JP5221012B2 - Surface protection sheet for laser processing - Google Patents

Description

  The present invention relates to a laser processing surface protection sheet that is affixed to a workpiece that is cut by irradiation with a laser beam.

  Made of resin material to protect the surface of metal plates, painted metal plates, aluminum sashes, resin plates, decorative copper plates, vinyl chloride laminated steel plates, glass plates, etc. when transporting, processing or curing them The pasting of the sheet is conventionally performed.

  The characteristics required for the surface protective sheet include that the protective sheet does not float or peel after being attached to the adherend, and that the adhesive layer does not remain on the adherend when it is peeled and removed. Furthermore, it is required that when the adherend is processed with the surface protective sheet applied, the surface protective sheet is not lifted or peeled off, and the adherend is free from scratches or adhesive residue. For example, Patent Documents 1 and 2 disclose surface protective sheets for metal plates.

  Among the processing methods for plate-like members, laser cutting has excellent advantages. As an advantage, unlike punching, it can be implemented simply by inputting design data without requiring various dies, and the workpiece (hereinafter also referred to as a workpiece) is a metal plate in particular. Can be carried out in a shorter period of time than punching, can be carried out even if the workpiece is thick, and can be carried out without using lubricating oil. For this reason, the laser cutting market is on an expanding trend. However, the laser cutting process requires the supply of assist gas at a high pressure (about 0.5 to 1.5 MPa).

By the way, for reasons of appearance and the like, it may be desirable to subject the workpiece to laser cutting while the surface protection sheet is still attached. In such a case, there has been a problem that the surface protection sheet is undesirably peeled off from the work due to the influence of the assist gas. As means for solving these problems, Patent Documents 3 to 5 propose laser cutting methods that can suppress peeling during laser cutting. In these processing methods, it is possible to suppress peeling of the protective sheet.
JP 2000-328022 A JP 2002-302657 A JP-A-2-295688 JP-A-7-241688 JP 2001-212690 A

  However, in any of the methods disclosed in Patent Documents 3 to 5, peeling of the surface protective sheet on the surface of the workpiece that is irradiated with the laser beam is a problem. The reason is considered that the effect of the assist gas appears only on the surface irradiated with the laser beam. On the other hand, a surface protective sheet is not actually applied to the surface of the workpiece opposite to the surface irradiated with the laser beam. When the present inventors actually performed laser cutting with the surface protective sheet of the above-mentioned prior art attached to the surface opposite to the surface irradiated with the laser beam, laser cutting without attaching the surface protective sheet was performed. It has been found that new problems arise that have not been found at all when processing. That is, burrs (dross) were generated in the vicinity of the cut portion. FIG. 2 is an explanatory diagram of such dross. FIG. 4A is a perspective view, in which a cylindrical through hole 300 is formed by laser cutting. In the laser cutting processing that the present inventors tried, the laser beam was applied to the surface 200a opposite to the surface to which the surface protection sheet 100 of the workpiece 200 was attached. FIG. 4B is a cross-sectional view taken along the line II of FIG. 2A, and a dross 210 having a height t is generated on the surface opposite to the surface 200a irradiated with the laser beam. When the dross 210 is generated in this way, an additional step of removing the dross is necessary, which is not preferable. Further, when the workpiece 200 is laser cut, the surface in contact with the surface protective sheet 100 is a sharp base in most cases, and when the surface protective sheet 100 is not present, This work itself may be damaged.

  An object of the present invention is to protect the surface of an adherend, which is the original role of a protective sheet, and to stick to a surface opposite to a laser beam irradiation surface, which is unlikely to cause dross during laser cutting. It aims at providing the surface protection sheet for laser processing.

The present inventors have made it difficult for the melt of the workpiece during laser cutting to be blown off with the assist gas by the surface protective sheet affixed to the surface opposite to the laser beam irradiation surface, and as a result, dross is likely to occur. And found a surface protection sheet for laser processing that hardly causes such a problem. The features of the present invention are as follows.
(1) A surface protection sheet for laser processing for applying a laser beam to a surface opposite to the laser beam irradiation surface of the workpiece when irradiating the workpiece with a laser beam, the substrate layer and one surface thereof The base material layer is made of a resin material having a melt viscosity of 200 Pa · s or less measured at 290 ° C. based on JIS K7199 (1999), and the thickness of the base material layer is The surface protection sheet for laser processing which is 0.01-0.12 mm.
(2) The surface protection sheet for laser processing according to (1), wherein the resin material is a polyester resin.
(3) The surface protective sheet for laser processing according to (2), wherein the polyester resin is a polyethylene terephthalate resin.
(4) The surface protective sheet for laser processing according to (1), wherein the resin material is a polyolefin resin.
(5) The surface protection sheet for laser processing according to any one of (1) to (4), wherein the workpiece is a metal plate.
(6) The surface protective sheet for laser processing according to (5), wherein the metal plate is a stainless steel plate.
(7) The surface protective sheet for laser processing according to (5), wherein the metal plate is an aluminum plate.

  In the surface protection sheet for laser processing of the present invention, dross is less likely to occur during laser cutting processing. Therefore, it becomes possible to use it for laser cutting processing in the state protected especially so that the surface on the opposite side to the laser irradiation surface of a workpiece | work, such as a metal plate, may be hard to be damaged. In one embodiment of the present invention, by providing a surface protection sheet that is less peeled by the assist gas on the surface irradiated with the laser beam (200a side in FIG. 2 (B)), a workpiece that has been impossible in the past has been impossible. Laser cutting can be performed in a state in which sheets are pasted on both sides.

  The surface protection sheet for laser processing of the present invention includes a base material layer and an adhesive layer. The base material layer is made of a resin material exhibiting a specific melt viscosity and has a thickness within a specific range. The pressure-sensitive adhesive layer is formed on one side of the base material layer.

The melt viscosity of the resin material constituting the base material layer is measured based on JIS K7199 (1999). More specifically, a measurement sample is sampled as follows, and a melt viscosity is obtained through measurement of a test pressure and a volume flow rate at 290 ° C. using a capillary die. A specific method for sampling the measurement sample is as follows.
-When the resin material which comprises a base material layer is clear, the resin material is pelletized and a measurement sample is obtained.
-When an adhesive layer and a base material layer are separable, an adhesive layer is removed using an organic solvent etc., only a base material layer is cut finely and a measurement sample is obtained.
-When it is difficult to separate the pressure-sensitive adhesive layer and the base material layer, a sample obtained by finely cutting the entire surface protective sheet is used as a measurement sample, and the melt viscosity obtained by measuring the measurement sample is used as a basis. It is determined that it is the melt viscosity of the resin material constituting the material layer.
-When a base material layer is a multilayer structure, the whole base material layer is cut finely and a measurement sample is obtained.

  In the present invention, a resin material having a melt viscosity measured as described above of 200 Pa · s or less, preferably 150 Pa · s or less, more preferably 20 to 100 Pa · s is used as the material of the base material layer. If the melt viscosity exceeds 200 Pa · s, dross is likely to occur as a result of the difficulty in blowing the base material layer at the laser cutting site. If the melt viscosity is within the above preferred range, the dross blown by the assist gas becomes easier and the film can be formed more easily.

  The resin material having a melt viscosity of 200 Pa · s or less measured at 290 ° C. is typically made of a polyester resin, among which polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polylactic acid. And polycarbonate. Other amide polymers such as 6-nylon, 6,6-nylon and 12-nylon, styrene polymers such as HIPS and GPPS; acrylic polymers such as polymethyl methacrylate; propylene polymers, ethylene polymers and ethylene Examples thereof include polyolefin resins such as copolymer polymers. Examples of the propylene polymer include single polymers, block polymers, and random polymers. Examples of the ethylene-based polymer include low density, high density, and linear low density. Examples of the ethylene copolymer include a copolymer of ethylene and a polar polymer such as vinyl acetate, methyl methacrylate, and acrylic acid. These polymers may be used alone or in combination as a resin material. The melt viscosity of the above-listed resins is not necessarily within the above range, and resins that can be used in the present invention can be easily found by measuring these resins according to JIS. Further, the base material layer may have a multilayer structure or the like.

  As long as the effect of the present invention is not impaired, the base material layer includes fillers such as calcium carbonate, talc and calcium oxide, anti-blocking agents, lubricants, titanium oxide, organic and inorganic pigments for coloring purposes, and prevention of deterioration. Suitable additives such as antioxidants, ultraviolet absorbers, light stabilizers and antistatic agents for the purpose of the above can also be blended. Furthermore, a plasticizer etc. can be mix | blended in order to improve the softness | flexibility of a base material layer. Further, surface treatment such as corona treatment may be applied to the substrate surface for the purpose of improving the adhesion with the back surface treatment agent, the pressure sensitive adhesive and the undercoat. From the viewpoint of preventing dross and ensuring the action as a protective sheet, the lower limit of the thickness of the base material layer is 0.01 mm, preferably 0.02 mm. The upper limit of the thickness of the base material layer is 0.12 mm, preferably 0.10 mm, and more preferably 0.05 mm.

Next, the pressure-sensitive adhesive layer will be described.
The pressure-sensitive adhesive layer is provided on one side of the base material layer. The pressure-sensitive adhesive layer only needs to have adhesion to a stainless steel plate which is a typical workpiece. As the pressure-sensitive adhesive as a material for the pressure-sensitive adhesive layer, known rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, and polyurethane-based pressure-sensitive adhesives can be used. Among these, rubber adhesives and acrylic adhesives are preferable from the viewpoints of adhesion to metal plates, releasability, and cost. The pressure-sensitive adhesive layer using these pressure-sensitive adhesives is preferable because it also has adhesion to a metal plate or glass plate other than the stainless steel plate.

Examples of the rubber-based pressure-sensitive adhesive include natural rubber-based pressure-sensitive adhesives and synthetic rubber-based pressure-sensitive adhesives. Synthetic rubber adhesives include polybutadiene, polyisoprene, butyl rubber, polyisobutylene, styrene elastomers such as styrene / butadiene / styrene block copolymers, styrene / ethylene butylene / styrene block copolymers, and styrene / ethylene butylene / random copolymers. Styrene elastomers such as polymers, ethylene propylene rubber, propylene butene rubber, ethylene propylene butene rubber and the like are used as the main components.
Examples of the acrylic pressure-sensitive adhesive include 2-hydroxyethyl as a modifying monomer which is mainly composed of alkyl (meth) acrylate such as butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, and can be copolymerized therewith if necessary. Copolymerization of monomer mixture with other monomers such as hydroxyl group-containing monomers such as (meth) acrylate, carboxyl group-containing monomers such as (meth) acrylic acid, styrene monomers such as styrene, vinyl esters such as vinyl acetate Coalescence is used. The acrylic pressure-sensitive adhesive can be obtained by a conventional polymerization method such as a solution polymerization method, an emulsion polymerization method, or a UV polymerization method.

  If necessary, for the purpose of controlling the adhesive properties of these adhesives, for example, crosslinking agents, tackifiers, softeners, olefin resins, silicone polymers, liquid acrylic copolymers, phosphate ester compounds, Light stabilizers such as anti-aging agents, hindered amine light stabilizers, ultraviolet absorbers, and other suitable additives such as fillers and pigments such as calcium oxide, magnesium oxide, calcium carbonate, silica, zinc oxide, and titanium oxide. Can be blended.

The compounding of the tackifier is effective for improving the adhesive force, and the blending amount is about 100 parts by weight of the above-mentioned pressure-sensitive adhesive from the viewpoint of improving the adhesive force while avoiding the occurrence of the adhesive residue problem due to the decrease in cohesive force. 0 to 50 parts by weight, especially 0 to 30 parts by weight, especially 0 to 10 parts by weight are preferred. Here, 0 part by weight means that no tackifier is blended.
Examples of tackifiers include aliphatic resins, aromatic resins, aliphatic / aromatic copolymer systems and alicyclic petroleum resins, coumarone indene resins, terpene resins, terpene phenol resins and polymerization. One type or two or more types of known pressure-sensitive adhesives such as rosin resins, (alkyl) phenol resins, xylene resins, or hydrogenated resins thereof can be used.

  The blending of the softener is usually effective for improving the adhesive strength. As the softening agent, for example, one kind or two or more kinds of low molecular weight diene polymer, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene and derivatives thereof can be used, and the blending amount thereof may be appropriately set. Especially, 0 to 40 parts by weight, especially 0 to 20 parts by weight, especially 0 to 10 parts by weight are preferable per 100 parts by weight of the pressure-sensitive adhesive described above. Here, 0 part by weight means that no softener is blended. When the blending amount is 40 parts by weight or less, there is little adhesive residue even at high temperatures or outdoor exposure.

  The thickness of the pressure-sensitive adhesive layer can be appropriately set according to the adhesive force and the like, and is generally 0.001 to 0.050 mm, in particular 0.002 to 0.020 mm, and particularly 0.003 to 0.015 mm. If necessary, the pressure-sensitive adhesive layer can be temporarily attached with a separator or the like until it is put to practical use.

  The surface protective sheet for laser processing is formed by, for example, applying a solution obtained by dissolving the pressure-sensitive adhesive composition in a solvent or a hot melt to the base material layer, forming the pressure-sensitive adhesive layer on the separator, and then forming the base material layer. Transfer method, material for forming the pressure-sensitive adhesive layer is extrusion-coated on the base material layer, method of co-extrusion of the base material layer and the pressure-sensitive adhesive layer in two or multiple layers, on the base material layer A method for laminating a pressure-sensitive adhesive layer on a single layer, a method for laminating a pressure-sensitive adhesive layer together with a laminate layer on a base material layer, a method for laminating a pressure-sensitive adhesive layer and a base material layer, a laminate layer, etc. It can carry out according to the formation method of this well-known adhesive sheet.

  The surface protection sheet for laser processing of the present invention may include a release layer. As the back surface treatment agent for forming the release layer, those made of a solvent-based or solvent-free silicone polymer or a long-chain alkyl polymer are generally used. Specifically, pyroyl (manufactured by Yushi Co., Ltd.), Shin-Etsu Silicone (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like are available. As a method for forming the release layer, a known coating method such as a coating method using a roll coater such as a gravure roll or a spraying method using spray or the like can be adopted.

Hereinafter, the use of the surface protection sheet for laser processing of the present invention will be described.
FIG. 1 schematically shows the use of the surface protection sheet for laser processing of the present invention. The surface protection sheet 1 for laser processing of the present invention is attached to a workpiece 2 that is cut by irradiation with a laser beam 6. In the illustrated apparatus, the laser beam 6 is condensed by the condenser lens 31 of the processing head 3 and then irradiated onto the workpiece 2 from the nozzle 4. However, in the present invention, the laser beam generator is not limited to the illustrated one. From the nozzle 4, the assist gas 7 is sprayed onto the work 2 together with the laser beam 6 at a high pressure of about 0.5 to 1.5 MPa. The assist gas 7 is supplied from a gas supply means 5 such as a gas cylinder through an introduction pipe 51 and a gas introduction port 41. The assist gas 7 can be selected from various gases depending on the material of the workpiece 2 and the required cut surface quality. Typically, nitrogen gas or air is used.

  The workpiece 2 is an object to be cut and includes metal plates, painted metal plates, aluminum sashes, resin plates, decorative copper plates, vinyl chloride laminated steel plates, glass plates, etc. The effects of the present invention are particularly apparent in the case of a metal plate that is required to be present, particularly a stainless steel plate or an aluminum plate.

  The cutting process by irradiating the laser beam 6 is a process of cutting at least a part of the workpiece by forming a cutting portion that penetrates from one side of the workpiece 2 to the opposite side of the irradiation side of the laser beam 6. As shown in FIG. 2, it may be a process of removing a cylindrical portion, or a process of cutting a large workpiece into a plurality of small pieces. The surface protective sheet 1 for laser processing of the present invention is for sticking to the surface opposite to the laser beam irradiation surface 2a of the workpiece 2 to be processed in such cutting processing. In other words, the laser beam 6 is irradiated to the surface 2a opposite to the application surface of the workpiece 2 while the surface protection sheet 1 for laser processing of the present invention is applied to the workpiece 2, and cutting is performed. The surface protection sheet 1 for laser processing of the present invention is affixed to at least a portion of the work 2 opposite to the laser beam irradiation surface 2a that is cut by cutting. Of the workpiece 2, the surface to which the surface protection sheet for laser processing of the present invention is attached can be prevented from being damaged by being placed on a laser processing apparatus or the like, and dross is not easily generated.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail using an Example, these examples do not limit this invention at all.

Example 1
Acrylic adhesive (polystyrene equivalent weight average molecular weight) containing 2-ethylhexyl acrylate (2EHA) 30 wt%, ethyl acrylate (EA) 60%, methyl methacrylate (MMA) 6 wt%, 2-hydroxyethyl acrylate (HEA) 4 wt% An acrylic pressure-sensitive adhesive solution was obtained by adding 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., Coronate L) to an ethyl acetate solution containing 100 parts by weight of 600,000).
A polyethylene terephthalate film (Tetron film G2 manufactured by Teijin DuPont Co., Ltd.) having a thickness of 0.038 mm was used as it was as a base material layer. The resin material sampled from this base material layer had a melt viscosity at 290 ° C. of 74 Pa · s.
The acrylic pressure-sensitive adhesive solution was applied onto the above-described base material layer and dried to form a pressure-sensitive adhesive layer having a thickness of 0.010 mm, thereby obtaining a surface protective sheet for laser processing.

(Example 2)
A polybutylene terephthalate (Wintech Polymer Co., Ltd., DURANEX 200FP) was formed by a T-die method at a die temperature of 250 ° C. to obtain a base layer having a thickness of 0.04 mm. The resin material sampled from the base material layer had a melt viscosity at 290 ° C. of 26 Pa · s.
The acrylic pressure-sensitive adhesive solution used in Example 1 was applied to the base material layer and dried to form a pressure-sensitive adhesive layer having a thickness of 0.005 mm to obtain a surface protective sheet for laser processing.

(Example 3)
A surface protective sheet for laser processing was obtained in the same manner as in Example 1 except that a polyethylene terephthalate film having a thickness of 0.05 mm (Tetron film G2 manufactured by Teijin DuPont) was used as the base material layer.

Example 4
Low-density polyethylene (Mitsui Chemicals, Mirason 68P) is used as a material for the base layer, and 100 parts by weight of styrene / ethylene butylene / styrene block copolymer (Asahi Kasei Co., Ltd., Tuftec H1062) and water-added petroleum resin (Arakawa Chemical). Co., Ltd., Alcon P-100) containing 50 parts by weight is used as a material for the pressure-sensitive adhesive layer, and these are coextruded by a T-die method at a die temperature of 170 ° C. A surface protective sheet for laser processing was obtained in which an adhesive layer having a thickness of 0.01 mm was provided on the material layer. The resin material sampled from the base material layer had a melt viscosity at 290 ° C. of 47 Pa · s.

(Example 5)
A surface protective sheet for laser processing was obtained in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer was changed to 5 μm.

(Comparative Example 1)
A low-density polyethylene (Sumikasen F208, manufactured by Mitsui Chemicals, Inc.) was formed at a die temperature of 160 ° C. by an inflation method to obtain a substrate layer having a thickness of 0.11 mm. The resin material sampled from the base material layer had a melt viscosity at 290 ° C. of 285 Pa · s.
One side of this base material layer is subjected to a corona discharge treatment, and the acrylic pressure-sensitive adhesive solution used in Example 1 is applied to the treated surface and dried to form a pressure-sensitive adhesive layer having a thickness of 0.010 mm. A surface protective sheet for laser processing was obtained.

(Comparative Example 2)
A surface protective sheet for laser processing was obtained in the same manner as in Comparative Example 1 except that the thickness of the base material layer was 0.06 mm.

(Comparative Example 3)
A surface protective sheet for laser processing was obtained in the same manner as in Example 1 except that a 0.125 mm thick polyethylene terephthalate film (Tetoron Film G2 manufactured by Teijin Dupont) was used as the base material layer. The resin material sampled from this base material layer had a melt viscosity at 290 ° C. of 74 Pa · s as in Example 1.

(Comparative Example 4)
A base material layer having a thickness of 0.04 mm was obtained by forming a polypropylene film (Novatec PP FL6H, manufactured by Nippon Polypropylene Co., Ltd.) at a die temperature of 230 ° C. by the T-die method. The resin material sampled from this base material layer had a melt viscosity at 290 ° C. of 422 Pa · s.
One side of this base material layer is subjected to a corona discharge treatment, and the acrylic pressure-sensitive adhesive solution used in Example 1 is applied to the treated surface and dried to form a pressure-sensitive adhesive layer having a thickness of 0.010 mm. A surface protective sheet for laser processing was obtained.

(Comparative Example 5)
A polybutylene terephthalate (Wintech Polymer Co., Ltd., DURANEX 800FP) was formed by a T-die method at a die temperature of 270 ° C. to obtain a base layer having a thickness of 0.04 mm. The resin material sampled from the base material layer had a melt viscosity at 290 ° C. of 295 Pa · s.
The acrylic pressure-sensitive adhesive solution used in Example 1 was applied to one side of the base material layer and dried to form a pressure-sensitive adhesive layer having a thickness of 0.005 mm to obtain a surface protective sheet for laser processing.

(Measurement of melt viscosity)
The melt viscosity is measured by the method described above. Specifically, a capillary rheometer described in JIS K7199 (manufactured by Toyo Seiki Co., Ltd., Capillograph 1B) is used, the nozzle diameter D is 1.0 mm, and the land length L is 30 mm. The measurement was performed at a shear rate of 10 sec ⁻¹ .

(Laser cutting processing conditions)
Using a carbon dioxide laser processing machine (AMADA, LC-3015θII) and an oscillator (AMADA, OLC-420HII), cutting speed 2200 mm / min, output 3000 W, frequency 0 Hz, duty 100, nitrogen gas pressure 0.85 MPa, With a nozzle diameter of 2.0 mm and a nozzle gap of 0.3 mm, the laser beam was focused at a position 1.0 mm below the upper surface side of the workpiece (metal plate), and straight cutting was performed.

(Laser cutting test)
As a workpiece, SUS304 (2B finish) having a thickness of 2.0 mm was used, and the surface protective sheet for laser processing obtained in each of Examples and Comparative Examples was attached to one surface thereof. A cutting test was performed by irradiating the surface opposite to the surface on which the sheet was applied with the laser beam under the above-described conditions. After the test, the height of dross generated on the surface to which the sheet was attached was measured. The value obtained by subtracting the thickness (2.0 mm) of the metal plate from the height of the cut end face was taken as the height of the dross. As a measuring instrument, a dial gauge having a scale of 0.01 mm described in JIS B7503 (1997) was used, and measurement was performed at 10 locations at intervals of 10 mm, and the average value was obtained. The results are shown in Table 1.

In addition, a sample in which the surface protective sheet for laser processing obtained in Example 5 was attached to one side of the work and SPV-M-4002E (manufactured by Nitto Denko) was attached to the other side of the work was used in Example 6. It was. In Example 6, the cutting process test was performed by irradiating the surface on which M-4002E was affixed with the laser beam under the above-described conditions.
In addition, what was used for the laser cutting process without sticking a surface protection sheet was set as the comparative example 6.

  As shown in Table 1, it has been clarified that the surface protection sheet for laser processing of each example can reduce the height of dross to the same extent as the example in which the surface protection sheet is not attached.

The use of the surface protection sheet for laser processing of the present invention is schematically shown. It is explanatory drawing of the dross produced by a laser cutting process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface protection sheet for laser processing 2 Work 3 Processing head 31 Condensing lens 4 Nozzle 41 Gas inlet 5 Gas supply means 51 Introducing pipe 6 Laser beam 7 Assist gas 100 Surface protection sheet 200 Work 210 Dross 300 Through-hole

Claims (7)

The carbon dioxide gas laser beam, the workpiece made of a metal plate, the assist gas the work laser beam irradiation surface opposite the laser machining for surface protection sheet is attached to the surface of the when performing cutting by irradiation under the supply of Because
A base material layer and a pressure-sensitive adhesive layer provided on one side thereof. The base material layer is made of a resin material having a melt viscosity of 200 Pa · s or less measured at 290 ° C. based on JIS K7199 (1999). The surface protection sheet for laser processing whose thickness of a material layer is 0.01-0.12 mm.   The surface protective sheet for laser processing according to claim 1, wherein the resin material is a polyester resin.   The surface protective sheet for laser processing according to claim 2, wherein the polyester resin is a polyethylene terephthalate resin.   The surface protection sheet for laser processing according to claim 1, wherein the resin material is made of a polyolefin-based resin. Laser processing for surface protection sheet of claim 1, wherein the metal plate is a stainless steel plate. Laser processing for surface protection sheet of claim 1, wherein the metal plate is an aluminum plate. A laser processing method for performing a cutting process by irradiating a workpiece made of a metal plate with a carbon dioxide gas laser beam while supplying an assist gas ,
J IS K7199 melt viscosity measured at 290 ° C. Based on the (1999) is made of a resin material or less 200 Pa · s, the pressure-sensitive adhesive layer on one side of the substrate layer having a thickness Saga 0.01~0.12mm is The provided surface protection sheet
A laser processing method, wherein the workpiece is attached to a surface opposite to a laser beam irradiation surface of the workpiece .

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