WO2012133613A1 - Trivalent chromium plating solution - Google Patents

Trivalent chromium plating solution Download PDF

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Publication number
WO2012133613A1
WO2012133613A1 PCT/JP2012/058300 JP2012058300W WO2012133613A1 WO 2012133613 A1 WO2012133613 A1 WO 2012133613A1 JP 2012058300 W JP2012058300 W JP 2012058300W WO 2012133613 A1 WO2012133613 A1 WO 2012133613A1
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Prior art keywords
plating solution
trivalent chromium
compound
chromium plating
plating
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PCT/JP2012/058300
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French (fr)
Japanese (ja)
Inventor
學 品田
鈴木　正行
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日本化学工業株式会社
株式会社クリタ
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Application filed by 日本化学工業株式会社, 株式会社クリタ filed Critical 日本化学工業株式会社
Priority to JP2013507708A priority Critical patent/JP5890394B2/en
Publication of WO2012133613A1 publication Critical patent/WO2012133613A1/en

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/04—Electroplating: Baths therefor from solutions of chromium
    • C25D3/06—Electroplating: Baths therefor from solutions of chromium from solutions of trivalent chromium
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D15/00—Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
    • C25D15/02—Combined electrolytic and electrophoretic processes with charged materials
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C25D5/50—After-treatment of electroplated surfaces by heat-treatment

Definitions

  • the present invention relates to a chromium plating solution containing trivalent chromium.
  • Chrome plating is widely used as decorative plating because it does not corrode in the atmosphere and does not lose its luster. In addition, since it has a high hardness and a low coefficient of friction, it is widely used for machine parts that require wear resistance. However, a large amount of hexavalent chromium is used in the plating solution used for this plating. Since hexavalent chromium is concerned about the influence on the human body, development of a plating solution using trivalent chromium with little concern is desired.
  • Patent Document 1 describes using a plating solution having a composition of chromium chloride hexahydrate, boric acid, glycine, ammonium chloride, and aluminum chloride hexahydrate. ing.
  • This plating solution has an advantage that a good plating surface can be obtained.
  • ammonium chloride in the plating solution may be decomposed to generate chlorine gas, there is a concern that the working environment may be adversely affected.
  • Patent Document 2 describes that ammonium sulfamate is used as an ammonium source in order to deposit a thick chromium plating having a specular gloss.
  • Patent Document 3 proposes adding urea to a trivalent chromium-containing liquid for the purpose of maintaining the water resistance of the chemical conversion treatment film with trivalent chromium.
  • the present invention provides a trivalent chromium plating solution comprising an aqueous solution containing a trivalent chromium compound, a pH buffer, an aminocarboxylic acid compound, a sulfamate compound and an aminocarbonyl compound.
  • a trivalent chromium plating solution having an industrially satisfactory film thickness and capable of forming a chromium plating excellent in film properties such as corrosion resistance and wear resistance. Further, according to the present invention, since generation of harmful gas such as halogen gas due to decomposition of components in the liquid can be suppressed, a trivalent chromium plating solution that is excellent in long-term storage and leads to improvement of the working environment is provided.
  • the trivalent chromium plating solution of the present invention uses water as a medium.
  • This plating solution contains a trivalent chromium compound, a pH buffer, an aminocarboxylic acid compound, a sulfamate compound, and an aminocarbonyl compound.
  • a water-soluble compound having a trivalent chromium valence can be used without particular limitation.
  • examples of such compounds include inorganic acid chromium such as chromium chloride, chromium nitrate, chromium sulfate and chromium phosphate, chromium lactate, chromium gluconate, chromium glycolate, chromium oxalate, chromium malate, chromium maleate, and malon.
  • Organic acid chromium such as chromium acid chromium, chromium citrate, chromium acetate and chromium tartrate can be mentioned.
  • trivalent chromium compounds can be used alone or in combination of two or more.
  • concentration of trivalent chromium in the plating solution is preferably 0.2 to 1.4 mol / liter, more preferably 0.4 to 1.2 mol / liter, from the viewpoint that chromium plating can be performed successfully.
  • the pH buffer contained in the plating solution is blended for the purpose of successfully carrying out chrome plating by making the pH suitable for chrome plating.
  • Suitable pH buffering agents for this purpose include, for example, boric acid, sodium borate, potassium borate, ammonium sulfate, phosphoric acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium carbonate, and sodium bicarbonate. . It is particularly preferable to use boric acid, sodium borate or potassium borate. These compounds can be used alone, or can be used as a buffer system combining two or more kinds.
  • the blending amount of the pH buffering agent may be an amount that can maintain the pH of the plating solution preferably at 0.5 to 2.0, more preferably at 0.8 to 1.5.
  • boric acid is used as a pH buffer, in addition to the pH buffer action, there is an advantage that the metal chromium crystals produced by reduction are refined.
  • the aminocarboxylic acid compound contained in the plating solution is blended for the purpose of forming a complex with trivalent chromium in the plating solution to stabilize the plating solution and to successfully perform chromium plating.
  • An aminocarboxylic acid compound is a compound having at least one amino group and at least one carboxyl group in the molecule. Examples of the aminocarboxylic acid compound include glycine, alanine, aspartic acid, glutamic acid, and arginine. In particular, glycine or alanine is preferably used. These compounds can be used alone or in combination of two or more.
  • the aminocarboxylic acid compound When the aminocarboxylic acid compound is blended in an amount of 0.3 to 2 mol, particularly 0.5 to 1.7 mol, with respect to 1 mol of trivalent chromium in the plating solution, a stable plating solution of a chromium complex is obtained. This is preferable because proper electrolytic plating can be performed.
  • the concentration of the aminocarboxylic acid compound in the plating solution is preferably 0.4 to 1.7 mol / liter, particularly 0.5 to 0.9 mol / liter.
  • the sulfamate compound contained in the plating solution mainly has a role as a supporting electrolyte in the plating solution, and is blended for the purpose of increasing the electrical conductivity of the plating solution to a predetermined level. Further, since the sulfamate compound also has a pH buffering action of the plating solution, the pH of the plating solution is further stabilized by the combined use with the pH buffer described above. Further, the sulfamate compound also has a catalytic action when trivalent chromium is reduced, thereby exhibiting the effect of refining metal chromium crystals and the effect of glossing the chromium film.
  • sulfamate for example, ammonium sulfamate, sodium sulfamate, or potassium sulfamate can be used. These compounds can be used alone or in combination of two or more.
  • the sulfamate is preferably added in an amount of 0.3 to 2.5 mol, particularly 0.5 to 2 mol, with respect to 1 mol of trivalent chromium in the plating solution.
  • the concentration of sulfamate in the plating solution is preferably 0.4 to 2.1 mol / liter, particularly 0.8 to 1.9 mol / liter.
  • the aminocarbonyl compound contained in the plating solution is a compound having at least one carbonyl group and at least one amino group in the molecule.
  • the aminocarbonyl compound has the effect of increasing the reduction rate of trivalent chromium.
  • the reason is considered as follows. That is, in the process where trivalent chromium is reduced to metallic chromium, divalent chromium is generated. It is considered that divalent chromium is present adsorbed on the cathode or in the electric double layer.
  • the reduction of trivalent chromium to metallic chromium is the rate-limiting step.
  • the aminocarbonyl compound has a function of increasing the rate at which divalent chromium is reduced to metallic chromium.
  • the present inventor believes that the rate at which trivalent chromium is reduced to metallic chromium is increased.
  • the aminocarbonyl compound has an action of suppressing the triation of trivalent chromium.
  • trivalent chromium is reduced to metallic chromium
  • hydrolysis and olation reactions occur near the cathode, which may inhibit metal chromium electrodeposition.
  • an aminocarbonyl compound is present in the plating solution, the compound forms a complex with trivalent chromium. Since this complex formation reaction is a competitive reaction with the trivalent chromium olation, the trivalent chromium olation can be minimized. This also increases the reduction rate of trivalent chromium.
  • the aminocarbonyl compound serves as a pH buffer that hardens the plating film by supplying nitrogen atoms contained in the compound to the plating film and maintains the pH of the plating solution. It also has an effect.
  • aminocarbonyl compounds have a remarkable effect when used in combination with the sulfamate compounds described above. Details are as follows.
  • the advantages of blending the sulfamate compound in the plating solution of the present invention are as fulfilled, but the electrodeposition stress of the plating film tends to increase due to the use of the sulfamate compound.
  • An increase in electrodeposition stress causes cracks in the plating film.
  • the sulfamate compound and the aminocarbonyl compound coexist, the growth rate of the chromium crystal is increased by the aminocarbonyl compound, so that the development of the magnetic field is inhibited, and as a result, the electrodeposition stress decreases. This effectively suppresses the occurrence of cracks in the plating film.
  • the blending amount of the sulfamate with respect to the aminocarbonyl compound used in the present invention is preferably in the range of 0.4 to 1.5 in terms of molar ratio.
  • aminocarbonyl compounds examples include urea and carbamic acid. These compounds can be used alone or in combination.
  • urea is preferably used because hydrogen at the ⁇ -position with respect to the carbonyl group has high acidity, and thus hydrogen can be easily extracted.
  • the aminocarbonyl compound is blended in an amount of 0.5 to 3.0 mol, particularly 1.1 to 2.2 mol with respect to 1 mol of trivalent chromium in the plating solution. It is preferable from the viewpoints of stabilization, suppression of the formation of chromium hydroxide affecting the properties of the plating film, and promotion of the dense crystallization action of the film.
  • the concentration of the aminocarbonyl compound in the plating solution is preferably 0.5 to 4.4 mol / liter, particularly 0.8 to 2.5 mol / liter.
  • Patent Document 3 described above also describes that urea, which is a kind of aminocarbonyl compound, is added to a trivalent chromium plating solution.
  • urea which is a kind of aminocarbonyl compound
  • the reason for using urea in the same document is to decompose urea to generate ammonia, and to improve the water resistance of the plating film with ammonia ([0033] of Patent Document 3). Therefore, urea itself does not exist in the plating solution described in this document, or even if it exists, the amount thereof is considered to be very small.
  • this document relates to a chromate chemical conversion treatment solution, and the role of urea is completely different from the present invention relating to a plating solution.
  • the rate at which trivalent chromium is reduced to metallic chromium is increased, so that a plating film having an industrially satisfactory film thickness can be easily formed. it can.
  • advantageous effects such as an increase in the hardness of the plating film and an increase in corrosion resistance, wear resistance and the like are also exhibited.
  • ammonium chloride which is a component mixed in the conventional plating solution
  • the plating solution of the present invention generation of chlorine gas generated due to decomposition of ammonium chloride is prevented. This improves the plating work environment.
  • the plating solution of the present invention preferably does not contain ammonium halide such as ammonium chloride.
  • ceramic particles can also be blended in the plating solution of the present invention. Ceramic particles are taken into the plating film during the metal chromium electrodeposition process. Ceramic particles are mainly present at grain boundaries and defects, thereby suppressing the propagation of cracks and effectively mitigating fatigue, breakage, and delamination. In addition, the ceramic particles exposed on the surface contact the mating sliding surface as a sliding surface in the friction and wear action with the mating sliding surface, which helps improve wear and seizure resistance and form an oil film. .
  • the ceramic particles preferably have an average particle size of 0.2 to 12 ⁇ m, particularly 0.4 to 6.0 ⁇ m, particularly 0.5 to 3.0 ⁇ m. The average particle size of the ceramic particles is measured by a laser method particle size distribution analyzer (MICROTRAC MT3000II manufactured by Nikkiso Co., Ltd.).
  • the average particle size of the ceramic particles blended in the plating solution of the present invention is within the above range, the average particle size of the ceramic particles taken into the plating film is preferably 0.2 to 8.0 ⁇ m, more preferably Is 0.3 to 5.0 ⁇ m, particularly preferably 0.5 to 3.0 ⁇ m, and the effects such as fatigue, breakage, and exfoliation are alleviated as described above.
  • the average particle diameter of the ceramic particles in the plating film is measured by a laser microscope (OLS1100 manufactured by OLYMPUS).
  • the shape of the ceramic particles is preferably a spherical shape from the viewpoint of improving the friction with the mating sliding surface and the wear action.
  • the ceramic particles are not particularly limited as long as they do not adversely affect the reduction of trivalent chromium. From the viewpoint of easy incorporation into the plating film, it is preferable to use a zeta potential of 20 to 100 mV, particularly 40 to 70 mV. Examples of such ceramic particles include Al 2 O 3 , Si 3 N 4 , AlN, Cr 3 C 2 , B 4 C, TiC, WC, TiO 2 , Cr 2 O 3 , CBN, and Fe 3 O 4. Can be mentioned. These ceramic particles can be used alone or in combination of two or more. The zeta potential of the ceramic particles is measured by, for example, Zetasizer Nano Series (Malvern Instruments Ltd.).
  • the ceramic particles are blended in the plating solution of the present invention so as to be 10 to 100 g / liter, particularly 20 to 60 g / liter, because the fluidity of the plating solution is suitable. This is preferable from the viewpoint of obtaining an appropriate amount of particles.
  • Ceramic particles generally have a large specific gravity, so they may easily settle in the plating solution. Depending on the particle size, ceramic particles may aggregate in the plating solution. From the viewpoint of preventing these problems, when the ceramic particles are blended in the plating solution, it is preferable to blend aluminum chloride as an aggregation inhibitor together with the ceramic particles. Moreover, it is also preferable to mix
  • Surfactants include anionic surfactants such as monoalkyl sulfates and alkylpolyoxyethylene sulfates, cationic surfactants such as alkyltrimethylammonium salts and dialkyldimethylammonium salts, polyoxyethylene alkyl ethers and fatty acid sorbitans. Nonionic surfactants such as esters are exemplified.
  • aluminum chloride exhibits an advantageous effect of controlling the zeta potential of the ceramic particles to improve the dispersibility of the particles and preventing the particles from aggregating. Moreover, it becomes easy to take in ceramic particles uniformly in a plating film. From the viewpoint of making these effects even more prominent, 0.005 to 0.5 mol, particularly 0.01 to 0.3 mol, of aluminum chloride is added to 1 mol of trivalent chromium in the plating solution. Is preferred. For the same reason, the concentration of aluminum chloride in the plating solution is preferably 0.02 to 0.5 mol / liter, particularly 0.05 to 0.3 mol / liter.
  • a water-soluble organic solvent can be added to the plating solution of the present invention.
  • By blending the water-soluble organic solvent it is possible to effectively prevent plating plating.
  • grains mentioned previously are mix
  • the water-soluble organic solvent is preferably blended in an amount of 0.4 to 2.1 mol, particularly 0.6 to 1.3 mol, with respect to 1 mol of trivalent chromium in the plating solution.
  • the water-soluble organic solvent include glycerin, polyethylene glycol, ethanol, methanol, and n-propanol.
  • the plating solution of the present invention contains a pH buffer as described above, and the pH of the solution is preferably kept in the range of 0.5 to 2.0, more preferably 0.8 to 1.5. .
  • Examples of water that serves as a medium for the plating solution of the present invention include pure water, ion exchange water, industrial water, tap water, and distilled water. Among these, it is preferable to use industrial water and tap water from the economical aspect on the premise that the storage stability of the plating solution and the film properties are not affected.
  • the plating solution of the present invention can contain self-lubricating particles, sulfonic acid group-containing compounds or salts thereof as necessary.
  • the wear resistance of the plating film can be further improved.
  • the self-lubricating particles include graphite, molybdenum disulfide, tungsten disulfide, fluororesin, and boron nitride.
  • the self-lubricating particles are 5 to 70 g / liter, particularly 10 to 50 g / liter, in the plating solution.
  • the sulfonic acid group-containing compound or a salt thereof has an action of increasing the microcrack density of the film, and can impart excellent corrosion resistance.
  • sulfonic acid and disulfonic acid and salts thereof are preferable.
  • Specific examples of the sulfonic acid and disulfonic acid include aliphatic sulfonic acid (eg, methanesulfonic acid, ethanesulfonic acid, etc.), aliphatic disulfonic acid (eg, methanedisulfonic acid, ethanedisulfonic acid, etc.), aromatic sulfonic acid (eg, benzenesulfone, etc.).
  • the concentration of the sulfonic acid group-containing compound or salt thereof is preferably 0.02 to 0.1 mol / L, more preferably 0.04 to 0.07 mol / L, based on the sulfonic acid group.
  • the temperature of the plating bath is preferably set to 30 to 60 ° C., more preferably 40 to 60 ° C.
  • the current density is preferably set to 15 to 60 A / dm 2 , more preferably 20 to 40 A / dm 2 .
  • the anode graphite or various dimensionally stabilized anodes (DSA) such as a Ti—Pt electrode can be used, and as the cathode, an object to be plated can be used.
  • chromium is generally amorphous. Amorphous chromium plating films tend to have lower hardness than crystalline ones. Therefore, the plating film formed by electrolytic plating can be crystallized by heat treatment to form a crystalline chromium film.
  • the conditions for the heat treatment are preferably 150 to 600 ° C., preferably 200 to 600 ° C., more preferably 200 to 450 ° C. in the atmosphere.
  • the heating time is preferably 30 to 60 minutes, provided that the temperature is within this range.
  • the plating film obtained by electrolytic plating under the above conditions has an industrially satisfactory film thickness.
  • the film thickness is preferably 3 to 300 ⁇ m, more preferably 5 to 100 ⁇ m.
  • the plating film obtained by electrolytic plating under the above-described conditions is excellent in film properties such as wear resistance and corrosion resistance. Therefore, by using the trivalent chromium plating solution of the present invention and plating various members, particularly sliding members such as piston rings, rolls, shock absorbers, and the like, the necessary characteristics are imparted to these members. Can do.
  • Examples 1 to 3 and Comparative Examples 1 and 2 The components shown in Table 1 below were added to water to prepare a trivalent chromium plating solution having the composition shown in the same table. Using the obtained plating solution, electrolytic plating was performed under the conditions shown in the same table. A high density graphite plate was used as the anode. An S45C polished steel plate was used as the cathode.
  • the thickness of the chromium plating film in the obtained plated product was measured by the following method. Further, the appearance of the surface of the plating film was visually observed to evaluate the degree of gloss and the presence or absence of cracks. Further, the Vickers hardness of the plating film was measured by the following method, and the wear resistance and corrosion resistance were evaluated by the following methods. Further, for Examples 2 and 3 and Comparative Example 2, the degree of dispersion of the ceramic particles in the plating film was evaluated by the following method. The results are shown in Table 1 below.
  • the cross section of the plating film was measured at a magnification of 400 times using a laser microscope (LEXTO OLS1100 manufactured by OLYMPUS).
  • the wear resistance of the plating film was evaluated using a Kaken type corrosion wear tester.
  • Cast iron FC250 conforming to JIS G 5501-1995
  • the contact load in the friction tester was 39N.
  • the temperature of the corrosive liquid was normal temperature.
  • the amount of wear of the plating film was measured, and the value was used as an index of wear resistance.
  • the dispersity referred to here is the area ratio of ceramic particles in the observation field per unit area when the cross section of the plating film is observed. This area ratio is measured by the following method. That is, the longitudinal section of the plating film is observed at a magnification of 1000 times using a laser microscope (LEXTO OLS1100 manufactured by OLYMPUS). And the ratio of the area which the ceramic particle which exists in a 30 micrometer square frame occupies is process-measured using the laser microscope.
  • Example 1 and Examples 2 and 3 it can be seen that the wear resistance of the plating film is further improved by mixing ceramic particles in the plating solution.
  • the plating solutions containing ceramic particles are compared, in Examples 2 and 3 and Comparative Example 2, the plating solutions of Examples 2 and 3 have higher wear resistance of the plating film. I understand. The reason for this is considered to be that in Examples 2 and 3, both the sulfamate compound and the aminocarbonyl compound are blended in the plating solution.
  • Example 4 The plated product obtained in Example 3 was heat-treated at 400 ° C. for 1 hour in the atmosphere.
  • Vickers hardness was measured in the same manner as in Examples 1 to 3, it was 1550, and it was confirmed that a plating film having a higher hardness than that before the heat treatment was formed.
  • a trivalent chromium plating solution having an industrially satisfactory film thickness and capable of forming a chromium plating excellent in film properties such as corrosion resistance and wear resistance. Further, according to the present invention, since generation of harmful gas such as halogen gas due to decomposition of components in the liquid can be suppressed, a trivalent chromium plating solution that is excellent in long-term storage and leads to improvement of the working environment is provided.

Abstract

The present invention provides a trivalent chromium plating solution that has industrially satisfactory thickness and that is capable of forming chromium plating with excellent corrosion resistance, abrasion resistance, and other film properties. This trivalent chromium plating solution includes a trivalent chromium compound, a pH buffer, an amino carboxylic acid compound, a sulfamic acid salt compound, and an aminocarbonyl compound. The plating solution preferably furthermore includes ceramic particles. A ceramic particle dispersing agent is also preferably included.

Description

三価クロムめっき液Trivalent chromium plating solution
　本発明は、三価のクロムを含有するクロムめっき液に関する。 The present invention relates to a chromium plating solution containing trivalent chromium.
　クロムめっきは、大気中で腐食せず光沢を失わないので、装飾めっきとして広く用いられている。また高い硬度と低い摩擦係数を有するので、耐摩耗性を要する機械部品等に広く用いられている。しかしこのめっきに用いられるめっき液には多量の六価クロムが用いられている。六価クロムは人体への影響が懸念されるので、その懸念の少ない三価クロムを用いためっき液の開発が望まれている。 Chrome plating is widely used as decorative plating because it does not corrode in the atmosphere and does not lose its luster. In addition, since it has a high hardness and a low coefficient of friction, it is widely used for machine parts that require wear resistance. However, a large amount of hexavalent chromium is used in the plating solution used for this plating. Since hexavalent chromium is concerned about the influence on the human body, development of a plating solution using trivalent chromium with little concern is desired.
　三価のクロムを用いためっき液として、例えば特許文献１には、塩化クロム六水和物、ホウ酸、グリシン、塩化アンモニウム及び塩化アルミニウム六水和物の組成のめっき液を用いることが記載されている。このめっき液は、良好なめっき表面を得ることができるという利点を有する。しかし、めっき液中の塩化アンモニウムが分解して塩素ガスが発生する可能性があるので、作業環境に悪影響を及ぼすことが懸念されている。 As a plating solution using trivalent chromium, for example, Patent Document 1 describes using a plating solution having a composition of chromium chloride hexahydrate, boric acid, glycine, ammonium chloride, and aluminum chloride hexahydrate. ing. This plating solution has an advantage that a good plating surface can be obtained. However, since ammonium chloride in the plating solution may be decomposed to generate chlorine gas, there is a concern that the working environment may be adversely affected.
　また、三価のクロムを用いて形成されためっき皮膜は、膜厚を大きくすることが容易でなく、厚いめっき皮膜が要求される工業用途では実用的なめっき液を供給できているとは言い難い。これを解決する目的で、特許文献２では、鏡面光沢を有する厚いクロムめっきを電析させるために、アンモニウム源としてスルファミン酸アンモニウムを使用することが記載されている。 Moreover, it is not easy to increase the film thickness of a plating film formed using trivalent chromium, and it can be said that a practical plating solution can be supplied in industrial applications where a thick plating film is required. hard. In order to solve this, Patent Document 2 describes that ammonium sulfamate is used as an ammonium source in order to deposit a thick chromium plating having a specular gloss.
　特許文献３では三価クロムによる化成処理皮膜の耐水性を維持させる目的で、三価のクロムの含有液に尿素を加えることが提案されている。 Patent Document 3 proposes adding urea to a trivalent chromium-containing liquid for the purpose of maintaining the water resistance of the chemical conversion treatment film with trivalent chromium.
　更に特許文献４では、外観や析出状態を改善するために三価クロムめっき浴中に添加されている硫黄含有化合物の硫黄分が、クロムめっき皮膜中に析出することを抑制することを目的として、該めっき浴中にアミノカルボン酸類を添加することが提案されている。 Furthermore, in patent document 4, in order to suppress the sulfur content of the sulfur-containing compound added in the trivalent chromium plating bath in order to improve the appearance and the precipitation state, the precipitation in the chromium plating film is suppressed. It has been proposed to add aminocarboxylic acids to the plating bath.
国際公開第２００８／１３６２２３号パンフレットInternational Publication No. 2008/136223 Pamphlet 特開平９－９５７９３号公報JP-A-9-95793 特開平６－１７３０２７号公報JP-A-6-173027 特開２０１０－１８９６７３号公報JP 2010-189673 A
　このように、皮膜特性の向上及び作業環境の改善を求めて、三価クロムめっき液について多くの提案がなされているが、さらなる改良が求められている。 As described above, many proposals have been made for trivalent chromium plating solutions in order to improve the film characteristics and the working environment, but further improvements are required.
　本発明は、三価クロム化合物、ｐＨ緩衝剤、アミノカルボン酸化合物、スルファミン酸塩化合物及びアミノカルボニル化合物を含有する水溶液からなる三価クロムめっき液を提供するものである。 The present invention provides a trivalent chromium plating solution comprising an aqueous solution containing a trivalent chromium compound, a pH buffer, an aminocarboxylic acid compound, a sulfamate compound and an aminocarbonyl compound.
　本発明によれば、工業的に満足し得る膜厚をもち、耐食性及び耐摩耗性等の皮膜特性に優れたクロムめっきを形成することのできる三価クロムめっき液が提供される。また、本発明によれば、液中成分の分解によるハロゲンガス等の有害ガスの発生が抑えられるため、長期保存性に優れ、作業環境の改善につながる三価クロムめっき液が提供される。 According to the present invention, there is provided a trivalent chromium plating solution having an industrially satisfactory film thickness and capable of forming a chromium plating excellent in film properties such as corrosion resistance and wear resistance. Further, according to the present invention, since generation of harmful gas such as halogen gas due to decomposition of components in the liquid can be suppressed, a trivalent chromium plating solution that is excellent in long-term storage and leads to improvement of the working environment is provided.
　本発明の三価クロムめっき液は水を媒体とするものである。このめっき液には、三価クロム化合物、ｐＨ緩衝剤、アミノカルボン酸化合物、スルファミン酸塩化合物及びアミノカルボニル化合物が含有されている。 The trivalent chromium plating solution of the present invention uses water as a medium. This plating solution contains a trivalent chromium compound, a pH buffer, an aminocarboxylic acid compound, a sulfamate compound, and an aminocarbonyl compound.
　めっき液に含まれる三価クロム化合物としては、クロムの価数が三価である水溶性化合物を特に制限なく用いることができる。そのような化合物としては、例えば塩化クロム、硝酸クロム、硫酸クロム及びリン酸クロムなどの無機酸クロム、乳酸クロム、グルコン酸クロム、グリコール酸クロム、シュウ酸クロム、リンゴ酸クロム、マレイン酸クロム、マロン酸クロム、クエン酸クロム、酢酸クロム及び酒石酸クロムなどの有機酸クロムが挙げられる。これらの三価クロム化合物は、１種又は２種以上を組み合わせて用いることができる。めっき液中における三価のクロムの濃度は、クロムめっきを首尾よく行い得る点から、好ましくは０．２～１．４ｍｏｌ／リットル、更に好ましくは０．４～１．２ｍｏｌ／リットルとする。 As the trivalent chromium compound contained in the plating solution, a water-soluble compound having a trivalent chromium valence can be used without particular limitation. Examples of such compounds include inorganic acid chromium such as chromium chloride, chromium nitrate, chromium sulfate and chromium phosphate, chromium lactate, chromium gluconate, chromium glycolate, chromium oxalate, chromium malate, chromium maleate, and malon. Organic acid chromium such as chromium acid chromium, chromium citrate, chromium acetate and chromium tartrate can be mentioned. These trivalent chromium compounds can be used alone or in combination of two or more. The concentration of trivalent chromium in the plating solution is preferably 0.2 to 1.4 mol / liter, more preferably 0.4 to 1.2 mol / liter, from the viewpoint that chromium plating can be performed successfully.
　めっき液に含まれるｐＨ緩衝剤は、クロムめっきを行うときのｐＨを適切なものにして、クロムめっきを首尾よく行う目的で配合される。この目的に適したｐＨ緩衝剤としては例えばホウ酸、ホウ酸ナトリウム、ホウ酸カリウム、硫酸アンモニウム、リン酸、リン酸水素二ナトリウム、リン酸水素二カリウム、炭酸ナトリウム、及び炭酸水素ナトリウムなどが挙げられる。特にホウ酸、ホウ酸ナトリウム又はホウ酸カリウムを用いることが好ましい。これらの化合物は単独で用いることもでき、あるいは２種以上を組み合わせた緩衝系として用いることもできる。ｐＨ緩衝剤の配合量は、めっき液のｐＨを好ましくは０．５～２．０、更に好ましくは０．８～１．５に維持し得る量とすることができる。特にｐＨ緩衝剤としてホウ酸を用いると、ｐＨ緩衝作用のほかに、還元によって生成する金属クロムの結晶が微細化するという利点がある。 The pH buffer contained in the plating solution is blended for the purpose of successfully carrying out chrome plating by making the pH suitable for chrome plating. Suitable pH buffering agents for this purpose include, for example, boric acid, sodium borate, potassium borate, ammonium sulfate, phosphoric acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium carbonate, and sodium bicarbonate. . It is particularly preferable to use boric acid, sodium borate or potassium borate. These compounds can be used alone, or can be used as a buffer system combining two or more kinds. The blending amount of the pH buffering agent may be an amount that can maintain the pH of the plating solution preferably at 0.5 to 2.0, more preferably at 0.8 to 1.5. In particular, when boric acid is used as a pH buffer, in addition to the pH buffer action, there is an advantage that the metal chromium crystals produced by reduction are refined.
　めっき液に含まれるアミノカルボン酸化合物は、めっき液中において三価のクロムと錯体を形成し、めっき液の安定化を図る目的や、クロムめっきを首尾よく行う目的で配合される。アミノカルボン酸化合物は、分子中に少なくとも１個のアミノ基と、少なくとも１個のカルボキシル基とを有する化合物である。アミノカルボン酸化合物の例としては、グリシン、アラニン、アスパラギン酸、グルタミン酸、及びアルギニンなどが挙げられる。特にグリシン又はアラニンを用いることが好ましい。これらの化合物は１種又は２種以上を組み合わせて用いることができる。アミノカルボン酸化合物は、めっき液中の三価のクロム１ｍｏｌに対して、０．３～２ｍｏｌ、特に０．５～１．７ｍｏｌ配合されることが、安定したクロム錯体のめっき液が得られ、適正な電解めっきを行うことができる点から好ましい。同様の理由により、めっき液中のアミノカルボン酸化合物の濃度は、０．４～１．７ｍｏｌ／リットル、特に０．５～０．９ｍｏｌ／リットルとすることが好ましい。 The aminocarboxylic acid compound contained in the plating solution is blended for the purpose of forming a complex with trivalent chromium in the plating solution to stabilize the plating solution and to successfully perform chromium plating. An aminocarboxylic acid compound is a compound having at least one amino group and at least one carboxyl group in the molecule. Examples of the aminocarboxylic acid compound include glycine, alanine, aspartic acid, glutamic acid, and arginine. In particular, glycine or alanine is preferably used. These compounds can be used alone or in combination of two or more. When the aminocarboxylic acid compound is blended in an amount of 0.3 to 2 mol, particularly 0.5 to 1.7 mol, with respect to 1 mol of trivalent chromium in the plating solution, a stable plating solution of a chromium complex is obtained. This is preferable because proper electrolytic plating can be performed. For the same reason, the concentration of the aminocarboxylic acid compound in the plating solution is preferably 0.4 to 1.7 mol / liter, particularly 0.5 to 0.9 mol / liter.
　めっき液に含まれるスルファミン酸塩化合物は、めっき液において主として支持電解質としての役割を有し、めっき液の電気伝導度を所定のレベルに高める目的で配合される。またスルファミン酸塩化合物は、めっき液のｐＨ緩衝作用も有しているので、先に述べたｐＨ緩衝剤との併用でめっき液のｐＨが一層安定化する。更にスルファミン酸塩化合物は、三価のクロムが還元するときの触媒作用も有し、それによって金属クロムの結晶の微細化作用や、クロム皮膜の光沢作用が発現する。スルファミン酸塩としては、例えばスルファミン酸アンモニウム、スルファミン酸ナトリウム又はスルファミン酸カリウムを用いることができる。これらの化合物は１種又は２種以上を組み合わせて用いることができる。スルファミン酸塩は、めっき液中の三価のクロム１ｍｏｌに対して、０．３～２．５ｍｏｌ、特に０．５～２ｍｏｌ配合されることが好ましい。このような配合量にすることで、電解めっき時の電圧が下がり、めっき液の液温の上昇が抑制されて、めっき皮膜の特性に影響を及ぼす水酸化クロムの生成が抑制されるからである。またクロムめっきの表面調整作用の安定化及びめっき皮膜の析出の安定化を図ることができるからである。同様の理由により、めっき液中のスルファミン酸塩の濃度は、０．４～２．１ｍｏｌ／リットル、特に０．８～１．９ｍｏｌ／リットルとすることが好ましい。 The sulfamate compound contained in the plating solution mainly has a role as a supporting electrolyte in the plating solution, and is blended for the purpose of increasing the electrical conductivity of the plating solution to a predetermined level. Further, since the sulfamate compound also has a pH buffering action of the plating solution, the pH of the plating solution is further stabilized by the combined use with the pH buffer described above. Further, the sulfamate compound also has a catalytic action when trivalent chromium is reduced, thereby exhibiting the effect of refining metal chromium crystals and the effect of glossing the chromium film. As the sulfamate, for example, ammonium sulfamate, sodium sulfamate, or potassium sulfamate can be used. These compounds can be used alone or in combination of two or more. The sulfamate is preferably added in an amount of 0.3 to 2.5 mol, particularly 0.5 to 2 mol, with respect to 1 mol of trivalent chromium in the plating solution. By using such a blending amount, the voltage at the time of electrolytic plating decreases, the rise in the temperature of the plating solution is suppressed, and the production of chromium hydroxide that affects the properties of the plating film is suppressed. . Moreover, it is because the surface adjustment effect | action of chromium plating can be stabilized and the precipitation of a plating film can be stabilized. For the same reason, the concentration of sulfamate in the plating solution is preferably 0.4 to 2.1 mol / liter, particularly 0.8 to 1.9 mol / liter.
　めっき液に含まれるアミノカルボニル化合物は、分子中に少なくとも１個のカルボニル基と、少なくとも１個のアミノ基とを有する化合物である。アミノカルボニル化合物は、三価のクロムの還元速度を高める作用を有する。この理由は次のとおりであると考えられる。すなわち、三価のクロムが金属クロムに還元される過程では二価のクロムが生成する。二価のクロムは陰極上や電気二重層の中に吸着された状態で存在していると考えられる。三価のクロムから金属クロムへの還元は、二価のクロムの還元が律速段階になっている。本発明者の検討の結果、アミノカルボニル化合物は、二価のクロムが金属クロムに還元する速度を高める働きを有することが判明した。その結果、三価のクロムが金属クロムに還元する速度が高まったものと本発明者は考えている。 The aminocarbonyl compound contained in the plating solution is a compound having at least one carbonyl group and at least one amino group in the molecule. The aminocarbonyl compound has the effect of increasing the reduction rate of trivalent chromium. The reason is considered as follows. That is, in the process where trivalent chromium is reduced to metallic chromium, divalent chromium is generated. It is considered that divalent chromium is present adsorbed on the cathode or in the electric double layer. The reduction of trivalent chromium to metallic chromium is the rate-limiting step. As a result of the study by the present inventor, it was found that the aminocarbonyl compound has a function of increasing the rate at which divalent chromium is reduced to metallic chromium. As a result, the present inventor believes that the rate at which trivalent chromium is reduced to metallic chromium is increased.
　また、アミノカルボニル化合物は、三価のクロムのオール化を抑制する作用も有する。三価のクロムが金属クロムに還元される過程では、加水分解とオール化の反応が陰極付近で生じ、金属クロムの電析が阻害されることがある。めっき液中にアミノカルボニル化合物が存在すると、該化合物が三価のクロムと錯体を形成する。この錯形成反応は、三価のクロムのオール化との競争反応になるので、三価のクロムのオール化を最小限に抑えることができる。このことによっても三価のクロムの還元速度が高まる。 In addition, the aminocarbonyl compound has an action of suppressing the triation of trivalent chromium. In the process in which trivalent chromium is reduced to metallic chromium, hydrolysis and olation reactions occur near the cathode, which may inhibit metal chromium electrodeposition. When an aminocarbonyl compound is present in the plating solution, the compound forms a complex with trivalent chromium. Since this complex formation reaction is a competitive reaction with the trivalent chromium olation, the trivalent chromium olation can be minimized. This also increases the reduction rate of trivalent chromium.
　これらの有利な作用に加えて、アミノカルボニル化合物は、該化合物に含まれる窒素原子をめっき皮膜に供給して該めっき皮膜を硬質化したり、めっき液のｐＨを維持したりするｐＨ緩衝剤としての作用も有する。 In addition to these advantageous actions, the aminocarbonyl compound serves as a pH buffer that hardens the plating film by supplying nitrogen atoms contained in the compound to the plating film and maintains the pH of the plating solution. It also has an effect.
　特にアミノカルボニル化合物は、先に説明したスルファミン酸塩化合物と組み合わせて使用することによって顕著な効果を奏する。詳細には次のとおりである。本発明のめっき液においてスルファミン酸塩化合物を配合することの利点は成就したとおりであるところ、スルファミン酸塩化合物を用いることに起因してめっき皮膜の電着応力が増大する傾向にある。電着応力の増大はめっき皮膜にクラックを生じさせる原因となる。これに対して、スルファミン酸塩化合物とアミノカルボニル化合物とを共存させると、アミノカルボニル化合物によってクロムの結晶成長速度が速まるので、磁場の発達が阻害され、その結果、電着応力が低下する。これによってめっき皮膜にクラックが発生することが効果的に抑制される。かかる観点から、本発明で用いられるアミノカルボニル化合物に対するスルファミン酸塩の配合量はモル比で０．４～１．５の範囲であることが好ましい。 In particular, aminocarbonyl compounds have a remarkable effect when used in combination with the sulfamate compounds described above. Details are as follows. The advantages of blending the sulfamate compound in the plating solution of the present invention are as fulfilled, but the electrodeposition stress of the plating film tends to increase due to the use of the sulfamate compound. An increase in electrodeposition stress causes cracks in the plating film. On the other hand, when the sulfamate compound and the aminocarbonyl compound coexist, the growth rate of the chromium crystal is increased by the aminocarbonyl compound, so that the development of the magnetic field is inhibited, and as a result, the electrodeposition stress decreases. This effectively suppresses the occurrence of cracks in the plating film. From such a viewpoint, the blending amount of the sulfamate with respect to the aminocarbonyl compound used in the present invention is preferably in the range of 0.4 to 1.5 in terms of molar ratio.
　本発明において用いることのできるアミノカルボニル化合物としては、例えば尿素及びカルバミン酸などが挙げられる。これらの化合物は１種又は２種を組み合わせて用いることができる。特に尿素は、カルボニル基に対するα位の水素の酸性度が高いので、容易に水素を引き抜くことができるので好ましく用いられる。アミノカルボニル化合物は、めっき液中の三価のクロム１ｍｏｌに対して、０．５～３．０ｍｏｌ、特に１．１～２．２ｍｏｌ配合されることが、めっき時におけるめっき液中のクロム錯体の安定化、めっき皮膜の特性に影響を及ぼす水酸化クロムの生成の抑制、皮膜の緻密結晶化作用の促進などの点から好ましい。同様の理由により、めっき液中のアミノカルボニル化合物の濃度は、０．５～４．４ｍｏｌ／リットル、特に０．８～２．５ｍｏｌ／リットルとすることが好ましい。 Examples of aminocarbonyl compounds that can be used in the present invention include urea and carbamic acid. These compounds can be used alone or in combination. In particular, urea is preferably used because hydrogen at the α-position with respect to the carbonyl group has high acidity, and thus hydrogen can be easily extracted. The aminocarbonyl compound is blended in an amount of 0.5 to 3.0 mol, particularly 1.1 to 2.2 mol with respect to 1 mol of trivalent chromium in the plating solution. It is preferable from the viewpoints of stabilization, suppression of the formation of chromium hydroxide affecting the properties of the plating film, and promotion of the dense crystallization action of the film. For the same reason, the concentration of the aminocarbonyl compound in the plating solution is preferably 0.5 to 4.4 mol / liter, particularly 0.8 to 2.5 mol / liter.
　なお、先に述べた特許文献３にも、三価のクロムのめっき液に、アミノカルボニル化合物の一種である尿素を配合させることが記載されている。しかし、同文献において尿素を用いる理由は、尿素を分解させてアンモニアを生成させ、アンモニアによってめっき皮膜の耐水性を向上させることにある（特許文献３の〔００３３〕）。したがって同文献に記載のめっき液には尿素自体は存在していないか、又は存在していたとしてもその量は微量であると考えられる。また、同文献はクロメート化成処理液に関するものであり、めっき液に関する本発明とは、尿素の役割が全く相違している。 In addition, Patent Document 3 described above also describes that urea, which is a kind of aminocarbonyl compound, is added to a trivalent chromium plating solution. However, the reason for using urea in the same document is to decompose urea to generate ammonia, and to improve the water resistance of the plating film with ammonia ([0033] of Patent Document 3). Therefore, urea itself does not exist in the plating solution described in this document, or even if it exists, the amount thereof is considered to be very small. Further, this document relates to a chromate chemical conversion treatment solution, and the role of urea is completely different from the present invention relating to a plating solution.
　上述の各成分を有する本発明のめっき液によれば、三価のクロムが金属クロムに還元される速度が高まるので、工業的に満足し得る膜厚を有するめっき皮膜を容易に形成することができる。また、前記のアミノカルボニル化合物に由来する窒素原子がめっき皮膜中に取り込まれる結果、めっき皮膜の硬度が高まったり、耐食性や耐摩耗性等が高まったりするという有利な効果も奏される。更に、本発明のめっき液には、従来のめっき液に配合されていた成分である塩化アンモニウムを配合する必要がないので、塩化アンモニウムの分解に起因して生成する塩素ガスの発生を防止することができ、めっき作業の環境が改善される。この観点から、本発明のめっき液は、塩化アンモニウムを始めとするハロゲン化アンモニウムを含有していないことが好ましい。 According to the plating solution of the present invention having the above-described components, the rate at which trivalent chromium is reduced to metallic chromium is increased, so that a plating film having an industrially satisfactory film thickness can be easily formed. it can. In addition, as a result of the nitrogen atoms derived from the aminocarbonyl compound being taken into the plating film, advantageous effects such as an increase in the hardness of the plating film and an increase in corrosion resistance, wear resistance and the like are also exhibited. Furthermore, since it is not necessary to mix ammonium chloride, which is a component mixed in the conventional plating solution, with the plating solution of the present invention, generation of chlorine gas generated due to decomposition of ammonium chloride is prevented. This improves the plating work environment. From this viewpoint, the plating solution of the present invention preferably does not contain ammonium halide such as ammonium chloride.
　更に本発明のめっき液にはセラミック粒子を配合することもできる。セラミック粒子は、金属クロムの電析過程においてめっき皮膜中に取り込まれる。セラミック粒子は、主として粒界や欠陥に存在し、それによってクラックの伝播が抑えられ、疲労や破壊、剥離が効果的に緩和される。また、表面に露出したセラミックス粒子は相手摺動面との摩擦や摩耗作用において粒子自身が摺動面として相手摺動面と接触作用し、耐摩耗及び耐焼付けの向上や油膜形成の助けとなる。セラミック粒子はその平均粒径が０．２～１２μｍ、特に０．４～６．０μｍ、とりわけ０．５～３．０μｍであることが好ましい。セラミック粒子の平均粒径は、レーザー法粒度分布測定機（日機装社製ＭＩＣＲＯＴＲＡＣ　ＭＴ３０００ＩＩ）によって測定される。 Furthermore, ceramic particles can also be blended in the plating solution of the present invention. Ceramic particles are taken into the plating film during the metal chromium electrodeposition process. Ceramic particles are mainly present at grain boundaries and defects, thereby suppressing the propagation of cracks and effectively mitigating fatigue, breakage, and delamination. In addition, the ceramic particles exposed on the surface contact the mating sliding surface as a sliding surface in the friction and wear action with the mating sliding surface, which helps improve wear and seizure resistance and form an oil film. . The ceramic particles preferably have an average particle size of 0.2 to 12 μm, particularly 0.4 to 6.0 μm, particularly 0.5 to 3.0 μm. The average particle size of the ceramic particles is measured by a laser method particle size distribution analyzer (MICROTRAC MT3000II manufactured by Nikkiso Co., Ltd.).
　本発明のめっき液に配合されるセラミック粒子の平均粒径が前記の範囲内であると、めっき皮膜中に取り込まれたセラミック粒子の平均粒径が好ましくは０．２～８．０μｍ、更に好ましくは０．３～５．０μｍ、特に好ましくは０．５～３．０μｍとなり、先に述べた疲労や破壊、剥離が効果的に緩和される等の効果が一層顕著となる。めっき皮膜中のセラミック粒子の平均粒径は、レーザー顕微鏡（ＯＬＹＭＰＵＳ社製　ＯＬＳ１１００）によって測定される。 When the average particle size of the ceramic particles blended in the plating solution of the present invention is within the above range, the average particle size of the ceramic particles taken into the plating film is preferably 0.2 to 8.0 μm, more preferably Is 0.3 to 5.0 μm, particularly preferably 0.5 to 3.0 μm, and the effects such as fatigue, breakage, and exfoliation are alleviated as described above. The average particle diameter of the ceramic particles in the plating film is measured by a laser microscope (OLS1100 manufactured by OLYMPUS).
　粒径に関連して、セラミック粒子はその形状が、相手摺動面との摩擦や摩耗作用の向上の点から、球状等の形状であることが好ましい。 In relation to the particle size, the shape of the ceramic particles is preferably a spherical shape from the viewpoint of improving the friction with the mating sliding surface and the wear action.
　セラミック粒子としては、三価のクロムの還元に悪影響を及ぼさないものであればその種類に特に制限はない。めっき皮膜への取り込まれやすさの点からは、ゼータ電位が２０～１００ｍＶ、特に４０～７０ｍＶであるものを用いることが好ましい。そのようなセラミック粒子としては例えば、Ａｌ2Ｏ3、Ｓｉ3Ｎ4、ＡｌＮ、Ｃｒ3Ｃ2、Ｂ4Ｃ、ＴｉＣ、ＷＣ、ＴｉＯ2、Ｃｒ2Ｏ3、ＣＢＮ、Ｆｅ3Ｏ4などが挙げられる。これらのセラミック粒子は１種又は２種以上を組み合わせて用いることができる。セラミック粒子のゼータ電位は例えば、Ｚｅｔａｓｉｚｅｒ　Ｎａｎｏ　Ｓｅｒｉｅｓ（Ｍａｌｖｅｒｎ　Ｉｎｓｔｒｕｍｅｎｔｓ　Ｌｔｄ．社製）によって測定される。 The ceramic particles are not particularly limited as long as they do not adversely affect the reduction of trivalent chromium. From the viewpoint of easy incorporation into the plating film, it is preferable to use a zeta potential of 20 to 100 mV, particularly 40 to 70 mV. Examples of such ceramic particles include Al 2 O 3 , Si 3 N 4 , AlN, Cr 3 C 2 , B 4 C, TiC, WC, TiO 2 , Cr 2 O 3 , CBN, and Fe 3 O 4. Can be mentioned. These ceramic particles can be used alone or in combination of two or more. The zeta potential of the ceramic particles is measured by, for example, Zetasizer Nano Series (Malvern Instruments Ltd.).
　セラミック粒子は、本発明のめっき液中に、１０～１００ｇ／リットル、特に２０～６０ｇ／リットルとなるように配合されることが、めっき液の流動性が好適になるので、めっき皮膜へのセラミック粒子の取り込み量が適正量となる観点から好ましい。 The ceramic particles are blended in the plating solution of the present invention so as to be 10 to 100 g / liter, particularly 20 to 60 g / liter, because the fluidity of the plating solution is suitable. This is preferable from the viewpoint of obtaining an appropriate amount of particles.
　セラミック粒子は一般に比重が大きいことから、めっき液中において沈降しやすいことがある。また、粒径によってはセラミック粒子どうしがめっき液中において凝集することもある。これらのことを防止する観点から、めっき液中にセラミック粒子を配合する場合には、これとともに、凝集防止剤として塩化アルミニウムを配合することが好ましい。また、各種の界面活性剤を配合することも好ましい。界面活性剤としては、モノアルキル硫酸塩及びアルキルポリオキシエチレン硫酸塩等のアニオン性界面活性剤、アルキルトリメチルアンモニウム塩及びジアルキルジメチルアンモニウム塩等のカチオン性界面活性剤、ポリオキシエチレンアルキルエーテル及び脂肪酸ソルビタンエステル等のノニオン性界面活性剤等が挙げられる。 Ceramic particles generally have a large specific gravity, so they may easily settle in the plating solution. Depending on the particle size, ceramic particles may aggregate in the plating solution. From the viewpoint of preventing these problems, when the ceramic particles are blended in the plating solution, it is preferable to blend aluminum chloride as an aggregation inhibitor together with the ceramic particles. Moreover, it is also preferable to mix | blend various surfactant. Surfactants include anionic surfactants such as monoalkyl sulfates and alkylpolyoxyethylene sulfates, cationic surfactants such as alkyltrimethylammonium salts and dialkyldimethylammonium salts, polyoxyethylene alkyl ethers and fatty acid sorbitans. Nonionic surfactants such as esters are exemplified.
　これらの凝集防止剤のうち塩化アルミニウムは、セラミック粒子のゼータ電位をコントロールして粒子の分散性を向上させたり、粒子どうしの凝集を防止したりする有利な効果を発現する。また、セラミック粒子がめっき皮膜中へ均一に取り込まれやすくもなる。これらの効果を一層顕著なものとする観点から、塩化アルミニウムは、めっき液中の三価のクロム１ｍｏｌに対して、０．００５～０．５ｍｏｌ、特に０．０１～０．３ｍｏｌ配合されることが好ましい。同様の理由により、めっき液中の塩化アルミニウムの濃度は、０．０２～０．５ｍｏｌ／リットル、特に０．０５～０．３ｍｏｌ／リットルとすることが好ましい。 Among these anti-aggregating agents, aluminum chloride exhibits an advantageous effect of controlling the zeta potential of the ceramic particles to improve the dispersibility of the particles and preventing the particles from aggregating. Moreover, it becomes easy to take in ceramic particles uniformly in a plating film. From the viewpoint of making these effects even more prominent, 0.005 to 0.5 mol, particularly 0.01 to 0.3 mol, of aluminum chloride is added to 1 mol of trivalent chromium in the plating solution. Is preferred. For the same reason, the concentration of aluminum chloride in the plating solution is preferably 0.02 to 0.5 mol / liter, particularly 0.05 to 0.3 mol / liter.
　本発明のめっき液には水溶性有機溶剤を配合することもできる。水溶性有機溶剤の配合によって、めっきわたりを効果的に防止できる。また、めっき液中に、先に述べたセラミック粒子が配合されている場合には、該粒子の分散性が向上する。これらの観点から、水溶性有機溶剤は、めっき液中の三価のクロム１ｍｏｌに対して、０．４～２．１ｍｏｌ、特に０．６～１．３ｍｏｌ配合されることが好ましい。水溶性有機溶剤としては、例えばグリセリン、ポリエチレングリコール、エタノール、メタノール、及びｎ－プロパノールなどが挙げられる。 A water-soluble organic solvent can be added to the plating solution of the present invention. By blending the water-soluble organic solvent, it is possible to effectively prevent plating plating. Moreover, when the ceramic particle | grains mentioned previously are mix | blended in the plating solution, the dispersibility of this particle | grain improves. From these viewpoints, the water-soluble organic solvent is preferably blended in an amount of 0.4 to 2.1 mol, particularly 0.6 to 1.3 mol, with respect to 1 mol of trivalent chromium in the plating solution. Examples of the water-soluble organic solvent include glycerin, polyethylene glycol, ethanol, methanol, and n-propanol.
　本発明のめっき液は、上述のとおりｐＨ緩衝剤が含まれており、液のｐＨが好ましくは０．５～２．０、更に好ましくは０．８～１．５の範囲に保たれている。 The plating solution of the present invention contains a pH buffer as described above, and the pH of the solution is preferably kept in the range of 0.5 to 2.0, more preferably 0.8 to 1.5. .
　本発明のめっき液の媒体となる水としては、純水、イオン交換水、工業用水、水道水、蒸留水等が挙げられる。これらのうち、めっき液の保存安定性、皮膜特性に影響を及ぼさないことを前提として、経済性の面から、工業用水、水道水を使用することが好ましい。 Examples of water that serves as a medium for the plating solution of the present invention include pure water, ion exchange water, industrial water, tap water, and distilled water. Among these, it is preferable to use industrial water and tap water from the economical aspect on the premise that the storage stability of the plating solution and the film properties are not affected.
　本発明のめっき液には自己潤滑性を有する粒子、スルホン酸基含有化合物又はその塩を必要により含有させることが出来る。 The plating solution of the present invention can contain self-lubricating particles, sulfonic acid group-containing compounds or salts thereof as necessary.
　自己潤滑性を有する粒子を併用することにより、めっき皮膜の耐摩耗性を一層向上させることができる。自己潤滑性を有する粒子としては、例えばグラファイト、二硫化モリブデン、二硫化タングステン、フッ素樹脂、窒化ボロンなどが挙げられる。自己潤滑性を有する粒子は、本めっき液中に、５～７０ｇ／リットル、特に１０～５０ｇ／リットルである。 By using particles having self-lubricating properties in combination, the wear resistance of the plating film can be further improved. Examples of the self-lubricating particles include graphite, molybdenum disulfide, tungsten disulfide, fluororesin, and boron nitride. The self-lubricating particles are 5 to 70 g / liter, particularly 10 to 50 g / liter, in the plating solution.
　スルホン酸基含有化合物又はその塩は、皮膜の微小亀裂密度を増大させる作用を有し、優れた耐食性を付与することができる。スルホン酸基含有化合物又はその塩としては、、スルホン酸及びジスルホン酸並びにこれらの塩が好ましい。スルホン酸及びジスルホン酸の具体例として、脂肪族スルホン酸（例えばメタンスルホン酸、エタンスルホン酸等）、脂肪族ジスルホン酸（例えばメタンジスルホン酸、エタンジスルホン酸等）、芳香族スルホン酸（例えばベンゼンスルホン酸、ｐ－トルエンスルホン酸等）、芳香族ジスルホン酸（例えばベンゼンジスルホン酸等）等が挙げられる。
　スルホン酸基含有化合物又はその塩の濃度はスルホン酸基基準で０．０２～０．１ｍｏｌ／Ｌが好ましく、０．０４～０．０７ｍｏｌ／Ｌがより好ましい。 The sulfonic acid group-containing compound or a salt thereof has an action of increasing the microcrack density of the film, and can impart excellent corrosion resistance. As the sulfonic acid group-containing compound or a salt thereof, sulfonic acid and disulfonic acid and salts thereof are preferable. Specific examples of the sulfonic acid and disulfonic acid include aliphatic sulfonic acid (eg, methanesulfonic acid, ethanesulfonic acid, etc.), aliphatic disulfonic acid (eg, methanedisulfonic acid, ethanedisulfonic acid, etc.), aromatic sulfonic acid (eg, benzenesulfone, etc.). Acid, p-toluenesulfonic acid and the like) and aromatic disulfonic acid (eg benzene disulfonic acid and the like).
The concentration of the sulfonic acid group-containing compound or salt thereof is preferably 0.02 to 0.1 mol / L, more preferably 0.04 to 0.07 mol / L, based on the sulfonic acid group.
　本発明のめっき液には、上記以外の成分として、必要により当該技術分野で通常用いられる光沢剤、表面調整剤、コロイダルシリカ等の公知の添加剤を本発明の効果を損なわない範囲の添加量で含有させることができる。 In the plating solution of the present invention, as a component other than the above, known additives such as brighteners, surface conditioners, colloidal silica and the like that are usually used in the technical field as necessary are added within a range not impairing the effects of the present invention It can be made to contain.
　以上の各成分を含むめっき液を用いてクロムめっきを行う条件としては、めっき浴の温度を好ましくは３０～６０℃、更に好ましくは４０～６０℃に設定する。電流密度は好ましくは１５～６０Ａ／ｄｍ2、更に好ましくは２０～４０Ａ／ｄｍ2に設定する。陽極としては、黒鉛や各種の寸法安定化陽極（ＤＳＡ）、例えばＴｉ－Ｐｔ電極などを用い、陰極としては、めっきの対象物を用いることができる。 As a condition for performing chromium plating using a plating solution containing the above components, the temperature of the plating bath is preferably set to 30 to 60 ° C., more preferably 40 to 60 ° C. The current density is preferably set to 15 to 60 A / dm 2 , more preferably 20 to 40 A / dm 2 . As the anode, graphite or various dimensionally stabilized anodes (DSA) such as a Ti—Pt electrode can be used, and as the cathode, an object to be plated can be used.
　上述の条件下に電解めっきによって形成されためっき皮膜においては、クロムは一般に非晶質となっている。非晶質のクロムのめっき皮膜はその硬度が結晶質のものに比較して低い傾向にある。そこで、電解めっきによって形成されためっき皮膜を熱処理することによって結晶化して、結晶質のクロムの皮膜とすることができる。熱処理の条件としては、大気下に１５０～６００℃、好ましくは２００～６００℃、一層好ましくは２００～４５０℃とすることが好ましい。加熱時間は、温度がこの範囲であることを条件として、３０～６０分とすることが好ましい。 In the plating film formed by electrolytic plating under the above conditions, chromium is generally amorphous. Amorphous chromium plating films tend to have lower hardness than crystalline ones. Therefore, the plating film formed by electrolytic plating can be crystallized by heat treatment to form a crystalline chromium film. The conditions for the heat treatment are preferably 150 to 600 ° C., preferably 200 to 600 ° C., more preferably 200 to 450 ° C. in the atmosphere. The heating time is preferably 30 to 60 minutes, provided that the temperature is within this range.
　前記の条件下での電解めっきによって得られるめっき皮膜は、工業的に満足し得る膜厚をもつ。その膜厚は好ましくは３～３００μｍ、更に好ましくは５～１００μｍである。また、前記の条件下での電解めっきによって得られるめっき皮膜は、耐摩耗性及び耐食性等の皮膜特性に優れる。したがって、本発明の三価クロムめっき液を用い、各種の部材、特にピストンリング、ロール、ショックアブソーバ等の摺動部材に対してめっきを施すことによって、これらの部材に必要な特性を付与することができる。 The plating film obtained by electrolytic plating under the above conditions has an industrially satisfactory film thickness. The film thickness is preferably 3 to 300 μm, more preferably 5 to 100 μm. Moreover, the plating film obtained by electrolytic plating under the above-described conditions is excellent in film properties such as wear resistance and corrosion resistance. Therefore, by using the trivalent chromium plating solution of the present invention and plating various members, particularly sliding members such as piston rings, rolls, shock absorbers, and the like, the necessary characteristics are imparted to these members. Can do.
　以下、実施例により本発明を更に詳細に説明する。しかしながら本発明の範囲は、かかる実施例に制限されない。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.
　　〔実施例１ないし３並びに比較例１及び２〕
　以下の表１に示す成分を水に添加して、同表に示す組成を有する三価のクロムのめっき液を調製した。得られためっき液を用い、同表に示す条件で電解めっきを行った。陽極としては高密度黒鉛板を用いた。陰極としてはＳ４５Ｃみがき鋼板を用いた。 [Examples 1 to 3 and Comparative Examples 1 and 2]
The components shown in Table 1 below were added to water to prepare a trivalent chromium plating solution having the composition shown in the same table. Using the obtained plating solution, electrolytic plating was performed under the conditions shown in the same table. A high density graphite plate was used as the anode. An S45C polished steel plate was used as the cathode.
　　〔比較例３〕
　以下の表１に示す成分を水に添加して、同表に示す組成を有する六価のクロムのめっき液を調製した。得られためっき液を用い、同表に示す条件で電解めっきを行った。陰極は実施例１と同様のものを用いた。陽極としては鉛錫板を用いた。 [Comparative Example 3]
The components shown in Table 1 below were added to water to prepare a hexavalent chromium plating solution having the composition shown in the same table. Using the obtained plating solution, electrolytic plating was performed under the conditions shown in the same table. The same cathode as in Example 1 was used. A lead tin plate was used as the anode.
　得られためっき物におけるクロムめっき皮膜の厚みを以下の方法で測定した。また、めっき皮膜の表面の外観を目視観察して光沢の程度及びクラックの発生の有無を評価した。更に以下の方法で、めっき皮膜のビッカース硬度を測定し、耐摩耗性及び耐食性を以下の方法で評価した。更に実施例２及び３並びに比較例２については、めっき皮膜中のセラミック粒子の分散度を以下の方法で評価した。それらの結果を以下の表１に示す。 The thickness of the chromium plating film in the obtained plated product was measured by the following method. Further, the appearance of the surface of the plating film was visually observed to evaluate the degree of gloss and the presence or absence of cracks. Further, the Vickers hardness of the plating film was measured by the following method, and the wear resistance and corrosion resistance were evaluated by the following methods. Further, for Examples 2 and 3 and Comparative Example 2, the degree of dispersion of the ceramic particles in the plating film was evaluated by the following method. The results are shown in Table 1 below.
　　〔めっき皮膜の厚み〕
　めっき皮膜の皮膜断面を、レーザー顕微鏡（ＯＬＹＭＰＵＳ社製　ＬＥＸＴＯ　ＯＬＳ１１００）を用いて４００倍の倍率で測定した。 [Thickness of plating film]
The cross section of the plating film was measured at a magnification of 400 times using a laser microscope (LEXTO OLS1100 manufactured by OLYMPUS).
　　〔めっき皮膜のビッカース硬度〕
　めっき皮膜の皮膜断面を、微小硬さ試験機（ミツトヨ製　ＨＭ－１０３）を用いて、荷重２００ｇｆ×１５ｓｅｃで測定した。 [Vickers hardness of plating film]
The cross section of the plating film was measured with a load of 200 gf × 15 sec using a micro hardness tester (HM-103 manufactured by Mitutoyo Corporation).
　　〔めっき皮膜の耐摩耗性〕
　科研式腐食摩耗試験機を用いてめっき皮膜の耐摩耗性を評価した。摩擦の相手となるライナー材として鋳鉄（ＪＩＳ　Ｇ　５５０１－１９９５に準拠したＦＣ２５０）を用いた。摩擦試験器における接触荷重は３９Ｎとした。摩擦速度は０．２５ｍ／ｓｅｃ、摩擦距離は５４００ｍ（＝６時間）とした。腐食液として硫酸水溶液（ｐＨ＝２．０）を用い、１．５ｍｌ／ｍｉｎで滴下した。腐食液温度は常温とした。めっき皮膜の摩耗量を測定し、その値を耐摩耗性の指標とした。 [Abrasion resistance of plating film]
The wear resistance of the plating film was evaluated using a Kaken type corrosion wear tester. Cast iron (FC250 conforming to JIS G 5501-1995) was used as a liner material to be a friction partner. The contact load in the friction tester was 39N. The friction speed was 0.25 m / sec, and the friction distance was 5400 m (= 6 hours). A sulfuric acid aqueous solution (pH = 2.0) was used as a corrosive solution and dropped at 1.5 ml / min. The temperature of the corrosive liquid was normal temperature. The amount of wear of the plating film was measured, and the value was used as an index of wear resistance.
　　〔めっき皮膜の耐食性〕
　めっき物におけるめっき皮膜の面積が１ｃｍ2となるようにし、該めっき物を所定のｐＨに調整された硫酸及び塩酸水溶液（容積１リットル）中に、ビニール製の釣糸で吊り下げた。水溶液の温度を７０℃に保ち、水溶液を１時間にわたって攪拌した。その後、水溶液中に溶解したクロムの量をＩＣＰ発光分析装置（島津製作所社製　ＩＣＰＳ－７５１０）によって測定し、耐食性の尺度とした。 [Corrosion resistance of plating film]
The area of the plating film in the plated product was 1 cm 2 , and the plated product was suspended in a sulfuric acid and hydrochloric acid aqueous solution (volume: 1 liter) adjusted to a predetermined pH with a vinyl fishing line. The temperature of the aqueous solution was kept at 70 ° C., and the aqueous solution was stirred for 1 hour. Thereafter, the amount of chromium dissolved in the aqueous solution was measured by an ICP emission spectrometer (ICPS-7510 manufactured by Shimadzu Corporation), and used as a measure of corrosion resistance.
　　〔めっき皮膜中のセラミック粒子の分散度〕
　ここでいう分散度とは、めっき皮膜の断面を観察したときに、単位面積あたりの観察視野に占めるセラミック粒子の面積率のことである。この面積率は次の方法で測定される。すなわち、めっき皮膜の縦断面を、レーザー顕微鏡（ＯＬＹＭＰＵＳ社製　ＬＥＸＴＯ　ＯＬＳ１１００）を用いて、１０００倍の倍率で観察する。そして、３０μｍ四方の枠内に存在するセラミック粒子が占有する面積の比率を、同レーザー顕微鏡を用いて処理計測する。 [Dispersion degree of ceramic particles in plating film]
The dispersity referred to here is the area ratio of ceramic particles in the observation field per unit area when the cross section of the plating film is observed. This area ratio is measured by the following method. That is, the longitudinal section of the plating film is observed at a magnification of 1000 times using a laser microscope (LEXTO OLS1100 manufactured by OLYMPUS). And the ratio of the area which the ceramic particle which exists in a 30 micrometer square frame occupies is process-measured using the laser microscope.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示す結果から明らかなように、各実施例のめっき液を用いてクロムの電解めっきを行うと、比較例のめっき液を用いた場合に比べて同じめっき時間で厚いめっき皮膜を形成できることが判る。また、各実施例のめっき液を用いて得られためっき皮膜の表面外観は良好であり、光沢を有するものであることが判る。特に、実施例１ないし３と比較例３との対比から明らかなように、三価のクロムのめっき液を用いても、従来用いられていた六価のクロムのめっき液を用いた場合と同様又はそれ以上の性能を有するめっき皮膜が得られることが判る。 As is clear from the results shown in Table 1, when electrolytic plating of chromium is performed using the plating solution of each example, a thick plating film can be formed in the same plating time as compared with the case of using the plating solution of the comparative example. I understand. Moreover, it turns out that the surface appearance of the plating film obtained using the plating solution of each Example is favorable and has glossiness. In particular, as is clear from the comparison between Examples 1 to 3 and Comparative Example 3, the use of a trivalent chromium plating solution is the same as the case of using a hexavalent chromium plating solution that has been used conventionally. Or it turns out that the plating film which has the performance beyond it is obtained.
　また、スルファミン酸塩化合物及びアミノカルボニル化合物を含む各実施例のめっき液を用いると、得られためっき皮膜にクラックが生じていないことが判る。これに対してアミノカルボニル化合物を配合せず、スルファミン酸塩化合物だけを含む比較例１及び２にめっき液を用いると、得られためっき皮膜にクラックが生じてしまう。 It can also be seen that when the plating solution of each example containing a sulfamate compound and an aminocarbonyl compound is used, no cracks are generated in the obtained plating film. On the other hand, when the plating solution is used in Comparative Examples 1 and 2 containing only the sulfamate compound without adding an aminocarbonyl compound, cracks are generated in the obtained plating film.
　更に、実施例１と、実施例２及び３との対比から明らかなように、めっき液中にセラミック粒子を配合することで、めっき皮膜の耐摩耗性が一層向上することが判る。その上、セラミック粒子を配合しためっき液どうしを比較すると、実施例２及び３と比較例２とでは、実施例２及び３のめっき液を用いた方が、めっき皮膜の耐摩耗性が高いことが判る。この理由は、実施例２及び３では、めっき液中にスルファミン酸塩化合物及びアミノカルボニル化合物の双方が配合されているからであると考えられる。 Furthermore, as is clear from the comparison between Example 1 and Examples 2 and 3, it can be seen that the wear resistance of the plating film is further improved by mixing ceramic particles in the plating solution. In addition, when the plating solutions containing ceramic particles are compared, in Examples 2 and 3 and Comparative Example 2, the plating solutions of Examples 2 and 3 have higher wear resistance of the plating film. I understand. The reason for this is considered to be that in Examples 2 and 3, both the sulfamate compound and the aminocarbonyl compound are blended in the plating solution.
｛実施例４｝
　実施例３で得られためっき物を大気下に４００℃で１時間加熱処理を行った。実施例１～３と同様にしてビッカース硬度を測定したところ１５５０であり、加熱処理前に比べて高い硬度のめっき皮膜が形成されていることを確認した。 {Example 4}
The plated product obtained in Example 3 was heat-treated at 400 ° C. for 1 hour in the atmosphere. When the Vickers hardness was measured in the same manner as in Examples 1 to 3, it was 1550, and it was confirmed that a plating film having a higher hardness than that before the heat treatment was formed.
　本発明によれば、工業的に満足し得る膜厚をもち、耐食性及び耐摩耗性等の皮膜特性に優れたクロムめっきを形成することのできる三価クロムめっき液が提供される。また、本発明によれば、液中成分の分解によるハロゲンガス等の有害ガスの発生が抑えられるため、長期保存性に優れ、作業環境の改善につながる三価クロムめっき液が提供される。 According to the present invention, there is provided a trivalent chromium plating solution having an industrially satisfactory film thickness and capable of forming a chromium plating excellent in film properties such as corrosion resistance and wear resistance. Further, according to the present invention, since generation of harmful gas such as halogen gas due to decomposition of components in the liquid can be suppressed, a trivalent chromium plating solution that is excellent in long-term storage and leads to improvement of the working environment is provided.

Claims (14)

  1. 　三価クロム化合物、ｐＨ緩衝剤、アミノカルボン酸化合物、スルファミン酸塩化合物及びアミノカルボニル化合物を含有する水溶液からなる三価クロムめっき液。 A trivalent chromium plating solution comprising an aqueous solution containing a trivalent chromium compound, a pH buffer, an aminocarboxylic acid compound, a sulfamate compound and an aminocarbonyl compound.
  2. 　セラミック粒子を更に含有する請求項１に記載の三価クロムめっき液。 The trivalent chromium plating solution according to claim 1, further comprising ceramic particles.
  3. 　セラミック粒子の凝集防止剤を更に含有する請求項２に記載の三価クロムめっき液。 The trivalent chromium plating solution according to claim 2, further comprising an anti-aggregation agent for ceramic particles.
  4. 　前記三価クロム化合物が、塩化クロム、硝酸クロム、硫酸クロム及びリン酸クロムのうちの少なくとも一種である請求項１ないし３のいずれか一項に記載の三価クロムめっき液。 The trivalent chromium plating solution according to any one of claims 1 to 3, wherein the trivalent chromium compound is at least one of chromium chloride, chromium nitrate, chromium sulfate and chromium phosphate.
  5. 　前記ｐＨ緩衝剤が、ホウ酸、ホウ酸ナトリウム又はホウ酸カリウムである請求項１ないし４のいずれか一項に記載の三価クロムめっき液。 The trivalent chromium plating solution according to any one of claims 1 to 4, wherein the pH buffer is boric acid, sodium borate, or potassium borate.
  6. 　前記アミノカルボン酸化合物が、グリシン又はアラニンである請求項１ないし５のいずれか一項に記載の三価クロムめっき液。 The trivalent chromium plating solution according to any one of claims 1 to 5, wherein the aminocarboxylic acid compound is glycine or alanine.
  7. 　前記スルファミン酸塩化合物が、スルファミン酸アンモニウム、スルファミン酸ナトリウム又はスルファミン酸カリウムである請求項１ないし６のいずれか一項に記載の三価クロムめっき液。 The trivalent chromium plating solution according to any one of claims 1 to 6, wherein the sulfamate compound is ammonium sulfamate, sodium sulfamate, or potassium sulfamate.
  8. 　前記アミノカルボニル化合物が、尿素及びカルバミン酸のうちの少なくとも一種である請求項１ないし７のいずれか一項に記載の三価クロムめっき液。 The trivalent chromium plating solution according to any one of claims 1 to 7, wherein the aminocarbonyl compound is at least one of urea and carbamic acid.
  9. 　前記セラミック粒子が、２０～１００ｍＶのゼータ電位を有するものである請求項２に記載の三価クロムめっき液。 The trivalent chromium plating solution according to claim 2, wherein the ceramic particles have a zeta potential of 20 to 100 mV.
  10. 　前記凝集防止剤が、塩化アルミニウムである請求項３に記載の三価クロムめっき液。 The trivalent chromium plating solution according to claim 3, wherein the aggregation preventing agent is aluminum chloride.
  11. 　摺動部材のめっき液として用いられる請求項１ないし１０のいずれか一項に記載の三価クロムめっき液。 The trivalent chromium plating solution according to any one of claims 1 to 10, which is used as a plating solution for a sliding member.
  12. 　摺動部材がピストンリング、ロール及びショックアブソーバから選ばれる請求項１１に記載の三価クロムめっき液。 The trivalent chromium plating solution according to claim 11, wherein the sliding member is selected from a piston ring, a roll, and a shock absorber.
  13. 　請求項１ないし１２のいずれか一項に記載の三価クロムめっき液を用いるクロムめっき方法。 A chromium plating method using the trivalent chromium plating solution according to any one of claims 1 to 12.
  14. 　請求項１ないし１２のいずれか一項に記載の三価クロムめっき液を用いて形成された皮膜を加熱処理するクロムめっき方法。 A chromium plating method for heat-treating a film formed using the trivalent chromium plating solution according to any one of claims 1 to 12.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014126067A1 (en) * 2013-02-13 2014-08-21 日本化学工業株式会社 Trivalent chromium plating solution
WO2014157305A1 (en) 2013-03-29 2014-10-02 株式会社リケン Composite rigid chromium coating film, and sliding member coated with said coating film
CN105506713A (en) * 2014-09-25 2016-04-20 通用电气公司 Method for formation of chromium based coating by electroplating, used electrolyte solution and formed coating
WO2022044451A1 (en) * 2020-08-27 2022-03-03 日立Astemo株式会社 Shock absorber and manufacturing method for shock absorber
WO2024053640A1 (en) * 2022-09-07 2024-03-14 日立Astemo株式会社 Plated member and method for producing same

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4083268A1 (en) 2021-04-30 2022-11-02 Atotech Deutschland GmbH & Co. KG Electroplating composition for depositing a chromium or chromium alloy layer on a substrate
EP4101947A1 (en) 2021-06-10 2022-12-14 Atotech Deutschland GmbH & Co. KG Method for electrodepositing a dark chromium layer, substrate comprising same, and electroplating bath thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5531119A (en) * 1978-08-25 1980-03-05 Toyo Soda Mfg Co Ltd Chrome plating bath
JPS5531122A (en) * 1978-08-25 1980-03-05 Toyo Soda Mfg Co Ltd Chrome plating bath
JPS62120498A (en) * 1985-11-19 1987-06-01 Matsufumi Takatani Composite chromium plating and plating method
JPH0995793A (en) * 1995-09-29 1997-04-08 Shigeo Hoshino Tervalent chromium plating bath depositing chromium plating having thermally hardening property

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5531119A (en) * 1978-08-25 1980-03-05 Toyo Soda Mfg Co Ltd Chrome plating bath
JPS5531122A (en) * 1978-08-25 1980-03-05 Toyo Soda Mfg Co Ltd Chrome plating bath
JPS62120498A (en) * 1985-11-19 1987-06-01 Matsufumi Takatani Composite chromium plating and plating method
JPH0995793A (en) * 1995-09-29 1997-04-08 Shigeo Hoshino Tervalent chromium plating bath depositing chromium plating having thermally hardening property

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2014126067A1 (en) * 2013-02-13 2017-02-02 日本化学工業株式会社 Trivalent chromium plating solution
WO2014126066A1 (en) 2013-02-13 2014-08-21 日本化学工業株式会社 Piston ring and method for producing same
EP2957660A4 (en) * 2013-02-13 2016-11-30 Riken Kk Piston ring and method for producing same
JP5636140B1 (en) * 2013-02-13 2014-12-03 日本化学工業株式会社 Piston ring and manufacturing method thereof
WO2014126067A1 (en) * 2013-02-13 2014-08-21 日本化学工業株式会社 Trivalent chromium plating solution
CN105143520A (en) * 2013-02-13 2015-12-09 日本化学工业株式会社 Piston ring and method for producing same
EP2980280A4 (en) * 2013-03-29 2016-12-07 Kk Riken Composite rigid chromium coating film, and sliding member coated with said coating film
US9850587B2 (en) 2013-03-29 2017-12-26 Kabushiki Kaisha Riken Hard composite chromium plating film and sliding member coated with such film
CN105051261A (en) * 2013-03-29 2015-11-11 株式会社理研 Composite rigid chromium coating film, and sliding member coated with said coating film
WO2014157305A1 (en) 2013-03-29 2014-10-02 株式会社リケン Composite rigid chromium coating film, and sliding member coated with said coating film
CN105506713A (en) * 2014-09-25 2016-04-20 通用电气公司 Method for formation of chromium based coating by electroplating, used electrolyte solution and formed coating
WO2022044451A1 (en) * 2020-08-27 2022-03-03 日立Astemo株式会社 Shock absorber and manufacturing method for shock absorber
JP7409998B2 (en) 2020-08-27 2024-01-09 日立Astemo株式会社 Buffer and buffer manufacturing method
WO2024053640A1 (en) * 2022-09-07 2024-03-14 日立Astemo株式会社 Plated member and method for producing same

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