JP2009242851A - Method for preventing nickel elution from liquid contact instrument made of copper alloy and protective film forming agent for prevention of nickel elution, and detergent for prevention of nickel elution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preventing nickel elution from a liquid-contact instrument made of a copper alloy, by which elution of nickel is prevented, for example, valves for city water, valves for water or hot-water supply, pipe joints, strainers, water faucet metal, pump equipment, water meters, water cleaners, water or hot-water supply apparatus and other liquid-contact instruments made of copper alloys such as bronze and brass treated with nickel-containing plating, even when the instruments are in contact with a fluid such as city water, and to provide a protective film forming agent for prevention of nickel elution and a detergent for prevention of nickel elution. <P>SOLUTION: The method for preventing nickel elution in a liquid-contact instrument made of a copper alloy treated with nickel-containing plating includes: applying a protective film forming agent on at least a liquid-contact face of the liquid-contact instrument, the film forming agent comprising a protective film forming component containing wax and a solvent component that dissolves the protective film forming component in water thereby forming a protective film; and suppressing elution of nickel by the protective film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nickel elution prevention method, a nickel elution prevention protective film forming agent, and a nickel elution prevention cleaning agent for a copper alloy wetted device.

  Usually, in the middle or at the end of pipes for water supply and hot water supply, water supply valves, water supply and hot water supply valves, pipe fittings, strainers, faucet fittings, pump supplies, water meters, water purifiers, water heaters, Other wetted parts are provided, and these wetted parts are often made of copper alloys such as bronze and brass which are excellent in castability, machinability and economy. In particular, for bronze and brass valves and fittings, lead is used to improve castability and machinability for bronze and to improve machinability and hot forgeability for brass. A fixed amount of alloy is used. However, if fluid such as tap water is supplied to bronze / brass wetted parts containing lead, the lead part of the lead-containing metal deposited on the surface layer of the wetted part may be eluted into the tap water. There is.

  Therefore, tap water provided for drinking must conform to and comply with water quality standards for lead elution by a specific evaluation method. Since lead is a harmful substance to the human body, it is necessary to reduce the amount of leaching as much as possible. In April 2003, regulations on lead leaching standards were strengthened. Under such circumstances, at present, a wetted copper alloy material manufactured using a so-called lead-less material in which lead is removed from the material, a conventional material containing lead, an acid cleaning treatment, or an alkali cleaning treatment, etc. Copper alloy wetted parts with reduced lead elution by performing various surface treatments are in circulation.

  As this type of lead elution reduction technique, for example, there is a lead elution prevention treatment method described in JP-A-2002-180267 (Patent Document 1). The document 1 discloses a technique for preventing lead elution by immersing a metal fitting for water supply and drainage in various benzotriazole-based compound solutions to form a strong film on the surface of the metal fitting.

  In addition, the lead elution prevention treatment method described in Japanese Patent Application Laid-Open No. 2001-152369 (Patent Document 2) is performed by immersing a metal fitting for water supply and drainage in an etching treatment solution containing an organic carboxylic acid or a salt thereof, and lead on the surface of the metal fitting. It is disclosed as a technique for removing.

  Furthermore, in addition to the improvement of lead elution described above, improvement of nickel elution that affects the human body is becoming an urgent task. Valves, fittings, strainers, faucet fittings, and other wetted parts are subjected to various plating treatments including nickel plating for the purpose of improving the external surface appearance, corrosion resistance, and wear resistance. Yes. For example, nickel plating, nickel alloy plating, nickel chrome plating, and the like can be mentioned. When plating processing including these nickel is performed, the plating wraps around and adheres to the mouth portion of the liquid contact device.

  FIG. 1 is a cross-sectional view of a JIS horizontal water faucet (manufactured by CAC406) that has been subjected to nickel chromium plating, and FIG. 2 is a partial enlarged cross-sectional view of the mouth portion shown in FIG. As shown in FIG. 2, the chrome plating 2 a and the nickel plating 2 b that is not in a multilayer state exist at the mouth portion of the wetted device 1 that has been plated 2. This is because the nickel plating 2b wraps around the inside of the mouth rather than the chromium plating 2a due to the difference in the current density range. In this state, when a fluid such as tap water is supplied to the wetted parts 1, There is a possibility that the nickel plating 2b exposed and adhered to the portion 1a may be eluted into the fluid.

  FIG. 3 is an enlarged cross-sectional view of part B of FIG. 2, and as shown in the figure, copper (a wetted part 1a) having a high corrosion potential and nickel (nickel plating 2b) having a low corrosion potential. When a fluid such as tap water with good electrical conductivity comes into contact with the two in contact with each other, it becomes electrically conductive and nickel having a low corrosion potential (nickel plating 2b) is caused by copper having a high corrosion potential (wetted part 1a). Corrosion reaction takes place under the anodic polarization, and the dissimilar metal contact corrosion that the oxidation dissolution of nickel is promoted occurs. Further, the nickel plating 2b has a large number of pinholes 2c, and some of them reach the copper surface which is the base of the nickel plating 2b. A fluid such as tap water with good electrical conductivity enters this, and contact with different metals also occurs at this site. Furthermore, the nickel plating 2b adhering to the liquid contact portion 1a is also eluted from the nickel plating 2b itself by contacting the fluid.

  As a current nickel elution reduction technique, for example, there is a nickel elution reduction processing method described in JP-A-2002-155391 (Patent Document 3). This treatment method includes a treatment step of performing chromium plating after at least nickel plating on a water supply device made of copper or copper alloy, and then removing the nickel plating protruding from the chromium plating. In this treatment step, There has been disclosed a technique for immersing a water supply device in an oxidizing chemical such as sulfuric acid that dissolves and removes only nickel plating, and dissolves and removes the nickel plating portion that has wrapped around the mouth when nickel chrome plating is performed.

  Japanese Patent No. 2836987 (Patent Document 4) discloses a technique for preventing nickel elution by forming a thin film of an aliphatic unsaturated carboxylic acid on nickel plating applied to a ceramic substrate on which an electronic component is mounted. ing.

JP 2002-180267 A JP 2001-152369 A JP 2002-155391 A Japanese Patent No. 2836987

  However, in Patent Documents 1 and 2 for the purpose of reducing lead elution described above, the lead leaching test described in these publications is JIS S3200-7 (1997) “Water Supply Equipment—Leaching Performance Test Method”. In addition, it is unclear how much the amount of the leachate leached out is unknown, and the technical effect cannot be confirmed.

  Further, in Japanese Patent Application Laid-Open No. 2002-155391 (Patent Document 3) for the purpose of reducing nickel elution, the nickel plating protruding from the chromium plating cannot be effectively removed, and the nickel plating is not applied to the liquid contact portion. Because it always remains, elution of nickel components due to contact corrosion of different metals in this part, which became electrically conductive through a fluid such as tap water, and elution from the nickel plating itself occurred, so the nickel leaching standard was met. It cannot be satisfied. In addition, since the plating is peeled off, the ingot, which is copper, is exposed, and there is a problem that lead segregated in the surface layer is eluted. Furthermore, although the nickel leaching test described in the publication is based on JIS S3200-7 (1997) “Equipment for water supply-leaching performance test method”, it is unclear how much the amount of leachate was leached. Therefore, the technical effect of nickel removal cannot be determined.

  Moreover, since JIS S3200-7, which is the evaluation test, is a Ni leaching test with simulated tap water, when this test is performed, the wetted equipment deteriorates due to components contained in the simulated tap water, In test work (water flow work and cleaning work), it is necessary to contain components that do not deteriorate due to physical influence, and higher lead / nickel elution prevention performance is required.

  The present inventors have further elucidated the causes of lead elution and nickel elution in this type of field. FIG. 4 is a photograph showing nickel distribution by EPMA (X-ray microanalyzer) having an inner diameter of 40A and an inner volume of 40 ml, which is subjected to nickel chrome plating treatment shown in FIG. FIG. 5 is a photograph showing the lead distribution. In FIG. 1, reference numeral 3 denotes an EPMA (X-ray microanalyzer) analysis unit. The acceleration voltage of EPMA (X-ray microanalyzer) measurement was 30 KV, and the irradiation current was 10 nA. As shown in FIGS. 4 and 5, in the inner surface (CAC406 surface) 1a of the specimen 1 subjected to nickel chrome plating, nickel and lead exist partially and substantially at the same position on the measurement surface. As is clear from the electron micrograph of FIG. 6, the positions of both elements coincide with the crystal grain boundary positions on the metal surface.

  FIG. 7 is an explanatory view showing the presence of lead and nickel on the inner surface of a device in which nickel plating or the like is applied to the outer surface of a water supply device or the like. Valves, pipe joints, strainers, faucet fittings or other water supply devices having complicated flow paths are formed by sand casting using a copper alloy material. The cast surface thus cast has a lot of irregularities, and the lead 5 that has moved from the crystal grain boundary 4 or the like to the surface layer during solidification is segregated in the indentation. In particular, the inner surface layer of the water supply device that is not subjected to surface processing is prominent, and when plating is performed in this state, the plating solution remains on the lead 5 in the indented portion and dries, which is different from metallic nickel. It is thought that the nickel salt 6 adheres. Since water supply equipment such as a faucet fitting has a complicated flow path, it is difficult to remove the plating solution remaining in the interior, and therefore, it is considered that the nickel salt 6 adheres significantly. In this state, when a fluid such as tap water is supplied to the water supply device, lead 5 and nickel salt 6 are eluted.

  This is not considered at all in the prior art including the above-mentioned patent document. For example, even if the technology of Patent Document 1 is adopted, as shown in FIG. Even if a film of benzotriazole 33 is formed on 31, it is not sufficient to prevent lead elution, and as shown in FIG. As a result, after the elution of the nickel salt 32 proceeds, a large amount of segregated lead 31 underneath is eluted, and it is not possible to prevent the elution of lead as well as the elution of nickel. .

  The technique disclosed in Patent Document 4 is a technique related to so-called electroless plating in which a non-metal such as ceramic is plated, so that the technique is applied as it is, unlike technical means for performing metal plating on a metal base. It is not possible.

  The present invention has been developed as a result of intensive studies in view of the above-described circumstances, and the object of the present invention is, for example, waterworks made of copper alloys such as bronze and brass that have been plated with nickel For valves, water supply and hot water supply valves, pipe fittings, strainers, faucet fittings, pump supplies, water meters, water purifiers, water heaters, and other wetted parts, even if fluids such as tap water come into contact, An object of the present invention is to provide a nickel elution prevention method, a nickel elution prevention protective film forming agent, and a nickel elution prevention cleaning agent for a copper alloy wetted device in which nickel does not elute.

  In order to achieve the above object, the invention according to claim 1 is the nickel elution prevention method in which the copper alloy wetted parts are plated with nickel, and wax is applied to at least the wetted surfaces of the wetted parts. A protective film forming agent containing a protective film forming component and a solvent component that dissolves the protective film forming component in water is applied to form a protective film, and the protective film suppresses elution of nickel. This is a nickel elution prevention method for copper alloy wetted parts.

  In the invention according to claim 2, the wax is selected from low-polymerized polyolefin-based materials, fatty acid ester-based materials, fatty acid amide-based materials, ketones / amines, polyurethane resins, natural waxes, paraffin waxes, and microcrystalline waxes. It is the nickel elution prevention method of the copper alloy wetted parts containing 1 or more types.

  The invention according to claim 3 is a nickel elution preventing method for a copper alloy wetted device in which a wax is contained in an amount of 0.455 wt% or more with respect to the protective film forming agent.

  The invention according to claim 4 is a nickel elution prevention method for a copper alloy wetted device, wherein the solvent component is a component containing one of a water-soluble organic solvent and an alkaline solvent.

  The invention according to claim 5 is a nickel elution prevention method for a copper alloy wetted device in which an amine substance such as benzotriazole or tolyltriazole is contained in the protective film forming agent and an alkali solvent is contained in the solvent component.

  In the invention according to claim 6, a protective film is formed with the protective film forming agent on the surface of the nickel plating layer at the wetted part of the wetted device, and nickel elution due to contact corrosion of different metals is suppressed through the protective film. It is the nickel elution prevention method of the made copper alloy wetted parts.

  The invention which concerns on Claim 7 is the nickel elution prevention method of the copper alloy wetted device material which formed the protective film in the pinhole of the nickel plating layer with the protective film formation agent so that copper and nickel might be insulated.

  The invention according to claim 8 forms a protective film with a protective film forming agent on the surface of the nickel plating layer at the wetted part of the wetted device, and suppresses dissolution of the nickel plating itself due to the liquid contact through the protective film. It is the nickel elution prevention method of the made copper alloy wetted parts.

  The invention according to claim 9 is a copper alloy in which the protective film forming agent is applied to at least the wetted surface of the wetted equipment to form a protective film, and the nickel salt adhering to the inside of the wetted equipment is washed and removed. This is a nickel elution prevention method for wetted equipment.

  The invention according to claim 10 is the nickel elution prevention method according to claim 10, wherein the surface layer of the wetted part of the wetted device is deleaded and the nickel elution is prevented from being made of a copper alloy wetted device.

  According to an eleventh aspect of the present invention, there is provided at least one inorganic acid composed of nitric acid, sulfuric acid, borohydrofluoric acid, fluorosilicic acid, and metal sulfonic acid, and acetic acid, formic acid, acrylic acid, butyric acid, citric acid, and propion. Mixing a cleaning solution containing at least one of organic acids composed of an acid, both nickel salt adhering to the inside of the wetted equipment as a residue by this cleaning solution and lead segregated on the surface layer of the wetted part, or either This is a nickel elution prevention method for a copper alloy wetted device in which either one is washed away.

  The invention according to claim 12 is a mixture of nitric acid and a cleaning solution containing at least one of halogen acids consisting of hydrofluoric acid, hydrochloric acid, and hydrobromic acid. This is a nickel elution prevention method for a copper alloy wetted device in which either or both of the nickel salt adhering to the inside while preventing corrosion and lead segregated on the surface layer of the wetted part are washed away. .

  According to a thirteenth aspect of the present invention, there is provided a nickel alloy for wetted parts made of copper alloy comprising a protective film forming component containing at least a wax and a solvent component for dissolving the protective film forming component in water. It is a protective film forming agent for elution prevention.

  The invention according to claim 14 is a copper alloy wetted device that removes nickel salt adhering to the inside of the wetted device and suppresses removal of metallic nickel at the mouth of the wetted device. It is a cleaning agent for preventing nickel elution.

  Further, the protective film forming component may be dissolved in an organic solvent containing at least one selected from glycol ethers, alcohols, and amines so as to meet the DMG test based on the EN12471 standard. . Examples of glycol ethers include 3-methyl 3-methoxybutanol and butyl cellosolve, alcohols include benzyl alcohol, and amines include morpholine, monoethanolamine, triethanolamine, and triisopropanolamine. Examples include alkanolamines having a shape, amines having a cycloform such as cyclohexylamine and dicyclohexylamine, and long-chain alcoholamines.

  Examples of the organic solvent include 10% by weight of 3-methyl 3-methoxybutanol and 0.03% by weight or more of morpholine, and 10% by weight of 3-methyl 3-methoxybutanol and 0.02% by weight or more of monoethanolamine. Or those comprising 10% by weight of 3-methyl 3-methoxybutanol and 0.05% by weight or more of triethanolamine are preferred.

According to the first aspect of the present invention, even if nickel plating adheres to the wetted surface such as the mouth part of the copper alloy wetted parts subjected to plating, nickel is added to the supplied fluid such as tap water. The plating does not melt, and it is possible to provide safe and environmentally friendly copper alloy wetted parts. As the copper alloy wetted parts, water supply pipes, water supply equipment installed in the middle of the piping, for example, water supply valves, water supply hot water supply valves, pipe joints, strainers, etc., water supply equipment installed at the end of the water supply pipe, for example Faucets, water purifiers, water heaters, etc.
In addition, a protective film forming agent is used as a protective film forming component and a solvent component, and the protective film forming component, which is a main component in the protective film formation, is combined with various waxes and amine substances to provide high performance. This is a nickel elution prevention method capable of providing liquid equipment.

  According to the invention according to claim 2, nickel elution during nickel plating can be effectively prevented, and even when based on stricter standards, nickel elution can be suppressed correspondingly and excellent in safety. This is a nickel elution prevention method for copper alloy wetted parts that can be provided with copper alloy wetted parts.

  According to the invention of claim 3, the nickel elution prevention method for a copper alloy wetted device that can suppress the elution level of nickel to the utmost and can provide a wetted device compatible with a wetted part that requires high quality. It is.

  According to the invention according to claim 4, it is possible to select and combine an appropriate water-soluble organic solvent or alkali solvent for the type of wax or amine substance, and the performance and function of the protective film, formation time, cost, etc. This is a nickel elution prevention method for copper alloy wetted parts that can provide wetted parts of various properties according to all factors.

  According to the invention of claim 5, it is possible to obtain a wetted device that prevents nickel elution in response to more severe requirements such as nickel allergy, and only when nickel plating is applied to the copper alloy. Even when nickel plating treatment is applied to other metals, nickel elution prevention effect can be obtained. For example, even when a protective film is formed on pure nickel steel, excellent nickel that can pass strict evaluation tests This is a nickel elution prevention method for a copper alloy wetted device capable of exhibiting an elution prevention effect.

  According to the sixth aspect of the present invention, the protective film is formed on the surface of the wetted part and the nickel plating layer attached to the wetted part, so that the electrical contact between the wetted part (the wetted part) and the nickel plating is achieved. Conduction is prevented, and nickel elution due to contact corrosion of different metals is reliably prevented.

  According to the seventh aspect of the present invention, since the defect portion such as the pinhole of the nickel plating layer is filled with the protective film forming agent, nickel elution due to the contact corrosion of different metals is reliably prevented.

  According to the invention which concerns on Claim 8, melt | dissolution from nickel plating itself by contact with a fluid is suppressed by formation of a protective film. As a result, nickel elution is reliably prevented without being influenced by water quality factors such as pH, physicochemical factors such as changes in flow velocity and changes in water temperature.

  According to the inventions according to claims 9 to 12, in a wet alloy device made of copper alloy such as bronze or brass subjected to plating treatment including nickel, lead segregated on the surface layer of the wetted part and adhered to the inside as a residue Nickel salt can be removed reliably, and elution of nickel plating adhering to wetted parts such as the mouth can be prevented. Even if fluid such as tap water is supplied, these will not be eluted. According to the Ordinance of the Ministry of Health, Labor and Welfare regarding water quality standards, water supply equipment (valves etc.) installed in the middle of piping is 0.01 mg / l, and water supply equipment (water faucets etc.) installed at the end of pipes is 0.007 mg as a special value. On the other hand, for nickel, since the water quality management target setting item value of the Ministry of Health, Labor and Welfare is 0.01 mg / l for nickel, water supply tools (valves etc.) installed in the middle of piping are 0.0 A water supply tool (such as a faucet) installed at the end of a pipe at 1 mg / l can provide a nickel elution prevention method for copper alloy wetted parts that meet the leaching standard of 0.001 mg / l. In particular, the acid cleaning treatment using a cleaning solution to which nitric acid and hydrochloric acid as an inhibitor are added has an activation function as a pretreatment for forming a protective film, and an organic combination of the acid cleaning treatment and the protective film forming treatment. Is realized.

  According to the thirteenth aspect of the present invention, the liquid contact portion of the copper alloy wetted device that has been plated with nickel, and the surface of the nickel plating layer at the wetted portion are firmly bonded to the surface. In addition to the elution of nickel plating itself due to liquid contact, nickel elution due to contact corrosion with dissimilar metals is possible. It is possible to provide a protective film forming agent for preventing nickel elution that can be prevented.

  According to the invention which concerns on Claim 14, the nickel salt adhering to the inside of the said wet-contact equipment as a residue is removed, and the nickel elution prevention which can suppress the removal of the metallic nickel of the mouth part of the said wet-contact equipment It becomes possible to provide a cleaning agent.

  Furthermore, according to the present invention, a protective film forming agent dissolved in an organic solvent is made of copper alloy, nickel steel, nickel alloy, steel toys, stationery, etc., which are plated with nickel. It can also be applied to decorative products, food processing equipment, medical equipment, medical products, etc., and exhibits an excellent effect of preventing the development of nickel allergy caused by contact with these products / parts.

  An embodiment in which the nickel elution prevention method according to the present invention is applied to a wetted device made of bronze / brass will be described with reference to the drawings. The wetted equipment here refers to water supply pipes, water supply tools and their components installed in the middle of piping, such as water supply valves, water supply and hot water supply valves, pipe joints, strainers, and water supply equipment installed at the end of the water supply pipe Including tools and parts thereof, for example, faucets, water purifiers, water heaters, etc., or other finished products directly connected to water pipes and pipes.

  In the nickel elution prevention treatment according to the present invention, the copper alloy wetted parts (valve parts in this example) that have been processed after casting have a mesh shape so that they do not collide with each other during transport and are not damaged or scratched. It is good to arrange in a special container with heat and chemical resistance. By placing N parts of wetted parts such as bodies and bonnets in a dedicated container as a unit and performing the processing described later in units of one unit, the processing variation in each part is reduced and the quality is kept constant. can do. In addition, the component parts may be put together in a dedicated container and processed in units of one valve.

  Further, when arranging the workpieces, it is preferable to arrange the workpieces in a direction in which the bubbles are excluded above and to the sides so that there is no air pocket that becomes a portion where the bubbles stay in each workpiece. Since the shape of the wetted equipment is complex, when immersed in each treatment tank, it is applied to the entire wetted surface of the wetted equipment by applying rocking or ultrasonic stimulation to completely remove the slight remaining bubbles. It is recommended that the cleaning liquid come into contact. In this example, the wetted parts are kept in the dedicated container, and all the processes described later are performed. In addition, after the casting, an acid cleaning process, which will be described later, may be performed in a state of a finished product (in this example, a valve) composed of a plurality of parts that have been processed.

  Next, each step of the nickel elution prevention method in the present invention will be described. FIG. 8 is a flowchart showing an example of processing steps of the nickel elution prevention method according to the present invention. The degreasing step 10 is for removing cutting oil and rust preventive oil during processing. Insufficient degreasing is important because lead cannot be sufficiently removed in the lead removal step 13 described later. When the target product (in this example, the valve component) is very dirty, it is effective to provide the hot water washing step 9 before the degreasing step 10 to remove the deposits. An example of the degreasing process 10 is shown in Table 1. Among these, it is preferable to employ an alkali chelate detergent in order to prevent the influence of the chlorinated organic solvent on the environment and the increase in BOD due to the emulsion detergent.

  When an alkaline detergent is used in the degreasing process 10, it is often washed off in the water washing process 11 after the degreasing process 10. In addition, for example, the washing tank is provided with an ultrasonic vibration device, or a plurality of washing tanks are provided, and the final washing tank is a mixed acid of 7 wt% nitric acid and 0.7 wt% hydrochloric acid, and the alkaline detergent component brought in by the movement of the container 7 is completely removed. It may be neutralized and removed. In the neutralization step 12, by controlling the pH (hydrogen ion index) of the main tank provided for neutralization, a trace amount of alkali components remaining in the water washing step 11 can be reliably removed. In the case where the lead removal step 13 using a cleaning liquid composed of a mixed acid is performed after the summation step 12, it is effective to prevent the deterioration due to the neutralization of the acid and to surely promote the lead removal.

Next, the lead removal process 13 will be described. In the lead removal step 13 in this example, the wetted equipment is immersed in a treatment tank containing a cleaning liquid composed of nitric acid (concentration 0.5 wt% to 7 wt%) and hydrochloric acid (concentration 0.05 wt% to 0.7 wt%). The lead deposited on the surface layer of the wetted part is effectively removed. In particular, in the case of a material containing a large amount of lead, such as CAC406, since this step 13 is provided before the plating step 15, lead segregated on the copper surface layer in the region where plating is assumed is removed in advance. It is effective. The cleaning solution used in the lead removal step 13 of this example is composed of nitric acid and a mixed acid to which hydrochloric acid is added as an inhibitor. This cleaning solution uses a mixture of an acid such as nitric acid in tap water or pure water, Alternatively, a mixed acid in which nitric acid is mixed with hydrochloric acid having an inhibitory effect is mixed with tap water or pure water. In this case, since Cl ⁻ ions of hydrochloric acid erode lead while uniformly forming a film on the copper surface, the lead is eroded while maintaining a glossy surface. At this time, lead chloride and lead nitrate are formed in the lead portion, and both of these salts are soluble in the mixed acid, so that erosion continues.

The acid contained in the cleaning liquid will be described in detail. Generally, it is known that acid corrodes (oxidizes) lead. However, since lead easily forms an oxide film by reaction with acid, it causes continuous corrosion. It is hard to cause. However, lower organic acids such as nitric acid, hydrochloric acid, and acetic acid continuously corrode lead, and nitric acid (HNO ₃ ) exhibits the highest corrosion rate. On the other hand, although hydrochloric acid (HCl) has a slower corrosion rate of lead than nitric acid, it has a high compounding power with copper. Therefore, when pickled with a mixed acid with nitric acid, nitric acid and copper react chemically to produce copper oxide. Before forming (Cu ₂ O or CuO), a copper chloride (CuCl) film is formed on the surface of the wetted device, and a so-called inhibitory effect that suppresses corrosion of copper by nitric acid is exhibited. Therefore, the inclusion of hydrochloric acid eliminates the oxidation of copper on the surface of the wetted equipment, prevents the problem of discoloration to black, and maintains the gloss of the metal.

  In addition, ultrasonic erosion or rocking may be performed in the treatment tank to promote lead erosion. Explaining the action of accelerating the elution of lead by the ultrasonic cleaning or the swinging of the wetted parts, the ultrasonic cleaning is applied to various parts of the reaction in the cleaning liquid by applying ultrasonic waves to the wetted parts in the cleaning liquid. It has the effect of quickly removing lead compounds from the wetted equipment, and the rocking motion is to remove the lead compounds from the wetted equipment by shaking the wetted equipment itself in the cleaning liquid, or the air generated in the immersed equipment. There is an effect to eliminate the accumulation. In particular, by increasing the stirring of the liquid in the cleaning liquid, a compound with lead is formed and lead is easily eluted. This ultrasonic cleaning and rocking may be used in combination.

  The cleaning liquid in the lead removal process 13 of this example is not limited to the above, and may be an acid cleaning process other than the mixed acid described above, or an alkali cleaning process. Moreover, after performing a lead removal process simultaneously with plating, you may make it remove nickel in the nickel removal process 16 mentioned later. Of course, in the case of a material with a low lead content, this step 13 can be omitted, and both lead and nickel can be removed in a nickel removal step 16 described later.

  The plating step 15 is a known one, and in this example, a versatile electrolytic nickel chrome plating treatment is adopted, but of course, the present invention is not limited to this. For example, nickel plating, nickel alloy plating, etc. It is optional. The plating targeted in the present invention is not a special plating such as supercritical plating, but a plating applied to a commercially available water supply device such as a water tap or a valve.

  Here, the elution of nickel in the wetted parts subjected to the plating process including nickel will be described. For example, in nickel chrome plating, which is electroplating, a wetted part is immersed in a plating solution, and a chromium layer is formed on the outer surface of the wetted part facing the electrode by using nickel as a binder. On the other hand, the inner surface (wetted surface, etc.) of the wetted device is not opposed to the electrode, so that the plating layer is not formed. However, of the wetted surface, nickel plating is applied to the mouth portion A surrounded by the one-dot oblique line in FIG. It is attached. As shown in FIG. 2, the chrome plating 2a and the nickel plating 2b which is not in a multi-layer state exist at the mouth portion corresponding to the liquid contact surface 1a of the liquid contact device 1 to which the plating 2 is applied. This is because the nickel plating 2b goes around the inside of the mouth rather than the chromium plating 2a due to the difference in the current density range.

  As described above, as shown in FIG. 3, in a state where copper (a wetted part 1a), which is a metal having a high corrosion potential, and nickel (nickel plating 2b), which is a metal having a low corrosion potential, are in contact with each other, When a fluid such as water comes into contact with both of them, it becomes electrically conductive, and nickel having a low corrosion potential (nickel plating 2b) undergoes anodic polarization by copper having a high corrosion potential (wetted part 1a) to cause a corrosion reaction. Dissimilar metal contact corrosion occurs that promotes oxidative dissolution of the metal. Further, a large number of pinholes 2c exist in the nickel plating 2b layer, and some of them reach the copper surface that is the base of the nickel plating 2b layer. A fluid such as tap water having good electrical conductivity enters this, and contact with different metals also occurs at this site. Furthermore, the nickel plating 2b adhering to the liquid contact portion 1a is also eluted from the nickel plating itself by contacting the fluid.

  As shown in FIG. 4 to FIG. 6, the presence of a nickel component was confirmed as a result of analyzing the deep inside of the wetted device by EPMA (X-ray microanalyzer). This nickel component is not metal nickel by plating, but nickel salt (nickel sulfate, nickel chloride, nickel hydroxide) in the plating solution remains inside the wetted parts after plating, and dries and adheres to the inner surface. is there. Valves, pipe joints, strainers, faucet fittings or other water supply devices having complicated flow paths are formed by sand casting using a copper alloy material. The casting surface thus cast has a lot of irregularities, and the lead moved from the grain boundary to the surface layer during solidification is segregated in the indented portion. In particular, the inner surface layer of a water supply device that is not subjected to surface processing is prominent, and if plating is performed in that state, the plating solution remains on the lead in the recesses and dries, which is different from metallic nickel. It is thought that salt adheres. Since water supply equipment such as a faucet fitting has a complicated flow path, it is difficult to remove the plating solution remaining inside, and it is considered that the adhesion of the nickel salt becomes remarkable. In this state, when a fluid such as tap water is supplied to the water supply device, lead and nickel salts are eluted. It should be noted that the indented portion as described above is liable to be formed even when a so-called hot water wrinkle is produced during casting, particularly on the wetted surface such as a mixing plug having a complicated shape, and the nickel salt is liable to adhere.

Next, the nickel removal step 16 (surface activation treatment) will be described.
Here, in general, the plating applied to the copper alloy wetted parts is mostly nickel chrome plating. At this time, the nickel plating acts as a base plating for improving the chrome plating, and at the same time, a soft copper alloy substrate. Since the film has a purpose of preventing exposure due to scratches or the like, the film thickness is as thick as several μm to several tens of μm, and the nickel plating has spread to the inner surface of the wetted device material to which chrome plating is difficult to adhere. Nickel chrome plating applied to wetted parts is mainly required for fluid sealing function such as ball valve balls, which are parts of wetted parts, and decorativeness such as faucet fittings. There are uses.
Therefore, in the nickel removal step, the chemical solution used for the surface activation treatment should not invade chrome plating and must not impair the decorative properties of plating such as discoloration.

  Nickel is a metal rich in corrosion resistance and has corrosion resistance against various types of acids. On the other hand, since chromium plating has corrosion resistance by the chromium oxide passive film on the plating surface, it is not possible to use a treatment component that affects the passive film. For this reason, in this example, as the nickel salt removal component, a mixed acid composed of an inorganic acid or an organic acid is used as the treatment liquid.

The inorganic acid includes at least one of nitric acid, sulfuric acid, borohydrofluoric acid, fluorosilicic acid, and methanesulfonic acid.
The organic acid contains at least one of acetic acid, oxalic acid, formic acid, acrylic acid, butyric acid, citric acid, and propionic acid, and the wetted equipment 1 is placed in the treatment tank containing the treatment liquid. The nickel salt adhering to the inside as a residue is removed. Here, the inorganic acid having an acid dissociation degree of about 1 does not need to be increased in concentration, and can be used at a low concentration. On the other hand, the organic acid needs to be used at a high concentration because the degree of dissociation is small.

Among these, in particular, in the case of a cleaning solution in which nitric acid and hydrochloric acid as an inhibitor are added, nitric acid acts on nickel, and nickel salt can be effectively removed from the surface layer of the wetted part in the state of nickel nitrate. Care must be taken when nitric acid is selected as the inorganic acid. In other words, the inner surface of a copper alloy wetted device is a copper alloy substrate, and the components that discolor or corrode the inner surface are not suitable as cleaning fluids, but when nitric acid is used alone, the copper alloy is blackened. May cause discoloration.
For this reason, when nitric acid is used as the treatment liquid, a mixed acid with a halogen acid (hydrofluoric acid, hydrochloric acid, and hydrobromic acid) may be used. In this case, the nitric acid concentration range is 67% nitric acid 0.5-7 wt% in JIS K8541, and the halogen acid concentration range is 46% hydrofluoric acid 0.05-0.7 wt% in JIS K8819, or JIS K8180, 36% hydrochloric acid 0.05 to 0.7 wt%, or JIS K8509 48% hydrobromic acid 0.05 to 0.7 wt%.

This cleaning liquid also acts on nickel adhering to the mouth portion of the water supply device, and has a function of activating the nickel surface as a pretreatment for forming a protective film, which will be described later. Bonding is strengthened.
Here, the metal surface generally has some gas or organic molecules adsorbed on the surface, and the metal element is not present in the atmosphere in an exposed state. There are various types and thicknesses of components that are adsorbed to such metals, but for example, metals such as chromium and aluminum are stable between adsorbed oxygen and gas bodies and organic molecules even if adsorbed on the surface. Thus, a uniform transparent oxide film is formed, and the metallic luster can be visually observed. In addition, these metals are also referred to as non-moving films, because even when the surface appears due to scratches or the like, they are relatively easily repaired due to the strong bond with oxygen.

  On the other hand, nickel is a metal with high corrosion resistance, but has a dull metallic luster because a stable transparent oxide film is not formed with oxygen unlike chromium and aluminum. This is also due to the fact that the substances adsorbed on the nickel surface are present in a random manner and the light source is irregularly reflected. The substance adsorbed on the metal surface of nickel is not strongly bonded to nickel, but mechanically or chemically like a part that forms a compound with nickel on the metal surface such as so-called rust. There is no need to remove it.

If organic molecules and gas bodies adhere to the metal, they can be removed by surface activation treatment. However, in the atmosphere, the metal is stabilized by the innumerable free electrons existing on the surface combined with the gas body. It becomes easy to become the state. As a result, in the protective film forming process described later, the protective film forming agent is bonded to nickel to form a protective film, and has a side chain bonded to the metal, but the gas body is bonded to the nickel surface and is stable. When it is in a converted state, this protective film forming agent becomes difficult to bind.
For this reason, in the nickel removal step, the surface of the nickel is activated by activating the surface, and then the surface of the surface is rich in bonding properties through a water washing step. And the protective film forming agent can be strengthened. The organic molecules can be removed even by performing alkaline degreasing by an alkaline degreasing process.

  Thus, in the nickel elution prevention method shown in this example, the acid cleaning treatment and the protective film formation treatment described later are organically combined. At this time, if the component concentration of the cleaning liquid, particularly the nitric acid concentration is low, the removal of the nickel salt from the inside of the water supply device becomes insufficient, or the activation of the nickel surface attached to the mouth portion of the water supply device becomes insufficient. . On the other hand, if it is too dark, it may affect the luster or the like of nickel plating applied to the outer surface of the water supply device to be treated. For example, when hydrochloric acid is used as the inorganic acid and hydrochloric acid is used as the organic acid, the preferred component concentrations in the acid cleaning treatment of this example are nitric acid 0.5 wt% to 7 wt%, hydrochloric acid 0.05 wt% to 0.00. It is good to set it as 7 wt%.

  In addition, as a precaution for the acid used for the surface activation treatment, the nickel chromium plating component nickel and chromium should not be attacked, and the copper alloy substrate should not be discolored. If so, most are applicable. However, in any of the organic acids described above, the degree of acid dissociation is low, and it is necessary to use it in a state in which the concentration is increased. This leads to an increase in cost, and the acid odor becomes intense, resulting in poor work efficiency.

  Further, since the inorganic acid has a high degree of dissociation, sulfuric acid that is a non-oxidizing acid functions sufficiently as a surface activation treatment liquid even at a concentration of about 5 to 10 wt%. However, sulfuric acid is a highly viscous acid, and it can be said that it is difficult to handle because it involves a strong exothermic reaction when used diluted with water. Nitric acid, which is oxidizing, is most preferable from the standpoint of easy handling as an inorganic acid, beautification of the plating appearance, and protection of the chromium plating passive film on the plating surface layer. However, as described above, this nitric acid changes the color of the copper alloy to black. There is a risk of causing.

Therefore, the surface activation treatment solution is most preferably a solution in which a halogen acid having a concentration of 0.1 wt% is added to nitric acid to prevent discoloration of the copper alloy, whereby the negative ion portion is F ⁻ , Cl. ^-, Br ^- and one element halogen acids comprised of is smaller than nitrate ion atomic group, also made it possible to exert excellent inhibitor effects bound to quickly copper alloy surface becomes stronger ionic forces Yes.

  Further, when the lead removal step 13 is omitted, such as when targeting a material with a low content of lead, lead and nickel are removed in this step 16. The cleaning liquid may be, for example, a mixture of nitric acid and a mixed acid to which hydrochloric acid is added as an inhibitor. In the case shown in FIG. 7, the nitric acid first acts on nickel, and the wetted part is in the state of nickel nitrate. The nickel salt is removed from the surface layer, and then immediately acts on the lead existing under the nickel salt to remove it. Therefore, in this case, lead and nickel are simultaneously removed by one acid cleaning treatment. Note that the cleaning liquid used in the nickel removal step 16 has been described in detail in the lead removal step 13, and therefore the description thereof is omitted. Further, since nickel is a corrosion-resistant material against alkali and sulfuric acid such as sodium hydroxide, for example, these liquids cannot remove nickel regardless of the concentration and temperature.

  Next, a description will be given of a preferable treatment temperature and a treatment time in the present step 16 in which the lead removal step 13 or the lead removal step 13 is omitted, or in the present step 16. The preferred treatment temperature x is a temperature range of 10 ° C. ≦ x ≦ 50 ° C. The room temperature range is preferable. The normal temperature range refers to a range in which the temperature in which the cleaning liquid is neither heated nor cooled can be taken, and refers to a temperature range that can vary depending on the temperature of the wetted equipment to be processed and the atmosphere outside the processing tank. Specifically, it is in the range of 10 ° C. to 30 ° C., in particular, 15 ° C. to 30 ° C. is preferable, and 25 ° C. is optimal. A preferable processing time y is 5 minutes ≦ y ≦ 30 minutes.

  When the processing temperature exceeds 50 ° C., bubbles due to boiling start to stand out in the cleaning liquid, air pockets are likely to be generated in the wetted equipment that is the object to be processed, and a portion where the cleaning liquid does not come into contact with the surface of the wetted equipment is generated. . In addition, the evaporation of water and acid becomes intense, making it difficult to manage the concentration of the cleaning liquid and the like, and the environment of the treatment work is deteriorated due to the evaporation of the acid. On the other hand, if the processing temperature falls below 10 ° C during processing in winter, etc., if the wetted liquid equipment enters the processing tank, the cleaning liquid may drop to near 0 ° C and freeze. The temperature at which the cleaning liquid is not likely to freeze even after mass production is set to 10 ° C. or higher. In addition, when the processing time exceeds 30 minutes, the efficiency of lead removal does not increase so much even if the processing time is taken, and the processing time is too long and is not suitable for mass production processing. On the other hand, if the treatment time is less than 5 minutes, the treatment temperature is set to 5 minutes or more because it is insufficient for preventing lead elution even if the treatment temperature is raised. Of course, it is not limited to this.

  In addition, it is possible to handle existing wetted parts. In this case, for example, in the case of a valve, since parts other than metal such as packing and gasket are immersed in the cleaning liquid, the deterioration of the part depends on the cleaning time, temperature, and concentration. In that case, a chemical resistant material such as fluoro rubber may be used. In this example, hydrochloric acid is used as an inhibitor in the cleaning solution for the acid cleaning treatment. However, an organic acid such as acetic acid or sulfamic acid is used as a mixed acid with nitric acid to remove lead and nickel. Good.

  Here, the leaching test of nickel and lead after application of the present invention is performed, and the test results will be described. When the acid washing process as a nickel removal process was performed using the sample of the nickel leaching source specific test described above, it was confirmed that most of the nickel salt adhering to the residue inside the water supply apparatus was removed. The acid cleaning in this leaching test is performed with a mixed acid of 4 wt% nitric acid + 0.4 wt% hydrochloric acid, and the test results are shown in Table 2 (Ni, Pb leaching amount after acid cleaning treatment (mg / l)). As shown in the table, the leaching amount of Ni (correction value as a pipe end device) satisfies the leaching standard of 0.001 mg / l, and the leaching amount of Pb (same correction value) is also 0.007 mg. / L leaching criteria were met.

  After the nickel removing step 16, the water is quickly washed in the water washing step 17 so that the washing liquid is removed from the surface of the wetted equipment.

Next, a protective film forming process is performed in a protective film forming step 18. The protective film forming agent used in the protective film forming step 18 includes at least a protective film forming component containing wax and a solvent component for dissolving the protective film forming component in water.
The wax is one of a low-polymerized polyolefin material, a fatty acid ester material, a fatty acid amide material, a ketone / amine, a polyurethane resin, a natural wax, a paraffin wax, and a microcrystalline wax, and more specifically Is preferably a low-polymerized polyethylene in a low-polymerized olefin system.
Further, the wax is preferably contained in an amount of 0.455 wt% or more based on the protective film forming agent.

  Next, the solvent component combined with these protective film forming components contains at least one of a water-soluble organic solvent and an alkaline solvent, and the main components thereof are workability, environmental properties, Water is preferred for reasons such as enhancing safety (non-flammability). As this water, softened water, tap water, or industrial water can be used, but the pH needs to be neutral, and it is necessary to avoid alkali ion water or acid ion water.

  The water-soluble organic solvent is characterized by being easily mixed with water and easily dissolving the amine substance. For this reason, it is applied as a component to be combined when an amine substance that is hardly soluble in water is used as a protective film forming component. Thus, a protective film forming agent containing an amine substance as a protective film forming component and a water-soluble organic solvent as a solvent component is formed. In this case, the water-soluble organic solvent is a lower alcohol (for example, methanol, ethanol, propanol, benzyl alcohol, butanol) or glycol (for example, glycol ether (for example, 3 It is preferable to apply polar organic solvents such as methyl 3-methoxybutanol, butyl cellosolve, etc.), ethylene glycol, ethylene glycol), lower ketones (for example, acetone, diethyl ketone).

The alkaline solvent which is one of the solvent components needs to be easily mixed with water and easily dissolve the protective film forming component. Examples of the alkaline solvent include morpholine, which is a cyclic amine, and sodium hydroxide as a hydroxide.
Moreover, since the entire protective film forming agent can be kept alkaline by using an alkaline solvent as a solvent component, it is possible to prevent the protective film forming agent from being spoiled by various bacteria.

  Next, a protective film forming component comprising a wax and an amine substance will be described. Protective film forming agent consisting of wax and amine substance can exert higher nickel elution suppression effect, can surely prevent nickel allergy, and protect against metals other than copper alloy, such as pure nickel steel Even when the film is formed, the effect of preventing elution of nickel can be exhibited as in the case of the copper alloy. In this case, the protective film forming component is preferably a component having nitrogen for bonding with nickel in nickel plating, and a component having hydrocarbon is preferable for forming a film having water repellency.

  The component satisfying these conditions is an amine substance, and among these, the primary amine and secondary amine in which nitrogen is bonded to hydrogen can be bonded to nickel. Furthermore, considering the case where warm water flows through the wetted equipment that has been plated with nickel, the protective film forming component has a high melting point (eg, 50 ° C. or higher) and a stable structure is preferable. More preferably, it contains an amine substance, particularly a secondary amine having a cyclic structure (hereinafter referred to as “cyclic amine”). Even in the case of a compound having a cyclic structure, elements other than nitrogen, for example, furans and thiophenes containing oxygen, sulfur, and the like cannot be combined with nickel and are excluded.

  In this embodiment, benzotriazole or tolyltriazole is used as the amine substance, and a greater effect is exhibited. In particular, when benzotriazole is used as the protective film forming agent, excellent bonding strength with nickel can be achieved. Benzotriazole bonds to the plating surface with the benzene ring having the effect of repelling water (water repellency) facing outward and the hydrophilic group facing inside (plating side). For this reason, as a result of realizing close coupling with the nickel plating, it is possible to form a strong protective film.

  One protective film forming agent component, low-polymerized polyethylene, is an elongated molecule and a neutral substance as compared with an organic acid such as oleic acid. When a protective film is formed using this low-polymerized polyethylene, it does not stand up on the nickel substrate and is in a state of being roped as shown in FIG. The thin rope of this low polymerized polyethylene is stretched vertically and horizontally to form the base, and the cellular part between the eyes is regularly packed with benzotriazole and benzotriazole derivatives like meteorites. Become. Accordingly, the bond between the protective film forming agent and nickel is further strengthened in combination with the activation by the acid cleaning treatment. Examples of benzotriazole derivatives include tolyltriazole and carboxybenzotriazole. The structure of benzotriazole is shown.

In order to obtain a regular state as shown in FIG. 11, the liquid state as the protective film forming agent is stable, and the triazole-based substance in the protective film forming agent is more uniformly dissolved to form a protective film. There is. This will be described in detail below.
In paraffinic hydrocarbons such as low-polymerized polyethylene, there are some molecules that have hydrophilic substituents such as hydroxyl groups, carbonyl groups, and carboxyl groups with oxygen at the molecular end due to the effects of heat, ultraviolet rays, and oxygen. To do. Naturally, paraffinic hydrocarbons are non-polar, but if they have these substituents, they are slightly polar. On the other hand, water is usually a substance that hardly ionizes, but the addition of an electrolyte such as sodium hydroxide increases the electrical conductivity of the water. In addition, in water where alkaline substances such as sodium hydroxide are present, the molecular terminal where the hydrophilic substituent exists is directed to the water side, and the hydrophobic side of the low polymer resin part is directed to the opposite side. Sex appears. Due to such a molecule, regularity also appears in a molecule having no hydrophilic substituent at the molecular end, and macroscopically, it can exist in water in a state where the emulsification is stable. When a film is formed on Ni, a cellular wall is formed while maintaining this regularity, and the protective film is formed by clogging benzotriazole in the cell.

  And when forming a film on nickel, even if air blow is carried out after the protective film forming process or moisture is removed by a drying process, the protective film is maintained with a certain degree of regularity as described above. And a film that exhibits a function also in the DMG test of EN12471 standard can be formed.

  In this way, by including an alkaline solvent, a wetted device that has improved the nickel elution prevention effect in response to nickel allergy, and a contact film that has formed a protective film while enhancing the nickel elution prevention effect on metals other than copper alloys. Liquid equipment can be obtained.

  Here, the EN 12471 standard of the European Council Directive94 / 27 / EC directive of EU as a method for judging the degree of nickel removal for nickel allergy countermeasures will be described. This standard uses a mechanism that forms a red reactant when nickel ions encounter DMG (dimethylglyme oxime) in the presence of ammonia. In this test using DMG, two drops of ethanol solution in which DMG is dissolved and two drops of ammonia solution are dropped on a cotton swab, and when the test piece (sample) is rubbed with the swab, it is caused by physical contact of the swab. The degree of nickel removal can be determined by checking the degree of peeling.

In order for the protective film-forming agent to withstand the physical contact of the cotton swab by the DMG test, the weakly alkaline substance and the weakly alkaline benzotriazole or tolyltriazole (benzotriazole derivative), which is a component, are important. Since the acid with a high degree of dissociation that reacts inhibits this bonding, the entire protective film must be kept alkaline. At this time, when the low polymerized polyethylene is used as the protective film forming agent component of the nickel elution preventing method in the present invention, since the low polymerized polyethylene is a neutral substance, an alkaline substance having a high degree of dissociation can be used. Therefore, it is possible to add a hydroxide composed of an alkali metal (lithium, sodium, potassium) or an alkaline earth metal (magnesium, calcium) as a solvent component. Further, as a pH adjusting agent, a water-soluble amine compound can be used in the same manner as alkali metals and alkaline earth metals.
This point is different from the characteristics of the protective film forming agent containing oleic acid. Because oleic acid is a weak acid, if you select them as alkaline solvents, they will react chemically. This is because the function of the protective film forming agent cannot be performed.

  With such characteristics, in FIG. 9, it is possible to provide a neutralization alkali treatment step 21 before the protective film formation step 18 to reduce liquid management of the film forming agent. Specifically, the neutralized alkali treatment step 21 is completely provided before the protective film formation step (film treatment step) 18 with respect to the mixed acid expected to be mixed from the nickel removal step (mixed acid treatment step) 16. It can be removed. In this case, the neutralizing alkali agent is preferably the same as the alkali component element in the film forming agent and having the same concentration. In this way, by performing management so as to maintain the alkalinity of the main tank, the pH is controlled in the liquid management of the protective film forming agent when the protective film forming component is an amine substance and the solvent component contains an alkaline solvent. It is sufficient to manage only the concentration without necessity, and the risk of deterioration of the protective film forming agent due to mixing of the mixed acid component can be almost eliminated. Furthermore, since the neutralization alkali treatment process 21 has a short treatment time of, for example, 1 minute, it is more suitable for mass production than using the faucet process 17 (for example, a treatment time of 10 minutes) as shown in FIG. Yes.

  In addition, since the function of the protective film forming agent not containing an alkali solvent is lowered by use, the alkali management in the neutralization alkali treatment step 21 is to control the pH, and this management is further performed to determine the remaining alkali components. Desirably, the neutralization titration method can be controlled. Thereby, the alkalinity of the process liquid in the neutralization alkali treatment process 21 can always be maintained. In addition, in order to further suppress the alkali component in the protective film forming agent from being diluted by the carry-in liquid from the neutralized alkali treatment process tank, the faucet process 17 as shown in FIG. For example, it may be added as a process with a processing time of 1 minute.

  When forming the protective film, as shown in FIG. 10, a protective film 20 is formed on at least the liquid contact surface 1a of the liquid contact device 1 immersed in the protective film forming agent. Thereby, the protective film 20 is formed on the surface of the nickel plating 2b layer adhering to the wetted part 1a, and this protective film forming agent enters the minute pinhole 2c of the nickel plating 2b layer. Therefore, the wetted part 1a and the nickel plating 2b adhering to the wetted part 1a are insulated to prevent nickel elution due to contact corrosion of different metals, and also prevent nickel elution from the nickel plating 2b itself due to wetted liquid.

  The protective film by the protective film forming agent is formed not only on the liquid contact part at the mouth of the water supply device but also on the liquid contact surface inside. Therefore, the lead segregated on the surface layer of the liquid contact portion in the lead removal step 13 is removed, and a protective film is also formed on the internal liquid contact surface from which the nickel salt has been removed in the nickel removal step 16.

  In the protective film forming step 18, when a protective film is formed with a protective film forming agent containing a wax and a protective film forming agent containing a solvent component containing either a water-soluble organic solvent or an alkaline solvent. For example, even when an evaluation test according to JIS S3200-7 is performed, deterioration due to components contained in the simulated tap water used in the test is prevented, and also during test work such as water flow work and cleaning work Deterioration due to physical influence is prevented, and an excellent nickel elution prevention function can be exhibited.

  As shown in FIG. 8, after the protective film forming step 18, the film is dried in a drying step 19. By this drying step 19, the moisture contained in the protective film forming agent evaporates, and the protective film made of wax or amine substance is fixed to the surface of the copper alloy or nickel plating layer. In particular, the organic combination of the acid cleaning process and the protective film forming process exerts a synergistic function by the above-described cleaning liquid, and the product / member formed with the protective film in the protective film forming step 18 has extremely excellent nickel elution. Preventive effect is shown. The container that has passed through all the processes is transported to the assembly process, and the wetted equipment (valve parts in this example) is taken out from the container and assembled and inspected.

  In this example, environmental issues and waste liquid treatment costs are also taken into consideration. As described above, an alkaline detergent is used in the degreasing process 10 of this example, and nitric acid (concentration 0.5 wt% to 7 wt%) and hydrochloric acid (concentration 0.05 wt%) in the lead removal process 13 and nickel removal process 16 of this example. As shown in FIG. 8, both the alkaline detergent soiled in the degreasing process 10 and the mixed acid solution containing heavy metals in the lead removing process 13 and the nickel removing process 16 are used. This is because the reaction can be neutralized to remove precipitates and suspended solids as solids, and the oil can be separated for industrial waste treatment. Thereafter, the neutralized water which has become harmless can be used as industrial water. Further, as shown in the figure, the diluted alkaline waste liquid discharged from the water washing step 11 after the degreasing step 10 and the water washing step 14 after the lead removal step 13 and the water washing step 17 after the nickel removal step 16 are discharged. It can be neutralized by mixing with dilute acidic waste liquid, removing precipitates and suspended solids as solids, and separating oil for industrial waste treatment. Thereafter, the neutralized water which has become harmless can be used as industrial water.

  Furthermore, the protective film forming process in the present invention can be performed on an existing assembled product such as a valve or a faucet that has not undergone the nickel removal process. In this case, after the assembled product is degreased, it is protected. A film forming process is performed. Since the protective film forming agent of the present invention is not corrosive and there is no possibility of deteriorating non-metallic packing or gaskets incorporated in valves, faucets and the like, it can be applied to finished products. In addition, the protective film is formed by immersing the wetted parts and the finished product to be treated in the protective film forming agent. A spraying process such as spraying may be employed.

  Examples to which the nickel elution prevention method according to the present invention is applied will be described in detail. Flushing metal fittings that are actually subject to plating treatment vary in shape, and the characteristics of plating differ depending on the operator, so nickel that has wrapped around the mouth of the metal fitting that is likely to actually affect nickel leaching. A test was performed using a test piece (sample) for plating, and the conditions were compared in a common state. The sample used for the test is shown in FIG. The test piece was pierced for plating, and the surrounding area was covered with vinyl tape to make the installation area constant.

As a condition of plating applied to the sample, the base material is CAC406, and in order to reproduce an incomplete plating state on the milled surface of this CAC406, electrolytic nickel having a thickness of 2 to 3 μm is used. As for the surface area of the sample in FIG. 12, the area of the plate surface is 30 (mm) × 40 (mm) × both sides (two sides) = 2400 (mm ² ), and the formed holes also require a plating step. Therefore, the surface area of this hole was measured. The surface area of the hole is hole diameter 5 (mm) × plate thickness 5 (mm) × circumferential ratio (≈3.14) = 78.5 (mm ² ). The total is 2478.5 mm ² .

The evaluation method of each test piece was performed by JIS S3200-7 part test, and after immersion for 16 hours in the exudate, the exudate was analyzed by ICP (inductively coupled plasma). At this time, two samples were placed in a beaker containing a constant leachate and immersed. The amount of leachate at the time of this test was 160 mL, and the wetted area was about 5000 mm ² (since there were ^two samples with a surface area of 2478.5 mm ² ), which is the general water tap capacity (155 mL) and wetted area It was set with reference to (3000 mm ² ).

  As the surface treatment method for the samples, the surface treatment was performed on each of the samples 1 to 5 using the treatment step shown in FIG. 13 and the protective film forming agent in Table 3. The test results are shown in Table 3.

  From the results in Table 3, it can be determined that the low polymerization polyethylene is at a level that clears the JIS S3200-7 leaching test when the content is 0.455 wt% or more.

  Then, the test for providing the protective film formation agent which can be plated to the metal other than the plating alloy corresponding to nickel allergy, or a copper alloy was done. Even when the low-polymerized polyethylene in the sample 3 is 0.455 wt% as a result of the test performed in Example 1, when the metal to be plated is pure nickel steel, the DMG of EN12471 standard is used. This is because the test could not be cleared, and components of a protective film forming agent applicable to these uses were obtained.

Samples 6 to 11 in this test were formed under the same conditions as in Example 1, and further, the base material made of pure nickel was prepared under the same conditions. The surface treatment of FIG. 13 was performed on this sample, and a DMG test was performed on this. Here, the DMG test based on the EN12471 standard is subjected to pretreatment and heating (50 ° C.) for simulating the effect of sweat and corroding the surface with artificial sweat, and then nickel ions are dimethylglyoxime in the presence of ammonia. It is based on the point that when it meets, it forms a red reaction. These indicator substances are soaked in cotton swabs, and the color change is observed while the target substance is strongly worn, and it is assumed that we will directly touch the nickel-containing substance. Since slight discoloration is judged to have exceeded 0.0005 mg / cm ² / week, only no discoloration is accepted. In addition, since the protective film was soluble in ethanol at the time of a test, it implemented after vaporizing ethanol well. The test results are shown in Table 4.

  Furthermore, tests were performed in the same manner as described above using tolyltriazole (benzotriazole having a methyl group), which is a benzotriazole dielectric, and the results in the following table were obtained.

  The reason why the DMG test results of Sample 6 in Table 4 and Sample 9 in Table 7 were unacceptable was that there was no alkaline component to keep alkaline and the connecting portion effective for bonding was unstable. . The low-polymerized polyethylene in the present invention does not react with an alkali component, and therefore, plating that can pass the DMG test when sodium hydroxide is used as an alkaline solvent as in Sample 7 in Table 4 and Sample 10 in Table 5. A layer can be formed. In addition to sodium hydroxide, a strong alkali agent such as potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, titanium hydroxide, sodium hydroxide is used as the alkaline solvent. It is possible.

  Furthermore, if the nickel elution prevention method according to the present invention is applied to a copper base alloy having excellent corrosion resistance, hot workability, and stress corrosion cracking resistance properties, the copper alloy wetted liquid that prevents nickel elution in addition to the respective characteristics Equipment can be provided. Further, by using a lead-less copper-based alloy, it is possible to provide a copper-based alloy with extremely little lead elution. In this case, in the treatment process of the nickel elution prevention method shown in FIG. 8, the neutralization process 12, the lead removal process 13, and the water washing process 14 can be omitted, and after plating containing nickel in the plating process 15, By passing through the nickel removing step 16 and the protective film forming step 18, it is possible to provide a copper alloy wetted device that prevents the elution of lead and nickel.

  According to the present invention, a protective film forming agent dissolved in an organic solvent is made of copper alloy, nickel steel, nickel alloy, steel, etc., plated with nickel, a ring, a necklace, Accessories such as earrings, earrings, watches (bands), glasses (frames), toys such as minicars and dolls, stationery such as pencil cases and clips, medical equipment such as scalpels and injection needles, welfare care equipment such as wheelchairs and crutches, etc. It can be applied to decorative products, food processing equipment, medical products, etc. to prevent the development of nickel allergy caused by contact with these products / parts.

  The nickel elution prevention method, the nickel elution prevention protective film forming agent and the nickel elution prevention cleaning agent according to the present invention are made of stainless steel, nickel alloy, steel, including copper alloy wetted parts such as bronze and brass. It can be applied to various products and parts made of other materials such as manufactured products, and it is widely used in various fields as a treatment method that can prevent nickel elution and also lead elution. It is possible to provide.

It is sectional drawing of the JIS side water faucet (product made from CAC406) to which the nickel chromium plating process was performed. It is a partial expanded sectional view of the mouth part A shown in FIG. It is the B section expanded sectional view of FIG. It is the photograph which showed nickel distribution by EPMA (X-ray microanalyzer) of the inner surface of the JIS horizontal faucet (product made from CAC406) to which nickel chrome plating processing was performed. It is the photograph which showed the lead distribution by EPMA (X-ray microanalyzer) of the inner surface of the JIS horizontal faucet (product made from CAC406) to which the nickel chromium plating process was performed. It is an electron micrograph of the inner surface of a JIS horizontal water faucet (manufactured by CAC406) that has been subjected to nickel chrome plating. It is explanatory drawing which showed the presence condition of the lead and nickel in the crystal grain boundary of the liquid-contacting instrument material inner surface in which the process of nickel plating etc. was performed. It is the flowchart which showed an example of the process of the nickel elution prevention method in this invention. It is the flowchart which showed the other example of the process process of the nickel elution prevention method in this invention. It is sectional explanatory drawing which showed the state of the liquid-contact part surface layer after passing through the protective film formation process in this invention. It is explanatory drawing which showed the protective film formation state by the protective film formation agent containing low polymerization polyethylene and a benzotriazole. (A) is explanatory drawing which shows the structure at the time of seeing a protective film from a plane. (B) is explanatory drawing which shows the structure at the time of seeing a protective film in cross section. It is an external view of a test piece. It is the flowchart which showed the process process to a sample. It is explanatory drawing which showed the condition in the crystal grain boundary of the liquid-contact equipment inner surface in which the lead elution prevention process by the prior art was performed.

Explanation of symbols

1 Copper alloy wetted parts 1a Wetted parts (wetted part, wetted surface)
2 Plating 2a Chrome Plating 2b Nickel Plating 2c Pinhole 5 Lead 6 Nickel Salt 13 Lead Removal Process 15 Plating Process 16 Nickel Removal Process 18 Protective Film Forming Process 20 Protective Film 20a Protective Film (Benzotriazole)
20b Protective film (organic acid)

Claims (14)

  In the method for preventing elution of nickel in which a copper alloy wetted device is plated with nickel, at least on the wetted surface of the wetted device, a protective film forming component containing wax and the protective film forming component in water A protective film forming agent containing a solvent component to be dissolved is applied to form a protective film, and this protective film suppresses nickel elution, preventing nickel from elution of copper alloy wetted parts Method.   The wax includes at least one selected from low polymerized polyolefin materials, fatty acid ester materials, fatty acid amide materials, ketones / amines, polyurethane resins, natural waxes, paraffin waxes, and microcrystalline waxes. The method for preventing nickel elution of a copper alloy wetted device according to 1.   The method for preventing elution of nickel from a copper alloy wetted device according to claim 1 or 2, wherein the wax is contained in an amount of 0.455 wt% or more based on the protective film forming agent.   The method for preventing nickel elution of a copper alloy wetted device according to any one of claims 1 to 3, wherein the solvent component is a component containing one of a water-soluble organic solvent and an alkaline solvent.   4. The copper alloy wetted device according to claim 1, wherein the protective film forming agent contains an amine substance such as benzotriazole or tolyltriazole, and the solvent component contains an alkaline solvent. 5. Nickel elution prevention method.   The surface of the nickel plating layer of the wetted part of the wetted equipment is formed with a protective film with the protective film forming agent, and nickel elution due to contact corrosion of different metals is suppressed through the protective film. 6. The method for preventing nickel elution of a wetted equipment made of copper alloy according to any one of 5 above.   The method for preventing nickel elution of a copper alloy wetted device according to claim 6, wherein a protective film is formed in the pinhole of the nickel plating layer with the protective film forming agent so as to insulate copper and nickel.   2. The protective film is formed on the surface of the nickel plating layer at the wetted part of the wetted device with the protective film forming agent, and dissolution of the nickel plating itself due to the wetted liquid is suppressed through the protective film. The nickel elution prevention method of the copper alloy wetted parts according to any one of 1 to 5.   The protective film forming agent is applied to at least the liquid contact surface of the liquid contact device to form a protective film, and nickel salt adhering to the inside of the liquid contact device is cleaned and removed. The nickel elution prevention method of the copper-alloy wetted parts material of description.   9. The nickel elution prevention method according to claim 8, wherein the liquid contact surface of the liquid contact device is deleaded and the copper alloy wet contact device is deleached.   At least one of inorganic acids composed of nitric acid, sulfuric acid, borofluoric acid, fluorosilicic acid, and metal sulfonic acid, and at least among organic acids composed of acetic acid, formic acid, acrylic acid, butyric acid, citric acid, and propionic acid A cleaning liquid containing at least one kind is mixed, and this cleaning liquid cleans and removes nickel salt adhering to the inside of the wetted parts and / or lead segregated on the surface layer of the wetted part. The method for preventing nickel elution from a copper alloy wetted device according to claim 9 or 10.   A cleaning solution containing at least one of nitric acid and a halogen acid composed of hydrofluoric acid, hydrochloric acid, and hydrobromic acid is mixed, and the cleaning solution prevents residues and discoloration of the wetted parts. 11. The method for preventing nickel elution of a copper alloy wetted device according to claim 9 or 10, wherein either or both of the nickel salt adhering to the surface and the lead segregated on the surface layer of the wetted part are washed away.   The copper alloy according to any one of claims 1 to 12, comprising a protective film forming component containing at least a wax and a solvent component for dissolving the protective film forming component in water as the protective film. Protective film forming agent for preventing nickel elution from wetted equipment.   The nickel salt adhering as a residue inside the liquid-contacting equipment is removed, and the removal of metallic nickel at the mouth portion of the liquid-contacting equipment is suppressed. Cleaning agent for preventing nickel dissolution of wetted parts made of copper alloy.

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