Molded body, manufacturing method of molded body, and water-related equipment

Abstract

To provide a molded product with higher quality liquid repellent property.SOLUTION: A molded product (resin molded product) 1 includes a concave-convex structure surface 30 in which a plurality of concave portions 32 and a plurality of convex portions 31 are alternately and repeatedly arranged along a predetermined direction and are arranged in a planar shape to exhibit liquid repellent property. In the concave-convex structure surface 30, at least one hole 311 has a tip surface on which at least one convex portion 31 is formed. A coating material 39 that is different from a material constituting the convex portion 31 is coated around the hole 311.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a molded body, a manufacturing method for a molded body, and a water-related device. [Background technology]

[0002] For example, in a resin molded body, which is one type of molded body, a resin molded body is known in which fine irregularities are formed on one side of a substrate, and a fluorine-based lubricant is layered on one side of the substrate to cover the irregularities, thereby exhibiting liquid repellency (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6357855 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the above-mentioned resin molded article, the liquid repellency is exhibited depending only on the chemical properties of the lubricant, but there is a demand for higher quality in terms of liquid repellency.

[0005] Therefore, an object of the present invention is to provide a molded article or the like having higher quality in terms of liquid repellency. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, according to one embodiment of the present invention, a molded body has a concave-convex structure surface in which a plurality of concave portions and a plurality of convex portions are arranged alternately and repeatedly along a predetermined direction and are arranged in a planar manner to exhibit liquid repellency, and in the concave-convex structure surface, at least one hole is formed in the tip surface of at least one convex portion, and a coating material of a different type from the material constituting the convex portions is applied around the hole.

[0007] In addition, according to a method for producing a molded body according to one aspect of the present invention, the method for producing the above-mentioned molded body includes forming a concave-convex structure surface by performing laser processing on the surface of a substrate.

[0008] A plumbing device according to one aspect of the present invention includes the above-described molded body. Effect of the Invention

[0009] According to the present invention, it is possible to provide a molded article having higher quality in terms of liquid repellency. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a system kitchen in which the resin molded article according to the first embodiment is used. [Diagram 2] FIG. 2 is a plan view showing a surface structure of a portion where a resin molded body is applied in the system kitchen according to the first embodiment. [Diagram 3] 3 is a cross-sectional view taken along the line III-III in FIG. 2. FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a state in which a droplet has entered between a pair of adjacent protrusions according to the first embodiment. [Diagram 5] FIG. 5 is a plan view showing the concave-convex structure surface according to the second embodiment. [Figure 6] FIG. 6 is an enlarged cross-sectional view showing an outer circumferential surface of a protrusion according to the third embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing an outer circumferential surface of a protrusion according to the fifth embodiment. [Figure 8] FIG. 8 is a schematic diagram showing convex portions and concave portions when the holes are not filled with the coating material in the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the resin molded body according to the embodiment of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0012] In addition, each figure is a schematic diagram and is not necessarily illustrated precisely. Therefore, for example, the scales in each figure do not necessarily match. In addition, in each figure, substantially the same configurations are given the same reference numerals, and duplicated explanations are omitted or simplified.

[0013] Furthermore, in this specification, terms indicating the relationship between elements, such as parallel or perpendicular, terms indicating the shape of elements, such as square or rectangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0014] (Embodiment 1) [Resin molding] First, an application example of the resin molded body 1 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view showing a system kitchen 100 in which the resin molded body 1 according to the first embodiment is used.

[0015] As shown in FIG. 1, a system kitchen 100 is an example of plumbing equipment, and includes a gas range 110, a sink 120, and a faucet .

[0016] Fig. 2 is a plan view showing the surface structure of a portion where resin molded body 1 is applied in system kitchen 100 according to embodiment 1. Fig. 3 is a cross-sectional view of a cut surface including line III-III in Fig. 2. Resin molded body 1 is applied to at least a portion of the outer surface of system kitchen 100.

[0017] 2 and 3, the surface of the resin molded body 1 is a concave-convex structure surface 30 having a so-called reentrant structure. The concave-convex structure surface 30 has a plurality of convex portions 31 and a plurality of concave portions 32 arranged alternately and repeatedly along a predetermined direction, and these are arranged in a plane to exhibit liquid repellency.

[0018] Specifically, the uneven structure surface 30 has a plurality of convex portions 31 arranged in a matrix in a plan view. The convex portions 31 are substantially square in a plan view. Each of the convex portions 31 has a substantially identical shape. The convex portions 31 have a shape in which the tip portion is enlarged compared to the base portion. Specifically, the size of the convex portion 31 in an axial view is larger at the tip portion than at the base portion of the convex portion 31. For example, the convex portion 31 is formed in an inverted square truncated pyramid shape. A plurality of holes 311 are provided in the tip surface of the convex portion 31, and each hole 311 extends along the axial direction of the convex portion 31, and is open at the tip end side and closed at the base end side. The plan view shapes of the holes 311 may be the same or different. Examples of the plan view shapes of the holes 311 include a circular shape, an oval shape, an elliptical shape, and a polygonal shape.

[0019] Moreover, a coating material 39 of a different type from the material constituting the protrusion 31 is directly laminated on the tip surface of the protrusion 31. The coating material 39 is a liquid-repellent material that can exhibit liquid repellency (water repellency) due to its chemical properties alone. Examples of liquid-repellent materials include lubricants, surfactants, liquid repellents, gel agents, and self-repairing materials. The coating material 39 is filled in each hole 311. This enhances the unity between the protrusion 31 and the coating material 39, and the coating material 39 is stably held by the protrusion 31 and is less likely to peel off. The coating material 39 may be filled only on the tip side of the hole 311, but to exhibit higher retention, it is preferable that the coating material 39 is filled in the entire hole 311. Furthermore, if the multiple holes 311 are evenly distributed and arranged on the tip surface of one protrusion 31, for example in a matrix shape, the coating material 39 can be more stably held. Even if only one hole 311 is provided for the protrusion 31, as long as the hole 311 is filled with the coating material 39, the retention can be improved.

[0020] The portions between the multiple protruding portions 31 in the predetermined direction form recessed portions 32. The recessed portion 32 is continuous in a lattice shape when viewed overall and can therefore be regarded as one recessed portion 32, but when viewed only in the predetermined direction, it is divided into individual protruding portions 31 and can therefore be regarded as multiple recessed portions 32. In other words, the multiple recessed portions 32 and the multiple protruding portions 31 are alternately arranged at a predetermined pitch both in the vertical direction and in the horizontal direction.

[0021] As shown in FIG. 3, the sum of the width f1 of the convex portion 31 in a predetermined direction and the width f2 of the concave portion 32 is the predetermined pitch (τ=f1+f2). The width f1 is the width of the tip of the convex portion 31. Therefore, the width of the hole 311 formed in the tip surface of the convex portion 31 is smaller than the width f1. The width f2 is the width of the tip of the concave portion 32, that is, the width between the tips of a pair of adjacent convex portions 31. The widths f1 and f2 are on the order of nanometers or micrometers. The concave-convex structure surface 30 can be made a water-repellent surface by setting the predetermined pitch τ and the widths f1 and f2 to satisfy a certain relationship. For example, the concave-convex structure surface 30 can be made a water-repellent surface by satisfying a relationship in which θ' in formula (1) is the value of the water-repellent region.

[0022] cosθ'=-1+1 / D{(π-θ)cosθ+sinθ}···(1)

[0023] In formula (1), D=τ / f1. θ is the pure water static contact angle of the substrate itself that constitutes the concave-convex structure surface 30. θ' is the pure water static contact angle of the concave-convex structure surface 30 itself. In this embodiment, a simulation is performed using formula (1) to determine the width f1 of the convex portion 31 and the width f2 of the concave-convex portion 32 so that θ' exceeds 120°. As long as this relationship is satisfied, the concave-convex structure may be non-uniform in the concave-convex structure surface 30. For example, the concave-convex structure surface 30 includes a first region 30a and a pair of second regions 30b having a predetermined pitch τ different from each other. The pair of second regions 30b are arranged so as to sandwich the first region 30a in the horizontal direction. The first region 30a and the second region 30b are regions whose pure water static contact angles differ from each other by 5° or more. In this embodiment, the width f1 of the convex portion 31 and the width f2 of the concave portion 32 are determined based on the formula (1) so that the pure water static contact angle of the first region 30a is 121°. On the other hand, the width f1 of the convex portion 31 and the width f2 of the concave portion 32 are determined based on the formula (1) so that the pure water static contact angle of the second region 30b is 150°. In this way, since the pure water static contact angles of the first region 30a and the second region 30b are different, the liquid droplets can be collected from the second region 30b toward the first region 30a, which has a relatively low pure water static contact angle. If multiple liquid droplets are collected and integrated, their weight also increases, making it easier for the liquid droplets to slide down, and the liquid repellency on the concave-convex structure surface 30 can be improved.

[0024] Here, if the difference in the pure water static contact angle between the first region 30a and the second region 30b is 5° or more, it is possible to smoothly collect droplets from the second region 30b, which has a higher pure water static contact angle, to the first region 30a, which has a lower pure water static contact angle. In particular, in this embodiment, the difference in the pure water static contact angle between the first region 30a and the second region 30b is 30°, so that it is possible to more smoothly collect droplets toward the first region 30a.

[0025] As described above, each of the protrusions 31 has an inverted square pyramid shape with the tip being larger than the base. Therefore, the outer peripheral surface of each of the protrusions 31 has a shape that widens toward the tip. In other words, the outer peripheral surface of the protrusions 31 has a shape in which the distance from the central axis of the protrusion 31 to the edge gradually increases from the base to the tip.

[0026] FIG. 4 is a cross-sectional view showing a state where a liquid droplet L has entered between a pair of adjacent protrusions 31 according to the first embodiment. As shown in FIG. 4, when the liquid droplet L enters between a pair of adjacent protrusions 31, the liquid droplet L in the recess 32 is projected toward the bottom surface of the recess 32 due to surface tension. In this state, a force F along the tangent line of the surface of the liquid droplet L is generated on the outer circumferential surface of the protrusion 31. Since this force F is a force toward the tip of the protrusion 31, the liquid droplet L in the recess 32 tries to move toward the tip of the protrusion 31 due to this force F. In other words, in order to prevent the liquid droplet L from falling further from the recess 32, it is necessary to withstand external factors such as external pressure and vibration, and high liquid repellency is maintained and exhibited.

[0027] In particular, in this embodiment, the tip surfaces of the projections 31 are entirely covered with the coating material 39. That is, in addition to the liquid repellency derived from the fine structure formed by the plurality of projections 31 and the plurality of recesses 32, the liquid repellency derived from the chemical properties of the coating material 39 is exerted. This makes it easier for the droplets L to move in a sliding manner on the tips of the projections 31, improving the liquid removal property.

[0028] [Method of manufacturing resin molded body] Next, a method for producing the resin molded body 1 will be described.

[0029] First, a flat substrate is prepared. This substrate may be made of any resin as long as it can be laser processed. Examples of resins that can be laser processed include thermoplastic resins. Examples of thermoplastic resins include polyolefin resins, polyamide resins, elastomer resins (styrene resins, olefin resins, polyvinyl chloride (PVC) resins, urethane resins, ester resins, amide resins), polyester resins, engineering plastics, polyethylene, polypropylene, nylon resins, acrylonitrile-butadiene-styrene (ABS) resins, acrylic resins, ethylene acrylate resins, ethylene vinyl acetate resins, polystyrene resins, polyphenylene sulfide resins, polycarbonate resins, polyester elastomer resins, polyamide elastomer resins, liquid crystal polymers, polybutylene terephthalate resins, acetyl cellulose, polyvinyl acetate, and the like. One of these may be used alone, or a mixture of multiple resins in which these resins are the main components may be used.

[0030] The substrate may also contain a thermosetting resin. Examples of the thermosetting resin include epoxy resin, unsaturated polyester resin, vinyl ester resin, phenol resin, urethane resin, melamine resin, urea resin, maleimide resin, cyanate ester resin, alkyd resin, addition curing polyimide resin, and thermosetting acrylic resin. The thermosetting resin may contain only one of these, or may contain a mixture of multiple resins containing these resins as the main components. This can increase the heat resistance of the resin molded body 1.

[0031] In this way, the molded body is suitable for laser processing because it is the resin molded body 1. In particular, since the resin molded body 1 contains a thermosetting resin, the heat resistance of the resin molded body 1 can be improved.

[0032] Next, the surface of the base material is laser processed to form the uneven structure surface 30. Specifically, the surface of the base material is laser processed so that a plurality of recesses 32 and a plurality of protrusions 31 are alternately arranged in a plane at a predetermined pitch along a predetermined direction, thereby forming the uneven structure surface 30. A short pulse laser is irradiated onto the surface of the base material from a laser irradiation device that irradiates the laser. The pulse width of the short pulse laser is preferably nanoseconds or less. At this time, the laser processing is performed so that each protrusion 31 has an inverted square pyramid shape by adjusting parameters such as the laser output, spot diameter, direction of the optical axis, scanning speed, scanning direction, and pulse width. In addition, it is preferable that the laser processing is an ablation processing. If it is an ablation processing, it is possible to suppress thermal damage to the processing object. In addition, it is possible to sharpen the cross-sectional shape of the protrusions 31 and the recesses 32.

[0033] Thereafter, the tip surface of each protrusion 31 is subjected to laser processing with an even smaller spot diameter to form a hole 311 in the tip surface. In this laser processing, the parameters are also adjusted so that a hole 311 of an appropriate size and depth is formed. It is preferable that the laser processing for forming the hole 311 is also an ablation processing.

[0034] After forming the holes 311 for each of the protrusions 31, the coating material 39 is applied onto the concave-convex structure surface 30. At this time, the coating material 39 enters and fills each of the holes 311 by capillary action. Since the coating material 39 is applied with a thickness that is very small compared to the height of the protrusions 31, even if the coating material 39 drips into the recesses 32, it does not completely fill the recesses 32. In other words, the outer circumferential surface of the protrusions 31 remains exposed. Note that if the coating material 39 is applied while each recess 32 is blocked with a mask or the like, and then the mask is removed, it is possible to reduce the amount of coating material 39 that enters the recesses 32.

[0035] [Effects, etc.] As described above, in the concave-convex structure surface 30, at least one hole 311 is formed in the tip surface of the convex portion 31, and the coating material 39 is applied around the hole 311. Therefore, in addition to the liquid repellency derived from the fine structure formed by the multiple convex portions 31 and the multiple concave portions 32, liquid repellency derived from the chemical properties of the coating material 39 is exhibited. In this way, the liquid repellency derived from the fine structure and the liquid repellency derived from the chemical properties are exhibited in a composite manner on the concave-convex structure surface 30, so that the liquid repellency on the concave-convex structure surface 30 can be enhanced.

[0036] In addition, since the coating material 39 is filled in the holes 311, it is difficult to peel off. Therefore, the composite liquid repellency can be stably exhibited for a long period of time. As a result, it is possible to provide the resin molded body 1 with high quality in terms of liquid repellency.

[0037] Furthermore, since such a resin molded article 1 is applied to a plumbing device (system kitchen 100), it is also possible to improve the liquid repellency of the plumbing device.

[0038] In addition, since the tip of the protrusion 31 is enlarged more than the base, it is possible to make it difficult for liquid to enter the recess 32. Therefore, it is possible to enhance the liquid repellency derived from the fine structure.

[0039] In addition, the outer peripheral surface of the protrusion 31 has a shape in which the distance from the central axis of the protrusion 31 to the edge gradually increases from the base to the tip. Therefore, a force F toward the tip of the protrusion 31 can be applied to the droplet L that has entered the recess 32. This force F causes the droplet L in the recess 32 to move toward the tip of the protrusion 31. In other words, the droplet L tries to get out of the recess 32, so high liquid repellency is maintained.

[0040] Here, the reality is that a pure water static contact angle of more than 120° cannot be achieved by chemical properties. For example, even a fluororesin surface having a trifluoromethyl group, which has the highest pure water contact angle, cannot achieve a pure water static contact angle of more than 120°. However, it can be achieved by fine structure. That is, the fine structure of the concave-convex structure surface 30 can achieve a pure water static contact angle of more than 120° in the first region 30a and the second region 30b. If the pure water static contact angle exceeds 120°, water is easily repelled. Therefore, it is possible to achieve high water repellency (liquid repellency) that cannot be achieved by chemical properties alone.

[0041] In addition, since the first region 30a and the second region 30b having different predetermined pitches are provided in the concave-convex structure surface 30, the static contact angle of pure water between the first region 30a and the second region 30b can be made different. This allows droplets to be collected from the second region 30b toward the first region 30a, which has a relatively low static contact angle of pure water. If multiple droplets are collected and integrated, their weight increases and the droplets become more likely to slide down, thereby improving the liquid repellency on the concave-convex structure surface 30.

[0042] In addition, since the difference in the static contact angle of pure water between the first region 30a and the second region 30b is 5° or more, this difference allows droplets to be more smoothly collected from the second region 30b toward the first region 30a, which has a relatively low static contact angle of pure water.

[0043] Furthermore, since the concave-convex structure surface 30 of the resin molded body 1 is formed by laser processing, the concave-convex structure surface 30 can be formed without using organic materials that are likely to have an adverse effect on the environment.

[0044] In addition, since the holes 311 are formed by performing laser processing on the tip surfaces of the protrusions 31, the concave-convex structure surface 30 and the holes 311 can be formed by the same processing method, thereby making it possible to improve manufacturing efficiency.

[0045] In addition, since the laser processing is an ablation process, it is possible to make the cross-sectional shapes of the convex portions 31 and the concave portions 32 sharp. In other words, the outer peripheral surface of the convex portion 31 can be made to have a smooth shape, and the force F toward the tip portion of the convex portion 31 can be more reliably applied to the liquid droplet L that has entered between a pair of adjacent convex portions 31. This force F can more reliably cause the liquid droplet L to escape from the concave portions 32, thereby exhibiting high liquid repellency.

[0046] (Embodiment 2) In the first embodiment, a concave-convex structure surface 30 in which a plurality of protrusions 31 are arranged in a matrix is ​​exemplified. In the second embodiment, a concave-convex structure surface 30A in which a plurality of protrusions 31 are arranged in a striped pattern is exemplified. In the following description, the same reference numerals may be used to designate parts equivalent to those in the first embodiment, and the description thereof may be omitted.

[0047] FIG. 5 is a plan view showing the concave-convex structure surface 30A according to the second embodiment. Specifically, FIG. 5 is a view corresponding to FIG. 2. As shown in FIG. 5, each of the convex portions 31a and each of the concave portions 32a are formed in a linear shape. Each of the convex portions 31a is formed in a trapezoid shape with a tip portion enlarged from a base portion when viewed in the longitudinal direction. The multiple convex portions 31a and the multiple concave portions 32a are repeatedly and alternately arranged at a predetermined pitch. Even in this case, it is possible to make the concave-convex structure surface 30A a liquid-repellent surface as long as the above-mentioned conditions are satisfied. Note that the concave portions 32a and the convex portions 31a may have any shape in plan view as long as they are repeatedly and alternately arranged at a predetermined pitch.

[0048] (Embodiment 3) In the first embodiment, the convex portion 31 is shaped like a square pyramid. However, the outer circumferential surface of the convex portion may have a shape in which the distance from the central axis of the convex portion to the edge gradually increases from the base to the tip. In the third embodiment, as an example, the outer circumferential surface of the convex portion has a convex curved shape.

[0049] Fig. 6 is an enlarged cross-sectional view of the outer circumferential surface of the convex portion 31b according to the third embodiment. Specifically, Fig. 6 is a view corresponding to Fig. 4. As shown in Fig. 6, the outer circumferential surface of the convex portion 31b has a convex curved shape that protrudes outward. In this case, as shown in Fig. 6, when a liquid droplet L enters between a pair of adjacent convex portions 31b, the liquid droplet L in the concave portion 32b protrudes toward the bottom surface of the concave portion 32b due to surface tension. A force F is generated in the liquid droplet L along the tangent line of the surface of the liquid droplet L on the outer circumferential surface of the convex portion 31b.

[0050] Here, FIG. 6 illustrates multiple surface positions of the droplet L for each degree of progression into the recess 32b. The surface position that has progressed the furthest into the recess 32b is the droplet L, and as the degree of progression progresses, it becomes droplet L1, droplet L2. As shown in FIG. 6, since the outer peripheral surface of the convex portion 31b has a convex curved shape, the force F varies so as to incline toward the tip of the convex portion 31b as the droplets L, L1, and L2 progress into the recess 32b. In other words, the more the droplets L, L1, and L2 try to enter the recess 32b, the more the force F inclined toward the tip of the convex portion 31b acts on the droplets L, L1, and L2, so that the droplets L, L1, and L2 try to move toward the tip of the convex portion 31b. As a result, the droplets L, L1, and L2 are more likely to come out of the recess 32b, and thus high liquid repellency is exhibited.

[0051] If the outer circumferential surface of the protrusion 31b has a spherical shape, the above-mentioned fluctuation of the force F can be made more noticeable, which is preferable.

[0052] (Embodiment 4) In the first embodiment, the concave-convex structure surface 30 has an area (first area 30a, second area 30b) where the pure water static contact angle exceeds 120°. However, an area where the oleic acid static contact angle is 90° or more may be provided in the concave-convex structure surface 30. In this case, if θ is the oleic acid static contact angle of the substrate itself that constitutes the concave-convex structure surface 30 in the above formula (1), θ' is the oleic acid static contact angle of the concave-convex structure surface 30 itself. By performing a simulation using this formula (1), the width f1 of the convex portion 31 and the width f2 of the concave-convex structure surface 32 where the oleic acid static contact angle is 90° or more are determined. As a result, the fine structure of the concave-convex structure surface 30 exerts oil repellency (liquid repellency). In this case, if the coating material 39 is an oil repellent material, the oil repellency derived from the fine structure and the oil repellency derived from the chemical properties are exerted in a composite manner on the concave-convex structure surface 30, so that the oil repellency on the concave-convex structure surface 30 can be enhanced.

[0053] Depending on the determined values ​​of the width f1 of the convex portion 31 and the width f2 of the concave portion 32, it is also possible to form a region in which the static contact angle of oleic acid is 90° or more and the static contact angle of pure water is 120° or more within one region. In this case, both water repellency and oil repellency can be exhibited within the one region. As the coating material 39, a single material having water repellency and oil repellency may be used, or a water repellent material and an oil repellent material may be dispersed and filled into each hole 311.

[0054] (Embodiment 5) In the above embodiment, the case where the tip surface of the convex portion 31 is entirely covered with the coating material 39 has been exemplified. However, only a part of the tip surface of the convex portion 31 may be covered with the coating material 39. FIG. 7 is a cross-sectional view showing an enlarged outer circumferential surface of the convex portion 31c according to the fifth embodiment. Specifically, FIG. 7 is a view corresponding to FIG. 3. As shown in FIG. 7, the tip surface of the convex portion 31c is covered with the coating material 39 while avoiding the hole 311. In other words, the coating material 39 is continuously applied around the hole 311. In this way, if only a part of the tip surface of the convex portion 31c is covered with the coating material 39, in addition to the liquid repellency derived from the fine structure formed by the multiple convex portions 31 and the multiple concave portions 32, the liquid repellency derived from the chemical properties of the coating material 39 can be exhibited to a certain extent.

[0055] In addition, contrary to the form shown in Figure 7, a form in which only the coating material 39 filled in the hole 311 covers the tip surface of the convex portion 31 may also be included in the form in which the coating material 39 covers the periphery of the hole 311.

[0056] 8 is a schematic diagram showing the convex portion 31 and the concave portion 32 in the case where the hole 311 is not filled with the coating material 39 in the fifth embodiment. In this case, the convex portion 31 is illustrated as having a cylindrical or polygonal columnar shape. In the case where the hole 311 is not filled with the coating material 39, the following formula (2) is applied instead of the above formula (1).

[0057] cosθ'=-1+f SL (R f cosθ+1) (2)

[0058] Here, R f is synonymous with a function indicating the degree of surface roughness of the tip surface of the protrusion 31, and is a value of 1 or more. SL is the ratio of the surface area of ​​the solid constituting the protrusion 31. f1=R f f SL θ is the pure water static contact angle of the solid constituting the protrusion 31.

[0059] (others) Although the resin molded article according to the present invention has been described based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments.

[0060] For example, in the above-mentioned first embodiment, the case where all of the multiple protrusions 31 have the holes 311 and the coating material 39 has been exemplified, but it is sufficient that at least one of the protrusions 31 has the holes 311 and the coating material 39. However, if a certain level of improvement in liquid repellency is required, it is preferable that more than half of the multiple protrusions 31 have the holes 311 and the coating material 39.

[0061] In addition, in the above embodiment 1, the case where each of the protrusions 31 is in the shape of an inverted truncated cone is illustrated, but the shape of the protrusions may be any shape as long as the tip surface is flat. Other shapes of the protrusions include an inverted elliptical truncated cone, an inverted polygonal truncated pyramid, a cylindrical shape, a polygonal column shape, and the like.

[0062] In addition, in the above-mentioned first embodiment, the system kitchen 100 is exemplified as the water-related equipment. However, the water-related equipment may be any equipment that can get wet with liquid. Other water-related equipment may include equipment installed in a kitchen, a washroom, a toilet, and a bathtub, for example. Equipment installed in a kitchen may include a kitchen counter, a range hood, and the like. Equipment installed in a washroom may include a washbasin, a faucet, and the like. Equipment installed in a toilet may include a toilet seat, a toilet bowl, and the like. Equipment installed in a bathtub may include a bathroom wall, a bathroom floor, a bathroom ceiling, a bathtub, a bathroom door, and the like. In addition, the water-related member may be equipment that can get wet with liquid when installed outdoors.

[0063] In addition, in each of the above embodiments, the resin molded body 1 is exemplified as the molded body, but the molded body may be made of any material that can be laser-machined. Other examples of the material include metals and ceramics.

[0064] In addition, the present invention also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions of each embodiment without departing from the spirit of the present invention. [Explanation of symbols]

[0065] 1 Resin molded body (molded body) 30, 30A uneven structure surface 30a First area 30b Second area 31, 31a, 31b, 31c convex parts 32, 32a, 32b recess 39 Coating materials 100 System kitchen (water equipment) 311 holes τ pitch (predetermined pitch)

Claims

1. a concave-convex structure surface in which a plurality of concave portions and a plurality of convex portions are alternately and repeatedly arranged along a predetermined direction and are arranged in a plane to exhibit liquid repellency; In the uneven structure surface, at least one hole is formed in a tip surface of half or more of the protrusions so as to extend in an axial direction of the protrusions, and no hole is formed in a tip surface of the remaining protrusions, A coating material different from the material constituting the protrusion is applied around the hole, The holes are filled with the coating material. Molded body.

2. The convex portion has a shape in which the tip portion is enlarged more than the base portion. The molded article according to claim 1.

3. The outer peripheral surface of the protrusion has a shape in which the distance from the central axis of the protrusion to the edge gradually increases from the base to the tip. The molded article according to claim 2.

4. The outer circumferential surface of the protrusion has a convex curved shape. The molded article according to claim 3.

5. The outer circumferential surface of the protrusion has a spherical shape. The molded article according to claim 4.

6. The concave-convex structure surface has a pure water static contact angle of more than 120°. The molded article according to any one of claims 1 to 5.

7. The uneven surface has a static contact angle of oleic acid of 90° or more. The molded article according to any one of claims 1 to 6.

8. the plurality of recesses and the plurality of protrusions are alternately and repeatedly arranged at a predetermined pitch along the predetermined direction, A plurality of regions having different predetermined pitches are provided in the concave-convex structure surface. The molded article according to claim 6 or 7.

9. In the concave-convex structure surface, the regions in which the predetermined pitches are different from one another have static contact angles with pure water that differ by 5° or more. The molded article according to claim 8.

10. A method for producing the molded body according to any one of claims 1 to 9, comprising the steps of: The uneven structure surface is formed by performing laser processing on the surface of the base material. A method for producing a molded body.

11. After forming the concave-convex structure surface, the tip surfaces of the convex portions are subjected to laser processing to form the holes. A method for producing the molded article according to claim 10.

12. The laser processing is ablation processing using a pulsed laser. A method for producing the molded article according to claim 10 or 11.

13. The molded article according to any one of claims 1 to 9 is provided. Water-related equipment.

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