JP2015223203A - Surface structure of article having water repellency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface structure of an article having water repellency.SOLUTION: A surface structure of an article having water repellency comprises a plurality of salients 10 arranged along the surface of the article and individually having longitudinal directions. The surface structure is characterized: in that salients 10 have surfaces inclined at least partially from the horizon; and in that the apexes of the salients 10 have a plurality of microspikes 12 formed transversely of the longitudinal direction so that the apexes of said salients 10 may have a plurality of microspikes 12 formed across the longitudinal direction so as to guide water droplets on the surface of said apex may not be extended in the longitudinal direction.

Description

  The present invention relates to a surface structure of an article, and more particularly to a surface structure of an article that can quickly remove droplets on the surface.

  Industrial vehicles such as forklifts and bulldozers, or seats such as golf carts are not completely covered, unlike general passenger cars. When getting on and off repeatedly while it is raining, seat users must wipe off the water adhering to the seat with a towel, etc., or wet the clothes with the seat wet in the rain. Sometimes it is inconvenient. In case of heavy rain or heavy rain, there will be no opportunity to get on and off the wet seating area due to construction or competition, or the wetness of the seating area will not be a problem as a result of taking measures such as wearing rain feathers. However, it is not rain that would cause construction or competition to be canceled, and if measures such as rain and feathers cannot be taken due to light rain or sudden rain, the water in the seating area will be used for users of industrial vehicles, golf carts, etc. Wetting becomes a problem.

  Conventionally, it is composed of a cushion material, a skin material that covers the surface of the cushion material, and a bottom plate that supports the bottom surface of the cushion material as a vehicle seat that is used outdoors or the seat is exposed outdoors. A vehicle seat using a waterproof skin material such as a synthetic resin sheet has been proposed (Japanese Patent Laid-Open No. 2004-261411: Patent Document 1).

  In addition, a golf cart mat having a lattice-shaped uneven portion, a hole, and a drain groove has been proposed to prevent the pants from getting wet when the golf cart is used on a rainy day. (Japanese Unexamined Patent Application Publication No. 2004-194750: Patent Document 2).

  Surface structures of articles other than seats used in situations where water droplets or the like are likely to adhere have also been proposed. For example, in a bathroom floor panel, a non-slip convex portion is formed on the surface so as to be surely dried the next day, and a flow path continuous to a drain outlet or a sink groove is formed between these convex portions, Furthermore, there has been proposed a bathroom floor panel in which at least a concavo-convex shape portion that destroys the surface tension of a polka dot is superimposed on a flow path (Japanese Patent Laid-Open No. 2002-54295: Patent Document 3).

  A construction or building component having a non-slip effect and a drying property, wherein the surface has fine irregularities showing hydrophilicity with a water contact angle of less than 60 degrees, and the fine irregularities are relatively large. A combination of undulation and relatively small irregularities has been proposed (Japanese Patent Laid-Open No. 2005-336997: Patent Document 4).

JP 2004-261411 A JP 2004-194750 A JP 2002-54295 A JP 2005-336997 A

  The seats that have been proposed in the past are simply waterproofed so that rainwater or the like will not soak into the cushion material and wet the occupant's clothing, so that the water adhering to the surface of the seat can be removed. Since it did not have a structure, it was necessary to wipe off water remaining on the surface when repeatedly getting on and off. In addition, the mats having drain grooves that have been proposed in the past are likely to leave rain on the convex portions and do not have sufficient water removal performance.

  In addition, the bathroom panel proposed in the past is designed to reduce the amount of polka dots that can remain independently on the upper surface of the convex shape without flowing into the flow path partitioned around the convex shape in an average bathroom environment. (For example, in an environment of a temperature of 15.3 ° C. and a humidity of 66%), it is suppressed to 2CC or less, which can be naturally dried in about 8 hours, until polka dots remain on the upper surface of the convex portion for a while and dry. It took a long time.

  Conventionally proposed construction or building components are also used for articles where it is desirable to remove water in a short time because the surface is made with hydrophilic specifications and the water is spread thinly and dried by evaporation. The water removal performance was not sufficient.

  In view of the above problems, the present invention eliminates the need for the user of the article to wipe off the water on the article surface such as the seating part when the article such as a seat is used in a state where water droplets are easily applied. It is an object of the present invention to provide a surface structure of an article having improved water removal performance that does not get wet. In particular, it is an object of the present invention to provide a surface structure of an article whose surface is quickly dewatered when water is applied.

  Moreover, this invention aims at providing the surface structure which can be used for the various articles | goods which preferably have the improved water removal performance, without being limited to a seat.

  An object of the present invention is to provide a surface structure of an article that has anti-slip performance and / or ventilation performance in addition to water removal performance and contributes to improvement of user convenience. Furthermore, it aims at providing the surface structure of the article | item which has durability and can maintain the outstanding water removal performance even if it uses it indoors and outdoors for a long time.

  The surface structure of an article having water removal performance according to one aspect of the present invention that solves the above problem includes a plurality of protrusions each having a longitudinal direction, which are arranged along the surface of the article, A plurality of microprotrusions having a surface inclined at least partially from the horizontal, wherein the top of the convex portion is formed across the longitudinal direction to guide water droplets on the surface of the top so as not to spread in the longitudinal direction. It is characterized by having.

  Thus, since the convex part of the surface structure which concerns on this invention has the surface inclined from the horizontal, the water droplet on a convex part can fall below. Furthermore, since the top of the convex portion has a plurality of minute projections that guide the water droplets on the surface of the top portion so as not to spread in the longitudinal direction, the water droplets on the convex portion can fall more efficiently, and the surface of the article Water droplets can be removed in a short time. According to the surface structure of the present invention, the surface of the article is not substantially wetted even when water droplets are continuously or intermittently applied to the surface of the article, such as in rainy weather.

  Suitably, a plurality of convex parts are arranged so that what covers an article does not touch the bottom of a plurality of concave parts formed between adjacent convex parts. By doing in this way, even if it is a case where the water droplet removed from the convex part flows into a recessed part and the water droplet stays in a recessed part, what covers an article | item does not get wet.

  Illustratively, the article may be a seat, and what covers the surface of the article may be a seated person (part of the body) sitting on a seating portion of the seat. Further, for example, the article may be a dewatering / anti-slip component disposed to prevent indoor and outdoor stairs, escalators, passages, floors, and the like from slipping due to wetness, etc. The thing covering the article may be a passerby (a part of the body) passing through a staircase, a floor or the like having the component.

  Preferably, at least part of the bottom of the recess is tilted from the horizontal. By doing in this way, a recessed part becomes an effective drainage channel of the water droplet which flows in from a convex part, and the water droplet of the whole surface structure which consists of a convex part and a recessed part can be removed reliably.

  Preferably, the cross-sectional shape of the top of the convex portion is a semicircle. Thus, when the top part of a convex part has the surface shape corresponding to the curved surface of a semi-cylinder, the water droplet of a convex part tends to flow, and it is easy to fall below. It is preferable that the width of the convex portion (diameter of a semicircular circle) is greater than 0 mm and does not exceed 4 mm. The width of the convex portion may be in the range of 0.5 mm to 4.0 mm.

  Furthermore, the surface structure according to the present invention preferably has a hydrophilic surface. By doing so, water droplets on the surface structure can be more efficiently removed.

  The longitudinal direction of each of the plurality of convex portions may be parallel. The plurality of convex portions may have a single longitudinal direction. Moreover, the some recessed part formed between adjacent convex parts may have a parallel longitudinal direction or a single longitudinal direction, respectively. By doing in this way, a water droplet can be efficiently drained in a predetermined direction.

  It is preferable that the pitch between the convex portions does not exceed 8 mm. The pitch between the convex portions may be in the range of 1 mm to 8 mm. As described above, by appropriately narrowing the interval between the convex portions, it is possible to prevent a material covering the article from entering the concave portion and getting wet.

  Preferably, the plurality of microprojections are formed so as to guide water droplets having a diameter of 8.0 mm or less. In general, the size of water droplets and ice crystals in the cloud is 0.2 mm or less in diameter, and if it exceeds this, it will rain and fall to the ground. In the developed rain cloud, there is a strong updraft, so the water droplets that fall on the ground by overcoming the updraft are the one that has become larger as a result of the water droplets becoming one in the cloud, and the expected maximum diameter Is 6-8 mm. By configuring so as to guide water droplets of the above size, it is possible to obtain a practical surface structure of an article suitable for a seat or the like used outdoors in rainy weather.

  It is preferable that the pitch between the microprotrusions does not exceed 4.5 mm. The pitch between the microprotrusions may be in the range of 0.4 mm to 4.5 mm. Moreover, it is preferable that the length along the longitudinal direction of a microprotrusion is larger than 0 mm and does not exceed 2 mm. The length along the longitudinal direction of the microprojections may be in the range of 0.2 mm to 2.0 mm. Thus, the movement direction of a water droplet can be guided by setting it as a micro projection sufficiently small with respect to the diameter of the assumed water droplet.

  The surface structure of the article according to the present invention may be composed of a skin material covering the article. The skin material may be made of a water-repellent material processed so that the surface exhibits hydrophilicity. By doing in this way, a water drop does not penetrate | invade into the main body of an article | item, and the water drop on the surface of an article | item can be removed. Further, the surface structure can be easily applied to various forms of articles.

  By carrying out the surface structure of the article with improved removal performance according to the present invention, there is no need to remove water drops on the surface with a towel, etc., even in situations where water drops are easily applied, and users of the articles do not get wet. . For example, when the article is a seat, by applying the surface structure of the present invention, a comfortable seat that can be used without worrying about getting wet even in rainy weather can be obtained.

  According to the present invention, water droplets do not exist on the surface of an article that is touched by what covers the article. Therefore, by implementing the present invention, it is possible to obtain an article having high anti-slip performance in addition to high water removal performance. By applying the surface structure according to the present invention to articles used indoors and outdoors, a highly safe construction or building component that does not slip due to water wetting can be obtained.

  Moreover, since this invention implement | achieves water removal performance irrespective of the fine surface shape of nanometer level, it has high weather resistance. ADVANTAGE OF THE INVENTION According to this invention, the practical water removal structure which can be applied to the various articles | goods used indoors and outdoors can be obtained.

FIG. 1 is a diagram schematically showing droplets on a solid surface. FIG. 2 is a diagram schematically illustrating an exemplary contact angle. FIG. 3 is a diagram schematically showing the falling angle, the advancing contact angle, and the receding contact angle. FIG. 4 is a conceptual diagram related to the equation of Furmidage. FIG. 5 (A) is a diagram schematically showing an example of an article to which the surface structure according to the present invention is applied. FIG. 5B is a cross-sectional view taken along the line XX in FIG. FIG. 6A is a perspective view schematically showing the surface structure of one embodiment according to the present invention, in which the portion s of FIG. 5B is enlarged. FIG. 6B is a side view schematically showing an enlarged convex portion of the surface structure of one embodiment according to the present invention. FIG. 7 is a front view schematically showing an end face of the surface structure according to one embodiment of the present invention.

  Various features of the present invention will now be described with reference to the drawings, together with preferred embodiments not intended to limit the invention. The drawings are simplified for illustrative purposes, and the scales do not necessarily coincide.

  In order to form the surface structure of an article having improved water removal performance, static wettability and dynamic wettability were studied as follows to control the wettability of the article (solid) surface.

Referring to FIG. 1, when a liquid is dropped on the surface of the solid, the liquid surface tension γ _L , the solid surface tension γ _S , and the solid / liquid interfacial tension γ _SL are balanced, and a certain shape is obtained. . This relationship is well known as Young's equation: γ _S = γ _SL + γ _L cos θ. When a water droplet maintains a certain shape on a horizontal solid surface, the surface of the water droplet becomes a curved surface and forms a certain angle at the point of contact with the solid surface. This angle θ is called a contact angle. If the intersection point between the contour curve of the droplet and the solid surface is an end point P, the contact angle θ (0 ° ≦ θ ≦ 180 °) is the angle formed by the tangent to the contour curve of the droplet and the solid surface at the end point P. is there. The state in which the liquid is in contact with the surface of the solid is referred to as wetting, and the degree of wetting is referred to as wettability, which is evaluated by the contact angle θ.

  Referring to FIG. 2, those having a low contact angle (for example, contact angle θ1) have good wettability, and those having a high contact angle (for example, contact angle θ3) have poor wettability. A state where the contact angle θ is low and wettability is good (wet and spread easily) is called hydrophilicity. A state where the contact angle θ is high and the wettability is poor (water is repelled and the contact area between the liquid and the solid is small and difficult to wet) is called water repellency or hydrophobicity.

The contact angle θ is determined by the combination of the surface tension γ _{L of} the liquid and the surface tension γ _S of the solid. For example, the surface tension γ _L of water is 72.75 dyn / cm, the surface tension γ _S of PVC is 39 dyn / cm, and the contact angle θ of water with respect to PVC is 68 °. In general, the contact angle θ becomes higher as the surface tension γ _{L of} the liquid is larger than the surface tension γ _{S of the} solid.

  In this specification, the term “hydrophilic” is used to describe a surface having a contact angle with water of less than 60 °. The term "water repellency" or "hydrophobicity" is used to describe a surface with a contact angle with water exceeding 60 °. A surface made of a PVC material having a water contact angle θ of 68 ° exhibits slightly water repellency. The water contact angle with respect to inorganic materials such as glass is 20 ° to 30 ° and hydrophilic, and the water contact angle with respect to resin materials such as PE is 70 ° to 90 °. The water contact angle with the fluorine-based material is about 90 ° and exhibits water repellency.

  With reference to FIG. 3, a drop is placed on a horizontal solid surface, the solid surface is gradually inclined, and the inclination angle α when the water droplet starts to slide is called a falling angle (sliding angle). The contact angle of the forward end point when the water droplet starts to move when the water droplet expands is referred to as the forward contact angle θa, and the contact angle when the water droplet starts to move when the water droplet contracts on the opposite side is referred to as the receding contact angle θr.

Referring to FIG. 4, when the landing liquid whose shape is assumed to be approximately rectangular falls in the direction of the arrow, the potential energy W = wγ _L dl (cos θr−cos θa) lost due to the drop of the droplet is caused by wetting and spreading. Assuming that work W = mg sin α dl,

It becomes. The above is well known as the Furmidge equation. m is the mass of the droplet, g is the acceleration of gravity, α is the drop angle of the droplet, w is the drop direction of the droplet in the direction perpendicular to the direction in which the droplet with a parallel shape of the opposite side falls. The width, dl is the amount of movement of the droplet, γ _L is the surface tension of the liquid, θa is the advancing contact angle, and θr is the receding contact angle.

Solving the above formula for the fall angle with respect to the sliding angle α, the following is obtained.

  The difference between the advancing contact angle θa and the receding contact angle θr (cos θr−cos θa) is referred to as contact angle hysteresis. From the above formula, the smaller the contact angle hysteresis, the smaller the sliding angle α. That is, the water droplet falls with a lower inclination angle as the contact angle hysteresis is smaller.

  In order to reduce the contact angle hysteresis, it is conceivable to decrease the advancing contact angle θa (increase cos θa) and / or increase the receding contact angle θr (decrease cos θr). It is difficult to independently control the receding contact angle θr.

  Using a solid surface with super water repellency (contact angle θ ≧ 150 °), the contact angle hysteresis can be made extremely small, and the falling angle α can be made extremely small (for example, about 1 °). However, in order to obtain a super water-repellent surface, nano-level surface processing that forms a fine surface shape capable of biting air is required. Such a super water-repellent surface has extremely poor durability and low practicality.

  The inventor paid attention to the fact that the falling angle α decreases as the mass m of the water droplet (droplet) increases from the above formula of Furmidge. That is, if the mass m of the water droplet can be increased, it was considered that even if the inclination angle of the solid surface is relatively small, the water droplet is likely to fall down and the solid surface is easily dewatered.

  Regarding increasing the mass m of the water droplet, the inventor considered that a water droplet having a large mass can be formed if a plurality of (for example, two) water droplets can be collected on the surface of a solid article. Therefore, the surface shape guided so that individual water droplets can be easily gathered was considered suitable.

  Further, from the above formula of Furmidge, even if the mass m of the droplet increases, if the width w perpendicular to the direction in which the water droplet moves correspondingly increases, the falling angle is difficult to decrease. It was considered that a surface shape that suppresses an increase in the width w perpendicular to the moving direction of the water droplet while increasing the mass m of the water droplet is suitable.

  Furthermore, the inventor considered that a surface shape in which not only water droplets start to move but also water droplets move with sufficient falling speed and falling acceleration is suitable for a surface having improved water removal performance. When the water droplets started to move with a relatively small inclination, it was thought that if the inclination increased according to the moving direction, the water drops could move and fall at an accelerated rate.

  In addition to the surface shape as described above, the inventor has a plurality of water droplets gathered together on the surface of the article, so that each water droplet spreads wet and can be gathered with water droplets on a nearby surface. A surface structure exhibiting hydrophilicity was considered suitable.

  The surface structure according to the present invention as described above can be applied to an article 1 that is a seat for a golf cart as shown in FIG. As well shown in the XX cross-sectional view of FIG. 5B, the surface structure 100 according to the present invention may be made of a skin material that at least partially covers the main body 200 of the article 1. For example, the article 1 that is a seat includes a main body 200 made of a cushion member such as urethane, a support member 300 such as a bottom plate that supports the bottom surface of the main body 200, and a surface that covers the main body 200 and has an end portion fixed to the support member 300. It consists of structure 100.

  The upper surface (sitting portion) of the article 1 composed of the surface of the surface structure 100 forms a gently curved surface according to the shape of the main body 200. The inclination of the upper surface of the article 1 in the front-rear direction of the seat from the horizontal is indicated by an arrow A. Of the upper surface of the article 1, the portion s is horizontal, and the front side and the rear side of the portion s are inclined from the horizontal.

  The shape of the upper surface of the article 1 is exemplary, and the shape of the upper surface may not have a horizontal portion and may not have a portion inclined from the horizontal.

  FIG. 6A schematically shows a surface structure 100 according to an embodiment of the present invention, in which a part of the horizontal portion s in FIG. 5 is enlarged.

  As illustrated, the surface structure 100 includes a plurality of convex portions 10 arranged along the surface S <b> 1 of the main body 200. Each of the plurality of convex portions 10 extends along an arrow A that is the front-rear direction of the article 1. That is, in one embodiment, each of the plurality of convex portions 10 has a longitudinal direction A that is parallel to each other in the front-rear direction of the article 1. The longitudinal direction A is horizontal at the portion s, and is inclined from the horizontal at the front side and the rear side of the portion s.

  The longitudinal direction of the convex portion 10 need not be limited to the front-rear direction of the article. In another embodiment, the convex portion 10 may have a longitudinal direction that is the left-right direction of the article 1. The longitudinal directions of the plurality of convex portions 10 may not be parallel to each other. Or the some convex part 10 may have a longitudinal direction which is a radial direction concerning one center of the articles | goods 1, respectively.

  The convex portion 10 includes a top portion 11 that is an upper portion (indicated by a one-dot chain line), and may further include a lower portion 13 that is a lower portion.

  In one embodiment, the cross-sectional shape of the top portion 11 is a semicircle of a circle having a predetermined radius r1. Since the top part 11 which is the upper part of the convex part 10 has a semi-cylindrical shape in this way, a soft feeling can be given to what is placed thereon. For example, when the article 1 is a seat, the seated person can be provided with a comfortable sitting comfort.

  A vertex E1 of the top 11 is defined by the vertex of the semicircle of the top 11 (indicated by a broken line). The ridge line E1 is equal to the longitudinal direction A and is horizontal in the portion s. (In other parts, it inclines from the horizontal according to the longitudinal direction A.) The part excluding the ridge line E1 on the surface of the convex part 10 in the part s inclines from the horizontal. The inclination of the surface of the top portion 11 increases as the distance from the ridge line E1 to the side (direction crossing the longitudinal direction A) increases according to the curved surface of the semi-cylinder. Thus, since the convex part 10 has the surface inclined from the horizontal, the water droplet of the convex part 10 can fall below according to gravity.

  The cross-sectional shape of the top 11 is not limited to a semicircular shape, and may be a part such as an ellipse. In another aspect, the cross-sectional shape of the top portion 11 may be a polygonal shape such as a triangle. The surface inclined from the horizontal of the top 11 may be composed of a single curved surface and / or a single plane, and may be composed of a plurality of curved surfaces and / or a plurality of planes.

  A concave portion 20 is formed between adjacent convex portions 10. In one embodiment, the bottom surface S2 of the recess 20 is parallel to the surface S1 of the main body 200 and is horizontal in the portion s. The bottom surface S2 has a longitudinal direction A according to the convex portions 10 on both sides.

  In other embodiments, the bottom surface S2 may be inclined from the horizontal. Further, the longitudinal direction of the bottom surface S2 may be different from the longitudinal direction of the convex portions 10 on both sides.

  The top portion 11 has a plurality of minute protrusions 12 on the surface. The plurality of minute protrusions 12 are formed across the longitudinal direction A (ridge line E1). Each microprotrusion 12 may be formed perpendicular to the longitudinal direction A (ridge line E1).

FIG. 6B shows an enlarged view of a part of one convex portion 10 viewed from the side in the longitudinal direction A. Preferably, each microprotrusion 12 has a curved ridge line E2 continuous with the ridge line E1 (connecting the ridge line E1 at both ends) and a curved ridge line E3 orthogonal to the ridge line E2. The microprotrusion 12 has a vertex T at the intersection of the ridgeline E2 and the ridgeline E3. Vertex T has a height _{h 2} with respect to edge line E1.

Such a shape in the vicinity of the apex T of the microprotrusion 12 preferably includes a shape obtained by partially cutting the top of the sphere. Radius of the circle of cross-section taken spheres are shown as r _2. For this reason, the surface of the microprotrusion 12 has an inclination in any direction from the apex T. The microprotrusions 12 are for removing water droplets from the convex portion 10 more efficiently and quickly.

  Specifically, the behavior of each of the water droplet D1 in the vicinity of the ridge line E1 of the top 11 and the water droplet D2 in the vicinity of the apex T of the microprojection 12 (each indicated by a substantially semicircular broken line) was examined. The water droplets D1, D2 were assumed to have a circular contact surface with a diameter d on the surface structure 100 according to the amount of water droplets and the wettability of the surface of the surface structure 100. Assuming a state in which minute raindrops fall, it is assumed that the circular contact surfaces of the water droplets D1 and D2 each have a diameter d = about 0.5 mm.

  Since the microprojection 12 has an inclination in any direction from the apex T as described above, the water droplet D2 can move radially from the microprojection 12 in any direction. When the water droplet D2 moves in the direction along the ridgeline E3, it can fall to the side of the convex portion 10 due to a steep inclination.

  When the water droplet D2 moves in the longitudinal direction A, for example, the water droplet D2 can be combined with other water droplets of the top portion 11 such as the water droplet D1. By combining two (or more) water droplets, a water droplet having an increased mass is formed on the top 11. The collected water droplets try to spread at the top portion 11, but spread in the longitudinal direction A is limited by the front and rear microprojections. The water droplets that can no longer spread in the longitudinal direction A will spread in a direction crossing the longitudinal direction A. By guiding the direction in which the water droplet spreads in the direction crossing the longitudinal direction A, it can be efficiently dropped by the steep inclination of the surface of the convex portion 10 in the direction crossing the longitudinal direction A. Thus, the microprotrusions 12 can move the water droplets on the microprotrusions and can be dropped by themselves, or can be gathered together with other water droplets, and the width in the direction across the moving direction of the collected water droplets Can be dropped from the top 11 in a shorter time (for example, instantaneously) than a single water droplet.

It is preferable that the length of the ridgeline E2 of the microprotrusion 12 is determined so that two or more water droplets having a diameter d are not spaced apart. By using such a minute protrusion, a water droplet easily moves from the minute protrusion. It is preferable that the length l ₂ (r ₂ × 2) of the straight line connecting both ends of the ridge line E2 with a straight line is greater than 0 mm and does not exceed 2 mm. The straight line length l ₂ may be in the range of 0.2 mm to 2.0 mm. The length l ₂ is preferably greater than 0 mm and does not exceed 1 mm.

The height _{h 2} of the vertex T of the minute projection 12 against ridge E1 is greater than 0 mm, preferably does not exceed 0.2 mm. The height _{h 2} of the vertex T of the minute projection 12 may be in the range of 0.02Mm～0.2Mm.

The water droplet D1 in the vicinity of the ridge line E1 of the top portion 11 is likely to move and drop to the side (in the direction crossing the longitudinal direction A) where the inclination is gradually larger than the horizontal longitudinal direction. Further, as described above, two or more water droplets are collected on the top portion 11 by moving the water droplets from the minute protrusions 12 or by dropping other water droplets on the top portion 11 from the air. Cheap. As described above, since the ridge line E1 is divided into the length l ₁ by the minute protrusions 12, the collected water droplets cannot spread beyond the length l ₁ along the longitudinal direction A and move sideways. Guided and can be removed more quickly.

When the water droplet D1 having a diameter d = 0.5 mm in the longitudinal direction is located in the vicinity of the center of the length l ₁ , other water droplets having the same diameter d are positioned at intervals before and after the longitudinal direction A. You may decide not to do it. Alternatively, it may be determined that other water droplets having the same diameter d are positioned at a very slight distance in front and rear along the longitudinal direction A so as to use a force that attracts adjacent water droplets to each other. By doing in this way, it becomes easy to unite with the water droplet which moved from the microprotrusion 12, and the water droplet on the top part 11 can be removed faster. Fine water droplets can be efficiently collected and dropped in a short time, and larger water droplets can be dropped in a short time even with a single water droplet, and a surface shape with improved water removal performance can be obtained.

The length l ₁ is preferably greater than 0.0 mm and does not exceed 2.5 mm. The length l ₁ may be in the range of 0.2 mm to 2.5 mm.

  As described above, the water droplets on the convex portion 10 can fall according to the inclination of the convex portion 10, and moreover, the water droplets on the convex portion 10 are guided by the minute protrusions 12, and two or more water droplets are easily collected, and It is suppressed that the collected water droplet spreads in the longitudinal direction A on the top portion 11 and can fall from the convex portion 10 in a short time, and the surface structure 100 has improved water removal performance.

  In addition to the characteristic surface shape described above, the surface structure 100 preferably exhibits hydrophilicity. By doing in this way, a water droplet spreads on the convex part 10, the space | interval of adjacent water droplet becomes small, and it becomes easier to unite. Since the water droplets are more easily collected, the water droplets can be removed from the convex portion 10 in a shorter time.

  The surface contact angle of the surface structure 100 exhibiting hydrophilicity is less than 60 °, 50 ° or less, 40 ° or less, 30 ° or less, 20 ° or less, 10 ° or less, 5 ° or less, 4 ° or less, 3 ° or less, It may be 2 ° or less, or 1 ° or less. Preferably, the contact angle is 10 ° or less, or 5 ° or less.

  The surface structure 100 exhibiting hydrophilicity may be formed by applying a hydrophilic coating to a skin material having a plurality of convex portions 10 formed on the surface.

  Preferably, the base material of the skin material may be made of a water repellent material selected so that water droplets do not penetrate into the main body 200. The water-repellent material may be a polyvinyl chloride leather (hereinafter, PVC leather) in which a soft polyvinyl chloride layer is laminated on the surface of a fiber substrate such as a woven fabric, a knitted fabric, or a nonwoven fabric. Alternatively, the material of the skin material may be soft polyvinyl chloride alone (PVC film), hard polyvinyl chloride, polypropylene, ABS resin, or the like.

The coating agent for hydrophilic coating of the base material of the skin material is illustratively from a hydrophilic resin such as acrylic acid or polyvinyl alcohol, a colloidal inorganic oxide such as SiO ₂ or Al ₂ O ₃ , or a photocatalyst such as TiO _2. And a base solvent and an organic solvent such as an aqueous solvent or alcohol. When PVC leather is used for the skin material, an alcohol solvent is desirable in consideration of wettability.

  Such a coating agent may be applied by spraying, brushing, spin coating, dipping, roll coater or the like to the surface of the substrate on which irregularities are formed. If the substrate is made of a water-repellent material and the surface tension is low and coating is difficult, pretreatment such as corona discharge treatment or plasma discharge treatment will modify the substrate surface and improve wettability for coating. Can improve sex.

  Alternatively, the surface structure 100 may be formed by laminating a hydrophilic film on the base material of the skin material. Such a hydrophilic film is made of a material having hydrophilicity such as a kneaded antifogging agent or antistatic agent inside the film, a surface coating of a hydrophilic agent, or an acetate material. Good.

  The article having the surface structure 100 covers, for example, the surface of the article main body 200 made of foamed resin or the like formed into a predetermined shape with the sheet-like surface structure 100 in which desired irregularities are formed by pressing, and the end portion is sewn. It can be produced by wearing. In addition, an article having the surface structure 100 can be manufactured by a method that can be appropriately selected by those skilled in the art.

  The surface structure 100 may be made of a hydrophilic material. The surface structure 100 may be integral with the main body 200.

  The surface structure 100 exhibiting hydrophilicity has a so-called self-cleaning performance in which dust, dirt, and the like can be easily washed away with water.

  FIG. 7 schematically shows a partial end face of the surface structure 100 according to one embodiment of the present invention and an outline C (broken line) of the surface structure 100 (for example, a part of the body of a seated person). (The minute protrusion 12 is omitted). The direction perpendicular to the paper surface is the longitudinal direction A. Water droplets removed from the top 11 flow into the recess 20 (colored portion). When the bottom surface S <b> 2 of the recess 20 (the surface S <b> 1 when the surface structure 100 is integrated with the main body 200) is horizontal, water droplets can collect in the recess 20.

  The outline C of what covers the article may be planar depending on what covers the article. Alternatively, the outer shell C may be a curved surface or an uneven surface depending on what covers the article. Preferably, the material, shape, size, arrangement, and the like of the convex portion 10 are determined so that the outer shell C does not enter the concave portion 20 deeply and does not touch the bottom surface S <b> 2 of the concave portion 20. By doing in this way, the surface of the article which the outline C of the article covering touches mainly becomes the top 11 of the convex part 10, and even if water accumulates near the bottom surface S2, the article covering does not touch the water.

As the surface of the article touching the outer C of those covering the article made from the top 11, the width w ₁ of the convex portion _10, greater than 0mm any width w ₂ of the recess 20 preferably does not exceed 4 mm. The width w ₁ and the width w _{2 of the} recess 20 may each be in the range of 0.5 mm to 4.0 mm.

The convex part 10 may consist of only the top part 11 and may consist of the top part 11 and the lower part 13. Preferably, the top portion 11 has a semicircular cross-sectional shape and the lower portion 12 has a rectangular cross-sectional shape. The height h ₁ (or h ₁ + h ₃ ) of the convex portion from the bottom surface S2 to the apex (ridge line E1) of the top portion 11 can represent the depth of the concave portion. The height h ₁ (or h ₁ + h ₃ ) of the convex portion may be determined so that the material covering the article does not touch the water accumulated in the concave portion.

For example, the height h ₁ (or h ₁ + h ₃ ) of the convex portion may be determined based on the assumed rainfall and the usage mode of the article. For example, when the rainfall for 1 hour is 1 mm and the ratio of the convex portion and the concave portion occupying the unit area of the article is equal (the pitch of the convex portion 10 and the concave portion 20 is equal), water having a depth of 2 mm in the hour Can accumulate. For example, when an article that is used for 1 hour when the rainfall for 1 hour is 1 mm is assumed, the height h ₁ (or h ₁ + h ₃ ) of the convex portion can be greater than 2 mm.

  Preferably, the bottom surface S2 is at least partially inclined with respect to the horizontal. Referring to FIG. 5B, the upper surface of the article 1 that is a seat has an inclination along the arrow A in the front-rear direction, so that water droplets falling from the convex portion 10 to the concave portion are forward from the portion s, or It can be drained backwards from the part s. By doing in this way, the whole surface structure 100 which consists of the convex part 10 and the recessed part 20 is dehydrated.

When the water in the concave portion 20 is drained, the height of the convex portion 10 may be the height h ₁ of the top portion 11 and is preferably 0 mm <h ₁ ≦ 2 mm. Protrusion 10 may have a height _{h 1} of 0.2 mm ≦ _{h 1} ≦ 2.0 mm. Moreover, the height of the convex part 10 may be the height h ₁ + h ₃ of the top part 11 and the lower part 13, and may be 0 mm ≦ h ₁ + h ₃ ≦ 6 mm. The convex part 10 may have a height h ₁ + h ₃ of 0.6 mm ≦ h ₁ + h ₃ ≦ 6.0 mm.

Seat for golf carts Example embodiment, the cushion material of the seat, which is produced by coating the surface structure of the skin material consisting of PVC leather with a hydrophilic treatment on the surface. The longitudinal directions of the bottom surfaces of the plurality of convex portions and the plurality of concave portions of the surface structure are the front-rear direction of the seat and are parallel to each other, and most of them are tilted from the horizontal as shown in FIG. The semicircular radius (r ₁ ) of the cross section defining the surface of the top of the convex portion is about 1.0 mm, the height of the convex portion (h ₁ + h ₃ ) is about 2.5 mm, and the width of the convex portion (w ₁ ), The width (w ₂ ) of the recesses was about 2.0 mm. The length (l ₂ ) in the longitudinal direction of the microprojections formed on the top surface of the convex portion is about 0.9 mm, the height (h ₂ ) of the apex T of the microprojections is about 0.1 mm, and the adjacent microprojections The length (l ₁ ) of the ridge line E1 between the microprotrusions was about 1.1 mm (see FIGS. 6 and 7). The contact angle of water with the surface of the surface structure was about 5 °.

Comparative Example 1
The seat for the golf cart of Comparative Example 1 was the same as the example except that the surface structure did not have microprojections.

Comparative Example 2
The golf cart seat of Comparative Example 2 was the same as the Example except that the hydrophilic structure was not applied and the surface structure exhibited water repellency. The contact angle of water with the surface of the surface structure of the comparative example was 68 °.

  The experiment was conducted by placing the seats of the example, comparative example 1, and comparative example 2 outside in the rain. The seat of the example was immediately drained without water droplets remaining on the convex part and the concave part, and the clothes and the like did not get wet when the experimenter sat down. The seat of Comparative Example 1 remained in a state where water droplets spread over the convex portions and could not be seated as it was. The seat of Comparative Example 2 had rounded water droplets on the convex portions, and the clothes and the like were slightly wet when seated as they were.

  As described above, the surface structure according to the present invention can remove water droplets very effectively due to the shape and wettability of the surface in which the mass of the water droplet is increased so that the water droplet falls. ADVANTAGE OF THE INVENTION According to this invention, even if it uses it outdoors on rainy weather, a seat which a seated person etc. cannot get wet can be provided. Furthermore, a comfortable seat having appropriate air permeability can be provided due to the unevenness of the surface.

  In addition, according to the present invention, due to the high water removal performance, water drops do not exist on the surface that is touched by what covers the article even in rainy weather, and an article having a high anti-slip effect can be provided. Illustratively, by applying the surface structure of the present invention formed in a sheet shape to a part of the staircase or the like, a safe staircase or the like that can prevent a fall accident in rainy weather can be provided.

  Those skilled in the art will appreciate that many different modifications are possible without departing from the spirit and aspects of the invention. Accordingly, it goes without saying that the embodiments of the present invention are merely examples, and do not limit the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Convex part 11 Convex part top part 12 Microprotrusion 13 Convex part lower part 20 Concave part 20 Concave part 100 Surface structure 200 Article main body S1 Article main body surface S2 Concave bottom E1 Convex edge

Claims (11)

A surface structure of an article having water removal performance,
A plurality of convex portions each having a longitudinal direction, disposed along the surface of the article,
The convex portion has a surface inclined at least partially from horizontal,
The top structure of the convex part has a plurality of minute projections formed across the longitudinal direction so as to guide water droplets on the surface of the top part so as not to spread in the longitudinal direction. A concave portion is formed between adjacent convex portions and convex portions of the plurality of convex portions,
2. The surface structure according to claim 1, wherein the plurality of convex portions are arranged so that an object covering an article does not touch a bottom portion of the concave portion.   The surface structure according to claim 2, wherein at least a portion of the bottom of the recess is inclined from the horizontal.   The surface structure according to claim 1, wherein a cross-sectional shape of a top portion of the convex portion is a semicircular shape.   Furthermore, the surface structure exhibits hydrophilicity, The surface structure described in Claim 1 characterized by the above-mentioned.   The surface structure according to claim 1, wherein longitudinal directions of the plurality of convex portions are parallel to each other.   The surface structure according to claim 6, wherein a pitch between the convex portions of the plurality of convex portions does not exceed 8.0 mm.   The surface structure according to claim 1, wherein the plurality of minute protrusions are formed so as to guide water droplets having a diameter of 8.0 mm or less.   The surface structure according to claim 1, wherein a pitch between the microprotrusions does not exceed 4.5 mm.   The surface structure according to claim 1, wherein the surface structure is made of a skin material covering the article.   The surface structure according to claim 10, wherein the skin material is made of a water-repellent material processed so that the surface exhibits hydrophilicity.