Structures and gas resistance reduction structures

Abstract

A structure in which a resin component containing polyvinyl chloride resin and the resin layer on top thereof exhibit good adhesion. [Solution] The present invention provides a structure comprising a resin member containing polyvinyl chloride resin and a resin layer disposed on one surface of the resin member in contact with the resin member, wherein the resin layer contains a polymer having a first constituent unit represented by formula (1). TIFF2026070098000013.tif6871

Description

Technical Field

[0001] The present disclosure relates to a structure having a resin member containing a vinyl chloride resin.

Background Art

[0002] Vinyl chloride resin is one of the general-purpose plastics and is used in various products. However, resin members containing vinyl chloride resin have a problem of low adhesion to a coating film. This is because a plasticizer is often added to the vinyl chloride resin, and the migration of the plasticizer is one of the factors causing the decrease in adhesion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure has been made in view of the above problems, and an object thereof is to provide a structure in which the adhesion between a resin member containing a vinyl chloride resin and a resin layer disposed on the resin member is good.

Means for Solving the Problems

[0005] The inventors of the present disclosure were considering forming a resin layer containing a cured product of a curable resin composition on a resin member containing a vinyl chloride resin, and found that the adhesion is improved by using a predetermined monomer in the curable resin composition. The present disclosure is based on such new findings.

[0006] One embodiment of the present disclosure provides a structure comprising a resin member containing a vinyl chloride resin and a resin layer disposed on one surface of the resin member in contact with the resin member, wherein the resin layer contains a polymer having a first structural unit represented by the following formula (1).

[0007] [ka] (In formula (1) above, A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent.

[0008] Another embodiment of the present disclosure provides a gas resistance reducing structure comprising a resin member containing a polyvinyl chloride resin and a resin layer disposed on one surface of the resin member in contact with the resin member, wherein the gas resistance reducing structure has an uneven surface structure on the surface of the resin layer, and the resin layer contains a polymer having a first constituent unit represented by the following formula (1).

[0009] [ka] (In formula (1) above, A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent. [Effects of the Invention]

[0010] This disclosure provides the effect of improving the adhesion between a resin component containing polyvinyl chloride resin and a resin layer. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view illustrating the structure in this disclosure. [Figure 2] This is a schematic cross-sectional view illustrating an example of a gas resistance reduction structure in this disclosure. [Figure 3] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 4] This is a schematic perspective view illustrating an example of a gas resistance reduction structure in this disclosure. [Figure 5] This is a schematic diagram illustrating the gas flow in the gas resistance reduction structure described herein. [Figure 6] This is a schematic diagram illustrating the gas flow in a gas resistance reduction structure. [Figure 7] This is a schematic cross-sectional view illustrating an example of a gas resistance reduction structure in this disclosure. [Figure 8] This is a schematic perspective view illustrating an example of a gas resistance reduction structure in this disclosure. [Figure 9] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 10] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 11] This is a schematic plan view illustrating a gas resistance reduction structure in this disclosure. [Figure 12] This is a schematic cross-sectional view illustrating a first region of the gas resistance reduction structure in this disclosure. [Figure 13] This is a schematic cross-sectional view illustrating a protrusion in the first region of the gas resistance reduction structure in this disclosure. [Figure 14] This is a schematic plan view illustrating a gas resistance reduction structure in this disclosure. [Figure 15] This is a schematic side view illustrating an example of the application of the gas resistance reduction structure described herein. [Figure 16] This is a schematic diagram illustrating a method for manufacturing the film-like gas resistance reducing structure of the present disclosure. [Figure 17] This is a schematic diagram illustrating a manufacturing method for other film-like gas resistance reducing structures. [Figure 18] This is a schematic perspective view illustrating an example of a film-like gas resistance reducing structure according to the present disclosure. [Figure 19]This is a schematic perspective view illustrating other film-like gas resistance reducing structures. [Figure 20] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 21] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 22] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 23] These are schematic plan views and cross-sectional views illustrating gas resistance reduction structures in this disclosure. [Figure 24] This is a schematic cross-sectional view illustrating an example of a gas resistance reduction structure in this disclosure. [Figure 25] This is a schematic cross-sectional view illustrating an example of a gas resistance reduction structure in this disclosure. [Modes for carrying out the invention]

[0012] Embodiments of this disclosure will be described below with reference to drawings and other figures. However, this disclosure can be implemented in many different ways and should not be interpreted as being limited to the embodiments described below. In addition, the drawings may be schematically represented in terms of width, thickness, shape, etc. of each part compared to the actual form in order to make the explanation clearer, but these are merely examples and should not limit the interpretation of this disclosure. Furthermore, in this specification and each figure, elements similar to those described above with respect to previously shown figures will be denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0013] In this specification, when describing a configuration in which one member is placed on top of another member, unless otherwise specified, the terms "on top" or "below" include both cases: one in which the other member is placed directly above or below the other member so as to be in contact with it, and another in which the other member is placed above or below the other member via yet another member. Similarly, when describing a configuration in this specification in which one member is placed on the surface of another member, unless otherwise specified, the terms "on the surface" include both cases: one in which the other member is placed directly above or below the other member so as to be in contact with it, and another in which the other member is placed above or below the other member via yet another member.

[0014] Furthermore, in this specification, the terms “film,” “sheet,” and “plate” are not distinguished from each other solely on the basis of name differences. For example, “film” includes sheets and plates.

[0015] The structures and gas resistance reduction structures described herein will be explained in detail below.

[0016] A. Structure The present disclosure provides a structure comprising a resin member containing a polyvinyl chloride resin and a resin layer disposed on one surface of the resin member in contact with the resin member, wherein the resin layer contains a polymer having a first structural unit represented by the following formula (1).

[0017] [ka] (In formula (1) above, A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent.

[0018] FIG. 1 is a schematic cross-sectional view showing an example of the structure in the present disclosure. As shown in FIG. 1, the structure 1 has a resin member 2 containing vinyl chloride resin, and a resin layer 3 disposed on one surface of the resin member 2 in contact with the resin member 2. The resin layer 3 contains a polymer having a predetermined first constitutional unit.

[0019] In the present disclosure, by the resin layer containing a polymer having a predetermined first constitutional unit, the adhesion between the resin member containing vinyl chloride resin and the resin layer can be improved. The reason for this is not clear, but it is considered as follows. Generally, since the SP value of vinyl chloride resin and cyclohexanone is close, it is known that vinyl chloride resin dissolves in cyclohexanone. Also, since the SP value of vinyl chloride resin and cyclohexyl acrylate is close, it is considered that vinyl chloride resin dissolves in cyclohexyl acrylate. For reference, the SP value of vinyl chloride resin is 9.3, the SP value of cyclohexanone is 9.9, and the SP value of cyclohexyl acrylate is 9.26. In the present disclosure, the resin layer contains a polymer having a first constitutional unit represented by the above formula (1), and the first constitutional unit is derived from a monomer represented by the following formula (2).

[0020] [Chemical formula] (In the above formula (2), A 1 represents a polymerizable functional group, X represents a direct bond or a divalent linking group, and R 1 ~R 10 each independently represents a hydrogen atom or a substituent.)

[0021] In this disclosure, the resin layer is formed by applying a curable resin composition containing the above monomer onto a resin member and curing it. The above monomer typically has low viscosity. Furthermore, the above monomer contains cyclohexyl acrylate, and even if the above monomer is a monomer other than cyclohexyl acrylate, its structure is similar to that of cyclohexyl acrylate. In addition, the above monomer is structurally similar to cyclohexanone. Therefore, the above monomer has good affinity with vinyl chloride resin, and it is considered that the above monomer easily penetrates the resin member when the curable resin composition is applied onto the resin member. Furthermore, when the curable resin composition is cured, it is considered that the above monomer that has penetrated the resin member polymerizes near the interface between the resin member and the resin layer. Therefore, it is presumed that the adhesion between the resin member and the resin layer is improved.

[0022] The following describes the various components of the structure in this disclosure.

[0023] 1. Resin layer The resin layer in this disclosure contains a polymer that is disposed on one surface of the resin member in contact with the resin member and has a first structural unit represented by formula (1) above.

[0024] (1) Material of the resin layer (a) polymer The polymer contained in the resin layer in this disclosure has a first structural unit represented by the following formula (1).

[0025] [ka]

[0026] In formula (1) above, A represents a structure derived from a polymerizable functional group. Examples of polymerizable functional groups include (meth)acryloyloxy groups, epoxy groups, oxetanyl groups, vinyl groups, vinyl ether groups, etc. Among these, A is preferably a (meth)acryloyloxy group.

[0027] In this specification, (meth)acryloyl means acryloyl and methacryloyl respectively. (meth)acrylic means acrylic and methacrylic respectively. (meth)acrylate means acrylate and methacrylate respectively.

[0028] In formula (1) above, X represents a direct bond or a divalent linking group. The divalent linking group is not particularly limited and includes, for example, an atom or group of atoms containing at least one of a carbon atom or an oxygen atom. Among these, X is preferably a direct bond.

[0029] In the above equation (1), R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent. A substituent is an atom or group of atoms other than a hydrogen atom that can be replaced by a hydrogen atom. Examples of substituents include -YR 20 Examples of atomic groups represented by are shown. Y is either a direct bond or a divalent linking group. The divalent linking group is not particularly limited and includes, for example, an atom or atomic group containing at least one of a carbon atom or an oxygen atom. Among these, Y is preferably a direct bond. 20 This is not particularly limited to any atom or group of atoms other than hydrogen atoms that can be replaced by a hydrogen atom. 20 Examples include alkyl groups, allyl groups, phenyl groups, and alkoxy groups. Among these, R 20 The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a straight chain or a branched chain.

[0030] The first constituent unit is preferably a constituent unit represented by the following formula (3).

[0031] [ka] (In the above formula (3), R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent, and R 11 (This represents a hydrogen atom or a methyl group.)

[0032] Specific examples of monomers having a cyclohexane ring that correspond to the first structural unit include cyclohexyl (meth)acrylate and alkylcyclohexyl (meth)acrylate. For example, 4-tert-butylcyclohexyl (meth)acrylate, 1,4-cyclohexanedimethanol monoacrylate, 3,3,5-trimethylcyclohexyl acrylate, 4-methylcyclohexyl (meth)acrylate, 2,4-dimethylcyclohexyl (meth)acrylate, 2,4,6-trimethylcyclohexyl (meth)acrylate, 2,4-dimethylcyclohexylmethyl (meth)acrylate, 2,4,6-trimethylcyclohexylmethyl (meth)acrylate, and cyclohexyl Silmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, cyclohexylpropyl (meth)acrylate, cyclohexylbutyl (meth)acrylate, 4-methylcyclohexylmethyl (meth)acrylate, 4-ethylcyclohexylmethyl (meth)acrylate, 4-propylcyclohexylmethyl (meth)acrylate, 4-butylcyclohexylmethyl (meth)acrylate, 4-methoxycyclohexylmethyl (meth)acrylate, 4-acetoxymethylcyclohexyl 3-methyl(meth)acrylate, 3-methylcyclohexylmethyl(meth)acrylate, 3-ethylcyclohexylmethyl(meth)acrylate, 3-propylcyclohexylmethyl(meth)acrylate, 3-butylcyclohexylmethyl(meth)acrylate, 3-methoxycyclohexylmethyl(meth)acrylate, 3-acetoxymethylcyclohexylmethyl(meth)acrylate, 3-hydroxymethylcyclohexylmethyl(meth)acrylate, 4-methylcyclohexylethyl(meth)acrylate ) Acrylate, 4-ethylcyclohexylethyl (meth)acrylate, 4-propylcyclohexylethyl (meth)acrylate, 4-butylcyclohexylethyl (meth)acrylate, 4-methoxycyclohexylethyl (meth)acrylate, 4-acetoxymethylcyclohexylethyl (meth)acrylate, 4-hydroxymethylcyclohexylethyl (meth)acrylate, 3-methylcyclohexylethyl (meth)acrylate, 3-ethylcyclohexylethyl (meth)acrylate,3-Propylcyclohexylethyl (meth)acrylate, 3-Butylcyclohexylethyl (meth)acrylate, 3-Methoxycyclohexylethyl (meth)acrylate, 3-Acetoxymethylcyclohexylethyl (meth)acrylate, 3-Hydroxymethylcyclohexylethyl (meth)acrylate, 4-Methylcyclohexylpropyl (meth)acrylate, 4-Ethylcyclohexylpropyl (meth)acrylate, 4-Methoxycyclohexylpropyl (meth)acrylate, 4-Acetoxymethylcyclohexylpropyl (meth)acrylate, 4-Hydroxymethylcyclohexylpropyl (meth)acrylate, 3-Methylcyclohexylpropyl (meth)acrylate, 3-Ethylcyclohexylpropyl (meth)acrylate, 3-Methoxycyclohexylpropyl (meth)acrylate, 3-Acetoxymethylcyclohexylpropyl (meth)acrylate, 3-Hydroxymethylcyclohexylpropyl ( Examples include meth)acrylate, 4-methylcyclohexylbutyl (meth)acrylate, 4-ethylcyclohexylbutyl (meth)acrylate, 4-methoxycyclohexylbutyl (meth)acrylate, 4-acetoxymethylcyclohexylbutyl (meth)acrylate, 4-hydroxymethylcyclohexylbutyl (meth)acrylate, 3-methylcyclohexylbutyl (meth)acrylate, 3-ethylcyclohexylbutyl (meth)acrylate, 3-methoxycyclohexylbutyl (meth)acrylate, 3-acetoxymethylcyclohexylbutyl (meth)acrylate, 3-hydroxymethylcyclohexylbutyl (meth)acrylate, 2-methyl-1-cyclohexylmethyl (meth)acrylate, 2,3-dimethyl-1-cyclohexylmethyl (meth)acrylate, 2,4-dimethyl-1-cyclohexylmethyl (meth)acrylate, and 2,6-dimethyl-1-cyclohexylmethyl (meth)acrylate. These may be used individually or in combination of two or more. Among them, cyclohexyl (meth)acrylate and 4-tert-butylcyclohexyl (meth)acrylate are preferred.

[0033] The polymer contained in the resin layer preferably has other structural units in addition to the first structural unit described above, including structures derived from polymerizable functional groups. The compounds corresponding to the other structural units are not particularly limited, and various polyfunctional monomers and polyfunctional oligomers can be used. The polymerizable functional groups in the other structural units are the same as those in the first structural unit described above. In particular, the compounds corresponding to the other structural units are preferably polyfunctional acrylate monomers and polyfunctional acrylate oligomers. These may be used individually or in combination of two or more.

[0034] Furthermore, it is preferable that the polymer contained in the resin layer further comprises a second structural unit including a structure derived from polymerizable functional groups and a urethane bond. The introduction of the second structural unit including the urethane bond imparts toughness, flexibility, and extensibility to the resin layer. Therefore, as will be described later, when the resin component is a resin film, it is possible to suppress the occurrence of cracks and peeling in the resin layer when the resin component is stretched. Thus, when applying the structure to the surface of an object, it is possible to suppress the occurrence of cracks and peeling in the resin layer when the resin component is stretched to conform to the surface of the object. This is particularly useful when applying the structure to the surface of an object having a curved surface.

[0035] Various urethane monomers and urethane oligomers can be used as compounds corresponding to the second structural unit. The polymerizable functional group in the second structural unit is the same as that in the first structural unit. In particular, the compound corresponding to the second structural unit is preferably a urethane acrylate.

[0036] Furthermore, the second structural unit contains a urethane bond and therefore includes a structure derived from the polyol. Examples of polyols include polycarbonate polyol, polyester polyol, and polyether polyol. Among these, polycarbonate polyol is preferred. That is, it is preferable that the second structural unit includes a structure derived from the polycarbonate polyol. This can improve the weather resistance of the resin layer. The polyol may be used alone or in combination of two or more types.

[0037] Furthermore, the second structural unit contains a urethane bond and therefore includes a structure derived from an isocyanate. Examples of isocyanates include aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates. Among these, aliphatic isocyanates and alicyclic isocyanates are preferred, and alicyclic isocyanates are more preferred. In other words, it is preferable that the second structural unit includes a structure derived from an aliphatic isocyanate or an alicyclic isocyanate. This can improve the weather resistance of the resin layer. Examples of alicyclic isocyanates include isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. The isocyanate may be used alone or in combination of two or more types.

[0038] The content of the first structural unit in the polymer is, for example, 20% by mass or more and 80% by mass or less, and may be 30% by mass or more and 70% by mass or less, or 40% by mass or more and 60% by mass or less. If the content of the first structural unit is within the above range, the adhesion between the resin member and the resin layer can be further improved.

[0039] When a polymer has a first structural unit and a second structural unit, the content of the second structural unit in the polymer is, for example, 20% by mass or more and 80% by mass or less, and may also be 30% by mass or more and 70% by mass or less, or 40% by mass or more and 60% by mass or less. When the resin member is a resin film, if the content of the second structural unit is within the above range, cracks and peeling of the resin layer when the resin member is stretched can be further suppressed.

[0040] It is confirmed by FT-IR (Fourier Transform Infrared Spectroscopy) and TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) that the polymer has the first structural unit. The measurement conditions are shown below. As the Fourier Transform Infrared Spectrophotometer, for example, "Nicolet6700" manufactured by Thermo Fisher Scientific can be used. As the Time-of-Flight Secondary Ion Mass Analyzer, for example, "TOF.SIM5" manufactured by ION-TOF can be used.

[0041] <FT-IR Measurement Conditions> · Measurement method: Microscopic ATR method (Ge) · Measurement depth region: Surface to 1 μm · Resolution: 4 cm -1 · Number of integrations: 64 times

[0042] <TOF-SIMS Measurement Conditions> · Measurement conditions: Irradiated primary ion 209Bi3+ + · Measurement range: Approximately 250 μm × 250 μm · Secondary ions to be detected: Positive / Negative · Information depth: Approximately 1 nm · Detection sensitivity: Dozens of ppm to hundreds of ppm [[ID="29"]]

[0043] In FT-IR, by using the database of IR spectra and comparing the similarity between the obtained IR spectrum and the database of IR spectra, the first structural unit is estimated. Specifically, in the IR spectrum, when peaks derived from the cyclohexane ring and peaks derived from the above-mentioned polymerizable functional group are present, it is considered that the polymer has the first structural unit. The peak derived from the cyclohexane ring appears around 1450 cm -1 When the above-mentioned polymerizable functional group is an acryloyloxy group, the peak derived from the acryloyloxy group is around 1700 cm -1 (C=O stretching of the carbonyl group), around 1100 cm -1 to 1300 cm -1 (C-O stretching), 1600 cm -1It appears in the vicinity (C=C expansion of the vinyl group). Furthermore, if the polymerizable functional group is a methacryloyloxy group, the peak originating from the methacryloyloxy group appears at 1700 cm⁻¹. -1 Nearby (C=O expansion), 1100cm -1 From 1300cm -1 Nearby (CO expansion), 1600cm -1 Nearby (C=C stretch), 2900cm -1 It appears at (CH stretching of the methyl group). Note that the above peak position may shift depending on the structure of the first constituent unit. For example, if the monomer having a cyclohexane ring corresponding to the first constituent unit is cyclohexyl acrylate, then in the IR spectrum, it appears at 2900 cm⁻¹. -1 Nearby, 1448cm -1 , 1038cm -1 , 1014cm -1 , 891cm -1 , 840cm -1 If a peak is present, it is presumed that the first structural unit originates from cyclohexyl acrylate, and the polymer is considered to have a first structural unit.

[0044] Furthermore, if the following ions are detected in TOF-SIMS, the polymer is considered to have a first constituent unit. Positive ion: C6H8O2 + , C7H9O3 + Negative ion: C4H5O2 - , C6H 11 O - , C7H7O3 -

[0045] The presence of a second structural unit in the polymer is confirmed by FT-IR (Fourier transform infrared spectroscopy) and TOF-SIMS (time-of-flight secondary ion mass spectrometry), similar to the first structural unit. In FT-IR, the IR spectrum shows a 1530 cm⁻¹ spectrum originating from the NH bond. -1 , derived from the C=O bond 1720 cm -1If the peak is present, the polymer is considered to have a second structural unit. In TOF-SIMS, if the following ions are detected, the polymer is considered to have a second structural unit. Positive ion: C3H8N + C4H 10 N + C9H 16 N + Negative ions: CN - , CNO -

[0046] Furthermore, to confirm that a polymer has a first or second constituent unit, molecular weight measurement is performed using GPC (gel permeation chromatography) to determine whether it is a monomer or a polymer. Monomers have molecular weights ranging from tens to thousands, while polymers have molecular weights in the tens of thousands; therefore, the order of magnitude of the molecular weight determines whether it is a monomer or a polymer.

[0047] The content of the first structural unit in the polymer is measured by FT-IR (Fourier transform infrared spectroscopy). The measurement conditions are the same as those used in the method for confirming that the polymer contains the first structural unit. First, using an IR spectrum database, the monomer containing a cyclohexane ring corresponding to the first structural unit is estimated by comparing the similarity between the obtained IR spectrum and the IR spectrum database. Next, standard solutions of different concentrations are prepared using the estimated monomers containing a cyclohexane ring, and FT-IR measurements are performed on the standard solutions, resulting in a reading of 10³⁸ cm⁻¹. -1 and 1014cm -1 A calibration curve is created by plotting the peak areas in the vicinity. Using this calibration curve, the 1038 cm⁻¹ of the obtained IR spectrum is calculated. -1 and 1014cm -1 The content of the first structural unit of the polymer is determined from the peak area in the vicinity.

[0048] The content of the second structural unit in the polymer is measured by FT-IR (Fourier transform infrared spectroscopy), similar to the first structural unit described above.

[0049] (b) UV absorbers The resin layer in this disclosure preferably contains an ultraviolet absorber. This can improve the weather resistance of the resin layer.

[0050] The UV absorber preferably absorbs long-wavelength ultraviolet light. The absorption wavelength peak of the UV absorber is preferably, for example, 290 nm to 364 nm, more preferably 300 nm to 350 nm, and even more preferably 310 nm to 340 nm. The UV absorber can efficiently absorb long-wavelength ultraviolet light, thereby further improving the weather resistance of the resin layer.

[0051] The absorption wavelength peak of an ultraviolet absorber is determined by the following method. First, the transmittance of the resin layer is determined as described later. Next, the cut wavelength of the resin layer is determined. The cut wavelength is the wavelength at which the transmittance is 10% or less. Then, the wavelength at which the transmittance is lowest within the cut wavelength range of the resin layer is considered to be the absorption wavelength peak of the ultraviolet absorber.

[0052] When using a curable resin composition containing a polymerization initiator in the resin layer, it is preferable that the absorption wavelength band of the ultraviolet absorber differs from that of the polymerization initiator. Specifically, it is preferable that the absorption wavelength peak of the ultraviolet absorber differs from that of the polymerization initiator. More specifically, it is preferable that the absorption wavelength peak of the ultraviolet absorber differs from the exposure wavelength required to cure the curable resin composition. By shifting the absorption wavelength band of the ultraviolet absorber from that of the polymerization initiator required to cure the curable resin composition, curing inhibition can be suppressed. In other words, by shifting the absorption wavelength band of the ultraviolet absorber from that of the exposure wavelength, curing inhibition can be suppressed.

[0053] The transmittance of the UV absorber at a wavelength of 365 nm is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more. The exposure wavelength for curing curable resin compositions is mainly the i-line (365 nm). Therefore, if the transmittance of the UV absorber at a wavelength of 365 nm falls within the above range, it can be said that the absorption wavelength band of the UV absorber is offset from the exposure wavelength.

[0054] Furthermore, the transmittance of the UV absorber at a wavelength of 405 nm is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more. In some cases, the g-line (405 nm) is used as the exposure wavelength for curing the curable resin composition. Therefore, if the transmittance of the UV absorber at a wavelength of 405 nm falls within the above range, it can be said that the absorption wavelength band of the UV absorber is shifted from the exposure wavelength.

[0055] The transmittance of the UV absorber is determined by the following method. First, the transmittance of the resin layer is determined as described later. Then, the transmittance of the resin layer is considered to be the transmittance of the UV absorber.

[0056] When the resin layer contains an ultraviolet absorber, the transmittance of the resin layer at a wavelength of 380 nm is preferably 95% or less, more preferably 80% or less, and even more preferably 70% or less. If the transmittance of the resin layer at a wavelength of 380 nm is within the above range, it can be said that the resin layer containing the ultraviolet absorber is absorbing long-wavelength ultraviolet light. Therefore, the structure can be protected from long-wavelength ultraviolet light by the resin layer. On the other hand, the transmittance of the resin layer at a wavelength of 380 nm is, for example, 40% or more. If the transmittance of the resin layer at a wavelength of 380 nm is too low, the transmission of visible light around 380 nm will be inhibited, which may cause the resin layer to take on a yellowish tint.

[0057] The transmittance of the resin layer is determined by the following method. First, the transmittance of the structure is measured using a spectrophotometer. Next, only the resin layer is removed from the structure. Methods for removing the resin layer include polishing. Then, the transmittance of the structure after the resin layer has been removed is measured using a spectrophotometer. Finally, the transmittance of the resin layer is calculated from the difference in transmittance before and after the removal of the resin layer. The spectrophotometer used conforms to JIS K7361-1:1997 (Plastics - Test methods for total light transmittance of transparent materials - Part 1: Single beam method). The transmittance of the resin layer is the arithmetic mean of three measured values.

[0058] The UV absorber is preferably one that satisfies the above characteristics, and examples include triazine-based UV absorbers, benzotriazole-based UV absorbers, and benzophenone-based UV absorbers. Among these, triazine-based UV absorbers are preferred from the viewpoint of absorption wavelength range. Furthermore, hydroxyphenyltriazine-based UV absorbers are preferred from the viewpoint of weather resistance.

[0059] The amount of ultraviolet absorber in the resin layer is, for example, 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the resin component.

[0060] When a curable resin composition containing a polymerization initiator is used in the resin layer, as described above, it is preferable that the absorption wavelength peak of the polymerization initiator differs from the absorption wavelength peak of the ultraviolet absorber. In particular, it is preferable that the polymerization initiator absorbs long-wavelength ultraviolet light, and more preferably that it absorbs long wavelengths within long-wavelength ultraviolet light. By having the absorption wavelength peak of the polymerization initiator be on the longer wavelength side than the absorption wavelength of the ultraviolet absorber, inhibition of the polymerization reaction can be suppressed. The polymerization initiator is appropriately selected from known radical polymerization initiators.

[0061] (c) Other ingredients The resin layer in this disclosure may optionally contain additives such as light stabilizers, antioxidants, plasticizers, stabilizers, lubricants, fillers, colorants, processing aids, antistatic agents, and twist-resistant agents.

[0062] (2) Other aspects of the resin layer In this disclosure, the resin layer is disposed on one surface of the resin member, in contact with the resin member. As will be described later, if the resin member is a resin film, the resin layer is disposed on one surface of the resin film. Also, if the resin member is a molded resin product, the resin layer is disposed on at least one surface of the molded resin product.

[0063] The resin layer may be arranged across the entire surface of one face of the resin member, or it may be arranged in a pattern on one face of the resin member. In particular, when the resin member is a resin film, it is preferable that the resin layer be arranged across the entire surface of one face of the resin member. When the resin layer is arranged across the entire surface of one face of the resin member, there is a concern that cracks and peeling may easily occur in the resin layer when the resin member is stretched. However, as described above, by having a polymer contained in the resin layer that has a first structural unit and a second structural unit, it is possible to suppress the occurrence of cracks and peeling in the resin layer when the resin member is stretched.

[0064] The resin layer may have a flat surface, as shown in Figure 1, or it may have an uneven surface structure, as described in "B. Gas Resistance Reduction Structure" below.

[0065] The thickness of the resin layer is set appropriately according to the form of the resin component, the surface shape of the resin layer, and the application of the structure. When the resin component is a resin film and the surface of the resin layer is flat, the thickness of the resin layer is, for example, 5 μm to 500 μm. When the resin component is a resin film and the resin layer has an uneven surface structure, the thickness of the region where the recesses of the uneven structure exist is, for example, 5 μm to 50 μm. In the above case, the height of the protrusions of the uneven structure is, for example, 1 μm to 2000 μm. If the thickness of the resin layer is within the above range, cracking and peeling of the resin layer can be suppressed.

[0066] One method for forming a resin layer is to apply a curable resin composition onto a resin member and cure it. Curing methods include irradiation with ionizing radiation such as ultraviolet light, visible light, or electron beams, and heating. Among these, ultraviolet irradiation is preferred. When the resin layer has an uneven surface structure, and the resin layer is formed using a mold as described later, the ultraviolet-curable resin composition is liquid before curing, and even if the aspect ratio of the mold's uneven shape is high, the ultraviolet resin composition can be filled into the irregularities of the mold. Furthermore, when the resin member is a resin film, and an adhesive layer is placed on the side of the resin member opposite to the resin layer, the flatness of the side of the resin member opposite to the resin layer can be maintained, allowing the structure to be smoothly attached to the substrate. In addition, high productivity and cost reduction can be achieved.

[0067] 2. Resin components The resin component in this disclosure contains polyvinyl chloride resin.

[0068] The vinyl chloride resin may be a homopolymer of vinyl chloride monomers, or a copolymer of vinyl chloride monomers and other monomers.

[0069] Other monomers copolymerizable with vinyl chloride monomer include, for example, vinyl esters, (meth)acrylic acid esters, maleic acid esters, fumaric acid esters, vinyl ethers, vinyl cyanides, olefins, dienes, vinylidene halides, vinyl halides other than vinyl chloride, and allyl phthalates. Examples of vinyl esters include vinyl acetate and vinyl propionate. Examples of (meth)acrylic acid esters include methyl acrylate, butyl acrylate, methyl methacrylate, and ethyl methacrylate. Examples of maleic acid esters include butyl maleate and diethyl maleate. Examples of fumaric acid esters include dibutyl fumarate and diethyl fumarate. Examples of vinyl ethers include vinyl methyl ether, vinyl butyl ether, and vinyl octyl ether. Examples of vinyl cyanides include acrylonitrile and methacrylonitrile. Examples of olefins include ethylene, propylene, butylene, and styrene. Examples of dienes include isoprene and butadiene. Examples of vinylidene halides include vinylidene chloride. Examples of vinyl halides include vinyl bromide. Examples of allyl phthalates include diallyl phthalate. These other monomers may be used individually or in combination of two or more.

[0070] The resin component may further contain other resins other than polyvinyl chloride resin. Examples of such other resins include acrylic resin, chlorinated polyethylene, and ethylene-vinyl acetate copolymer. When the resin component contains other resins, from the viewpoint of adhesion between the resin component and the resin layer, as well as flexibility and processability, the content of polyvinyl chloride resin in the resin component is preferably 50 parts by mass or more, and preferably 70 parts by mass or more, per 100 parts by mass of the resin component.

[0071] The resin component preferably contains a plasticizer. This disclosure is effective because the adhesion between the resin component and the resin layer tends to decrease when the resin component contains a plasticizer. Furthermore, as will be described later, the resin component is preferably a resin film, and the resin film usually contains a plasticizer. The plasticizer is appropriately selected from known plasticizers used in polyvinyl chloride resins. The plasticizer may be used alone or in combination of two or more types.

[0072] Furthermore, the resin component may contain additives such as heat stabilizers, ultraviolet absorbers, light stabilizers, flame retardants, fillers, lubricants, and colorants, as needed.

[0073] When a resin component contains an ultraviolet absorber, and ultraviolet light is irradiated from the resin component side during the formation of the resin layer, it is preferable that the absorption wavelength band of the ultraviolet absorber contained in the resin component differs from the absorption wavelength band of the polymerization initiator contained in the curable resin composition used for the resin layer. Specifically, it is preferable that the absorption wavelength peak of the ultraviolet absorber contained in the resin component differs from the absorption wavelength peak of the polymerization initiator used for the resin layer. More specifically, it is preferable that the absorption wavelength peak of the ultraviolet absorber contained in the resin component differs from the exposure wavelength for curing the curable resin composition used for the resin layer. By shifting the absorption wavelength band of the ultraviolet absorber contained in the resin component from the absorption wavelength band of the polymerization initiator for curing the curable resin composition used for the resin layer, inhibition of curing the resin layer can be suppressed. In other words, by shifting the absorption wavelength band of the ultraviolet absorber contained in the resin component from the exposure wavelength during the formation of the resin layer, inhibition of curing the resin layer can be suppressed.

[0074] When ultraviolet light is irradiated from the resin member side during the formation of the above resin layer, the transmittance of the resin member at a wavelength of 365 nm is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more. The exposure wavelength is mainly the i-line (365 nm). Therefore, if the transmittance of the resin member at a wavelength of 365 nm is within the above range, the above resin layer can be sufficiently cured. Furthermore, if the transmittance of the resin member at a wavelength of 365 nm is within the above range, it can be said that the absorption wavelength band of the ultraviolet absorber contained in the resin member is shifted from the exposure wavelength.

[0075] Furthermore, when ultraviolet light is irradiated from the resin member side during the formation of the resin layer, the transmittance of the resin member at a wavelength of 405 nm is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more. In some cases, the g-line (405 nm) may be used as the exposure wavelength. Therefore, by having the transmittance of the resin member at a wavelength of 405 nm within the above range, the resin layer can be sufficiently cured. Also, if the transmittance of the resin member at a wavelength of 405 nm is within the above range, it can be said that the absorption wavelength band of the ultraviolet absorber contained in the resin member is shifted from the exposure wavelength.

[0076] The transmittance of the resin component is measured using a spectrophotometer. When measuring the transmittance of the resin component, only the resin component is removed from the structure. Methods for removing components other than the resin component from the structure include polishing. As for the spectrophotometer, for example, a measuring instrument conforming to JIS K7361-1:1997 (Plastics - Test method for total light transmittance of transparent materials - Part 1: Single beam method) is used. Furthermore, the transmittance of the resin component is the arithmetic mean of three measured values.

[0077] The resin component may be transparent or opaque.

[0078] The form of the resin member is not particularly limited and includes, for example, a resin film and a resin molded product. Among these, a resin film is preferred. When the resin member is a resin film, a resin layer is arranged on one side of the resin film. When the resin member is a resin molded product, a resin layer is arranged on at least one side of the resin molded product.

[0079] The thickness of the resin film is not particularly limited and can be appropriately selected depending on the application. When the structure in this disclosure is used as a wrapping film or marking film for moving objects such as automobiles, trains, and aircraft, the thickness of the resin film is, for example, 80 μm to 350 μm. When the structure in this disclosure is used as a decorative material, the thickness of the resin film is, for example, 1 μm to 1000 μm, or 10 μm to 500 μm.

[0080] 3. Other layers The structures in this disclosure may have other layers besides resin members and resin layers, as needed. The other layers are selected as appropriate depending on the application of the structure.

[0081] 4.Applications Applications of the structure described in this disclosure include, for example, the gas resistance reduction structure, wrapping film, marking film, and decorative material described later. Among these, the structure described in this disclosure is preferably used in the gas resistance reduction structure described later.

[0082] B. Gas resistance reduction structure The gas resistance reducing structure in this disclosure comprises a resin member containing polyvinyl chloride resin and a resin layer disposed on one surface of the resin member in contact with the resin member, wherein the gas resistance reducing structure has an uneven surface structure on the surface of the resin layer, and the resin layer contains a polymer having a first constituent unit represented by the following formula (1).

[0083] [ka] (In formula (1) above, A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent.

[0084] Figure 2 is a schematic cross-sectional view showing an example of a gas resistance reduction structure in this disclosure. As shown in Figure 2, the gas resistance reduction structure 10 includes a resin member 2 and a resin layer 3 disposed in contact with one surface of the resin member 2. The gas resistance reduction structure 10 has an uneven surface structure 7 with convex portions 5 and concave portions 6 on the surface of the resin layer 3. The resin layer 3 also contains a polymer having a predetermined first constituent unit.

[0085] In this disclosure, similar to the structure described above, the adhesion between the resin member containing vinyl chloride resin and the resin layer can be improved by including a polymer having a predetermined first structural unit in the resin layer.

[0086] Furthermore, the gas resistance reduction structure in this disclosure can reduce gas resistance by having an uneven surface structure on the surface of the resin layer.

[0087] The following describes the various components of the gas resistance reduction structure in this disclosure.

[0088] 1. Resin layer The resin layer in this disclosure contains a polymer having a first structural unit represented by formula (1) above, which is disposed on one surface of the resin member in contact with the resin member. The gas resistance reducing structure in this disclosure has an uneven surface on the surface of the resin layer.

[0089] (1) Material of the resin layer The material of the resin layer is the same as the material of the resin layer in the structure described above.

[0090] (2) Uneven structure The resin layer has an uneven surface structure. Details of the uneven structure will be described later in the section on preferred embodiments of the gas resistance reduction structure.

[0091] (3) Structure of the resin layer It is preferable that the resin layer is distributed across the entire surface of one side of the resin member. When the resin layer is distributed across the entire surface of one side of the resin member, there is a concern that cracks and peeling may easily occur in the resin layer when the resin member is stretched. However, as described above, if the polymer contained in the resin layer has a first structural unit and a second structural unit, it is possible to suppress the occurrence of cracks and peeling in the resin layer when the resin member is stretched.

[0092] (4) Method for forming a resin layer Methods for forming a resin layer having an uneven surface include, for example, applying a curable resin composition to a mold, adhering a resin member to the coating film, curing the curable resin composition by irradiation with ultraviolet light, and then peeling it off the mold; and applying a curable resin composition onto a resin member, pressing a mold against the coating film, curing the curable resin composition by irradiation with ultraviolet light, and then peeling it off the mold. These methods are collectively known as the photopolymer method (2P method). Another method for forming a resin layer having an uneven surface is the lithography method, in which a curable resin composition is applied to a resin member, and then irradiated in a pattern with ionizing radiation such as ultraviolet light, visible light, or electron beams to develop the material. Yet another method for forming a resin layer having an uneven surface is applying a curable resin composition to a resin member, embossing the coating film, and then curing the curable resin composition by irradiation with ultraviolet light.

[0093] The method for applying the curable resin composition is not particularly limited as long as it can be applied uniformly to the resin member, and general application methods can be used.

[0094] Among these methods, the photopolymerization method is preferred, and a more preferred method involves applying a curable resin composition to a mold, adhering a resin component to the coating, curing the resin composition by irradiating it with ultraviolet light, and then peeling it off the mold. This is because it allows for the easy formation of high aspect ratio protrusions.

[0095] 2. Resin components The resin component in this disclosure contains polyvinyl chloride resin. The resin component is the same as the resin component in the structure described above.

[0096] 3. Embodiment of a Gas Resistance Reduction Structure The gas resistance reduction structure described herein has three preferred embodiments. Each embodiment is described below.

[0097] (1) First Embodiment A first embodiment of the gas resistance reduction structure in this disclosure comprises a resin member and a resin layer disposed on one surface of the resin member in contact with the resin member, wherein the gas resistance reduction structure has a first region having an uneven structure on the surface of the resin layer and a second region adjacent to the first region, and the first region and the second region extend in a band shape in a second direction intersecting the first direction.

[0098] This embodiment utilizes a technique that generates vortices at the boundary between a rough surface and a smooth surface to suppress flow separation. When gas flows along a rough surface and a smooth surface, the frictional resistance of the rough surface is greater than that of the smooth surface. Therefore, the gas flow velocity is faster on the smooth surface and slower on the rough surface, resulting in a difference in gas flow velocity between the smooth and rough surfaces. As a result, vortices are generated at the boundary between the rough and smooth surfaces. In this embodiment, the first region has an uneven structure and is a region with high gas frictional resistance. On the other hand, the second region is a region with low gas frictional resistance. Therefore, when gas flows along the resin layer side of the gas resistance reduction structure, vortices are generated at the boundary between the first region and the second region.

[0099] As described above, the second region is a region where the frictional resistance of the gas is smaller compared to the first region. The second region has, for example, a flat surface without an uneven structure. Alternatively, the second region may have an uneven structure, in which case the height of the protrusions in the second region is smaller than the height of the protrusions in the first region.

[0100] Figures 3(a) to 3(c) and 4 are schematic plan views, cross-sectional views, and perspective views showing an example of a gas resistance reduction structure of this embodiment. Figure 3(b) is a cross-sectional view along line AA in Figure 3(a), Figure 3(c) is a cross-sectional view along line BB in Figure 3(a), and Figure 4 is a perspective view of Figure 3(a). As shown in Figures 3(a) to 3(c) and 4, in the gas resistance reduction structure 10A, a first region 11 having an uneven structure including convex portions 5 and concave portions 6, and a second region 12 are alternately arranged in the first direction d1.

[0101] Figures 5(a) and 5(b) are schematic diagrams illustrating the flow of gas in the gas resistance reduction structure of this embodiment, with Figure 5(b) being a cross-sectional view along line AA in Figure 5(a). As shown in Figure 5(a), when gas F flows along the surface of the gas resistance reduction structure 10A, as shown in Figure 5(b), the flow direction d of gas F between the first region 11 and the second region 12 F A vortex V is generated near the boundary parallel to the first region. The generation of vortex V suppresses the separation of the gas F flow from the surface of the gas resistance reduction structure 10A. When an object is placed in a gas flow, the drag forces acting on the object include, for example, frictional resistance and pressure resistance. Frictional resistance is generated by friction between the gas and the surface. Pressure resistance is generated by the pressure difference between the front and back. In other words, pressure resistance is generated by flow separation. In this embodiment, the focus is on reducing pressure resistance among the gas resistances. In the gas resistance reduction structure of this embodiment, by generating vortices near the boundary between the first region and the second region, flow separation can be suppressed and gas resistance, especially pressure resistance, can be reduced.

[0102] The following describes the various components of the gas resistance reduction structure of this embodiment.

[0103] (a) First area In this embodiment, the first region has an uneven structure.

[0104] In the gas resistance reduction structure of this embodiment, it is preferable that the height H1 of the protrusions 5 of the uneven structure 7 is within a predetermined range.

[0105] As mentioned above, when an object is placed in a gas flow, the drag forces acting on the object include, for example, frictional resistance and pressure resistance, with pressure resistance arising from flow separation. Pressure resistance is a problem in moving objects such as automobiles, trains, and aircraft, as well as pipes such as ducts and gas pipes, wind turbines, and air conditioning equipment. The gas flow velocity through these objects is, for example, between 3 m / s and 250 m / s (between 10 km / h and 900 km / h).

[0106] In the gas resistance reduction structure of this embodiment, for example, when the flow velocity of the gas flowing through the object is within the above range, the height H1 of the protrusion 5 can be appropriately adjusted within a predetermined range to facilitate the generation of vortices V near the boundary between the first region 11 and the second region 12. As a result, flow separation from the surface of the gas resistance reduction structure can be suppressed, and pressure resistance can be reduced.

[0107] The height of the protrusion is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 50 μm or more. On the other hand, the height of the protrusion is preferably 1000 μm or less, more preferably 800 μm or less, even more preferably 500 μm or less, and particularly preferably 200 μm or less. Specifically, the height of the protrusion is preferably 10 μm or more and 1000 μm or less, more preferably 15 μm or more and 800 μm or less, even more preferably 20 μm or more and 500 μm or less, particularly preferably 20 μm or more and 200 μm or less, and most preferably 50 μm or more and 200 μm or less. As described above, in moving objects such as automobiles, trains, and aircraft, pipes such as ducts and gas pipes, wind turbines, and air conditioning equipment, the flow velocity of the gas flowing through the object is approximately 3 m / s or more and 250 m / s or less, that is, approximately 10 km / h or more and 900 km / h or less. When the flow velocity is within the above range, the height of the protrusion can be appropriately adjusted within that range to facilitate the generation of vortices near the boundary between the first and second regions. For example, the speed of a car is approximately 10 km / h to 120 km / h, and in this case, the flow velocity of the air flowing around the car is approximately 3 m / s to 33 m / s, that is, approximately 10 km / h to 120 km / h. When the flow velocity is within the above range, the height of the protrusion can be appropriately adjusted within the range of 20 μm to 500 μm to facilitate the generation of vortices near the boundary between the first and second regions. Furthermore, by having the height of the protrusion within the above range, the benefit of reducing pressure resistance can be made greater than the increase in frictional resistance due to the first region.

[0108] In the flow around an object, the very thin layer on the object's surface is strongly affected by viscosity. This layer, strongly affected by viscosity, is called the boundary layer. The height of the protrusion is more preferably between 1 / 100 and 1 / 10 of the boundary layer thickness. Furthermore, since the boundary layer thickness decreases as the gas flow velocity increases, it is preferable that the height of the protrusion be lower within the above range as the gas flow velocity increases.

[0109] Here, the height H1 of the protrusion 5 refers to the height from the bottom of the recess 6 in the first region 11 to the top of the protrusion 5, as shown in Figure 3(c), for example. Specifically, as will be described later, if the protrusion in the first region protrudes relative to the surface of the second region, the height of the protrusion refers to the height from the bottom of the recess located between two adjacent protrusions to the top of the protrusion. Also, as will be described later, if the recess in the first region is concave relative to the surface of the second region, the height of the protrusion refers to the height from the bottom of the recess to the top of the protrusion located between two adjacent recesses.

[0110] In the gas resistance reduction structure of this embodiment, it is preferable that the width W1 of the first region 11 in the first direction d1 is within a predetermined range.

[0111] As mentioned above, in the flow around an object, the very thin layer on the object's surface is strongly affected by viscosity. This layer, which is strongly affected by viscosity, is called the boundary layer.

[0112] Figures 6(a) to 6(c) are schematic diagrams showing the relationship between the width of the first region and the width of the second region in the first direction and the vortices generated near the boundary between the first and second regions in a gas resistance reduction structure. In Figures 6(a) to 6(c), δ represents the boundary layer thickness. For example, as shown in Figure 6(a), when the widths W1 of the first region 11 and W2 of the second region 12 in the first direction are large, large vortices V are generated near the boundary between the first region 11 and the second region 12, but the vortices V do not easily wrap around to the central part of the first region 11 and the central part of the second region 12. Also, as shown in Figure 6(c), for example, when the widths W1 of the first region 11 and W2 of the second region 12 in the first direction are small, the vortices V generated near the boundary between the first region 11 and the second region 12 are small, and the vortices V do not easily reach the outer edge of the boundary layer. In these cases, flow separation can be suppressed, but the effect is small.

[0113] In contrast, by setting the width W1 of the first region 11 and the width W2 of the second region 12 in the first direction d1 to a predetermined range, a large vortex V is generated near the boundary between the first region 11 and the second region 12, as shown in Figure 6(b), for example, and vortices V can be generated throughout the entire boundary layer.

[0114] The width of the first region in the first direction is preferably 0.2 mm or more, and more preferably 1 mm or more. On the other hand, the width of the first region in the first direction is preferably 50 mm or less, and more preferably 25 mm or less. Specifically, the width of the first region in the first direction is preferably 0.2 mm or more and 50 mm or less, and more preferably 1 mm or more and 25 mm or less. By having the width of the first region in the first direction within the above range, a large vortex V is generated near the boundary between the first region 11 and the second region 12, as shown in Figure 6(b), for example, and vortex V can be generated throughout the boundary layer.

[0115] It is more preferable that the width of the first region in the first direction is the same as the boundary layer thickness. Furthermore, since the boundary layer thickness decreases as the gas flow velocity increases, it is preferable that the width of the first region in the first direction is smaller within the above range as the gas flow velocity increases.

[0116] The width of the first region in the first direction may be the same as or different from the width of the second region in the first direction, as long as it is within the above range. In particular, it is preferable that the width of the first region in the first direction and the width of the second region in the first direction are the same. In this case, vortices can be generated more efficiently near the boundary between the first and second regions.

[0117] Here, the width W1 of the first region 11 in the first direction d1 refers to the distance from one end to the other end of the first region 11 in the first direction d1, as shown in Figures 3(a) and 3(b). Also, as shown in Figure 3(b), for example, if the surface of the gas resistance reduction structure 10A is flat, the width of the first region in the first direction refers to the width W1 of the first region 11 on the flat surface in the first direction d1. Also, as shown in Figure 7(b), for example, if the surface of the gas resistance reduction structure 10A is curved, the width of the first region in the first direction refers to the width W1 of the first region 11 on the curved surface in the first direction d1.

[0118] In the gas resistance reduction structure of this embodiment, it is preferable that the length L1 of the first region 11 in the second direction d2 is greater than or equal to a predetermined value. This allows for the efficient generation of vortices V near the boundary between the first region 11 and the second region 12.

[0119] The length of the first region in the second direction is 30 mm or more, preferably 50 mm or more. If the length of the first region in the second direction is too short, vortices will be less likely to be generated near the boundary between the first and second regions, potentially reducing the effect of suppressing flow separation. Furthermore, by having the length of the first region in the second direction within the above range, vortices can be efficiently generated near the boundary between the first and second regions. On the other hand, the length of the first region in the second direction is not particularly limited, but for example, 1000 mm or less is preferred, and 200 mm or less is more preferred. If the length of the first region in the second direction is too long, even if pressure resistance can be reduced, frictional resistance will increase, potentially reducing the effect of reducing gas resistance. Also, manufacturing costs may increase. Specifically, the length of the first region in the second direction is preferably 30 mm or more and 1000 mm or less, more preferably 50 mm or more and 1000 mm or less, and even more preferably 50 mm or more and 200 mm or less.

[0120] Here, the length L1 of the first region 11 in the second direction d2 refers to the distance from one end to the other end of the first region 11 in the second direction d2, as shown in Figure 3(a), for example. Specifically, as will be described later, if a convex portion in the first region protrudes relative to the surface of the second region, the length of the first region in the second direction refers to the distance from the end of the convex portion located at one end of the first region in the second direction to the end of the convex portion located at the other end. On the other hand, as will be described later, if a concave portion in the first region is recessed relative to the surface of the second region, the length of the first region in the second direction refers to the distance from the end of the concave portion located at one end of the first region in the second direction to the end of the concave portion located at the other end. Furthermore, if the surface of the gas resistance reduction structure 10A is planar, as shown in Figure 3(c), for example, the length of the first region in the second direction refers to the length L1 of the first region 11 on the plane in the second direction d2, as shown in Figure 3(a), for example. Furthermore, as shown in Figure 7(a), for example, if the surface of the gas resistance reduction structure 10A is curved, the length of the first region in the second direction is the length L1 of the first region 11 on the curved surface in the second direction d2.

[0121] Therefore, in this embodiment, the gas resistance reduction structure has a first region having an uneven structure on the resin layer side surface and a second region adjacent to the first region. The length of the first region in the second direction is greater than or equal to a predetermined value, the height of the protrusions is within a predetermined range, and the width of the first region and the width of the second region in the first direction intersecting the second direction are within a predetermined range. As a result, vortices can be efficiently generated near the boundary between the first and second regions. Furthermore, by generating vortices near the boundary between the first and second regions, the vortices can be enlarged in the direction in which the boundary line between the first and second regions extends. Therefore, flow separation from the surface of the gas resistance reduction structure can be effectively suppressed. Thus, by applying the gas resistance reduction structure of this embodiment to the surface of an object, the pressure resistance among the gas resistances can be reduced. With the above configuration, the benefit of pressure resistance reduction can be made greater than the increase in frictional resistance due to the first region.

[0122] Furthermore, in the first region, the convex portion may protrude relative to the surface of the second region, and the concave portion may be recessed relative to the surface of the second region. Figures 4 and 9(b) show examples where the convex portion 5 of the first region 2 protrudes relative to the surface of the second region 12, and Figures 8 and 10(b) show examples where the concave portion 6 of the first region 2 is recessed relative to the surface of the second region 12.

[0123] In particular, it is preferable that the convex portion protrudes from the surface of the second region. In such a case, it is possible to easily generate vortices near the boundary between the first and second regions.

[0124] When the convex portion protrudes relative to the surface of the second region, typically, as shown in Figure 4, the bottom of the concave portion 5 lies on the same plane as the surface of the second region 12. Conversely, when the concave portion is recessed relative to the surface of the second region, typically, as shown in Figure 8, the top of the convex portion 5 lies on the same plane as the surface of the second region 12.

[0125] The first region has an uneven structure including convex and concave portions. In the first region, it is sufficient that the convex and concave portions are uniformly distributed.

[0126] The planar pattern shape of the convex and concave portions may be, for example, a regular pattern or a random pattern. In the case of a regular pattern, examples include line-shaped, dot-shaped, grid-shaped, and so on.

[0127] Examples of linear patterns include straight lines and wavy patterns such as sine waves and triangular waves. Among these, linear patterns are preferred.

[0128] Furthermore, in dot patterns, possible arrangements of the dots include, for example, parallel arrangements and staggered arrangements.

[0129] Examples of grid-like patterns include square grids, rectangular grids, triangular grids, hexagonal grids, rhombic grids, and parallelogram grids.

[0130] For example, Figure 5 shows an example where the pattern shape of the convex portion 5 in plan view is linear. Figures 9(a) and 9(b) show examples where the pattern shape of the convex portion 5 in plan view is dot-like and arranged in a staggered pattern. Note that Figure 9(b) is a cross-sectional view of Figure 9(a) along line AA. Figures 10(a) and 10(b) show examples where the pattern shape of the concave portion 6 in plan view is dot-like and arranged in a staggered pattern. Note that Figure 10(b) is a cross-sectional view of Figure 10(a) along line AA. Figure 11 also shows an example where the pattern shape of the convex portion 5 in plan view is grid-like and arranged in a rectangular grid pattern.

[0131] When the pattern shape of the convex and concave portions in plan view is linear, it is preferable that the longitudinal direction of the linear pattern of the convex and concave portions intersects with the second direction, and is more preferably substantially perpendicular to the second direction, that is, substantially parallel to the first direction. Specifically, when the pattern shape of the convex and concave portions is linear, it is preferable that the longitudinal direction of the linear pattern of the convex and concave portions intersects with the second direction, and is more preferably substantially perpendicular to the second direction, that is, substantially parallel to the first direction, as shown in Figure 3, for example. That is, it is preferable that the first region has convex and concave portions that extend linearly along the first direction. As will be described later, the gas resistance reduction structure of this embodiment is, for example, as shown in Figure 5(a), in the flow direction d of the gas F. F It is preferable that the first region 11 and the second region 12 are arranged and used so that their boundary lines are substantially parallel. That is, the gas resistance reduction structure of this embodiment is used in the flow direction d of the gas F, as shown in Figure 5(a), for example. F The first direction d1 is approximately perpendicular to the flow direction of the gas F, that is, the flow direction d FIt is preferable to arrange and use the components such that the second direction d2 is substantially parallel to the first direction. Therefore, if the longitudinal direction of the linear patterns of the convex and concave portions intersects with the second direction, the longitudinal direction of the linear patterns of the convex and concave portions can be made to intersect with the gas flow direction. In such cases, vortices can be easily generated near the boundary between the first and second regions. Furthermore, if the longitudinal direction of the linear patterns of the convex and concave portions is substantially perpendicular to the second direction, the longitudinal direction of the linear patterns of the convex and concave portions can be made substantially perpendicular to the gas flow direction. In such cases, vortices can be further easily generated near the boundary between the first and second regions.

[0132] Furthermore, when the longitudinal direction of the linear patterns of the convex and concave portions intersects with the second direction, the angle between the longitudinal direction of the linear patterns and the second direction is preferably, for example, 45° to 135°. Similarly, when the longitudinal direction of the linear patterns of the convex and concave portions intersects with the second direction, the angle between the longitudinal direction of the linear patterns and the second direction is preferably, for example, 45° to 135°.

[0133] In other words, when the longitudinal direction of the linear patterns of the convex and concave portions intersects with the gas flow direction, the angle between the longitudinal direction of the linear patterns and the gas flow direction is preferably, for example, 45° to 135°. Similarly, when the longitudinal direction of the linear patterns of the convex and concave portions intersects with the gas flow direction, the angle between the longitudinal direction of the linear patterns and the gas flow direction is preferably, for example, 45° to 135°.

[0134] Here, the longitudinal direction of the linear patterns of the convex and concave portions is said to be approximately parallel to the first direction if the angle between the longitudinal direction of the linear patterns and the first direction is between -5° and 5°. Similarly, the longitudinal direction of the linear patterns of the convex and concave portions is said to be approximately parallel to the first direction if the angle between the longitudinal direction of the linear patterns and the first direction is between -5° and 5°.

[0135] Furthermore, the longitudinal direction of the linear patterns of the convex and concave portions is said to be approximately perpendicular to the gas flow direction if the angle between the longitudinal direction of the linear patterns and the gas flow direction is 85° or more and 95° or less. Similarly, the longitudinal direction of the linear patterns of the convex and concave portions is said to be approximately perpendicular to the gas flow direction if the angle between the longitudinal direction of the linear patterns and the gas flow direction is 85° or more and 95° or less.

[0136] Note that the longitudinal direction of a linear pattern refers to the direction in which the linear pattern extends, for example, in the case of a straight line pattern, or the direction in which the wavy line pattern extends, in the case of a wavy line pattern.

[0137] Therefore, the angle between the longitudinal direction of the linear pattern and the second direction is preferably, for example, 45° or more and 135° or less, more preferably 80° or more and 100° or less, and even more preferably 85° or more and 95° or less. Also, if the line is straight, the angle between the longitudinal direction of the straight pattern and the second direction is preferably, for example, 45° or more and 135° or less, more preferably 80° or more and 100° or less, and even more preferably 85° or more and 95° or less.

[0138] Furthermore, the angle between the longitudinal direction of the linear pattern and the gas flow direction is preferably, for example, 45° to 135°, more preferably 80° to 100°, and even more preferably 85° to 95°. Also, if the line is straight, the angle between the longitudinal direction of the straight pattern and the gas flow direction is preferably, for example, 45° to 135°, more preferably 80° to 100°, and even more preferably 85° to 95°.

[0139] When the plan view pattern shape of the convex and concave portions is linear, the width of the linear convex portion is preferably, for example, 1 to 2 times the height of the convex portion. Specifically, when the pattern shape of the convex portion is straight, the width of the straight convex portion is preferably 1 to 2 times the height of the convex portion. If the width of the linear convex portion is too small, it may be difficult to form the first region. Also, if the width of the linear convex portion is too large, it may be difficult to generate sufficient vortices near the boundary between the first and second regions.

[0140] Here, the width of the linear protrusion is the width W3 of the protrusion 5, as shown in Figures 12(a) to (i), and refers to the widest width of the protrusion 5.

[0141] Furthermore, if the pattern shape of the convex portion in plan view is linear, the width of the linear recess is preferably, for example, 1 or more times the height of the convex portion, and more preferably 4 or more times. On the other hand, the width of the linear recess is preferably, for example, 12 times or less the height of the convex portion, and more preferably 10 times or less. Furthermore, the width of the linear recess is preferably, for example, 1 to 12 times the height of the convex portion, and more preferably 4 to 10 times. Specifically, if the pattern shape of the convex portion in plan view is linear, the width of the linear recess is preferably, for example, 1 or more times the height of the convex portion, and more preferably 4 or more times. On the other hand, the width of the linear recess is preferably, for example, 12 times or less the height of the convex portion, and more preferably 10 times or less. Furthermore, the width of the linear recess is preferably, for example, 1 to 12 times the height of the convex portion, and more preferably 4 to 10 times. If the width of the linear recesses is too small, the density of the convex areas will be high, making it difficult to generate sufficient vortices near the boundary between the first and second regions. Conversely, if the width of the linear recesses is too large, the density of the convex areas will be low, also making it difficult to generate sufficient vortices near the boundary between the first and second regions. Furthermore, if the width of the linear recesses is between 4 and 10 times the height of the convex areas, vortices can be generated near the boundary between the first and second regions, effectively suppressing flow separation.

[0142] Here, the width of the linear recess is the width W4 of the recess 6, as shown in Figures 12(a) to (i), and refers to the smallest width of the recess 6. For example, in Figures 12(d), (g) to (i), the width of the recess 6 is zero.

[0143] Furthermore, when the pattern shape of the convex and concave portions in plan view is linear, the pitch of the linear convex portions is preferably, for example, 2 times or more the height of the convex portion, and more preferably 5 times or more. On the other hand, the pitch of the linear convex portions is preferably, for example, 14 times or less the height of the convex portion, and more preferably 12 times or less. Furthermore, the pitch of the linear convex portions is preferably, for example, 2 times or more and 14 times or less the height of the convex portion, and more preferably 5 times or more 12 times or less. Specifically, when the pattern shape of the convex portion in plan view is linear, the pitch of the linear convex portions is preferably, for example, 2 times or more the height of the convex portion, and more preferably 5 times or more. On the other hand, the pitch of the linear convex portions is preferably, for example, 14 times or less the height of the convex portion, and more preferably 12 times or less. Furthermore, the pitch of the linear convex portions is preferably, for example, 2 times or more and 14 times or less the height of the convex portion, and more preferably 5 times or more 12 times or less. If the pitch of the linear protrusions is too small, the density of the protrusions will be high, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Conversely, if the pitch of the linear protrusions is too large, the density of the protrusions will be low, which may also make it difficult to generate sufficient vortices near the boundary between the first and second regions.

[0144] Here, the pitch of the linear protrusions is the pitch P1 of the protrusions 5, as shown in Figures 12(a) to (i), and refers to the distance between adjacent protrusions 5.

[0145] Furthermore, if the pattern shape of the convex portion in plan view is dot-like, the size of the dot-like convex portion in plan view is preferably, for example, 1 to 2 times the height of the convex portion. If the size of the dot-like convex portion is too small, it may be difficult to form the first region. Also, if the size of the dot-like convex portion is too large, it may be difficult to generate sufficient vortices near the boundary between the first and second regions.

[0146] Furthermore, if the pattern shape of the recess in plan view is dot-shaped, the size of the dot-shaped recess in plan view is preferably 1 or more times the height of the convex portion, and more preferably 4 or more times. On the other hand, the size of the dot-shaped recess in plan view is preferably 12 times or less the height of the convex portion, and more preferably 10 times or less. Furthermore, the size of the dot-shaped recess in plan view is preferably 1 to 12 times the height of the convex portion, and more preferably 4 to 10 times. If the size of the dot-shaped recess is too small, the density of the convex portion becomes high, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Also, if the size of the dot-shaped recess is too large, the density of the convex portion becomes low, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Furthermore, if the size of the dot-shaped recess is 4 to 10 times the height of the convex portion, vortices can be generated near the boundary between the first and second regions, and flow separation can be effectively suppressed.

[0147] Here, the size of a dot-shaped protrusion in plan view refers to, for example, the diameter if the plan view shape of the protrusion is circular, the major axis if the plan view shape of the protrusion is elliptical, and the length of the diagonal if the plan view shape of the protrusion is rectangular. Similarly, the size of a dot-shaped recess in plan view refers to, for example, the diameter if the plan view shape of the recess is circular, the major axis if the plan view shape of the recess is elliptical, and the length of the diagonal if the plan view shape of the recess is rectangular.

[0148] Furthermore, if the pattern shape of the convex or concave portion in plan view is dot-shaped, the pitch of the dot-shaped convex or concave portion is preferably, for example, 2 times or more the height of the convex portion, and more preferably 5 times or more. On the other hand, the pitch of the dot-shaped convex or concave portion is preferably, for example, 14 times or less the height of the convex portion, and more preferably 12 times or less. Furthermore, the pitch of the dot-shaped convex or concave portion is preferably, for example, 2 times or more and 14 times or less the height of the convex portion, and more preferably 5 times or more and 12 times or less. If the pitch of the dot-shaped convex or concave portion is too small, the density of the convex portion will be high, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Also, if the pitch of the dot-shaped convex or concave portion is too large, the density of the convex portion will be low, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions.

[0149] Here, the pitch of the dot-shaped protrusions refers to the distance between adjacent protrusions. Similarly, the pitch of the dot-shaped recesses refers to the distance between adjacent recesses.

[0150] Furthermore, if the pattern shape of the convex portion in plan view is grid-like, the width of the grid-like convex portion is preferably, for example, 1 to 2 times the height of the convex portion. If the width of the grid-like convex portion is too small, it may be difficult to form the first region. Also, if the width of the grid-like convex portion is too large, it may be difficult to generate sufficient vortices near the boundary between the first and second regions.

[0151] Furthermore, if the pattern shape of the convex portion in plan view is grid-like, the spacing between the grid-like convex portions is preferably, for example, 1 or more times the height of the convex portion, and more preferably 4 or more times. On the other hand, the spacing between the grid-like convex portions is preferably, for example, 12 times or less the height of the convex portion, and more preferably 10 times or less. Furthermore, the spacing between the grid-like convex portions is preferably, for example, 1 to 12 times the height of the convex portion, and more preferably 4 to 10 times. If the spacing between the grid-like convex portions is too small, the density of the convex portions will be high, and it may become difficult to generate sufficient vortices near the boundary between the first and second regions. Conversely, if the spacing between the grid-like convex portions is too large, the density of the convex portions will be low, and it may become difficult to generate sufficient vortices near the boundary between the first and second regions. Furthermore, when the spacing between the grid-like convex portions is 4 to 10 times the height of the convex portion, vortices can be generated near the boundary between the first and second regions, and flow separation can be effectively suppressed.

[0152] Furthermore, if the pattern shape of the recess in plan view is grid-like, the width of the grid-like recess is preferably 1 or more times the height of the convex portion, and more preferably 4 or more times. On the other hand, the width of the grid-like recess is preferably 12 times or less the height of the convex portion, and more preferably 10 times or less. Furthermore, the width of the grid-like recess is preferably 1 to 12 times the height of the convex portion, and more preferably 4 to 10 times. If the width of the grid-like recess is too small, the density of the convex portion becomes high, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Also, if the width of the grid-like recess is too large, the density of the convex portion becomes low, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Furthermore, if the width of the grid-like recess is 4 to 10 times the height of the convex portion, vortices can be generated near the boundary between the first and second regions, and flow separation can be effectively suppressed.

[0153] Furthermore, if the pattern shape of the convex or concave portion in plan view is grid-like, the pitch of the grid-like convex or concave portion is preferably, for example, 2 times or more, and more preferably 5 times or more, the height of the convex portion. On the other hand, the pitch of the grid-like convex or concave portion is preferably, for example, 14 times or less, and more preferably 12 times or less, the height of the convex portion. Furthermore, the pitch of the grid-like convex or concave portion is preferably, for example, 2 times or more and 14 times or less, and more preferably 5 times or more and 12 times or less, the height of the convex portion. If the pitch of the grid-like convex or concave portion is too small, the density of the convex portion becomes high, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions. Also, if the pitch of the grid-like convex or concave portion is too large, the density of the convex portion becomes low, which may make it difficult to generate sufficient vortices near the boundary between the first and second regions.

[0154] The dimensions of the first region, the convex portion, and the concave portion are measured using a laser displacement sensor.

[0155] Furthermore, the cross-sectional shapes of the convex and concave portions are not particularly limited and include, for example, rectangular, trapezoidal, triangular, semicircular, and semielliptical shapes. For example, Figure 12(a) shows an example where the cross-sectional shapes of the convex portion 5 and concave portion 6 are rectangular, Figure 12(b) shows an example where the cross-sectional shapes of the convex portion 5 and concave portion 6 are trapezoidal, Figures 12(c) to 12(e) show an example where the cross-sectional shape of the convex portion 5 is triangular, Figure 12(f) shows an example where the cross-sectional shape of the convex portion 5 is semielliptical, Figures 12(g) to 12(h) show an example where the cross-sectional shape of the concave portion 6 is triangular, and Figure 12(i) shows an example where the cross-sectional shape of the concave portion 6 is semicircular.

[0156] In particular, the cross-sectional shape of the convex or concave portion is preferably trapezoidal, semicircular, or semielliptical. With these shapes, the formation of the first region is easy, and the durability of the first region can be improved.

[0157] Furthermore, the convex portion is preferably the part extending from the top to the side of the convex portion, and the part connected to the top is preferably rounded, that is, has a curved surface.

[0158] Figures 13(a) and 13(b) are schematic cross-sectional views illustrating the protrusions in the gas resistance reduction structure of this embodiment. Figure 13(a) is a schematic cross-sectional view of the protrusions in the first direction, and Figure 13(b) is a schematic cross-sectional view of the protrusions in the second direction.

[0159] As illustrated in Figures 13(a) and 13(b), the convex portion 5 has a rounded shape in the portion 5R that extends from the top 5T to the side portion 5S of the convex portion 5, and connects to the top 5T. In other words, the convex portion 5 has a curved surface in the portion 5R. When the convex portion 5 has a rounded shape in the portion 5R in this way, the scratch resistance and wear resistance of the convex portion 5 can be improved. Furthermore, frictional resistance at the boundary side portion 5R of the convex portion 5 can be suppressed against vortices generated at the boundary between the first region and the second region. Therefore, it is expected that the effect of vortices, that is, the effect of suppressing gas separation from the surface, will be further enhanced.

[0160] In the above-mentioned portion of the protrusion, the radius of curvature of the curved surface is preferably, for example, 10 μm or more, and more preferably 20 μm or more. On the other hand, the radius of curvature of the curved surface is preferably, for example, 400 μm or less, and more preferably 200 μm or less. Specifically, the radius of curvature of the curved surface is preferably 10 μm or more and 400 μm or less, and more preferably 20 μm or more and 200 μm or less. If the radius of curvature of the curved surface is excessively small, it may become difficult to improve the scratch resistance and wear resistance of the gas resistance reduction structure. Also, if the radius of curvature of the curved surface is excessively large, the height of the protrusion must also be increased. If the height of the protrusion exceeds a size suitable for reducing gas resistance, the gas resistance reduction effect may become insufficient.

[0161] Here, the radius of curvature of the curved surface at the above-mentioned portion of the convex portion refers to the radius of curvature of the curve at the above-mentioned portion of the convex portion in a cross-section in the thickness direction of the gas resistance reduction structure. For example, Figure 13(a) is a cross-sectional view of the gas resistance reduction structure in the thickness direction, and is a cross-sectional view of the convex portion in the first direction. Also, for example, Figure 13(b) is a cross-sectional view of the gas resistance reduction structure in the thickness direction, and is a cross-sectional view of the convex portion in the second direction. In Figures 13(a) and 13(b), the radius of curvature of the curved surface at the above-mentioned portion 5R of the convex portion 5 is the radius of curvature r1 of the curve at the above-mentioned portion 5R of the convex portion 5.

[0162] Furthermore, in the first region, the number of protrusions is multiple and is appropriately set to satisfy the dimensions of the first region, protrusions, and recesses described above. Specifically, the number of protrusions in the first region is 14 or more, may be 83 or more, or may be 181 or more. On the other hand, the number of protrusions is, for example, 1500 or less, may be 714 or less, or may be 200 or less. Specifically, the number of protrusions is 14 or more and 1500 or less, may be 83 or more and 714 or less, or may be 181 or more and 200 or less. By having the number of protrusions within the above range, the reduction of pressure resistance can be maximized and the increase in frictional resistance can be minimized. This makes it possible to maximize the effect of reducing air resistance.

[0163] The plan view shape of the first region is not particularly limited as long as it is a shape that can generate a vortex near the boundary between the first region and the second region, and examples include a rectangular shape and an arc shape. For example, Figure 3(a) is an example in which the plan view shape of the first region 11 is rectangular, and Figure 14 is an example in which the plan view shape of the first region 11 is rectangular and an arc shape. Among these, the plan view shape of the first region is preferably rectangular.

[0164] (b) Second area In this embodiment, the second region is adjacent to the first region.

[0165] The width of the second region in the first direction is 0.2 mm or more, preferably 1 mm or more. On the other hand, the width of the second region in the first direction is 50 mm or less, preferably 25 mm or less. Specifically, the width of the second region in the first direction is preferably 0.2 mm or more and 50 mm or less, and 1 mm or more and 25 mm or less. By having the width of the second region in the first direction within the above range, a large vortex V is generated near the boundary between the first region 11 and the second region 12, as shown in Figure 6(b), for example, and vortices V can be generated throughout the boundary layer.

[0166] It is more preferable that the width of the second region in the first direction is the same as the boundary layer thickness. Furthermore, since the boundary layer thickness decreases as the gas flow velocity increases, it is preferable that the width of the second region in the first direction is smaller within the above range as the gas flow velocity increases.

[0167] Here, the width W2 of the second region 12 in the first direction d1 refers to the distance from one end to the other end of the second region 12 in the first direction d1, in a second region 12 located between adjacent first regions 11, as shown in Figures 3(a) and 3(b). Furthermore, if the surface of the gas resistance reduction structure 10A is flat, as shown in Figure 3(b), the width of the second region in the first direction refers to the width W2 of the second region 12 on the flat surface in the first direction d1. Furthermore, if the surface of the gas resistance reduction structure 10A is curved, as shown in Figure 7(b), the width of the second region in the first direction refers to the width W2 of the second region 12 on the curved surface in the first direction d1.

[0168] (c) Area 1 and Area 2 The gas resistance reduction structure of this embodiment has a first region and a second region adjacent to the first region on the resin layer side, and the first and second regions extend in a strip shape in a second direction intersecting the first direction.

[0169] In this embodiment, since vortices are generated near the boundary between the first and second regions, it is sufficient to have at least one first region and at least one second region. In particular, it is preferable that the first and second regions are arranged alternately in the first direction.

[0170] When the first and second regions are arranged alternately in the first direction, for example, the first and second regions may be arranged alternately parallel to each other in the first direction, or alternately non-parallel to each other in the first direction. For example, Figure 3(a) shows an example where the first region 11 and the second region 12 are arranged alternately parallel to each other in the first direction d1, and Figure 14 shows an example where the first region 11 and the second region 12 are arranged alternately non-parallel to each other in the first direction d1. For example, when applying a gas resistance reduction structure to the three-dimensional curved surface of an object, the first and second regions may be arranged alternately non-parallel to each other in the first direction. Among these, it is preferable that the first and second regions are arranged alternately parallel to each other in the first direction.

[0171] (d) First direction and second direction The first direction intersects the second direction. In particular, it is preferable that the first direction is perpendicular to the second direction. The angle between the first direction and the second direction is preferably 85° or more and 95° or less, and more preferably 90°.

[0172] The gas resistance reduction structure of this embodiment is preferably used in such a configuration that the angle between the boundary line between the first and second regions and the direction of gas flow is, for example, 0°±15°, that is, -15° or more and 15° or less. In other words, the gas resistance reduction structure of this embodiment is preferably used in such a configuration that the angle between the second direction and the direction of gas flow is, for example, 0°±15°, that is, -15° or more and 15° or less. To put it another way, the gas resistance reduction structure of this embodiment is preferably used in such a configuration that the angle between the first direction and the direction of gas flow is, for example, 90°±15°, that is, 75° or more and 105° or less.

[0173] In particular, the gas resistance reduction structure of this embodiment, as shown in Figure 5(a), for example, has a boundary line between the first region 11 and the second region 12 in the flow direction d of the gas F. F It is more preferable that the gas resistance reduction structure of this embodiment be positioned and used so as to be substantially parallel to the flow direction d of the gas F, as shown in Figure 5(a). F It is more preferable that the second direction d2 be approximately parallel to the first direction d1, that is, that the first direction d1 be approximately perpendicular to the second direction d1. This makes it easier to generate vortices near the boundary between the first and second regions, and suppresses flow separation.

[0174] Here, the boundary line between the first and second regions is said to be approximately parallel to the gas flow direction if the angle between the boundary line between the first and second regions and the gas flow direction is between -5° and 5°. The second direction is said to be approximately parallel to the gas flow direction if the angle between the second direction and the gas flow direction is between -5° and 5°. The first direction is said to be approximately perpendicular to the gas flow direction if the angle between the first direction and the gas flow direction is between 85° and 95°.

[0175] Therefore, it is preferable that the gas resistance reduction structure of this embodiment is arranged and used such that the angle between the second direction and the gas flow direction is, for example, -15° or more and 15° or less, more particularly -10° or more and 10° or less, and especially -5° or more and 5° or less.

[0176] In other words, the gas resistance reduction structure of this embodiment is preferably used in such a configuration that the angle between the first direction and the gas flow direction is, for example, 75° to 105°, more particularly 80° to 100°, and especially 85° to 95°.

[0177] If the gas resistance reduction structure of this embodiment is a film, as will be described later, it is preferable that the elongation in the first direction is smaller than the elongation in the second direction in the film-like gas resistance reduction structure. In other words, it is more preferable that the elongation in the first direction is smaller than the elongation in any other direction in the film-like gas resistance reduction structure.

[0178] When a film-like gas resistance reducing structure possesses such physical properties, it can conform to the surface of an object and, even when stretched in a second direction, prevent damage to the uneven structure constituting the gas resistance reducing structure. Therefore, by applying the film-like gas resistance reducing structure to the surface of an object, especially the surface of an object with a curved surface, gas resistance can be effectively reduced.

[0179] For example, as shown in Figures 3 and 4, if the protrusion 5 has a shape that extends linearly along the first direction d1, it is preferable that the film-like gas resistance reducing structure has little elongation in the first direction d1. If the protrusion 5 is made of a material that does not have flexibility with respect to elongation, when the film-like gas resistance reducing structure is stretched in the first direction d1, the protrusion 5 may not be able to withstand the stretching, and collapse or peeling may occur.

[0180] On the other hand, in a direction intersecting the first direction d1, for example, the second direction d2, even if the film-like gas resistance reducing structure is stretched in the second direction d2, the recesses 6 between the multiple arranged protrusions 5 also stretch, so the possibility of collapse or peeling of the protrusions 5 is lower compared to when it is stretched in the first direction d1.

[0181] Therefore, in a film-like gas resistance reducing structure, it is preferable that the elongation in the first direction is smaller than the elongation in the second direction.

[0182] Furthermore, many trucks, buses, and trains, for example, have corners that connect a planar front section, which is roughly perpendicular to the ground, to a planar side section, which is also roughly perpendicular to the ground, and these corners usually have a small radius of curvature. In sections including such corners, air, which is a gas, flows from the front section to the side section. Therefore, as described above, it is preferable to attach the film-like gas resistance reduction structure so that the second direction and the direction of gas flow are roughly parallel. For example, the film-like gas resistance reduction structure is attached so that the second direction is in the direction from the front section to the side section along the curved surface of the corner with a small radius of curvature. For example, Figure 15 shows an example of applying the film-like gas resistance reduction structure 10A to the above-mentioned location on truck 50A.

[0183] In this case, the film-like gas resistance reducing structure may be stretched in a second direction along a curved surface with a small radius of curvature at its corners. Therefore, from the viewpoint of facilitating application, it is preferable that the film-like gas resistance reducing structure has a certain degree of elongation in the second direction.

[0184] On the other hand, in the above case, the film-like gas resistance reducing structure is not stretched in the first direction, so a particularly large elongation is not required.

[0185] Therefore, when a film-like gas resistance reducing structure is applied to the surface of an object with a curved surface, the gas resistance can be effectively reduced because the elongation in the first direction is smaller than the elongation in the second direction.

[0186] Furthermore, in the manufacturing method of the film-like gas resistance reducing structure, a cylindrical plate may be used to form the first region. For example, a cylindrical plate can be used in the photopolymerization method or embossing described above. Using a cylindrical plate is preferable for mass production.

[0187] In particular, as shown in Figures 3 and 4, when the protrusion 5 has a shape that extends linearly along the first direction d1, it is preferable to form the protrusion 5 using a cylindrical plate that rotates along the first direction d1. By making the rotation direction of the cylindrical plate the same as the longitudinal direction of the protrusion 5, that is, the same as the first direction, it is possible to suppress the destruction of the protrusion 5 when it is released from the cylindrical plate. In other words, it is possible to reduce the formation of defective protrusions 5.

[0188] For example, as shown in Figure 16, when forming a protrusion 5 having a linear shape extending along the first direction d1 using a cylindrical plate 110A that rotates along the second direction d2, the direction in which the film flows due to the rotation of the cylindrical plate 110A (second direction d2) is different from the longitudinal direction of the protrusion 5 (first direction d1). Therefore, the resistance that the formed protrusion 5 receives from the cylindrical plate 110A when it is released from the mold is large. Consequently, there is a possibility that the protrusion 5 may be destroyed by the cylindrical plate 110A. Note that in the example shown in Figure 16, the film-like gas resistance reduction structure 10A has a long shape along the second direction d2.

[0189] On the other hand, as shown in Figure 17, when a cylindrical plate 110B that rotates along a first direction d1 is used to form a protrusion 5 that has a linear shape extending along the first direction d1, the direction in which the film flows due to the rotation of the cylindrical plate 110B and the longitudinal direction of the protrusion 5 (first direction d1) are the same. Therefore, the resistance that the formed protrusion 5 receives from the cylindrical plate 110B when it is released from the mold is small. Thus, the destruction of the protrusion 5 by the cylindrical plate 110B is suppressed. In the example shown in Figure 17, the film-like gas resistance reducing structure 10A has a long shape along the first direction d1.

[0190] Therefore, the film-like gas resistance reducing structure has a long form along the first direction, and by using a cylindrical plate that rotates along the first direction to form the protrusions, defects in the formation of the protrusions can be suppressed.

[0191] When a convex portion is formed using a cylindrical plate that rotates along the first direction, as described above, the film-like gas resistance reducing structure has a long form along the first direction. Generally, it is preferable to mass-produce films using a roll-to-roll method. Therefore, it is preferable for the film-like gas resistance reducing structure to be in a rolled form for ease of manufacturing and transportation. Furthermore, it is preferable that the winding direction is in a direction that matches the characteristics of the film-like gas resistance reducing structure. In order to prevent adverse effects from tensile forces acting on the film-like gas resistance reducing structure, it is preferable that the elongation in the winding direction of the film-like gas resistance reducing structure be small.

[0192] For example, the roll body 100A shown in Figure 18 is a roll body in which a film-like gas resistance reducing structure 10A is wound around a winding core 101. In the roll body 100A, the film-like gas resistance reducing structure 10A is wound along a first direction d1. In the film-like gas resistance reducing structure, if the elongation in the first direction d1 on the first surface is smaller than the elongation in a direction intersecting the first direction d1 on the first surface, for example, in a second direction d2, then when forming the roll body 100A, winding the film-like gas resistance reducing structure 10A along the first direction d1 can suppress excessive elongation of the film-like gas resistance reducing structure 10A. In the example shown in Figure 18, the film-like gas resistance reducing structure 10A has a long form along the first direction d1.

[0193] On the other hand, for example, the roll body 100B shown in Figure 19 is a roll body in which a film-like gas resistance reduction structure 10A is wound along a second direction d2. In the film-like gas resistance reduction structure, if the elongation in the first direction d1 on the first surface is smaller than the elongation in a direction intersecting the first direction d1 on the first surface, for example, in a second direction d2, then winding the film-like gas resistance reduction structure 10A along the second direction d2 may cause the film-like gas resistance reduction structure 10A to stretch excessively. In the example shown in Figure 19, the film-like gas resistance reduction structure 10A has a long form along the second direction d2.

[0194] Furthermore, because the film-like gas resistance reducing structure 10A is held in the state of a roll body 100B, that is, because the film-like gas resistance reducing structure 10A is held in a state of being excessively stretched in the second direction d2, there is a possibility that the stretch in the second direction d2 has already decreased in the film-like gas resistance reducing structure 10A that has been unwound from the roll body 100B. In the case of the film-like gas resistance reducing structure 10A with reduced stretch in the second direction d2, the effect when applied to the corners connecting the front and side parts of trucks, buses, trains, etc., as described above will be reduced.

[0195] Therefore, when a film-like gas resistance reducing structure is used as a roll, if the elongation in the first direction is less than the elongation in the second direction, excessive elongation of the film-like gas resistance reducing structure during winding can be suppressed by winding the film-like gas resistance reducing structure along the first direction.

[0196] Therefore, it is preferable that the film-like gas resistance reducing structure has a long shape along the first direction, and that the elongation in the first direction is smaller than the elongation in the second direction. This suppresses defects in the formation of protrusions when forming them using a cylindrical plate, and also suppresses excessive elongation of the film during winding.

[0197] Here, the term "elongation" refers to the amount of deformation when a tensile force is applied to a material. Specifically, if the original length is L and the amount of deformation is ΔL, then ΔL is called "elongation."

[0198] For example, the relative magnitudes of the "elongation" of a film-like gas resistance-reducing structure in each direction can be compared by performing tensile tests using a tensile testing machine or similar device, applying the same tensile force and speed in each direction, and then comparing the magnitudes of the resulting deformation. In this comparison of elongation, it is not necessary to break the sample (the film-like gas resistance-reducing structure); comparing the magnitudes of deformation due to elongation before breakage is sufficient.

[0199] Furthermore, the magnitude of the "elongation" in each direction of the film-like gas resistance reducing structure may be evaluated by the tensile modulus. The tensile modulus is measured in accordance with JIS K7161-1:2014 (Plastics - Determination of tensile properties - Area 1: General rules) and JIS K7127:1999 (Plastics - Test methods for tensile properties - Part 3: Measurement conditions for films and sheets). In this case, for example, the tensile modulus in each direction is measured by performing a tensile test on the sample (film-like gas resistance reducing structure) in each direction using a tensile testing machine. The conditions for the tensile test are shown below. As a tensile testing machine, for example, the "Instron 5565" manufactured by Instron Japan Co., Ltd. is used. The tensile modulus is defined as the slope between two points on the stress / strain curve at strains of 0.05% and 0.25%.

[0200] <Measurement conditions> • Test specimen: 150mm in length, 25mm in width ·Distance between gauge lines: 75mm • Tensile speed: 50 mm / min • Load cell: 1kN • Number of measurements: 3

[0201] To create such a film-like gas resistance reducing structure, it is preferable that the elongation in a specific direction is smaller than the elongation in a direction intersecting that specific direction, even in the resin members constituting the film-like gas resistance reducing structure. Examples of such resin members include uniaxially stretched resin films. For example, in a uniaxially stretched resin film, the elongation in the stretching direction is smaller than the elongation in a direction intersecting the stretching direction.

[0202] Furthermore, depending on the material of the resin film, whether uniaxially oriented or biaxially oriented, the elongation in the MD (Machine Direction) direction is usually smaller than the elongation in the TD (Transverse Direction) direction during the manufacturing process. For example, biaxially oriented PET (polyethylene terephthalate) film is one such resin film. Therefore, even biaxially oriented resin films can be used if, for example, the elongation in the MD direction is smaller than the elongation in the TD direction, or if the elongation in one direction is smaller than the elongation in the other direction intersecting that direction.

[0203] (2) Second Embodiment The second embodiment of the gas resistance reduction structure in this disclosure has an uneven surface on the entire surface of the resin layer.

[0204] Figures 20(a) and 20(b) are schematic plan view and cross-sectional view, respectively, showing an example of a gas resistance reduction structure according to this embodiment. Figure 20(b) is a cross-sectional view taken along line AA of Figure 20(a). As shown in Figures 20(a) and 20(b), the gas resistance reduction structure 10B has an uneven surface structure 7 including protrusions 5 and recesses 6 on the entire surface of the resin layer 3.

[0205] In the gas resistance reduction structure of this embodiment, the uneven structure generates small vortices, thereby suppressing flow separation and preventing the generation of large vortices, particularly Karman vortices. As a result, pressure resistance, which is a component of gas resistance, can be reduced.

[0206] The following describes the various components of the gas resistance reduction structure of this embodiment.

[0207] (1) Uneven structure The gas resistance reduction structure of this embodiment has an uneven surface including protrusions and recesses on the entire surface of the resin layer. On the surface of the resin layer, it is sufficient that the protrusions and recesses are uniformly distributed.

[0208] The planar pattern shape of the convex and concave portions may be, for example, a regular pattern or a random pattern. In the case of a regular pattern, examples include line-shaped, dot-shaped, grid-shaped, and so on.

[0209] Examples of linear patterns include straight lines, sine waves, triangular waves, and other wave-like patterns.

[0210] Furthermore, in a dot pattern, it is preferable that the arrangement of the dots is such that the gas flow strikes the convex parts, regardless of the direction of the gas flow. An example of such a dot arrangement is a staggered arrangement.

[0211] Examples of grid-like patterns include square grids, rectangular grids, triangular grids, hexagonal grids, rhombic grids, and parallelogram grids.

[0212] For example, Figures 22(a) and 22(b) show examples where the pattern shape of the convex portion 5 in plan view is linear. Note that Figure 22(b) is a cross-sectional view of Figure 22(a) along line AA. Figures 20(a) and 20(b) show examples where the pattern shape of the convex portion 5 in plan view is dot-like and arranged in a staggered pattern. Figures 21(a) and 21(b) show examples where the pattern shape of the concave portion 6 in plan view is dot-like and arranged in a staggered pattern. Note that Figure 21(b) is a cross-sectional view of Figure 21(a) along line AA.

[0213] The cross-sectional shapes of the convex and concave portions are not particularly limited and include rectangular, trapezoidal, triangular, semicircular, and semi-elliptical shapes. Specifically, when the plan view pattern shape of the convex or concave portion is dot-like, examples of dot-like shapes of the convex or concave portion include hemispheres, semiellipsoids, cones, frustums of cones, square pyramids, frustums of square pyramids, triangular pyramids, and frustums of triangular pyramids.

[0214] If the pattern shape of the convex or concave portion in plan view is dot-like, the size of the dot-like convex or concave portion may be the same, or two or more dot-like convex or concave portions of different sizes may be observed.

[0215] If the pattern shape of the convex part in plan view is dot-like, the number of convex parts is, for example, 1 × 10 -4 pieces / mm 2 The above 1 x 10 8 pieces / mm 2 The following is true: 1 × 10 -2 pieces / mm 2 The above 1 x 10 3 pieces / mm 2 The following are also possible. In this case, the size of the convex portion in plan view may be, for example, 1 μm or more and 20 mm or less, or 10 μm or more and 10 mm or less. Also, if the shape of the dot-shaped convex portion is a hemisphere or semiellipsoid, the height of the convex portion may be, for example, 50 nm or more and 20 mm or less, or 50 nm or more and 10 mm or less, or 50 nm or more and 300 μm or less. On the other hand, if the shape of the dot-shaped convex portion is a cone, frustum of a cone, square pyramid, frustum of a square pyramid, triangular pyramid, or frustum of a triangular pyramid, the height of the convex portion may be, for example, 100 nm or more and 1000 mm or less, or 3 μm or more and 500 μm or less. The height of the convex portion refers to the height from the bottom of the concave portion to the top of the convex portion.

[0216] If the pattern shape of the recess in plan view is dot-like, the number of recesses, the size of the recess in plan view, and the depth of the recess are the same as the number of protrusions, the size of the protrusions in plan view, and the height of the protrusions, respectively. The depth of the recess refers to the height from the bottom of the recess to the top of the protrusion.

[0217] Here, the size of a dot-shaped protrusion in plan view refers to, for example, the diameter if the plan view shape of the protrusion is circular, the major axis if the plan view shape of the protrusion is elliptical, and the length of the diagonal if the plan view shape of the protrusion is rectangular. Similarly, the size of a dot-shaped recess in plan view refers to, for example, the diameter if the plan view shape of the recess is circular, the major axis if the plan view shape of the recess is elliptical, and the length of the diagonal if the plan view shape of the recess is rectangular.

[0218] Furthermore, if the pattern shape of the convex portion in plan view is dot-like, the pitch of the dot-like convex portion is set appropriately so that the gas flow hits the convex portion, regardless of the direction of gas flow.

[0219] If the pattern shape of the convex and concave portions in plan view is linear, the width of the linear convex and concave portions may be, for example, 1 μm or more and 20 mm or less, or 10 μm or more and 10 mm or less.

[0220] Furthermore, if the pattern shape of the convex and concave portions in plan view is linear, the pitch of the linear convex and concave portions is set appropriately so that the width of the linear convex portion and the width of the linear concave portion are within the above range.

[0221] Furthermore, if the pattern shape of the convex or concave portion in plan view is grid-like, the width of the grid-like convex or concave portion may be, for example, 1 μm or more and 20 mm or less, or 10 μm or more and 10 mm or less.

[0222] The dimensions of the convex and concave parts are measured using a laser displacement sensor.

[0223] When the pattern shape of the convex and concave portions in plan view is linear, it is preferable that the longitudinal direction of the linear pattern of the convex and concave portions intersects with the gas flow direction, and more preferably is approximately perpendicular to the gas flow direction. Specifically, as shown in Figure 22(a), when the pattern shape of the convex portion 5 is linear, the longitudinal direction of the linear pattern of the convex portion 5 is perpendicular to the gas flow direction d FPreferably, it intersects with respect to the gas flow direction d F and is preferably substantially perpendicular to the gas flow direction. In such a case, since the gas flow hits the convex portion, small vortices are generated by the uneven structure, and the separation of the flow can be suppressed.

[0224] When the longitudinal direction of the linear pattern of the convex portion intersects with respect to the gas flow direction, the angle formed by the longitudinal direction of the linear pattern and the gas flow direction is preferably, for example, 45° or more and 135° or less. Similarly, when the longitudinal direction of the linear pattern of the convex portion intersects with respect to the gas flow direction, the angle formed by the longitudinal direction of the linear pattern and the gas flow direction is preferably, for example, 45° or more and 135° or less.

[0225] Here, when the longitudinal direction of the linear pattern of the convex portion is substantially perpendicular to the gas flow direction, it means that the angle formed by the longitudinal direction of the linear pattern and the gas flow direction is 85° or more and 95° or less. Similarly, when the longitudinal direction of the linear pattern of the convex portion is substantially perpendicular to the gas flow direction, it means that the angle formed by the longitudinal direction of the linear pattern and the gas flow direction is 85° or more and 95° or less.

[0226] The longitudinal direction of the linear pattern means, for example, the direction in which the linear pattern extends in the case of a linear pattern, and the direction in which the wavy pattern extends in the case of a wavy pattern.

[0227] Therefore, the angle formed by the longitudinal direction of the linear pattern and the gas flow direction is preferably, for example, 45° or more and 135° or less, more preferably 80° or more and 100° or less, and even more preferably 85° or more and 95° or less. Also, when the linear shape is linear, the angle formed by the longitudinal direction of the linear pattern and the gas flow direction is preferably, for example, 45° or more and 135° or less, more preferably 80° or more and 100° or less, and even more preferably 85° or more and 95° or less.

[0228] Also, the number of convex portions or concave portions is plural, and is appropriately set so as to satisfy the above dimensions of the convex portions and concave portions.

[0229] (3) Third Embodiment In the third embodiment of the gas resistance reduction structure in the present disclosure, a linear concavo-convex structure is provided on the entire surface of the resin layer.

[0230] FIGS. 23(a) and 23(b) are a schematic plan view and a cross-sectional view showing an example of the gas resistance reduction structure of the present embodiment. FIG. 23(b) is a cross-sectional view taken along line A-A of FIG. 23(a). As shown in FIGS. 23(a) and 23(b), the gas resistance reduction structure 10C has a concavo-convex structure 7 including linear convex portions 5 and concave portions 6 on the entire surface of the resin layer 3.

[0231] In the gas resistance reduction structure of the present embodiment, the linear concavo-convex structure is a so-called riblet. In the gas resistance reduction structure of the present embodiment, the linear concavo-convex structure can reduce the frictional resistance with the gas.

[0232] Hereinafter, each component of the gas resistance reduction structure of the present embodiment will be described.

[0233] (1) Concavo-Convex Structure The gas resistance reduction structure of the present embodiment has a concavo-convex structure including linear convex portions and concave portions on the entire surface of the resin layer. On the surface of the resin layer, the linear convex portions and concave portions may be arranged so as to be uniformly distributed.

[0234] Examples of the linear pattern include a linear pattern and a wavy pattern such as a sine wave.

[0235] The cross-sectional shapes of the convex and concave portions are not particularly limited and include rectangular, trapezoidal, triangular, semicircular, and semi-elliptical shapes. Furthermore, the cross-sectional shapes of the convex and concave portions may have rounded vertices or corners. For example, Figure 23(b) shows an example where the cross-sectional shapes of the convex portion 5 and concave portion 6 are rectangular. Figure 24(a) shows an example where the cross-sectional shapes of the convex portion 5 and concave portion 6 are triangular. Figure 24(b) shows an example where the cross-sectional shape of the convex portion 5 is trapezoidal and the cross-sectional shape of the concave portion 6 is triangular. Figure 24(c) shows an example where the cross-sectional shape of the convex portion 5 is triangular and the cross-sectional shape of the concave portion 6 is trapezoidal. Figure 24(d) shows an example where the cross-sectional shapes of the convex portion 5 and concave portion 6 are trapezoidal.

[0236] As illustrated in Figure 23(b), when the cross-sectional shapes of the protrusion 5 and recess 6 are rectangular, the width W11 of the protrusion 5 may be, for example, 0.1 μm or more and 200 mm or less, or 20 μm or more and 5 mm or less. In this case, the width W12 of the recess 6 may be, for example, 0.1 μm or more and 500 mm or 20 μm or more and 5 mm or less. Also in this case, the height H1 of the protrusion 5 may be, for example, 0.1 μm or more and 100 mm or less, or 3 μm or more and 500 μm or less.

[0237] As illustrated in Figure 24(a), when the cross-sectional shapes of the protrusion 5 and recess 6 are triangular, the width W11 of the protrusion 5 may be, for example, 0.1 μm or more and 500 mm or less, or 20 μm or more and 5 mm or less. In this case, the height H1 of the protrusion 5 may be, for example, 0.1 μm or more and 100 mm or less, or 3 μm or more and 500 μm or less.

[0238] As illustrated in Figure 24(b), when the cross-sectional shape of the convex portion 5 is trapezoidal and the cross-sectional shape of the concave portion 6 is triangular, the width W13 of the upper base of the trapezoidal convex portion 5 may be, for example, 0.01 μm or more and 100 mm or less, or 1 μm or more and 5 mm or less. In this case, the width of the lower base of the trapezoidal convex portion 5, i.e., the width W11 of the convex portion 5, may be, for example, 0.1 μm or more and 200 mm or less, or 20 μm or more and 5 mm or less. Also in this case, the height H1 of the convex portion 5 may be, for example, 0.1 μm or more and 100 mm or less, or 3 μm or more and 500 μm or less.

[0239] As illustrated in Figure 24(c), when the cross-sectional shape of the protrusion 5 is triangular and the cross-sectional shape of the recess 6 is trapezoidal, the width W11 of the protrusion 5 may be, for example, 0.01 μm or more and 100 mm or less, or 1 μm or more and 5 mm or less. In this case, the width W12 of the recess 6 may be, for example, 0.1 μm or more and 200 mm or less, or 20 μm or more and 5 mm or less. Also in this case, the height H1 of the protrusion 5 may be, for example, 0.1 μm or more and 100 mm or less, or 3 μm or more and 500 μm or less.

[0240] As illustrated in Figure 24(d), when the cross-sectional shape of the convex portion 5 and the concave portion 6 is trapezoidal, the width W13 of the upper base of the trapezoidal convex portion 5 may be, for example, 0.01 μm or more and 100 mm or less, or 1 μm or more and 5 mm or less. In this case, the width of the lower base of the trapezoidal convex portion 5, i.e., the width W11 of the convex portion 5, may be, for example, 0.1 μm or more and 200 mm or less, or 20 μm or more and 5 mm or less. In this case, the width W12 of the concave portion 6 may be, for example, 0.01 μm or more and 100 mm or less, or 1 μm or more and 5 mm or less. Also in this case, the height H1 of the convex portion 5 may be, for example, 0.1 μm or more and 100 mm or less, or 3 μm or more and 500 μm or less.

[0241] The dimensions of the convex and concave parts are measured using a laser displacement sensor.

[0242] Preferably, the longitudinal direction of the linear patterns of the convex and concave portions is substantially parallel to the gas flow direction. Specifically, as shown in Figure 23(a), when the pattern shapes of the convex portion 5 and concave portion 6 are linear, the longitudinal direction of the linear patterns of the convex portion 5 and concave portion 6 is substantially parallel to the gas flow direction d F It is preferable that the plane be approximately parallel to the gas. In this case, frictional resistance with the gas can be reduced.

[0243] Furthermore, the number of protrusions or recesses is multiple, and is set appropriately to satisfy the dimensions of the protrusions and recesses described above.

[0244] 4. Morphology of gas resistance reduction structure The form of the gas resistance reducing structure in the present disclosure is not particularly limited, but it is preferably a film. The gas resistance reducing structure can be easily applied to the surface of an object.

[0245] 5. Other configurations When the gas resistance reducing structure in the present disclosure is a film, the film-shaped gas resistance reducing structure may further have other configurations in addition to the resin member and the resin layer. The other configurations are appropriately selected according to the type of the resin member.

[0246] (1) When the resin member is a resin film (a) Adhesive layer For example, as shown in Fig. 25(a), the gas resistance reducing structure 10 in the present disclosure may have an adhesive layer 21 on the surface opposite to the resin layer 3 of the resin member 2. The adhesive layer is a layer for attaching the film-shaped gas resistance reducing structure to the surface of an object. By arranging the adhesive layer, the gas resistance reducing structure can be easily attached to the surface of the object.

[0247] The adhesive used for the adhesive layer is appropriately selected according to the use of the gas resistance reducing structure and the like. For example, acrylic adhesives, urethane adhesives, silicone adhesives, rubber adhesives, and vinyl ether adhesives can be mentioned.

[0248] Also, the adhesive layer may or may not have re-peelability. Among them, it is preferable that the adhesive layer has re-peelability. When the adhesive layer has re-peelability, it is possible to reattach the gas resistance reducing structure to the surface of the object when attaching it, and it is also possible to peel the gas resistance reducing structure from the object without leaving adhesive residue when reattaching or removing the gas resistance reducing structure.

[0249] Note that "re-peelability" refers to the property that after attaching the gas resistance reducing structure to the surface of an object, it can be easily peeled without damaging the object and without leaving adhesive on the object surface.

[0250] Furthermore, the adhesive layer may contain a coloring agent. By including a coloring agent in the adhesive layer, shielding properties can be provided. For example, if an object has a design applied to its surface, and the adhesive layer contains a coloring agent, and the gas resistance reduction structure further has a printed layer as described later, then by attaching the gas resistance reduction structure to the surface of the object, the existing design can be concealed and a new design can be applied.

[0251] The thickness of the adhesive layer is not particularly limited and is selected appropriately depending on the application. For example, when using a gas resistance reduction structure as a wrapping film or marking film for moving objects such as automobiles, trains, and aircraft, the thickness of the adhesive layer is, for example, 5 μm to 50 μm. If the adhesive layer is too thin, the adhesion to the moving object may be insufficient.

[0252] Methods for forming an adhesive layer include, for example, applying an adhesive composition or laminating an adhesive film.

[0253] (b) Printing layer The gas resistance reduction structure in this disclosure may have a printed layer on the side of the resin member opposite to the resin layer. The presence of the printed layer can provide aesthetic appeal.

[0254] The printing layer can display information such as letters, numbers, symbols, pictures, patterns, and marks.

[0255] Furthermore, the method for forming the printed layer may be, for example, by directly printing onto a resin member, such as a resin film, or, as shown in Figure 22(b), the printed layer 23 may be formed by printing onto a support layer 22. The printed layer may be arranged in a pattern on the resin member or support layer, or it may be arranged over the entire surface of the resin member or support layer. Also, the printing method is not particularly limited.

[0256] The support layer is not particularly limited as long as it can be printed on; for example, a resin substrate can be used.

[0257] Furthermore, the support layer may contain a coloring agent. By including a coloring agent in the support layer, shielding properties can be provided. For example, if an object has a design applied to its surface, and the gas resistance reduction structure has a printed layer and the support layer contains a coloring agent, then by attaching the gas resistance reduction structure to the surface of the object, the existing design can be concealed and a new design can be applied.

[0258] The thickness of the support layer is not particularly limited and can be selected as appropriate depending on the application.

[0259] Furthermore, when forming a printed layer by printing on a support layer, for example, as shown in Figure 25(b), a printed sheet having a support layer 22 and a printed layer 23 arranged on one side of the support layer 22 may be separately manufactured and this printed sheet may be bonded to the resin member 2 via a second adhesive layer 24, or a printed layer, a resin member, and a resin layer may be formed sequentially on the support layer.

[0260] 6.Applications The gas resistance reduction structure described herein can be applied to the surface of an object. Specifically, it can be applied to the casings and components of automobiles such as passenger cars, trucks, and buses; railway vehicles such as trains, bullet trains, and locomotives; aircraft such as airplanes, helicopters, and drones; and bicycles, which move through gas. Furthermore, the gas resistance reduction structure described herein can also be applied to the inner surface of pipes such as ducts and gas pipes, the surface of wind turbine blades, and the surface of air outlets or louvers of air conditioning equipment such as air conditioners. In particular, the gas resistance reduction structure described herein is preferably applied to the surface of the casings and components of a moving object, and is especially preferably applied to the surface of a non-streamlined object, specifically a bluff body. This is because in a bluff body, the contribution of pressure resistance to gas resistance is large, and the effects of this disclosure are significantly exhibited. Examples of bluff bodies include trucks and buses.

[0261] Furthermore, when applying the gas resistance reduction structure described herein to the surface of an object, the surface of the object may be flat or curved.

[0262] When applying the gas resistance reduction structure described herein to the surface of an object, for example, a film-like gas resistance reduction structure may be placed on the surface of the object, or the gas resistance reduction structure may be formed directly on the surface of the object.

[0263] The gas resistance reducing structure in this disclosure may be arranged over the entire surface of an object, or on a portion of the surface of an object.

[0264] In particular, it is preferable to place the gas resistance reduction structure in a location where flow separation is likely to occur. The location where flow separation is likely to occur varies depending on the type and shape of the moving object, etc.

[0265] Furthermore, while the gas resistance reduction structure in this disclosure can reduce gas resistance, the gas is not particularly limited. The density of the gas can be, for example, 0.08 kg / m³. 3 More than 10kg / m 3 The following is preferable. Among these, the gas is preferably air.

[0266] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Examples]

[0267] The present disclosure will be further explained below with reference to examples and comparative examples.

[0268] [Examples 1-4 and Comparative Examples 1-20] First, the UV-curable resin compositions shown in Table 1 below were prepared. The values ​​for each component in Table 1 indicate the content (in parts by mass). All polymerization initiators in Table 1 are trade names of IGM Resins. The UV absorbers in Table 1 are trade names of BASF Japan. The light stabilizers in Table 1 are trade names of Nippon Emulsifier Co., Ltd.

[0269] Next, the UV-curable resin composition was applied to a mold having an uneven surface. As the resin film containing polyvinyl chloride resin, Avery Dennison's laminate film "DOL1460" was used. The resin film, with the separator film still attached, was brought into close contact with the coating of the UV-curable resin composition, and after curing the UV-curable resin composition by irradiation with ultraviolet light, it was peeled off the mold. This resulted in a structure having a resin layer with an uneven surface and a resin film containing polyvinyl chloride resin. As described in the first embodiment above, the structure had a first region with an uneven surface and a second region adjacent to the first region on the surface of the resin layer. In the first region, the height of the protrusions was 160 μm, the width of the protrusions was 160 μm, and the width of the recesses was 1120 μm. The width of the first region was 7 mm, and the width of the second region was 7 mm.

[0270] [evaluation] (1) Viscosity The viscosity of the UV-curable resin composition used to form the resin layer was measured at a composition temperature of 25°C using a Type B viscometer ("TVB-10", manufactured by Toki Sangyo Co., Ltd.).

[0271] (2) Stickiness The surface of the resin layer of the structure was touched by hand, and its stickiness was evaluated according to the following criteria. A: No stickiness B: Sticky C: It was extremely sticky, and the resin layer peeled off.

[0272] (3) Adhesion The adhesion of the resin layer was evaluated in accordance with JIS K5600-5-6:1999 (General test methods for paints - Part 5: Mechanical properties of paint films - Section 6: Adhesion (cross-cut method)). Adhesion was evaluated according to the following criteria. A: The test results were classified as 0-1. B: The test results were classified as Category 2-3. C: The test results were classified as Category 4-5.

[0273] [Table 1]

[0274] Table 1 shows that forming a resin layer using a curable resin composition containing a predetermined monomer improves adhesion to a resin component containing polyvinyl chloride resin. Furthermore, when the structures of Examples 2 to 4 were stretched, they exhibited good extensibility. This is because the resin layer was formed using a curable resin composition containing a predetermined monomer and urethane acrylate.

[0275] This disclosure provides the following inventions. [1] A resin component containing polyvinyl chloride resin, The resin member has a resin layer on one of its surfaces, which is positioned in contact with the resin member. A structure wherein the above resin layer contains a polymer having a first structural unit represented by the following formula (1).

[0276] [ka] (In formula (1) above, A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent. [2] The structure according to [1], wherein the polymer contained in the resin layer further comprises a second structural unit including a structure derived from a polymerizable functional group and a urethane bond. [3] The structure according to [2], wherein the second constituent unit includes a structure derived from a polycarbonate polyol. [4] The structure according to any one of [1] to [3], wherein the polymerizable functional group is a (meth)acryloyloxy group. [5] The structure according to any one of [1] to [4], wherein the resin layer contains an ultraviolet absorber. [6] The structure according to any one of [1] to [5], wherein the resin member is a resin film. [7] A resin component containing polyvinyl chloride resin, On one surface of the above-mentioned resin member, a resin layer is disposed in contact with the above-mentioned resin member, A gas resistance reducing structure having, The above gas resistance reducing structure has an uneven surface on the resin layer, A gas resistance reducing structure wherein the resin layer contains a polymer having a first structural unit represented by the following formula (1).

[0277] [ka] (In formula (1) above, A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R 1 ~R 10 Each of these independently represents a hydrogen atom or a substituent. [8] The gas resistance reducing structure according to [7], wherein the polymer contained in the resin layer further comprises a second structural unit including a structure derived from a polymerizable functional group and a urethane bond. [9] The gas resistance reducing structure according to [8], wherein the second constituent unit includes a structure derived from a polycarbonate polyol.

[10] The gas resistance reducing structure according to any one of [7] to [9], wherein the polymerizable functional group is a (meth)acryloyloxy group.

[11] The gas resistance reducing structure according to any one of [7] to

[10] , wherein the resin layer contains an ultraviolet absorber.

[12] The gas resistance reducing structure according to any one of [7] to

[11] , wherein the resin member is a resin film.

[13] The gas resistance reducing structure has a first region having the uneven structure on the surface of the resin layer and a second region adjacent to the first region, A gas resistance reducing structure according to any one of [7] to

[12] , wherein the first region and the second region extend in a band-like manner in a second direction intersecting the first direction.

[14] The gas resistance reducing structure according to

[13] , wherein the first region and the second region are alternately arranged in the first direction.

[15] The gas resistance reducing structure according to any one of [7] to

[12] , wherein the gas resistance reducing structure has the above-mentioned uneven structure on the entire surface of the resin layer. [Explanation of symbols]

[0278] 1 … structure 2… Resin component 3… Resin layer 5 ... protruding part 6… recess 7 … Uneven structure 10, 10A, 10B, 10C… Gas resistance reduction structure 11 … 1st area 12…Second area d1 … 1st direction d2…Second direction H1 ... Height of the protrusion

Claims

1. A resin component containing polyvinyl chloride resin, The resin member has a resin layer disposed in contact with one of its surfaces, A structure wherein the resin layer contains a polymer having a first structural unit represented by the following formula (1). 【Chemistry 1】 (In the above formula (1), A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R １ ~R １０ Each of these independently represents a hydrogen atom or a substituent.

2. The structure according to claim 1, wherein the polymer contained in the resin layer further comprises a second structural unit including a structure derived from a polymerizable functional group and a urethane bond.

3. The structure according to claim 2, wherein the second structural unit includes a structure derived from a polycarbonate polyol.

4. The structure according to claim 1, wherein the polymerizable functional group is an acryloyl group.

5. The structure according to claim 1, wherein the resin layer contains an ultraviolet absorber.

6. The structure according to claim 1, wherein the resin member is a resin film.

7. A resin component containing polyvinyl chloride resin, On one surface of the resin member, a resin layer is disposed in contact with the resin member, A gas resistance reducing structure having, The gas resistance reducing structure has an uneven surface on the resin layer, A gas resistance reducing structure wherein the resin layer contains a polymer having a first structural unit represented by the following formula (1). 【Chemistry 2】 (In the above formula (1), A represents a structure derived from a polymerizable functional group, X represents a direct bond or a divalent linking group, R １ ~R １０ Each of these independently represents a hydrogen atom or a substituent.

8. The gas resistance reducing structure according to claim 7, wherein the polymer contained in the resin layer further comprises a second structural unit including a structure derived from a polymerizable functional group and a urethane bond.

9. The gas resistance reducing structure according to claim 8, wherein the second structural unit includes a structure derived from a polycarbonate polyol.

10. The gas resistance reducing structure according to claim 7, wherein the polymerizable functional group is a (meth)acryloyloxy group.

11. The gas resistance reducing structure according to claim 7, wherein the resin layer contains an ultraviolet absorber.

12. The gas resistance reducing structure according to claim 7, wherein the resin member is a resin film.

13. The gas resistance reducing structure has a first region having the uneven structure on the surface of the resin layer and a second region adjacent to the first region. The gas resistance reducing structure according to claim 7, wherein the first region and the second region extend in a strip-like manner in a second direction intersecting the first direction.

14. The gas resistance reducing structure according to claim 13, wherein the first region and the second region are alternately arranged in the first direction.

15. The gas resistance reducing structure according to claim 7, wherein the gas resistance reducing structure has the uneven structure on the entire surface of the resin layer.

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