WO1996021523A1 - Process for imparting liquid repellency to metal surface and ultra-liquid-repellent metal material - Google Patents

Abstract

A process for imparting liquid repellency to a metal surface by coating part or the whole of a metal surface having a finely uneven structure and a contact angle of 30° or below against water with a liquid-repelling substance; a liquid-repellent metal material obtained by this process; and the use of the liquid-repellent metal material as a metal material resistant to icing and snowing or a nonslip metal material against ice and snow. The invention also provides a process for imparting liquid repellency to a metal surface by coating a metal surface with a fluoroalkyl phosphate.

Description

 Description Method of imparting liquid repellency to metal surface and super liquid repellent metal material

 The present invention relates to a method for imparting liquid repellency to a metal surface, and in particular, to products requiring liquid repellency, for example, kitchen products such as tables, trays, sinks, bulletin boards such as road signs, and electronic products for mobile phones. The present invention relates to a method for imparting liquid repellency which can be applied to the surface treatment of metal surfaces such as fins for heat exchangers and flowing liquid tubes. The present invention also relates to the application of the metal material imparted with water repellency as described above to a snow-resistant / ice-resistant material and an anti-snow material against ice and snow. Background art

 Conventionally, water repellency has been imparted to a metal surface by a chemical treatment such as coating with a fluororesin-silicone resin or the like. As a more complicated method, a method of forming a composite plating film in which polytetrafluoroethylene oligomer particles are eutectoidally dispersed on a metal surface (Japanese Patent Application Laid-Open No. Hei 218,511,199) is proposed. Have been.

 However, it is difficult to impart a sufficiently satisfactory liquid repellency to the metal surface by the above-mentioned treatment method, or the durability of the liquid repellency is not sufficient, and the work process becomes complicated. Since the fluorine-based compound used for coating is expensive, there is a problem that the product is expensive. For example, when a smooth metal surface is coated with a fluorine resin-silicone resin, only a water repellency of about 100 to 110 degrees as a contact angle with water can be obtained.

 Therefore, an object of the present invention is to provide a method capable of imparting high liquid repellency to a metal surface at low cost and simply. Disclosure of the invention

Under such circumstances, the present inventors have conducted intensive studies, and as a result, have found that It was discovered that liquid repellency was improved by forming a multi-period structure including a long-period uneven structure and a small-period uneven structure in the structure.

(Japanese Patent Application No. 5—3 3 6 4 2 4). Further examinations revealed that if the metal surface, which has a fine uneven structure on the metal surface and has a contact angle to water of 30 degrees or less, is coated with a lyophobic substance, It has been found that excellent liquid repellency can be imparted. In addition, they have found that when a fluoroalkyl phosphate ester compound is used as a coating substance, excellent liquid repellency can be imparted regardless of whether the metal surface has a smooth and fine uneven structure. Furthermore, it was found that ice and snow were extremely unlikely to adhere to the super-water-repellent metal surface obtained in this way, and that ice and snow placed on the metal surface could slide down by slightly tilting the metal surface. . In addition, when the metal having the super water-repellent surface is placed on an ice-snow surface, it has extremely high frictional properties, very little icing or snow accretion on the surface, and when the temperature rises to zero degrees Celsius or higher, ice and snow may be generated. The present inventors have found that water does not cover the surface even when it is melted, does not damage the road surface or floor surface, and is an ideal anti-snow and anti-slip metal material, thus completing the present invention.

 That is, the present invention is characterized in that a liquid-repellent substance is coated on all or a part of a metal surface having a fine uneven structure on the surface and having a contact angle with water of 30 ° or less. The present invention provides a method for imparting liquid repellency to a metal surface.

 Further, the present invention is characterized in that a metal surface having a fine uneven structure on the surface and a contact angle with water of 30 ° or less has a super water-repellent surface coated with a water-repellent substance. The present invention provides a super-water-repellent metal material.

 Furthermore, the present invention is characterized by having a super-water-repellent surface formed by coating a water-repellent substance on a metal surface having a fine concavo-convex structure and having a contact angle to water of 30 degrees or less. It provides a snow-resistant and ice-resistant metal material.

 Furthermore, the present invention is characterized in that it has a super-water-repellent surface formed by coating a water-repellent substance on a metal surface having a fine uneven structure and a contact angle to water of 30 degrees or less. The present invention provides an anti-skid metal material for ice and snow.

Further, the present invention provides a method for imparting liquid repellency to a metal surface, which comprises coating a fluoroalkyl phosphate compound on all or a part of the metal surface. Is what you do.

 Furthermore, the present invention provides a super lyophobic metal material having a super lyophobic surface coated with a fluoroalkyl phosphate compound on the metal surface. BRIEF DESCRIPTION OF THE FIGURES

 (A) and (b) of FIG. 1 are diagrams showing a configuration of a main part of the contact angle measuring device and a contact angle.

 FIG. 2 is a scanning electron micrograph of the acid-treated zinc plate surface in the example of the present invention.

 FIG. 3 is a scanning electron micrograph of a surface of an aluminum plate that has been subjected to a heat treatment in an example of the present invention.

 FIG. 4 is a scanning electron micrograph of the surface of a zinc plate in a cathode subjected to electrolysis treatment in an example of the present invention.

 FIG. 5 is a scanning electron micrograph of the surface of an aluminum plate at the anode subjected to electrolysis treatment in the example of the present invention.

 FIG. 6 is a diagram showing the shape of snow or ice used in the snow resistance test and the ice resistance test. FIG. 7 is an explanatory diagram showing a method for testing snow resistance and ice resistance.

 FIG. 8 is a diagram showing the shape of a metal plate used for measuring slipperiness on ice and snow.

 FIG. 9 is a diagram showing the ice and snow surface preparation container used for the slip property measurement.

 FIG. 10 is a scanning electron micrograph of the surface of a zinc plate in a cathode subjected to electrolysis treatment in Example 8.

 FIG. 11 shows the results of dysman plotting of the contact angles of the zinc plate obtained in Example 8 with various liquids.

 FIG. 12 is a scanning electron micrograph of the surface of the aluminum plate at the anode subjected to the electrolysis treatment in Example 9.

FIG. 13 shows the results of dismantling the contact angles of the aluminum plate obtained in Example 9 with various liquids. BEST MODE FOR CARRYING OUT THE INVENTION

 In the present invention, lyophobic refers to a case where the contact angle of a metal surface with a liquid is larger than 90 degrees, and such a surface is called a lyophobic surface. The object of the present invention is not necessarily limited to a surface to which water adheres, but is also applied to increase a contact angle with a liquid containing alcohol, oil, and surfactant. At this time, the liquid-repellent substance used in the final coating treatment of the metal surface is a substance having a contact angle of more than 90 degrees with respect to the liquid.

When forming a lyophobic metal surface, the contact angle to water is 30 degrees or less.As the fine uneven structure of the hydrophilic metal surface, the actual surface area per cm ² of the uneven structure in plan view is sufficiently large. Is generally preferred. However, even if the actual surface area of the uneven surface is increased by increasing the height of the unevenness to the size of a normal droplet (about 2 mm) or more, the liquid repellency is not improved. The liquid repellency is affected by the density of the actual surface near the very surface of the uneven structure that can come in contact with the droplets, that is, the actual surface area per unit volume. It is preferred.

In this respect, the height of the fine uneven structure on the surface is preferably 800 m or less, more preferably 300 m or less, and particularly preferably 30 um or less. Under these conditions, it is preferable that the actual surface area per cm ² of the concavo-convex structure in plan view is large, specifically, 3 cm ² or more. However, if the actual surface area is too large, the uneven structure becomes flaky or thin-line, and the mechanical strength of the metal surface is undesirably reduced. Therefore, from the viewpoint of maintaining the strength of the metal surface, the actual surface area of the uneven structure is preferably less than 2 Ocm ² . In order to effectively use the entire actual surface area of the concavo-convex structure, the contact ratio of the irregular surface, i.e. the contact area of the concavo-convex structure when addressed a smooth rigid on its uneven surface, rigid surface 1 cm ² per 0.2 cm ² or less.

In the present invention, the actual surface area refers to the surface area measured by the BET method. This BET method uses the BET adsorption formula proposed by S. B runauer, PH Emmett and E. Telel, based on the adsorption of gas molecules (nitrogen gas, krypton gas) on a solid surface. How to calculate the surface area of a solid It is. The height, width and contact area of the uneven structure were measured by image analysis from a cross-sectional SEM photograph of the solid.

 From the above, the range of the width and height of the fine uneven structure formed on the metal surface is 1 to 800 m, more preferably 1 nm to 300 m, especially 50 to 30 m. Preferably, the structure need not be uniform. Further, the shape of the concavo-convex structure is not particularly limited, and may be any of scaly, prismatic, cylindrical, pyramidal, conical, and needle-like. Furthermore, a fractal structure or a self-fine structure having a fractal dimension of two or more and less than three dimensions, which is formed by complicatedly combining those shapes, may be used. There is no particular limitation on the method for producing such a hydrophilic metal surface, and it may be an artificially processed one or a naturally existing one. In particular, methods of artificially processing include (1) a method of polishing or cutting the metal surface, (2) a method of immersing the metal surface in an acid or alkaline solution, and (3) a method of polishing the metal. (4) a method using metal as an electrode and utilizing electrolysis, and (5) a method based on metal structure.

 Specific examples of the above (1) include a method of sanding with sandpaper or metal file, a method of sand blasting, or a method of cutting a V-groove or a cross hatch on a metal surface with a cutter.

 The method (2) can be implemented, for example, by the following steps. Mix an acid such as hydrochloric acid and water, adjust the concentration to an appropriate pH between pH 1 and 6, immerse the target metal plate in this solution, and hold it at a specified temperature for a specified time As a result, a fine uneven structure is formed on the metal surface. When an alkali is used, sodium hydroxide or the like is mixed with water, the concentration is adjusted to an appropriate pH between pH 8 and 14, and the target metal plate is immersed in this solution. By holding at a predetermined temperature for a predetermined time, a fine uneven structure is formed on the metal surface.

 As a method of the above (3), there is a method of holding a target metal plate at a predetermined temperature for a predetermined time in an atmosphere containing water vapor to cause natural corrosion.

As the method (4), there is a method in which a target metal plate is immersed in an electrolyte solution as an anode or a cathode, and a predetermined voltage is applied between both electrodes at a predetermined temperature for a predetermined time. At this time, a method of forming a concavo-convex structure by eluting metal from the target metal plate And a method of forming a concavo-convex structure by depositing a metal or other substance in an electrolyte solution on a target metal plate. Examples of the former include electrolytic polishing, and the latter include electroplating and electrodeposition coating.

The above method (5) can be carried out, for example, by the following steps: a liquid having a target metal heated to above its melting point and melted in a mold having fine irregularities on the _c surface. By pouring it into metal, and then cooling and solidifying it, it is possible to obtain a metal surface with the 铸 -shaped fine uneven structure transferred to the surface.

 The metal used in the present invention is not particularly limited as long as a fine uneven structure is formed by the above-mentioned processes (1) to (5). However, the metal used in the above-mentioned processes (2) to (4) is not particularly limited. Suitable metals include zinc, nickel, iron, aluminum or their alloys, stainless steel and the like.

As described above, the metal surface having a fine uneven structure on the surface, if there sufficient relief structure is formed, the _c present invention as a contact angle of 3 0 degrees or less and comprising a hydrophilic metal surface to water A liquid-repellent surface can be obtained by coating such a hydrophilic metal surface with a liquid-repellent substance. The thickness of the coating layer at this time is not particularly limited as long as it does not eliminate fine irregularities on the surface, and is preferably 100 nm or less. In addition, prior to or simultaneously with the treatment with these liquid repellent substances, a heat-proof treatment such as chromate treatment can be performed.

As a method of coating a hydrophilic metal surface with a lyophobic substance, there is typically a method of treating the metal surface with various coupling agents. The liquid-repellent substance used in the present invention may be any substance that has a hydrophobic group or the like by reacting with a functional group (for example, a hydroxyl group) on a metal surface, and is not limited. Examples of the _c- silane coupling agent include a coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, an isocyanate-based coupling agent, and a zirconium-based coupling agent. Examples include trichloroalkylsilanes of the formula (1), trimethoxyalkylsilanes of the formula (2), and triethoxyquinalkylsilanes of the formula (3). C -Si-C _n H ₂ n ₊ l (1)

0CH ₃

CH ₃ 0-Si-CnH ₂ n + i (2)

 0CH3

OC2H5

C ₂ H ₅ 0-S G C _n H _{2n + 1} (3)

 OC2H5

(In the formula, n is an integer of 6 to 20.) In the compounds of the above formulas (1) to (3), a reaction part reacting with a functional group on the metal surface (C 1 group, 〇CH ₃ group, respectively) , OC ₂ H ₅ groups) and one water-phobic part (long-chain alkyl group) for imparting water repellency. For example, there may be two to three hydrophobic parts. The structure of the hydrophobic part may be different. Further, some or all of the hydrogen atoms in the hydrophobic portion may be replaced by fluorine atoms, as in the alkyltrichlorosilane fluoride represented by the following formula (4).

 Z £

C £ -Si-C ₂ H ₄ -C ₆ F ₁₃ (4)

 Cf

The titanate-based coupling agents are not limited to the following examples, and typical ones are isopropylpropylisostearoyl titanate, isopropyltrioctynol titanate, and isopropyl alcohol represented by the following formula (5). Lidodecylbenzenesulfonyl titanate, isopropylbenzene tris (dioctyl pyrosulfate) titanate, tetraoctylbis (ditridecylphosphite) titanate, tetra (2,2-diaryloxymethyl-1-butyl) bis ( Ditrilideyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate And isopropyl tri (dioctyl phosphate: L-t) titanate, diisostearoylethylene titanate and the like. Further, some or all of the hydrogen atoms of the hydrophobes in these coupling agents may be replaced by fluorine atoms.

CH3--C 17 H35) (5)

Representative examples of the aluminum-based coupling agent include an acetoalkoxyaluminum diisopropylate represented by the following formula (6).

The treatment using the silane coupling agent is performed, for example, as follows. A mixture of hexadecane and a mixture of formaldehyde and carbon tetrachloride is dried over molecular solvent, and an appropriate amount of a silane coupling agent is added to the dried solvent to obtain a treatment solution. The treatment is carried out by immersing a metal having a concavo-convex structure in a dry atmosphere at an appropriate temperature for a predetermined time. After immersion, wash with black mouth form and water and dry.

 The treatment using a titanate-based coupling agent or an aluminum-based force-binding agent is performed, for example, as follows. Toluene is dried with a molecular sieve or the like, and an appropriate amount of a titanate-based coupling agent or an aluminum-based coupling agent is added to the dried toluene to obtain a treatment solution. The treatment is carried out by immersing a metal having an uneven structure at a suitable temperature for a predetermined time in a dry atmosphere. After immersion, wash with an appropriate organic solvent or an aqueous solution containing an activator for washing, wash with water and dry under appropriate conditions.

By the way, a fluoroalkyl phosphate compound is used as a coating agent. In this case, excellent liquid repellency can be obtained even when the metal surface is smooth or has a fine uneven structure as described above. However, it is particularly preferable to coat the metal surface having the fine uneven structure as described above.

 Surprisingly, when fluoroalkyl phosphate ester is used as a coating agent, the effect of improving the liquid repellency by roughening the surface is far from what is expected from ordinary wetting theory. It exceeds. According to wetting theory, the effect of surface roughening on the wettability of a solid surface depends on the contact angle of the droplet on a flat solid surface.

When the contact angle is larger than 90 degrees, the contact angle is further increased, and when the contact angle of the droplet on the flat solid surface is less than 90 degrees, the contact angle is further decreased.

(See A. W. Adamson, Physical Chemistry of Surfaces, John Wiley & Sons, New York). However, when coated with a fluoroalkyl phosphate ester, droplets that show a contact angle of less than 90 degrees on a smooth metal surface on the surface treated with the treatment solution, or rough surfaces, When the oxidized metal surface is placed on the surface treated with the treatment liquid, a contact angle of 90 ° or more is exhibited.

As the fluoroalkyl phosphoric acid ester used in the present invention, a mono (fluoroalkyl) phosphate, a di (fluoroalkyl) phosphate or a salt thereof is preferable, and a mono (C ₆ -C ₃₆ fluoroalkyl) is particularly preferable. ) Phosphate esters, di (C ₆ -C ₃₆ fluoroalkyl) phosphate esters or salts thereof are preferred. More specifically, a monofluoroalkyl phosphate represented by the following general formula (7)

R _f 0- P (= 0) (-0-X) ₂ (7)

Or a difluoroalkyl phosphate represented by the general formula (8)

(R _f O) ₂ -P (= 0) (-0-X) (8)

(In the formula, R _f represents a linear or branched fluoroalkyl group, and X represents any one of a hydrogen atom, an alkali metal, an alkaline earth metal, ammonia, and an alkylammonium having 1 to 4 carbon atoms.) Can be These monoesters and diesters may be used as a mixture.

The linear or branched fluoroalkyl group represented by R _f has 6 to 36 carbon atoms from the viewpoint of ease of synthesis, and further has 8 to 36 carbon atoms from the viewpoint of liquid repellency. preferable. R, may be a perfluoroalkyl group composed of only carbon atoms and fluorine atoms, or a fluoroalkyl group in which a part of hydrogen is replaced by fluorine. However, also in the latter case, in order to improve the liquid repellency, it is preferable that the proportion of fluorine is large, and it is particularly preferable that the terminal group is a CF ₃ — group.

Examples of the alkali metal represented by X include sodium, potassium, rubidium, cesium, and the like. Examples of the alkaline earth metal include calcium, potassium, stomium, and the like. Examples of the alkylammonium (4) include monomethylamine, dimethylamine, trimethylamine, monoethylamine, dimethylamine, triethylamine, monopropylamine, dipropylamine, tripropylamine and the like and proton. Alkyl ammonium formed. From the viewpoints of stability and easiness of treatment, X is most preferably a hydrogen atom. As a coating method using a _c -fluoroalkyl phosphate compound, for example, (1) a fluoroalkyl phosphate compound (2) a method of applying the treatment liquid directly to the metal surface, (3) a method of immersing a piece of metal in the treatment liquid and applying a voltage between them. A method of applying the voltage to perform electrolysis is exemplified.

 The solvent used in this treatment liquid is not particularly limited as long as it is a solvent that can dissolve the fluoroalkyl phosphatase, and examples thereof include alcohol, ether, and fluorocarbon. In this treatment solution, the fluoroalkyl phosphoric acid ester is usually incorporated in an amount of 0.01 to 50% by weight, preferably 0.1 to 10% by weight.

 The method (1) can be carried out, for example, by adsorbing the fluoroalkyl phosphate on the metal surface by holding the metal plate in the above-mentioned treatment solution at a predetermined temperature for a predetermined time. .

In the above method (2), for example, the above treatment liquid is directly applied to a metal surface with a brush, a brush, or the like, or is sprayed or sprayed on a metal surface, and then the metal is exposed to air. The method (3), which can be carried out by allowing the solvent to evaporate after standing for a predetermined period of time, can be performed, for example, by treating the above-mentioned processing solution with the metal to be provided with liquid repellency as the positive electrode and the other metal as the negative electrode. Immersed, prescribed voltage between both electrodes at prescribed temperature at prescribed temperature The application can be carried out by adsorbing fluoroalkyl phosphate ester on the metal surface on the anode side by applying for a time.

 The metal material obtained as described above has excellent liquid repellency (especially water repellency), and is useful as a material requiring various liquid repellencies.

 By the way, conventionally, in order to prevent snow and ice from adhering to the solid surface, a method has been adopted in which the solid surface is made as smooth as possible to reduce friction with snow and ice. It has also been pointed out that snow-resistance can be imparted by covering the solid surface with a water-repellent paint containing fluorine compound particles as a component (Japanese Unexamined Patent Application Publication No. Hei 6-12828-1994). No. 2 841). However, on the metal surface, smoothing it alone does not provide sufficient snow and ice resistance because of the high affinity between the metal surface and water. On the other hand, the method of treating the surface with a paint containing fluorine compound particles as components is not widely used because the surface strength is not sufficient and the fluorine compound is expensive.

 On the other hand, the metal material of the present invention has sufficient mechanical strength, is inexpensive, and has excellent resistance to snow and ice, and is suitable for shelves, luggage, antennas, and capes in a freezing warehouse. It can be widely used as a material for saws, steel towers, jigs for civil engineering machinery, houses and roofs.

 In addition, the frictional force is significantly reduced on frozen ground in cold regions, snowy surfaces in snowy countries, and frozen floors in refrigeration warehouses. It is dangerous because people fall down when walking. In order to prevent such dangers, it has been a conventional method to create an uneven structure on a solid surface in order to increase the frictional force between the contacting surfaces. In extreme cases, spikes and needle-like projections are formed on the soles of the shoes to prevent slippage on ice and snow.

However, surfaces with sharp protrusions, such as spikes, can severely damage the road or floor when placed on ice or snow-free roads or floors. Also, there is a risk of injury by accidentally touching the projection. On the other hand, if a fine uneven structure is formed on the metal surface to increase friction, ice and snow will easily adhere to the metal surface, and the friction surface will be covered with ice and snow, and the frictional force may decrease. Moreover, below zero degrees Celsius In the above environment, water that has melted from ice and snow covers the metal surface and acts as a lubricant, impeding the improvement of frictional force.

 On the other hand, the anti-skid anti-slip metal material of the present invention, despite having no sharp projections, produces high friction on the ice and snow surface, so that shelves, luggage, shoes, and vehicles in a freezing warehouse can be used. It can be used as an anti-slip material for surfaces that come in contact with metal such as ice or snow such as a ring. Further, icing and snow accretion on the surface of the metal material of the present invention are extremely small, and even if the temperature becomes zero degrees Celsius or higher and the ice and snow melts, water does not cover the surface, and the road surface and floor surface are damaged. Absent.

 Furthermore, if the liquid-repellent metal surface obtained according to the present invention is used for the air-side heat transfer surface of a heat exchanger such as an air conditioner or a refrigerator, a frost formation phenomenon can be suppressed for a long time. As a result, the reduction in heat exchange efficiency due to frost formation can be reduced.

 Further, if the liquid-repellent metal surface obtained by the present invention is used as a contact surface with a liquid of a pipe (flowing pipe) through which liquid flows, such as a water pipe or a funnel, the flow of the liquid is reduced. A flow tube that is fast and free of liquid after use can be obtained. Example

 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 and Comparative Example 1

An uneven surface (height 5 m, width: 0.30 cm x 10 cm, thickness 0.3 mm) made by polishing a zinc sheet (made by Niraco) with a # 200 sandpaper 1-5 0 〃M, actual surface area per 1 cm ² in a plan view 3. 3 cm ^2, the contact area ^{0. 0 0 2 6 cm 2} ) is formed, 1 H, 1 H, 2 H, 2 H- Coupling treatment was performed using perfluorooctyl trichloro σ silane (manufactured by PCR) to make the surface water-repellent. Coupling is performed by mixing 300 g of hexadecane (manufactured by Tokyo Chemical Industry), 30 g of carbon tetrachloride (manufactured by Kanto Chemical Co., Ltd.), and 30 g of Kuroguchi Holm (manufactured by Kanto Chemical Co., Ltd.). Add about 1 g of 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane to the solvent dehydrated with molecular sieve 3A, and immerse the zinc plate in a dry nitrogen atmosphere at room temperature for 12 hours. By I went. After the coupling treatment, the membrane was washed twice with a black-mouthed form 300, air-dried, further washed with water, and air-dried.

 The contact angle of the metal surface to distilled water was measured using an optical contact angle meter (CA-A, manufactured by Kyowa Interface Science Co., Ltd.). That is, as shown in FIGS. 1 (a) and 1 (b), test sample 1 was placed on sample stage 2 of the above-mentioned optical contact angle meter, and distilled water was poured into syringe 3 for dropping droplets. A droplet 4 having a diameter of l mm was formed at the tip of the needle of the nozzle 3. The gap between the liquid drop 4 and the test sample 1 was maintained at about 1 cm, and the syringe 3 was vibrated to drop the drop 4 at the needle tip onto the test sample 1. After dropping the droplet 4, the contact angle (0) between the droplet 4 and the test sample 1 was measured.

 The contact angle of water on a flat zinc plate was 79 degrees, but by polishing the zinc plate with a paper file, the contact angle to water was reduced to 29 degrees, resulting in a hydrophilic surface. By subjecting the hydrophilic surface to silane coupling treatment, a water-repellent surface having a contact angle to water of 141 degrees was obtained.

As a comparative example, when the surface of a flat zinc plate having a contact angle of water of 79 degrees was subjected to the same silane coupling treatment, the contact angle with water was only 105 degrees, and sufficient water repellency was not obtained. The height of the irregularities on the surface of the zinc plate is 1 μm or less, the width is 300 μm or more, the actual surface area per 1 cm ^{2 in} plan view is 1.0 to 1.2 cm ² , and the contact area Was 0.6 cm ² or more.

Example 2

A zinc plate (manufactured by Niraco) having a size of 30 cm x i 0 cm and a thickness of 0.3 was immersed in an aqueous solution adjusted to pH 3 with hydrochloric acid at room temperature for 3 days. When the surface was observed using an electron microscope (Hitachi, FE-SEM, S-400), a fine concave-convex structure was formed as shown in FIG. Height 2-5 0 〃 m of this concavo-convex structure, the width 0. 5 to 2 5 // m, the actual surface area per 1 cm ² in plan view 1 6. 2 cm ^2, the contact area is 0. It was 0.43 cm ² .

The surface was made liquid-repellent by a cutting treatment using octyl decyltrichlorosilane (manufactured by Tokyo Chemical Industry Co., Ltd.). The coupling treatment was performed by mixing 300 g of hexadecane (Tokyo Kasei Co., Ltd.), 30 g of carbon tetrachloride (Kanto Chemical Co., Ltd., special grade), and 30 g of Kuroguchi Holm (Kanto Chemical Co., Ltd., special grade). After dehydrating the solvent with molecular sieve 3 A, Approximately 1 g of decyltrichlorosilane was added, and the zinc plate was immersed in the treatment solution for 12 hours in a dry nitrogen atmosphere at room temperature. After the treatment, the membrane was washed twice with a black form 300 and air-dried at room temperature. After drying, the sample was washed with water and air dried again at room temperature.

 The contact angle of the zinc plate sample thus obtained with water and glycerin was measured using an optical contact angle measuring device (CA-A type, manufactured by Kyowa Interface Science Co., Ltd.). The contact angle of water on a flat zinc plate was 79 degrees, but by immersing it in acid, the contact angle with water was reduced to 16 degrees, resulting in a hydrophilic surface. By subjecting the hydrophilic surface to silane coupling treatment, a liquid-repellent surface having a contact angle of 160 degrees with water and a contact angle of 155 degrees with glycerin was obtained.

Example 3 and Comparative Example 2

An aluminum plate (manufactured by Niraco Co., Ltd.) with a size of 3 O cm and 1 O cm and a thickness of 0.3 mm was placed in a solution prepared by adding 30 g of sodium hydroxide to 700 ml of tap water to form an aqueous solution. Soaked at room temperature for 3 hours. When the surface structure was observed using an electron microscope (Hitachi, FE-SEM, S-40000), a fine uneven structure was formed as shown in FIG. The height of this uneven structure was 2 m, the width was 1 to 20 m, the actual surface area per 1 cm ^{2 in} plan view was 4.3 cm ² , and the contact area was 0.0015 cm ² .

The surface was made water-repellent by a coupling treatment using isopropyltriisostearoyl titanate (variety: KR-TTS, manufactured by Ajinomoto Co.). Coupling is performed using toluene (special grade, manufactured by Wako) dehydrated using molecular sieve 3A (manufactured by Wako).

5 g were mixed, and an aluminum plate was immersed in the treatment liquid at a temperature of 100 ° C. for 5 hours. After the coupling treatment, the membrane was washed twice with toluene ^, dried at room temperature, further washed with water, and air-dried at room temperature.

The contact angle of the aluminum sample thus obtained with water was measured using an optical contact angle measuring device (CA-A type, manufactured by Kyowa Interface Science Co., Ltd.). The contact angle of water on a flat aluminum plate was 70 degrees, but by immersing it in an alkaline solution, the contact angle with water was reduced to less than 3 degrees, and the hydrophilicity was reduced. Surface. By treating the hydrophilic surface with a titanate-based coupling agent, A water-repellent surface having a contact angle of 158 degrees was obtained.

As a comparative example, when a similar coupling treatment was performed on a flat aluminum plate surface having a water contact angle of 70 degrees, the contact angle with water was only 110 degrees, and sufficient water repellency was not obtained. Was. Also, the height of the unevenness of the surface of the aluminum plate 1 u rn or less, the width 3 0 0 m or more, 1 real surface area per 1 cm ² in plan view. 1 cm ^2, the contact area is 0. 5 cm ² That was all.

Example 4 and Comparative Example 3

An iron plate (manufactured by Niraco Co., Ltd.) with a size of 30 cm, 10 cm and a thickness of 0.3 cm is immersed in a 3% by weight saline solution, taken out, and left in the air for 2 weeks to corrode the surface. And fine uneven structure (height 2 to 20〃1, width 0.5 to 30 / m, actual surface area per 1 cm ^{2 in} plan view 13.7 cm ² , contact area 0.0 0.5 cm ² ) was formed and subjected to a coupling treatment using octadecyl trichlorosilane (manufactured by Tokyo Chemical Industry Co., Ltd.) to make the surface water-repellent. The coupling treatment is performed by mixing 300 g of hexadecane (manufactured by Tokyo Chemical Industry), 30 g of carbon tetrachloride (manufactured by Kanto Chemical Co., special grade), and 30 g of Kuroguchi Form (manufactured by Kanto Chemical Co., Ltd.). Approximately 1 g of octyl decyl trichlorosilane was added to the solvent dehydrated with molecular sieve 3A, and the steel plate was immersed in a dry nitrogen atmosphere at room temperature for 12 hours. After the coupling treatment, the membrane was washed twice with a black-mouthed form 300 and air-dried.

 The contact angle of the iron plate sample thus obtained with water was measured using an optical contact angle measuring device (CA-A type, manufactured by Kyowa Interface Science Co., Ltd.). Although the contact angle of water on a flat iron plate was 83 degrees, the natural corrosion of the water reduced the contact angle to water to less than 3 degrees, resulting in a hydrophilic surface. By treating the hydrophilic surface with a silane-based coupling agent, a water-repellent surface having a contact angle to water of 160 degrees was obtained.

As a comparative example, when a similar cutting treatment was performed on a flat iron plate surface with a water contact angle of 83 degrees, the water contact angle was only 103 degrees, and sufficient water repellency was not obtained. . The height of the irregularities on the iron plate surface is 1 m or less, the width is 300 m or more, the actual surface area per 1 cm ^{2 in} plan view is 1.0 to 1.2 cm ² , and the contact area is 0. 5 cm ² or more. Example 5

Size 30 cm 10 cm. Two 1 mm thick zinc plates (manufactured by Niraco) are opposed to each other as electrodes in a 0.01 mo £ / \-zinc chloride aqueous solution at an interval of 42 mm. A constant voltage of 1.0 V was applied between both electrodes for 5 hours using a stabilized DC power supply (GPS-300, manufactured by Instex). As a result, zinc ions in the aqueous zinc chloride solution were deposited on the surface of the zinc plate of the cathode. When the fine structure of the cathode surface was observed with an electron microscope (FE-SEM, S-400, manufactured by Hitachi, Ltd.), a fine uneven structure was formed as shown in FIG. Height 1-2 0〃M of this concavo-convex structure, width 0. 2 to 3 0 um, the actual surface area per 1 cm ² in plan view 1 5. 3 cm ^2, the contact area of 0. 0 1 1 cm ^{Was 2} .

 The liquid repellency was achieved by a coupling treatment using octadecyl trichlorolanne (manufactured by Tokyo Chemical Industry Co., Ltd.). The coupling treatment is performed by mixing 300 g of hexadecane (manufactured by Tokyo Kasei Co., Ltd.), 30 g of carbon tetrachloride (manufactured by Kanto Chemical Co., Ltd., special grade), and 30 g of Kuroguchi Form (manufactured by Kanto Chemical Co., Ltd., special grade). About 1 g of octadecyltrichlorosilane was added to the solvent dehydrated with molecular sieve 3A, and the zinc plate used as a cathode was immersed in a dry nitrogen atmosphere at room temperature for 12 hours. After the coupling treatment, the plate was washed twice with 300 parts of chloroform and air-dried.

 The contact angle of the zinc plate sample thus obtained with water and glycerin (Kanto Chemical Co., Ltd., special grade) wetting index standard solutions No. 54 and No. 48 (Wako Co., Ltd.) was determined by the optical contact angle. The measurement was performed using a measuring device (manufactured by Kyowa Interface Science Co., Ltd., CA-A type).

 The contact angle of water on a flat zinc plate was 79 degrees, but by electrolyzing it, the contact angle with water was reduced to less than 3 degrees, resulting in a hydrophilic surface. By treating the hydrophilic surface with a silane coupling agent, a lyophobic surface having contact angles with various liquids shown in Table 1 was obtained. Table 1 Water Glycerin Wetting Index Standard Solution Wetting Index Standard Solution

 Να5 4 Να4 8

Contact angle (degree) 163 155 151 140 Example 6

In Example 5, two pieces of Lumidium (manufactured by Niraco Co., Ltd.) of size 3 Ocm x 10 cm and thickness 1 were used instead of the zinc plate, and 25 N-sulfuric acid 5 was used instead of the aqueous zinc chloride solution. Except for using a mixture of 1 liter of ion-exchanged water, installation was performed in the same manner as in Example 5, and an electrode current density of 1 OmAZcm was obtained using a stabilized DC power supply (manufactured by Instek, Inc., GPS-3300). ² for 3 hours. As a result, aluminum was eluted from the aluminum plate surface of the anode, and a fine uneven structure was formed on the surface. When the fine structure of the anode surface was observed using an electron microscope (FE-SEM, S-400, manufactured by Hitachi, Ltd.), a fine uneven structure was formed as shown in FIG. The height of this uneven structure is 2〃111, the width is 1 to 1.5 / m, the actual surface area per 1 cm ^{2 in} plan view is 14.7 cm ² , and the contact area is 0.0072 cm ^Two .

The liquid repellency was achieved by a force ring treatment using 1 H, 1 H, 2 H, 2 H-perfluorooctyl trichlorosilane (manufactured by PCR). Coupling treatment is as follows: Hexadecane (Tokyo Kasei) 300 g, carbon tetrachloride (Kanto Chemical Co., special grade) 30 g, Kuroguchi Holm (Kanto Chemical Co., special grade) 30 g About 1 g of 1 H, 1 H, 2 H, 2 H-perfluorooctyl trichlorolane was added to the solvent mixed and dehydrated with 1 A sieve 3 A, and the aluminum plate used as the anode was dried at room temperature. This was performed by immersing in a nitrogen atmosphere for 12 hours. After the coupling treatment, the membrane was washed twice with black mouth form 300, dried, washed again with water, and air-dried at room temperature. The contact angle of the aluminum plate sample thus obtained with water, glycerin (Kanto Chemical Co., Ltd., special grade) and wetting index standard solutions No. 54 and No. 48 (Wako Co., Ltd.) was determined by the optical contact angle. The measurement was performed using a measuring device (manufactured by Kyowa Interface Science Co., Ltd., CA-A type). The contact angle of water on a flat aluminum plate was 70 degrees, but by electrolyzing it, the contact angle with water was reduced to less than 3 degrees, resulting in a hydrophilic surface. . By treating the hydrophilic surface with a silane coupling agent, a lyophobic surface having contact angles with various liquids shown in Table 2 was obtained. Table 2

Test example 1

 Using the super-water-repellent zinc liquid obtained as in Example 1, its ice and snow accretion were evaluated as follows.

 The ice used for the evaluation of ice resistance was a block-shaped ice with a side of 2 cm (ice machine; manufactured by HOSH I ZAK I, manufactured by IM-200 DWJ). As shown in Fig. 6, a slice of ice, crushed to a maximum length of 1 cm, was used. For evaluation of snow resistance, we used natural snow (Fukushima Prefecture, Taikura Ski Resort) that was hardened as shown in Fig. 6.

The super-hydrophobic zinc plate obtained as described above is placed horizontally on the ground as shown in Fig.7. Then, snow or ice 1 is placed on sample plate 2 and sample plate 2 is gradually tilted. Then, the angles 0 _SI and _{P at} which the snow or ice 1 started to slide were recorded.

Under the condition of a temperature of 1-5 ° C, the block ice started to slide at 0 _{sll P at} 25 degrees. 0 _sl , _{P slipped at} 25 degrees on the slag ice, and 0 _SI , _P for snow (temperature 2 ° C) was 20 degrees. As a comparative example, when a similar experiment was performed using an untreated flat zinc plate, 0 _{sli P} for _block ice and flounder ice was ₅₀ degrees or more, and 0 _sl and ρ for snow were 90 degrees. became. The width of the unevenness of the zinc plate surface 3 0 0 m or more, 1 m hereinafter height, 1 real surface area per cm ² 1. 0 to 2 cm ^2, the contact area per rigid 1 cm ² 0 6 cm ² or more.

Test example 2

The water-repellent zinc plate obtained as in Example 2 is horizontally placed on the ground as shown in FIG. After that, snow or ice 1 is placed on the sample plate 2, and the sample plate 2 is gradually tilted. Then, the angle at which snow or ice 1 starts to slide 0 _{S 11} . Was recorded. Under the temperature of 5 C, the block ice started to slide at 24 degrees in S _S ,, _P. 0 _SI , _P slipped at 24 degrees on the salmon ice, and S _{sll P} against snow (temperature of 2 ° C) was 20 degrees. I went there, block ice And 0 _{sli P} for snow ice is ₅₀ degrees or more, and 0 _{sli P} for snow is 90 degrees.

Test example 3

The water-repellent aluminum plate obtained as in Example 3 is horizontally placed on the ground as shown in FIG. After that, snow or ice 1 is placed on the sample plate 2, and the sample plate 2 is gradually tilted. Then, the angles 0 _SI and _{P at} which the snow or ice 1 started to slide were recorded. Under the condition of a temperature of 1-5 ° C, the block ice started to slide at 24 degrees in S _{S 1} and _P. 0 _{sli P slipped at 24} degrees on the _Zarame ice, and 0 _{sli P} for snow (temperature 2 ° C) was 20 to ₂₂ degrees. As a comparative example, a similar experiment was performed on an untreated flat aluminum plate. As a result, 0 _{sli P} for block ice and flounder ice was ₅₀ degrees or more, and 0 _{sli P} for snow was 90 degrees.

Test example 4

The water-repellent iron plate obtained as in Example 4 is horizontally placed on the ground as shown in FIG. Then, snow or ice 1 is placed on sample plate 2 and sample plate 2 is gradually tilted. Then, the angle at which snow or ice 1 starts to slide is 0 _sll . Was recorded. At a temperature of 15 ° C, the block ice began to slide at 0 _{sli P at 16-17} ° C. 0 _sl , _{P slipped at} 16 to 17 degrees on the salam ice, and 0 _SI , _P for snow (temperature 2 ° C) was 16 to 20 degrees. As a comparative example, a similar experiment was performed on an untreated flat iron plate, and the value of 0 _{sli P} for block ice and flounder ice was 60 degrees or more, and that for snow was 90 degrees.

Test example 5

The water-repellent zinc plate obtained as in Example 5 is placed horizontally on the ground as shown in FIG. After that, snow or ice 1 is set on the sample plate 2, and the sample plate 2 is gradually tilted. Then, the angles S _SI , _{P at} which the snow or ice 1 started to slide were recorded. At a temperature of 5 ° C, the block ice began to slide at _{25 s} with 0 _{sli P.} Coarse ice even Suberidashi at 0 _{sli P} 2 5 degrees, as _c Comparative Example 0 _{sli P} against the snow (air temperature 2 ° C) was 2 0 degrees, subjected to the same experiments a flat zinc plate of untreated and where, 0 _{sli P} for block ice and coarse ice is 5 0 degrees or more, 0 _{sll P} against snow 9 0 degrees and summer Ryoko. Test example 6

The water-repellent aluminum plate obtained as in Example 6 is horizontally placed on the ground as shown in FIG. After that, snow or ice 1 is placed on the sample plate 2, and the sample plate 2 is gradually tilted. Then, angles 0 _{S 1} and _{P at} which the snow or ice 1 starts to slide are recorded. Under the condition of a temperature of 1-5 ° C, the block ice started sliding at 0 _{sli P at 23} degrees. At Zara main ice Suberidashi at 0 _{sli P} 2 three times, 0 _{sll P} against the snow (air temperature 2 ° C) was 1. 6 degrees. As a comparative example, the microstructure before the silane coupling treatment was applied, and a similar experiment was performed on the _{hydrophilic surface.At} a temperature of 15 ° C, S _{sli P} for block ice was ₅₀ ° C. On the other hand, 0 _{sli P} for the _salmon ice was 90 degrees, which means that the snow- and ice-resistance requires a fine structure on the surface and a chemical water-repellent treatment on the surface.

Test example 7

 The water-repellent aluminum plate created in Example 6 was installed at an angle of 60 degrees with respect to the ground (Kao Corporation, at the site of Sakata Plant, at a temperature of 1), and the snow accumulation on the surface was checked. investigated. As a result, it was found that snow slipped off the surface of the water-repellent aluminum very quickly, and did not go off. As a comparative example, a similar experiment was performed on an aluminum plate obtained by performing coupling 'treatment on flat aluminum, and it was found that snow adhered to one surface.

Test example 8

The super-water-repellent zinc plate obtained as in Example 1 was bent at a length of 25 cm as shown in FIG. 8, and further placed in a container shown in FIG. 9 with block ice (2 cm square) and coarse ice (length lcm) or put snow and put a super water-repellent zinc plate on it. Then, gradually tilt the container containing block ice (2 cm square), coarse ice (about lcm in length), or snow, and the angle at which the super water-repellent zinc plate starts to slide 0 _{S 1} , _P On the ice (5 ° C), 0 _{sli P} started to slide at 20 to 30 degrees. On coarse ice (temperature 5 ° C), 0 _{sll P} slipped at 33 degrees, and on snow (temperature 2 degrees), it slipped even at the measurement limit of 80 degrees.

As a comparative example, was a similar experiment with a flat zinc plate, the ice 0 _{S |, P} is

At 10 degrees, on coarse ice S _{sl 1 P} is 7 degrees, and on snow e _s ,,. Is 10 ~! Twice I got it. Moreover, when the same test was conducted with respect to the reduced zinc plate to the contact angle or 2 9 degrees with respect to water by sanding Comparative Example, 6> _s, the value of i _P is stopping effect slip large However, there was a practical problem due to ice and snow adhering to the surface. The width of the unevenness of this zinc plate surface 1 to 5 0 m, height actual surface area per 5 zm, 1 cm ² is 3. 3 cm ^2, the contact area per rigid l cm ² is 0.0 0 It was ² 6 cm 2.

Test example 9

The super-water-repellent zinc plate obtained as in Example 2 was processed as shown in FIG. 8, and further placed in a container shown in FIG. 9 in the form of block ice (2 cm square), coarse ice (about 1 cm in length), or Put snow in it and place a super water-repellent zinc plate on it. Then, gradually tilt the container containing block ice (2 cm square), coarse ice (about l cm in length), or snow, and the angle at which the super-water-repellent zinc plate starts to slide 0 _sl , Ρ As a result, on ice (temperature 5 ° C), _{øsli P} started to slide at 20 to 30 degrees. On coarse ice (temperature 5 ° C), 0 _{sli P} started to slip at about 30 ° C, and on snow (temperature 2 ° C), it did not slip even at the measurement limit of 80 ° C.

As a comparative example, a similar experiment was performed on a flat zinc plate. 0 _{S 11 P} on ice was about 10 degrees, 0 _{sli P} on coarse ice was 7 degrees, and 0 _{slip on} snow was 10 to 1 degree. It was twice. As a comparative example, a similar test was performed on a zinc sheet whose contact angle with water was reduced to 16 degrees by acid immersion. There was a practical problem with snow and snow.

Test example 10

The super-water-repellent aluminum plate obtained as in Example 3 was processed as shown in FIG. 8, and further placed in a container shown in FIG. 9 in block ice (2 (^ square), coarse ice (length 1 cm). ) Or snow, put a super water-repellent aluminum plate on top of it, and gradually remove the container with block ice (2 cm square), coarse ice (about lcm in length), or snow. tilt go, angle _S when the super water-repellent aluminum plate begins to slip _|, was measured _P, on ice (temperature

At 5 ° C), 0 _SI and _P started to slip at 30 degrees. Even on coarse ice (temperature 5 ° C), it slipped at 0 _SI , _P or 30 degrees, and on snow (temperature 2 ° C), it slipped even at the measurement limit of 80 degrees.

As a comparative example, was a similar experiment with a flat aluminum plate, 6 _{sli P} is 8 degrees on ice, 0 _{sll P} is 7 degrees in the coarse ice and the snow 0 _{sli P} 1 2-1 3 Degree. Furthermore, was subjected to the same tests against superhydrophilic aluminum plate contact angle against water by immersing 3 hours in an alkaline aqueous solution as a comparative example was reduced to 3 ° or less, 0 _{sl iP} value Although it has a large anti-slip effect, ice and snow adhered to the surface, and there was a practical problem. The secondary aluminum © irregular structure of厶板surface width. 1 to 2 0 m, height 2 m, 1 real surface area per cm ² 4. 3 cm ^2, the contact area 0.0 0 1 or Ah rigid l cm ² 5 was cm ^2.

Test example 1 1

The super-water-repellent iron plate obtained as in Example 4 was processed as shown in FIG. 8, and further, block ice (2 cm square), coarse ice (about lcm in length), or snow was placed in the container shown in FIG. Put the super water-repellent iron plate on this. Then, gradually tilt the container containing block ice (2 cm square), coarse ice (about lcro in length), or snow, and measure the angle 0 _{S 1} , _P when the super water-repellent iron plate starts to slide. However, on ice (temperature 5 ° C), _s , _{i P} began to slip when the temperature exceeded about 30 degrees. Even on coarse ice (temperature 5 ° C), S _SI and _P started to slide at 30 ° C, and on snow (temperature 2 ° C), they did not slip even at the measurement limit of 80 ° C.

As a comparative example, a similar experiment was performed on a flat iron plate. On ice, e _sl and _P are less than 10 degrees, on coarse ice 0 _SI and _P are 7 degrees, and on snow 6 » _{sl iP} is 10 to 1 It was twice. In addition, when the contact angle with water by immersing in saline as a comparative example having conducted the same test against reduced iron up to 3 degrees or less, the value of theta _s, ip is greater the slip stopping effect However, ice and snow adhered to the surface, causing a practical problem. Bumpy structure of the iron plate surface, the width from 0.5 to 3 0〃M, height 2~2 0 zm, 1 cm ² Ah actual surface area of the or 1 3. 7 cm ^2, the contact area per rigid 1 cm ² 0 0.05 cm ² .

Test example 1 2

The super-water-repellent zinc plate obtained as in Example 5 was processed as shown in FIG. 8 and further placed in a container shown in FIG. 9 in block ice (2 cm square), coarse ice (about lcm in length), or Put snow in it and place a super water-repellent zinc plate on it. Then, gradually tilt the container containing block ice (2 cm square), coarse ice (about 1 cm long), or snow, and set the angle 0 _S when the super water-repellent zinc plate starts to slide. As a result of measurement, on ice (temperature 5 ° C), it started to slip at e _sl , _P or 30 degrees. Even on coarse ice (temperature 5 ° C), 0 _{sli P} starts to _{slide at} 30 degrees, and on snow (temperature At 2 ° C), it did not slip even at the measurement limit of 80 degrees.

As a comparative example, was a similar experiment with a flat zinc plate, the ice 0 _{sl lP} is

At 10 degrees, S _{sli P} was 7 degrees on coarse ice and 0 _{sli P} was 10 to ₁₂ degrees on snow. As a comparative example, a similar test was performed on a hydrophilic zinc plate having a microstructure, and although the value of 0 _{sli P} was large and had an anti-slip effect, ice and snow adhered to the surface. Les, there was a practical problem.

Test example 1 3

The super-water-repellent aluminum plate obtained as in Example 6 was processed as shown in FIG. 8, and further placed in a container shown in FIG. 9 with block ice (2 cm square) and coarse ice (about 1 cm long). ) Put snow or snow and put super water-repellent aluminum plate on it. Then, gradually tilt the container containing block ice (2 cm square), coarse ice (about 1 cm in length), or snow, and set the angle 0 _S , _{1 P} when the super water-repellent aluminum plate starts to slide. was measured on ice (temperature one 5 ° C) in 0 _{S li P} began slipping in 2 8 °. Coarse ice (temperature one 5 ° C) at 0 _{S,, P} is Suberidashi 3 twice, snow (temperature 2 ° C) in an even slip et become 8 0 degrees is the measurement limit Kaka ivy.

As a comparative example, a similar experiment was performed on a flat aluminum _plate.On ice, 0 _{sli P} was 8 degrees or less, on coarse ice 0 _S or _P was 7 degrees or less, and on snow 0 _sl and _P was 12 to 12 degrees. 13 degrees. As a comparative example, a similar test was performed on an aluminum plate having a contact angle with water of 3 ° or less by forming a microstructure on the surface.The values of S _s and _{i P} were large and the anti-slip effect was large. However, there was a practical problem with ice and snow adhering to the surface.

Example 7 and Comparative Example 4

1 H, 1 H, 2 H, 2 H—Perfluorodetinol (manufactured by PCR) 100 g, 100 wt.% 98.5 g of polyphosphoric acid and 200 g of isopropyl ether in four ports The mixture was placed in a reaction flask, mixed, heated to 70 ° C., and mixed for 12 hours. After cooling the reaction mixture to 60 ° C., 17 g of water was added and hydrolysis was carried out at 70 for 8 hours. After cooling to 30 ° C, getyl ether 350; ^, water 18 and ethanol 70 mil were added, and the mixture was shaken to extract phosphoric acid into the lower layer. After separating the lower layer from which the phosphoric acid was extracted, water 18 and 1N hydrochloric acid 2 were added to the upper layer and shaken, and the upper layer was washed. Upper layer Was removed and the solvent was distilled off to obtain 112 g of a white solid. The white solid contained 96.5% of 1H, 1H, 2H, 2H-perfluorodecyl phosphate (Compound 7a).

 Compound Ί a

0

 II

CF ₃ (CF ₂ ) ₈ CH ₂ CH ₂ -0-P-OH

 The liquid repellency treatment of the OH metal surface was performed as follows. Smooth aluminum plate, stainless steel plate 18 and zinc plate (manufactured by Nikola) with a size of 10 cm x 5 cm and a thickness of 1. Omm are immersed in a 2.0 wt% ethanol solution of compound 7a for 1 week at room temperature. After washing with ethanol, it was dried.

 The contact angle of the metal surface with respect to the liquid was measured using an optical contact angle meter (CA-A, manufactured by Kyowa Interface Science Co., Ltd.). That is, as shown in FIGS. 1 (a) and 1 (b), test sample 1 was placed on sample stage 2 of the above-mentioned optical contact angle meter, and the liquid was poured into syringe 3 for dropping liquid by 0.5 m. Then, a droplet 4 was formed at the tip of the syringe 3. The syringe 3 was slowly moved downward, and the droplet 4 was brought into contact with the test sample 1, and vibration was applied to place the droplet 4 on the test sample 1. At this time, the contact angle (0) between the droplet 4 and the test sample 1 was measured. The liquids shown in Table 1 were used, and commercial grade products were used as they were. Table 3 shows the measurement results of the contact angles of each liquid on an aluminum plate, a stainless steel plate 18, and a zinc plate treated with liquid repellency with compound 7a.

As a comparative example, Table 3 shows the measurement results of various liquids on an untreated smooth aluminum plate, stainless steel plate 18, and zinc plate (manufactured by Nilaco). 2 ^-Table 3 Aluminum plate Stainless steel 1 8 Zinc plate Untreated compound 7a treatment Untreated compound 7a treatment Untreated compound 7a treatment Solvent contact angle Contact angle Contact angle Contact angle Contact angle Contact angle Hexane 6.5 33.3 8.5 28 3> 28.5 octane 5 45.8 10.6 52.6 3> 48

-Factory 6.2 62.3 13 60.5 3> 64 Dodecane 6.3 75.7 17.6 72.6 5.5 69.4 Hexadene 3.8 86.4 20.9 77 12.4 76.2 Octanol 3.6 72.8 19.2 64.6 10.5 77.3 Dodecanol 16.4 90 25.4 79.6 20.7 78.4 Cyclohexanol 19.3 84.4 28.3 90 27.5 87 Diethylene glycol 60.7 102.4 56.4 101.2 62.8 108.6 Glycerin 75.6 129.5 82.3 118.4 46.4 138.2 Methyl myristate 8.5 91.6 22.2 81.6 19.2 71.5 Getyl glucurate 16.4 88.8 26.5 77.8 30 76 Getyl adipate 29.6 96.5 48.4 66.1 35 82.4 Dimethyl malonate 47.5 101.2 52 83.2 35.4 93.2 Monoacetin 45.9 110 57.5 97.1 49.5 94.6 Water 76.4 114.4 77.8 123 87.8 117.3

The contact angles of various liquids on aluminum plate, stainless steel plate 18 and zinc plate treated with compound 7a are greatly increased compared to untreated ones, and liquid repellency is obtained by treatment with compound 7a. It can be seen that is greatly improved.

Example 8

Size: 10 cm x 5 cm, Thickness: 1.0 Maraudal zinc plate (manufactured by Nilaco Co., Ltd.) Two DC plates are placed opposite to each other at a distance of 5 cm in a 0.01 N aqueous zinc chloride solution, and a DC stabilized power supply (GPS, manufactured by INTEX Co., Ltd.), and electricity was supplied at an electrode current density of 1 mAZcm ² for 3 hours. As a result, zinc was deposited on the zinc plate surface of the cathode, and a fine uneven structure was formed on the surface. The zinc plate was washed with distilled water, dried, and its microstructure was observed with a scanning electron microscope (S-400, manufactured by Hitachi, Ltd.). A structure was formed. Height. 2 to 5 0 m of the concavo-convex structure, the width from 0.5 to 2 5〃M, 0 the actual surface area of 1 cm ² per in flat field 1. 2 cm ^2, the contact surfaces product zeros. 0 4 It was 3 cm ^2. The zinc plate having the fine concavo-convex structure was immersed in a 2.0% by weight solution of compound 7a in ethanol at room temperature for 1 week, washed with ethanol, and dried. The contact angles of the zinc plates treated in this way with various liquids shown in Table 4 were measured. The results are shown in Figure 11 in the form of a dysman plot. At the same time, in FIG. 11, the outline of the flat zinc plate subjected to the lyophobic treatment with the compound 7a shown in Example 7 is also indicated by white symbols.

Table 4 Liquid surface tension (dyne / cm)

 Hexane 18.4

 Octane 21.6

 Saturated hydrocarbon decane 23.8

 Dodecane 25.4

 Hexadene force 27.5

 Okyu Noor 27.5

 Dodecanol 29.4

 Alcohol Cyclohexanol 33.4

 Dethylene glycol 45.2

 Glycerin 63.4

 Methyl myristate 29.4

 Ester glutyl citrate 32.3

 Getyl adipate 36.0

 Monoacetin 41.8

Water Water 72.3 As shown in Figure 11, treating a smooth zinc plate with compound 7a on a zinc plate with fine pits and projections improves the lyophobic property much more than treating it with compound 7a. _C, that is, the value of cos 6 in the uneven zinc plate is shifted to a largely negative direction as compared with the value of cos 0 in the smooth zinc plate. Moreover, this shift not only occurs for liquids with a surface tension of cosS <0 as predicted from the conventional wetting theory, but also surprisingly, for liquids with a surface tension of cos0> 0. It's all up. That is, even if the zinc surface treated with the compound 7a is originally lyophilic, the surface of the zinc becomes lyophobic due to the unevenness of the surface. This has resulted in zinc surfaces that are repellent to a very wide range of liquids.

Example 9

Two flat aluminum plates of 10 cm x 5 cm and thickness of 1.0 cm (made by Niraco Co., Ltd.) are placed facing each other in a 1 N sulfuric acid solution at a distance of 5 cm, and a DC stabilized power supply ( Intex Corporation, GPS - 3 0 3 0) the electrode current density 1 OmAZcm ² in 3-hour conduction were _c using the result, aluminum is eluted from the surface of the aluminum plate of the anode, the fine uneven structure formed on a surface thereof . Observation of the fine structure using a scanning electron microscope (S-400, manufactured by Hitachi, Ltd.) revealed that a fine uneven structure was formed as shown in Fig. 12. I was The height of the unevenness was 2 m, the width was 1 to 5 m, the actual surface area per 1 cm ^{2 in} a planar view was 16.2 cm ² , and the contact area was 0.002 3 cm ² .

 The aluminum plate having the fine concavo-convex structure was immersed in a 2.0% by weight ethanol solution of compound 7a at room temperature for 1 week, washed with ethanol, and dried. The contact angles of the aluminum plate treated in this manner with various liquids shown in Table 4 were measured. The results are shown in Figure 13 in the form of a dysman plot. At the same time, in FIG. 13, the data of the smooth aluminum plate subjected to lyophobic treatment with the compound 7a shown in Example 7 is also shown by a white symbol.

As shown in Fig. 13, treating a smooth aluminum plate with Compound 7a on an aluminum plate with fine irregularities has a much higher lyophobic property than treating it with Compound 7a. I have. That is, the value of C OS 0 in the aluminum plate of the irregularity, the value difficulty of _C os 0 flat smooth a Aruminiumu plate label is greatly shifted to a negative one. Furthermore, this shift not only occurs for liquids with a surface tension of COS 0 or 0 as predicted from the conventional wetting theory, but also surprisingly, liquids with a surface tension of cos S> 0 Has also been raised. That is, even if the aluminum surface treated with compound 7a is originally lyophilic, the aluminum surface will exhibit liquid repellency due to the unevenness of the surface. This has made it possible to obtain an aluminum surface that is lyophobic for a very wide range of liquids. Industrial applicability

 According to the present invention, excellent liquid repellency can be imparted to various metal surfaces by a simple operation.

 In addition, the metal material of the present invention is excellent in snow resistance and ice resistance: shelves and luggage in freezing warehouses, antennas, cables, steel towers, jigs for civil engineering machinery, houses, roofs, road signs, etc. It can be widely used as a material for bulletin boards.

Furthermore, the anti-snow and anti-slip metal material of the present invention has high friction on the ice and snow surface, despite having no sharp projections, so that shelves, luggage, shoes, and vehicle wheels in a freezing warehouse can be used. It can be used as a non-slip material for surfaces that come into contact with metal such as ice or snow. In addition, icing and snow accretion on the surface of the metal material of the present invention are extremely small, Water does not cover the surface even if ice and snow melts at zero or more, and does not damage the road or floor.

 Furthermore, if the liquid-repellent metal material obtained by the present invention is used for the air-side heat transfer surface of a heat exchanger such as an air conditioner or a refrigerator, it is possible to reduce the decrease in heat exchange efficiency due to frost formation. Can be.

 Further, the liquid-repellent metal material obtained by the present invention may be used for a liquid-contacting surface of a pipe (flowing liquid pipe) through which liquid flows, such as a water pipe, a funnel, and a pouring port for various liquids. In addition, it is possible to obtain a flow tube in which the flow of the liquid is fast and the liquid does not remain after use.

 Further, the liquid repellent metal material obtained by the present invention is used for various electric devices such as a portable or indoor video, television, radio, etc., or an external part of a precision device such as a camera or a clock, thereby obtaining a device. The inside can be shielded from tap water, rainwater, seawater, snow, etc. to prevent electric shock, short circuit or rust. In addition, this unit may be used for electrical outlets such as outlets, sockets, water heaters, coffee makers, etc. By using the liquid-repellent metal material obtained by the present invention, water can be removed from the surface of the member, and the risk of short-circuit and electric shock can be eliminated.

 In addition, by using the liquid-repellent metal material obtained by the present invention around handrails, doorknobs, and elevator push buttons, fingerprint dirt can be prevented.

 In addition, by using the liquid-repellent metal material obtained by the present invention in a part of an accessory or a watch that directly touches the human skin, it prevents sweat from adhering, and further prevents rash and rash. be able to.

Claims

The scope of the claims

1. A liquid repellent material is coated on all or part of the metal surface, which has a fine uneven structure on the surface and has a contact angle with water of 30 degrees or less. Liquid property imparting method.

 2. The width and height of the fine uneven structure is 1 ηπ! The liquid repellency imparting method according to claim 1, wherein the thickness is from 800 m to 800 m.

 3. The method for imparting liquid repellency according to claim 1, wherein the width and height of the fine irregularities are 1 nm to 300 μm.

4. The height of the fine uneven structure is 300 m or less, the actual surface area per 1 cm ² of the uneven structure in plan view is 3 cm ² or more, and a smooth rigid body is applied to the surface of the uneven structure. ^{2. The} method for imparting liquid repellency according to claim 1, wherein the contact area is 2 cm ² or less per 1 cm ^{2 of the} rigid body surface.

5. The height of the fine concavo-convex structure is 300 μm or less, the actual surface area per 1 cm ² of the concavo-convex structure in plan view is 3 cm ² or more and less than 20 cm ² , and the surface of the concavo-convex structure is smooth. ^{2. The} method for imparting liquid repellency according to claim 1, wherein a contact area of the rigid body is 2 cm ² or less per 1 cm ^{2 of the} rigid body surface.

 6. The method for imparting liquid repellency according to any one of claims 1 to 5, wherein the fine uneven structure is a fractal structure or a self-fine structure.

 7. Means for creating fine irregularities on the metal surface include polishing or cutting mechanical processing on the metal surface, immersing the metal surface in an acid or alkali solution, corroding the metal, and metal electrode The method for imparting liquid repellency according to any one of claims 1 to 6, wherein the method is a method using electrolysis or a method for producing a metal.

 8. A super-water-repellent metal material characterized by having a super-water-repellent surface formed by coating a water-repellent substance on a metal surface having a fine concavo-convex structure and a contact angle with water of 30 degrees or less.

 9. The metal material according to claim 8, which is a metal material that is resistant to snow and ice.

 10. The metal material according to claim 8, which is a non-skid anti-skid metal material.

1 1. The width and height of the fine uneven structure, 1 ηπ! Claim 8 to Claim 8 10. The metal material according to any one of items 10.

 1 2. The width and height of the fine uneven structure is 1 ηπ! The metal material according to any one of claims 8 to 10, wherein the thickness of the metal material is from 300 to 300 m.

13. The height of the fine uneven structure is 300 m or less, the actual surface area per 1 cm ² of the uneven structure in plan view is 3 cm ² or more, and a smooth rigid body is applied to the surface of the uneven structure. metallic material according to one of claims 8-1 0 contact area is less rigid surface 1 cm ² per 2 cm ² when the.

1 4. The height of the fine uneven structure is not more than 3 0 0 rn, a real surface area per uneven structure 1 cm ² in a plan view is less than 3 cm ² or more 2 0 cm ^2, the uneven structure surface The metal material according to any one of claims 8 to 0, wherein a contact area when a smooth rigid body is applied is 2 cm ² or less per 1 cm ^{2 of the} rigid body surface.

 15. The metal material according to any one of claims 8 to 14, wherein the fine uneven structure is a fractal structure or a self-fine structure.

 16. A method for imparting liquid repellency to a metal surface, which comprises coating the entire or a part of the metal surface with a fluoroalkyl phosphate compound.

 17. The method for imparting liquid repellency according to claim 16, wherein the fluoroalkyl phosphoric acid ester compound is a monofluoroalkyl phosphoric acid ester, a difluoroalkyl phosphoric acid ester or a salt thereof.

18. A super lyophobic metal material having a super lyophobic surface formed by coating a fluoroalkyl phosphate compound on the metal surface.

Amendment * Claims

[May 14, 1996 (14.05.96) Accepted by the International Bureau: Claims at the time of initial appearance 1–18 are replaced by amended claims 1–1 2 Has been replaced. (2 pages)]

1. The height of the uneven structure on the surface is 1 nm to 300 m, and the actual surface area per 1 cm ² of the uneven structure in a plan view is 3 cm ² or more and less than 20 cm ^2. has a fine uneven structure contact area is less rigid surface 1 cm ² per 2 cm ² when addressed flat smooth rigid to the surface, or all of the metal surfaces in contact angle with water becomes less than 3 0 degrees Is a method for imparting liquid repellency to a metal surface, characterized in that a liquid repellent substance is partially coated.

 2. The method for imparting liquid repellency according to claim 1, wherein the fine uneven structure is a flux structure or a self-affine structure.

 3. Means to create fine uneven structure on metal surface, method of polishing or cutting mechanical processing on metal surface, method of immersing metal surface in acid or alkali solution, method of corroding metal, 3. The method for imparting liquid repellency according to claim 1, wherein the method is used as an electrode, the method utilizing electrolysis, or the method of producing a metal.

 4. The method for imparting liquid repellency according to any one of claims 1 to 3, wherein the liquid repellent substance is a fluoroalkyl phosphate compound.

5. A height 1 nm~ 3 0 0 m of the concavo-convex structure, a real surface area or Ah uneven structure 1 cm ² in a plan view is less than 3 cm ² or more 2 0 cm ^2, the uneven structure surface water repellent material to the metal surfaces in contact angle becomes less than 3 0 ° contact area for water having a fine concave convex structure is 0. 2 cm ² or less per rigid surface 1 cm ² when addressed a smooth rigid A super-water-repellent metallic material having a super-water-repellent surface formed by coating the following.

 6. The metal material according to claim 5, which is a snow- and ice-resistant metal material.

 7. The metal material according to claim 5, which is an anti-snow metal material against ice and snow.

 8. The metal material according to any one of claims 5 to 7, wherein the fine uneven structure is a flux structure or a self-affine structure.

 9. The metal material according to any one of claims 5 to 8, wherein the water repellent substance is a fluoroalkyl phosphate compound.

 10. A method for imparting liquid repellency to a metal surface, comprising coating a fluoroalkyl phosphate compound on all or a part of the metal surface.

-32-Amended paper (Convention *)

11. The claim wherein the fluoroalkyl phosphate compound is a monofluoroalkyl phosphate, a difluoroalkyl phosphate or a salt thereof.

10. The method for imparting liquid repellency described in 10 above.

 12. A super-liquid-repellent metal material having a super-liquid-repellent surface formed by coating a fluoroalkyl phosphate compound on a metal surface.

-33-Paper captured (Article Articles of the Convention)