Method for manufacturing resin film and metal mold

Abstract

To provide a method of manufacturing a resin film capable of providing the resin film with water repellency, hydrophilicity and / or antiviral properties by providing at least a part of surface of the resin film with a roughened shape.SOLUTION: A method of manufacturing a resin film having a roughened shape at least on a part of a surface of the resin film has a transfer step of transferring a roughened shape of a roughened surface to the resin film by bringing a metal mold having the roughened surface at least on a part of the surface into contact with the resin film. The roughened surface of the metal mold has a developed area ratio (Sdr) measured in accordance with ISO 25178 of 0.094 to 0.4285, and a root mean square gradient (Sdq) of 0.14 to 0.99.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a resin film and a metal mold.

Background Art

[0002] Resin films are required to have many properties depending on their applications. For example, resin films with high water repellency or hydrophilicity have various applications. In recent years, in order to prevent the infection of COVID-19, so-called novel coronavirus infection and seasonal influenza, it may be required to impart antiviral properties to the surface of resin films that are touched by hand.

[0003] Patent Document 1 below describes an antiviral surface treatment method in which a projection treatment (hereinafter also referred to as "blasting treatment") of projecting a shot material onto the surface of a member is performed to randomly form innumerable minute irregularities having a specific uneven pitch width and a width of the depth of the recesses, thereby imparting an antiviral action to the surface of the member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One criterion for evaluating antiviral properties is the "antiviral activity value." In the technology described in Patent Document 1, the comparison material (stainless steel plate) does not exhibit antiviral properties, but when an antiviral surface treatment method is applied, the antiviral activity value shows 0.4 to 0.7 after 24 hours at 25°C. However, as a result of the inventors' investigation, it was found that, because blast treatment involves projecting shot material onto the surface of the material, it is only possible to impart a convex shape toward the back surface of the material. Therefore, the antiviral properties obtained by the technology described in Patent Document 1 are insufficient, and further improvement of antiviral properties is necessary.

[0006] Furthermore, Patent Document 1 does not describe or suggest any method for imparting water-repellent or hydrophilic properties to the resin film.

[0007] In view of the above, the present invention aims to provide a method for manufacturing a resin film that can impart water repellency, hydrophilicity, and / or antiviral properties to a resin film by imparting a roughened shape to at least a portion of the surface of the resin film. Furthermore, the present invention aims to provide a metal mold for forming a roughened shape to at least a portion of the surface of a resin film, which can impart water repellency, hydrophilicity, and / or antiviral properties to a resin film by imparting a roughened shape to at least a portion of the surface of the resin film. [Means for solving the problem]

[0008] The above problems can be solved by the following configuration. The present invention relates to a method for manufacturing a resin film having a roughened shape on at least a part of the surface of the resin film, comprising a transfer step of transferring the roughened shape of the roughened surface to the resin film by bringing a metal mold having a roughened surface on at least a part of its surface into contact with the resin film, wherein the roughened surface of the metal mold has an unfolded area ratio (Sdr) of 0.005 to 0.5 and a root mean square slope (Sdq) of 0.1 to 1.5 as measured in accordance with ISO 25178.

[0009] In the above resin film manufacturing method (1), a resin film manufacturing method (2) is preferred in which, in the transfer step, water repellency is imparted to at least a part of the surface of the resin film.

[0010] In the above resin film manufacturing method (2), a resin film manufacturing method (3) is preferred in which the contact angle of the resin film with water before the transfer step is 90° or more.

[0011] In the above resin film manufacturing method (1), a resin film manufacturing method (4) is preferred in which hydrophilicity is imparted to at least a part of the surface of the resin film in the transfer step.

[0012] In the above resin film manufacturing method (4), a resin film manufacturing method (5) is preferred in which the contact angle of the resin film with water before the transfer step is 90° or less.

[0013] In the above resin film manufacturing method (1), a resin film manufacturing method (6) is preferred in which, in the transfer step, antiviral properties are imparted to at least a part of the surface of the resin film.

[0014] The present invention also relates to a metal mold for forming a roughened shape on at least a part of the surface of a resin film, wherein the metal mold has a roughened surface on at least a part of its surface for transferring the roughened shape to the resin film, and the roughened surface is characterized in that the developed area ratio (Sdr) measured in accordance with ISO25178 is 0.005 to 0.5 and the root mean square slope (Sdq) is 0.1 to 1.5. [Effects of the Invention]

[0015] In the method for manufacturing a resin film according to the present invention, there is a transfer step of transferring the roughened shape of the roughened surface to the resin film by bringing a metal mold having a roughened surface into contact with the resin film at least on a part of the surface. Here, in the method for manufacturing a resin film according to the present invention, the roughened surface of the metal mold is designed such that the developed area ratio (Sdr) measured in accordance with ISO25178 is 0.005 to 0.5 and the root mean square slope (Sdq) is 0.1 to 1.5. Thereby, water repellency, hydrophilicity and / or antiviral properties can be imparted to the resin film.

Brief Description of the Drawings

[0016] [Figure 1] Scanning electron micrograph (1500 times magnification) of the surface of an untreated copper plate having no roughened shape. [Figure 2] Scanning electron micrograph (magnification 5000 times) of the surface of an untreated copper plate having no roughened shape. [Figure 3] Scanning electron micrograph (1500 times magnification) of the surface of a copper plate having a roughened shape A (metal mold A). [Figure 4] Scanning electron micrograph (magnification 5000 times) of the surface of a copper plate having a roughened shape A (metal mold A). [Figure 5] Scanning electron micrograph (1500 times magnification) of the surface of a copper plate having a roughened shape B (metal mold B). [Figure 6] Scanning electron micrograph (magnification 5000 times) of the surface of a copper plate having a roughened shape B (metal mold B). [Figure 7] Scanning electron micrograph (1500 times magnification) of the surface of a copper plate having a roughened shape C (metal mold C). [Figure 8] Scanning electron micrograph (magnification 5000 times) of the surface of a copper plate having a roughened shape C (metal mold C). [Figure 9] Scanning electron micrograph (1500 times magnification) of the surface of a copper plate having a roughened shape D (metal mold D). [Figure 10] Scanning electron micrograph (magnification 5000 times) of the surface of a copper plate having a roughened shape D (metal mold D). [Figure 11] Scanning electron micrograph (1500x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape A [Figure 12] Scanning electron micrograph (5000x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape A [Figure 13] Scanning electron micrograph (1500x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape B [Figure 14] Scanning electron micrograph (5000x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape B [Figure 15] Scanning electron micrograph (1500x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape C [Figure 16] Scanning electron micrograph (5000x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape C [Figure 17] Scanning electron micrograph (1500x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape D [Figure 18] Scanning electron micrograph (5000x magnification) of the surface of a resin film (PP film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape D [Figure 19] Scanning electron micrograph (1500x magnification) of the surface of a resin film (Acryl film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape A [Figure 20] Scanning electron micrograph (5000x magnification) of the surface of a resin film (Acryl film) on which a transfer process was carried out using a copper plate (metal mold A) having a roughened shape A [Figure 21]Scanning electron microscope image (magnification 1500x) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold B) having a roughened shape B. [Figure 22] Scanning electron microscope image (magnification 5000x) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold B) having a roughened shape B. [Figure 23] Scanning electron microscope image (magnification 1500x) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold C) having a roughened shape C. [Figure 24] Scanning electron microscope image (magnification 5000x) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold C) having a roughened shape C. [Figure 25] Scanning electron microscope image (magnification 1500x) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold D) having a roughened shape D. [Figure 26] Scanning electron microscope image (magnification 5000x) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold D) having a roughened shape D. [Modes for carrying out the invention]

[0017] The present invention provides a method for manufacturing a resin film that exhibits water repellency, hydrophilicity, and / or antiviral properties by having a roughened surface on at least a portion of its surface. The method for manufacturing a resin film according to the present invention includes a transfer step of transferring the roughened surface shape to a resin film by bringing a metal mold having a roughened surface on at least a portion of its surface into contact with the resin film. The roughened surface of the metal mold used in the transfer step has an unfolded area ratio (Sdr) of 0.005 to 0.5 and a root mean square slope (Sdq) of 0.1 to 1.5, as measured in accordance with ISO 25178.

[0018] In the method for producing a resin film according to the present invention, various types of resin films can be used as raw materials to advantageously impart desired water repellency, hydrophilicity, and / or antiviral properties. For example, when imparting water repellency to at least a portion of the surface of a resin film, it is preferable to use a resin film in which the contact angle with water of the resin film is 90° or more as a raw material, and such a resin film is, for example, a polypropylene (PP) film. Also, for example, when imparting hydrophilicity to at least a portion of the surface of a resin film, it is preferable to use a resin film in which the contact angle with water of the resin film is 90° or less as a raw material, and such a resin film is, for example, a poly(meth)acrylic film.

[0019] Furthermore, when imparting antiviral properties to at least a portion of the surface of a resin film, for example, suitable resin films for use as raw materials include thermoplastic resins, thermosetting resins, or UV-curable resins. Examples of thermoplastic resins include general-purpose plastics such as polypropylene, polyacrylic resin, and ABS resin; engineering plastics such as nylon 6, nylon 66, polyacetal, polycarbonate, polybutylene terephthalate, and modified polyphenylene ether; and super engineering plastics such as polyphenylene ether, liquid crystal polymer, and polyetherimide. Examples of thermosetting resins include phenolic resin, urea resin, melamine resin, epoxy resin, unsaturated polyester resin, polyurethane resin, diallyl phthalate resin, silicone resin, and alkyd resin. Examples of UV-curable resins include acrylic resins and epoxy resins.

[0020] Next, we will explain the metal molds used in the transfer process.

[0021] The metal mold used in the transfer step of the resin film manufacturing method according to the present invention has a roughened surface on at least a part of its surface. The specific properties of the roughened surface will be described separately. Examples of metal components constituting the metal mold include aluminum, aluminum alloys, copper, copper alloys, nickel, nickel alloys, stainless steel, titanium, titanium alloys, iron, or iron alloys. Among these, in the present invention, it is preferable to use aluminum, aluminum alloys, copper, or copper alloys as the metal component, and it is more preferable to use copper or copper alloys. The shape and size of the metal mold can be appropriately designed according to the application of the resin film to which water repellency, hydrophilicity, and / or antiviral properties are to be imparted.

[0022] A step in forming a roughened surface on at least part or all of the surface of a metal mold is, for example, a roughening treatment step in which a micro-etching agent is brought into contact with the surface of a metal member to form a roughened surface on the surface of the metal member.

[0023] Examples of micro-etching agents that can be used in the roughening process include organic acid-based micro-etching agents, inorganic acid-based micro-etching agents, alkaline-based micro-etching agents, and hydrogen peroxide-based micro-etching agents.

[0024] Examples of organic acid-based micro-etching agents include micro-etching agents consisting of aqueous solutions containing organic acids, metal ion sources, halide ion sources, etc.

[0025] Examples of inorganic acid-based micro-etching agents include micro-etching agents consisting of an acidic aqueous solution containing an inorganic acid, a metal ion source, a halide ion source, and the like.

[0026] Examples of alkaline micro-etching agents include those consisting of an aqueous solution containing an alkali source, an amphoteric metal ion source, nitrate ions, a thio compound, and the like.

[0027] Examples of hydrogen peroxide-based micro-etching agents include micro-etching agents consisting of aqueous solutions mainly composed of hydrogen peroxide and sulfuric acid.

[0028] The roughening process may be carried out in one step, but it is preferable to carry it out in two steps in order to obtain more favorable properties of the roughened surface of the metal mold to be manufactured, and it is particularly preferable to carry it out in three steps: a pre-treatment step, a main treatment step, and a post-treatment step. An embodiment of the roughening process carried out in three steps will be described below.

[0029] In the pretreatment step, examples include immersing at least the surface to be treated of the metal component in an alkaline soft etching agent, such as a hydrogen peroxide-based soft etching agent consisting of an aqueous solution mainly composed of dilute nitric acid, hydrogen peroxide, and sulfuric acid, or an aqueous solution containing the above-mentioned alkali source, amphoteric metal ion source, nitrate ions, thio compounds, etc. Examples of treatment temperatures include 15 to 40°C, and treatment times include 3 seconds to 10 minutes.

[0030] This processing step may involve immersing at least the surface of the metal component in the above-mentioned organic acid-based micro-etching agent, inorganic acid-based micro-etching agent, alkaline-based micro-etching agent, or hydrogen peroxide-based micro-etching agent. Examples of processing temperatures include 10-40°C, and processing times may range from 5 seconds to 10 minutes.

[0031] In the post-treatment step, an example is immersing at least the treated surface of the metal component in dilute nitric acid. Examples of treatment temperatures include 15-40°C and treatment times of approximately 3-40 seconds.

[0032] After the roughening process, a roughened surface can be formed on the surface of the metal member, having an expanded area ratio (Sdr) of 0.005 to 0.5 and a root mean square slope (Sdq) of 0.1 to 1.5, as measured in accordance with ISO 25178. The expanded area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface formed on the surface of the metal member can be adjusted by changing the type of micro-etching agent in the roughening process, as well as the processing time and / or temperature of the roughening process (step 1, step 2, and / or step 3), to arbitrary conditions. To impart a higher level of water repellency, hydrophilicity, and / or antiviral properties to the resin film, it is more preferable that the roughened surface of the metal mold has an expanded area ratio (Sdr) of 0.0094 to 0.4285 and a root mean square slope (Sdq) of 0.14 to 0.99, as measured in accordance with ISO 25178.

[0033] Next, the transfer step of the resin film manufacturing method according to the present invention will be described. In the transfer step, the roughened shape of the roughened surface is transferred to the resin film by bringing a metal mold having a roughened surface on at least a part of its surface into contact with the resin film.

[0034] One method for transferring the roughened shape of the roughened surface of a metal mold to a resin film by bringing the metal mold into contact with the resin film is to overlap the roughened surface of the metal mold with a surface of the resin film that has been treated with a water-repellent, hydrophilic, and / or antiviral treatment, and then heat-press it using a press machine. On the other hand, one method for transferring the roughened shape of the roughened surface of a metal mold to the surface of a thermosetting resin or UV-curable resin is to form a mold that includes at least the roughened surface of the metal mold, pour in the raw material components of a thermosetting resin or UV-curable resin into it, cure it, and then demold the resin film, thereby transferring the roughened shape formed on the surface of the metal member to the surface of the thermosetting resin or UV-curable resin.

[0035] After the transfer process, a complex roughened surface is formed on the resin film. Specific examples of the complex roughened surface formed on the resin component after the transfer process will be described later.

[0036] The method for manufacturing a resin film according to the present invention can impart water repellency, hydrophilicity, and / or antiviral properties to the resin film. In the present invention, the water repellency of the resin film is evaluated by the contact angle with water. Specifically, in the present invention, if the contact angle is 10° or more higher than the contact angle of the untreated resin film before the transfer process, water repellency is considered to have been imparted. In the present invention, when a resin film with a contact angle with water exceeding 110° is manufactured, such a resin film is preferable because it has particularly excellent water repellency. Furthermore, in the present invention, the water repellency of the resin film is also evaluated by the contact angle with water. If the contact angle is 10° or more lower than the contact angle of the untreated resin film before the transfer process, water repellency is considered to have been imparted. In the present invention, when a resin film with a contact angle with water of 70° or less is manufactured, such a resin film is preferable because it has particularly excellent hydrophilicity.

[0037] Furthermore, the resin film manufacturing method according to the present invention can produce a resin film with excellent antiviral properties. The antiviral activity value, which indicates the degree of antiviral properties, can be calculated using the following formula, with reference to JIS R1756:2020 (Visible light-responsive photocatalyst, antiviral, film adhesion method). V D =Log(B D )-Log(C D ) (1) In the above equation (1), V D The values ​​shown are antiviral activity, D for dark conditions, B for unprocessed samples, and C for processed samples.

[0038] As described above, the resin film manufacturing method according to the present invention makes it possible to manufacture resin films with excellent antiviral properties. Therefore, the resin film manufacturing method according to the present invention is also useful as a treatment method to impart antiviral properties to resin films used in home appliances, housing building materials / equipment, toilet-related facilities / supplies, kitchen-related facilities / supplies, bathroom-related facilities / supplies, office equipment / supplies, printing (printed materials, laminated products and paper), transportation equipment, industrial equipment / industrial supplies (films, packaging materials for food etc., packing materials etc.), medical / nursing / health, communication-related / accessories, pet supplies, daily necessities (shoes, cleaning supplies, cosmetics etc.), and the like. [Examples]

[0039] An example of an embodiment of the present invention is described below, but the present invention is not limited in any way to this description.

[0040] <Method for measuring the undeveloped area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface of a metal mold> Using a Lasertec confocal microscope (Hybrid Laser Microscope OPTELICS HYBRID+), the developed area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface of metal molds were measured in accordance with ISO 25178. During the measurements, cutoff values ​​were established using an S filter (0.0025 mm) and an L filter (0.08 mm).

[0041] [Examples of metal mold manufacturing (examples of roughened surface formation)] First, an untreated copper plate without a roughened surface was prepared. Figure 1 shows a scanning electron microscope image (magnification 1500x) of the surface of the untreated copper plate without a roughened surface, and Figure 2 shows a scanning electron microscope image (magnification 5000x) of the surface of the untreated copper plate without a roughened surface. By applying a roughening process to the untreated copper plate, metal molds A, B, C, and D were manufactured, each having a roughened surface with roughened surface shape A, roughened surface B, C, and D, respectively, at least on a portion of the surface. Figure 3 shows a scanning electron microscope image (magnification 1500x) of the surface of a copper plate (metal mold A) with roughened shape A, Figure 4 shows a scanning electron microscope image (magnification 5000x) of the surface of a copper plate (metal mold A) with roughened shape A, Figure 5 shows a scanning electron microscope image (magnification 1500x) of the surface of a copper plate (metal mold B) with roughened shape B, Figure 6 shows a scanning electron microscope image (magnification 5000x) of the surface of a copper plate (metal mold B) with roughened shape B, and Figure 7 shows roughened Figure 8 shows a scanning electron microscope image (magnification 1500x) of the surface of a copper plate (metal mold C) having roughened shape C, Figure 9 shows a scanning electron microscope image (magnification 5000x) of the surface of a copper plate (metal mold D) having roughened shape D, and Figure 10 shows a scanning electron microscope image (magnification 5000x) of the surface of a copper plate (metal mold D) having roughened shape D. The following describes the roughening process applied to metal molds A, B, C, and D.

[0042] [Roughening process for metal mold A] A roughening process (three steps: pre-treatment step, main treatment step, and post-treatment step) was performed on an unused copper plate (100mm x 100mm x t1.3mm) under the following conditions. The conditions for each step are shown below. (Pre-processing step) The surface of the copper plate to be treated was sprayed with a sulfuric acid / hydrogen peroxide-based soft etching agent. Treatment temperature: 25°C. Treatment time: 20 seconds. (This processing step) Following pretreatment, the surface of the copper plate to be treated is sprayed with an inorganic acid-based micro-etching agent (a micro-etching agent consisting of an aqueous solution containing inorganic acid, a metal ion source, a halide ion source, etc.). Treatment temperature: 30°C. Treatment time: 50 seconds. (Post-processing step) Following this treatment, the surface of the copper plate to be treated was sprayed with dilute hydrochloric acid. Treatment temperature: 25°C. Treatment time: 15 seconds. Table 1 shows the ratio of the roughened surface area (Sdr) and the root mean square slope (Sdq) of the metal mold A obtained after the roughening process.

[0043] [Roughening process for metal mold B] A roughening process (three steps: pre-treatment step, main treatment step, and post-treatment step) was performed on an unused copper plate (100mm x 100mm x t1.3mm) under the following conditions. The conditions for each step are shown below. (Pre-processing step) The surface of the copper plate to be treated was sprayed with a sulfuric acid / hydrogen peroxide-based soft etching agent. Treatment temperature: 25°C. Treatment time: 20 seconds. (This processing step) Following pretreatment, the surface of the copper plate to be treated is sprayed with an inorganic acid-based micro-etching agent (a micro-etching agent consisting of an aqueous solution containing inorganic acid, a metal ion source, a halide ion source, etc.). Treatment temperature: 30°C. Treatment time: 50 seconds. (Post-processing step) Following this treatment, the surface of the copper plate to be treated was sprayed with dilute hydrochloric acid. Treatment temperature: 25°C. Treatment time: 15 seconds. Table 1 shows the ratio of the roughened surface area (Sdr) and the root mean square slope (Sdq) of the metal mold B obtained after the roughening process.

[0044] [Roughening process for metal mold C] A roughening process (three steps: pre-treatment step, main treatment step, and post-treatment step) was performed on an unused copper plate (100mm x 100mm x t1.3mm) under the following conditions. The conditions for each step are shown below. (This processing step) Following the pretreatment, the surface of the copper plate to be treated was sprayed with a sulfuric acid / hydrogen peroxide-based micro-etching agent. Treatment temperature: 30°C. Treatment time: 50 seconds. Table 1 shows the ratio of the roughened surface area (Sdr) and the root mean square slope (Sdq) of the metal mold C obtained after the roughening process.

[0045] [Roughening process for metal mold D] A roughening process (three steps: pre-treatment step, main treatment step, and post-treatment step) was performed on an unused copper plate (100mm x 100mm x t1.3mm) under the following conditions. The conditions for each step are shown below. (Pre-processing step) The surface of the copper plate to be treated was sprayed with a sulfuric acid-based soft etching agent. Treatment temperature: 25°C. Treatment time: 20 seconds. (This processing step) Following pretreatment, the surface of the copper plate to be treated is sprayed with an organic acid-based micro-etching agent (a micro-etching agent consisting of an aqueous solution containing organic acid, metal ion source, halide ion source, etc.). Treatment temperature: 30°C. Treatment time: 50 seconds. (Post-processing step) Following this treatment, the surface of the copper plate to be treated was sprayed with dilute hydrochloric acid. Treatment temperature: 25°C. Treatment time: 15 seconds. Table 1 shows the ratio of the roughened surface area (Sdr) and the root mean square slope (Sdq) of the metal mold D obtained after the roughening process.

[0046] [Table 1]

[0047] <Method for measuring the contact angle of resin film with water> The contact angle of the resin film with water was measured under the following conditions. Measuring equipment; Kyowa Interface Science automatic contact angle meter (DM-501) Measurement conditions; Measurement solvent: DI water Measurement method: Contact angle immediately after droplet application Volume: 2.0 μL Analysis method: Droplet method, θ / 2 method

[0048] [Transfer process of resin film (water-repellent properties)] Polypropylene film (PP film) was prepared as the resin film. The contact angle of the untreated PP film before the transfer process was 96°. The transfer process was carried out on the untreated PP film using the following method. The roughened surfaces of metal molds A, B, C, and D were placed on top of the surface of the untreated polypropylene film (PP film) that was to be treated with a water-repellent coating before the transfer process, and the roughened shapes of metal molds A, B, C, and D were transferred to the untreated polypropylene film (PP film) by hot pressing using a press machine. Table 4 shows the hot pressing conditions.

[0049] Example 1 A resin film (PP film) according to Example 1 was manufactured by performing the above transfer process using metal mold A. Figure 11 shows a scanning electron microscope image (magnification 1500x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold A) having roughened shape A, and Figure 12 shows a scanning electron microscope image (magnification 5000x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold A) having roughened shape A. The contact angle of the resin film (PP film) obtained after the transfer process was 116°, indicating high water repellency.

[0050] Example 2 A resin film (PP film) according to Example 2 was manufactured by performing the above transfer process using metal mold B. Figure 13 shows a scanning electron microscope image (magnification 1500x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold B) having roughened shape B, and Figure 14 shows a scanning electron microscope image (magnification 5000x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold B) having roughened shape B. The contact angle of the resin film (PP film) obtained after the transfer process was 118°, indicating high water repellency.

[0051] Example 3 A resin film (PP film) according to Example 3 was manufactured by performing the above transfer process using a metal mold C. Figure 15 shows a scanning electron microscope image (magnification 1500x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold C) having a roughened shape C, and Figure 16 shows a scanning electron microscope image (magnification 5000x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold C) having a roughened shape C. The contact angle of the resin film (PP film) obtained after the transfer process was 124°, indicating high water repellency.

[0052] Example 4 A resin film (PP film) according to Example 4 was manufactured by performing the above transfer process using metal mold D. Figure 17 shows a scanning electron microscope image (magnification 1500x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold D) having a roughened shape D, and Figure 18 shows a scanning electron microscope image (magnification 5000x) of the surface of the resin film (PP film) after performing the transfer process using a copper plate (metal mold A) having a roughened shape D. The resin film (PP film) obtained after the transfer process showed a contact angle exceeding 140°, indicating high water repellency.

[0053] Table 2 shows the contact angles of the untreated PP film before the transfer process (Comparative Example 1) and the contact angles of the PP films after the transfer process in Examples 1 to 4. In all of Examples 1 to 4, the contact angle of the PP film increased by 10° or more, indicating that excellent water repellency was imparted.

[0054] [Table 2]

[0055] [Transfer process of resin film (hydrophilicity imparting)] A poly(meth)acrylic film (Acryl film) was prepared as the resin film. The contact angle of the untreated Acryl film before the transfer process was 84°. The transfer process was carried out on the untreated Acryl film using the following method. The Acryl raw material components were poured into the roughened surfaces of metal molds A, B, C, and D, and after UV curing, the resin film was demolded to produce a film with the roughened shapes of metal molds A, B, C, and D transferred onto it. Table 4 shows the hot pressing conditions.

[0056] Example 5 A resin film (Acryl film) according to Example 5 was manufactured by performing the above transfer process using metal mold A. Figure 19 shows a scanning electron microscope image (magnification 1500x) of the surface of the resin film (Acryl film) after performing the transfer process using a copper plate (metal mold A) having roughened shape A, and Figure 20 shows a scanning electron microscope image (magnification 5000x) of the surface of the resin film (Acryl film) after performing the transfer process using a copper plate (metal mold A) having roughened shape A. The contact angle of the resin film (Acryl film) obtained after the transfer process was 65°, indicating high hydrophilicity.

[0057] Example 6 A resin film (Acryl film) according to Example 6 was manufactured by performing the above transfer process using metal mold B. Figure 21 shows a scanning electron microscope image (magnification 1500x) of the surface of the resin film (Acryl film) after performing the transfer process using a copper plate (metal mold B) having roughened shape B, and Figure 22 shows a scanning electron microscope image (magnification 5000x) of the surface of the resin film (Acryl film) after performing the transfer process using a copper plate (metal mold B) having roughened shape B. The contact angle of the resin film (Acryl film) obtained after the transfer process was 46°, indicating high hydrophilicity.

[0058] Table 3 shows the contact angles of the untreated Acryl film before the transfer process (Comparative Example 2) and the contact angles of the Acryl films after the transfer process in Examples 5 and 6. In all of Examples 5 and 6, the contact angle of the Acryl film was lowered by 10° or more, indicating that excellent hydrophilicity was imparted.

[0059] [Table 3]

[0060] [Transfer process of resin film (imparting antiviral properties)] A transfer process was carried out in which the roughened surfaces of metal molds A, B, C, and D were superimposed on the antiviral treated surface of an untreated resin film (polypropylene film (PP film) and poly(meth)acrylic film (Acryl film)) before the transfer process, and the roughened shapes of metal molds A, B, C, and D were transferred to the untreated resin film (polypropylene film (PP film) and poly(meth)acrylic film (Acryl film)) by hot pressing using a press machine. Table 4 shows the hot pressing conditions.

[0061] [Table 4]

[0062] Examples 7-8 By performing the above transfer process using metal mold B, the resin films (PP films) according to Examples 7 and 8 were manufactured. Example 9 By performing the above transfer process using a metal mold C, a resin film (PP film) according to Example 9 was manufactured. Examples 10-11 By performing the above transfer process using metal mold D, the resin films (PP films) according to Examples 10-11 were manufactured.

[0063] Examples 12-13 By performing the above transfer process using metal mold A, resin films (Acryl films) according to Examples 12-13 were manufactured. Examples 14-15 By performing the above transfer process using metal mold B, resin films (Acryl films) according to Examples 14-15 were manufactured. Examples 16-17 By performing the above transfer process using a metal mold C, resin films (Acryl films) according to Examples 16-17 were manufactured. Example 18 By performing the above transfer process using metal mold D, a resin film (Acryl film) according to Example 18 was manufactured.

[0064] <Antiviral activity evaluation> Using Ref.(-) (glass plate) as an unprocessed product, the antiviral properties of the resin films (polypropylene film (PP film) and poly(meth)acrylic film (Acryl film)) manufactured in Examples 7 to 18 were evaluated under the following conditions. [Test Standards] Based on JIS R1756:2020 (Visible light-responsive photocatalyst, antiviral, film adhesion method). [Unprocessed product name] Ref. (-) (glass plate) [Test product name] Resin films manufactured in Examples 7-18 (polypropylene film (PP film) and poly(meth)acrylic film (Acryl film)) [Size of test samples (PP film and Acryl film)] 50mm x 50mm x t ≤ 1mm [n number] n=1 [Test phage] • Bacteriophage Qβ (NBRC 20012) [Host: Escherichia coli (NBRC 106373)]; Results are shown in Tables 5 and 7. • Bacteriophage φ6 (NBRC 105899, non-JIS standard) [host: Pseudomonas syringae (NBRC 14084)]; results are shown in Tables 6 and 8. [Diluted test phage] 1 / 500NB [Sterilization of test samples] Sterilization with UV254nm (15 minutes on each side) [Operating conditions] Temperature 25°C, dark place, operating time 0 hours, 8 hours [Adhesive film] Polypropylene film (VF-10, KOKUYO), 40mm x 40mm

[0065] [Table 5]

[0066] As shown in Table 5, the PP films obtained in Examples 7, 9, and 10 showed a significant decrease in infectivity titer against bacteriophage Qβ (norovirus surrogate) after 8 hours in the dark at 25°C. Furthermore, the antiviral activity value also increased after 8 hours in the dark at 25°C. These results indicate that the PP films transferred using metal molds B, C, and D exhibit remarkable antiviral properties due to the formation of highly complex roughened surfaces on the PP film.

[0067] [Table 6]

[0068] As shown in Table 6, the PP films obtained in Examples 8 and 11 showed a significant decrease in infectivity against bacteriophage φ6 (influenza virus, COVID-19 surrogate) after 8 hours in the dark at 25°C. Furthermore, the antiviral activity also increased after 8 hours in the dark at 25°C. These results indicate that the PP films transferred using metal molds B and D exhibit remarkable antiviral properties due to the formation of a highly complex roughened surface pattern on the PP film.

[0069] [Table 7]

[0070] As shown in Table 7, the Acryl films obtained in Examples 12, 14, and 16 showed a significant decrease in infectivity against bacteriophage Qβ (norovirus surrogate) after 8 hours in the dark at 25°C. Furthermore, the antiviral activity also increased after 8 hours in the dark at 25°C. These results suggest that the Acryl films produced by the transfer process using metal molds A, B, and C exhibit remarkable antiviral effects due to the formation of a highly complex roughened surface pattern on the Acryl film.

[0071] [Table 8]

[0072] As shown in Table 8, the Acryl films obtained in Examples 13, 15, 17, and 18 showed a significant decrease in infectivity against bacteriophage φ6 (influenza virus, COVID-19 surrogate) after 8 hours in the dark at 25°C. Furthermore, the antiviral activity also increased after 8 hours in the dark at 25°C. These results suggest that the Acryl films produced by the transfer process using metal molds A, B, C, and D exhibit remarkable antiviral effects due to the formation of a highly complex roughened surface pattern on the Acryl film.

Claims

1. A method for manufacturing a resin film having a roughened surface on at least a portion of the surface of the resin film, The process includes a transfer step of transferring the roughened shape of a metal mold having a roughened surface on at least a portion of its surface to the resin film by bringing the metal mold into contact with the resin film. The roughened surface of the metal mold has an undeveloped area ratio (Sdr) of 0.005 to 0.5 and a root mean square slope (Sdq) of 0.1 to 1.5, as measured in accordance with ISO 25178. A method for manufacturing a resin film, characterized in that the metal member constituting the metal mold is copper or a copper alloy.

2. The method for manufacturing a resin film according to claim 1, wherein, in the transfer step, water repellency is imparted to at least a part of the surface of the resin film.

3. The method for manufacturing a resin film according to claim 2, wherein the contact angle of the resin film with water before the transfer step is 90° or more.

4. The method for manufacturing a resin film according to claim 1, wherein, in the transfer step, hydrophilicity is imparted to at least a part of the surface of the resin film.

5. The method for manufacturing a resin film according to claim 4, wherein the contact angle of the resin film with water before the transfer step is 90° or less.

6. The method for producing a resin film according to claim 1, wherein in the transfer step, antiviral properties are imparted to at least a part of the surface of the resin film.

7. A metal mold for forming a roughened shape on at least a portion of the surface of a resin film, wherein the earlier metal mold has a roughened surface on at least a portion of its surface for transferring the roughened shape to the resin film, The roughened surface has an unfolded area ratio (Sdr) of 0.005 to 0.5, measured in accordance with ISO 25178, and a root mean square slope (Sdq) of 0.1 to 1.

5. A metal mold characterized in that the metal members constituting the metal mold are copper or a copper alloy.

Images