μm, and the height was 70 μm, and the entire surface was arranged without a gap. The area processed by the protrusion structure is a region of 200 mm (film width direction) × 400 mm (film conveyance direction). The material of the mold is a method in which a nickel-plated film is formed on the surface of copper having a thickness of 20 mm as a base material, and a triangular pyramid pattern is formed on the plating film by mechanical processing.

(3) Forming equipment and conditions

The apparatus is a device as shown in Fig. 5. The pressurizing unit is provided with a pressurizing plate that is pressurized by a hydraulic pump, and is internally provided with two upper and lower pressure plates, and is connected to a heating device and a cooling device, respectively. The mold is placed on the upper surface of the lower pressure plate. Further, a peeling means for peeling off the film attached to the mold is provided in the pressurizing unit.

The mold temperature at the time of molding was 150 ° C, and the pressure was applied so as to apply a pressure of 5 MPa over the entire surface. The pressurization time is 30 seconds. Further, the mold temperature at the time of peeling was 80 °C. By peeling the film from the mold, a thermoplastic film having a layer A and a layer B having a through-hole and a thermoplastic film having a concave portion communicating with the through-hole in the layer B is obtained.

The thermoplastic film (the film peeled from the mold) is continuously fed to the side of the winding device on the downstream side, and the layer A and the layer B are peeled off. And each is taken. Thereby, a thermoplastic film containing the A layer having the through holes was obtained.

(4) Forming results

A photograph of the formed film (layer A) taken by a scanning electron microscope (Keyence VE-7800) is shown in Figs. 7 and 8. Fig. 7 is a photograph of the A layer viewed from the contact surface of the mold, and Fig. 8 is a photograph of the cross section of the A layer. According to the design, a through hole having a triangular opening portion having a side of 45 μm was uniformly formed. When the triangular shape of the opening is replaced by a circle of equal area, the aperture corresponds to formation of 33 μm. Further, the film formed in the B layer is uniformly formed with a concave portion that communicates with a through hole corresponding to the shape of the triangular pyramid protrusion.

(Example 2)

(1) Laminated structure

A film having a thickness of 30 μm containing a polymer mainly composed of polypropylene (melting point: 144 ° C) in the layer A, and a polymer having a polycarbonate (PC) as a main component (glass transition temperature: 146 ° C) was used in the layer B. A film having a thickness of 180 μm. Further, the side surface layer of one of the A layers has an adhesive layer having a thickness of 6 μm mainly composed of low-density polyethylene. The laminated structure is formed by laminating the adhesive layer of the A layer so as to adhere to the surface of the B layer.

(2) mold

A mold having a triangular pyramidal projection configuration on the entire surface is used. One side of the bottom surface of the triangular pyramid system was an equilateral triangle of 230 μm, and the height was 70 μm, and the entire surface was arranged without a gap. The area processed by the protrusion structure is a region of 200 mm (film width direction) × 400 mm (film conveyance direction). The material of the mold is a nickel-plated film on the surface of copper having a thickness of 20 mm as a base material. A triangular pyramid pattern is formed on the plated film by mechanical processing.

(3) Forming equipment and conditions

The apparatus is a device as shown in Fig. 5. The pressurizing unit is provided with a pressurizing plate that is pressurized by a hydraulic pump, and is internally provided with two upper and lower pressure plates, and is connected to a heating device and a cooling device, respectively. The mold is placed on the upper surface of the lower pressure plate. Further, a peeling means for peeling off the film attached to the mold is provided in the pressurizing unit.

The mold temperature at the time of molding was set to 160 ° C, and the pressure was applied so as to apply a pressure of 5 MPa over the entire surface. The pressurization time is 30 seconds. Further, the mold temperature at the time of peeling was 80 °C. By peeling the film from the mold, a thermoplastic film having a layer A and a layer B having a through-hole and a thermoplastic film having a concave portion communicating with the through-hole in the layer B is obtained.

The thermoplastic film (film peeled off from the mold) was continuously fed to the side of the winding device on the downstream side, and the layers A and B were peeled off and wound up. Thereby, a thermoplastic film containing the A layer having the through holes was obtained.

(4) Forming results

A photograph of the formed film (layer A) taken by a scanning electron microscope (Keyence VE-7800) is shown in Fig. 9 and Fig. 10. Fig. 9 is a photograph of the A layer viewed from the contact surface of the mold, and Fig. 10 is a photograph of the cross section of the A layer. According to the design, a through hole having a triangular opening portion having a side of 45 μm was uniformly formed. When the triangular shape of the opening is replaced by a circle of equal area, the aperture corresponds to formation of 33 μm. Further, as can be seen from Fig. 10, the lower surface of the layer A of Fig. 10 (the surface in contact with the layer B before peeling) has high planarity, and a through-hole film having few burrs can be obtained.

Further, the film formed in the B layer is uniformly formed with a concave portion that communicates with a through hole corresponding to the shape of the triangular pyramid protrusion.

(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 layer A, and a polymer having a polymethyl methacrylate (PMMA) as a main component in the layer B (glass transition temperature of 105) was used. °C) film having a thickness of 175 μm. Further, the side surface layer of one of the A layers has an adhesive layer having a thickness of 6 μm mainly composed of low-density polyethylene. The laminated structure is formed by laminating the adhesive layer of the A layer so as to adhere to the surface of the B layer.

(2) mold

A mold having a triangular pyramidal projection configuration on the entire surface is used. One side of the bottom surface of the triangular pyramid system was an equilateral triangle of 230 μm, and the height was 70 μm, and the entire surface was arranged without a gap. The area processed by the protrusion structure is a region of 200 mm (film width direction) × 400 mm (film conveyance direction). The material of the mold is a method in which a nickel-plated film is formed on the surface of copper having a thickness of 20 mm as a base material, and a triangular pyramid pattern is formed on the plating film by mechanical processing.

(3) Forming equipment and conditions

The apparatus is a device as shown in Fig. 5. The pressurizing unit is provided with a pressurizing plate that is pressurized by a hydraulic pump, and is internally provided with two upper and lower pressure plates, and is connected to a heating device and a cooling device, respectively. The mold is placed on the upper surface of the lower pressure plate. Further, a peeling means for peeling off the film attached to the mold is provided in the pressurizing unit.

The mold temperature at the time of molding was set to 130 ° C, and the pressure was applied so as to apply a pressure of 5 MPa over the entire surface. Pressurization time is 30 seconds . Further, the mold temperature at the time of peeling was 80 °C. The peeled film was sent out to the winding device side on the downstream side, and the A layer and the B layer were peeled off and each was taken up.

(4) Forming results

A photograph taken of a formed film (layer A) by a scanning electron microscope (Keyence VE-7800) is shown in Figs. 11 and 12 . Fig. 11 is a photograph of the A layer viewed from the mold contact surface, and Fig. 12 is a photograph of the A layer cross section. No through holes were obtained in the A layer. Further, as can be seen from Fig. 12, the lower surface of the layer A of Fig. 12 (the surface in contact with the layer B before peeling) has poor planarity.

Claims (9)

A method for producing a thermoplastic film characterized by having a laminate having a layer of at least a layer A containing a thermoplastic resin P1 having a melting point Tm1 and a layer B containing a thermoplastic resin P2 having a glass transition temperature Tg2 The mold of the structure is heated up to a temperature of Tm1 or more and Tg2 or more and pressed against the layer A side of the laminated structure, and a through hole is formed in the layer A, and a concave portion communicating with the through hole is formed in the layer B. A method for producing a thermoplastic film characterized by having a laminate having a layer of at least a layer A containing a thermoplastic resin P1 having a melting point Tm1 and a layer B containing a thermoplastic resin P2 having a glass transition temperature Tg2 The mold of the structure is heated up to a temperature of Tm1 or more and Tg2 or more and pressed against the layer A side of the laminated structure, and a through hole is formed in the layer A, and a concave portion communicating with the through hole is formed in the layer B, and further thereafter, The layer A was peeled off from the layer B to obtain a thermoplastic film having a through hole containing the layer A. The method for producing a thermoplastic film according to claim 1 or 2, 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 a difference (Tm1 - Tg2) between the melting point Tm1 and the glass transition temperature Tg2 is -10 to 0 °C. A method of producing a thermoplastic film according to claim 1 or 2, wherein the thermoplastic resin P1 is polyethylene or polypropylene. A method of producing a thermoplastic film according to claim 1 or 2, wherein the thermoplastic resin P2 is polymethyl methacrylate or polycarbonate. A method of producing a thermoplastic film according to claim 1 or 2, wherein the through hole has a pore diameter of from 1 to 100 μm. A method of producing a thermoplastic film according to claim 1 or 2, wherein the layer A has a thickness of 5 to 50 μm. The method for producing a thermoplastic film according to claim 1 or 2, wherein the protrusion structure is a structure in which a tapered shape and a cylindrical shape are joined.