JP2015071249A - Manufacturing method of water-repellent film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a water-repellent film capable of manufacturing a water-repellent film having sufficient water repellency.SOLUTION: A manufacturing method of water-repellent film has: a process of heating a material film (step S1); a process of heating a surface of an embossing roll (step S2); a process of conveying the material film at predetermined speed and conveying the film between the embossing roll and a pressure roll (step S3); a process of embossing a surface of the heated material film by the embossing roll and the pressure roll at predetermined pressure (step S4); a process of stopping conveyance of the material film (step S5); a process of cooling the surface of the embossing roll (step S6); and a process of restarting conveyance of the embossed material film and peeling off the embossed material film from the embossing roll (step S7).

Description

  The present invention relates to a method for producing a water-repellent film having high water repellency.

  The water repellency resulting from the surface microstructure is known as the Lotus effect. In order to realize such water repellency, various techniques have been developed. In general, in order to develop water repellency on the product surface, a chemical method of applying a fluororesin or the like is mainly used (see Patent Documents 1 and 2).

  In addition, as a chemical method, a technology that is applied to a non-adsorbing container for containing food, medical products, etc. has been developed by forming water-repellent silica fine particles on the product surface to form a fine uneven structure. (See Patent Document 3).

  On the other hand, there is also a technology for preventing liquid splashing by a water repellent effect by forming a fine uneven structure on a container lid by a physical method (see Patent Document 4). In addition, in order to physically impart water repellency to a film, a technique for creating a plastic molded body by injection molding using a mold having a fine periodic structure has been developed (see Patent Document 5).

Japanese Utility Model Publication No. 5-35659 Japanese Patent No. 3623540 JP 2010-254377 A JP 2009-107695 A JP 2012-66417 A

  However, when using a chemical method like the techniques described in Patent Documents 1 to 3, there is a problem that the influence on the human body and the environment must be considered. Further, the techniques described in Patent Documents 4 and 5 do not provide a film having sufficient water repellency.

  Then, this invention makes it a subject to provide the manufacturing method of the water repellent film which can manufacture the water repellent film which has sufficient water repellency.

  The method for producing a water-repellent film according to the present invention includes a step of heating a material film, a step of heating the surface of an embossing roll, and conveying the material film between an embossing roll and a pressure roll at a predetermined speed. A step of embossing the surface of the heated material film with a predetermined pressure by an embossing roll and a pressure roll, and a step of peeling the material film subjected to the embossing from the embossing roll. It is characterized by having.

  According to the method for producing a water-repellent film of the present invention, the surfaces of the material film and the embossing roll are heated, the material film is conveyed at a predetermined speed, and conveyed between the embossing roll and the pressure roll, and heated. The embossing roll and pressure roll are embossed on the surface of the material film at a predetermined pressure, and the embossed material film is peeled off from the embossing roll. After being transferred to the material film, irregularities slightly deformed by an appropriate temperature and tensile force are formed on the material film, and a water-repellent film having high water repellency is obtained.

  The method for producing a water-repellent film according to the present invention includes a step of stopping the conveyance of the material film between the step of performing the embossing, the step of peeling the material film from the embossing roll, and the embossing roll. The method further comprises a step of cooling the surface of the substrate and a step of resuming the conveyance of the embossed material film. According to the method for producing a water-repellent film of the present invention, after embossing is performed, the conveyance of the material film is stopped, the surface of the embossing roll is cooled, and the conveyance of the embossed material film is resumed. Since it did in this way, the optimal temperature at the time of peeling can be implement | achieved and a water-repellent film with high water repellency is obtained.

  Moreover, the manufacturing method of the water-repellent film according to the present invention is characterized in that the cooling temperature of the surface of the embossing roll is 35 ° C. or more and 45 ° C. or less. According to the method for producing a water-repellent film of the present invention, since the cooling temperature of the surface of the embossing roll is set to 35 ° C. or more and 45 ° C. or less, a complicated uneven shape is formed on the material film by pulling with an appropriate force at the time of peeling. Can be given.

  Moreover, the manufacturing method of the water-repellent film according to the present invention is characterized in that the heating temperature of the surface of the embossing roll is 55 ° C. or more and 80 ° C. or less. According to the method for producing a water-repellent film of the present invention, since the heating temperature of the surface of the embossing roll is set to 55 ° C. or higher and 80 ° C. or lower, a water-repellent film having a coarser microstructure on the surface can be produced. .

  In the method for producing a water-repellent film according to the present invention, the heating temperature of the material film is 100 ° C. or more and 250 ° C. or less. According to the method for producing a water-repellent film of the present invention, since the heating temperature of the material film is set to 100 ° C. or more and 250 ° C. or less, the material film can be easily melted and easily embossed without scorching. It becomes.

  Moreover, the manufacturing method of the water-repellent film according to the present invention is characterized in that the unevenness on the surface of the embossing roll is formed by a sandblasting method. According to the method for producing a water-repellent film of the present invention, the irregularities on the surface of the embossing roll are formed by the sandblasting method, so that irregular irregularities suitable for providing the film with water repellency can be given. It becomes possible.

  In the method for producing a water repellent film according to the present invention, the arithmetic average roughness Ra of the surface of the embossing roll is from 0.1 μm to 20.0 μm. According to the method for producing a water-repellent film of the present invention, since the arithmetic average roughness Ra of the surface of the embossing roll is set to 0.1 μm or more and 20.0 μm or less, an uneven shape with an appropriate fine structure is provided on the material film. Is possible.

  According to the present invention, a water-repellent film having sufficient water repellency can be produced.

It is a figure which shows the water-repellent film manufacturing apparatus for implement | achieving the manufacturing method of the water-repellent film which concerns on one Embodiment of this invention. It is a flowchart which shows the manufacturing method of the water repellent film which concerns on one Embodiment of this invention. It is a figure which shows the surface image of the manufactured water-repellent film, and its undulation. It is a graph of the water-repellent property of the manufactured water-repellent film. It is sectional drawing of the state which accommodated the content, when using a water repellent film as a container.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
<1. Configuration of water-repellent film manufacturing apparatus>
FIG. 1 is a view showing a water-repellent film manufacturing apparatus for realizing a method for manufacturing a water-repellent film according to an embodiment of the present invention. In FIG. 1, 1 is a water-repellent film manufacturing apparatus, 2 is a conveyor belt, 3 is a heating unit, 4 is an embossing roll, 5 is a pressure roll, 6 is an embossing unit, 7 is a peeling unit, F is a material film, and F ′ is It is a water repellent film. Further, the downward arrow indicates the conveyance direction of the material film F by the conveyance belt 2, and the right arrow indicates the conveyance direction of the water repellent film F ′ by the conveyance belt 2.

  The conveyance belt 2 is a belt for conveying the material film F to be processed, and is realized by a belt made of a known material. In the present embodiment, a fluorine resin belt is employed. The heating unit 3 is for heating the material film F, and is realized by a known heating mechanism such as a heater.

  The embossing roll 4 is a roll for embossing the material film F by applying pressure between the pressure rolls 5. As the embossing roll 4, various known ones can be used as long as the outer peripheral surface has irregularities for shaping. For example, metals such as copper, aluminum, and stainless steel can be used as the material. Further, the embossing roll itself may be formed with irregularities for shaping directly on the outer peripheral surface, or a flat plate with irregularities for shaping formed around the embossing roll body. Also good.

  In the present embodiment, as the embossing roll 4, an embossing roll body on which unevenness is formed by a known sandblasting method is used which is subjected to chromium (Cr) plating. Since the unevenness is formed using the sand blast method, the unevenness is irregularly formed on the surface. However, the arithmetic average roughness Ra of the surface is adjusted to be 0.1 μm or more and 20.0 μm or less, preferably 0.5 μm or more and 20.0 μm or less, more preferably 5.0 μm or more and 15.0 μm or less. Is done. Any known method other than the sandblasting method may be used as long as irregularities can be irregularly formed with a predetermined arithmetic average roughness Ra. The diameter of the embossing roll 4 is not particularly limited, but in the example of FIG. The embossing roll 4 is a known embossing roll that can be heated and cooled, and the temperature of the embossing roll surface can be adjusted to a set temperature by heating or cooling the liquid flowing inside the embossing roll. Yes. The surface of the embossing roll 4 may be subjected to a peeling treatment with a fluororesin or the like in order to facilitate the peeling of the material film F after the embossing.

  The pressure roll 5 is for applying pressure to the material film F when the embossing roll 4 performs embossing, and is realized by a known pressure roll. In the present embodiment, an elastic body such as rubber is wound around the outer peripheral surface of the roll body. The diameter of the pressure roll 5 is preferably substantially the same as that of the embossing roll 4. In the example of FIG. 1, the same embossing roll 4 having a diameter of 150 mm is used.

  Both the embossing roll 4 and the pressure roll 5 have a rotation shaft at the center, and the rotation shaft can be rotated by a drive mechanism (not shown). In addition, a control mechanism (not shown) controls and drives the drive mechanisms of the embossing roll 4 and the pressure roll 5 so that both have the same peripheral speed. When the diameters of the embossing roll 4 and the pressure roll 5 are the same, the drive mechanisms of the embossing roll 4 and the pressure roll 5 are controlled and driven so as to have the same angular velocity.

  The embossed portion 6 is a portion where the surfaces of the embossing roll 4 and the pressure roll 5 are closest. In the embossed portion 6, embossing is performed on the material film F sandwiched between the embossing roll 4 and the pressure roll 5. The peeling part 7 is a part where the embossed material film F is peeled from the embossing roll 4.

  The material film F is a film that is a material for producing a water-repellent film, and various resin films such as polyethylene, polypropylene, polyester, polycarbonate, and polyurethane can be used.

<2. Manufacturing method of water repellent film>
Next, a method for producing a water repellent film according to this embodiment will be described with reference to the flowchart of FIG. First, the material film F is attached to the conveyance belt 2. Specifically, it is heated and laminated on the material film F. After the material film F is mounted, the water-repellent film manufacturing apparatus 1 is operated. When the water-repellent film manufacturing apparatus 1 starts operation, the heating unit 3 starts heating (step S1). Furthermore, the embossing roll 4 starts heating (step S2). Either step S1 or step S2 may be executed first. What is necessary is just to be performed before the process start of step S3.

  Subsequently, the surface temperature of the material film F reaches a predetermined temperature within a range of 100 ° C. or more and 250 ° C. or less (preferably 150 ° C. or more and 250 ° C. or less) by heating by the heating unit 3, and the surface temperature of the embossing roll 4 is When the temperature reaches a predetermined temperature in the range of 55 ° C. or higher and 80 ° C. or lower (preferably 70 ° C. or higher and 80 ° C. or lower), the conveyance of the material film is started (step S3). Specifically, the rotation of the embossing roll 4, the pressure roll 5 and the conveying roller (not shown) and the driving of the conveying belt 2 are started. Since the surface temperature of the embossing roll 4 is uniformly heated on the surface, the temperature of the embossing part 6 also reaches a predetermined temperature within the range of 55 ° C. or more and 80 ° C. or less.

  When the material film F reaches the embossed portion 6 by driving the conveyor belt 2, the material film F is sandwiched and pressed between the embossing roll 4 and the pressure roll 5 and embossed by the unevenness on the surface of the embossing roll 4 ( Step S4). Unevenness on the surface of the embossing roll 4 is transferred and formed on the surface of the material film F by embossing.

  After the unevenness is formed on the surface of the material film F, the material film F starts to be conveyed before the leading edge of the material film F in the conveying direction reaches the peeling part 7 (step S5). Specifically, the rotation of the embossing roll 4, the pressure roll 5 and the conveying roller and the driving of the conveying belt 2 are stopped. Then, the embossing roll is cooled (step S6). Specifically, a setting instruction is given to the embossing roll 4 so as to reach a predetermined temperature within a range of 35 ° C. or more and 45 ° C. or less, and the temperature adjusting mechanism cools the embossing roll 4 according to this instruction.

  When the surface temperature of the embossing roll 4 falls below a predetermined temperature within the range of 35 ° C. or more and 45 ° C. or less by the temperature adjustment mechanism inside the embossing roll 4, the embossing roll 4, the pressure roll 5, and the conveying roller (not shown) The rotation and driving of the conveyor belt 2 are started again. Since the surface temperature of the embossing roll 4 is uniformly cooled on the surface, the temperature of the peeling portion 7 is also equal to or lower than a predetermined temperature.

  When the embossing roll 4, the pressure roll 5, and the conveying roller (not shown) are rotated and the conveying belt 2 is driven, the material film F having irregularities formed on the surface is peeled from the embossing roll 4 at the peeling portion 7 ( Step S7). Thereby, water-repellent film F 'is obtained. Then, the peeled water-repellent film F ′ is moved and unloaded as the transport belt 2 is driven. By keeping the temperature of the peeling part 7 below a predetermined temperature, an appropriate tensile force is applied to the surface of the material film F at the time of peeling. For this reason, the surface of the water repellent film F ′ is formed with unevenness having a shape different from the unevenness of the embossing roll 4. The water repellent film F ′ thus obtained has a good water repellency.

Next, examples of the present invention will be described.
[Emboss roll surface]
Unevenness was formed on the surface of the embossing roll 4 by a known sandblasting method. When the surface of the obtained embossing roll 4 was measured based on JISB0601: 2001, arithmetic mean roughness Ra was 7.58 micrometer.

  After mounting the embossing roll 4 with the irregularities on the water repellent film production apparatus 1, a water repellent film was produced under the following conditions.

[conditions]
Surface temperature of material film: 250 ° C
Embossing roll surface temperature during embossing: 50 ° C, 77 ° C
Material film transport speed: 1 m / min Pressure when embossing: 0.6 MPa
Embossing roll surface temperature at the time of peeling: 40 ° C

[result]
In the said conditions, the surface temperature of a raw material film is the temperature before reaching the embossed part 6 after the heating by the heating part 3. Moreover, the surface temperature of the embossing roll at the time of embossing respond | corresponds to the temperature of the embossing part 6 of FIG. 1, and the surface temperature of the embossing roll at the time of peeling respond | corresponds to the temperature of the peeling part 7 of FIG. When the surface of the water repellent film produced under the above conditions was measured according to JISB0601: 2001, the arithmetic average roughness Ra was 6.57 μm when the surface temperature of the embossing roll was 50 ° C., and the surface of the embossing roll. When the temperature was 77 ° C., it was 8.49 μm. As for the water repellency with respect to water, when the surface temperature of the embossing roll is 50 ° C., the water droplets are not rounded and the water repellency is low. The water repellency was extremely high. The manufactured water-repellent film has an arithmetic average roughness Ra of 0.1 μm to 20.0 μm, preferably 0.5 μm to 20.0 μm, more preferably 5.0 μm to 15.0 μm. Exhibits high water repellency.

  FIG. 3 is a view showing a surface image of a water-repellent film produced according to the above [Conditions] and its undulation. 3 (a) is a surface image of a water repellent film when the surface temperature of the embossing roll is 77 ° C., and FIG. 3 (b) is a surface image of the water repellent film when the surface temperature of the embossing roll is 50 ° C. FIG. 3C shows the undulations along the line AA in FIG. 3A, and FIG. 3D shows the undulations along the line BB in FIG. 3B. 3 (c) and 3 (d), the unit is μm for both the horizontal axis and the vertical axis. For the convenience of illustration, the horizontal positions in FIGS. 3A and 3C and the horizontal positions in FIGS. 3B and 3D are shifted. For this reason, a horizontally long rectangle on the AA line in FIG. 3A and a horizontally long rectangle on the BB line in FIG. 3B are arranged, respectively, as shown in FIG. 3C and FIG. Corresponding. A vertical thick line in the vicinity of 40 μm in the horizontal axis in FIG. 3C means that it corresponds to a position included in a horizontally long rectangle on the AA line in FIG. 3A, and the horizontal line in FIG. A vertical thick line near the axis of 30 μm means that it corresponds to a position included in a horizontally long rectangle on the line BB in FIG. In FIGS. 3B and 3D, the part surrounded by an ellipse indicates an area where transfer is insufficient.

[Comparative example]
Furthermore, as a comparative example, when the surface temperature of the embossing roll at the time of embossing is 55 ° C., the surface temperature of the material film is 80 ° C., 120 ° C., 175 ° C., 230 ° C., 300 ° C. Tried to manufacture. A graph of the water repellency characteristics of the produced water repellent film is shown in FIG. In FIG. 4, the horizontal axis represents the surface temperature of the embossing roll during embossing (the temperature of the embossed portion 6), and the vertical axis represents the surface temperature of the material film.

  Moreover, in FIG. 4, water repellency is evaluated in three stages, ◯ indicates that the water droplet is rounded and rolls, indicating that the water repellency is extremely high, and Δ indicates that the water droplet does not roll but is rounded. , Indicating that the water repellency is high, and x indicates that the water droplet is not rounded and the water repellency is low.

  From the results shown in FIG. 4, when the surface temperature of the embossing roll during embossing is 55 ° C. or more and 80 ° C. or less, and the surface temperature of the material film is 120 ° C. or more and 250 ° C. or less, the water repellency increases. I understand that. In FIG. 4, a shaded rectangular area indicates a water-repellent expression area having high water repellency. In particular, when the surface temperature of the embossing roll during embossing is 75 ° C. or higher and the surface temperature of the material film is 170 ° C. or higher, the water repellency is extremely high.

  When the water-repellent film prepared as described above is used as a container, FIG. In FIG. 5, the contents are water-based. Actually, the water-repellent film produced according to the present invention has irregular irregularities, but in the example of FIG. Show. As shown in FIG. 5, the surface arithmetic mean roughness Ra is 0.5 μm or more and 20.0 μm or less, more preferably 5.0 μm or more and 15.0 μm or less. By forming the layer, a lotus effect is exhibited. For this reason, the degree to which water-based contents adhere to the water-repellent film can be reduced.

  The preferred embodiments and examples of the present invention have been described above. However, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made. For example, in the above embodiment and examples, after the embossing (step S4), the conveyance of the material film is stopped (step S5), and the embossing roll is cooled (step S6). In the state where the embossing roll is heated, the water repellent film having a certain degree of water repellency is obtained even when the embossing roll is continuously transported at 1 m / min without stopping the transport of the material film and without cooling the embossing roll. Can be obtained.

  The water-repellent film produced by the method for producing a water-repellent film according to the present invention can be used as a container for housing various contents including food.

DESCRIPTION OF SYMBOLS 1 ... Water-repellent film manufacturing apparatus 2 ... Conveyor belt 3 ... Heating part 4 ... Embossing roll 5 ... Pressure roll 6 ... Embossing part 7 ... Peeling part F ... Material Film F '... Water-repellent film

Claims (7)

Heating the material film;
Heating the surface of the embossing roll;
Transporting the material film at a predetermined speed and transporting it between an embossing roll and a pressure roll;
A step of embossing the surface of the heated material film at a predetermined pressure with an embossing roll and a pressure roll;
Peeling the material film subjected to the embossing from the embossing roll;
A method for producing a water-repellent film, comprising: Between the step of performing the embossing and the step of peeling the material film from the embossing roll,
A process of stopping the conveyance of the material film;
Cooling the surface of the embossing roll;
A process of resuming conveyance of the embossed material film;
The method for producing a water repellent film according to claim 1, further comprising:   The method for producing a water-repellent film according to claim 2, wherein the cooling temperature of the surface of the embossing roll is 35 ° C. or higher and 45 ° C. or lower.   The method for producing a water repellent film according to any one of claims 1 to 3, wherein the heating temperature of the surface of the embossing roll is 55 ° C or higher and 80 ° C or lower.   The method for producing a water-repellent film according to any one of claims 1 to 4, wherein the heating temperature of the material film is 100 ° C or higher and 250 ° C or lower.   6. The method for producing a water repellent film according to claim 1, wherein the unevenness of the surface of the embossing roll is formed by a sandblasting method.   The method for producing a water repellent film according to any one of claims 1 to 6, wherein an arithmetic average roughness Ra of the surface of the embossing roll is 0.1 µm or more and 20.0 µm or less.