JP2017002268A - Molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve liquid repellency while maintaining mass productivity and durability of a molded body.SOLUTION: A molded body of the present invention has liquid repellency due to a fine uneven shape formed in a surface. The molded body has a plurality of protrusions arranged regularly in a substrate surface. In a plane including apexes of the protrusions, the rate of the area occupied by the protrusions is 0.3 or less. A concavity width w between each of the protrusions and a neighboring protrusion is 40 μm or less. The sliding angle of droplets located on the substrate surface is 90° or less. Thereby, even fine unevenness with little risk of damage during manufacture or use allows droplets to easily fall off the molded body, thus realizing application to component surfaces and various packaging container inner surfaces which require antifouling properties.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a molded product having liquid repellency due to a fine uneven structure provided on a substrate surface.

  Conventionally, by imparting liquid repellency to the substrate surface of parts, water and oil droplets attached to the surface can be repelled and functions such as anti-fouling, anti-fingerprint, anti-fogging, and anti-icing can be achieved. Are known.

  In recent years, the same surface treatment has been applied to shampoos and rinses, liquid detergents, seasonings such as sauces and mayonnaise, toothpastes, retort food containers, and the inner surface and spouts to improve liquid drainage. Therefore, research has been conducted focusing on the effects of facilitating the use of the filling material and the effect of maintaining the spout hygienically.

  Here, the liquid repellency is an index representing the non-adhesiveness and easy removability of a droplet that has reached the surface of the substrate. The larger the contact angle between the substrate surface and the droplet and the smaller the falling angle, the higher the liquid repellency.

As shown in FIG. 1A, the contact angle is an angle formed between the contact surface of the substrate and the interface of the droplet in a state where the droplet is attached to the substrate surface.
The closer the contact angle is to 0 degree, the more easily the substrate and the liquid droplet become compatible.

  Further, the falling angle is an angle at which the surface of the substrate on which the droplet is placed is gradually inclined from the horizontal position and the droplet starts to slide as shown in FIG.

  The closer the tumbling angle is to 0 degrees, the easier it is for the droplets to be removed from the substrate. When the tumbling angle is greater than 90 degrees, the droplets are less likely to leave the substrate.

  However, in the field of surface treatment technology that provides liquid repellency, the improvement of the liquid repellency effect that depends only on the chemical structure of the surface material has reached its limit, and in recent years, due to the combination of the liquid repellent material and the fine uneven structure, A coating agent or sheet having higher liquid repellency has been proposed (for example, Patent Document 1 or 2).

  Patent Document 1 discloses a water / oil-repellent coating article obtained by coating a coating composition containing alcohol, alkoxysilane, perfluoroalkylsilane, silica fine particles, a catalyst for promoting hydrolysis reaction of alkoxysilane, and water. Is described. The mean square roughness value on the surface of the article is 150 nm or more, the contact angle with water is 150 degrees or more, the contact angle with oil is 150 degrees or more, and the falling angle with respect to water droplets is 10 degrees or less.

  It is said that by adding silica fine particles to a material having high water repellency and oil repellency so as to have a surface roughness greater than a specific value, the fallability with respect to water can be improved.

Patent Document 2 includes a concavo-convex shape layer having a fine concavo-convex shape on one surface side, and a water repellent layer formed with a substantially constant thickness on one surface side of the concavo-convex shape layer. At least the surface portion on the surface side of this is a cross-linked product that maintains a fine uneven shape even after heat stretching, and the water-repellent layer is made of an olefin copolymer resin containing hydrophobic oxide fine particles, and has water repellency. Further, a thermoplastic resin sheet and a molded product are described.

  Thereby, excellent water repellency can be obtained, and when used as a packaging material for food, it is said that food hardly adheres.

  In addition, a method has been proposed in which a fine concavo-convex structure is processed directly on the surface of a base material instead of laminating fine particles to give water repellency (for example, Patent Document 3).

  In Patent Document 3, an infinite number of cone-shaped protrusions having a circular or polygonal bottom surface and a diameter of a circular bottom surface or a circle circumscribing the bottom polygon of 50 μm or less are 50 μm. A fine concavo-convex structure arranged two-dimensionally at the following pitch, and comprising a first water-repellent compound comprising an alkoxysilane compound having a fluoroalkyl group or an ethanol compound having a fluoroalkyl group; A water-repellent structure and a water-repellent structure comprising a carbon-containing compound composed of an alkoxysilane compound having a fluoroalkyl group with fewer carbon atoms than an aqueous compound and / or a second water-repellent compound composed of antimony trioxide are described. ing.

  It is said that higher water repellency can be exhibited by a combination of a fine concavo-convex structure formed on the substrate surface and a coating agent made of a compound having high water repellency.

JP 2010-89373 A International Publication No. 2014/087695 JP 2010-201799 A

  However, in the technologies described in Patent Document 1 and Patent Document 2 described above, since the concavo-convex structure is formed by the lamination of the fine particles contained in the coating agent or the lamination of the fine particles having the coating layer, it is easily worn by a tentacle or the like In addition, the fine particles may peel off. As a result, there is a problem that the performance is remarkably deteriorated, and in some cases, there is a problem that the fine particles adhere to the contents of the container or the package.

  In addition to the type of coating agent, the technique described in the above-mentioned conventional patent document 3 shows the size of the bottom surface of the protrusion, the size of the pitch between the protrusions, and the correlation thereof, but the uneven shape is Although it is fine, it is not based on the theory of droplet adhesion suppression, and the definition of the dimensions of the bottom surface portion and the pitch of the protrusion does not make sense as a structure that exhibits liquid repellency. Therefore, it cannot be said that sufficient liquid repellency is surely exhibited even in combination with a coating agent having a certain level of water repellency. In addition, there is no description of the effect on the falling property of the droplet.

  The present invention solves the above-described conventional problems, and a molded article having high liquid repellency can be obtained simply by using a general antifouling coating agent that is not coated with a coating agent or is excellent in heat resistance and durability. It is to provide.

In order to solve the above-described conventional problems, the molded body of the present invention is a molded body having a plurality of protrusions regularly arranged on the surface of a base material, and the apex of the protrusion adjacent to the protrusion. On the virtual plane passing through, the area ratio occupied by the protrusion is 0.3 or less, the recess width w which is the distance between the protrusion and the adjacent protrusion on the virtual plane is 40 μm or less, The drop angle of the droplet located on the surface of the substrate is 90 ° or less.

  According to this, even if it is an uneven structure of the order of μm which is easy to manufacture and has a relatively high durability, the intrusion of liquid droplets is suppressed and the tumbling property is excellent.

  The molded body of the present invention has an uneven structure on the order of μm that makes it difficult for liquid droplets that have reached the surface to adhere to the surface, and is easy to remove. Therefore, the molded body has excellent moldability and durability. It can be used as an antifouling surface or an inner surface of a container or packaging material.

(A) explanatory diagram of contact angle, (b) explanatory diagram of sliding angle Sectional drawing of the molded object in Embodiment 1 of this invention The cross-sectional enlarged view of the uneven | corrugated surface of the molded object in Embodiment 1 of this invention The cross-sectional enlarged view of the uneven | corrugated surface of the molded object in Embodiment 1 of this invention Plan view of the surface of a molded body in Embodiment 1 of the present invention (A) Explanatory drawing of the path of the droplet interface moving on the concavo-convex structure on the substrate surface, (b) Explanatory drawing of the path of the droplet interface moving through the apex of the protrusion on the substrate surface Sectional drawing of the uneven | corrugated surface of the molded object in the modification of this invention

  The molded body of the first invention is a molded body having a plurality of protrusions regularly arranged on the surface of the base material, on a virtual plane passing through the apex of the protrusion adjacent to the protrusion, The area ratio occupied by the protrusions is 0.3 or less, the recess width w, which is the distance between the protrusions on the virtual plane and the adjacent protrusions, is 40 μm or less, and the liquid droplets are located on the substrate surface The falling angle is 90 ° or less.

  Of the concavo-convex structure on the surface of the substrate, high liquid repellency can be obtained by regulating the area ratio occupied by the protrusions, the width of the recesses, and the falling angle.

  Also, since the drop angle of the liquid droplets is 90 ° or less, for example, when using the molded body of the present invention inside a packaging material or container, the packing material or container is left to stand or tilted to be filled. Since the liquid falls and the liquid breakage is improved, the filling can be used up easily and the spout can be kept hygienic.

  In addition, by using it on the surface of a product or member having a substantially vertical surface or an angle lower than that, the liquid droplets attached to the surface fall down, and the liquid drainage and antifouling properties can be improved.

  In a second aspect based on the first aspect, the height H of the protrusion and the width w of the concave portion satisfy H / w ≧ 0.7.

  Thereby, it is possible to obtain a molded body excellent in moldability and durability as well as high liquid repellency.

  According to a third invention, in the first or second invention, the height H of the protrusion is 1 μm or more and 50 μm or less.

  Thereby, it is difficult to be influenced by the volume of the liquid droplet, the liquid droplet is prevented from coming into contact with the concave portion, and there is no fear of damage to the structure.

  According to a fourth invention, in any one of the first to third inventions, an imaginary plane passing through a position lowering a distance 0.2 times the height H of the projection from the apex of the projection, The inclination angle of the ridge line of the projection portion with respect to the virtual plane passing through a position that is 8 times lower is 60 ° or more and 90 ° or less.

  By providing the protrusion with an inclination angle, the moldability is improved and it is possible to cope with various manufacturing methods. Further, when the inclination angle is 60 degrees or more, the intrusion of the liquid droplets is suppressed and higher liquid repellency can be exhibited.

  5th invention WHEREIN: The area ratio which the said projection part occupies is 0.2 or less on the virtual plane which passes along the vertex part of the projection part adjacent to a projection part in any one invention of 1-4. It is.

  Thereby, the non-adhesiveness of a base material and a droplet improves further, and higher liquid repellency is exhibited.

  In the sixth invention, in particular, in the molded body of any one of the first to fifth inventions, the planar shape formed by the protrusion is rectangular on a virtual plane passing through the apex of the protrusion adjacent to the protrusion. There is something.

  When the droplet moves through a virtual plane passing through the apex of the protrusion, and the protrusion has a rectangular shape, the number of recesses formed between the protrusions in the movement path of the droplet It can be eliminated or reduced, and since the liquid droplets move quickly along the continuous protrusions, higher liquid repellency can be exhibited. In particular, it is possible to remarkably reduce the risk that droplets enter the recesses formed between the protrusions and the droplets remain on the substrate surface.

  A seventh invention is the invention according to any one of the first to fifth inventions, wherein the falling angle is 45 ° or less.

As a result, higher liquid repellency is exhibited, and even higher effects can be obtained when used on the inner surface of packaging materials or containers, or on the surface of products or members that require antifouling, liquid repellency, and liquid drainage. .
According to an eighth aspect of the invention, particularly in the molded body of any one of the first to seventh aspects, the area ratio occupied by the protrusions is 0.05 or less.

  The non-adhesiveness between the droplet and the substrate is further improved, and even a substrate with a material with relatively low surface energy can exhibit high liquid repellency, thus improving the material selectivity of the molded body. it can.

  A ninth invention is characterized in that, in any one of the first to eighth inventions, the planar shape formed by the protrusion is circular on a virtual plane passing through the apex of the protrusion adjacent to the protrusion. Yes.

  When the droplet moves through a virtual plane passing through the apex of the protrusion, if the protrusion has a polygonal planar shape, the corner of the protrusion existing on the movement path of the droplet interface Droplet movement suppression called a pinning effect occurs by the straight line portion. If the planar shape of the protrusions is a circular shape having no corners or straight portions, the droplets can easily slide on the uneven surface, and higher liquid repellency can be exhibited.

  According to a tenth invention, in any one of the first to ninth inventions, the antifouling coating layer is provided on the surface of the substrate.

By controlling the surface tension of the molded body with the antifouling coating layer, it becomes possible to exhibit higher liquid repellency.

  In an eleventh aspect of the present invention, in any one of the first to tenth aspects, the recess width w is 1 μm or more.

  Thereby, even when the antifouling coating layer is provided, there is little influence on the paintability, and it is possible to ensure transferability at the time of molding.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The molded object in Embodiment 1 of this invention is demonstrated using FIGS. 2 is a cross-sectional view of the molded body, FIGS. 3 and 4 are enlarged cross-sectional views of the concavo-convex surface of the molded body, and FIG. 5 is a plan view of the protrusion on a plane passing through the apex of the protrusion.

  In FIG. 2, a concavo-convex surface 3 having a plurality of regularly arranged protrusions 2 is formed on the surface of a base material of a molded body 1.

  Although the molded object 1 assumes the component structure or film used for the location where liquid repellency is calculated | required, it is not limited to this.

  The material of the base material of the molded body 1 may be any material that can maintain the shape in a durable manner, such as polyethylene, polypropylene, polystyrene, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyamide, vinyl chloride, polylactic acid, polyester, Resins such as polytetrafluoroethylene and cyclic olefins, glasses, metals such as copper and stainless steel are not particularly specified, and are freely taken into consideration in terms of required appearance quality, transparency, mechanical properties, cost, etc. You can choose.

  Further, an additive for imparting required mechanical properties and liquid repellency may be included.

  The molded body 1 and the concavo-convex surface 3 may have an integral structure, but are selected according to the manufacturing method and the required liquid repellency, and may be another material.

  As shown in FIG. 3, the protrusion 2 is a trapezoid or a trapezoidal cone (see FIG. 3A) whose tip surface is a flat surface horizontal to the base material. In addition, it is not limited to this, The substantially trapezoidal cone whose tip surface is a flat surface with an inclination with respect to the base material, and the cone whose end portion of the tip surface is rounded (FIG. 3B) (See FIG. 3 (c)), or a cone with a sharp tip, or a cone with a round tip. Alternatively, the protrusion 2 is a triangular body having a rounded tip. Or the projection part 2 is a substantially triangular body (refer FIG. 4 (a)-(c)) where the front-end | tip part was sharp.

  In addition, the protrusion part 2 is not limited to this, The substantially trapezoid whose front end surface is circular arc shape, and the substantially trapezoid whose front end surface is a flat surface inclined with respect to the base material may be sufficient.

  Further, the uneven surface 3 including the protrusions 2 does not have to be microscopically smooth, and surface roughness and scratches that do not affect the performance are allowed.

In the present embodiment, the height H of the protrusion 2 is defined as follows. When the protrusion 2 has a tip surface (see FIGS. 3A and 3B), it is defined as the distance between the bottom surface of the concave portion of the uneven surface 3 and a virtual plane passing through the tip surface of the protrusion 2. . If the protrusion 2 does not have a tip surface, that is,
When the protrusion 2 includes a tip (see FIG. 3C, FIGS. 4A to 4C), a virtual plane passing through the bottom of the recess of the uneven surface 3 and the tip of the protrusion 2 Is defined as the distance. Note that the above-described virtual plane does not necessarily have to pass through the tip surfaces of all the projections or the tip portions, and at least the tip surfaces of the projections and the two projections adjacent to the projections, or the tips Just go through the department.

  The height H of the protrusions 2 is desirably a constant value for all the protrusions 2. However, variations that are unavoidable in manufacturing are allowed.

  In the present embodiment, the inclination angle of the protrusion 2 is defined as an angle formed by a plane that forms the recess of the uneven surface 3 and the ridge line of the protrusion 2. The ridge line is a line of intersection between an arbitrary plane parallel to the height direction of the protrusion 2 and the side surface of the protrusion 2.

  Although it is desirable that the inclination angle of the protrusion 2 is a constant value for all manufacturing, an imaginary plane passing through a position lowered by 0.2H from the vertex of the protrusion 2 and 0.8H from the vertex of the protrusion 2 If the inclination angle of the ridge line of the protrusion 2 between the virtual plane passing through the lowered position is 60 ° or more and 90 ° or less, it can be arbitrarily changed.

  Further, the ridge line of the protrusion 2 does not need to be a straight line, and can be freely designed in consideration of formability, and may be a curved line or a combined line of a straight line and a curved line. .

  In the present embodiment, the recess width w is defined as the distance between the protrusion 2 on a virtual plane passing through the apex of the protrusion 2 and the protrusion 2 that is closest to and adjacent to the protrusion 2. The vertex part of the projection part 2 is defined as follows. When the protrusion 2 has a tip surface (see FIGS. 3A and 3B), the tip surface is a vertex. When the protrusion 2 does not have a tip surface, that is, when the protrusion 2 has a tip (see FIG. 3C, FIGS. 4A to 4C), 0. The position lowered to the concave side by 5 μm is defined as the apex portion.

  The recess width w is preferably a constant value, but it is in a range where H / w ≧ 0.7 holds between the height H of the protrusion 2 and is arbitrarily variable as long as it is 40 μm or less. Can be done.

  Further, as shown in FIGS. 4A and 4B, the cross-sectional shape (hereinafter referred to as a planar shape) in a virtual plane passing through the apex portion of the protrusion 2 is preferably circular.

  Thereby, a fall angle becomes low and it is possible to improve performance. The planar shape is not limited to this, and may be an ellipse (see FIG. 5C) or a polygon (see FIGS. 5D and 5E).

  Further, as shown in FIG. 5D, the planar shape of the protrusion 2 is more preferably a rectangle.

  Thereby, a fall angle becomes low and it is possible to improve performance. Furthermore, since continuous concave grooves are formed between the protrusions 2, liquid droplets are not captured by the structure of the uneven surface 3, and are difficult to adhere to the uneven surface 3.

When the droplet moves through a virtual plane passing through the apex of the projection, as shown in FIG. 5D, when the projection has a rectangular shape as shown in FIG. The number of the concave portions located in can be eliminated or reduced, and the liquid droplets move quickly along the continuous protrusions, so that higher liquid repellency can be exhibited. In particular, the risk of droplets entering between the protrusions and remaining on the substrate surface can be significantly reduced.

  When the surface is subjected to fine unevenness processing, a method of transferring the shape of the mold having the inverted structure of the desired uneven surface 3 to the surface of the base material is generally used. Die cutting is an issue. However, if the planar shape of the protruding portion 2 is a rectangle, even if the protruding portion has a large height H, it becomes easy to remove the mold along the protruding portion 2 and the moldability is improved.

  Furthermore, when performing injection molding, the draft of a metal mold | die can be made small and the shape design of a molded object becomes easy.

  Furthermore, the planar shapes of the protrusions 2 may or may not all be the same shape.

  In the present embodiment, the area ratio occupied by the protrusions 2 is determined by the protrusions 2 in the entire area where the uneven surface 3 is present on a virtual plane passing through the apex of the protrusions 2. It is defined as the ratio of the area.

  If the area ratio occupied by the protrusions 2 is 0.3 or less, preferably 0.2 or less, more preferably 0.05 or less, different shapes and sizes can be set. In particular, if the area ratio occupied by the protrusions 2 is 0.05 or less, the non-adhesiveness of the droplets with the base material is improved, and even if the base material has a relatively small surface energy, the liquid repellency is high. Therefore, the material selectivity of the molded body can be improved.

  The uneven surface 3 does not need to be disposed over the entire surface of the base material of the molded body 1 and may be disposed only in places where liquid repellency is required.

  The protrusion 2 may be manufactured as a separate part from the molded body, but from the viewpoint of durability, integral molding is desirable. Alternatively, it is desirable that the uneven surface 3 is bonded with good adhesion as the surface of the molded body.

  Next, the manufacturing method of the molded object 1 is demonstrated.

  Although the manufacturing method which provides the uneven | corrugated surface 3 on the surface of the molded object 1 is not specifically limited, The transfer system is mentioned as a method of arranging an unevenness | corrugation regularly with the defined dimension. Examples of the transfer method include injection molding, hot press molding, thermal imprint processing using nanoimprint technology, and optical imprint processing.

  Injection molding is a process in which molten resin is poured into a container (core, cavity) of a mold (mold) whose inner surface is previously provided with an uneven shape, cooled, and the uneven shape on the mold surface is transferred. .

  The hot press molding is a method in which a mold and a resin are heated and the surface unevenness shape is transferred to the resin by pressing the mold against the resin. In particular, a mold having a cylindrical shape and transferring while the cylinder rotates is called embossing roll processing.

  Thermal imprinting is a process in which a thermoplastic resin such as polymethyl methacrylate is applied to a substrate, the temperature is raised above the glass transition temperature, and the mold is pressed to transfer the shape. The resin is cured by applying a photocurable resin to the substrate, pressing the mold and irradiating with UV, and transferring the shape.

  The thermal imprint process has a feature that the selectivity of the thermoplastic resin is wide, but there is a problem that throughput does not increase because it takes time to raise and lower the temperature. On the other hand, although photoimprinting has a problem of selectivity of a photocurable resin, generally, it has a feature of high transferability due to low viscosity and high throughput because it is cured by irradiation with ultraviolet rays.

  Here, the mold can also be produced by mechanical processing such as diamond cutting, special processing such as laser processing, etching, or lithography.

  The molded body 1 of the present embodiment is desirably a molded body having a plurality of protrusions 2 regularly arranged on the surface of the base material, and the protrusions on a virtual plane passing through the apex of the protrusions 2. The area ratio which the part 2 occupies is 0.3 or less, and the height H of the protrusion part 2 and the recessed part width w are formed bodies in which H / w ≧ 0.7.

  It has been conventionally known that a fine uneven structure makes it difficult for droplets to repel and adhere, and it is recognized that the finer the structure, the better the liquid repellency. However, when the concavo-convex structure is formed on the surface of the substrate, there is a concern that the manufacturing risk increases due to the miniaturization and the durability deteriorates.

  As a result of the study, it was found that even if the uneven structure of the order of μm, which is easy to manufacture and has a relatively high durability, has the effect of suppressing the intrusion of liquid droplets by adopting the structure described in the present invention. .

  Here, the regularly arranged protrusions only need to be arranged so as to satisfy the above-described conditions, and the height H and the recess width w of all the protrusions 2 do not have to be constant.

  Furthermore, the virtual plane passing through the apex of the projection 2 refers to a plane including the flat surface when the tip surface of the projection having a truncated cone shape is substantially flat. This includes those in which R processing is applied to the edge of the flat surface. In addition, when the tip of the protrusion is pointed, rounded, or inclined, it passes through the position of 0.5 μm from the position where the height of the protrusion is highest to the substrate side. It was defined as a plane parallel to the substrate. The reason for this setting is that when the tip surface is not substantially flat, the droplet remains in a state of slightly intruding into the recess, and for the 0.5 μm dimension, the experiment used in finding the present invention was used. Determined against the value.

  Further, the area ratio occupied by the protrusions is the area occupied by the protrusions in the entire area where the concavo-convex structure provided on the surface of the substrate exists on the plane passing through the apex of the protrusions. Refers to the percentage.

  Since the droplet is a sphere in the air, the contact angle between the air and the droplet can be considered to be 180 °. For this reason, in the contact surface of a base material and a droplet, it becomes difficult to adhere to a base material, so that the area ratio which a projection part occupies is low. As a result of the examination, it was found that when the area ratio occupied by the protrusions is 0.3 or less, the adhesion between the base material and the droplets is sufficiently lowered and high liquid repellency is exhibited.

  Moreover, the mechanism which H / w which is the value resulting from the height H of a protrusion part and the recessed part width w influences is estimated as follows.

  When a droplet adheres to the surface of the substrate, it first makes point contact, and then follows a path in which the droplet interface wets and spreads along the shape of the substrate surface as shown in FIG.

When the value of H / w corresponding to the aspect ratio of the recess is large, the interface of the droplet needs to work for the potential energy corresponding to the height H while traveling the distance corresponding to the width w. For this reason, when the value of H / w is a certain value or more, as shown in FIG. 5 (b), it is considered that the expansion path of the droplet interface does not follow the uneven shape and moves substantially linearly as shown in FIG. .

  As a result of the examination, if H / w is 0.7 or more, intrusion of liquid droplets into the recesses is suppressed, and high liquid repellency is exhibited.

  It should be noted that the dimensions described in the present invention use a laser microscope for shape measurement or a scanning electron microscope as a measuring apparatus, and allow a deviation of dimension of ± 20% as an error range.

(Modification)
FIG. 7 is a cross-sectional view showing a molded body which is a modification of the first embodiment of the present invention.

  This modification differs from the first embodiment in the presence or absence of the antifouling coating layer 4. For this reason, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 7, the uneven surface 3 is covered with an antifouling coating layer 4.

  The coating agent used for the antifouling coating layer 4 is applied to control the surface free energy of the uneven surface, and the material thereof is not particularly limited, and is fluorine-based, silicone-based, polysilane-based, alkyl-based, An acrylic type, a silica type, etc. can be used. In particular, in order to improve liquid repellency, that is, to reduce surface free energy, those having a fluorocarbon group, a silicone group, a hydrocarbon group, or the like as a functional group of the coating agent component can be used.

  As a fluorine-type coating agent, what contains a fluoroalkyl group, a fluoroether group, etc., a fluorine-type silane compound, and may have a siloxane bond in order to improve film | membrane strength. By including a fluoroether group, it is possible to further reduce the frictional resistance.

  As the silicone-based coating agent, one having polysiloxane as a skeleton and having a methyl group or a phenyl group in a side chain may be used. It may contain a modifying group.

  In addition, polysilanes such as alkyl polysilanes and fluorinated alkyl polysilanes, alkyl-based, acrylic-based, silica-based, and other general-purpose coating agents can be used.

  When applying the coating agent, in order to improve the adhesion to the substrate, for example, a primer that forms a silica layer or an organic layer may be used, and the substrate is subjected to corona treatment or plasma treatment as a pretreatment. The discharge treatment may be performed.

  The film thickness of the coating layer is preferably 30% or less, more preferably 10% or less of the height H of the protrusion 2. This is because if the film thickness of the coating agent is large, the characteristics of the uneven structure of the substrate cannot be exhibited.

  At this time, it is preferable to evaluate the film thickness in the vertical section including the vicinity of the apex of the protrusion, or in the parallel section, not in the recess between the protrusions 2. When a droplet adheres to the surface of the base material, first, since the projection 2 comes into contact, it is preferable to evaluate the film thickness of the coating agent on the projection 2. In addition, when it is difficult to evaluate the film thickness, it is possible to confirm the presence or absence of the coating agent by, for example, analyzing the elements not contained in the base material and contained in the coating agent.

  Furthermore, if the performance of the molded body is not hindered, inorganic fine particles such as silica can be attached to the surface of the molded body to form part of the antifouling coating layer 4. At this time, it is also possible to use a binder component regardless of the inorganic binder / organic binder.

  The coating agent can be applied by a generally known method such as dry or wet.

  The antifouling coating layer 4 is prepared by mixing an additive capable of changing the surface free energy in advance, for example, an additive such as fluorine or silicone, with the base material before molding, and the antifouling coating layer is formed on the surface after molding. May be formed.

  As described above, it can be freely selected in accordance with the droplets that cause contamination, the required durability and appearance.

  Embodiments according to the present invention will be described in more detail below. In addition, this invention is not limited by this Example.

  In each of the examples and comparative examples, an attempt was made to produce a molded article having an uneven surface as shown in FIGS.

  First, a mold having a reversal structure of the concavo-convex surface intended for each example was prepared on the surface of a nickel substrate by a known lithography method.

  Next, an unstretched polypropylene film having a thickness of 100 μm was sandwiched between the mold and a nickel flat plate so that the concavo-convex structure on the mold surface was on the film side, and placed on the lower stage of the hot press.

  Subsequently, the stage is operated while maintaining the lower stage at a temperature not higher than the glass transition temperature of the film, and the upper stage is maintained at a temperature not lower than the glass transition temperature of the film, and is pressed and transferred for a certain time.

  Finally, after natural cooling, the film was peeled off from the mold to obtain a film as a molded body of each example.

  As described above, a molded body having an uneven surface was obtained. When the surface was observed with a scanning electron microscope, it was confirmed that the pattern shape of the master mold was reproduced within the error range even when the dimensional deviation due to thermal shrinkage of the film was taken into consideration.

  Next, in some examples and comparative examples, the uneven surface was provided with a coating that would become an antifouling coating layer.

  As the coating agent, in all Examples and Comparative Examples, a fluorine-based coating agent containing the same fluoroether group was selected, and a pre-coating agent that increased adhesion was also used.

  Next, a method for evaluating liquid repellency on the uneven surface of the molded body is described below.

  As a representative index of liquid repellency, a contact angle and a falling angle of 5 μL of distilled water were selected. A contact angle meter CA-DT type manufactured by Kyowa Interface Science Co., Ltd. was used for measuring the contact angle and the sliding angle.

  Here, the molded body produced as described above has very high non-adhesiveness and may not adhere at all even when the droplet attached to the tip of the syringe needle of the contact angle meter is pressed against the uneven surface. In such a case, since an accurate contact angle cannot be measured, the contact angle was set to 180 degrees.

  The drop angle was 90 degrees or more (indicated as> 90 degrees) when the droplets did not fall even when the uneven surface was vertical.

  Further, whether or not the liquid droplets penetrated into the recesses on the uneven surface of the molded body was observed using a magnifying glass and evaluated as follows.

◯: No liquid intrusion into the recess ×: Liquid intrusion into the recess Here, a method for determining whether or not a liquid droplet has entered the recess will be described. In the state where the droplet is placed on the uneven surface of the molded body or the state where the liquid droplet on the tip of the syringe needle is pressed against the uneven surface, if the shape of the recess is visible from behind, the liquid does not enter the recess. In the case where the concave portion was not visible, it was judged that liquid had entered the concave portion.
Example 1
A molded body having a concavo-convex structure on the substrate surface was produced by the above-described production method. The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. 5C, the planar shape is a square with a side of 5 μm, and the height of the projections By designing so that H = 25 μm and recess width w = 25 μm, a molded body of this example was obtained.

Table 1 shows the results of the evaluation of the liquid repellency of the uneven surface located on the surface of the base material of the molded body.
(Example 2)
The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. 5C, the planar shape is a square with a side of 25 μm, and the height of the projections The design was such that H = 25 μm and the recess width w = 25 μm.

  Furthermore, the compact | molding | casting of a present Example was obtained by apply | coating the said fluorine-type coating agent to the uneven | corrugated surface.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Example 3)
The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. 5A, the planar shape is a circle with a diameter of 5 μm, and the height of the projections By designing so that H = 25 μm and recess width w = 25 μm, a molded body of this example was obtained.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
Example 4
The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. 5B, the planar shape is a circle with a diameter of 25 μm, and the height of the projections By designing so that H = 25 μm and recess width w = 25 μm, a molded body of this example was obtained.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Example 5)
The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. By designing so that the recess width w = 25 μm, the molded body of this example was obtained.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Example 6)
The concavo-convex structure consists of protrusions having a trapezoidal cross section with an inclination angle of 75 degrees. The protrusions are arranged as shown in FIG. 5D, the protrusion width = 5 μm, and the protrusion height H = By designing so that it might be set to 15 micrometers and recessed part width w = 15micrometer, the molded object of the present Example was obtained.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Example 7)
The concavo-convex structure is composed of triangular protrusions having a sharp tip with a cross-sectional angle of 60 degrees as shown in FIG. Further, the protrusions are arranged as shown in FIG. 5D, that is, the planar shape of the protrusion 2 is a rectangle. The molded body of the present example was obtained by designing so that the width of the protruding portion = 0.5 μm, the height of the protruding portion H = 25 μm, and the width of the recessed portion w = 25 μm.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Comparative Example 1)
The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. 5C, the planar shape is a square with a side of 50 μm, and the height of the projections The design was such that H = 15 μm and the recess width w = 15 μm. Furthermore, the molded object of this comparative example was obtained by apply | coating the said fluorine-type coating agent to an uneven surface.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Comparative Example 2)
The concavo-convex structure consists of trapezoidal cone-shaped projections with an inclination angle of 75 degrees, the projections are arranged as shown in FIG. 5C, the planar shape is a square with a side of 50 μm, and the height of the projections By designing such that H = 15 μm and the recess width w = 50 μm, the molded body of this example was obtained.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Comparative Example 3)
Using a flat master mold, a molded body having a smooth substrate surface was produced by the above production method, and a molded body of this comparative example was obtained.

The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.
(Comparative Example 4)
Using a flat master mold, a molded body having a smooth substrate surface was produced by the above-described production method. Furthermore, the molded object of this comparative example was obtained by apply | coating the said fluorine-type coating agent to the smooth surface of a base material.

  The results of evaluating the liquid repellency of the concavo-convex surface located on the surface of the base material of this molded body are also shown in Table 1.

  In Table 1, the area ratio occupied by the protrusions is 0.3 or less, the recess width w between the protrusions and the adjacent protrusions is 40 μm or less, and the drop angle of the droplets located on the substrate surface In the molded body having a 90 ° or less, as shown in Examples 1 to 6, since the liquid droplets adhering to the surface remain in a state where the liquid does not enter the recesses, high liquid repellency can be exhibited. I can do it.

  On the other hand, as shown in Comparative Examples 1 to 4, sufficient liquid repellency cannot be obtained when the area ratio or recess width occupied by the protrusions and the value of the falling angle do not satisfy the conditions described in the present invention. It was.

  As described above, the molded product having liquid repellency due to the fine unevenness formed on the surface according to the present invention exhibits sufficient liquid repellency even when the antifouling coating agent is not used. In addition, because it is excellent in manufacturability and durability, the inner surface of the packaging material, spouts and cap parts that require drainage, vacuum cleaners and refrigerators, air conditioners, washing machines, hot water washing toilet seats, It can be applied to durable consumer goods including household appliances such as microwave ovens and rice cookers, or automobiles and interior and exterior building materials.

DESCRIPTION OF SYMBOLS 1 Molded body 2 Protruding part 3 Uneven surface 4 Antifouling coating layer

Claims (11)

A molded body having a plurality of protrusions regularly arranged on the substrate surface,
On the virtual plane passing through the apex portion of the protrusion adjacent to the protrusion, the area ratio occupied by the protrusion is 0.3 or less, and the distance between the protrusion and the adjacent protrusion on the virtual plane is A recess width w is 40 μm or less,
A molded article, wherein a drop angle of a droplet located on the surface of the substrate is 90 ° or less. The molded body according to claim 1, wherein a height H of the protrusion and a width w of the concave portion satisfy H / w ≧ 0.7. The molded body according to claim 1 or 2, wherein a height H of the protruding portion is 1 µm or more and 50 µm or less. Between the virtual plane that passes through a position that is lowered by 0.2 times the height H of the protrusion from the apex of the protrusion, and the virtual plane that passes through a position that is lowered by 0.8 times the distance The molded body according to any one of claims 1 to 3, wherein an inclination angle of a ridge line of the protrusion is 60 ° or more and 90 ° or less. The area ratio which the said projection part occupies is 0.2 or less on the virtual plane which passes through the vertex part of the projection part adjacent to the said projection part, The Claim 1 characterized by the above-mentioned. Molded body. On a virtual plane passing through the apex of the protrusion adjacent to the protrusion,
The molded body according to any one of claims 1 to 5, wherein a planar shape formed by the protrusions is a rectangle. The molded body according to any one of claims 1 to 6, wherein the sliding angle is 45 ° or less. The molded body according to any one of claims 1 to 7, wherein an area ratio occupied by the protrusions is 0.05 or less on a virtual plane passing through the apex of the protrusions. On a virtual plane passing through the apex of the protrusion adjacent to the protrusion,
The molded body according to any one of claims 1 to 5, wherein a planar shape formed by the protrusion is circular. The molded article according to claim 1, further comprising an antifouling coating layer on the surface of the base material. The said recessed part width w is 1 micrometer or more, The molded object of any one of Claims 1-10 characterized by the above-mentioned.