JP2017209953A - Water-repellent film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-repellent film excellent in antifouling property.SOLUTION: There is provided a water-repellent film 1 having a substrate 10 and a resin layer 20 arranged on the substrate 10, the resin layer 20 has an uneven structure 21 with a line and space shape having a plurality of line-like protrusions 22, at least one of the plurality of protrusions 22 bends in cycle on a plane view. There is provided a water-repellent film having an angle by 2 tangent lines at 2 inflection points neighboring on a reference line with bending in cycle of 0 of 90 to less than 180° when viewing a wave-shaped protrusion 22 in plane.EFFECT: By the uneven structure 21 arranged on a surface, water-repellency of the water-repellent film 1 is enhanced. Especially by adding the uneven structure to a material having a contact angle of water of 90° or more, a contact angle of the uneven structure to water becomes larger than a contact angle of the material itself to water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water repellent film.

  Conventionally, in order to improve the quick-drying property and antifouling property of a watering device, a water repellent layer is provided on the surface of the device. For example, Patent Document 1 discloses forming irregularities having conical columnar protrusions as convex portions on the surface of a metal substrate.

JP 2010-202955 A

  However, in the above conventional technique, dust and dirt are likely to adhere between the plurality of convex portions, and once attached dust and dirt are difficult to remove. For this reason, in the said prior art, there exists a problem in the antifouling property of a water repellent layer.

  Then, an object of this invention is to provide the water-repellent film excellent in antifouling property.

  In order to achieve the above object, a water-repellent film according to one embodiment of the present invention includes a base material and a resin layer provided on the base material, and the resin layer includes a plurality of linear protrusions. The line-and-space-shaped concavo-convex structure is provided, and at least one of the plurality of convex portions is periodically bent in a plan view.

  ADVANTAGE OF THE INVENTION According to this invention, the water-repellent film excellent in antifouling property can be provided.

It is a perspective view of the water repellent film which concerns on embodiment. It is a top view of the uneven structure of the water repellent film which concerns on embodiment. It is an enlarged view which expands and shows the uneven structure of the water-repellent film which concerns on embodiment in the area | region enclosed with the dashed-dotted line III of FIG. It is sectional drawing of the uneven structure of the water repellent film which concerns on embodiment in the IV-IV line | wire of FIG. It is sectional drawing for demonstrating the relationship between the taper part provided in the root of the convex part of the water repellent film which concerns on embodiment, and water. It is a top view for demonstrating the relationship between the width | variety of the recessed part of the water repellent film which concerns on embodiment, and a mycelium. It is process sectional drawing which shows the manufacturing method of the water repellent film which concerns on embodiment. It is a top view for demonstrating the problem of the uneven structure which concerns on a comparative example. It is a top view of the uneven structure of the water repellent film which concerns on the modification 1 of embodiment. It is a top view of the uneven structure of the water repellent film which concerns on the modification 2 of embodiment.

  Below, the water-repellent film which concerns on embodiment of this invention is demonstrated in detail using drawing. Each of the embodiments described below shows a specific example of the present invention. Therefore, numerical values, shapes, materials, components, arrangement and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Therefore, for example, the scales and the like do not necessarily match in each drawing. Moreover, in each figure, the same code | symbol is attached | subjected about the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

(Embodiment)
[Overview]
First, the outline of the water-repellent film according to the present embodiment will be described with reference to FIG. FIG. 1 is a perspective view of a water-repellent film 1 according to the present embodiment.

  As shown in FIG. 1, the water repellent film 1 includes a base material 10 and a resin layer 20 having an uneven structure 21. The water-repellent film 1 has higher water repellency due to the uneven structure 21 provided on the surface. Specifically, by providing a concavo-convex structure to a material having a water contact angle of 90 ° or more, the contact angle of the concavo-convex structure with respect to water becomes larger than the contact angle of the material itself with respect to water.

  The water-repellent film 1 according to the present embodiment is used for, for example, a watering facility such as a unit bath, or a building material such as an interior material or an outer wall of a bathroom. Specifically, the water-repellent film 1 is used for a sink (a sink), a bathtub, or a flooring material, a ceiling material, a wall material, or the like of a bathroom.

  Below, the structural member of the water repellent film 1 is demonstrated in detail.

[Base material]
The substrate 10 is a member that supports the resin layer 20. The substrate 10 is, for example, a resin film, a metal foil, or a nonwoven fabric. As a material for the resin film, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), or the like can be used. The magnitude | size and shape of the base material 10 are not specifically limited. The base material 10 has an appropriate size and shape according to the purpose of use and the use environment.

[Resin layer]
The resin layer 20 is provided on the base material 10. The resin layer 20 is formed using, for example, an ultraviolet curable resin. As the ultraviolet curable resin, a fluorine resin, a silicone resin, or the like can be used. The thickness of the resin layer 20 is, for example, 1 μm to 50 μm, but is not limited thereto.

  As shown in FIG. 1, the resin layer 20 has a concavo-convex structure 21. The uneven structure 21 is provided on the upper surface of the resin layer 20 and is provided on the uppermost surface of the water-repellent film 1. That is, when the water repellent film 1 is used as a building material or the like, the uneven structure 21 is exposed on the outermost surface.

[Uneven structure]
The uneven structure 21 is a fine uneven structure having a line and space shape. The line-and-space shape is a shape in which a plurality of lines extending substantially parallel to each other are arranged at a predetermined interval. The interval between two adjacent lines corresponds to a line-and-space space. A line is a straight line, a broken line, or a curved line, and the thickness and shape thereof may be uniform (that is, the same as each other) in a plane, or may be non-uniform. The distance between two adjacent lines (that is, the width of the space) may be uniform in the plane or may be non-uniform.

  Specifically, as shown in FIG. 1, the concavo-convex structure 21 has a plurality of convex portions 22 and a plurality of concave portions (grooves) 23. The plurality of protrusions 22 corresponds to a line-and-space line, and the plurality of recesses 23 correspond to a space. The concavo-convex structure 21 is formed by alternately arranging convex portions 22 and concave portions 23. The concavo-convex structure 21 has water slidability by a plurality of convex portions 22 supporting water so that water does not reach (contact) the bottom of the concave portion 23.

  In FIG. 1, the direction in which the convex portions 22 and the concave portions 23 are alternately arranged is the x-axis direction, the thickness direction of the base material 10 is the z-axis direction, and the direction orthogonal to both the x-axis and the z-axis is the direction. The y-axis direction is used. The y-axis direction is a direction in which lines and spaces having a line and space shape extend.

  FIG. 2 is a top view of the concavo-convex structure 21 of the water repellent film 1 according to the present embodiment. FIG. 3 is an enlarged view showing the concavo-convex structure 21 of the water-repellent film 1 according to the present embodiment in the region surrounded by the alternate long and short dash line III in FIG. 2. FIG. 4 is a cross-sectional view of the concavo-convex structure 21 of the water repellent film 1 according to the present embodiment taken along the line IV-IV in FIG.

  The plurality of convex portions 22 according to the present embodiment have substantially the same shape. The convex portion 22 is bent periodically in plan view. Specifically, as shown in FIG. 2, the convex portion 22 has a wave shape that is periodically bent with a substantially constant amplitude in a plan view. Although the waveform which is the planar view shape of the convex part 22 is a sine wave, for example, it is not limited to this. The waveform may be a triangular wave, a sawtooth wave, a rectangular wave, a trapezoidal wave, or the like.

  The width d1 of the convex portion 22 is substantially constant. Specifically, as shown in FIG. 3, the convex portion 22 is bent periodically with a constant width d1 around a center line CL of a wave shape such as a sine wave. The width d1 is, for example, 1 μm to 20 μm, but is not limited thereto. The height h1 of the convex portion 22 (corresponding to the depth h2 of the concave portion 23, see FIG. 4) is, for example, 1 μm to 40 μm, but is not limited thereto.

  In the present embodiment, as shown in FIG. 3, two tangents TL1 and TL2 at two adjacent inflection points IP1 and IP2 on the reference line BL form when the wave-shaped convex portion 22 is viewed in plan. The angle θ is not less than 90 ° and less than 180 °. Note that the reference line BL is a virtual line in which the displacement of the periodic bending of the convex portion 22 is zero. The reference line BL is parallel to the direction in which the line-and-space line extends, that is, the y-axis direction. Thereby, the periodic bending of the convex portion 22 becomes gentle and it becomes difficult to form a liquid pool, so that the antifouling property can be improved.

  The convex part 22 is arrange | positioned so that the space | interval may become substantially fixed with respect to the adjacent convex part 22. FIG. In other words, the width d2 of the recess 23, which is a space between two adjacent protrusions 22, is substantially constant. The concave portion 23 has a wave shape like the convex portion 22 and is periodically bent with a constant width d2. The width d2 is, for example, 2 μm to 40 μm, but is not limited thereto.

  As shown in FIG. 3, a linear space 23 a having a predetermined width parallel to the reference line BL is included between two adjacent convex portions 22, that is, the concave portion 23. In FIG. 3, dots in the plan view of the space 23 a are shaded.

  The width d2a of the space 23a corresponds to the distance between the nearest parts (specifically, the distance in the x-axis direction) when the two adjacent convex portions 22 are viewed in the y-axis direction. That is, in this Embodiment, when the two adjacent convex parts 22 are seen in the y-axis direction, the two convex parts 22 do not contact or overlap. Since the recess 23 is provided with the space 23a, as shown in FIG. 2, the cleaning liquid 90 and the dirt itself are more likely to flow along the y-axis direction, so that the antifouling property can be improved, and The attached dirt can be easily washed off.

  The cleaning liquid 90 is a liquid used for cleaning the surface of the uneven structure 21. The cleaning liquid 90 is, for example, water containing a surfactant such as a detergent. The surface of the concavo-convex structure 21 includes not only the upper surface of the convex portion 22 but also the bottom surface of the concave portion 23 and the side surfaces of the convex portion 22 and the concave portion 23.

  In plan view, the total area of the plurality of convex portions 22 is 50% or less of the total area of the concavo-convex structure 21. The total area of the concavo-convex structure 21 is the sum of the total area of the plurality of convex portions 22 and the total area of the plurality of concave portions 23 in plan view. For example, as shown in FIG. 3, the width d <b> 1 of the convex portion 22 is shorter than the width d <b> 2 of the concave portion 23. Thereby, since the contact area of water and the uneven structure 21 becomes small, water repellency and water slidability can be improved.

  In the present embodiment, a radius is provided at the tip of the convex portion 22. In addition, the front-end | tip of the convex part 22 is a front-end | tip of a height direction (z-axis direction). In the present embodiment, since the cross-sectional shape (xz cross section) of the convex portion 22 is substantially rectangular, the upper surface (the surface on the positive side in the z-axis direction) of the convex portion 22 corresponds to the tip of the convex portion 22.

  Specifically, as shown in FIG. 4, a rounded corner portion 24 is provided at the tip of the convex portion 22 as an example of a round shape. Thereby, dust, dirt, etc. become difficult to get caught, and antifouling property can be improved.

  The corner 24 is, for example, a curved surface having a radius of 0.1 times or less the height h1 of the convex portion 22. For example, when the height h1 of the convex portion 22 is 40 μm, the corner portion 24 can be a curved surface having a radius of 4 μm. In addition, the magnitude | size and shape of the corner | angular part 24 are not limited to these. In addition, the corner portion 24 may be an inclined surface that is inclined with respect to the upper surface of the convex portion 22. For example, the angle formed by the inclined surface and the upper surface may be greater than 90 °.

  In the present embodiment, a taper is provided at the base of the convex portion 22. The root of the convex portion 22 corresponds to the bottom of the concave portion 23. Thereby, it is possible to make it difficult for dirt to accumulate at the base of the convex portion 22. Moreover, the intensity | strength of the convex part 22 can be raised.

  Specifically, as shown in FIG. 4, a taper portion 25 is provided at the base of the convex portion 22. The tapered portion 25 is an inclined surface that is inclined with respect to the side surface of the convex portion 22 and the bottom surface of the concave portion 23. The inclined surface may be a flat surface or a curved surface. In the case of a curved surface, for example, the curved surface is convex toward the bottom of the recess 23. The width d3 and the height h3 of the taper portion 25 are each 0.134 times or less of the width d2 of the recess 23.

  As a result, as shown in FIG. 5, even if the water 91 enters the recess 23, the water 91 does not contact the tapered portion 25 due to the surface tension. FIG. 5 is a cross-sectional view for explaining the relationship between the tapered portion 25 provided at the base of the convex portion 22 of the water repellent film 1 according to the present embodiment and the water 91. FIG. 5 shows the same cross section as FIG. Since the taper part 25 and the water 91 do not contact, the intensity | strength of the convex part 22 can be raised, without impairing water repellency.

  In FIG.4 and FIG.5, the case where the contact angle with respect to the water 91 of the material of the convex part 22 is 120 degrees is assumed. For example, when the width d2 of the concave portion 23 is 40 μm, the width d3 and the height h3 of the tapered portion 25 are each 5.36 μm or less.

[Relationship between hyphae and recess width]
Here, the relationship between the mycelium of filamentous fungi such as mold and the width of the recess 23 will be described with reference to FIG. FIG. 6 is a top view for explaining the relationship between the width d2 of the recess 23 and the mycelium 95 according to the present embodiment.

  In the present embodiment, the width d <b> 2 of the concave portion 23, i.e., the distance between two adjacent convex portions 22 may be three times or less the thickness D of the mycelium 95. For example, the mycelium 95 is a mycelium such as cloud sporium or penicillium, and the thickness D is 1 μm to 3 μm. For this reason, the width d2 can be 9 μm or less. As an example, the width d2 is 7 μm or less.

  As a result, the mycelium 95 is less likely to enter the recess 23, and even if it enters, it is difficult to grow in the direction perpendicular to the recess 23. . For this reason, the mycelium 95 becomes easy to peel, and the antifouling property of the water repellent film 1 can be improved.

[Production method]
Then, the manufacturing method of the water repellent film 1 which concerns on this Embodiment is demonstrated using FIG. FIG. 7 is a process cross-sectional view illustrating the method of manufacturing the water repellent film 1 according to the present embodiment.

  The water-repellent film 1 is manufactured using a transfer technique using, for example, a nanoimprint apparatus or a roll-to-roll gravure printing apparatus.

  First, as shown to (a) of FIG. 7, the base material 10 is prepared. Next, as illustrated in FIG. 7B, an ultraviolet curable resin 20 a is applied to the main surface of the substrate 10 using the discharge device 30. Thereby, the resin layer 20 before curing having a substantially uniform film thickness (for example, 1 μm to 50 μm) is formed on the substrate 10. After film formation, the solvent component (solvent) contained in the resin layer 20 is volatilized using a hot plate or the like.

  Next, as shown in FIG. 7C, a mold (mold) 31 having irregularities of a predetermined shape is pressed against the resin layer 20 before curing. The mold 31 is formed using a metal material such as silicon, nickel, copper, or a resin material. The mold 31 is provided with irregularities having a shape obtained by inverting the irregular structure 21 and is surface-treated with a release agent.

  As shown in FIG. 7D, while pressing the mold 31 against the resin layer 20, the ultraviolet light source (UV light) is irradiated to the portion where the resin layer 20 and the mold 31 are in contact with each other. Thereby, the uneven | corrugated shape of the mold 31 is transcribe | transferred to the resin layer 20 before hardening, and the uneven structure 21 is formed.

  By peeling the mold 31, the water-repellent film 1 having the concavo-convex structure 21 is manufactured as shown in FIG.

  Note that the surface of the uneven structure 21 may be coated with fluorine. As a fluorine coating method, a dip method, a spray method, a vapor deposition method, or the like is appropriately selected according to the target film quality. Further, the uneven structure 21 may be formed by injection molding or the like.

[Effects, etc.]
Here, in order to explain the effect of the water-repellent film 1 according to the present embodiment in an easy-to-understand manner, an example of a concavo-convex structure according to a comparative example having no line and space shape is shown in FIG. FIG. 8 is a top view for explaining problems of the uneven structure 21x according to the comparative example. In the concavo-convex structure 21x according to the comparative example, as shown in FIG. 8, a plurality of columnar convex portions 22x are arranged at each vertex of a triangular lattice (a part is shown by a regular triangle of a one-dot chain line).

  When the cleaning liquid 90x is poured on the surface of the concavo-convex structure 21x or the dirt is cleaned by rubbing with a sponge or the like, the flow of the cleaning liquid 90x or the dirt itself is blocked by the convex portions 22x, so that the dirt is difficult to wash off. In addition, dust and dirt are likely to be accumulated in the four corner regions 92x of the cylindrical convex portion 22x.

  On the other hand, the water repellent film 1 according to the present embodiment includes a base material 10 and a resin layer 20 provided on the base material 10, and the resin layer 20 includes a plurality of line-shaped convex portions 22. The at least one of the plurality of convex portions 22 is periodically bent in a plan view.

  In the concavo-convex structure 21, the plurality of convex portions 22 support the water 91, thereby preventing the water 91 from reaching (contacting) the bottom of the concave portion 23. Thereby, since the uneven structure 21 has water slidability and water 91 easily flows on the surface of the water repellent film 1, adhesion of dirt such as a scale component can be suppressed and antifouling property can be improved.

  Moreover, since the concavo-convex structure 21 has a line-and-space shape, as shown in FIG. 2, the cleaning liquid 90 and dirt can be poured in the direction (y-axis direction) in which the convex portion 22 (line) extends. That is, when cleaning is performed by flowing the cleaning liquid 90 or rubbing with a sponge, the cleaning can be performed without being blocked by the convex portion 22.

  Moreover, since the convex part 22 is bent periodically, intensity | strength can be raised compared with a linear convex part. For this reason, for example, even when a force is applied to the convex portion 22 from the outside, such as when the user rubs the surface of the concave-convex structure 21 with a sponge or the like, the concave-convex structure 21 is not easily broken and maintains water repellency. can do. Since the water repellency can be maintained, the adhesion of dirt such as scale components can be suppressed, so that the antifouling property can be improved.

  For example, at least one of the plurality of convex portions 22 has a wave shape that is periodically bent with a substantially constant amplitude in a plan view.

  Thus, the bending amplitude of the convex portion 22 is substantially constant, and there is no portion that is locally bent large or small. Therefore, the water slidability within the surface of the water-repellent film 1 can be made substantially uniform, and it becomes difficult for water to accumulate on the surface, so that adhesion of dirt can be suppressed and the attached dirt can be easily washed off. Become.

  Further, for example, when the wave-shaped convex portion 22 is viewed in plan, two tangents TL1 and TL2 at two inflection points IP1 and IP2 adjacent to each other on the reference line BL where the displacement of the periodic bending becomes 0 are obtained. The formed angle θ is 90 ° or more and less than 180 °.

  Thereby, bending of the convex part 22 becomes smooth and the planar view shape of the convex part 22 approaches a linear shape more. Therefore, since it becomes difficult to form a liquid pool in the concavo-convex structure 21, the adhesion of dirt can be suppressed, and the attached dirt can be easily washed away.

  Further, for example, a linear space 23 a having a predetermined width parallel to the reference line BL is included between two adjacent convex portions 22 of the plurality of convex portions 22.

  Accordingly, the space 23a is provided, so that the cleaning liquid 90 and the dirt itself can flow more straightly as shown in FIG. That is, the antifouling property of the concavo-convex structure 21 can be enhanced, and the attached dirt can be easily washed away.

  For example, the plurality of convex portions 22 have substantially the same shape.

  Thereby, in-plane water repellency and water slidability can be made substantially uniform.

  Further, for example, in a plan view, the total area of the plurality of convex portions 22 is 50% or less of the total area of the concavo-convex structure 21.

  Thereby, since the area of the convex part 22 becomes small, the contact area of the uneven structure 21 and water becomes small. Therefore, the water repellency and water slidability of the concavo-convex structure 21 can be increased, and thus the antifouling property of the water repellent film 1 can be increased.

  Further, for example, a taper (specifically, a taper portion 25) is provided at the base of the convex portion 22.

  As a result, dirt or the like hardly accumulates at the base of the convex portion 22 and the dirt attached to the base of the convex portion 22 is easily removed. Moreover, the intensity | strength of the convex part 22 can be raised.

  In addition, for example, a radius (specifically, a corner portion 24) is provided at the tip of the convex portion 22.

  Thereby, since dust, dirt, etc. become difficult to get caught in the tip of convex part 22, antifouling property of water repellent film 1 can be improved.

  Further, for example, a distance d2 between two adjacent convex portions 22 of the plurality of convex portions 22 is not more than three times the thickness D of the mycelia.

  As a result, the mycelium 95 is less likely to enter the recess 23, and even if it enters, it is difficult to grow in the direction perpendicular to the recess 23. . For this reason, the mycelium 95 becomes easy to peel, and the antifouling property of the water repellent film 1 can be improved.

(Modification 1)
Subsequently, Modification 1 of the embodiment will be described. Note that the water-repellent film according to this modification is different only in the shape of the concavo-convex structure, and the other points are the same as those in the embodiment. Therefore, in the following description, the shape of the concavo-convex structure will be mainly described, and description of the same points as in the embodiment will be omitted or simplified. The same applies to Modification 2 described later.

  FIG. 9 is a top view of the concavo-convex structure 121 of the water-repellent film according to this modification. As shown in FIG. 9, the concavo-convex structure 121 according to this modification is a fine concavo-convex structure having a line-and-space shape, and specifically includes a plurality of convex portions 122 and a plurality of concave portions (grooves) 123. Have.

  In the water repellent film according to this modification, the angle θ formed by the two tangents TL1 and TL2 at the two adjacent inflection points IP1 and IP2 on the reference line BL of each of the plurality of convex portions 122 is less than 90 °. is there. Specifically, as shown in FIG. 9, the plan view shape of the convex portion 122 has a wave shape in which vertices (indicated by black circles) of a triangular lattice are continuously connected. In this case, the angle θ is about 60 °.

  In the present modification, the sliding force is slightly impaired as compared with the embodiment because the angle θ is small, but the strength of the convex portion 122 can be further increased. Therefore, the concavo-convex structure 121 is not easily destroyed, and the water repellency can be maintained for a long time.

  In the present modification, when the angle θ is too small, a liquid pool is formed at the bent portion of the convex portion 122, and dirt may be easily collected. Therefore, the angle θ is, for example, 45 ° or more, preferably 60 ° or more.

(Modification 2)
Then, the modification 2 of embodiment is demonstrated.

  FIG. 10 is a top view of the concavo-convex structure 221 of the water repellent film according to this modification. As shown in FIG. 10, the concavo-convex structure 221 is a fine concavo-convex structure having a line-and-space shape, and specifically, a plurality of first convex portions 222a, a plurality of second convex portions 222b, and a plurality of first convex portions. It has 1 recessed part 223a and several 2nd recessed part 223b.

  The plurality of first protrusions 222a and the plurality of second protrusions 222b are alternately arranged one by one. The first convex portion 222a and the second convex portion 222b are different in plan view shape. The 1st convex part 222a and the 2nd convex part 222b are equivalent to the line of a line and space shape.

  As shown in FIG. 10, the first protrusion 222a has a smaller bending amplitude than the second protrusion 222b. That is, the 1st convex part 222a is bent more gently than the 2nd convex part 222b. For example, in the 1st convex part 222a, the angle (refer FIG. 3) which two tangents in two adjacent inflection points on a reference line make is 90 degrees or more and less than 180 degrees. On the other hand, in the 2nd convex part 222b, the angle which the two tangents in two adjacent inflection points on a reference line make is less than 90 degrees.

  The plurality of first recesses 223a and the plurality of second recesses 223b are alternately arranged one by one. The 1st recessed part 223a and the 2nd recessed part 223b are equivalent to the space of a line and space shape.

  In the present modification, the first convex portion 222a and the second convex portion 222b have different planar shapes, and therefore the first concave portion 223a and the second concave portion 223b have different shapes. Here, the first concave portion 223a corresponds to a space between the first convex portion 222a and the second convex portion 222b adjacent on the positive side in the x-axis direction of the first convex portion 222a. The second concave portion 223b corresponds to a space between the second convex portion 222b and the first convex portion 222a adjacent on the positive side in the x-axis direction of the second convex portion 222b. The plan view shape of the first recess 223a is a shape obtained by inverting the plan view shape of the second recess 223b around the y-axis direction.

  As shown in FIG. 10, the width of the first recess 223a changes periodically. Similarly, the width of the second recess 223b changes periodically. In this modification, the maximum width Dmax of the first recess 223a and the maximum width Dmax of the second recess 223b are substantially equal.

  As described above, in the water-repellent film according to the present modification, for example, the plurality of protrusions includes one or more first protrusions 222a and one or more first protrusions 222a having different shapes. 2 convex portions 222b are included, and one or more first convex portions 222a and one or more second convex portions 222b are alternately arranged.

  As shown in the above embodiment, the first convex portion 222a and the second convex portion 222b support the water so that the water does not reach the bottom of the concave portion, thereby providing the water-sliding property of the concave-convex structure 221. Can do. For this purpose, a protrusion having a sufficient height relative to the width of the first recess 223a and the second recess 223b is required. For example, the height of the convex portion needs to be increased as the width of the concave portion increases.

  Here, for example, in the water-repellent film according to this modification, the maximum distance Dmax between two adjacent convex portions of the plurality of convex portions is substantially equal between the convex portions.

  Thereby, since the maximum distance between convex parts becomes substantially equal, the height of the convex part required in order to prevent water from reaching the bottom of a recessed part can be made substantially equal. Therefore, the design and formation of the uneven structure 221 is facilitated. Moreover, since the height of the upper surface of the convex part of the concavo-convex structure 221 is uniform, it becomes difficult to apply a pressure from the lateral direction to the convex part, and the destruction of the convex part can be suppressed. Thereby, the water repellent film can maintain water repellency and water slidability for a long time.

(Other)
As mentioned above, although the water-repellent film which concerns on this invention was demonstrated based on embodiment and its modification, this invention is not limited to said embodiment etc.

  For example, in the above-described embodiment, the example in which all the convex portions 22 included in the concavo-convex structure 21 are periodically bent in a plan view is shown, but the present invention is not limited thereto. The convex portion 22 of the concavo-convex structure 21 may include a linear convex portion. That is, at least one of the plurality of convex portions 22 included in the concavo-convex structure 21 may be bent periodically in plan view.

  For example, in the above-described embodiment, the example in which the bending amplitude of the convex portion 22 is substantially constant has been described, but the present invention is not limited thereto. The amplitude may be random, or may vary depending on the period, such as gradual increase or decrease.

  For example, in the above-described embodiment, an example in which the cross-sectional shape of the convex portion 22 is substantially rectangular has been described, but the cross-sectional shape of the convex portion 22 may be a trapezoid or a triangle. At this time, R may be provided at the corners of the trapezoid or the triangle.

  In addition, it is realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, and forms obtained by making various modifications conceived by those skilled in the art to each embodiment. Forms are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 Water repellent film 10 Base material 20 Resin layer 21, 121, 221 Uneven structure 22, 122 Convex part 23, 123 Concave part 23a Space 24 Corner part (R)
25 Tapered portion 95 Mycelia 222a First convex portion 222b Second convex portion BL Reference lines IP1, IP2 Inflection points TL1, TL2 Tangent

Claims (11)

A substrate;
A resin layer provided on the substrate,
The resin layer has a line-and-space uneven structure having a plurality of line-shaped protrusions,
At least one of the plurality of convex portions is a water repellent film that is periodically bent in a plan view. The water repellent film according to claim 1, wherein at least one of the plurality of convex portions has a wave shape that is periodically bent with a substantially constant amplitude in a plan view. When the corrugated convex portion is viewed in plan, an angle formed by two tangents at two adjacent inflection points on the reference line on which the cyclic bending displacement is 0 is 90 ° or more and less than 180 °. The water repellent film according to claim 2. The water repellent film according to claim 3, wherein a linear space having a predetermined width parallel to the reference line is included between two adjacent convex portions of the plurality of convex portions. The water repellent film according to any one of claims 1 to 4, wherein the plurality of convex portions have substantially the same shape. The plurality of protrusions include one or more first protrusions and one or more second protrusions having a shape different from that of the one or more first protrusions,
The water repellent film according to claim 1, wherein the one or more first protrusions and the one or more second protrusions are alternately arranged. The water repellent film according to any one of claims 1 to 6, wherein, in a plan view, the total area of the plurality of convex portions is 50% or less of the total area of the concavo-convex structure. The water repellent film according to any one of claims 1 to 7, wherein a maximum distance between two adjacent convex portions of the plurality of convex portions is substantially equal to each other between the convex portions. The water repellent film according to any one of claims 1 to 8, wherein a taper is provided at a base of the convex portion. The water repellent film according to any one of claims 1 to 9, wherein a radius is provided at a tip of the convex portion. The water repellent film according to any one of claims 1 to 10, wherein a distance between two adjacent convex portions of the plurality of convex portions is three times or less the thickness of the mycelium.

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