JP2000313997A - Composite plating solution and formation of composite plating coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite plating coating film exhibiting high water repellency and moreover stable for friction. SOLUTION: The composite plating soln. contains metallic salt and water repellent fine particles. Each water repellent fine particle contains a core and a water repellent layer covering the surface, and the water repellent layer is formed by using pitch fluoride having surface-active function. The composite plating coating film is formed by executing an electroless plating method or electrolytic plating by using the plating soln., further heat treatment may be added as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plating solution and a method for forming a plating film, and more particularly to a composite plating solution and a method for forming a composite plating film.

[0002]

2. Description of the Related Art As a film for imparting water repellency to a metal or resin substrate, a film made of a fluorine-based resin such as polytetrafluoroethylene is known. However, since the fluororesin hardly softens and flows, it is difficult to form a uniform coating on the inner surface of a fine metal tube or the surface of a member having a complicated uneven shape. Therefore, as a film capable of imparting uniform water repellency to the surface of a member having a complicated shape or the like, a composite plating film in which particles of a fluorine-based compound or particles treated with a fluorine-based compound are dispersed is used. Proposed.

For example, Japanese Patent Application Laid-Open No. 7-26397 discloses a composite plating film in which fine particles of a fluorine compound such as fine pitch fluoride are dispersed and eutectoid in a metal base material layer. This composite plating film has high water repellency because it contains fluorine-containing compound fine particles exhibiting high water repellency in the metal base material layer, and can be formed by a conventional plating method, and thus has a complicated shape. Can be evenly applied to the surface or the like of a member having.

In the case of forming a composite plating film as described above, usually, a metal salt for forming a metal base material layer, fine particles of a fluorine compound and fine particles of the fluorine compound are uniformly dispersed in water. A composite plating solution containing a surfactant is prepared, and a substrate is immersed in the composite plating solution to apply a plating method. However, since the composite plating film formed by this composite plating solution contains a surfactant, the use of fluorine compound fine particles often cannot exhibit the originally expected water repellency.

[0005] Further, in the above-mentioned composite plating film, when friction is applied, the fluorine-based compound fine particles dispersed in the metal base material layer easily fall off. Therefore, the composite plating film may contaminate the surrounding environment due to the fluorine-based compound fine particles that have fallen off, and can exhibit high water repellency in the initial stage of formation, but the water repellency gradually decreases when subjected to friction. It is expected to do.

An object of the present invention is to realize a composite plating film which exhibits high water repellency and is stable against friction.

[0007]

A composite plating solution according to the present invention contains a metal salt and water-repellent fine particles. The water-repellent fine particles have a core and a water-repellent layer that covers the surface of the core, and the water-repellent layer is formed using fluorinated pitch having surface activity.

[0008] Here, the core constituting the water-repellent fine particles is
For example, the surface has a functional group that can be chemically bonded to pitch fluoride. In this case, the functional group capable of chemically bonding to the pitch fluoride is, for example, an amino group, a hydroxyl group, an alcoholate group,
At least one selected from the group consisting of phenolate groups, alkali metal bases of acids, mercapto groups and epoxy groups
One. This functional group is provided on the surface of the core using, for example, a surface treatment agent.

The method for forming a composite plating film according to the present invention is a method for forming a composite plating film in which water-repellent fine particles are dispersed in a metal base material layer on a substrate. This forming method is formed by using a metal salt for forming a metal base material layer, a core and a water-repellent layer covering the surface thereof, and the water-repellent layer is formed using pitch fluoride having surface activity. And a step of immersing a substrate in the composite plating solution and applying a plating method to the substrate.

This forming method usually further includes a step of heat-treating the composite plating film obtained by the plating method.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The composite plating solution of the present invention comprises an aqueous solution in which a metal salt is dissolved and contains water-repellent fine particles. Here, the metal salt is a material for forming a metal base material layer of the composite plating film, for example, noble metals such as nickel, copper, zinc, tin, iron, lead, cadmium, chromium, gold and silver, And salts such as alloys thereof. Salts of such metals include chloride salts such as nickel chloride,
Examples thereof include carbonates such as nickel carbonate and sulfamate salts such as nickel sulfamate.

On the other hand, as shown in FIG.
Has a core 2 and a water-repellent layer 3 covering the surface thereof.

Here, the core 2 is made of an organic material such as a resin,
It is made of an inorganic material such as metal, ceramic, and mineral, and is formed into various shapes such as a sphere, a column, and a scale. In FIG. 1, the core 2 is shown in a spherical shape, but this does not limit the present invention.
When such a core 2 is formed using a resin as an organic material, for example, a suspension-polymerized polyamide resin (nylon) or a polyurethane resin is used from the viewpoint that the water-repellent fine particles 1 are easily formed into fine particles. be able to. When the core 2 is made of an inorganic material,
Specific examples of available metals include aluminum, and specific examples of ceramics include silicon carbide.
Further, specific examples of the mineral include talc, silica, and mullite.

From the viewpoint of enhancing the stability of the composite plating film against thermal shock and from the viewpoint of the temperature range in which the composite plating film is used, the material constituting the core 2 is a metal base material layer formed of the above-described metal salt. It is preferable to select in consideration of the difference in the thermal expansion coefficient between the two.

The core 2 has on its surface a functional group capable of undergoing a chemical bond reaction with a pitch fluoride having surface active ability described later, which constitutes the water-repellent layer 3. Examples of the functional group capable of exerting such a function include an amino group, a hydroxyl group, an alcoholate group, a phenolate group, an alkali metal base of an acid, a mercapto group, and an epoxy group. The core 2 may have two or more of these functional groups.

Particularly preferred of the above functional groups are:
An amino group having high reactivity with fluorinated pitch. Here, the amino group may be any of primary, secondary, or tertiary amino groups represented by the following formula. Further, the amino group here is a concept including an amide group and a urethane bond.

[0017]

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Examples of the alkali metal base of an acid include a sodium base and a potassium base of a carboxylic acid and a sulfonic acid. Further, the above-mentioned epoxy group is a concept including a glycidyl group.

The above-mentioned functional groups may be those possessed by the organic or inorganic material constituting the core 2 or may be those imparted to the surface of the core 2 using a surface treating agent. .

In the former case, examples of the organic material having an amino group include polyamine resin, polyethyleneimine resin, poly (trimethyleneimine) resin, polyamide resin, polypeptide resin, polyurethane resin, polyurea resin, polyimide resin, and polyimidazole. Nitrogen-containing resins such as resin, polyoxazole resin, polypyrrole resin, polyaniline resin, aramid resin, and polyacrylamide resin can be exemplified. Examples of the organic resin having a hydroxyl group include a phenol resin and cellulose. As the organic resin having an alcoholate group, an ion exchange resin can be exemplified. Examples of the organic resin having a phenolate group include a phenol resin which has been subjected to an alkali treatment. Examples of the organic resin having an alkali metal base of an acid include an ion exchange resin. Examples of the organic resin having a mercapto group include thiochol.

On the other hand, in the latter case (when a surface treatment agent is used), a core 2 having a chemical structure capable of chemically bonding to a surface treatment agent for providing a desired functional group on the surface is used. . Here, the chemical structure capable of reacting with the surface treatment agent includes, for example, functional groups such as a hydroxyl group, a carboxyl group and a carbonyl group, metal oxides, and S
A silicon oxide such as iO ₂ can be used. The core 2 having such a chemical structure on its surface includes, for example, those formed using silica as a material.

The surface treating agent for imparting a desired functional group to the core 2 includes a chemical structural portion present on the surface of the core 2 and capable of reacting with the above-mentioned chemical structure, and a functional group to be imparted to the core 2. It has. The surface treatment agent is not particularly limited as long as it satisfies such conditions. Examples of the surface treatment agent include a silane coupling agent having a functional group to be provided to the core 2, a titanate coupling agent, and an organochrome. Examples include a system coupling agent.

For example, when the functional group to be provided to the core 2 is an amino group, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyl-trimethoxysilane, Silane coupling agent having an amino group such as n (dimethoxymethylsilylpropyl) -ethylenediamine, titanate coupling agent having an amino group such as isopropyltri (N-amidoethylaminoethyl) titanate, represented by the following structural formula An organic chromium-based coupling agent having an amino group such as a chromic chloride-based compound can be used.

[0024]

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When the functional group to be imparted to the core 2 is an epoxy group, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- (3,4-epoxycyclohexyl) ethyl
Glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and the like can be used. Two or more of these surface treatment agents may be used in combination.

When a predetermined functional group is imparted to the surface of the core 2 by using the above-mentioned various surface treating agents, the core 2 is treated with the surface treating agent. As a method of treating the core 2 using the surface treatment agent, a method of dipping the core 2 in the surface treatment agent, a method of applying the surface treatment agent to the core 2, and the like can be adopted. When applying the surface treatment agent, for example, a brush, various rollers, a spray, or the like can be used. Further, a method of wet pulverizing a material for forming the core 2 in the presence of a surface treatment agent may be employed.

The treatment temperature at the time of treating the core 2 with the above-mentioned surface treatment agent varies depending on the type of the surface treatment agent and the like, and is not particularly limited. . Further, the treatment time varies depending on the type of the surface treatment agent and the treatment method of the surface treatment agent.
Preferably, it is set to 24 hours.

Core 2 treated with the above surface treatment agent
Is preferably sufficiently dried before moving to a step for forming the water-repellent layer 3 described later. The drying condition of the core 2 depends on the type of the core 2 and the heat-resistant temperature, but is usually 60 to
It is preferable to set the temperature at 150 ° C. for 1 to 24 hours. Such a drying treatment of the core 2 may be performed under reduced pressure.

On the other hand, the water-repellent layer 3 is formed by using fluorinated pitch having surface activity. Here, the fluorinated pitch is a known substance that can be produced by fluorinating the pitch using a fluorine gas.
No. 2-275190.

The pitch used for producing such a fluorinated pitch generally has a layer structure in which aromatic condensed six-membered ring planes are laminated while being cross-linked by an aliphatic hydrocarbon group such as methylene. Usually, petroleum distillation residue,
Naphtha pyrolysis residue, ethylene bottom oil, coal liquefied oil and petroleum or coal heavy oil such as coal tar are distilled to remove low boiling components having a boiling point of less than 200 ° C.,
These are those synthesized by condensation of naphthalene or the like, and those further subjected to heat treatment or hydrogenation treatment. Specifically, isotropic pitch, mesophase pitch, hydrogenated mesophase pitch, mesocarbon microbeads composed of mesophase spheres formed after distilling petroleum-based or coal-based heavy oil to remove low-boiling components, etc. Can be mentioned.

When producing the desired fluorinated pitch using the above-mentioned pitch, the pitch is directly reacted with fluorine gas. The temperature at the time of this reaction is preferably set to about 0 to 350 ° C., and more preferably to the softening point of the pitch or lower. In addition, the fluorine gas pressure during the reaction is not particularly limited, but is generally preferably set to 0.07 to 1.5 atm. Note that, as the fluorine gas, a gas diluted with an inert gas such as nitrogen, helium, argon, or neon may be used.

Preferable fluorinated pitches usable in the present invention are substantially composed of carbon atoms and fluorine atoms, and the atomic ratio of fluorine to carbon (fluorine / carbon) is, for example, 0.5 to 1. It is about 8 powders. Such a fluorinated pitch exhibits the following characteristics (a), (b), (c) and (d).

(A) In powder X-ray diffraction, 2θ = 13
A peak with the maximum intensity is shown near ゜, and a peak with a smaller intensity than the maximum intensity peak is shown near 2θ = 40 °. (B) 290.0 ± 1.
The peak corresponding to CF at 0 eV and 292.5 ± 0.
A peak corresponding to CF ₂ is shown around 9 eV, and the ratio of the intensity of the peak corresponding to CF ₂ to the peak corresponding to CF is about 0.15 to 1.5. (C) A film can be formed by vacuum distillation. (D) The contact angle with water at 30 ° C. is 141 ± 8.
°.

In the present invention, pitch fluoride of a transparent resin can be used. The pitch of the fluorinated pitch in the form of a transparent resin is, for example, about 0.1 to 3 ° C./min, preferably 0.5 to 1.5 ° C. in a fluorine gas atmosphere.
The temperature is raised to about 250 to 400 ° C. at a rate of about 250 ° C./minute, and the temperature is raised for a predetermined time, for example, about 1 to 18 hours, preferably
It can be produced by reacting for about 12 hours. According to this method, for example, a fluorinated pitch in the form of a transparent resin having the following characteristics can be obtained.

F / C atomic ratio: 1.5 to 1.7 Light transmittance (250 to 900 nm): 90% Molecular weight: 1,500 to 2,000 Softening point: 150 to 250 ° C.

As the fluorinated pitch, the powdery powder and the transparent resinous powder described above may be used in combination.

The above-mentioned fluorinated pitch has, in its structure, a chemical structural part capable of directly reacting with the above-mentioned functional group on the core 2 side, for example, a monofluorocarbon structure or a carboxylic acid anhydride structure. Have. Here, the monofluorocarbon structure refers to a carbon-fluorine bond structure in which one fluorine atom is bonded to a carbon atom, and specifically refers to a structure represented by the following structural formula. Such a monofluorocarbon structure also includes an acid fluoride structure. Incidentally, the monofluorocarbon structure has high reactivity with the amino group, hydroxyl group and mercapto group among the above-mentioned functional groups on the core 2 side.

[0038]

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The pitch fluoride having surface activity used in the present invention is obtained by reacting the above-mentioned pitch fluoride with a diamine compound. The diamine compound used here is not particularly limited as long as it has two amino groups, and is a variety of known compounds. Preferably, the diamine compound is represented by the following general formula (1). .

[0040]

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In the general formula (1), R represents an alkyl group having 1 to 3 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group or an iso-propyl group. When the carbon number of the alkyl group represented by R exceeds 3, the steric hindrance may make it difficult for the diamine compound to react with the fluorinated pitch. On the other hand, n has shown the integer of 2-5. When n is 1, the diamine compound becomes unstable and handling may be difficult. Conversely, if it exceeds 5, it may be difficult to obtain a fluorinated pitch having a high surface activity.

Particularly preferred among the diamine compounds represented by the general formula (1) are those in which the alkyl group represented by R is a methyl group and n is 3,
1,3-propanediamine.

When reacting the above-mentioned pitch fluoride with a diamine compound, usually, a solution is prepared by dissolving both in a suitable solvent, and both solutions are mixed to react the pitch fluoride with the diamine compound. Let it. The solvent for dissolving the pitch fluoride and the diamine compound is not particularly limited as long as both can be dissolved, and for example, alcohols, furans, and the like can be used.

The reaction temperature at the time of reacting the pitch fluoride and the diamine compound is usually preferably set at room temperature to 100 ° C., more preferably at 10 to 40 ° C., and preferably at 10 to 20 ° C. More preferably, When the reaction temperature exceeds 100 ° C., the product may be tarred. In the above reaction, it is preferable to set the amount of the diamine compound to be substantially equivalent to the pitch fluoride. However, the amount of the diamine compound to be used is generally larger than that of the pitch fluoride. It is preferable to set

In the case where the water-repellent layer 3 is formed on the surface of the core 2 by the above-mentioned surface-active fluorinated pitch (hereinafter sometimes referred to as modified fluorinated pitch), the modified fluorinated pitch is used as a solvent. A dissolved solution was prepared, and this was
Apply to. As a coating method, for example, a method of spraying a solution of modified pitch fluoride onto the core 2 or a method of dipping the core 2 in the solution can be adopted.

The solvent for dissolving the modified fluorinated pitch is not particularly limited as long as it can dissolve the modified fluorinated pitch, but usually a fluorine-based solvent is preferably used. Here, as the fluorine-based solvent, for example, perfluorodecahydrophenanthrene, perfluorodecalin, perfluoro-1-methyldecalin, perfluorodimethylnaphthalene, perfluoro-1,3-dimethylcyclohexane, 2,5 Dichlorobenzotrifluoride, chloropentafluorobenzene, 1,1,2-trichloro-1,2,2-trifluoroethane (for example,
Asahi Glass Co., Ltd. product name "FLONSOLV"), hexafluorobenzene, 1.3-ditrifluoromethylbenzene, 2,2,2-trifluoroethanol, trifluoromethylbenzene, Sumitomo 3M Co., Ltd. product name "PF5052"", A perfluoro-2-normal butylfuran-based solvent (for example, trade name" Fluorinert FC75 "manufactured by Sumitomo 3M Limited), a trisperfluoro n-butylamine-based solvent (for example, trade name manufactured by Sumitomo 3M Limited," Fluorinert " FC43 ″), a trisperfluoroalkylamine-based solvent (for example, “Fluorinert FC3” manufactured by Sumitomo 3M Limited)
283 "," Fluorinert FC40 "and" Fluorinert FC70 "), Galden DO2 (trade name) manufactured by Montezison Japan Co., Ltd., and chlorofluorocarbon (for example, Freon 11 manufactured by Asahi Glass Co., Ltd.)
3 ″). Among these fluorine-based solvents, particularly preferred are chloropentafluorobenzene, hexafluorobenzene, and trisperfluoroalkylamine-based solvents in that modified pitch fluoride is easily dissolved. It is.

When the modified pitch fluoride is used by dissolving it in a solvent, the concentration of the modified pitch fluoride is usually 0.01 to 5%.
0% by weight, preferably 0.1 to 2% by weight.
More preferably, it is set to be 0% by weight. When the concentration is less than 0.01% by weight, for example, when the water-repellent layer 3 is formed on the core 2 by immersion as described later, it is necessary to set the immersion time to be long. Therefore, it may be difficult to form the required water-repellent layer 3.
On the other hand, if the content exceeds 50% by weight, the liquid viscosity of the modified pitch fluoride solution may be too high, which may make handling difficult. In some cases, it is difficult to form a uniform water-repellent layer 3 with respect to 2.

The particle size (average particle size) of the water-repellent fine particles 1 is not particularly limited, but generally, the metal base material layer of the composite plating film to be formed by using the composite plating solution of the present invention. Preferably, the thickness is set smaller than the thickness. When the particle size exceeds the thickness of the metal base material layer, when friction is applied to the composite plating film, the water-repellent fine particles 1 easily fall off the metal base material layer. Incidentally, the preferable range of the particle size of the water-repellent fine particles 1 is usually 0.01 to 20 μm,
1-5 μm is more preferred. In addition, the water-repellent fine particles 1
In order to ensure uniform dispersibility in the metal base material layer,
It is preferable to use those classified so as not to include coarse particles having a particle size of 20 μm or more.

The composite plating solution of the present invention can be produced by preparing an aqueous solution in which the above-mentioned metal salt is dissolved in water, and adding the above-mentioned water-repellent fine particles 1 to the aqueous solution to be uniformly dispersed. The concentration of the metal salt in the aqueous solution prepared here is usually preferably set to 30 to 60% by weight. When the concentration of the metal salt is less than 30% by weight, it may be difficult to form a metal base material layer having a required thickness. vice versa,
If the content exceeds 60% by weight, the viscosity of the composite plating solution may increase, and it may be difficult to uniformly disperse the water-repellent fine particles 1.

The content of the water-repellent fine particles 1 in the composite plating solution of the present invention is preferably set so that the volume fraction of the water-repellent fine particles 1 in the composite plating film is 1 to 50%. It is more preferable to set the volume fraction to 〜40%, but usually to 5 to 100 g / l, preferably 10 to 80 g / l, such a volume fraction can be achieved.

The composite plating solution of the present invention may contain various additives which can be usually added to the plating solution, such as a primary brightener, a secondary brightener, and a pigment for coloring the composite plating film, in addition to the above-mentioned various components. It may contain an agent.

The composite plating solution of the present invention can be produced by adding and mixing and dispersing the water-repellent fine particles 1 and other additives into an aqueous solution in which the above-mentioned metal salt is dissolved. Here, since the water-repellent fine particles 1 have the surface-repellent layer 3 made of fluorinated pitch as described above, the water-repellent fine particles 1 can be added to the aqueous solution without adding another surfactant. It can be uniformly and stably dispersed.

When a composite plating film is formed using the above-described composite plating solution, a predetermined base material is immersed in the composite plating solution prepared as described above, and a plating method is applied to the base material. Apply.

At this time, it is preferable that the composite plating solution is sufficiently stirred so that the water-repellent fine particles 1 contained in the composite plating film are evenly and uniformly dispersed in the metal base material layer. The stirring method is not particularly limited, but various known methods such as screw stirring and stirring with a magnetic stirrer can be adopted. In addition, as the plating method, a known electroless plating method or electrolytic plating method can be adopted. The plating conditions at this time can be set in the same manner as those employed in a general composite plating method. Specifically, the solution temperature, pH value, current density, and the like can be appropriately set according to the properties of the base material, the type of the composite plating solution, and the like.

In such a method for forming a composite plating film, the metal salt contained in the composite plating solution is reduced to a metal, and the metal is electrodeposited on the substrate. Thereby, a metal base material layer is formed on the base material. At this time, the water-repellent fine particles 1 contained in the composite plating solution are simultaneously eutectoid and uniformly dispersed in the metal base material layer. Thereby, a target composite plating film is formed on the base material.

It is preferable that the composite plating film thus formed is further heat-treated. By performing such a heat treatment, the water repellency of the composite plating film can be further increased. In this heat treatment, it is usually preferable to set the processing temperature to 150 to 300 ° C. and the processing time to 30 minutes to 2 hours. When the heat treatment temperature is lower than 150 ° C., it is necessary to set a long heat treatment time in order to obtain a sufficient heat treatment effect, which is not efficient. Conversely, if the processing temperature exceeds 300 ° C., the composite plating film may be deteriorated.

FIG. 1 shows a conceptual diagram (longitudinal sectional view) of the composite plating film formed as described above. In the figure, a composite plating film 10 is formed on a base material S and mainly includes a metal base material layer 11 and a large number of water-repellent fine particles 1 dispersed and eutectoid in the metal base material layer 11. ing. Here, some of the large number of water-repellent fine particles 1 partially protrude from the surface of the metal base material layer 11.

The substrate S on which such a composite plating film 10 is formed generally needs to be imparted with water repellency by the composite plating film 10, and is, for example, as follows.

A member requiring rust prevention. For example, various building materials and ship materials. ◎ Materials that may cause inconvenience if snow or icing occurs. For example, ice plates, transmission lines, parabolic antennas, etc. ◎ Materials that are required to have stain resistance, oil repellency, heat scorch, etc. For example, the inner surface of a dishwasher, the inner surface of a washing machine tank, a range hood, a ventilation fan, a table stove top plate, a table stove juice saucer, an oven plate, a grilled iron plate, a roster,
Genghis Khan hot pot, frying pan, goku, grill, gas stove, oven, microwave oven, rice cooker, barbecue stove, hot plate, pot, oven toaster, electric pot, electromagnetic induction heater, system kitchen top plate, sink, faucet, Mixing faucet, gas pipe inner and outer coats, etc. ◎ Materials requiring dew condensation prevention. For example, bathroom interior materials. ◎ Materials requiring water repellency and antifouling properties. For example, a bathtub. ◎ A member that is inconvenient if thermal conductivity is impaired. For example,
Exhaust top, heat exchanger fins, carbon fiber surface coat, carbon material coat, LNG vaporizer evaporator plate, copy roller, etc. ◎ Materials requiring mold release properties. For example, a mold. ◎ A member that requires water repellency and ice repellency. For example, parts for aircraft and helicopters. ◎ Materials that require slidability. For example, gas valve inner surface coating. ◎ A member that requires good liquid drainage. For example, liquid supply tubes such as micro syringe needles, pipettes, dispensers, separating funnels and general nozzles.

The specific material constituting the base material S is not particularly limited as long as it can be applied with the electroplating method. Examples of the material include copper, stainless steel, general steel, aluminum and the like. Various metals such as aluminum alloys, and carbon materials such as carbon plates and graphite plates.

In the base material S, in order to enhance the adhesion with the composite plating film 10, a portion where the composite plating film 10 is formed may be roughened in advance into fine irregularities. As such a method of surface roughening, a method of chemically treating the substrate S using an aqueous solution of an etching agent such as hydrofluoric acid, ammonium fluoride, or hydrochloric acid, or a shot blasting treatment, a sand blasting treatment, or a liquid honing Processing and mechanical processing methods such as polishing using steel wire or steel wool can be employed.

The substrate S may be provided with a base plating layer such as a nickel plating layer or a copper plating layer on the surface on which the composite plating film 10 is formed.

The composite plating film 10 as described above can exhibit good water repellency due to the water repellent layer 3 of the water repellent fine particles 1 contained therein. Here, the water-repellent fine particles 1 in the composite plating solution are not dispersed by using a surfactant that causes the water-repellency of the composite plating film 10 to be disturbed.
Since the dispersion is dispersed by the surface activity of the pitch fluoride itself forming the water-repellent layer 3, the composite plating film 10
May exhibit high water repellency. Further, since the composite plating film 10 is formed by using a composite plating solution that does not require the use of a surfactant, the occurrence of unevenness and discoloration is small, and the finished condition, that is, the appearance is good.

Since the water-repellent fine particles 1 have the core 2 inside, they can be stably and firmly held in the metal base material layer 11. Therefore, the composite plating film 10
Since the water-repellent fine particles 1 hardly fall off from the metal base material layer 11 even when subjected to friction, there is little risk of contaminating the surrounding environment, and the water repellency can be maintained satisfactorily for a long time.

[0065]

EXAMPLES Production Example 1 (Production of Water Repellent Fine Particles) The surface of fine silica fine powder (trade name “Silica SO-C1” manufactured by Admatics Co., Ltd. ) having an average particle size of 0.2 μm was treated with amino groups. Silane coupling agent (N-β
(Aminoethyl) -γ-aminopropyltriethoxysilane: brand name “KBM60” manufactured by Shin-Etsu Chemical Co., Ltd.
3 ″), and then treated at 100 ° C.
For 1 hour.

On the other hand, a pitch fluoride having surface activity was prepared. Here, 200 g of powdered fluorinated pitch (prototype name “N-6” of Osaka Gas Co., Ltd.) was added to 200 ml.
Was dissolved in ethanol to obtain a pitch fluoride solution. Further, 5 g of N, N-dimethyl-1,3-propanediamine was dissolved in 200 ml of ethanol to obtain a diamine compound solution. Then, when the obtained pitch fluoride solution and the diamine compound solution are mixed at room temperature, the pitch fluoride and N, N-dimethyl-1,3-propanediamine react while generating heat, and a black-brown solid substance is formed. (A fluorinated pitch having surface activity) was obtained.

A hexafluorobenzene solution containing 6% by weight of the pitch fluoride having surface activity obtained as described above was prepared, and the fine silica fine powder treated with the silane coupling agent was immersed in the solution. And treated at 100 ° C. for 2 hours.
After that, when the fine spherical silica powder was crushed using a ball mill, water-repellent fine particles having silica as a core and a water-repellent layer made of pitch fluoride having surface activity on the surface thereof were obtained.

Production Example 2 (Production of Water-Repellent Fine Particles ) A pitch-fluorinated powder having the same surface activity as that used in Production Example 1 was prepared using fine nylon sphere fine powder having an average particle size of 5 μm (manufactured by Toray Industries, Inc.). It was immersed in a hexafluorobenzene solution containing 6% by weight, treated at 80 ° C. for 1 hour, and dried. As a result, water-repellent fine particles having a nylon sphere as a core and a water-repellent layer made of pitch fluoride having surface activity on the surface thereof were formed.

Examples 1 to 3 A nickel plating aqueous solution containing 360 g / l of nickel sulfamate, 45 g / l of nickel chloride and 30 g / l of boric acid was prepared. To this, the water-repellent fine particles obtained in Production Example 1 were added at a rate of 50 g / l and suspended to obtain a composite plating solution.

The plate-like substrate was immersed in the obtained composite plating solution and subjected to an electrolytic plating treatment to form a composite plating film on the plate-like substrate. Here, a stainless steel plate (SUS430) having a mirror surface was used as the plate-like base material, and the conditions of the plating treatment were set as follows.

PH: 4.1 Current density: 3, 5 or 7 A / dm ² Coating thickness: 10 to 13 μm

Examples 4 to 6 Example 1 was repeated except that the plate-shaped substrate was changed to a stainless steel plate (SUS430) subjected to sandblasting (# 80).
In the same manner as in cases Nos. 1 to 3, a composite plating film was formed.

Examples 7 to 9 The composite plating films obtained in Examples 1 to 3 were heat-treated.
The heat treatment conditions here were set at 250 ° C. for 30 minutes.

Examples 10 to 12 The composite plating films obtained in Examples 4 to 6 were heat-treated.
The heat treatment conditions here were set in the same manner as in Examples 7 to 9.

Examples 13 to 15 An aqueous nickel plating solution containing 360 g / l of nickel sulfamate, 45 g / l of nickel chloride and 30 g / l of boric acid was prepared. The water-repellent fine particles obtained in Production Example 2 were added and suspended at a rate of 50 g / l, and nickel carbonate was added to adjust the pH to 4.0 to 4.2. Obtained.

The plate-like substrate was immersed in the obtained composite plating solution and subjected to electrolytic plating to form a composite plating film on the plate-like substrate. Here, a stainless steel plate (SUS430) having a mirror surface was used as the plate-like base material, and the conditions of the plating treatment were set in the same manner as in Examples 1 to 3.

Examples 16 to 18 Example 1 was repeated except that the plate-like substrate was changed to a stainless steel plate (SUS430) subjected to sandblasting (# 80).
A composite plating film was formed in the same manner as in cases 3 to 15.

Examples 19 to 21 The composite plating films obtained in Examples 13 to 15 were heat-treated. The heat treatment conditions here were set at 250 ° C. for 1 hour.

Examples 22 to 24 The composite plating films obtained in Examples 16 to 18 were heat-treated. The heat treatment conditions here were set in the same manner as in Examples 19 to 21.

Comparative Example 1 In place of the water-repellent fine particles obtained in Production Example 1, pitch fluoride powder having an average particle size of 0.8 μm was added to the nickel plating aqueous solution at a rate of 70 g / l, and this was added to the nickel plating aqueous solution. (A cationic surfactant manufactured by Dainippon Ink Co., Ltd .:
A composite plating film was obtained in the same manner as in Examples 1 to 3, except that the dispersion was carried out using the trade name “150Br”).

Comparative Example 2 The composite plating film obtained in Comparative Example 1 was heat-treated. The heat treatment conditions here were set at 250 ° C. for 30 minutes.

Evaluation The contact angles and falling angles, Vickers hardness, and dynamic friction coefficients of the composite plating films obtained in Examples 1 to 24 and Comparative Examples 1 and 2 when distilled water was dropped were examined. Here, each evaluation was performed for the case of the composite plating film immediately after formation (immediately after formation) and the case of strongly wiping the surface 20 times using the product name “Kimwipe” manufactured by Jujo Kimberly Co., Ltd. (after the friction treatment). did. After the friction treatment, the state of the water-repellent fine particles or the pitch fluoride powder falling off was further examined. The method of each evaluation is as follows. The results are shown in Tables 1 and 2. Incidentally, a normal nickel plating film has a Vickers hardness of 250 to 40.
0Hv, and the dynamic friction coefficient is about 0.5.

(Contact angle) Evaluation was made using a contact angle meter ("CA-A type" manufactured by Kyowa Interface Science Co., Ltd.).

(Falling Angle) A water drop was dropped on the contact angle meter used in the measurement of the contact angle, the drop surface was gradually inclined from the horizontal plane, and the angle at which the water droplet flowed was defined as the falling angle.

(Vickers Hardness) Evaluation was made using a Vickers hardness tester (trade name “DVK-1” manufactured by Matsuzawa Seiki Co., Ltd.).

(Coefficient of dynamic friction) 15 cm having a plated surface
A plating plate having a size of 15 cm was fixed horizontally, and a plating plate having a size of 5 cm 5 cm having a similar plating surface was placed on the plating plate so that the plating surfaces faced each other. Then, 1cm on a 5cm x 5cm plating plate
A 00 g iron weight was fixed, a horizontal load was applied to the weight, and a load when the plated plate was slipping was defined as a dynamic load. From this dynamic load, the dynamic friction coefficient was determined according to the following equation.

[0087]

(Equation 1)

(Dropping state) The adhesion state of the water-repellent fine particles or the pitch fluoride powder adhering to the Kimwipe was visually judged. The evaluation criteria are as follows. ：: No adhesion. Δ: There is slight adhesion. X: There is a large amount of adhesion.

[0089]

[Table 1]

[0090]

[Table 2]

[0091]

The composite plating solution of the present invention should be prepared without using a surfactant because the surface of the core contains water-repellent fine particles coated with fluorinated pitch having surface activity. Can be. Therefore, the composite plating film formed by the composite plating solution can exhibit high water repellency. Further, since the water-repellent fine particles contain the core, they do not easily fall off the composite plating film even when subjected to friction, and are stable against friction. For this reason, this composite plating film
There is little risk of contaminating the surrounding environment, and the water repellency is not easily reduced.

Further, since the method for forming a composite plating film according to the present invention uses the composite plating solution of the present invention, it is possible to form a composite plating film exhibiting high water repellency and being stable against friction. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of water-repellent fine particles contained in a composite plating solution according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an example of a composite plating film formed using the composite plating solution.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water-repellent fine particle 2 Core 3 Water-repellent layer 10 Composite plating film 11 Metal base material layer

Claims (6)

[Claims] 1. A water-repellent fine particle comprising a metal salt and water-repellent fine particles, wherein the water-repellent fine particles have a core and a water-repellent layer covering the surface of the core. A composite plating solution that is formed using a chemical pitch. 2. The composite plating solution according to claim 1, wherein said core has a functional group capable of chemically bonding to said fluoride pitch on said surface. 3. The method according to claim 3, wherein said functional group is at least one selected from the group consisting of an amino group, a hydroxyl group, an alcoholate group, a phenolate group, an alkali metal base of an acid, a mercapto group and an epoxy group. Composite plating solution. 4. The composite plating solution according to claim 2, wherein the functional group is provided on the surface of the core using a surface treatment agent. 5. A method for forming, on a substrate, a composite plating film in which water-repellent fine particles are dispersed in a metal base material layer, comprising: a metal salt for forming the metal base material layer; A step of preparing a composite plating solution comprising a core and a water-repellent layer covering the surface thereof, and the water-repellent layer comprising water-repellent fine particles formed by using fluorinated pitch having surface activity; Dipping the substrate in a composite plating solution and applying a plating method to the substrate. 6. The method for forming a composite plating film according to claim 5, further comprising a step of heat-treating the composite plating film obtained by said plating method.