Laser processing method for metal plates and method for manufacturing metal plates

Abstract

The objective is to provide a laser processing method and a method for manufacturing a metal plate that, regarding laser-processed films, does not peel off due to gas jetting during laser processing and has excellent peelability from the metal plate after laser processing. [Solution] A laser processing method or manufacturing method for a metal plate, comprising the steps of: bonding a laser-processed film having a light-absorbing substrate and an adhesive layer onto one surface of a metal plate such that the adhesive layer is in contact with one surface of the metal plate; processing the metal plate by irradiating one surface of the metal plate with a laser while spraying gas onto the laser-processed film and passing the laser-processed film through the metal plate; and peeling the laser-processed film off the processed metal plate, wherein the adhesive layer of the laser-processed film has an adhesive force of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive force of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min.

Description

[Technical Field]

[0001] This invention relates to a laser processing method for metal plates and a method for manufacturing metal plates. [Background technology]

[0002] Conventionally, a method has been used in which a laser-processed metal plate is attached to the metal plate, and a laser is shone onto the metal plate through the laser-processed film to perform laser processing. In this laser processing method, the metal plate is cut while melting it with the laser. The laser-processed film is used to prevent damage during handling, subsequent pressing, and transportation of the processed metal parts.

[0003] Patent Document 1 (Japanese Patent Application Publication No. 2021-187908) discloses a surface protection film comprising a base layer and an adhesive layer provided on at least one surface of the base layer, wherein the base layer comprises a resin and carbon black, and the average particle size of the carbon black is in the range of 20 to 50 nm. Patent Document 2 (Japanese Patent Publication No. 2013-018964) discloses an adhesive film comprising a resin film as a base material and an adhesive layer provided on at least one surface of the resin film, wherein the base material has a laser light absorption rate of 20% or more in the wavelength range of 1000 nm to 1100 nm, and the base material includes a laser light absorption layer made of a resin composition containing carbon black as a laser light absorber to enhance the laser light absorption rate. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-187908 [Patent Document 2] Japanese Patent Publication No. 2013-018964 [Overview of the project] [Problems that the invention aims to solve]

[0005] As described above, in the laser processing method for metal plates using a laser, compressed air, oxygen, nitrogen, or other gases are injected at high pressure into the laser irradiation area of ​​the metal plate to prevent the molten metal from reattaching to the metal plate. During this high-pressure gas injection, the pressure of the gas injection makes it easier to peel the laser-processed film from the metal plate. For this reason, conventional laser-processed films with strong adhesion to the metal plate were used. However, such laser-processed films had the problem of being difficult to peel off the laser-processed film from the metal plate after laser processing. As described above, with conventional laser-processed films, it was difficult to achieve both good adhesion to the metal plate during laser processing (gas injection) and easy peeling from the metal plate after laser processing.

[0006] In view of the limitations of the prior art described above, the present invention aims to provide a laser processing method for a metal plate and a method for manufacturing a metal plate that, with respect to laser-processed films, does not peel off due to gas injection during laser processing and has excellent peelability from the metal plate after laser processing. The inventors of the present invention have discovered that by using an adhesive layer in the evaluation film in which the adhesive force at a specific peeling speed is within a specific range, it is possible to achieve both good adhesion to the metal plate during laser processing (gas injection) and good peelability from the metal plate after laser processing with respect to the laser-processed film, and have completed the present invention. [Means for solving the problem]

[0007] In other words, the present invention and its various embodiments are as follows [1] to [8]. However, the present invention is not limited to the following. [1] A process of laminating a laser-processed film having a light-absorbing substrate and an adhesive layer onto one surface of a metal plate such that the adhesive layer is in contact with one surface of the metal plate, A process of processing a metal plate by irradiating one side of the metal plate through the laser-processed film with a laser while spraying gas onto the laser-processed film, A step of peeling the laser-processed film from the metal plate after processing, A laser processing method for metal plates, comprising: A method for laser processing a metal plate, characterized in that the adhesive layer of the laser-processed film has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. [Measuring Adhesion] (1) 0.90~0.96 g / cm³ 3 An evaluation film is prepared by providing an adhesive layer equivalent to the adhesive layer described above on a polyethylene substrate having a density and a thickness of 90 μm. (2) Prepare a stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm. Degrease the surface of the finished surface of the stainless steel plate with ethanol and dry it to use as the substrate. Under an atmosphere of 23°C and 50% RH, cut the evaluation film to a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact with the surface. After this, using a pressure roller, apply a load of 10 kg from the polyethylene substrate side and press the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Next, using a tensile testing machine, grip one end of the evaluation film, peel the evaluation film from the surface of the stainless steel plate at a peel angle of 180 degrees and a predetermined peel speed, and the strength (N / 25 mm) measured at that time is taken as the adhesive strength. [2] The laser processing method described in [1] above, wherein when the evaluation film is peeled off the stainless steel plate, it has an adhesive force of 3.5 to 7.0 N / 25 mm at a peeling speed of 0.3 m / min. [3] The laser processing method according to [1] or [2] above, wherein when the evaluation film is peeled off the stainless steel plate, the adhesive force is 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min. [4] The aforementioned laser-processed film is A light-absorbing substrate containing carbon black, On the light-absorbing substrate, the adhesive layer and A laser processing method according to [1] or [2] above, comprising: [5] A process of laminating a laser-processed film having a light-absorbing substrate and an adhesive layer onto one surface of a metal plate such that the adhesive layer is in contact with one surface of the metal plate, A process of processing a metal plate by irradiating one side of the metal plate through the laser-processed film with a laser while spraying gas onto the laser-processed film, A step of peeling the laser-processed film from the metal plate after processing, A method for manufacturing a metal plate, having the following characteristics: A method for manufacturing a metal plate, characterized in that the adhesive layer of the laser-processed film has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. [Measuring Adhesion] (1) 0.90~0.96 g / cm³ 3 An evaluation film is prepared by providing an adhesive layer equivalent to the adhesive layer described above on a polyethylene substrate having a density and a thickness of 90 μm. Prepare a stainless steel 304HL finished plate (in accordance with JIS G4305 2021 regulations; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm. Use the surface of the finished surface of the stainless steel plate that has been degreased with ethanol and dried as the adherend. In an atmosphere of 23°C and 50% RH, cut the evaluation film to a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact. After that, using a crimping roller, apply a weight of 10 kg from the polyethylene substrate side and crimp the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Then, using a tensile testing machine, hold one end of the evaluation film and peel the evaluation film from the surface of the stainless steel plate at a peeling angle of 180 degrees and a predetermined peeling speed, and use the strength (N / 25 mm) measured at that time as the adhesive force. [6] The method for manufacturing a metal plate according to [5] above, having an adhesive force of 3.5 to 7.0 N / 25 mm at a peeling speed of 0.3 m / min when peeling the evaluation film from the stainless steel plate. [7] The method for manufacturing a metal plate according to [5] or [6] above, having an adhesive force of 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min when peeling the evaluation film from the stainless steel plate. [8] The laser processing film is a light-absorbing base material containing carbon black, on the light-absorbing base material, the adhesive layer and The method for manufacturing a metal plate according to [5] or [6] above.

Advantages of the Invention

[0008] According to the present invention, regarding the laser processing film, it is possible to provide a laser processing method for a metal plate and a method for manufacturing a metal plate that have no peeling due to gas injection during laser processing and excellent peelability from the metal plate after laser processing.

Brief Description of the Drawings

[0009] [Figure 1] It is a schematic cross-sectional view showing a laser processing film of an embodiment. [Figure 2] It is a schematic diagram showing a laser processing method and a method for manufacturing a metal plate of an embodiment. [Figure 3] It is a schematic plan view of a stainless steel plate on which laser processing was performed in Examples 1 to 4.

Embodiments for Carrying Out the Invention

[0010] <Adhesive layer> The adhesive layer of the present invention has an adhesive force of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive force of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min in the following measurement. [Measurement of Adhesive Force] (1) Prepare an evaluation film provided with an adhesive layer equivalent to the adhesive layer on a polyethylene substrate having a density of 0.90 to 0.96 g / cm 3 and a thickness of 90 μm. (2) Prepare a stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm, and use the surface of the finished surface of the stainless steel plate degreased with ethanol and dried as the adherend. In an atmosphere of 23°C and 50% RH, cut the evaluation film into a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact. After that, using a pressure roller, apply a weight of 10 kg from the polyethylene substrate side, and press the evaluation film onto the stainless steel plate at a speed of 2 m / min and leave it for 24 hours. Then, using a tensile tester, hold one end of the evaluation film, peel the evaluation film from the surface of the stainless steel plate at a peeling angle of 180 degrees and a predetermined peeling speed, and take the strength (N / 25 mm) measured at that time as the adhesive force.

[0011] In the adhesive layer of the present invention, in adhesive strength measurement tests using the evaluation film as described above, the adhesive strength is 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. This prevents peeling due to gas jets during laser processing and allows for excellent peelability from the metal plate after laser processing. In other words, the adhesive layer has a specific dynamic viscoelasticity that exhibits adhesive strength within a specific range at peeling speeds of 0.003 m / min and 0.03 m / min. Therefore, it maintains adhesion to the metal plate against gas jets during laser processing and can adhere effectively to the metal plate. As a result, it is possible to prevent the laser-processed film from peeling off the metal plate due to gas jets during laser processing. Furthermore, when peeling the laser-processed film from the metal plate after laser processing, the adhesive strength of the laser-processed film to the metal plate is low, and the laser-processed film can be given excellent peelability.

[0012] The following describes in detail the measurement test of adhesive strength using the evaluation film in the present invention. (1) First, prepare an evaluation film to be used for measuring adhesive strength. The evaluation film should have an adhesive strength of 0.90-0.96 g / cm². 3 It consists of a polyethylene substrate having a density of 0.90 to 0.96 g / cm³ and a thickness of 90 μm, and an adhesive layer provided on the polyethylene substrate. 3 There are no particular limitations as long as it is a specific (one) density within the range of 0.90~0.96 g / cm³. 3 Within this range, it has been confirmed in advance that the adhesive strength does not change depending on the density of the polyethylene substrate. For example, 0.90~0.96 g / cm³ 3 An evaluation film is prepared by applying an adhesive solution to a substrate of low-density polyethylene (LDPE) film (manufactured by Tamapoly Co., Ltd., product name: M-6, thickness 90 μm) having a specific density within a given range, and then drying the solvent of the adhesive to form an adhesive layer with a thickness of 5 to 12 μm.

[0013] (2) Prepare a stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) measuring 50 mm in width, 200 mm in length, and 0.6 mm in thickness. Degrease the surface of the finished stainless steel plate with ethanol and dry it to use as the substrate. Under an atmosphere of 23°C and 50% RH, cut the evaluation film to a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact with the surface. After this, using a pressure roller, apply a load of 10 kg from the polyethylene substrate side and press the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Next, using a tensile testing machine (ORIENTEC, RTA-1210A), one end of the evaluation film is held, and the evaluation film is peeled from the surface of the stainless steel plate at a peeling angle of 180 degrees and a predetermined peeling speed (0.003 m / min, 0.03 m / min, or 0.3 m / min). The strength measured at that time (N / 25 mm) is defined as the adhesive strength. The adhesive strength measurement test will be described in detail in the examples section.

[0014] In measuring the adhesive strength using the evaluation film, it is preferable to have an adhesive strength of 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min, more preferably 0.7 to 1.6 N / 25 mm, and even more preferably 0.7 to 1.2 N / 25 mm. In measuring the adhesive strength using the evaluation film, it is preferable to have an adhesive strength of 2.0 to 3.5 N / 25 mm at a peeling speed of 0.03 m / min, more preferably 2.0 to 3.0 N / 25 mm, and even more preferably 2.0 to 2.6 N / 25 mm. Furthermore, the evaluation film can have a specific adhesive strength selected from the numerical ranges shown above as the adhesive strength at peeling speeds of 0.003 m / min and 0.03 m / min. This allows the adhesive layer to have suitable dynamic viscoelasticity. As a result, it is possible to prevent the laser-processed film from peeling off the metal plate when gas is injected during laser processing, and the laser-processed film can have excellent peelability when peeling it off the metal plate after laser processing.

[0015] Furthermore, by controlling the type and content ratio of each monomer in the resin constituting the adhesive layer, the degree of crosslinking of the resin, the type and blending ratio of the crosslinking agent, and the film thickness of the adhesive layer, it is possible to achieve an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min in adhesive strength measurement tests using evaluation films. For example, the adhesive strength can be reduced by thinning the film thickness of the adhesive layer, and the adhesive strength can be reduced by increasing the degree of crosslinking of the resin constituting the adhesive layer.

[0016] In the adhesive strength measurement tests of (1) and (2) above using the evaluation film, when peeling the evaluation film from the surface of the stainless steel 304HL finished plate at an even higher peeling speed of 0.3 m / min, it is preferable that the adhesive strength be 3.5 to 7.0 N / 25 mm, more preferably 3.5 to 6.4 N / 25 mm, even more preferably 3.5 to 5.8 N / 25 mm, and particularly preferably 3.5 to 5.2 N / 25 mm.

[0017] The adhesive layer contains components such that, for the evaluation film, it has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. Such components include, for example, a polymer composed of at least one monomer selected from methacrylic acid, acrylic acid, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, acrylonitrile, 2-hydroxyethyl methacrylate, acrylamide, N-methylolacrylamide, divinylbenzene, and polytetramethylene glycol diacrylate. This polymer can be obtained, for example, by emulsion polymerization of the monomers using a solution containing the above monomers, a surfactant, a polymerization initiator, a chain transfer agent, and a solvent. For example, by using a polymer containing predetermined amounts of acrylic acid ester monomer and methacrylic acid ester monomer, an adhesive layer can be created for the evaluation film that has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min.

[0018] The surfactants are not particularly limited, but examples include alkyl sulfate esters, alkylbenzene sulfonates, dialkyl succinate sulfonates, alkyl diphenyl ether disulfonates, polyoxyethylene alkyl ether sulfates, and polyoxyethylene alkylphenyl ether sulfates. More specifically, examples include sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkyl ether sulfate, sodium lauryl sulfate, sodium alkyl diphenyl ether disulfonate, and ammonium=4-nonyl-2-(1-propenyl)phenoxypoly(n=0~29)ethoxyethyl sulfate.

[0019] The polymerization initiator is not particularly limited, but may include t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxyoctanoate, t-butyl peroxyneodecanate, t-butyl peroxyisobutyrate, t-amyl peroxypivalate, t-butyl peroxypivalate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, dicumyl peroxide, dibenzoyl peroxide, dilauroyl peroxide, potassium peroxydisulfate or ammonium peroxydisulfate, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-cyano-2-butane), 2,2'-azobis(methylisobutyrate), 4,4'-azobis(4-cyanopentanoic acid), 4,4'-azobis(4-cyanovaleric acid), 4,4'-azobis(4-cyanopentane-1- Examples include 1,1'-azobis(cyclohexanecarbonitrine), 2,2'-azobis(N,N'-dimethylene isobutylamidine) hydrochloride, 2,2'-azobis(2-amidinopropane) hydrochloride, 2,2'-azobis(N,N'-dimethylene isobutylamine), 2,2'-azobis(2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide), 2,2'-azobis(2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(isobutylamide) hydrate, 2,2'-azobis(2,2,4-trimethylpentane), or 2,2'-azobis(2-methylpropane).

[0020] The chain transfer agent is not particularly limited, but examples include mercaptans such as t-dodecanethiol, lauryl mercaptan, glycidyl mercaptan, 2-mercaptoethanol, mercaptoacetic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol, as well as α-methylstyrene dimer.

[0021] The solvent is not particularly limited, but examples include water, alcohols such as ethanol, methanol, and isopropanol, ketones such as acetone and methyl ethyl ketone, and ethers such as dioxane and tetrahydrofuran.

[0022] <Laser-processed film> The laser-processed film of the present invention comprises a light-absorbing substrate and the above-mentioned adhesive layer on the light-absorbing substrate. The light-absorbing substrate is not particularly limited as long as it can absorb at least a portion of the incident light. The resin constituting the light-absorbing substrate can be one or more selected from polyolefins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamides such as nylon-6, nylon-66, and polymetaxylene adipamide; polyacrylate; polymethacrylate; polyimide; polyetherimide; ethylene-vinyl acetate copolymer; polyacrylonitrile; polycarbonate; polystyrene; ionomer; polysulfone; polyethersulfone; and polyphenylene ether. Among these, one or more selected from polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyimide are preferred from the viewpoint of having an excellent balance of heat resistance, transparency, mechanical strength, and price, and polyethylene is more preferred. Furthermore, the light-absorbing substrate may contain a light-absorbing material, such as carbon black. The light-absorbing substrate is preferably composed of a polyolefin containing carbon black, and more preferably of polyethylene containing carbon black. The light-absorbing substrate may also contain additives such as light stabilizers, ultraviolet absorbers, antioxidants, fillers, lubricants, and dispersants as needed.

[0023] The thickness of the light-absorbing substrate is preferably 20 to 300 μm, more preferably 30 to 200 μm, and even more preferably 40 to 150 μm. The thickness of the adhesive layer is preferably 1 to 50 μm, more preferably 2 to 20 μm, and even more preferably 3 to 10 μm. The overall thickness of the laser-processed film is preferably 20 to 400 μm, more preferably 30 to 350 μm, and even more preferably 40 to 200 μm.

[0024] Figure 1 is a schematic cross-sectional view of a laser-processed film according to one embodiment. The laser-processed film 1 has a light-absorbing substrate 2 and an adhesive layer 3 provided on one surface of the light-absorbing substrate 2. The laser-processed film 1 may consist of the light-absorbing substrate 2 and the adhesive layer 3 as shown in Figure 1, or it may have layers other than the light-absorbing substrate 2 and the adhesive layer 3. The layers other than the light-absorbing substrate 2 and the adhesive layer 3 may include a primer layer disposed between the light-absorbing substrate 2 and the adhesive layer 3. By forming a primer layer, the light-absorbing substrate 2 and the adhesive layer 3 can be bonded well.

[0025] <Method for manufacturing laser-processed film> The method for manufacturing the laser-processed film of the present invention is not particularly limited, as long as an adhesive layer is obtained in which, when an evaluation film is attached to a stainless steel plate and the evaluation film is peeled off from the stainless steel plate, an adhesive layer having an adhesive force of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive force of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min is obtained. For example, an adhesive layer can be obtained by applying a solution containing the components of the adhesive layer to a light-absorbing substrate, and then drying the solution to remove the solvent. In another example, a laser-processed film can be obtained by forming the light-absorbing substrate and the adhesive layer separately, and then attaching the adhesive layer to the light-absorbing substrate. Examples of this method include air-cooled inflation molding, T-die film molding, and water-cooled inflation molding. In yet another example, a laser-processed film can be obtained by forming and laminating the light-absorbing substrate and the adhesive layer in the same process by extrusion. Examples of this method include extrusion lamination, dry lamination, sandwich lamination, and co-extrusion.

[0026] <Method for laser processing metal plates> One aspect of the present invention is, A process of laminating a laser-processed film having a light-absorbing substrate and an adhesive layer onto one surface of a metal plate such that the adhesive layer is in contact with one surface of the metal plate, A process of processing a metal plate by irradiating one side of the metal plate through the laser-processed film with a laser while spraying gas onto the laser-processed film, A step of peeling the laser-processed film from the metal plate after processing, A laser processing method for metal plates, comprising: The laser processing method for a metal plate is characterized in that the adhesive layer of the laser-processed film has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min, as measured below. [Measuring Adhesion] (1) 0.90~0.96 g / cm³3 An evaluation film is prepared by providing an adhesive layer equivalent to the adhesive layer described above on a polyethylene substrate having a density and a thickness of 90 μm. (2) Prepare a stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm. Degrease the surface of the finished surface of the stainless steel plate with ethanol and dry it to use as the substrate. Under an atmosphere of 23°C and 50% RH, cut the evaluation film to a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact with the surface. After this, using a pressure roller, apply a load of 10 kg from the polyethylene substrate side and press the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Next, using a tensile testing machine, grip one end of the evaluation film, peel the evaluation film from the surface of the stainless steel plate at a peel angle of 180 degrees and a predetermined peel speed, and the strength (N / 25 mm) measured at that time is taken as the adhesive strength.

[0027] The laser processing method for metal plates of the present invention allows for laser processing of a workpiece using a laser-processed film. Compared to conventional press processing such as punching thin plates, laser processing allows for the setting and processing of specific, complex shapes, eliminates the need for molds, and can accommodate precision processing and thick plate processing. Figure 2 is a diagram illustrating an example of a laser processing method. As shown in Figure 2A, in the example laser processing method, the laser-processed film 11 of the present invention is attached to one surface of the workpiece 20. Note that in Figure 2, the boundary between the light-absorbing substrate and the adhesive layer in the laser-processed film 11 is not clearly shown. The workpiece 20 is not particularly limited as long as it is a metal plate, but stainless steel plates (stainless steel) are preferred. Stainless steel is not particularly limited and includes austenitic stainless steel (SUS304, SUS316, etc.), ferritic stainless steel (SUS430, etc.), martensitic stainless steel (SUS410, SUS440, etc.), duplex stainless steel (SUS329J1, etc.), and precipitation-hardening stainless steel (SUS630, etc.). For example, a stainless steel 304HL finished plate can be processed as the stainless steel plate. When attaching the laser-processed film 11 to one surface of the workpiece 20, the attachment of the laser-processed film may be accelerated by pressing it with a predetermined load.

[0028] Next, as shown in Figure 2A, the laser 12 is irradiated onto the workpiece 20 from the side where the laser-processed film 11 is attached, while gas 14 is sprayed through the nozzle 15. At this time, the laser 12 is focused through the focusing lens 13, and the focused laser 12 is irradiated onto the workpiece 20 through the laser-processed film 11. As shown in Figure 2B, this laser irradiation melts the workpiece 20, and the workpiece 20 can be cut and processed into the desired shape. In addition, the gas 14 blows away and removes molten material and fragments from the workpiece 20 during laser irradiation, reducing the risk of the workpiece re-solidifying and causing problems such as the formation of slag and dross.

[0029] Here, the adhesive layer constituting the laser-processed film of the present invention has an adhesive force of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min when the evaluation film is peeled from the stainless steel plate, and an adhesive force of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. Therefore, there is no peeling of the laser-processed film due to gas jetting during laser processing.

[0030] Next, the laser-processed film is peeled off the substrate. The peeling speed when peeling off the laser-processed film is not particularly limited, but it is preferably 0.3 to 10 m / min, more preferably 0.3 to 5 m / min, and even more preferably 0.3 to 1 m / min. At this time, when the evaluation film is peeled off the stainless steel plate, the adhesive layer constituting the laser-processed film of the present invention has an adhesive force of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min, an adhesive force of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min, and preferably an adhesive force of 3.5 to 7.0 N / 25 mm at a peeling speed of 0.3 m / min. Therefore, it is possible to have excellent peelability from the substrate after laser processing.

[0031] While there are no particular limitations on the lasers used in laser processing methods, examples include gas lasers such as CO2 lasers and solid-state lasers such as fiber lasers. CO2 lasers generate laser light by exciting a mixture of gases such as carbon dioxide, nitrogen, and helium through electrical discharge. Fiber lasers generate laser light by using an optical fiber as a medium and amplifying light within a glass fiber doped with rare earth elements. While there are no particular limitations on the gases used, examples include compressed air, nitrogen, and oxygen.

[0032] In the laser processing method for metal plates of the present invention, when measuring the adhesive strength using an evaluation film, it is preferable that the adhesive strength is 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min, more preferably 0.7 to 1.6 N / 25 mm, and even more preferably 0.7 to 1.2 N / 25 mm. Furthermore, when measuring the adhesive strength using an evaluation film, it is preferable that the adhesive strength is 2.0 to 3.5 N / 25 mm at a peeling speed of 0.03 m / min, more preferably 2.0 to 3.0 N / 25 mm, and even more preferably 2.0 to 2.6 N / 25 mm. In addition, the evaluation film can have a specific adhesive strength selected from the numerical ranges shown above as the adhesive strength at peeling speeds of 0.003 m / min and 0.03 m / min. This allows the adhesive layer to have suitable dynamic viscoelasticity. As a result, it is possible to prevent the laser-processed film from peeling off the metal plate when gas is injected during laser processing, and the laser-processed film can have excellent peelability when peeling it off the metal plate after laser processing.

[0033] In the laser processing method for metal plates of the present invention, in the adhesive strength measurement tests of (1) and (2) above using an evaluation film, when peeling the evaluation film from the surface of the stainless steel 304HL finished plate at an even higher peeling speed of 0.3 m / min, it is preferable that the adhesive strength is 3.5 to 7.0 N / 25 mm, more preferably 3.5 to 6.4 N / 25 mm, even more preferably 3.5 to 5.8 N / 25 mm, and particularly preferably 3.5 to 5.2 N / 25 mm.

[0034] Furthermore, the laser processing film used in the laser processing method for metal plates of the present invention preferably has a light-absorbing substrate containing carbon black and an adhesive layer on the light-absorbing substrate. By containing carbon black in the light-absorbing substrate, the light-absorbing substrate can effectively absorb the laser, thereby enabling effective processing of the metal plate.

[0035] <Method for manufacturing a metal plate> One aspect of the present invention is a step of laminating a laser processing film having a light-absorbing base material and an adhesive layer on one surface of a metal plate such that the adhesive layer contacts the one surface of the metal plate; a step of irradiating a laser through the laser processing film onto one surface of the metal plate while injecting a gas onto the laser processing film to perform processing of the metal plate; a step of peeling the laser processing film from the processed metal plate; A method for manufacturing a metal plate, comprising: The adhesive layer of the laser processing film has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling rate of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling rate of 0.03 m / min in the following measurement. This is a method for manufacturing a metal plate, which is characterized by this. [Measurement of adhesive strength] (1) Prepare an evaluation film provided with an adhesive layer equivalent to the adhesive layer on a polyethylene base material having a density of 0.90 to 0.96 g / cm 3 and a thickness of 90 μm. (2) Prepare a stainless steel 304HL finished plate (specified by JIS G4305 2021; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm, and use as an adherend the one whose surface of the finished surface of the stainless steel plate is degreased with ethanol and dried. In an atmosphere of 23°C and 50% RH, cut the evaluation film into a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film contacts. After that, using a pressure roller, apply a weight of 10 kg from the polyethylene base material side and press the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Next, using a tensile tester, hold one end of the evaluation film, peel the evaluation film from the surface of the stainless steel plate at a peeling angle of 180 degrees and a predetermined peeling rate, and regard the strength (N / 25 mm) measured at that time as the adhesive strength.

[0036] In the present invention's method for manufacturing a metal sheet, a metal sheet can be manufactured by laser processing a workpiece using a laser-processed film. Compared to conventional press processing such as punching thin sheets, laser processing allows for the setting and processing of specific, complex shapes, eliminates the need for molds, and can accommodate precision processing and thick plate processing. Figure 2 shows an example of a method for manufacturing a metal sheet. As shown in Figure 2A, in the example of a method for manufacturing a metal sheet, the laser-processed film 11 of the present invention is attached to one surface of the workpiece 20. Note that in Figure 2, the boundary between the light-absorbing substrate and the adhesive layer in the laser-processed film 11 is not clearly shown. When attaching the laser-processed film 11 to one surface of the workpiece 20, the attachment of the laser-processed film may be accelerated by pressing it with a predetermined load.

[0037] Next, as shown in Figure 2A, the laser 12 is irradiated onto the workpiece 20 from the side where the laser-processed film 11 is attached, while gas 14 is sprayed through the nozzle 15. At this time, the laser 12 is focused through the focusing lens 13, and the focused laser 12 is irradiated onto the workpiece 20 through the laser-processed film 11. As shown in Figure 2B, the workpiece 20 is melted by the laser irradiation, and the workpiece 20 can be cut into the desired shape to manufacture a metal plate. In addition, the gas 14 blows away and removes molten material and fragments from the workpiece 20 during laser irradiation, reducing the risk of the workpiece re-solidifying and causing problems such as the formation of slag and dross.

[0038] In the present invention's method for manufacturing a metal plate, when measuring the adhesive strength using an evaluation film, it is preferable that the adhesive strength is 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min, more preferably 0.7 to 1.6 N / 25 mm, and even more preferably 0.7 to 1.2 N / 25 mm. Furthermore, when measuring the adhesive strength using an evaluation film, it is preferable that the adhesive strength is 2.0 to 3.5 N / 25 mm at a peeling speed of 0.03 m / min, more preferably 2.0 to 3.0 N / 25 mm, and even more preferably 2.0 to 2.6 N / 25 mm. In addition, the evaluation film can have a specific adhesive strength selected from the numerical ranges shown above as the adhesive strength at peeling speeds of 0.003 m / min and 0.03 m / min. This allows the adhesive layer to have suitable dynamic viscoelasticity. As a result, it is possible to prevent the laser-processed film from peeling off the metal plate when gas is injected during laser processing, and the laser-processed film can have excellent peelability when peeling it off the metal plate after laser processing.

[0039] In the metal plate manufacturing method of the present invention, in the adhesive strength measurement tests of (1) and (2) above using an evaluation film, when peeling the evaluation film from the surface of the stainless steel 304HL finished plate at an even higher peeling speed of 0.3 m / min, it is preferable that the adhesive strength is 3.5 to 7.0 N / 25 mm, more preferably 3.5 to 6.4 N / 25 mm, even more preferably 3.5 to 5.8 N / 25 mm, and particularly preferably 3.5 to 5.2 N / 25 mm.

[0040] Furthermore, the laser-processed film used in the metal plate manufacturing method of the present invention preferably has a light-absorbing substrate containing carbon black and an adhesive layer on the light-absorbing substrate. By containing carbon black in the light-absorbing substrate, the light-absorbing substrate can effectively absorb the laser, enabling the effective manufacturing of the metal plate. [Examples]

[0041] The present invention will be described in detail below with reference to examples and comparative examples. However, the present invention is not limited in any way to the following examples.

[0042] The adhesive resins 1 to 8 for the adhesive layer were prepared as follows. (Adhesive resin 1) In a polymerization reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet, 51.51 parts by mass of deionized water, 0.19 parts by mass of potassium persulfate as a polymerization initiator, 42.17 parts by mass of 2-ethylhexyl acrylate as monomers, 4.83 parts by mass of acrylonitrile, 0.77 parts by mass of acrylic acid, 0.36 parts by mass of N-methylolacrylamide, 0.02 parts by mass of t-dodecyl mercaptan as a molecular weight modifier, and 0.15 parts by mass of sodium alkyldiphenyl ether disulfonate as a surfactant were added, and emulsion polymerization was carried out at 70°C for 8 hours with stirring under a nitrogen atmosphere. The resulting emulsion was neutralized with aqueous ammonia solution (pH=7.0). By the above procedure, an adhesive resin solution 1 containing 47.3 parts by mass of adhesive resin was obtained. Next, to obtain the adhesive resin 1, a crosslinking agent and an organic solvent were added in a ratio of 0.15 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) and 0.15 parts by mass of diethylene glycol monobutyl ether as an organic solvent, respectively, per 100 parts by mass of the adhesive resin solution 1.

[0043] (Adhesive resin 2) To 100 parts by mass of the same adhesive resin solution 1 used to prepare the adhesive resin 1 described above, 0.2 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) and 0.2 parts by mass of diethylene glycol monobutyl ether were added as a crosslinking agent and organic solvent to obtain adhesive resin 2.

[0044] (Adhesive resin 3) In a polymerization reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet, 54.31 parts by mass of deionized water, 0.23 parts by mass of potassium persulfate as a polymerization initiator, 18.89 parts by mass of 2-ethylhexyl acrylate, 18.89 parts by mass of butyl acrylate, 3.60 parts by mass of acrylonitrile, 2.25 parts by mass of methacrylic acid, 1.35 parts by mass of acrylamide, 0.23 parts by mass of 57% divinylbenzene as monomers, and 0.25 parts by mass of sodium alkyldiphenyl ether disulfonate as a surfactant were added, and emulsion polymerization was carried out at 70°C for 8 hours with stirring under a nitrogen atmosphere. The resulting emulsion was neutralized with aqueous ammonia solution (pH=7.0). By the above procedure, an adhesive resin solution 3 containing 44.4 parts by mass of adhesive resin was obtained. To obtain the adhesive resin 3, a crosslinking agent and an organic solvent were added in such proportions as 0.15 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) and 0.15 parts by mass of diethylene glycol monobutyl ether as an organic solvent, respectively, per 100 parts by mass of the above adhesive resin solution 3.

[0045] (Adhesive resin 4) To 100 parts by mass of the same adhesive resin solution 3 used to prepare the above-mentioned adhesive resin 3, 0.2 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) and 0.2 parts by mass of diethylene glycol monobutyl ether were added as a crosslinking agent and organic solvent to obtain adhesive resin 4.

[0046] (Adhesive resin 5) To 100 parts by mass of the same adhesive resin solution 3 used to prepare the above-mentioned adhesive resin 3, 0.4 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) was added as a crosslinking agent, and 0.4 parts by mass of diethylene glycol monobutyl ether was added as an organic solvent to obtain the adhesive resin 5.

[0047] (Adhesive resin 6) In a polymerization reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet, 57.01 parts by mass of deionized water, 0.27 parts by mass of 4-cyanovaleric acid as a polymerization initiator, 31.50 parts by mass of butyl acrylate, 5.81 parts by mass of methyl methacrylate, 3.82 parts by mass of 2-hydroxyethyl methacrylate, 0.85 parts by mass of methacrylic acid, 0.42 parts by mass of acrylamide as monomers, and 0.32 parts by mass of ammonium=4-nonyl-2-(1-propenyl)phenoxypoly(n=0~29)ethoxyethyl sulfate (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-10) as a surfactant were added, and emulsion polymerization was carried out at 70°C for 8 hours with stirring under a nitrogen atmosphere. The resulting emulsion was neutralized with aqueous ammonia solution (pH=7.0). By the above procedure, an adhesive resin solution 6 containing 42.8 parts by mass of adhesive resin was obtained. To obtain the adhesive resin 6, a crosslinking agent and an organic solvent were added in such proportions that 0.15 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) and 0.15 parts by mass of diethylene glycol monobutyl ether were added to 100 parts by mass of the above adhesive resin solution 6.

[0048] (Adhesive resin 7) In a polymerization reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet, 57.79 parts by mass of deionized water, 0.26 parts by mass of 4-cyanovaleric acid as a polymerization initiator, 26.23 parts by mass of 2-ethylhexyl acrylate, 7.49 parts by mass of butyl acrylate, 5.00 parts by mass of methyl methacrylate, 1.25 parts by mass of 2-hydroxyethyl methacrylate, 0.83 parts by mass of methacrylic acid, 0.42 parts by mass of acrylamide, 0.42 parts by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, product name: Bremmer ADT-250), and 0.31 parts by mass of ammonium=4-nonyl-2-(1-propenyl)phenoxypoly(n=0~29)ethoxyethyl sulfate (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-10) as a surfactant were added, and emulsion polymerization was carried out at 70°C for 8 hours with stirring under a nitrogen atmosphere. The resulting emulsion was neutralized with an aqueous ammonia solution (pH=7.0). By the above procedure, an adhesive resin solution 7 containing 42.0 parts by mass of adhesive resin was obtained. To 100 parts by mass of the above adhesive resin solution 7, 0.15 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) was added as a crosslinking agent, and 0.15 parts by mass of diethylene glycol monobutyl ether was added as an organic solvent to obtain an adhesive resin 7.

[0049] (Adhesive resin 8) In a polymerization reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet, 43.62 parts by mass of deionized water, 0.28 parts by mass of potassium peroxydisulfate as a polymerization initiator, 35.17 parts by mass of 2-ethylhexyl acrylate, 11.72 parts by mass of butyl acrylate, 5.02 parts by mass of methyl methacrylate, 1.67 parts by mass of 2-hydroxyethyl methacrylate, 1.12 parts by mass of methacrylic acid as monomers, 0.56 parts by mass of acrylamide, 0.56 parts by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, product name: Bremmer ADT-250), and 0.28 parts by mass of ammonium=4-nonyl-2-(1-propenyl)phenoxypoly(n=0~29)ethoxyethyl sulfate (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-10) as a surfactant were added, and emulsion polymerization was carried out at 70°C for 8 hours with stirring under a nitrogen atmosphere. The resulting emulsion was neutralized with an aqueous ammonia solution (pH=7.0). By the above procedure, an adhesive resin solution 8 containing 56.1 parts by mass of adhesive resin was obtained. To 100 parts by mass of the above adhesive resin solution 8, a crosslinking agent and an organic solvent were added in the following proportions: 0.15 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name: Denacol EX-614) as the crosslinking agent and 0.15 parts by mass of diethylene glycol monobutyl ether as the organic solvent to obtain an adhesive resin 8.

[0050] [Reference example 1] An aqueous ammonia solution was added to adhesive resin 1 to adjust the pH to 9, and the viscosity was adjusted to 100 mPa·s using pure water to obtain adhesive solution 1.

[0051] [Reference examples 2~8] Adhesive solutions 2 to 8 were prepared in the same manner as in Reference Example 1, except that adhesive resins 2 to 8 were used instead of adhesive solution 1, as shown in Table 1 below. The pH of each adhesive solution 2 to 8 was adjusted to 7.5 to 9.5 by adding an aqueous ammonia solution, and the viscosity was adjusted to 20 to 200 mPa·s using pure water.

[0052] Using the adhesive solutions 1 to 8 obtained as described above, the following were evaluated: (a) adhesive strength when the evaluation film was peeled off at peeling speeds of 0.003 m / min, 0.03 m / min, and 0.3 m / min; (b) laser processability; and (c) adhesive residue. The measurement methods for the above characteristics (a) to (c) are described below.

[0053] (a) Measurement of adhesive strength when the evaluation film is peeled off at peeling speeds of 0.003 m / min, 0.03 m / min, and 0.3 m / min. <Method for preparing evaluation films> 0.90~0.96 g / cm³ 3 Low-density polyethylene (LDPE) film having a specific density within the range (manufactured by Tamapoly Co., Ltd., product name: M-6, thickness 90 μm, 0.93 g / cm²) 3 One of the adhesive solutions 1 to 8 obtained in Reference Examples 1 to 8 was applied to the substrate. After that, the solution was dried to form an adhesive layer with a thickness of 5 to 12 μm, thereby preparing an evaluation film. The evaluation films obtained using the adhesive solutions 1 to 4 obtained in Reference Examples 1 to 4 were designated as Examples 1 to 4, and the evaluation films obtained using the adhesive solutions 5 to 8 obtained in Reference Examples 5 to 8 were designated as Comparative Examples 1 to 4. The adhesive strength of the evaluation films thus prepared was measured according to the following procedure. The obtained adhesive strength results are shown in Table 1.

[0054] <Measuring Adhesion> A stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) measuring 50 mm in width, 200 mm in length, and 0.6 mm in thickness was prepared. The surface of the finished stainless steel plate was then degreased with ethanol and dried to serve as the substrate. Under an atmosphere of 23°C and 50% RH, the evaluation films obtained in Examples 1-4 and Comparative Examples 1-4 were cut to a length of 100 mm and a width of 25 mm, and temporarily attached to the surface of the finished stainless steel plate using a hand roller so that the adhesive layer of the film was in contact with the surface. After this, a pressure roller was used to apply a load of 10 kg from the polyethylene base film side at a speed of 2 m / min to press the evaluation film onto the stainless steel plate, and it was left for 24 hours. Next, using a tensile testing machine (ORIENTEC RTA-1210A), one end of the evaluation film was held, and the evaluation film was peeled from the surface of the stainless steel 304HL finished plate at a peeling angle of 180 degrees and peeling speeds of 0.003 m / min, 0.03 m / min, or 0.3 m / min. The strength (N / 25mm) measured at that time was defined as the adhesive strength.

[0055] (b) Laser processability <Method for preparing films for practical evaluation> One of the adhesive solutions 1 to 8 obtained in Reference Examples 1 to 8 was applied to a substrate of low-density polyethylene (LDPE, 90 μm thick) containing carbon black. Afterward, the solution was dried to form an adhesive layer with a thickness of 5 to 12 μm, thereby producing a film for practical evaluation. The practical evaluation films obtained using adhesive solutions 1 to 4 from Reference Examples 1 to 4 were designated as Examples 1 to 4, while the practical evaluation films obtained using adhesive solutions 5 to 8 from Reference Examples 5 to 8 were designated as Comparative Examples 1 to 4. The following evaluations were performed on the prepared practical evaluation films. The results are shown in Table 1 below.

[0056] <Evaluation of laser processability> The surface of a 300mm wide, 300mm long, and 2mm thick stainless steel 304HL finished plate (as specified in JIS G4305 2021; stainless steel plate) was degreased with ethanol and air-dried. After this, the practical evaluation films obtained in Examples 1-4 and Comparative Examples 1-4 were bonded to one surface of the stainless steel 304HL finished plate via their adhesive layers using a roller. In Examples 1-4 and Comparative Examples 1-4, the stainless steel 304HL finished plate 10 to which the practical evaluation film was bonded was laser-processed to obtain a workpiece of a predetermined shape as shown in Figure 3. More specifically, in Examples 1-4 and Comparative Examples 1, 2, and 4, a Mitsubishi Electric ML3015 GX-F100 fiber laser processing machine was used, operating under the conditions of output 4.0kW, speed 21m / min, gas: nitrogen (gas injection pressure: 0.9MPa), nozzle focus -1.5mm, and nozzle height 1.5mm relative to the test film. Laser processing was performed by irradiating a stainless steel 304HL finished plate 10, to which the practical evaluation film had been laminated, from the practical evaluation film side. In contrast, in Comparative Example 3, a Mitsubishi Electric ML3015HV2-R-45CF-R CO2 laser processing machine was used, operating under the conditions of output 4.0kW, speed 4m / min, gas: nitrogen (gas injection pressure: 0.9MPa), and nozzle focus -1.5mm. Laser processing was performed by irradiating a stainless steel 304HL finished plate 10, to which the practical evaluation film had been laminated, from the practical evaluation film side. In this process, laser processing was possible without the evaluation film peeling off, and was marked with a "○" if the evaluation film peeled off. The results are shown in Table 1 below.

[0057] (c) Adhesive residue Similarly to (b) above, the adhesive residue was visually inspected when the practical evaluation film was peeled off by hand from the laser-processed stainless steel 304 No.2B finish (JIS G4305 2021 standard; stainless steel sheet) and stainless steel 2B finish sheet (stainless steel sheet). Then, sheets with no adhesive residue on the stainless steel 304 No.2B finish sheet and stainless steel 2B finish sheet were evaluated as "○", and sheets with adhesive residue were evaluated as "×". The results obtained are shown in Table 1 below.

[0058] [Table 1]

[0059] As shown in Table 1 above, Examples 1 to 4 have an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min, 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min, and 3.5 to 7.0 N / 25 mm at a peeling speed of 0.3 m / min. Therefore, in practical evaluations, Examples 1 to 4 were evaluated as "○" for laser processability and adhesive residue, there was no peeling due to gas injection during laser processing, and it was confirmed that they have excellent peelability from the metal plate after laser processing. On the other hand, Comparative Examples 1 to 4 have an adhesive strength of less than 0.7 N / 25 mm or more than 2.5 N / 25 mm at a peeling speed of 0.003 m / min, and an adhesive strength of less than 2.0 N / 25 mm or more than 4.0 N / 25 mm at a peeling speed of 0.03 m / min. Therefore, in Comparative Examples 1 to 4, the practical evaluation showed that laser processability or adhesive residue was "X," confirming that it was not possible to achieve both prevention of peeling due to gas injection during laser processing and excellent peelability from the metal plate after laser processing. [Explanation of Symbols]

[0060] 1. Laser-cut film 2. Light-absorbing substrate 3. Adhesive layer 10 stainless steel plates 11 Laser-cut film 12 lasers 13. Focusing lens 14 Gas 15 nozzles 20 Clothing

Claims

1. A process of laminating a laser-processed film having a light-absorbing substrate and an adhesive layer onto one surface of a metal plate such that the adhesive layer is in contact with one surface of the metal plate, A process of processing a metal plate by irradiating one side of the metal plate through the laser-processed film with a laser while spraying gas onto the laser-processed film, A step of peeling the laser-processed film from the metal plate after processing, A laser processing method for metal plates, comprising: A method for laser processing a metal plate, characterized in that the adhesive layer of the laser-processed film has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. [Measurement of adhesive strength] (1) 0.90-0.96g / cm ３ An evaluation film is prepared by providing an adhesive layer equivalent to the adhesive layer described above on a polyethylene substrate having a density and a thickness of 90 μm. (2) Prepare a stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm. Degrease the surface of the finished surface of the stainless steel plate with ethanol and dry it to use as the substrate. In an atmosphere of 23°C and 50% RH, cut the evaluation film to a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact with it. After this, using a pressure roller, apply a load of 10 kg from the polyethylene substrate side and press the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Next, using a tensile testing machine, grip one end of the evaluation film and peel the evaluation film from the surface of the stainless steel plate at a peeling angle of 180 degrees and a predetermined peeling speed, and the strength (N / 25 mm) measured at that time is taken as the adhesive strength.

2. The laser processing method according to claim 1, wherein when the evaluation film is peeled off the stainless steel plate, it has an adhesive force of 3.5 to 7.0 N / 25 mm at a peeling speed of 0.3 m / min.

3. The laser processing method according to claim 1 or 2, wherein when the evaluation film is peeled off the stainless steel plate, it has an adhesive strength of 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min.

4. The aforementioned laser-processed film is A light-absorbing substrate containing carbon black, On the light-absorbing substrate, the adhesive layer and A laser processing method according to claim 1 or 2, comprising:

5. A process of laminating a laser-processed film having a light-absorbing substrate and an adhesive layer onto one surface of a metal plate such that the adhesive layer is in contact with one surface of the metal plate, A process of processing a metal plate by irradiating one side of the metal plate through the laser-processed film with a laser while spraying gas onto the laser-processed film, A step of peeling the laser-processed film from the metal plate after processing, A method for manufacturing a metal plate, having the following characteristics: A method for manufacturing a metal plate, characterized in that the adhesive layer of the laser-processed film has an adhesive strength of 0.7 to 2.5 N / 25 mm at a peeling speed of 0.003 m / min and an adhesive strength of 2.0 to 4.0 N / 25 mm at a peeling speed of 0.03 m / min. [Measurement of adhesive strength] (1) 0.90-0.96g / cm ３ An evaluation film is prepared by providing an adhesive layer equivalent to the adhesive layer described above on a polyethylene substrate having a density and a thickness of 90 μm. (2) Prepare a stainless steel 304HL finished plate (JIS G4305 2021 standard; stainless steel plate) with a width of 50 mm, a length of 200 mm, and a thickness of 0.6 mm. Degrease the surface of the finished surface of the stainless steel plate with ethanol and dry it to use as the substrate. In an atmosphere of 23°C and 50% RH, cut the evaluation film to a length of 100 mm and a width of 25 mm, and temporarily attach it to the surface of the finished surface of the stainless steel plate using a hand roller so that the adhesive layer of the evaluation film is in contact with it. After this, using a pressure roller, apply a load of 10 kg from the polyethylene substrate side and press the evaluation film onto the stainless steel plate at a speed of 2 m / min, and leave it for 24 hours. Next, using a tensile testing machine, grip one end of the evaluation film and peel the evaluation film from the surface of the stainless steel plate at a peeling angle of 180 degrees and a predetermined peeling speed, and the strength (N / 25 mm) measured at that time is taken as the adhesive strength.

6. The method for manufacturing a metal plate according to claim 5, wherein when the evaluation film is peeled off the stainless steel plate, the adhesive force is 3.5 to 7.0 N / 25 mm at a peeling speed of 0.3 m / min.

7. A method for manufacturing a metal plate according to claim 5 or 6, wherein when the evaluation film is peeled off the stainless steel plate, the adhesive force is 0.7 to 2.0 N / 25 mm at a peeling speed of 0.003 m / min.

8. The aforementioned laser-processed film is A light-absorbing substrate containing carbon black, On the light-absorbing substrate, the adhesive layer and A method for manufacturing a metal plate according to claim 5 or 6, comprising having

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