JP2012020248A - Water repellent coating film, method for manufacturing this film and functional material with water repellent coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a water repellent coating film which can form the water repellent coating film with excellent friction resistance, without requiring a special treatment in bases of various materials and on the surfaces of the bases with various surface structures, as well as a water repellent coating film with excellent friction resistance and a functional material with water repellent coating film.SOLUTION: This method for manufacturing the water repellent coating film includes the following first process and second process: (1) The first process is to form a friction resistant undercoat film by applying a first composition which contains a microparticle (A) with an average particle diameter of 15 to 500 μm, a resin composition (B) and a solvent (C) to at least one surface of the base. In this case, the first composition shows the mass ratio (A:B) of the microparticle (A) to the nonvolatile component of the resin composition (B) being 25:75 to 70:30. (2) The second process is to apply a second composition which contains a hydrophobic microparticle (a) with an average particle diameter of 5 to 500 nm, a resin composition (b) and a solvent (c) to the surface on the opposite side to the base, of the friction resistant undercoat film, then dry the second composition and thus, form a super water-repellent finished film. In this case, the second composition shows the mass ratio (a:b) of the microparticle (a) to the nonvolatile component of the resin composition (b) being 15:85 to 99:1.

Description

  The present invention relates to a method for producing a water-repellent coating film, a water-repellent coating film, and a functional material including the same.

  Conventionally, water repellency is imparted to the surface of a substrate such as metal, glass, paper, cloth, and plastic by chemical treatment such as coating with a fluororesin or a silicone resin. It is known that a water-repellent substrate surface having a water contact angle of about 120 ° can be obtained by coating with a resin.

  Further, the water contact angle becomes 150 ° or more by a method of forming a fine concavo-convex structure on the surface of the base material or a method combining the formation of such a fine concavo-convex structure on the surface of the base material and the above-described coating treatment. Such super water repellency is also imparted to the substrate surface.

  For example, JP-A-3-215570 (Patent Document 1) describes a method for obtaining a coating film comprising a hydrophobic fine powder having a surface tension of 32 dyn / cm or less and a resin having a water absorption of 0.5% or less. A coating film having a water contact angle of 170 ° is disclosed. Japanese Patent Application Laid-Open No. 7-328532 (Patent Document 2) includes at least a surface having hydrophobic particles having an average particle diameter of 1 nm to 1 mm and a resin coating, and the particles have a surface area of 20 of the resin coating. A method for producing a water-repellent coating so as to be exposed and fixed in a region of% or more is disclosed, and a water-repellent coating having a water contact angle of 160 ° or more is disclosed.

  Japanese Patent Application Laid-Open No. 10-259037 (Patent Document 3) describes a method of forming a transparent silica film having an uneven shape on a substrate by heat treatment, and a water repellent coating having a water contact angle of 140 ° or more. Is disclosed. Furthermore, Japanese Patent Application Laid-Open No. Hei 7-97017 (Patent Document 4) has a multi-stage structure including a concavo-convex structure with a large period formed on at least a part of a solid surface and the concavo-convex structure having a concavo-convex structure with a period smaller than the period. And a method of forming a water-repellent surface having a surface area multiplication factor of 5 or more by using machining or electroplating, and discloses a solid having a surface water contact angle of 174 ° or more. ing. Further, JP-A-8-323280 (Patent Document 5) discloses that a reactive monomer or oligomer having a hydrophobic group in a molecule is polymerized by electrolytic oxidation polymerization or the like on the surface of a substrate having electrical conductivity, and a hydrophobic group A water repellency imparting method is described in which a fine concavo-convex structure made of a polymer having a surface is formed on a substrate surface, and a super water repellent surface having a water contact angle of about 150 to 160 ° is disclosed.

  However, in the conventional methods for producing the coating films and the like described in Patent Documents 1 to 5, although water repellency of a water contact angle of 140 ° or more is obtained, the friction resistance is not sufficient, and the degree of rubbing is a little However, it has a problem that water repellency is remarkably lowered, and in order to form a specific fine uneven structure, special processing such as machining, electroplating, and heat treatment is required, There was also a problem that the substrate may be limited.

JP-A-3-215570 JP 7-328532 A Japanese Patent Laid-Open No. 10-259037 Japanese Unexamined Patent Publication No. Hei 7-97017 JP-A-8-323280

  The present invention has been made in view of the above-described problems of the prior art, and has excellent friction resistance without requiring special treatment on base materials of various materials and base materials having various surface structures. An object of the present invention is to provide a method for producing a water-repellent coating film capable of forming a water-repellent coating film, and to provide a water-repellent coating film excellent in friction resistance and a functional material having the same. And

  As a result of intensive studies to achieve the above object, the present inventors have determined the particle size after forming a friction-resistant undercoat film having a concavo-convex structure using large particles having a particle size in a specific range. By forming a super-water-repellent finish film with a finer concavo-convex structure using hydrophobic small particle size particles in the range, a water-repellent coating film with excellent friction resistance can be obtained without requiring special treatment As a result, the present invention has been completed.

That is, the method for producing a water-repellent coating film of the present invention contains fine particles (A) having an average particle size of 15 to 500 μm, a resin composition (B), and a solvent (C). A first composition having a mass ratio (A: B) between A) and the non-volatile content of the resin composition (B) of 25:75 to 70:30 is applied on at least one surface of the substrate. A first step of forming a friction-resistant undercoat;
It contains fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, a resin composition (b), and a solvent (c). The fine particles (a) and the resin composition ( After applying a second composition having a mass ratio (a: b) of 15:85 to 99: 1 to the non-volatile content of b) on the surface of the friction-resistant base film opposite to the substrate. A second step of drying to form a super water-repellent finish film;
It is characterized by including.

Moreover, the water-repellent coating film of the present invention contains fine particles (A) having an average particle diameter of 15 to 500 μm and the non-volatile content of the resin composition (B), and the fine particles (A) and the resin composition ( A friction-resistant base film having a mass ratio (A: B) of B) to the nonvolatile content of 25:75 to 70:30;
Containing fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, formed on the friction-resistant undercoat, and the non-volatile content of the resin composition (b); a super-water-repellent finish film in which the mass ratio (a: b) of a) to the nonvolatile content of the resin composition (b) is 15:85 to 99: 1;
It is characterized by providing.

  Furthermore, the functional material of the present invention is characterized by comprising the water-repellent coating film.

  In the method for producing a water-repellent coating film of the present invention and the water-repellent coating film of the present invention, it is preferable to use fine particles made of a hydrophobic silica compound into which an organosiloxane skeleton is introduced as the fine particles (a).

In the method for producing the water-repellent coating film of the present invention and the water-repellent coating film of the present invention,
The total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant undercoat film is 1 to 80 g / m ² ;
The total supported amount (II) per unit area of the fine particles (a) and the non-volatile content of the resin composition (b) in the super water-repellent finish film is preferably 0.005 to 5 g / m ² .

  Moreover, it is preferable that the quantity ratio (I: II) of such loading amount (I) and loading amount (II) is 100: 0.1-100: 10.

  The reason why the above object is achieved by the present invention is not necessarily clear, but the present inventors infer as follows. That is, in the method for producing a water-repellent coating film of the present invention, the uneven surface formed by the fine particles (A) having a large particle diameter in a specific range is hydrophobic, and the small particle diameter in a specific range is hydrophobic. Since the fine particles (a) are uniformly covered, a water-repellent coating film that exhibits super water repellency is obtained by the fine uneven structure and the hydrophobicity of the fine particles (a). When the water-repellent coating film thus obtained is rubbed, the fine particles (a) adhering to the vicinity of the projections formed by the fine particles (A) on the film surface may peel off, but most of them Since the fine particles (a) remain in the concave portions formed by the fine particles (A) and do not peel off, the uneven structure formed by the hydrophobic fine particles (a) is maintained even after friction, and the high water repellency is maintained. The present inventors speculate that this is possible.

  In the method for producing a water-repellent coating film of the present invention, the base film is formed before the super-water-repellent finish film is formed. In this case, it is possible to form a uniform finish film without requiring any special treatment, and furthermore, by such a two-layer structure, a water-repellent coating film is formed on the surface of the substrate having low solvent resistance. The inventors speculate that even in the formation, it is possible to suppress a decrease in the water repellency of the finished film due to the eluate from the substrate surface.

  According to the present invention, it is possible to form a water-repellent coating film having excellent friction resistance on a substrate surface of various materials and a substrate surface having various surface structures without requiring special treatment. It is possible to provide a method for producing an aqueous coating film, and to provide a water-repellent coating film excellent in friction resistance and a functional material including the same.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

First, the manufacturing method of the water-repellent coating film of the present invention will be described. The method for producing a water-repellent coating film of the present invention comprises fine particles (A) having an average particle diameter of 15 to 500 μm, a resin composition (B), and a solvent (C), and the fine particles (A) The first composition having a mass ratio (A: B) of 25:75 to 70:30 with respect to the nonvolatile content of the resin composition (B) is applied on at least one surface of the base material and is resistant to friction. A first step of forming a conductive underlayer;
It contains fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, a resin composition (b), and a solvent (c). The fine particles (a) and the resin composition ( After applying a second composition having a mass ratio (a: b) of 15:85 to 99: 1 to the non-volatile content of b) on the surface of the friction-resistant base film opposite to the substrate. A second step of drying to form a super water-repellent finish film;
It is characterized by including. Hereinafter, the method for producing a water-repellent coating film of the present invention will be described by dividing it into a first step and a second step.

(First step: Friction resistant underlayer forming step)
The first step includes fine particles (A) having an average particle diameter of 15 to 500 μm, a resin composition (B), and a solvent (C). The fine particles (A) and the resin composition ( A first composition having a mass ratio (A: B) with a non-volatile content of B) of 25:75 to 70:30 is applied on at least one surface of the base material to form a friction-resistant base film. It is a process.

  The fine particles (A) used in the first step are for forming a concavo-convex structure on the substrate surface with the fine particles. Examples of such fine particles (A) include acrylic resins, styrene resins, benzoguanamine / melamine resins, urethane resins, phenol resins, polyethylene resins, polystyrene resins, fluorine resins, silicone resins, and the like. Organic materials, activated carbon; silicates; metal oxides such as alumina, hydrophilic silica, hydrophobic silica, zirconia; diatomaceous earth; inorganic materials such as glass, and composite materials composed of such organic materials and inorganic materials. Can be mentioned. Among these materials, it is preferable to use an organic material or an inorganic material from the viewpoint of the hydrophobicity and hardness of the particles. As the organic material, silicone resins, fluorine resins, polyethylene resins, and polystyrene resins are preferable. Fine particles made of resin, fluororesin, polyethylene resin, or polystyrene resin are more preferable. Moreover, as an inorganic material, hydrophobic silica and alumina are preferable. The fine particles made of these materials may be used alone or in combination of two or more.

  Such fine particles are available as commercial products. For example, X-52-875 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Trefill R-900 (manufactured by Toray Dow Corning Co., Ltd.), which are fine particles made of silicone resin. ); Granular white birch WHA (manufactured by Nippon Enviro Chemicals Co., Ltd.) which is fine particles made of activated carbon; LPS-300C (manufactured by Lignite Co.) which is fine particles made of phenol resin.

  The average particle size of the fine particles (A) needs to be in the range of 15 to 500 μm. When the average particle diameter is less than the lower limit, the formation of the uneven structure on the surface of the friction-resistant base film is insufficient, and the super-water-repellent finish film is peeled off due to friction, whereas when the upper limit is exceeded, the resin composition Fixing the fine particles (A) by (B) becomes difficult, and the friction resistance of the friction-resistant base film is lowered, and the range of friction near the top of the convex portion formed by the fine particles (A) is widened. The super water-repellent finish film is easily peeled off by friction, and the friction resistance is lowered. In addition, the average particle diameter of such fine particles (A) is preferably 15 to 200 μm and more preferably 15 to 100 μm because higher effects tend to be obtained from the same viewpoint. . The particle size of such fine particles (A) can be measured using a laser diffraction type / scattering type particle size distribution measuring apparatus.

  The resin composition (B) used in the first step functions as a binder for supporting the fine particles (A) on the surface of the substrate. Such a resin composition may be composed only of a resin component, or may be a solution or an emulsified dispersion composed of a resin component and a solvent. Although it does not restrict | limit especially as said resin component, For example, silicone resin, an acrylic resin, vinyl acetate resin, a urethane resin, a polyurethane resin, an epoxy resin, a melamine resin, and resin which combined these 2 or more are mentioned. Among these resin components, a silicone resin, an acrylic resin, a polyurethane resin, and an epoxy resin are preferable from the viewpoint of friction resistance and water repellency, and a polyurethane resin and an epoxy resin are particularly preferable. Examples of the solvent include water and organic solvents. Examples of the organic solvent include aliphatic alcohols having 1 to 8 carbon atoms such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, hexyl alcohol, and 2-ethylhexyl alcohol. Hydrocarbons such as n-hexane, isohexane, cyclohexane, methylcyclohexane, n-heptane, isooctane, n-decane, mineral terpene, turpentine oil, isoparaffin, toluene, xylene, solvent naphtha; acetone, methyl ethyl ketone, methyl isobutyl ketone, Ketones such as diisobutyl ketone, cyclohexanone, diacetone alcohol; esters such as ethyl acetate, methyl acetate, butyl acetate, methyl lactate, and ethyl lactate; diethyl ether, diisopropyl ether , Methyl cellosolve, ethyl cellosolve, butyl cellosolve, dioxane, methyl tertiary butyl ether, butyl carbitol and other ethers; ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and other glycols; diethylene glycol monomethyl ether, triethylene glycol monomethyl ether And glycol ethers such as propylene glycol monomethyl ether and 3-methoxy-3-methyl-1-butanol; glycol esters such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate. Furthermore, such a resin composition may contain additional components such as a curing agent and a catalyst as necessary. When these additive components are contained, the additive component is preferably 10 parts by mass or less with respect to 100 parts by mass of the resin component. In the present invention, the non-volatile content of the resin composition (B) means a component in the resin composition (B) that remains without volatilization in the water-repellent coating film obtained by the present invention. The component and the additive component added as needed correspond.

  Such a resin composition is available as a commercial product, for example, KR-400 (manufactured by Shin-Etsu Chemical Co., Ltd., silicone resin), X-7096 (manufactured by Nikka Chemical Co., Ltd., urethane resin), neo sticker 1700 (manufactured by Nikka Chemical Co., Ltd., polyurethane resin), Territic GC-100B (manufactured by Glow Chemical Co., epoxy resin), UNIKA RESIN 380-K (manufactured by Union Chemical Industries, Ltd., melamine resin). .

  The solvent (C) used in the first step is a solvent that functions as a dispersion medium for dispersing the fine particles (A) and the resin composition (B). Although it does not specifically limit as said solvent, A substantially inert thing is preferable and water and an organic solvent are mentioned. Examples of the organic solvent include aliphatic alcohols having 1 to 8 carbon atoms such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, hexyl alcohol, and 2-ethylhexyl alcohol; n-hexane, isohexane, cyclohexane, methylcyclohexane, and n-heptane. , Hydrocarbons such as isooctane, n-decane, mineral turpentine, turpentine oil, isoparaffin, toluene, xylene, solvent naphtha; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, diacetone alcohol; ethyl acetate , Esters such as methyl acetate, butyl acetate, methyl lactate, ethyl lactate; diethyl ether, diisopropyl ether, methyl cellosolve, ethyl cellosolve, butyl Ethers such as losolve, dioxane, methyl tertiary butyl ether, butyl carbitol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol; diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, 3- Examples include glycol ethers such as methoxy-3-methyl-1-butanol; glycol esters such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate. As such a solvent, 1 type may be used independently or 2 or more types may be used together, and it can select suitably according to a base material or the said resin composition (B). Moreover, the acid and / or alkali etc. as a pH adjuster may further be included.

  The first composition (friction-resistant undercoat film forming composition) used in the first step contains the fine particles (A), the resin composition (B), and the solvent (C). .

  In said 1st composition, mass ratio (A: B) of microparticles | fine-particles (A) and the non volatile matter of a resin composition (B) is 25: 75-70: 30. Since the amount of the fine particles (A) that make the substrate surface uneven and the amount of the resin composition (B) that further improves the friction resistance can be obtained, a friction-resistant undercoat film having excellent friction resistance can be obtained. If the mass ratio of the fine particles (A) to the nonvolatile content of the resin composition (B) is less than the lower limit, the fine particles (A) are buried in the resin composition (B), and a good uneven structure cannot be formed. When the upper limit is exceeded, the fine particles (A) easily fall off from the base film due to friction or the like, and a good friction-resistant base film cannot be formed. Further, such a mass ratio (A: B) is preferably 30:70 to 60:40 because a higher effect tends to be obtained from the same viewpoint.

  Further, the content of the fine particles (A) in the first composition is preferably 1 to 50% by mass, particularly preferably 1 to 40% by mass in the first composition. If the content of the fine particles (A) is less than the above lower limit, the formation of the concavo-convex structure on the surface of the friction-resistant undercoating film tends to be insufficient, and the friction resistance tends to be lowered. On the other hand, the content of the fine particles (A) When the value exceeds the upper limit, it becomes difficult to fix the fine particles (A) with the resin composition (B), and the friction resistance tends to decrease.

  In the first composition, the blending amount of the solvent (C) is not particularly limited and is appropriately selected according to the coating method to be employed, etc., and is 10 to 95% by mass in the first composition. It is preferable.

  In addition to the fine particles (A), the resin composition (B), and the solvent (C), the first composition includes additives such as an ultraviolet absorber, an antioxidant, an antiseptic, and an antifungal agent depending on the purpose. May further be contained. When such an additive is contained, the content of the additive is preferably 3% by mass or less in the first composition.

  The method for obtaining the first composition is not particularly limited, but from the viewpoint of forming a uniform concavo-convex structure, the first composition contains the fine particles (A), the resin composition (B) and the solvent (C). A method of mixing so as to contain as a uniform dispersion is preferable. For example, a method of mixing the fine particles (A), the resin composition (B), and the solvent (C) with a homomixer or the like is preferable.

  In the first step according to the present invention, the first composition is applied onto at least one surface of a substrate to form a friction-resistant undercoat film. The substrate is not particularly limited, and for example, a substrate made of various materials such as glass, metal, paper, ceramics, cement material, synthetic resin, fiber, and painted surface, and a substrate having various surface structures. Can be mentioned.

  In order to obtain better friction resistance in the water-repellent coating film of the present invention, the surface of the base material is cleaned before the first composition is applied, and organic matter is contaminated from the surface of the base material. It is preferable to remove the substance substantially. The cleaning method is not particularly limited, and may vary depending on the material of the base material. For example, it is preferable to perform cleaning with a solvent using an organic solvent such as acetone or ethanol.

  The method for applying the first composition is not particularly limited, and a conventional application method can be appropriately employed. Examples of such application methods include brush coating, coating with an air gun or an airless gun coating machine; spray coating in the form of aerosol spray or trigger spray; dip coating; flow coating; spin coating; bar coating; roll coating, and the like. It is done.

The amount of the first composition applied per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant base film of the dried water-repellent coating film obtained according to the present invention. The coating amount is preferably such that the total supported amount (I) is 1 to 80 g / m ^2, and more preferably 5 to 50 g / m ² . If the coating amount is less than the lower limit, the coating amount is too small and it tends to be difficult to obtain a base film having good friction resistance. In addition, the thick coating tends to cause cracks in the rubbing resistant base film.

  In the first step according to the present invention, the first composition is preferably dried after the application from the viewpoint of facilitating adhesion of the fine particles (a) to the uneven surface formed by the fine particles (A). It does not specifically limit as said drying method, In this invention, it is also possible to dry without heating. That is, in the conventional method for producing a water-repellent coating film, heating is generally required, but when the first composition in the present invention is used, the same effect can be obtained by drying at room temperature. . In addition, it is preferable to dry at about 60-180 degreeC for about 5 to 60 minutes from a viewpoint of shortening the time which forms a friction-resistant base film more.

(Second step: Super water-repellent finish film forming step)
The second step includes fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, a resin composition (b), and a solvent (c), and the fine particles (a) And a second composition having a mass ratio (a: b) of 15:85 to 99: 1 of the non-volatile content of the resin composition (b) on the side opposite to the base material of the friction-resistant base film It is a step of forming a super-water-repellent finish film by applying it on the surface and then drying it.

  The fine particles (a) used in the second step are hydrophobic fine particles for forming a super water-repellent fine uneven structure on the outermost surface of the water-repellent coating film. Examples of such fine particles (a) include hydrophobic or hydrophobic organic materials such as silicone resins, fluororesins, polyethylene resins, and polystyrene resins, hydrophobic materials such as hydrophobic silica and alumina, or Hydrophobized inorganic materials and composite materials composed of such organic materials and inorganic materials can be mentioned. Among these materials, it is particularly preferable to use a hydrophobic silica compound into which an organosiloxane skeleton is introduced from the viewpoint of developing super water repellency. As fine particles made of these materials, one kind may be used alone, or two or more kinds may be used in combination.

  Such fine particles are available as commercial products, and examples thereof include fine particles made of silica hydrophobized and surface treated with hexamethyldisilazane, dimethyldichlorosilane, or the like. Fine particles made of silica hydrophobized and surface-treated with hexamethyldisilazane include Aerosil RX-50, Aerosil RX-200, Aerosil RX-300 (manufactured by Nippon Aerosil Co., Ltd.), Leoroseal ZD-30ST, Leoroseal HM- 20L, Reolosil HM-30S (manufactured by Tokuyama Corporation). Examples of the fine particles comprising silica hydrophobized and surface-treated with dimethyldichlorosilane include Aerosil R974 and Aerosil R976 (manufactured by Nippon Aerosil Co., Ltd.).

  The average particle diameter of the fine particles (a) needs to be in the range of 5 to 500 nm. If the average particle size is less than the lower limit, fine particles are too fine to form an appropriate uneven structure for expressing super water repellency, making it difficult to develop super water repellency. In this case, a uniform film cannot be formed, and it becomes difficult to develop super water repellency. In addition, the average particle size of such fine particles (a) is preferably 50 to 300 nm, more preferably 50 to 200 nm because higher effects tend to be obtained from the same viewpoint. The particle diameter of such fine particles (a) can be measured using a laser diffraction type / scattering type particle size distribution measuring apparatus.

  The resin composition (b) used in the second step functions as a binder for supporting the fine particles (a) on the surface of the friction-resistant base film. Such a resin composition may be composed of only a resin component or a solution composed of a resin component and a solvent. The resin component is not particularly limited, and examples thereof include silicone resins, acrylic resins, vinyl acetate resins, polyurethane resins, epoxy resins, melamine resins, alkylphenol resins, rosin ester resins, and resins obtained by combining two or more of these. . Among these resin components, silicone resin, acrylic resin, polyurethane resin, epoxy resin, alkylphenol resin, and rosin ester resin are preferable from the viewpoint of friction resistance and water repellency. Moreover, an organic solvent is mentioned as said solvent, As said organic solvent, the thing similar to what was mentioned as an organic solvent in the said resin composition (B) is mentioned, for example. Such a resin composition may further contain additional components such as a curing agent and a catalyst as necessary. When these additive components are contained, the additive component is preferably 10 parts by mass or less with respect to 100 parts by mass of the resin component. In the present invention, the nonvolatile content of the resin composition (b) means a component in the resin composition (b) that remains without volatilization in the water-repellent coating film obtained by the present invention, and is usually a resin. The component and the additive component added as needed correspond.

  Such a resin composition is available as a commercial product. For example, SH8011 (manufactured by Toray Dow Corning Co., Ltd., silicone resin), Accusol 820 (manufactured by Rohm and Haas Co., Ltd., acrylic resin), Tamanol 100S ( Arakawa Chemical Industries, Ltd., alkylphenol resin), Pencel D-125 (Arakawa Chemical Industries, rosin ester resin).

  The solvent (c) used in the second step is a solvent that functions as a dispersion medium for dispersing the fine particles (a) and the resin composition (b), and is preferably an organic solvent. It does not specifically limit as said organic solvent, The organic solvent similar to the organic solvent quoted by the said solvent (C) can be used. As such a solvent, 1 type may be used independently or 2 or more types may be used together, and it can select suitably according to a friction-resistant base film and the said resin composition (b). Moreover, the acid and / or alkali etc. as a pH adjuster may further be included.

  The second composition (super water-repellent finish film-forming composition) used in the second step contains the fine particles (a), the resin composition (b), and the solvent (c). .

  In said 2nd composition, mass ratio (a: b) of microparticles | fine-particles (a) and the non volatile matter of a resin composition (b) is 15: 85-99: 1. The superb surface having excellent friction resistance due to the balance between the amount of fine particles (a) that make the outermost surface of the coating film super water-repellent fine irregularities and the amount of the resin composition (b) that further improves the friction resistance. Since a water-repellent finish film is obtained, if the mass ratio of the fine particles (a) to the non-volatile content of the resin composition (b) is less than the lower limit, the fine particles (a) are buried in the resin composition (b) and a good uneven structure On the other hand, if the upper limit is exceeded, the fine particles (a) easily fall off from the finished film due to friction or the like, and a good super water-repellent finished film cannot be formed. In addition, such a mass ratio (a: b) is preferably 50:50 to 90:10 from the viewpoint of obtaining a higher effect from the same viewpoint, and is preferably 60:40 to 80: More preferably, it is 20.

  In addition, the content of the fine particles (a) in the second composition is preferably 1 to 50% by mass and particularly preferably 1 to 40% by mass in the second composition. When the content of the fine particles (a) is less than the above lower limit, the formation of the uneven structure on the surface of the super water-repellent finish film tends to be insufficient, and the super water repellency tends to be lowered, while the content of the fine particles (a) is low. When the upper limit is exceeded, the effect of improving water repellency associated with the increase in fine particles (a) tends to decrease.

  In the second composition, the blending amount of the solvent (c) is not particularly limited and is appropriately selected depending on the coating method to be employed, etc., and is 10 to 99% by mass in the second composition. It is preferable.

  In addition to the fine particles (a), the resin composition (b) and the solvent (c), the second composition further contains an ultraviolet absorber, an antioxidant, an antiseptic, an antifungal agent and the like depending on the purpose. You may do it. When such an additive is contained, the content of the additive is preferably 3% by mass or less in the second composition.

  The method for obtaining the second composition is not particularly limited, but the second composition contains the fine particles (a), the resin composition (b) and the solvent (c) as a uniform dispersion thereof. For example, a method in which the fine particles (a), the resin composition (b), and the solvent (c) are mixed and then the fine particles (a) are finely dispersed by a fine particle treatment is preferable. When aggregated fine particles are mixed due to poor dispersion of the fine particles (a), the super water repellency and friction resistance of the super water repellent finish film tend to be lowered. The fine particle treatment is not particularly limited, and a method of dispersing fine particles by using a homogenizer, an optimizer, a nanomizer, a colloid mill, a bead mill, a sand mill, a homomixer, and an ultrasonic homogenizer alone or in combination of two or more. Is mentioned.

  In the second step according to the present invention, the second composition is applied onto the surface of the friction-resistant base film opposite to the substrate and then dried to form a super water-repellent finish film.

  The method for applying the second composition is not particularly limited, and a method similar to the method exemplified in the method for applying the first composition can be appropriately employed.

The amount of the second composition applied per unit area of the fine particles (a) and the nonvolatile content of the resin composition (b) in the super-water-repellent finish film of the dried water-repellent coating film obtained according to the present invention. The coating amount is preferably such that the total supported amount (II) is 0.005 to 5.0 g / m ^2, and more preferably 0.01 to 1.0 g / m ² . If the coating amount is less than the lower limit, the coating amount is too small and it tends to be difficult to obtain a film that exhibits super water repellency. On the other hand, if the upper limit is exceeded, the improvement rate of super water repellency is small and economical. At the same time, the super-water-repellent finish film tends to peel off due to the thick coating.

  In the second step according to the present invention, the drying method of the second composition is not particularly limited as long as the solvent volatilizes, and is dried without heating as in the drying method mentioned in the first step. It is also possible to adopt a method to do this. In addition, it is preferable to dry at about 60-180 degreeC for about 5 to 60 minutes from a viewpoint of shortening the time which forms a super-water-repellent finish film more.

  As described above, the above-described production method contains the fine particles (A) and the non-volatile content of the resin composition (B), and is obtained as a non-volatile content of the first composition. A water-repellent coating film comprising the non-volatile content of the resin composition (b) and obtained as the non-volatile content of the second composition and having a super-water-repellent finish film formed on the friction-resistant undercoat film is obtained. It is done.

  In the method for producing a water-repellent coating film of the present invention, the total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant base film, The ratio (I: II) of the total supported amount (II) per unit area between the fine particles (a) and the non-volatile content of the resin composition (b) in the water-repellent finish film is 100: 0.1 to 100: 10 It is preferable that it is the range of these. If the ratio of the supported amount (II) to the supported amount (I) is less than the lower limit, the super water-repellent finish film tends to exhibit insufficient super water repellency and the water repellency after friction tends to decrease. On the other hand, if the upper limit is exceeded, it tends to be difficult to maintain the water repellency after friction.

Next, the water repellent coating film of the present invention will be described. The water-repellent coating film of the present invention contains fine particles (A) having an average particle size of 15 to 500 μm and the non-volatile content of the resin composition (B), and the fine particles (A) and the resin composition (B). A friction-resistant undercoat film having a mass ratio (A: B) to a nonvolatile content of 25:75 to 70:30,
Containing fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, formed on the friction-resistant undercoat, and the non-volatile content of the resin composition (b); a super-water-repellent finish film in which the mass ratio (a: b) of a) to the nonvolatile content of the resin composition (b) is 15:85 to 99: 1;
It is characterized by providing.

  Although the manufacturing method of the water-repellent coating film of this invention is not specifically limited, For example, it can obtain by the manufacturing method of the water-repellent coating film of this invention mentioned above.

  As the fine particles (A), resin composition (B), fine particles (a) and resin composition (b) used in the present invention, fine particles (A), resin compositions ( B), fine particles (a), and resin compositions (b) can be the same as those mentioned above.

  Further, in the friction-resistant base film according to the present invention, the mass ratio (A: B) between the fine particles (A) and the non-volatile content of the resin composition (B) and the non-volatile of the fine particles (A) and the resin composition (B). The total carrying amount (I) per unit area per minute is as described above.

  In the friction-resistant undercoat according to the present invention, the content of the fine particles (A) is the same as the content of the fine particles (A) in the first composition in the method for producing a water-repellent coating film described above. It is preferable that it is 25-70 mass% in a friction-resistant base film, and it is especially preferable that it is 30-60 mass%.

  Further, in the super water-repellent finish film according to the present invention, the mass ratio (a: b) between the fine particles (a) and the non-volatile content of the resin composition (b) and the non-volatile of the fine particles (a) and the resin composition (b). The total loading (II) per unit area per minute is as described above.

  In the super water-repellent finish film according to the present invention, the content of the fine particles (a) is the same as the content of the fine particles (a) in the second composition in the method for producing a water-repellent coating film described above. It is preferable that it is 15-99 mass% in a super-water-repellent finish film, It is more preferable that it is 50-90 mass%, It is especially preferable that it is 60-80 mass%.

  In the water-repellent coating film of the present invention, the total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant undercoat film, and the super-water-repellent film The mass ratio (I: II) of the total supported amount (II) per unit area between the fine particles (a) and the non-volatile content of the resin composition (b) in the finished film is as described above.

  Next, the functional material of the present invention will be described. The functional material of the present invention includes the water-repellent coating film of the present invention.

  The method for producing the functional material of the present invention is not particularly limited. For example, the above-described water-repellent coating film of the present invention is formed on the surface of the same substrate as described in the above-described method of producing the water-repellent coating film of the present invention. Can be obtained.

  Since the water-repellent coating film of the present invention can impart frictional water repellency to various substrates as described above, it is specifically super water-repellent, antifouling, waterproof, snowproof, and iceproof. Various functional materials of the present invention exhibiting functions such as frost prevention, rust prevention, algae prevention, antibacterial, and mold prevention can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

  In each Example and Comparative Example, the particle diameters of the fine particles (A) and the fine particles (a) are measured by a laser diffraction type / scattering type particle size distribution measuring device (product name “LA-920”, manufactured by Horiba, Ltd.). The particle diameter (median particle diameter) having a percentage integrated value of 50% was defined as the average particle diameter (μm or nm). The resin composition (B) and the non-volatile content (parts by mass) of the resin composition (b) were prepared by using 5 g of each resin composition in an oven (product name “Perfect Oven SPH-201”, manufactured by ESPEC Corporation). It was converted from the ratio (mass%) of non-volatile content in each resin composition calculated from the residual amount (g) after heating at 105 ° C. for 3 hours. In Examples and Comparative Examples, “parts” means “parts by mass” unless otherwise specified.

  In addition, the following water contact angle evaluation test, water repellency evaluation test, and friction resistance evaluation test were performed using the coating films obtained in the examples and comparative examples as samples.

<Evaluation test of water contact angle>
Using a portable contact angle meter (product name “PG-X”, manufactured by Matsubo Co., Ltd.), the static contact angle of water on the sample surface was measured with a distilled water dropping amount of 2.5 μL.

<Water repellency evaluation test>
The following water drop test and water drop mobility test were carried out to evaluate the water repellency of the sample surface.

a. Water Drop Test A few drops of water were dropped on a line across the sample surface placed horizontally, the contact angle of these water droplets was measured, and the water repellency of the sample surface was evaluated based on the following criteria.
A: There are mainly water droplets that are gathered, close to a true sphere, and brilliantly shining, and have an excellent contact angle of 145 ° or more.
B: There are mainly brilliant water droplets that are slightly spread, slightly deviated from the true sphere, and have a good contact angle of 140 ° or more and less than 145 °.
C: Spreading, flat, small water droplets are mainly present and have a contact angle of less than 140 °.

b. Water drop mobility test Following the water drop test, the edge of the sample at a position parallel to a plurality of water drop lines placed on the sample surface was slowly lifted. The angle at which the water droplets began to flow on the tilted surface or the height of the lifted edge from the horizontal support surface was measured. The smaller the angle or the height of the edge portion, the better the water repellency and contact angle of the sample surface, and evaluation was performed based on the following criteria.
A: Inclination of 0 ° or more and less than 10 ° (edge height of 0 or more and less than 2 cm)
B: Inclination of 10 ° or more and less than 20 ° (edge height of 2 or more and less than 3.5 cm)
C: Inclination of 20 ° or more and less than 30 ° (edge portion height of 3.5 or more and less than 5 cm)
D: Inclination of 30 ° or more (edge height of 5 cm or more).

<Evaluation test for friction resistance>
After conducting the friction test, the water contact angle evaluation test and the water repellency evaluation test were performed to evaluate the water repellency of the sample surface after the friction test. The friction test is based on JIS L-8049, using a Gakushin type friction tester (product name "Friction Tester Standard", manufactured by Showa Heavy Machinery Co., Ltd.), with a load of 200 g, a contact surface made of nylon cloth, reciprocating slide The number of dynamic exercises was 100.

  In each example and comparative example, the following were used as the fine particles (A), the resin composition (B), the fine particles (a), and the resin composition (b), respectively.

<Fine particles (A)>
(A) -1 X-52-875 (manufactured by Shin-Etsu Chemical Co., Ltd.)
Silicone resin (nonvolatile content: 100% by mass)
(A) -2 LPS-300C (manufactured by Lignite Co., Ltd.)
Phenolic resin (nonvolatile content: 100% by mass)
(A) -3 Granular white birch WHA (manufactured by Nippon Enviro Chemicals)
Activated carbon (nonvolatile content: 100% by mass)
(A) -4 Trefil R-900 (manufactured by Toray Dow Corning)
Silicone resin (nonvolatile content: 100% by mass)
(A) -5 Spherical white rabbit X7100H (manufactured by Nippon Enviro Chemicals)
Activated carbon (nonvolatile content: 100% by mass)
(A) -6 Trefil R-902A (manufactured by Toray Dow Corning Co., Ltd.)
Silicone resin (nonvolatile content: 100% by mass).

<Resin composition (B)>
(B) -1 X-7096 (manufactured by Nikka Chemical Co., Ltd.)
Urethane resin emulsion (nonvolatile content: 38% by mass)
(B) -2 Neo Sticker 1700 (manufactured by Nikka Chemical Co., Ltd.)
Ester polyurethane resin emulsion (nonvolatile content: 38% by mass)
(B) -3 KR-400 (manufactured by Shin-Etsu Chemical Co., Ltd.)
Silicone resin (nonvolatile content: 100% by mass)
(B) -4 Territic GC-100A (Glow Chemical Co., Ltd.)
Curing agent (nonvolatile content: 17% by mass)
Territic GC-100B (Glow Chemical Co., Ltd.)
Epoxy resin (nonvolatile content: 46% by mass)
(B) -5 UNIKA RESIN 380-K (manufactured by Union Chemical Industries, Ltd.)
Melamine resin (nonvolatile content: 80% by mass)
UNIKA CATALYST 3-P (manufactured by Union Chemical Industries)
Catalyst (nonvolatile content: 42% by mass).

<Fine particles (a)>
(A) -1 Leoroseal ZD-30ST (manufactured by Tokuyama Corporation)
Organosiloxane modified silica (nonvolatile content: 100% by mass)
(A) -2 Aerosil RX-50 (Nippon Aerosil Co., Ltd.)
Organosiloxane-modified silica (nonvolatile content: 100% by mass).

<Resin composition (b)>
(B) -1 SH8011 (made by Toray Dow Corning Co., Ltd.)
Silicone resin (nonvolatile content: 50% by mass)
(B) -2 Accusol 820 (Rohm and Haas Co., Ltd.)
Acrylic resin (nonvolatile content: 100% by mass)
(B) -3 Tamanoru 100S (Arakawa Chemical Industries, Ltd.)
Alkylphenol resin (nonvolatile content: 100% by mass)
(B) -4 Pencel D-125 (Arakawa Chemical Industries, Ltd.)
Rosin ester resin (nonvolatile content: 100% by mass).

Example 1
First, (A) -1 (5 parts) as fine particles (A), (B) -1 (20 parts (7.5 parts in terms of mass of nonvolatile content)), isopropyl alcohol (45) as resin composition (B) Part) and ion-exchanged water (30 parts) are premixed, and then subjected to a stirring process (10 minutes) with a homomixer (product name “TK HOMODISPER”, manufactured by Tokushu Kika Kogyo Co., Ltd.). A white liquid first composition having a content of 12.5% by mass was obtained. The average particle diameter of the obtained fine particles (A) was 40 μm.

  Next, after premixing (a) -1 (1 part) as fine particles (a), (b) -1 (0.5 parts) and isopropyl alcohol (98.5 parts) as the resin composition (b), A semi-transparent liquid second composition having a non-volatile content of 1.5 mass% by subjecting to fine particle treatment (1 minute) with an ultrasonic homogenizer (product name “US-600T”, manufactured by Nippon Seiki Seisakusho Co., Ltd.) I got a thing. The average particle diameter of the obtained fine particles (a) was 160 nm.

  Next, a commercially available glass plate (12 cm × 12 cm) was prepared as a substrate. The glass plate surface was washed with acetone to remove the residue.

Next, the first composition is subjected to an auto film applicator (product name “PI-1210”, manufactured by Tester Sangyo Co., Ltd.) and the fine particles (A) and the resin composition in the friction-resistant base film after forming the coating film. The base material was coated on one side of the base material so that the total supported amount per unit area with the nonvolatile content of (B) was 15 g / m ^2, and dried at 105 ° C. for 10 minutes to form a friction-resistant base film. .

In the super-water-repellent finish film after forming the coating film on the obtained friction-resistant undercoat film with the trigger spray (product name “TS800-1”, manufactured by Enomoto Kogyo Co., Ltd.) A super-water-repellent finish film was applied by coating so that the total supported amount per unit area of the fine particles (a) and the non-volatile content of the resin composition (b) was 0.15 g / m ² and drying at room temperature for 20 minutes. A water-repellent coating film was obtained.

(Examples 2 to 25 and Comparative Examples 1 to 9)
The combination of the fine particles (A), the resin composition (B), the fine particles (a) and the resin composition (b) used in Example 1 was replaced with the combinations shown in Tables 1 to 6 below. In the same manner as Example 1, coating films of Examples 2 to 25 and Comparative Examples 1 to 9 were obtained.

  Tables 1 to 6 below collectively show the compositions and evaluation results of the coating films obtained in Examples 1 to 25 and Comparative Examples 1 to 9. In Tables 1 to 6, * 1 is “total supported amount per unit area of the fine particles (A) and the non-volatile content of the resin composition (B)”, and * 2 is “fine particles (a) and the resin composition (b)”. The total supported amount per unit area with the non-volatile content of ".

  As is apparent from the evaluation results of Examples 1 to 25 shown in Tables 1 to 4, the water-repellent coating film obtained by the method for producing a water-repellent coating film of the present invention is in contact with water before the friction test. It was confirmed that the angle was 150 ° or more and it had super water repellency. These water-repellent coating films also showed good results in the water drop test and the water drop mobility test. Furthermore, in the evaluation test of the friction resistance for the water-repellent coating films obtained in Examples 1 to 25, the water contact angle value after the friction test was slightly lower than that before the friction test. The aqueous coating film also maintained a high water contact angle of 140 ° or more after the friction test. In addition, these water-repellent coating films show the evaluation results of “A” or “B” also in the water drop test and the water drop mobility test, and the water-repellent coating films obtained by the method for producing the water-repellent coating film of the present invention Was confirmed to maintain high water repellency even after friction.

  On the other hand, as is clear from the results of Comparative Examples 1 to 9 shown in Tables 5 to 6, the case of the friction-resistant base film alone (Comparative Example 2) and the case of the super-water-repellent finish film alone (Comparative Example 3) Or when any of the fine particles (A), the fine particles (a), and the mass ratio of each fine particle to each resin composition deviates from the configuration of the present invention (Comparative Examples 4 to 9), It was confirmed that there was no super water repellency even before the friction test, or that the water repellency was significantly lowered after the friction test.

  As described above, according to the present invention, a water-repellent coating film having excellent friction resistance is formed on a substrate surface of various materials and a substrate surface having various surface structures without requiring a special treatment. It is possible to provide a method for producing a water-repellent coating film that can be used, and to provide a water-repellent coating film having excellent friction resistance and a functional material including the same.

  In addition, these water-repellent coating films and functional materials exhibit friction-resistant water repellency that could not be obtained with conventional water-repellent coating films. Functions such as waterproof, snowproof, iceproof, and frostproof can be exhibited. Furthermore, the water-repellent coating film and the functional material of the present invention include various building materials and building materials such as building outer wall materials and building inner wall materials, roofing materials, insulators, conduits, electric cables, electric wire ducts, road signs Can be used for bulletin boards, radome films, aluminum fins, antennas, fences and fences of various materials, tents, waterproof concrete, agricultural films, audio / video equipment, electronic parts and mechanical parts cases (containers), etc. Very useful.

Claims (9)

It contains fine particles (A) having an average particle size of 15 to 500 μm, a resin composition (B), and a solvent (C), and the non-volatile content of the fine particles (A) and the resin composition (B) A first step of applying a first composition having a mass ratio (A: B) of 25:75 to 70:30 on at least one surface of the substrate to form a friction-resistant undercoat film;
It contains fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, a resin composition (b), and a solvent (c). The fine particles (a) and the resin composition ( After applying a second composition having a mass ratio (a: b) of 15:85 to 99: 1 to the non-volatile content of b) on the surface of the friction-resistant base film opposite to the substrate. A second step of drying to form a super water-repellent finish film;
A method for producing a water-repellent coating film, comprising:   The method for producing a water-repellent coating film according to claim 1, wherein the fine particles (a) are fine particles made of a hydrophobic silica compound into which an organosiloxane skeleton is introduced. The total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant undercoat film is 1 to 80 g / m ² ;
The total supported amount (II) per unit area of the fine particles (a) and the nonvolatile content of the resin composition (b) in the super water-repellent finish film is 0.005 to 5 g / m ² ;
The method for producing a water-repellent coating film according to claim 1 or 2.   The total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant base film, and the fine particles (a) and the resin composition in the super water-repellent finish film The mass ratio (I: II) of (b) with the non-volatile content to the total supported amount (II) per unit area is 100: 0.1 to 100: 10. The manufacturing method of the water-repellent coating film as described in any one of them. It contains fine particles (A) having an average particle diameter of 15 to 500 μm and the nonvolatile content of the resin composition (B), and the mass ratio of the fine particles (A) to the nonvolatile content of the resin composition (B) (A : B) a friction-resistant undercoat film having a ratio of 25:75 to 70:30,
Containing fine particles (a) having an average particle diameter of 5 to 500 nm and hydrophobic, formed on the friction-resistant undercoat, and the non-volatile content of the resin composition (b); a super-water-repellent finish film in which the mass ratio (a: b) of a) to the nonvolatile content of the resin composition (b) is 15:85 to 99: 1;
A water-repellent coating film comprising:   6. The water repellent coating film according to claim 5, wherein the fine particles (a) are fine particles made of a hydrophobic silica compound into which an organosiloxane skeleton is introduced. The total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant undercoat film is 1 to 80 g / m ² ;
The total supported amount (II) per unit area of the fine particles (a) and the nonvolatile content of the resin composition (b) in the super water-repellent finish film is 0.005 to 5 g / m ² ;
The water-repellent coating film according to claim 5 or 6.   The total supported amount (I) per unit area of the fine particles (A) and the non-volatile content of the resin composition (B) in the friction-resistant base film, the fine particles (a) and the resin composition ( The mass ratio (I: II) of the non-volatile content of b) to the total supported amount (II) per unit area is 100: 0.1 to 100: 10 among claims 5 to 7 The water-repellent coating film according to any one of the above.   A functional material comprising the water repellent coating film according to any one of claims 5 to 8.