Blade of wind power generator, wind power generator, and installation method of protection film for blade of wind power generator

Abstract

To provide a blade of a wind power generator to which a protection film is applied and which is sufficiently protected even after a certain time elapses when the protection film is applied to the blade of the wind power generator.SOLUTION: A protection film 10 is applied to a blade body 23. One end side e1 of the protection film 10 has an end side overlapping part W2 which overlaps with an end side e2 of an adjacent protection film 10 and consequently the protection film 10 has the end side overlapping part W2. The end side overlapping part W2 prevents a gap from occurring between the protection film 10 and the adjacent protection film 10 even when temporal shrinkage, caused due to the protection film 10 being applied in a stretching manner during installation of the protection film 10, occurs in the protection film 10. Thus, even if cracks etc. occur in the blade body 23, moisture is prevented from entering the inside of the blade through the gap to prevent deterioration of the blade body.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a blade of a wind power generation device, a wind power generation device, and a method for applying a protective film for the blade of a wind power generation device.

Background Art

[0002] The blades of wind power generation devices are exposed to ultraviolet rays from sunlight, wind, rain, snow, sleet, hail, lightning, seawater, gas, sand, dust, dirt, etc. In addition, the blades of wind power generation devices may also be affected by collisions with birds, insects, flying objects, etc. Thus, since the blades are in a harsh environment, problems such as damage, deformation, surface contamination, and surface peeling occur due to long-term use. In addition, since the blades are rotating at high speed, the possibility of damage, deformation, surface contamination, and surface peeling also increases. These problems lead to a decrease in power generation efficiency. In the worst case, the blades may break or fall off.

[0003] Therefore, in order to protect the blades, techniques have been proposed in which a protective film or a protective cover is disposed on the surface of the blade, particularly on the edge portion of the blade (Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generally, when applying a protective film to the blade of a wind power generation device, the film is cut into a predetermined size (for example, A4 size, etc.), and the cut protective film is arranged on the blade such that the edges of two adjacent protective films contact each other, and then bonded together.

[0006] However, even when the films are adhered to each other without leaving a gap, a gap may occur between the two protective films over time. This is because when the protective film is adhered to the blade, the protective film needs to be stretched to some extent during adhesion, and thus the protective film may shrink over time.

[0007] In this way, when a gap occurs between the protective films, moisture and the like may penetrate through this gap. If there are cracks or the like in the blade, moisture may penetrate into the blade through these cracks, and deterioration inside the blade may occur.

[0008] Also, usually, in the blade of a wind power generation device, the edge portion of the blade is most affected by impacts such as collisions with birds, insects, and flying objects. Therefore, it is particularly necessary to focus on protecting the edge portion.

[0009] The present disclosure has been made in view of the above circumstances, and the main object is to provide a blade of a wind power generation device to which a protective film is adhered, and even after a lapse of time, the blade is sufficiently protected by the adhered protective film.

Means for Solving the Problems

[0010] One embodiment of the present disclosure is a blade of a wind power generation device having a blade body, a protective film adhered to the surface of the blade body, and an adhesive layer disposed on one surface of the protective layer, wherein at least two of the protective films for the blade are adhered so as to overlap each other.

[0011] Other embodiments of the present disclosure include a blade for a wind power generation device having a blade body, a protective film adhered to the surface of the blade body, and an adhesive layer disposed on one surface of the protective film, wherein the protective film for the blade is adhered at least to the edge portion of the blade of the wind power generation device, and the thickness of the protective film disposed on the rotation center side of the blade of the wind power generation device is thinner than the thickness of the protective film disposed on the side opposite to the rotation center of the blade of the wind power generation device.

[0012] Other embodiments of the present disclosure provide a wind power generation device including the blade of the wind power generation device described above.

[0013] Other embodiments of the present disclosure provide a method for applying a protective film for a blade, which involves applying the protective film for the blade to the blade, and obtaining the blade of the wind power generation device described above through the application step.

Advantages of the Invention

[0014] In the present disclosure, there is an effect that even after a lapse of time, a blade of a wind power generation device with a protective film adhered thereto, which provides sufficient protection for the blade, can be provided.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be implemented in many different modes and is not construed as being limited to the description of the embodiments exemplified below. In addition, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual form, but this is merely an example and the interpretation of the present disclosure should not be limited. Also, in this specification and each figure, elements that are the same as those described above with respect to the already shown figures may be denoted by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0017] In this specification, when expressing the mode of arranging one member on another member, when simply described as "on" or "under", unless otherwise specified, it includes both the case of arranging another member directly above or directly below so as to be in contact with a certain member and the case of arranging another member above or below a certain member via still another member. Also, in this specification, when expressing the mode of arranging one member on the surface of another member, when simply described as "on the surface side" or "on the surface", unless otherwise specified, it includes both the case of arranging another member directly above or directly below so as to be in contact with a certain member and the case of arranging another member above or below a certain member via still another member.

[0018] Also, in this specification, "film" includes a member called "sheet".

[0019] Hereinafter, the blade of the wind power generation device, the wind power generation device, the construction method of the protective film for the blade, and the protective film for preventing gaps in the present disclosure will be described in detail.

[0020] A. Blade of Wind Power Generation Device The blade of the wind power generation device of the present disclosure includes a blade body, a protective film adhered to the surface of the blade body, and an adhesive layer disposed on one surface of the protective film. The blade of the wind power generation device has a protective film for the blade, and at least two of the protective films for the blade are adhered so as to overlap each other.

[0021] FIG. 1(a) is a schematic perspective view showing an example of the blade in the present disclosure, and FIG. 1(b) is a cross-sectional view taken along line A-A of FIG. 1(a). In FIG. 1(a), a protective film 10 is disposed at the tip 22 of the leading edge (which may be referred to as the edge portion) 21 of the blade 20. As shown in FIG. 1(b), at the edge portion 21, an edge portion overlapping portion W1 is formed in which an overlapping portion film 14 overlaps on the surface of the protective film 10.

[0022] By having the above-described configuration, the blade of the wind power generation device of the present disclosure can provide a blade of a wind power generation device to which a protective film that sufficiently protects the blade is adhered even after a lapse of time. In this example, by providing the edge portion overlapping portion W1 at the edge portion 21, which is most affected by impacts such as collisions with birds, insects, and flying objects, the blade can be sufficiently protected even after a lapse of time.

[0023] The blade of the present disclosure has three embodiments. Each will be described below. In this specification, the "blade of the wind power generation device" may be simply abbreviated as "blade". Also, the "protective film for the blade" may be simply referred to as "protective film".

[0024] A-1. First Embodiment The first embodiment of the blade of the wind power generation device of the present disclosure has a blade body, a protective film adhered to the surface of the blade body, and an adhesive layer disposed on one surface of the protective film, and a protective film for the blade, wherein the protective film is adhered so as to have an edge overlapping portion where one edge overlaps the opposite edge of another adjacent protective film.

[0025] FIG. 2 is a schematic cross-sectional view illustrating the blade in this embodiment. The protective film 10 in FIG. 2 is adhered to the blade body 23, and has an edge overlapping portion W2 where one edge e1 of the protective film 10 overlaps on the edge e2 of the adjacent protective film 10.

[0026] In this embodiment, since the protective film 10 has the edge overlapping portion W2 as described above, even when the protective film 10 shrinks over time due to being stretched and adhered during the construction of the protective film, no gap will occur between the adjacent protective films 10. Therefore, even if there are cracks or the like in the blade body 23, moisture will not penetrate through the gap, so that deterioration of the blade body can be prevented.

[0027] In this embodiment, it is sufficient to have an edge overlapping portion that overlaps so as to ride on the opposite edge of another adjacent protective film at least on one edge. As shown not only in the example of FIG. 2 but also in FIG. 3, both edges e1 of the protective film 10 may have an edge overlapping portion W2 that overlaps so as to ride on the edge e2 of another protective film 10 respectively.

[0028] In this embodiment, the lower limit of the distance of the edge overlapping portion is preferably 0.1 cm or more, particularly preferably 0.5 cm or more, and most preferably 1 cm or more. On the other hand, the upper limit of the distance of the edge overlapping portion is preferably 100 cm or less, particularly preferably 50 cm or less, and most preferably 10 cm or less.

[0029] In addition, in the present embodiment, it is preferable that the above-mentioned edge overlapping portion is arranged in a direction intersecting the edge portion of the blade.

[0030] Since the protective film is regarded as playing an important role in protecting the edge portion of the blade, it is necessary to continuously arrange the protective film on the edge portion. For this reason, by arranging the edge of the adjacent protective film so as to face the edge intersecting the edge of the protective film and providing an edge overlapping portion, the protective film can be continuously arranged along the edge portion.

[0031] Hereinafter, the blade of the present embodiment will be described separately for the protective film and the blade body.

[0032] 1. Protective film The protective film in the present embodiment has a protective layer 1 as shown in FIG. 4 and an adhesive layer 2 disposed on one surface of the protective layer 1. Hereinafter, each will be described.

[0033] (1) Protective layer a) Shape of the protective layer The lower limit of the thickness of the protective layer in the present embodiment is not particularly limited, but it is preferably 10 μm or more, particularly preferably 30 μm or more, and most preferably 50 μm or more. On the other hand, the upper limit of the thickness is preferably 1000 μm or less, particularly preferably 900 μm or less, and most preferably 800 μm or less.

[0034] b) Physical properties of the protective layer (A) Tensile modulus In this embodiment, the tensile elastic modulus of the protective layer is 35 MPa or less, and may be 30 MPa or less, 20 MPa or less, or 15 MPa or less. When the tensile elastic modulus of the protective layer is within the above range, the protective layer is soft, easy to stretch, and tends not to deform. Therefore, when wind, rain, snow, sleet, hail, seawater, sand, dust, dirt, birds, insects, flying objects, etc. collide with the surface of the blade having the protective film, the impact can be absorbed by the protective layer of the protective film. Thus, the occurrence of erosion can be suppressed. In addition, the followability to the curved surface of the blade can be improved. On the other hand, the tensile elastic modulus of the protective layer is 5 MPa or more, and may be 7 MPa or more, or 10 MPa or more. If the tensile elastic modulus of the protective layer is too low, the protective layer may become too soft, resulting in a possible decrease in erosion resistance or difficulty in handling the protective film. Specifically, the tensile elastic modulus of the protective layer is 5 MPa or more and 35 MPa or less, and may be 5 MPa or more and 30 MPa or less, 7 MPa or more and 20 MPa or less, or 10 MPa or more and 15 MPa or less.

[0035] The tensile elastic modulus is measured using a tensile testing machine in accordance with ISO 527-3:2018. However, the tensile elastic modulus is taken as the slope by the least squares method corresponding to the two points of 5% strain and 10% strain in the stress-strain curve. The specific measurement conditions are shown below.

[0036] <Measurement Conditions> · Test piece: Strip-shaped · Test piece size: Width 10 mm, length 80 mm · Gauge length: 25 mm · Tensile speed: 100 mm / min · Test conditions: Temperature 25°C, humidity 50%RH · Number of test pieces: Measurement is performed with 3 test pieces, and the arithmetic mean value is adopted.

[0037] When measuring the tensile elastic modulus of the protective layer, the adhesive layer is removed from the protective film, and the protective layer is taken out. Examples of the method for removing the adhesive layer include dissolving the adhesive layer with a solvent. As the solvent, a solvent contained in the adhesive composition used for forming the adhesive layer can be used.

[0038] (a) Tensile fracture stress In this embodiment, the tensile fracture stress of the protective layer is, for example, 5 MPa or more, may be 7 MPa or more, or may be 10 MPa or more. By the tensile fracture stress of the protective layer being within the above range, the durability can be improved. On the other hand, the tensile fracture stress of the protective layer is, for example, 35 MPa or less, may be 30 MPa or less, or may be 20 MPa or less. If the tensile fracture stress of the protective layer is too large, the protective film becomes difficult to stretch, and there is a possibility that the followability to the curved surface of the blade decreases. Specifically, the tensile fracture stress of the protective layer is 5 MPa or more and 35 MPa or less, may be 7 MPa or more and 30 MPa or less, or may be 10 MPa or more and 20 MPa or less.

[0039] The tensile fracture stress is measured using a tensile testing machine in accordance with ISO 527-3:2018. The tensile fracture stress is the stress at the break of the test piece. The tensile test for measuring the tensile fracture stress is the same as the tensile test for measuring the above-mentioned tensile elastic modulus.

[0040] (c) Tensile fracture elongation In this embodiment, the tensile fracture elongation of the protective layer is preferably, for example, 800% or more, may be 1000% or more, or may be 1200% or more. By the tensile fracture elongation of the protective layer being within the above range, the durability can be improved. On the other hand, the upper limit of the tensile fracture elongation of the protective layer is not particularly limited, but is, for example, 3500% or less, may be 3000% or less, or may be 2500% or less. Specifically, the tensile fracture elongation of the protective layer is 800% or more and 3500% or less, may be 1000% or more and 3000% or less, or may be 1200% or more and 2500% or less.

[0041] The tensile fracture elongation is measured using a tensile testing machine in accordance with ISO 527-3:2018. The tensile fracture elongation is the elongation at the break of the test piece. The tensile test for measuring the tensile fracture elongation is the same as the tensile test for measuring the above-mentioned tensile modulus of elasticity.

[0042] (E) Type A durometer hardness In the present embodiment, the Type A durometer hardness of the protective layer is preferably, for example, 95 or less, may be 90 or less, and may be 85 or less. When the Type A durometer hardness of the protective layer is within the above range, the protective layer tends to be relatively soft. Therefore, the protective layer of the protective film can absorb the impact caused by the collision with the blade, so that the occurrence of erosion can be suppressed. In addition, the followability to the curved surface of the blade can be improved. On the other hand, the Type A durometer hardness of the protective layer is, for example, 60 or more, may be 65 or more, and may be 70 or more. If the durometer A hardness of the protective layer is too low, the protective layer becomes too soft, and there is a possibility that the erosion resistance decreases or the handling of the protective film becomes difficult. Specifically, the Type A durometer hardness of the protective layer is 60 or more and 95 or less, may be 65 or more and 90 or less, and may be 70 or more and 85 or less.

[0043] The Type A durometer hardness is measured using a hardness tester in accordance with JIS K6253-3:2012. However, when measuring by stacking test pieces, the number of test pieces stacked is not limited. For example, when the thickness of the protective layer is 300 μm, 20 test pieces are stacked. Specific measurement conditions are shown below.

[0044] <Measurement conditions> Thickness of test piece: 6 mm Test conditions: 23°C, 50% RH Measurement time: 3 seconds

[0045] (C) Water vapor permeability In the present embodiment, the water vapor permeability of the protective layer is preferably, for example, 15.0 g / (m 2 ·24 h) or less, and may be 10.0 g / (m 2· Preferably, it is 5.0 g / (m·24 h) or less, more preferably 2 · 4.0 g / (m·24 h) or less, and even more preferably 2 · It may be 3.0 g / (m·24 h) or less. By having the water vapor 2 transmittance of the protective layer within the above range,

[0046] the ingress of moisture into the blade can be suppressed.

[0047] Thus, corrosion and damage of the blade and deterioration of

[0048] (g) Total light transmittance In this embodiment, the total light transmittance of the

[0049] The total light transmittance is measured in accordance with ISO 13468-1:1996.

[0050] (c) Contact angle of water In this embodiment, the protective layer preferably has hydrophobicity. It can suppress the adhesion of moisture to the blade. Thereby, in the blade, dew condensation due to temperature change, adhesion of rain, snow deposition, and ice formation can be suppressed. Therefore, a decrease in power generation efficiency can be suppressed. Also, the intrusion of moisture into the blade can be suppressed. Therefore, corrosion and damage of the blade and deterioration of insulation of the electrical system can be suppressed.

[0051] Specifically, the contact angle of water on the surface of the protective layer is preferably 90° or more, may be 95° or more, and may be 100° or more. By the contact angle being within the above range, the adhesion of moisture to the blade can be suppressed. On the other hand, the upper limit of the contact angle of water on the surface of the protective layer is not particularly limited, but is, for example, 120° or less. If the contact angle is too high, the adhesion to the adhesive layer and the surface layer described later may decrease. The contact angle of water on the surface of the protective layer is, for example, 90° or more and 120° or less, may be 95° or more and 120° or less, and may be 100° or more and 120° or less.

[0052] The contact angle of water is measured in accordance with JIS R3257:1999 by the sessile drop method using a contact angle meter. Specifically, 2 μL of a droplet of pure water is dropped onto the surface of the protective layer of the protective film, and the contact angle of water 1 second after droplet landing is measured. The atmosphere is at a temperature of 25°C and a humidity of 50%RH. The contact angle of water is calculated by the θ / 2 method.

[0053] Generally, polyolefin-based resins have hydrophobicity and tend to have a high contact angle of water.

[0054] (e) Gel fraction When the protective layer contains a crosslinked polyolefin-based resin or a non-crosslinked polyolefin-based resin as described later, the degree of crosslinking can be indicated by the gel fraction.

[0055] When the protective layer contains a non-crosslinked polyolefin resin, the gel fraction of the protective layer is usually 5% or less, preferably 0%.

[0056] On the other hand, when the protective layer contains a crosslinked polyolefin resin, the gel fraction of the protective layer is preferably, for example, 30% or more, more preferably 40% or more. Also, in this case, the gel fraction of the protective layer is preferably 90% or less, more preferably 80% or less. Specifically, the gel fraction of the protective layer is preferably 30% or more and 90% or less, more preferably 40% or more and 80% or less.

[0057] In this specification, the gel fraction (%) is measured by the following method. First, 1.0 g of the protective layer is placed in a resin mesh and extracted with xylene at 110 °C for 24 hours. Then, the entire resin mesh is taken out, dried, and weighed. Next, the mass before and after extraction is compared to measure the mass percentage of the residual insoluble matter. And the mass percentage of the residual insoluble matter is taken as the gel fraction.

[0058] Note that a gel fraction of 0% means that the above-mentioned residual insoluble matter is substantially 0 and the crosslinking reaction of the resin composition has not substantially started. More specifically, a gel fraction of 0% means the case where the above-mentioned residual insoluble matter is completely absent and the case where the mass percentage of the above-mentioned residual insoluble matter measured by a precision balance is less than 0.05 mass%.

[0059] In addition, the above-mentioned residual insoluble matter does not contain pigment components other than the resin component. When these mixtures other than the resin component are mixed in the residual insoluble matter by the above test, for example, by separately measuring the content of these mixtures in the resin component in advance, the gel fraction that should be originally obtained for the residual insoluble matter derived from the resin component excluding these mixtures can be calculated.

[0060] c) Material of the protective layer The material of the protective layer in this embodiment is not particularly limited as long as it is a material usually used for the protective film for the blade. Examples thereof include polyurethane resins and polyolefin resins.

[0061] In this embodiment, it is preferably a polyolefin resin among others. This is because polyolefin resins have high durability, making it possible to suppress a decrease in the performance of the protective film due to deterioration over time.

[0062] (A) Polyolefin resin The polyolefin resin may be obtained by polymerizing only olefins, or may be obtained by copolymerizing an olefin and a monomer other than olefins. That is, the polyolefin resin may be composed of only olefins, or may be composed of an olefin and a monomer other than olefins. Among others, it is preferable that the polyolefin resin is composed of only olefins.

[0063] Examples of the polyolefin resin include polyethylene resins and polypropylene resins. Among others, a polyethylene resin is preferable.

[0064] The polyethylene resin may be a homopolymer of ethylene, a copolymer of ethylene and an α-olefin, or a copolymer of ethylene and a monomer other than olefins.

[0065] In the copolymer of ethylene and an α-olefin, the α-olefin is preferably an α-olefin having 3 to 12 carbon atoms. Specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene-1 can be mentioned. The α-olefin may be used alone or in combination of two or more. Among others, an α-olefin having no branch is preferable, and an α-olefin having no branch and having 3 to 8 carbon atoms is more preferable. Specifically, 1-propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene can be mentioned. When the α-olefin has 3 to 8 carbon atoms, good flexibility and good strength can be imparted.

[0066] Specific examples of the copolymer of ethylene and an α-olefin include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, and ethylene-4-methyl-pentene-1 copolymer.

[0067] Specific examples of the copolymer of ethylene and a monomer other than an olefin include ethylene-vinyl acetate copolymer.

[0068] Examples of the polyethylene-based resin include high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), metallocene-based linear low-density polyethylene (M-LLDPE), and very low-density polyethylene (VLDPE). The polyethylene-based resin may be used alone or in combination of two or more.

[0069] Among them, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), metallocene-based linear low-density polyethylene (M-LLDPE), and very low-density polyethylene (VLDPE) are preferred. They have good flexibility, transparency, and processability. Since they can impart good flexibility to the protective layer, the protective layer of the protective film can absorb the impact caused by the collision with the blade and suppress the occurrence of erosion. In addition, the followability to the curved surface of the blade can be improved.

[0070] Metallocene-based linear low-density polyethylene (M-LLDPE) is synthesized using a metallocene catalyst which is a single-site catalyst. In such a polyethylene-based resin, there are few side-chain branches and the distribution of the comonomer is uniform. Therefore, the molecular weight distribution is narrow and it is possible to achieve a low density, and flexibility and strength can be imparted. In addition, the crystalline distribution is narrow and the crystal sizes are uniform. Therefore, not only are there no large crystal sizes, but also the crystallinity itself is low due to the low density. For this reason, it has excellent transparency.

[0071] The density of the polyethylene-based resin is not particularly limited. The density of the polyethylene-based resin is, for example, 0.950 g / cm 3 or less, and may be 0.930 g / cm 3 or less, may be 0.925 g / cm 3 or less, and may be 0.920 g / cm 3 or less. By the density of the polyethylene-based resin being within the above range, flexibility, transparency, and processability can be improved. Since good flexibility can be imparted to the protective layer, the protective layer of the protective film can absorb the impact caused by the collision with the blade, and the occurrence of erosion can be suppressed. Also, the followability to the curved surface of the blade can be improved. Further, by the density of the polyethylene-based resin being within the above range, the unit weight of the protective layer can be reduced, and the weight reduction of the protective film can be achieved. On the other hand, the density of the polyethylene-based resin is, for example, 0.850 g / cm 3 or more, and may be 0.870 g / cm 3 or more. That is, the density of the polyethylene-based resin is, for example, 0.850 g / cm 3 or more and 0.950 g / cm 3 or less, may be 0.850 g / cm 3 or more and 0.930 g / cm 3 or less, may be 0.870 g / cm 3 or more and 0.925 g / cm 3 or less, may be 0.870 g / cm 3 or more and 0.920 g / cm 3 or less.

[0072] The density of the polyethylene-based resin is measured by the pycnometer method in accordance with ISO 1183:2019.

[0073] The melting point of the polyethylene-based resin is not particularly limited. For example, the melting point of the polyethylene-based resin is 100°C or lower. In the case of polyolefin-based resins, if the melting point is low, it tends to become soft. Therefore, if the melting point is within the above range, good flexibility can be imparted to the protective layer. Thus, the protective layer of the protective film can absorb the impact caused by the collision with the blade and suppress the occurrence of erosion. In addition, the followability to the curved surface of the blade can be improved. On the other hand, the melting point of the polyethylene-based resin is, for example, 50°C or higher, and may be 60°C or higher. If the above melting point is too low, the heat resistance may decrease.

[0074] The melting point of the resin is measured by a differential scanning calorimeter (DSC) in accordance with ISO 3146:2000. When there are two or more melting point peaks, the higher temperature is taken as the melting point.

[0075] The melt mass flow rate (MFR) of the polyethylene-based resin at a temperature of 190°C is preferably, for example, 1 g / 10 min or more and 30 g / 10 min or less, more preferably 1 g / 10 min or more and 25 g / 10 min or less, and even more preferably 1 g / 10 min or more and 20 g / 10 min or less. When the MFR of the polyethylene-based resin is below a predetermined value, the strength can be improved. In addition, when the MFR of the polyethylene-based resin is within the above range, the film-forming property and flexibility can be improved.

[0076] The melt mass flow rate (MFR) of the polyethylene-based resin is measured in accordance with ISO 1133-1:2011. The measurement conditions are Method A, temperature 190°C, and load 2.16 kg.

[0077] The polyethylene-based resin preferably does not contain an ester bond. Excellent hydrolysis resistance can be obtained.

[0078] In addition, the polyolefin-based resin may be a crosslinked polyolefin-based resin or a non-crosslinked polyolefin-based resin. Also, the polyethylene-based resin may be a crosslinked polyethylene-based resin or a non-crosslinked polyethylene-based resin.

[0079] The crosslinked polyolefin resin refers to a crosslinked polyolefin resin, that is, a polyolefin resin having crosslinking bonds. On the other hand, the non-crosslinked polyolefin resin refers to a non-crosslinked polyolefin resin.

[0080] The crosslinked polyethylene resin refers to a crosslinked polyethylene resin, that is, a polyethylene resin having crosslinking bonds. On the other hand, the non-crosslinked polyethylene resin refers to a non-crosslinked polyethylene resin.

[0081] As a crosslinking method for crosslinking polyolefin resins, general crosslinking methods can be applied. For example, there are crosslinking methods using crosslinking agents, silane crosslinking methods by silanol condensation, and crosslinking methods by irradiation with ionizing radiation. Among them, the crosslinking method using a crosslinking agent is preferred.

[0082] As the crosslinking agent, general crosslinking agents can be used. For example, organic peroxides can be mentioned. Examples of organic peroxides include peroxycarbonates, peroxyketals, and dialkyl peroxides. Examples of peroxycarbonates include t-amyl-peroxy-2-ethylhexyl carbonate and t-butyl peroxy 2-ethylhexyl carbonate. Examples of peroxyketals include n-butyl 4,4-di(t-butylperoxy)valerate, ethyl 3,3-di(t-butylperoxy)butyrate, and 2,2-di(t-butylperoxy)butane. Examples of dialkyl peroxides include di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(t-peroxy)hexyne-3. The crosslinking agent may be used alone or in combination of two or more.

[0083] In the resin composition used for forming the protective layer, the content of the crosslinking agent is appropriately selected according to the target degree of crosslinking and the like.

[0084] Also, in the crosslinking method using a crosslinking agent, a crosslinking aid may be used. By using a crosslinking aid, an appropriate crosslinking reaction can be promoted. Furthermore, since the crosslinking aid reduces the crystallinity of the polyolefin resin, transparency can be maintained. As the crosslinking aid, general crosslinking aids can be used, and examples include polyfunctional monomers having polymerizable functional groups.

[0085] Among them, from the viewpoint of improving reactivity, the crosslinking aid is preferably a nurate ring-containing compound having two or more polymerizable functional groups in one molecule.

[0086] In the crosslinking aid, the number of polymerizable functional groups is preferably, for example, 2 or more and 6 or less in one molecule, and more preferably 2 or more and 3 or less in one molecule. If the number of polymerizable functional groups is too small, there is a possibility that the crosslinking density cannot be sufficiently increased. On the other hand, if the number of polymerizable functional groups is too large, it may adversely affect the physical properties of the protective layer, such as making the protective layer brittle after the crosslinking treatment.

[0087] The polymerizable functional group is not particularly limited as long as it can react with the polyolefin resin as the base resin to impart a crosslinked structure. Among them, groups having a carbon-carbon double bond, epoxy groups, etc. are preferable. Examples of the group having a carbon-carbon double bond include a vinyl group, a (meth)acryloyl group, a (meth)acryloyloxy group, and an allyl group.

[0088] Examples of the crosslinking aid include polyallyl compounds, poly(meth)acryloxy compounds, and epoxy compounds. Examples of the polyallyl compounds include triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, and diallyl maleate. Examples of the poly(meth)acryloxy compounds include trimethylolpropane trimethacrylate (TMPT), trimethylolpropane triacrylate (TMPTA), ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, and 1,9-nonanediol diacrylate. Examples of the epoxy compounds include epoxy compounds containing a double bond and an epoxy group, and epoxy compounds containing two or more epoxy groups. Examples of the epoxy compounds containing a double bond and an epoxy group include glycidyl methacrylate and 4-hydroxybutyl acrylate glycidyl ether. Examples of the epoxy compounds containing two or more epoxy groups include 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and trimethylolpropane polyglycidyl ether. The crosslinking aid may be used alone or in combination of two or more kinds.

[0089] Among them, it is preferable to use triallyl isocyanurate (TAIC) as the crosslinking aid. Triallyl isocyanurate (TAIC) has good compatibility with linear low-density polyethylene and can reduce crystallinity and maintain transparency by crosslinking. Furthermore, triallyl isocyanurate (TAIC) can impart flexibility at low temperatures to the protective layer.

[0090] In the resin composition used for forming the protective layer, the content of the crosslinking aid is appropriately selected according to the target degree of crosslinking and the like.

[0091] The content of the polyolefin resin is preferably, for example, 90 parts by mass or more, more preferably 95 parts by mass or more, based on 100 parts by mass of all the resin components contained in the protective layer. Thereby, transparency and flexibility can be improved.

[0092] The ratio of each resin component contained in the protective layer is analyzed from the peak ratio detected by differential scanning calorimetry (DSC).

[0093] (i) Additives The protective layer may contain additives as necessary. Examples of the additives include light stabilizers, ultraviolet absorbers, antioxidants, heat stabilizers, nucleating agents, dispersants, leveling agents, plasticizers, defoaming agents, flame retardants, and fillers. Among them, it is preferable that the protective layer contains weathering agents. Examples of the weathering agents include light stabilizers, ultraviolet absorbers, antioxidants, etc.

[0094] Examples of the light stabilizer include hindered amine light stabilizers (HALS). Hindered amine light stabilizers are roughly classified into three types according to the bonding partner of the nitrogen atom in the piperidine skeleton: N-H type (hydrogen is bonded to the nitrogen atom), N-R type (alkyl group (R) is bonded to the nitrogen atom), and N-OR type (alkoxy group (OR) is bonded to the nitrogen atom). Among them, the N-OR type hindered amine light stabilizer is preferable. The N-OR type captures radicals faster than the N-H type and N-R type. Furthermore, the low molecular weight HALS of the N-OR type that migrates to the surface faster than the polymer HALS captures radicals in a shorter period. Therefore, deterioration of the protective layer can be suppressed. 3 type of HALS captures radicals in a shorter period. Therefore, deterioration of the protective layer can be suppressed.

[0095] Weathering agents such as the above light stabilizers, ultraviolet absorbers, and antioxidants may be added to the resin composition as a weathering masterbatch dispersed in the resin. The weathering masterbatch may be appropriately prepared or a commercially available product may be used. The resin used for the weathering masterbatch may be the above polyolefin resin or other resins.

[0096] The content of the additive in the protective layer is, for example, 5% by mass or less.

[0097] d) Layer structure of the protective layer The protective layer may have at least a polyolefin resin film containing a polyolefin resin. The protective layer may be a single layer composed of a polyolefin resin film, or may be a multilayer having a polyolefin resin film. When the protective layer has a plurality of polyolefin resin films, the polyolefin resins contained in each polyolefin resin film may be the same or different. Further, in the case of a multilayer, the protective layer may have a surface film containing a cured product of an electron beam curable resin composition, which is disposed on the surface opposite to the adhesive layer of the polyolefin resin film.

[0098] (A) Surface film The protective layer 1 may have a surface film containing a cured product of an electron beam curable resin composition, which is disposed on the surface opposite to the adhesive layer of the polyolefin resin film. By having a surface film on the protective layer, the durability can be further improved.

[0099] The electron beam curable resin composition contains at least an electron beam curable resin. As the electron beam curable resin, it can be appropriately selected from polymerizable monomers, polymerizable oligomers, and polymerizable prepolymers and used.

[0100] The surface film may contain an ultraviolet absorber. As will be described later, when no primer film is disposed between the polyolefin resin film and the surface film, it is preferable that the surface film contains an ultraviolet absorber. On the other hand, when a primer film is disposed between the polyolefin resin film and the surface film, it is preferable that at least one of the surface film and the primer film contains an ultraviolet absorber.

[0101] The ultraviolet absorber may be either an inorganic ultraviolet absorber or an organic ultraviolet absorber.

[0102] Inorganic ultraviolet absorbers are preferably, for example, titanium oxide, cerium oxide, and zinc oxide having an average particle size of about 5 nm or more and 120 nm or less.

[0103] Examples of organic ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, and acrylonitrile-based ultraviolet absorbers. Examples of benzotriazole-based ultraviolet absorbers include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, and polyethylene glycol 3-[3-(benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl]propionate. Examples of triazine-based ultraviolet absorbers include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]phenol, 1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1,3,5-tri[[3,5-bis-(1,1-dimethylethyl)-4-hydroxyphenyl]methyl].

[0104] The surface film may contain additives other than the ultraviolet absorber, if necessary.

[0105] In order to impart weather resistance to the surface film, a light stabilizer may be used in combination with the ultraviolet absorber. Examples of the light stabilizer include hindered amine-based light stabilizers. Specifically, 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2'-n-butyl malonic acid bis(1,2,2,6,6-pentamethyl-4-piperidyl), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, etc. may be mentioned.

[0106] Examples of other additives include abrasion resistance improvers, polymerization inhibitors, crosslinking agents, infrared absorbers, antistatic agents, adhesion improvers, leveling agents, thixotropy imparting agents, coupling agents, plasticizers, defoaming agents, fillers, solvents, and colorants.

[0107] (a) Primer film The protective layer may have a primer film between the above polyolefin resin film and the above surface film. It can improve the adhesion between the polyolefin resin film and the surface film.

[0108] e) Method for forming the protective layer The protective layer can be obtained, for example, by mixing the above components to prepare a resin composition, melting the resin composition, and forming it into a sheet. Further, a crosslinking treatment may be performed after film formation.

[0109] Examples of the method for mixing the components include a method of impregnating the polyolefin resin with each component by dry blending. When obtaining the protective layer by extrusion molding, a crosslinking agent or a crosslinking aid may be added to the polyolefin resin in a liquid state. Also, a crosslinking aid may be kneaded in advance with the polyolefin resin and used in the form of a masterbatch as a mixture. When using a masterbatch, the dispersibility of the crosslinking aid is improved.

[0110] As the melt molding method, any general molding method may be used. Examples include injection molding, extrusion molding, blow molding, compression molding, rotational molding, etc. The molding temperature may be a temperature exceeding the melting point of the above resin composition. Also, the molding temperature may be a temperature at which crosslinking does not start during film formation according to the crosslinking agent, that is, a temperature at which the gel fraction of the resin composition can be maintained at 0%. The molding temperature is, for example, 80°C or higher and 250°C or lower.

[0111] Examples of the crosslinking treatment include crosslinking treatment with a crosslinking agent and crosslinking treatment by irradiation with ionizing radiation as described above.

[0112] On the surface of the protective layer on the adhesive layer side, if necessary, an easy-adhesion treatment may be performed. This can improve the adhesion with the adhesive layer. Also, when the protective layer is multilayered, on the surface of the polyolefin resin film opposite to the adhesive layer side, if necessary, an easy-adhesion treatment may be performed. This can improve the adhesion between the polyolefin resin film and the surface film or the primer film. Examples of the easy-adhesion treatment include corona discharge treatment, plasma treatment, and ozone treatment.

[0113] (2) Adhesive layer The adhesive layer in this embodiment is a member for attaching the protective film to the blade of a wind power generation device.

[0114] The adhesive layer is not particularly limited as long as it can attach the protective film to the blade, and is appropriately selected according to the material of the blade, etc. General adhesives can be used for the adhesive layer. For example, ultraviolet curable adhesives, two-component curable adhesives, and pressure-sensitive adhesives can be mentioned. Ultraviolet curable adhesives and two-component curable adhesives can enhance the adhesive force. Also, pressure-sensitive adhesives have good workability.

[0115] Examples of the pressure-sensitive adhesive include acrylic adhesives, urethane adhesives, and silicone adhesives. Among them, acrylic adhesives are preferred. Acrylic adhesives have good transparency, weather resistance, heat resistance, etc.

[0116] The thickness of the adhesive layer is not particularly limited as long as the protective film and the blade can be adhered, and is appropriately selected according to the application. The thickness of the adhesive layer is, for example, 25 μm or more, and it may be 25 μm or more, or may be 30 μm or more. Also, the thickness of the adhesive layer is, for example, 120 μm or less, and it may be 90 μm or less, or may be 80 μm or less. That is, the thickness of the adhesive layer is, for example, 25 μm or more and 120 μm or less, and it may be 25 μm or more and 90 μm or less, or may be 30 μm or more and 80 μm or less.

[0117] (3) Other configurations The protective film in this embodiment may have other configurations according to the application.

[0118] The protective film in this embodiment may have a separator on the surface of the adhesive layer opposite to the protective layer.

[0119] (4) Shape of the protective film The protective film adhered to the blade is preferably arranged such that the thickness of the protective film arranged on the rotation center side of the blade is thinner than the thickness of the protective film arranged on the side opposite to the rotation center of the blade.

[0120] The wind power generation device generates electricity by the rotation of the blade. When the blade is rotating, the speed on the side opposite to the rotation center of the blade, that is, the tip side, becomes extremely faster than the speed on the rotation center side. That is, the tip is more affected by the impact of birds, insects, flying objects, etc. Therefore, by increasing the thickness of the protective film on the tip side and decreasing the thickness of the protective film on the center side, the cost can be reduced and the protection effect of the blade can be improved.

[0121] Here, the types of the thickness of the protective film used are not particularly limited as long as there are multiple types. For example, two types may be used. Also, a film with continuously changed thickness may be used.

[0122] In this embodiment, the lower limit value of the difference between the thickness of the protective film used on the tip side and the thickness of the protective film used on the center side is preferably 1 μm or more, particularly preferably 10 μm or more, and most preferably 30 μm or more. On the other hand, the upper limit value is preferably 1000 μm or less, particularly preferably 900 μm or less, and most preferably 800 μm or less.

[0123] (5) Physical properties of the protective film a) Adhesive force In the protective film according to this embodiment, the adhesive force to the SUS plate is preferably, for example, 3 N / 10 mm or more, may be 7 N / 10 mm or more, and may be 10 N / 10 mm or more. By having the adhesive force within the above range, the durability can be improved. On the other hand, the upper limit of the adhesive force to the SUS plate is not particularly limited, but is preferably, for example, 30 N / 10 mm or less, may be 25 N / 10 mm or less, and may be 20 N / 10 mm or less. If the adhesive force is too large, the workability during the replacement of the protective film may deteriorate. Specifically, the adhesive force to the SUS plate is preferably 3 N / 10 mm or more and 30 N / 10 mm or less, may be 7 N / 10 mm or more and 25 N / 10 mm or less, and may be 10 N / 10 mm or more and 20 N / 10 mm or less.

[0124] The adhesive force to the SUS plate is measured in accordance with Method 6 of JIS Z0237:2009. The specific measurement conditions are shown below. As the tensile testing machine, for example, "Tensilon RTF1150" manufactured by A&D Company is used. As the SUS plate, a SUS304 steel plate with a BA surface finish is used.

[0125] <Measurement Conditions> · Tape width: 10 mm · Peel rate: 300 mm / min · Peel angle: 90 degrees · Test conditions: 23°C, 50% RH · Number of tests: Measurement is performed on 3 test pieces, and the arithmetic mean value is adopted.

[0126] In the protective film according to this embodiment, the adhesion to the fluororesin layer is preferably, for example, 2.5 N / 10 mm or more, may be 4 N / 10 mm or more, and may be 5 N / 10 mm or more. By the adhesion being within the above range, the durability can be improved. On the other hand, the upper limit of the adhesion to the fluororesin layer is not particularly limited, but is preferably, for example, 30 N / 10 mm or less, may be 25 N / 10 mm or less, and may be 20 N / 10 mm or less. If the adhesion is too large, the workability at the time of replacing the protective film may deteriorate. Specifically, the adhesion to the fluororesin layer is preferably 2.5 N / 10 mm or more and 30 N / 10 mm or less, may be 4 N / 10 mm or more and 25 N / 10 mm or less, and may be 5 N / 10 mm or more and 20 N / 10 mm or less.

[0127] The adhesion to the fluororesin-based resin layer is measured in accordance with Method 6 of JIS Z0237:2009. The specific measurement conditions are the same as those for the measurement of the adhesion to the above SUS plate. As the tensile testing machine, for example, "Tensilon RTF1150" manufactured by A&D Company is used. As the test plate, a test plate produced by the following method is used instead of the SUS plate. On one surface of the SUS substrate, a fluororesin paint ("Wind Hullo Topcoat F" manufactured by Nippon Special Paint Co., Ltd.) is applied by the roller method to form a fluororesin layer with a thickness of 100 μm to 150 μm, and this is used as the test plate.

[0128] Also, in the protective film according to this embodiment, the adhesion (N / 10 mm) to the above fluororesin layer is preferably equal to or greater than the tensile load (N) at 10% elongation of the protective layer. The durability can be improved.

[0129] The tensile load at 10% elongation of the protective layer is measured in accordance with ISO 527-3:2018 using a tensile testing machine. The measurement conditions are the same as those for the measurement of the above tensile modulus of elasticity. As the tensile testing machine, for example, "Tensilon RTF1150" manufactured by A&D Company is used.

[0130] b) Total light transmittance In this embodiment, the total light transmittance of the protective film is preferably, for example, 60% or more, more preferably 65% or more, and even more preferably 70% or more. If the total light transmittance is within the above range, the transparency is good. Therefore, since the surface of the blade can be visually confirmed through the protective film, the replacement timing of the protective film can be easily determined. The total light transmittance is measured in accordance with ISO 13468-1:1996.

[0131] c) Erosion depth In this embodiment, the erosion depth from the surface on the protective layer side of the protective film when the amount of projected particles is 40 g, obtained by the micro slurry jet erosion (MSE) test, is preferably, for example, 20 μm or less, may be 15 μm or less, and may be 12 μm or less. If the erosion depth is within the above range, the durability can be improved. The lower limit of the erosion depth is not particularly limited.

[0132] The erosion depth is a value obtained by the micro slurry jet erosion (MSE) test. In the MSE test, a certain amount of particles is projected onto the same point on the sample surface, and the operation of measuring the erosion depth is repeated to obtain the relationship between the amount of projected particles and the erosion depth.

[0133] The erosion depth is measured using the MSE test apparatus "MSE-A" manufactured by Parmesan. The measurement conditions are shown below. Using the surface on the protective layer side of the protective film as the sample surface, measure at 3 locations and use the arithmetic mean value.

[0134] <Measurement conditions> · Particles: Angular alumina (average particle diameter 1.2 μm) · Projected particle velocity: 360 km / hour · Test conditions: 25°C, 50% RH

[0135] d) Thickness uniformity In this embodiment, it is preferable that the thickness of the protective film is uniform. In the protective film, if there is an extremely thin portion, the protective film may stretch starting from that portion, and there may be a difference in durability within the plane of the protective film. Specifically, when the maximum value of the thickness of the protective film is set to 100%, the minimum value of the thickness of the protective film is preferably 80% or more, and more preferably 90% or more.

[0136] The thickness of the protective film is measured with a contact thickness gauge in accordance with JIS K7130:1999. The thickness of the protective film is measured at a plurality of locations in each of the longitudinal and transverse directions. For example, in the case of a protective film with a size of 30 cm in length and 20 cm in width, the thickness of the protective film is measured at 10 locations at 3 cm intervals in the longitudinal direction and at 10 locations at 2 cm intervals in the transverse direction. As the contact thickness gauge, for example, "ID-C112X" manufactured by Mitutoyo Corporation is used.

[0137] 2. Blade body Regarding the structure, material, etc. of the blade body, since they are the same as those of a general blade, the description here is omitted.

[0138] A-2. Second embodiment The blade of the wind power generation device of this embodiment includes a blade body, a protective film for the blade having a protective layer adhered to the surface of the blade body and an adhesive layer disposed on one surface of the protective layer, and the blade of the wind power generation device has an opposing portion where the end edges of the two protective films for the blade are adhered so as to face each other, and a protective film for preventing gaps is disposed in the opposing portion so as to overlap the end edges of the two protective films for the blade.

[0139] FIG. 5 is a schematic cross-sectional view illustrating the blade in the present embodiment. As shown in FIG. 5, the protective film 10 is adhered to the surface of the blade body 23 so as to form an opposing portion T where the end sides of the adjacent protective films 10, 10 face each other. A gap-preventing protective film 12 is adhered to the surface of the opposing portion T on the side opposite to the blade body 23.

[0140] In the present embodiment, as described above, since the gap-preventing protective film is adhered to the opposing portion, even if shrinkage over time occurs in the protective film 10 due to stretching and adhesion during the application of the protective film, and a gap is formed between the adjacent protective films 10, the blade body is not exposed because the gap-preventing protective film is adhered. Therefore, even if there are cracks or the like in the blade body 23, moisture does not enter from the gap, so deterioration of the blade body can be prevented.

[0141] Hereinafter, the blade of the present embodiment will be described separately for the gap-preventing protective film, the protective film, and the blade body.

[0142] 1. Gap-preventing protective film The shape of the gap-preventing protective film used in the present embodiment is not particularly limited as long as it can cover the opposing portion where the end sides of the adjacent protective films face each other.

[0143] The lower limit value of the width of the gap-preventing protective film is preferably, for example, 1 cm or more, particularly preferably 3 cm or more, and most preferably 5 cm or more. On the other hand, the upper limit value is preferably, for example, 100 cm or less, particularly preferably 50 cm or less, and most preferably 30 cm or less.

[0144] Although the thickness of the above-described gap-preventing protective film is not particularly limited, from the viewpoint of workability and the like, it is preferably thinner than the protective film. As a specific lower limit value of the thickness, it is preferably 5 μm or more, particularly preferably 10 μm or more, and most preferably 15 μm or more. On the other hand, as an upper limit value, it is preferably 900 μm or less, particularly preferably 800 μm or less, and most preferably 700 μm or less.

[0145] Regarding other points of the gap-preventing protective film used in this embodiment, since they are the same as those of the "protective film" described later, the description here is omitted.

[0146] 2. Protective Film Since the details of the protective film in this embodiment are the same as those described in "A. Blade of Wind Power Generation Device", "A-1. First Embodiment", and "1. Protective Film", the description here is omitted.

[0147] 3. Blade Body Since the structure, material, etc. of the blade body are the same as those of a general blade, the description here is omitted.

[0148] A-3. Third Embodiment The blade of the wind power generation device in this embodiment has a blade body, a protective layer adhered to the surface of the blade body, and an adhesive layer disposed on one surface of the protective layer, and a protective film for the blade, and an edge portion overlapping portion is formed by adhering the protective film for the blade and at least one layer of overlapping film so as to overlap at the edge portion of the blade body of the wind power generation device.

[0149] FIG. 1(b) is a schematic cross-sectional view illustrating the blade in this embodiment. As shown in FIG. 1(b), at the edge portion 21, an edge portion overlapping portion W1 is formed in which the overlapping film 14 for the overlapping portion is disposed so as to overlap on the surface of the protective film 10.

[0150] By having the blade of the wind power generation device of this embodiment configured as described above, even after a lapse of time, the edge portion W1 is provided at the edge portion 21 that is most affected by collisions with birds, insects, flying objects, etc., so that the blade can be sufficiently protected.

[0151] The edge portion overlapping portion W1 in this embodiment is an area that covers the edge portion of the blade body and is an area where a protective film and at least one layer of overlapping film are arranged.

[0152] As shown in FIG. 1(b) above, the edge portion overlapping portion W1 may be configured by overlapping the overlapping film on the protective film, or may be configured such that one end side of the protective film overlaps the opposing end side of the protective film for another adjacent blade as in the first embodiment. In this case, the overlapping film becomes the protective film for the blade.

[0153] As the lower limit value of the width of the edge portion overlapping portion W1, it is preferably, for example, 1 cm or more, particularly preferably 5 cm or more, and most preferably 10 cm or more. On the other hand, as the upper limit value, it is preferably, for example, 100 cm or less, particularly preferably 50 cm or less, and most preferably 30 cm or less.

[0154] The overlapping film may use the same film as the protective film or may use a different film.

[0155] 1. Protective film The details of the protective film in this embodiment are the same as those described in "A. Blade of Wind Power Generation Device", "A-1. First Embodiment", and "1. Protective Film", so the description here is omitted.

[0156] 2. Blade body Since the structure and material of the blade body are the same as those of a general blade, the description here is omitted.

[0157] B. Other Embodiments of the Blade of the Wind Power Generation Device Another embodiment of the blade of the wind power generation device in the present disclosure includes a blade main body, a protective film for the blade having a protective layer adhered to the surface of the blade main body and an adhesive layer disposed on one surface of the protective layer, and the protective film for the blade is adhered at least to the edge portion of the blade of the wind power generation device, and the thickness of the protective film disposed on the rotation center side of the blade of the wind power generation device is thinner than the thickness of the protective film disposed on the side opposite to the rotation center of the blade of the wind power generation device.

[0158] FIG. 6 illustrates the blade of the present embodiment. In the blade 20 shown in FIG. 6, a protective film 10 is disposed on one surface of the blade main body 23, and the thickness of the protective film 10 is configured to be thinner as it approaches the rotation center side of the blade, which is the C side of the arrow.

[0159] The wind power generation device generates electricity by the rotation of the blade. When the blade is rotating, the speed on the side opposite to the rotation center of the blade, that is, the tip side, is extremely faster than the speed on the rotation center side. That is, the tip portion is more likely to be affected by collisions with birds, insects, flying objects, etc.

[0160] When a protective film with a uniform thickness is adhered to such a blade, damage to the protective film may occur at the tip portion, and deterioration of the blade may occur. On the other hand, when the thickness is set according to the situation at the tip portion, the weight of the film to be used increases and the cost rises. At the same time, since a thick protective film is also disposed on the center side of the blade, the workability deteriorates.

[0161] In the present embodiment, in view of the above circumstances, by increasing the thickness of the protective film on the tip side and decreasing the thickness of the protective film on the center side, the cost can be reduced, the protection effect of the blade can be improved, and furthermore, the workability can also be improved.

[0162] Here, the types of the thickness of the protective film used are not particularly limited as long as there are a plurality of types. For example, there may be two types, or as shown in FIG. 6, there may be three types. Also, those with continuously changed thickness may be used.

[0163] In this embodiment, the lower limit value of the difference between the thickness of the protective film used on the tip side and the thickness of the protective film used on the center side is preferably 1 μm or more, particularly preferably 10 μm or more, and most preferably 50 μm or more. On the other hand, the upper limit value is preferably 1000 μm or less, particularly preferably 900 μm or less, and most preferably 800 μm or less.

[0164] 1. Protective Film Since the details of the protective film in this embodiment are the same as those described in "A. Blade of Wind Power Generation Device", "A-1. First Embodiment", and "1. Protective Film", the description here is omitted.

[0165] 2. Blade Body Regarding the structure, material, etc. of the blade body, since they are the same as those of a general blade, the description here is omitted.

[0166] C. Wind Power Generation Device The wind power generation device in the present disclosure includes the above-described blade.

[0167] FIG. 7 is a schematic diagram showing an example of a wind power generation device in the present disclosure. As shown in FIG. 7, the wind power generation device 30 includes a rotor 32 including blades 20 and a hub 31 that supports the blades 20, a nacelle 33, and a tower 34 that supports the rotor 32 and the nacelle 33. Although not shown, the nacelle 33 stores a main shaft connected to the hub 31 and rotating together with the hub 31, a speed increaser connected to the main shaft and increasing the rotational speed, and a generator that rotates a rotor at a rotational speed increased by the speed increaser to perform power generation operation. In FIG. 7, as the blades 20, the blades shown in the above-described first embodiment, second embodiment, third embodiment, and other embodiments are used.

[0168] In the present disclosure, by having the above-described blades, an effect of suppressing damage to the blades over a long period of time can be achieved.

[0169] The members constituting the wind power generation device are the same as those of a general wind power generation device, and thus the description here is omitted.

[0170] D. Method for Applying Protective Film for Blades In the present disclosure, there is provided a method for applying a protective film for blades to the blades of a wind power generation device, the method having an application step of applying the protective film for blades to the above-described blades, and by the application step, the blades shown in the above-described first embodiment, second embodiment, third embodiment, and other embodiments can be obtained.

[0171] The application step of applying the protective film for blades is performed in the same manner as in the prior art, and thus the description here is omitted.

[0172] E. Protective Film for Preventing Gap The protective film for preventing gap in the present disclosure is a protective film for preventing gap used to obtain the blades of the wind power generation device in the "second embodiment" of the above-mentioned "A. Blades of Wind Power Generation Device", and the width of the protective film for preventing gap is 1 cm or more and 100 cm or less.

[0173] Details of the above gap-preventing protective film are the same as those described in "A. Wind turbine blades", "A-2. Second embodiment", and "1. Gap-preventing protective film", so description here will be omitted.

[0174] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included in the technical scope of the present disclosure.

[0175] The present disclosure provides the following inventions. [1] A blade body; a blade protection film having a protective layer attached to a surface of the blade body and an adhesive layer disposed on one side of the protective layer, The blade of a wind power generation device, wherein at least two of the above-mentioned blade protective films are attached so as to overlap each other. [2] The blade of a wind power generation device described in [1], wherein the blade protective film is attached so that one end edge has an end edge overlapping portion that overlaps with an opposing end edge of another adjacent blade protective film. [3] The blade of a wind power generation device described in [2], wherein the end side overlap portion is arranged in a direction intersecting with the edge portion of the blade of the wind power generation device. [4] The blade of a wind power generation device described in [3], wherein the thickness of the protective film arranged on the side of the rotation center of the blade of the wind power generation device is thinner than the thickness of the protective film arranged on the opposite side to the rotation center of the blade of the wind power generation device. [5] It has an opposing portion where the edge sides of the two blade protection films are adhered so as to face each other, and a gap prevention protection film adhered so as to overlap the edge sides of the two blade protection films is disposed in the opposing portion. The blade of the wind power generation device according to [1]. [6] An edge overlapping portion is formed at the edge portion of the blade main body of the wind power generation device, where the blade protection film and at least one layer of overlapping film are adhered so as to overlap. The blade of the wind power generation device according to [1]. [7] The blade main body, A blade of a wind power generation device having a blade protection film adhered to the surface of the blade main body, the blade protection film having a protection layer and an adhesive layer disposed on one surface of the protection layer. The blade protection film is adhered at least to the edge portion of the blade of the wind power generation device. The thickness of the protection film disposed on the rotation center side of the blade of the wind power generation device is thinner than the thickness of the protection film disposed on the side opposite to the rotation center of the blade of the wind power generation device. The blade of the wind power generation device. [8] The protection layer contains a polyolefin resin. The blade of the wind power generation device according to any one of [1] to [7]. [9] A wind power generation device comprising the blade of the wind power generation device according to any one of [1] to [8].

[10] A method for applying a blade protection film to a blade of a wind power generation device, which comprises an application step of applying the blade protection film to the blade, and by the application step, obtaining the blade of the wind power generation device according to any one of [1] to [8]. A method for applying a blade protection film. The method for applying a blade protection film according to [1] to [8].

[11] A gap prevention protection film used to obtain the blade of the wind power generation device according to [5]. A protection film for preventing gaps, wherein the width of the protection film for preventing gaps is 1 cm or more and 100 cm or less.

Explanation of symbols

[0176] 1 … Protection layer 2 … Adhesive layer 10 … Protection film 20 … Blade 30 … Wind power generation device

Claims

1. A blade body, A blade protection film having a protective layer adhered to the surface of the blade body and an adhesive layer disposed on one surface of the protective layer, and The blade of a wind power generation device having the blade protection film, wherein at least two sheets are adhered so as to overlap.

2. The blade of the wind power generation device according to claim 1, wherein the blade protection film is adhered so as to have an edge overlapping portion where one edge overlaps the opposing edge of another blade protection film adjacent thereto.

3. The blade of the wind power generation device according to claim 2, wherein the edge overlapping portion is disposed in a direction intersecting the edge portion of the blade of the wind power generation device.

4. The blade of the wind power generation device according to claim 3, wherein the thickness of the protective film disposed on the rotation center side of the blade of the wind power generation device is thinner than the thickness of the protective film disposed on the side opposite to the rotation center of the blade of the wind power generation device.

5. The blade of the wind power generation device according to claim 1, having an opposing portion where the edges of the two blade protection films are adhered so as to face each other, and a gap prevention protective film adhered so as to overlap the edges of the two blade protection films is disposed in the opposing portion.

6. The blade of the wind power generation device according to claim 1, wherein an edge overlapping portion is formed at the edge portion of the blade body of the wind power generation device by adhering the blade protection film and at least one layer of overlapping film so as to overlap.

7. A blade body, A blade protection film having a protective layer adhered to the surface of the blade body and an adhesive layer disposed on one surface of the protective layer, and The blade protection film is adhered at least to the edge portion of the blade of the wind power generation device, and The blade of a wind power generation device, wherein the thickness of the protective film disposed on the rotation center side of the blade of the wind power generation device is thinner than the thickness of the protective film disposed on the side opposite to the rotation center of the blade of the wind power generation device.

8. The blade of the wind power generation device according to any one of claims 1 to 7, wherein the protective layer contains a polyolefin resin.

9. A wind power generation device comprising a blade of the wind power generation device according to any one of claims 1 to 7.

10. A method for applying a protective film for a blade, which applies the protective film for the blade to the blade of the wind power generation device, comprising: a film application step of applying the protective film for the blade to the blade, and obtaining the blade of the wind power generation device according to any one of claims 1 to 7 by the film application step. A method for applying a protective film for a blade.

11. A protective film for preventing gaps, which is used to obtain the blade of the wind power generation device according to claim 5, comprising: a protective film for preventing gaps, wherein the width of the protective film for preventing gaps is 1 cm or more and 100 cm or less.

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