JP4150935B2 - Surface treatment in the presence of organic solvents - Google Patents

Description

  The present invention relates to electrochemical reactions. More particularly, the present invention relates to an electrochemical reaction efficiency technique by adding an aqueous metal salt solution and a hydrophobic solvent, and a surface treatment technique using the same.

  In electroplating (electrolytic plating), cracks and pinholes are generated on the plating film due to hydrogen generated by electrolysis of the plating solution. Various techniques have been developed to prevent this. Among them, as a promising method, a method of peeling bubbles by lowering the surface tension by using a surfactant has been studied. In particular, fluorine surfactants are considered to have higher functions than other surfactants, and various compounds have been disclosed (Patent Documents 1 and 2).

However, it is difficult to produce a completely pinholeless metal thin film by these methods, and it has usually been avoided by coating as thick as the cost permits. Alternatively, a dry process such as sputtering is employed.
Japanese Patent No. 3334594 Japanese Patent Application Laid-Open No. 64-25995

  It is an object of the present invention to provide a technique for easily realizing a high-quality metal film that reduces metal waste liquid in electrochemical surface treatment and that has good contact and no pinholes.

  It is known that a solvent composed of a perfluoroalkyl compound, a polysiloxane, and an ionic liquid dissolve a large amount of gas in the solvent as compared with a general hydrocarbon solvent.

  Table 1 shows the solubility of oxygen. It can be seen that oxygen is well dissolved in the perfluoro solvent. From this data, removal of hydrogen, which is the cause of pinholes, can be expected by the coexistence of a solvent having high gas solubility such as a fluorine solvent.

  Furthermore, in order to coexist in an electrochemical reaction field such as plating, properties such as chemical stability and incombustibility are required, but it is presumed that a perfluoroalkyl solvent is also suitable in this respect.

  Based on the above, it is presumed that a metal film without pinholes can be formed if the coexisting hydrophobic solvent can dissolve and remove bubbles generated on the substrate during the electrochemical reaction. Furthermore, compared with the metal salt aqueous solution, a general organic solvent has a low surface tension, and particularly a fluorine solvent has a low intermolecular force. Therefore, if an emulsified state can be formed, the surface tension of the entire electrolyte solution is lowered. For this reason, if surface treatment such as plating is performed in an emulsified state formed from a metal salt aqueous solution and a hydrophobic solvent in the presence of a surfactant, it is possible to uniformly treat the inside of the microstructure. .

  Further, since the surfactant solution also has a cleaning effect, it is possible to simplify the steps before and after the surface treatment such as plating, and to reduce waste liquid.

  Furthermore, according to the present method, the amount of the plating solution can be reduced by the amount of the mixed hydrophobic solvent, so that it is possible to reduce the metal waste liquid and the waste liquid treatment cost.

By the way, also in chemical plating other than electroplating, hydrogen gas is generated with the deposition of plating, and pinholes are generated. For this reason, the present invention can contribute to the formation of a pinholeless film even in chemical plating. Based on the above estimation, the present inventors added a hydrophobic solvent with high gas solubility to an aqueous metal salt solution. By carrying out the surface treatment operation in the state of emulsification or turbidity, the inventors have reached the invention shown below.
[1] A surface treatment method comprising subjecting an object to surface treatment in the presence of an aqueous solution containing a metal salt and a hydrophobic solvent.
[2] The method according to [1], wherein the surface treatment is performed by emulsifying an aqueous solution containing a metal salt and a hydrophobic solvent with stirring, and then emulsifying by adding a surfactant. The method according to [1] or [2], wherein surface treatment is performed.
[4] The method according to any one of [1] to [3], wherein the hydrophobic solvent is a fluorine solvent.
[5] The method according to any one of [1] to [3], wherein the hydrophobic solvent is a silicon-based solvent.
[6] The method according to [4] or [5], further comprising adding another organic solvent.
[7] The method according to any one of [1] to [4], [6], wherein the hydrophobic solvent is a fluorine solvent having a perfluoroalkyl group in the molecule.
[8] The method according to any one of [1] to [4], [6], wherein the hydrophobic solvent is a fluorine solvent having a perfluoropolyether group in the molecule.
[9] A metal film obtained by the method according to any one of [1] to [8].
[10] A method for producing an article having a metal film, which comprises subjecting an object to surface treatment in the presence of an aqueous solution containing a metal salt and a hydrophobic solvent.
[11] An article having a metal film obtained by the method of [10].

  According to the surface treatment method of the present invention, a high-grade metal film can be easily formed on an object. Thereby, the article | item which has a high quality metal membrane | film | coat can be manufactured. In addition, the amount of waste liquid such as heavy metals generated during the surface treatment is smaller than that of the existing electrochemical surface treatment.

  Hereinafter, the present invention will be described in detail.

  As the hydrophobic solvent effective in the present invention, an aqueous solution of metal salt and any solvent that can be emulsified can be used. In particular, the solubility of gas (particularly hydrogen) such as fluorine solvent, silicon-based solvent, chlorofluorocarbon, and ionic liquid. A large one is effective. Furthermore, chemical, physical stability, nonflammability, and low toxicity are required for safety during operation. From this point, a fluorine solvent is desirable, and a low-viscosity perfluoropolyether compound having a low vapor pressure is particularly desirable. In practice, a low viscosity is desirable in consideration of the efficiency of stirring. Since the intermolecular force is small, the fluorine solvent has a low viscosity for the molecular weight, and is a desirable solvent from the viewpoint of the stirring efficiency.

  The fluorine solvent is a compound in which some or all of the C—H bonds in the hydrocarbon are replaced with C—F bonds, and examples thereof include a fluorine solvent having a perfluoroalkyl group and a fluorine solvent having a perfluoropolyether group in the molecule.

  Examples of the fluorine-containing solvent having a perfluoroalkyl group are obtained by electrolytic fluorination or cobalt fluorination of heptafluorocyclopentane, octafluorocyclopentene, perfluorohexane, perfluorodecalin, perfluorotripropylamine, perfluorotetrahydrofuran, perfluorodimethylcyclohexane, etc. Can be mentioned.

As the fluorine solvent having a perfluoropolyether group, for example, the general formula F- (CF ₂ O) _o- (C ₃ F ₆ O) _m- (C ₂ F ₄ O) _n- (CF ₂ O) _p- ( CF ₂ ) _q -CF ₃ (where o, p and q are 0 or 1, m and n are not 0 but an integer of 0 to 50 and n + m ≦ 50. Each repeating unit) -(C ₃ F ₆ O) _m- means-(CF ₂ CF ₂ CF ₂ O) _m- or-(CF (CF ₃ ) CF ₂ O) _m -,-(C ₂ F ₄ O) _n — represents a perfluoropolyether compound represented by — (CF ₂ CF ₂ O) _n — or — (CF (CF ₃ ) O) _n —.

Other fluorine solvents having perfluoropolyether groups include the formula: F- (CF ₂ ) _q- (OC ₃ F ₆ ) _m- (OC ₂ F ₄ ) _n- (OCF ₂ ) _o- (CH ₂ ) _p - a compound containing a unit represented by, or the formula _{:-( CH 2) p - (CF} 2 O) o - (C 2 F 4 O) n - (C 3 F 6 O) m - (CF 2) q _{- (OC 3 F 6) m} - (OC 2 F 4) n - (OCF 2) o - (CH 2) p - compounds comprising a unit represented by the like. (Where m and n are 0 to 50 integers that are not 0 at the same time, satisfy n + m ≦ 50, o is an integer from 0 to 20, p is an integer from 0 to 2, and q is from 1 to 10) Regardless of the order of each repeating unit,-(OC ₃ F ₆ ) _m- is-(OCF ₂ CF ₂ CF ₂ ) _m- or-(OCF (CF ₃ ) CF ₂ ) _m- -(OC ₂ F ₄ ) _n -represents-(OCF ₂ CF ₂ ) _n- or-(OCF (CF ₃ )) _n- , respectively.)
The above-mentioned fluorine solvent having a perfluoropolyether group is easily available. For example, demnam (manufactured by Daikin Industries), Krytox (manufactured by DuPont), fomblin (manufactured by Solvay Solexis), Galden (Solve) For example, isolexis). In addition, a fluorine-hydrocarbon hybrid type compound having a fluoroalkyl group mentioned here in the molecule, such as hydrofluoroether (HFE), can also function effectively.

The silicon-based solvent is a compound having a polyalkyl silicon group in the molecule. For example, a polydialkylsiloxane represented by the formula: (R— (Si (R ′) ₂ O) _n —R ″ (wherein R, R ′ and R ″ are the same or different and each represents hydrogen or carbon number) A hydrocarbon group of 1 to 20. n represents an arbitrary positive integer.); A copolymer of the polydialkylsiloxane and another hydrocarbon polymer (which may have various substituents). ); An alkoxyalkylsilane represented by the formula (R—Si (OR ′) ₃ , R ₂ Si (OR ′) ₂ , or R ₃ SiOR ′ (wherein R and R ′ are each hydrogen or C 1-20) It is a hydrocarbon group.

  Fluorocarbons include CFC-113, HCFC-13, HCFC-141b, HCFC-225ca, HCFC-225cb and other HCHF, HFC-365mfc, HFC-c-447ef, HFC-43-10mee, HFC-52-13p And HFCs mentioned above and the like.

The ionic liquids, tetraalkylammonium, tetraalkylphosphonium, have N- alkylpyridinium, 1,3-dialkyl-imidazolium, trialkyl sulfonium as a _{^{cation, BF 4 -, PF 6 -}} , SbF 6 -, NO 3 _{^{-, CF 3 SO 3 -,}} (CF 3 SO 3) 2 N -, ArSO 3 -, CF 3 CO 2 -, CH 3 CO 2 -, Al 2 Cl 7 - organic salts can be exemplified having as an anion.

  The hydrophobic solvent of the present invention broadly includes solvents that are liquid at room temperature (20 to 25 ° C.) and can be separated from water, and the viscosity may be any viscosity that can be stirred at room temperature. In order to facilitate the process, a low-viscosity solvent is particularly preferable. The molecular weight of the hydrophobic solvent is not particularly limited as long as the above conditions are satisfied, but is about 250 to 3000, for example.

  Although there is no major limitation on the composition ratio between the hydrophobic solvent and the metal salt aqueous solution, the surface treatment can be sufficiently performed if the amount of the metal salt aqueous solution is 0.01 wt% or more with respect to the hydrophobic solvent. Therefore, the amount of the hydrophobic solvent with respect to the aqueous metal salt solution can be used at about 1 wt% to 99 wt%, preferably 5 to 95 wt%, more preferably 10 to 90 wt%.

  The metal salt aqueous solution used in the present invention does not need to be specifically adjusted, and a commercially available product such as a plating solution can be used.

  As the metal of the metal salt used in the present invention, Ni, Co, Cu, Zn, Cr, Sn, W, Fe, Ag, Cd, Ga, As, Cr, Se, Mn, In, Sb, Te, Ru, Rh , Pd, Au, Hg, Tl, Pb, Bi, Po, Re, Os, Ir, Pt, and the like. Examples of metal salts include halides such as water-soluble chlorides, bromides, and iodides, and nitrates. And organic acid salts such as sulfate, sulfamate and acetate, cyanide, oxide, hydroxide and complex. The metal salt may be a single metal salt or a combination of two or more metal salts. The concentration of the metal salt can be appropriately selected according to the metal species, but can be set to 0.01 wt% or more in the metal salt aqueous solution, for example, from the viewpoint of obtaining a practical reaction rate.

In the surface treatment method of the present invention, bubbles (for example, in the case of electrolysis or chemical reaction of water such as electroplating, chemical plating, electroforming, anodizing, electropolishing, electrolytic processing, electrophoretic coating, electrolytic refining, and chemical treatment) This is a treatment method that generates hydrogen), and is characterized in that the bubbles are removed by dissolving in a hydrophobic organic solvent to obtain a high-quality film without pinholes. Here, a film having no pinholes refers to a film having 1 or less pinholes having a diameter of 1 μm or more per 1 cm ² . If there are no bubbles, not only will there be no pinholes, but it will also prevent hydrogen embrittlement of the metal film and improve the film strength. Preferred surface treatments are electroplating, chemical plating, anodizing, electroforming, electrolytic polishing, electrolytic processing, electrolytic refining, and electrophoretic coating.

  In the present invention, the addition of a surfactant to emulsify the hydrophobic solvent and the metal salt aqueous solution affects the surface treatment efficiency. Although electroplating is possible without adding a surfactant, it can be made very efficient by adding it. As the surfactant, many conventionally known compounds can be used, and nonionic, anionic, cationic and zwitterionic surfactants, and these constituent elements are also hydrocarbon-based, silicon-based, Fluorine-based materials can be used, and at least one of these can be selected and used. The concentration of the surfactant is not particularly limited, but may be, for example, about 0.0001 to 20 wt%, preferably about 0.001 to 10 wt% with respect to the metal salt aqueous solution.

  Examples of preferable surfactants include fluorine-based surfactants, silicon-based surfactants, and hydrocarbon-based surfactants, and more preferable are fluorine-based surfactants and silicon-based surfactants.

  Specific examples of the surfactant are described below.

  The fluorosurfactant is a surfactant having a polyfluoroalkyl in which at least one of hydrogen atoms of alkyl is substituted with a fluorine atom. For example, polyfluoroalkyl sulfonate, polyfluoroalkyl carboxylate, Anionic compounds such as fluoroalkylbenzene sulfonate, polyfluoroalkyl sulfate, polyfluoroalkyl ether sulfate, polyfluorophenyl ether sulfate, polyfluoroalkyl derivatives of sulfosuccinate; polyfluoropolyalkylene glycol, poly Fluoroalkylolamide, polyfluoro higher alcohol, polyfluoro fatty acid ester, polyfluoropolyether carboxylic acid ester, polyfluoroalkylamine ethylene oxide adduct Nonionic compounds such as polyfluoroalkylcarboxylic acid and polyfluoropolyethercarboxylic acid; cationic compounds such as monopolyfluoroalkylammonium halide, dipolyfluoroalkylammonium halide and tripolyfluoroalkylammonium halide; intramolecular such as polyfluoroalkylbetaine Amphoteric compounds having both cationic anions. Of these, nonionic compounds are preferred. The above polyfluoroalkyl includes perfluoroalkyl in which all of the hydrogen atoms of alkyl are substituted with fluorine atoms.

  Examples of the silicone-based surfactant include polydimethylsiloxanes having a group containing polyalkylene glycol, polyol, ester, amide, amino alcohol, alkyl ammonium, alkyl sulfonate, alkyl carboxyl, alkyl phosphate, and the like. Examples thereof include alkoxyalkylsilicones. Of these, polydimethylsiloxanes or polyalkoxyalkylsilicones having a group containing polyalkylene glycol are preferred.

  Examples of hydrocarbon surfactants include α-olefin sulfonates, alkylbenzene sulfonates, alkyl sulfate esters, alkyl ether sulfate esters, sulfosuccinates, phosphate esters, ether sulfonates, alkylphenols, and higher grades. Alcohol, polyol, polyalkylene glycol, alkylolamide, fatty acid ester, fatty acid amine, alkylamine ethylene oxide adduct, lauryltrimethylammonium salt, stearyltrimethylammonium salt, hexadecylpyridinium salt, imidazolium betaine and the like can be mentioned. Of these, polyalkylene glycol is preferred.

  In the surface treatment, the temperature and pressure are not particularly limited, and it is not always necessary to heat or pressurize. It is possible to carry out in the range of temperature and pressure required for normal surface treatment.

  The temperature of the surface treatment process may be about 0 ° C. to 200 ° C. For example, in the case of electroplating, the plating temperature depends on the metal, and is about room temperature (20 ° C.) to about 100 ° C. For example, the temperature is from room temperature to 80 ° C for nickel and gold, 30 ° C to 70 ° C for palladium, room temperature to 70 ° C for copper, and about 50 ° C to 100 ° C for platinum.

  The pressure in the surface treatment process may be less than 10 atm. In order to avoid an increase in pressure due to vaporization of the solvent at the processing temperature, a high boiling point solvent is used when processing at a high temperature. From the viewpoint of safety, it is desirable to perform surface treatment at 1 to 2 atmospheres by setting such treatment conditions.

  Furthermore, the following organic solvents (cosolvents) can also be added. For example, alcohols such as methanol, ethanol, propanol, butanol and pentanol; ketones such as acetone; acetonitrile; esters such as ethyl acetate; ethers such as ethyl ether; chlorofluorocarbons; halides such as methylene chloride and chloroform In particular, those having low toxicity and low molecular weight are desirable. When an organic solvent is added, the amount added is 50 wt% or less, preferably about 5 to 10 wt%, relative to the hydrophobic solvent.

  In the present invention, since the system is a two-phase system, stirring is required. Here, stirring includes magnetic stirring, mechanical stirring, or mixing by ultrasonic irradiation. The specific number of rotations varies depending on the type of hydrophobic solvent or metal salt aqueous solution, the scale of the apparatus, and the stirring method, and therefore needs to be optimized during actual operation.

  For example, in the case of magnetic stirring or mechanical stirring, 100 to 100000 rpm, preferably 400 to 1000 rpm is exemplified, and in the case of ultrasonic irradiation, 20 kHz to 10 MHz is exemplified.

  The thickness of the metal film formed by the surface treatment of the present invention can be appropriately selected according to the application, plating conditions, etc., and is, for example, about 1 nm to 1000 μm, preferably about 10 nm to 100 μm.

  The material of the surface treatment object is not particularly limited, and examples thereof include metals, alloys, ceramics, plastics, glasses, conductive polymers, etc. In the case of non-conductive materials (for example, plastics), the surface is made of metal. The thing which surface-treated, such as making particles adhere, is illustrated. Examples of the shape of the surface treatment object include a plate shape, a granular shape, a spherical shape, a curved surface shape, a cylindrical shape, and the like, and a shape in which the treatment liquid containing the metal salt aqueous solution and the hydrophobic solvent is sufficiently supplied with stirring. Are preferred.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example, this invention is not limited only to this.

[Example 1] Nickel electrolytic plating In a beaker with an internal volume of 50 cc, nickel plating solution (watt bath: nickel sulfate 280 g / L, nickel chloride 60 g / L, boric acid 50 g / L, appropriate amount of brightener) 20 mL, and Perfluorohexane 20 mL Into the mixture, 0.1 wt% of F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) COOCH ₂ CH ₂ OCH ₃ as a surfactant was added to the plating bath, and the cathode was degreased to the cathode. Pure nickel plates (each with a surface area of 4 cm ² ) were attached. The temperature of this mixture was raised to 50 ° C. in a thermostatic bath. These were emulsified by fixing on a stirrer and rotating the rotor at 500 rpm. Nickel plating was performed by energizing at 5 A / dm ² for 0.5 minutes. After energization, the cathode plate was taken out, sufficiently washed with water, and the surface was observed with a microscope. The film thickness was 0.5 microns. The micrographs are shown in FIGS.

  As is apparent from FIG. 1, no pinhole is detected. Also, as can be seen from the high magnification (5,000 and 50,000 times, respectively) photographs by SEM in FIGS. 2 and 3, a dense film can be formed with very fine crystals. This is probably because the gas generated on the substrate was dissolved and removed in the chlorofluorocarbon solvent.

[Comparative Example 1] Bright Nickel Plating 40 mL of nickel plating solution (watt bath) is placed in a 50 cc beaker similar to that in Example 1, and a brass plate as a cathode and a pure nickel plate as an anode (each surface area from the top of the container). 4cm ² ) was attached. The liquid temperature was set to 50 ° C., and nickel plating was performed by applying current at 5 A / dm ² for 0.5 minutes while stirring with a magnetic stirrer (500 rpm). After the post-treatment similar to that in Example 1, the obtained plating film was observed by SEM. FIG. 4 shows a photomicrograph of normal bright nickel plating (thickness 5 microns).

  From FIG. 4, it was found that in the case of forming a film having a thickness of 5 microns or less by ordinary electroplating, many pinholes are generated.

[Example 2] Nickel electroplating As a surfactant, H (CF ₂ ) ₄ CH ₂ OCOCH ₂ CH (SO ₃ Na) COOCH ₂ (CF is added to a mixture of 30 mL of the same nickel plating solution and 20 mL of perfluorodimethylcyclohexane as in Example 1. ₂ ) 0.04 wt% of ₄ H was added to the plating solution. Nickel plating was performed on the brass plate under the same conditions as in Example 1.

[Example 3] Nickel electroplating As a surfactant, F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) CO (OCH) was added to the same mixture of 30 mL of nickel plating solution and 20 mL of perfluorodimethylcyclohexane as in Example 1. the _{2 CH 2) 7 OCH 3 0.04wt} % added with respect to the plating solution was carried out plating. A nickel film similar to that in Example 1 was formed.

[Example 4] Electroless copper plating (1) Catalyst loading step A portion of a polypropylene reagent bottle lid-disk (diameter 3Φ) is allowed to stand on the bottom of a high-pressure apparatus, and an organic platinum complex (1,1, 5-Cyclooctadiene) dimetylplatinum (II) 16mg was put in, sealed, carbon dioxide was introduced and treated at 30MPa and 120 ° C for 15 hours, then heated to 130 ° C and maintained for 3 hours to activate the catalyst. It was. After decompression, the sample was taken out and washed with water followed by methanol. The activated platinum catalyst supported on the sample surface in black was confirmed.
(2) Plating step The sample is placed in a 50 mL beaker similar to that in Example 1, and 30 mL of copper electroless plating solution (Kokusei Chemical Laboratory Co., Ltd.-C-200LT) and 20 mL of perfluorodimethylcyclohexane are added thereto. Further, 0.6 wt% of F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) COOCH ₂ CH ₂ OCH ₃ as a surfactant was added to the solution. The reaction was stirred at 50 ° C. for 15 minutes. The sample was washed with water and the surface was observed. FIG. 5 shows a photograph of the plating sample.

[Example 5] Electroless copper plating The surface of a 2.5 cm plate (thickness 0.5 mm) sample made of the same material as in Example 4 was washed with acetone, dried, and then treated with chromic acid-sulfuric acid solution at 60 ° C for 15 minutes. Treated to roughen the surface. This was immersed in a 0.5 mM-PdCl ₂ -0.05 mM-SnCl ₂ solution for 30 minutes. After washing with water, the sample was allowed to stand in a 50 mL beaker similar to that in Example 1, and 30 mL of copper electroless plating solution (Kokusei Chemical Laboratory Co., Ltd.-C-200LT) and 20 mL of perfluorodimethylcyclohexane were further added. To the solution, 0.6 wt% of F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) COOCH ₂ CH ₂ OCH ₃ as a surfactant was added to the plating solution. The reaction was stirred at 50 ° C. for 15 minutes. The sample was washed with water and the surface was observed. FIG. 6 shows a photograph of the plating sample.

[Example 6] Electrolytic palladium plating Palladium plating bath (10 g / L of palladium chloride in an aqueous solution of ethylenediamine 10 g / L was added to a beaker having an internal volume of 50 cc and heated at 60 ° C. to prepare a uniform solution. 2N hydrochloric acid was added to adjust the pH to 3.) 30 mL and 20 mL of perfluorodimethylcyclohexane were added, and F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) was added as a surfactant to this solution. CO (OCH ₂ CH ₂ ) ₂ OCH ₃ was added at 0.6 wt% with respect to the plating solution. A degreased brass plate was attached to the cathode and a titanium plate (surface area 4 cm ² each) was attached to the anode. The temperature of this mixture was raised to 60 ° C. in a thermostatic bath. These were emulsified by fixing on a stirrer and rotating the rotor at 500 rpm. Current was applied at ^{2 A} / dm ² for 0.5 minutes to perform nickel plating. After energization, the cathode plate was taken out, sufficiently washed with water, and the surface was observed with a microscope. The SEM photograph was shown to FIGS. A very dense film with fine crystal grains and no pinholes is formed. Also, it can be traced into the groove of the Hull cell substrate, and the attachment is very good.

Example 7 Electrolytic Palladium Plating The same palladium plating as in Example 6 was performed using an alkaline bath (Nippon Electroplating Engineers, Paradex LF-2) as the plating solution. The obtained plating film was slightly less uniform than Example 6. A better trend was observed in the acidic bath.

[Example 8] Electrolytic copper plating 30 mL of High Purity Chemical Laboratory Co., Ltd.-C-100ES was used as the copper plating solution, 20 mL of perfluorodimethylcyclohexane was added, and F (CF (CF ₃ CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) CO (OCH ₂ CH ₂ ) ₂ OCH ₃ was added at 0.6 wt% with respect to the plating solution. A brass plate was attached to the cathode, and a titanium plate (surface area of 4 cm ² ) was attached to the anode, emulsified with stirring, and then energized at 50 ° C. and 2 A / dm ² for 0.5 minutes to perform copper plating. FIG. 10 shows an SEM photograph. A uniform film without pinholes is obtained.

[Example 9] Electrolytic gold plating Using 30 mL of acidic gold plating solution (High Purity Chemical Laboratory-Pure Gold Electroplating Solution K-24EA10), 20 mL of perfluorodimethylcyclohexane was added, and F was added as a surfactant to this solution. (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) COOCH ₂ CH ₂ OCH ₃ was added at 0.6 wt% with respect to the plating solution. A brass plate was attached to the cathode of the plating tank and a titanium-coated titanium plate (surface area of 4 cm ² each) was immersed in the plating solution while energizing, and the lid was closed. Stirring was started to emulsify the plating solution-perfluoro solvent, and then energization was carried out at 0.5 A / dm ² at 50 ° C. for 170 seconds (voltage during energization: about 3 V) to perform gold plating (film thickness: 0.7 μm). ). SEM photographs are shown in FIGS. A uniform film without pinholes was obtained.

[Example 10] Electrolytic gold plating F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF as a surfactant was added to a mixed solution of 30 mL of gold plating solution and 20 mL of fluorinate (FC-77) as in Example 9. ₃ ) 10 mg of COOH was added and the same operation as in Example 9 was performed.

[Example 11]
As in Example 1, as a surfactant, a mixture of 30 mL of nickel plating solution and 20 mL of CF ₃ [(OCF (CF ₃ ) CF ₂ ) _x (OCF ₂ ) _y ] OCF ₃ (oligomer mixture, boiling point = 135 ° C.) 20 mg of F (CF (CF ₃ ) CF ₂ O) ₃ CF (CF ₃ ) COOCH ₂ CH ₂ OCH ₃ was added, and the mixture was energized at 50 ° C. and a current density of 5 A / dm ² for 3 minutes to carry out nickel plating.

As described in the above embodiments, according to the present invention, even a very thin thin film can be formed with 1 or less pinholes having a diameter of 1 μm or more per 1 cm ² .

The SEM photograph (500-times multiplication factor) which shows the plating film obtained in Example 1 is shown. The SEM photograph (magnification 5000 times) which shows the plating film obtained in Example 1 is shown. The SEM photograph (magnification 50000 times) which shows the plating film obtained in Example 1 is shown. The SEM photograph (magnification 500 times) of normal bright nickel plating (thickness 5 microns) obtained in Comparative Example 1 is shown. The photograph of the sample obtained in Example 4 is shown. The photograph of the sample obtained in Example 5 is shown. The SEM photograph (60-times multiplication factor) which shows the plating film obtained in Example 6 is shown. The SEM photograph (1000-times multiplication factor) which shows the plating film obtained in Example 6 is shown. The SEM photograph (10000-times multiplication factor) which shows the plating film obtained in Example 6 is shown. The SEM photograph (1000-times multiplication factor) which shows the plating film obtained in Example 8 is shown. The SEM photograph (110-times multiplication factor) which shows the plating film obtained in Example 9 is shown. The SEM photograph (1000-times multiplication factor) which shows the plating film obtained in Example 9 is shown. The SEM photograph (magnification 20000 times) which shows the plating film obtained in Example 9 is shown.

Claims (11)

A method of subjecting an object to surface treatment in the presence of an aqueous solution containing a metal salt and a hydrophobic solvent , wherein the hydrophobic solvent is a silicon solvent or an ionic liquid, and an aqueous solution containing the metal salt under stirring A surface treatment method comprising emulsifying a hydrophobic solvent to perform surface treatment. A method of subjecting an object to surface treatment in the presence of an aqueous solution containing a metal salt and a hydrophobic solvent, wherein the hydrophobic solvent is a fluorinated solvent or fluorocarbon that is liquid at room temperature, and the metal salt is contained under stirring. A surface treatment method comprising emulsifying an aqueous solution and a hydrophobic solvent and performing a surface treatment under a pressure of less than 10 atm. The method according to claim 2 , wherein the surface treatment is performed under a pressure of 1 to 2 atmospheres . Furthermore, surfactant is added and emulsified and surface treatment is performed, The method in any one of Claims 1-3 characterized by the above-mentioned. Furthermore, another organic solvent is added, The method in any one of Claims 1-4 characterized by the above-mentioned. The method according to claim 2 , wherein the hydrophobic solvent is a fluorine solvent having a perfluoroalkyl group in the molecule. The method according to claim 2 , wherein the hydrophobic solvent is a fluorine solvent having a perfluoropolyether group in the molecule. Pinholes 1 cm ² per the following metals coating of obtained by the method, the diameter is more than 1μm according to any one of claims 1-7. A method for producing an article having a metal film, wherein an object is surface-treated in the presence of an aqueous solution containing a metal salt and a hydrophobic solvent composed of a silicon-based solvent or an ionic liquid, and the metal salt is added under stirring. A production method comprising emulsifying an aqueous solution containing a hydrophobic solvent and performing a surface treatment. A method for producing an article having a metal film, wherein an object is surface-treated in the presence of an aqueous solution containing a metal salt and a hydrophobic solvent composed of a fluorine solvent or a fluorocarbon that is liquid at room temperature, and the metal is stirred under stirring. A production method comprising emulsifying an aqueous solution containing a salt and a hydrophobic solvent, and performing a surface treatment under a pressure of less than 10 atm . An article obtained by the method according to claim 9 or 10, wherein the pinhole having a diameter of 1 µm or more has a metal film of 1 or less per 1 cm ² .

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