CN110965086A - Acidic zinc plating impurity removing agent and application thereof - Google Patents
Acidic zinc plating impurity removing agent and application thereof Download PDFInfo
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- CN110965086A CN110965086A CN201911149621.5A CN201911149621A CN110965086A CN 110965086 A CN110965086 A CN 110965086A CN 201911149621 A CN201911149621 A CN 201911149621A CN 110965086 A CN110965086 A CN 110965086A
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- impurity removing
- removing agent
- zinc plating
- plating
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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
- C25D3/22—Electroplating: Baths therefor from solutions of zinc
Abstract
The invention discloses an acid galvanizing impurity removing agent and application thereof, wherein the acid galvanizing impurity removing agent comprises the following components in percentage by weight: 10% -40% of a chelating agent; 15% -45% of a synergist; 20 to 45 percent of precipitator. The acidic zinc plating impurity removing agent can specifically complex ions such as iron, copper, lead and the like, generates a precipitate insoluble in water under an acidic condition, and is easy to filter and remove; the acid zinc plating impurity removing agent does not contain strong oxidizing compounds such as hydrogen peroxide and potassium permanganate, side effects caused by damage of organic additives in working liquid due to oxidation reaction are avoided, effective components in the impurity removing agent do not have any negative influence on the acid zinc plating additives, precipitates are generated at a working temperature within a certain time after the impurities are added according to the amount, and metal impurities in the working liquid can be removed under the condition of no production stop by matching with a filter for circulating filtration. The acid zinc plating impurity removing agent can also improve the impurity resistance and corrosion resistance of the acid zinc plating electrolyte, increase the cathode polarization, refine the plating crystallization and improve the plating quality.
Description
Technical Field
The invention belongs to the field of metal corrosion protection and surface treatment, and particularly relates to an acidic zinc plating impurity removing agent and application thereof.
Background
The zinc coating is one of the most important, most economical and most convenient means for preventing steel from being corroded, is a large amount of wide plating seeds in the electroplating industry, is also the protective decorative coating which is most widely applied, and has excellent protection effect on a steel substrate. In the acid galvanizing process, the content of metal ions in the plating solution is continuously accumulated and increased due to reasons of raw material impurity introduction, poor cleaning introduction after pickling, corrosion introduction caused by the fact that steel workpieces or copper hooks and the like fall into the bath solution, and the like, and finally the problems of unstable plating solution performance, reduced cylinder printing, dispersing and deep plating capability, blackened light and even influence on passivation performance and the like are caused.
At present, the main method for industrially treating metal impurities in acidic zinc plating is a hydrogen peroxide or potassium permanganate oxidation method, and the main principle is to oxidize Fe2+Oxidation to Fe3+And together with Ni2+、Cu2+The insoluble precipitate formed after the pH value of the plating solution is adjusted by the plasma ions is filtered and removed. The method has wide application, but has obvious defects, and hydrogen peroxide and potassium permanganate are strong oxidant type dangerous chemicals and belong to easily made toxic or explosive chemicals, so that the purchase and use of raw materials are restricted to a certain extent; in addition, such strong oxidizing agents cannot specifically oxidize metal ions, and also oxidize additive components in the working fluid after addition, for example, o-chlorobenzaldehyde in the brightener is oxidized into o-chlorobenzoic acid to form organic impurities, the brightener effect is damaged, the plating layer in a high current density area is burnt, the plating layer is mixed with metal hydroxide, and the plating layer is poor in corrosion resistance and easy to discolor due to excessive accumulation of organic impurities in the plating solution. The addition amount of potassium permanganate is difficult to control, and the problems of turbid plating solution and the like are caused.
Disclosure of Invention
Based on the defects in the prior art, the invention provides an acid zinc plating impurity removing agent which does not contain strong oxidizing compounds such as hydrogen peroxide and potassium permanganate and the like and application thereof.
The technical scheme provided by the invention is as follows:
an acid zinc plating impurity removing agent comprises the following components in percentage by weight:
10% -40% of a chelating agent;
15% -45% of a synergist;
20 to 45 percent of precipitator.
On the basis of the technical scheme, the chelating agent is selected from 2, 2-pyridone-4, 4-dimethylOne or more of 3-thiosemicarbazone, N-oxide-3-hydroxy-2, 6-dimethyl-4-pyridone and 2-pyridone-2-methyl-3-thiosemicarbazone. Chelating agent used in the present invention for Fe2+Has weak oxidation effect, and can convert Fe at the specified time and electroplating working temperature2+Oxidation to Fe3+So as to form a precipitate under the weak acidity condition, the chelating agent molecules also contain multi-base ligands, and the chelating agent can chelate metal ions such as iron ions, copper ions and the like, maintain the potential balance of the ligands under the weak acidity condition, form a stable chelate with the metal ions, and prevent impurity metal ions and zinc ions from codepositing in the coating to cause negative effects on the coating.
On the basis of the technical scheme, the synergist is selected from one or more of glucose, glucoside and glucose amide. The synergist used in the invention is mainly glucose and derivatives thereof, the substances are polyhydroxy compounds and have certain complexation, and aldehyde groups contained in the synergist have certain reducibility, so that the stability of the impurity metal ion chelate can be maintained, and the influence of the impurity metal ions redissolved in a plating solution on the coordination performance of the chelating agent on the metal impurity ions in the electroplating process can be prevented.
On the basis of the technical scheme, the precipitating agent is composed of H3BO3、ZnO、MnCl2The components are mixed according to the mass ratio of 4:5: 1. The precipitating agent used in the invention is in H3BO3、ZnO、MnCl2Under the synergistic effect of the three components, Fe can be transformed3+The equilibrium potential of the formed metal chelate is obviously shifted negatively, the solubility product of the chelate is smaller at the working temperature, and the metal chelate can be separated out from the plating solution in a precipitation mode.
On the basis of the technical scheme, the weight percentage of the chelating agent is 40 wt%, the weight percentage of the synergist is 25 wt%, and the weight percentage of the precipitator is 35 wt%.
The invention also provides electrolyte, wherein the acid galvanizing impurity removing agent is added into the electrolyte, and the addition amount of the acid galvanizing impurity removing agent is 1-3 g/L.
The invention also provides a method for preparing the electrolyte, which comprises the following steps: adding the uniformly mixed impurity removing agent into the electrolyte according to the addition amount of 1-3g/L under the stirring condition of 25-55 ℃, continuing stirring for 20-30 minutes after the addition, standing for several hours, filtering, discarding the precipitate, and taking a clear solution.
On the basis of the technical scheme, if a filter is used for circulating filtration in production, the impurity removing agent can be directly added into the filter for circulating filtration without stopping production.
Compared with the prior art, the invention has the following advantages and beneficial effects:
in the existing acid zinc plating impurity removal method, a strong oxidant is adopted to remove metal ions, meanwhile, effective components in the additive can be damaged, so that a plating layer in a high current density area is burnt, the plating layer is mixed with metal hydroxide, a brightener is decomposed to become organic impurities, and the plating layer is poor in corrosion resistance and easy to discolor due to excessive accumulation of the organic impurities in a plating solution.
The acid zinc plating impurity removing agent provided by the invention can not damage organic additives in the working solution to generate side effects due to oxidation reaction, effective components in the impurity removing agent do not have any negative effect on the acid zinc plating working solution, precipitates are generated at a working temperature within a certain time after the impurity removing agent is added according to the amount, and metal impurities in the working solution can be removed under the condition of no production stop by matching with a filter for circulating filtration. The acid zinc plating impurity removing agent can also improve the impurity resistance and corrosion resistance of the acid zinc plating electrolyte to a certain degree, increase the cathode polarization, refine the plating crystallization and improve the plating quality.
Drawings
FIG. 1 is a gold phase diagram of a plating layer to which iron ions are not added in a plating solution;
FIG. 2 is a diagram showing a gold phase of a plating layer in which iron ions are added to a plating solution;
FIG. 3 is a diagram showing a gold phase of a plating layer in which iron ions and an impurity removing agent are simultaneously added to a plating solution;
FIG. 4 is a gold phase diagram of a coating with different impurity levels; wherein, FIGS. 4(a1) and 4(a2) both represent the plating layer without iron ions added to the plating solution; FIGS. 4(b1) and 4(b2) show the plating layer in which copper ions and nickel ions are added to the plating solution, respectively; FIGS. 4(c1) and 4(c2) show the plating solutions with copper ions and impurities and nickel ions and impurities added, respectively.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1: preparation of base liquid
1. Preparing a potassium salt galvanizing base solution:
(1) dissolving potassium chloride and zinc chloride in 2/3 g of water, dissolving boric acid in boiling water, adding, and stirring.
(2) Filtering to remove insoluble impurities in the plating solution.
(3) And measuring the pH value, adjusting the pH value to a process range of 5-6, adding water to a specified volume, and uniformly stirring to obtain the potassium salt galvanizing base solution with the potassium chloride concentration of 200g/L, the zinc chloride concentration of 70g/L and the boric acid concentration of 25 g/L.
2. Preparing a sulfate zinc plating base solution:
(1) the zinc sulphate was dissolved in a metered amount with a total volume of 2/3 warm water.
(2) Dissolving boric acid in 80 deg.C hot water, stirring, and adding into the above solution.
(3) Adding zinc powder 1g/L, stirring, standing for 2 hours, precipitating and filtering.
(4) Supplementing water level to a specified volume, and uniformly stirring to obtain the sulfate galvanizing base solution with zinc sulfate concentration of 300g/L and boric acid concentration of 25 g/L.
Example 2
Taking 40 parts by weight of N-oxide-3-hydroxy-2, 6-dimethyl-4-pyridone, 25 parts by weight of D-glucose and 35 parts by weight of H with the weight ratio of 4:5:13BO3、ZnO、MnCl2And mixing the three mixtures to obtain the acid zinc plating impurity removing agent.
Example 3
Taking 30 parts by weight of 3-2, 2-pyridone-4, 4-dimethyl-3-condensed ammoniaThiosemicarbazide, 25 parts by weight of 2-pyridone-2-methyl-3-thiosemicarbazone, 5 parts by weight of cellobiase, 40 parts by weight of H in a weight ratio of 4:5:13BO3、ZnO、MnCl2And mixing the three mixtures to obtain the acid zinc plating impurity removing agent.
Example 4
First, the following three sets of plating solutions were prepared:
a group: adding a LAN-918 brightening agent (0.6ml/L) and a LAN-919 softening agent (25ml/L) into the base solution of the potassium chloride galvanizing plating solution to obtain plating solution a; the gold phase diagram of the plating layer is shown in figure 1;
b group: FeSO is added on the basis of the plating solution a4To obtain Fe2+Electroplating solution b with the concentration of 2000 mg/L; the gold phase diagram of the plating layer is shown in FIG. 2;
and c, group: adding the acid galvanizing impurity removing agent prepared in the embodiment 2 on the basis of the electroplating solution b to obtain an electroplating solution c with the concentration of the acid galvanizing impurity removing agent being 3 g/L; the gold phase diagram of the plating is shown in fig. 3.
The three sets of plating solutions were subjected to the Hull cell test: adopting a standard Hull cell with the capacity of 267mL, containing 250mL of plating solution, and placing the Hull cell in a constant-temperature water bath at 25 ℃; a brass sheet (6 cm. times.10 cm) having a thickness of 2mm and a mirror surface polished by a cloth wheel was used as a cathode test piece, and an electrolytic zinc plate was used as an anode, and the test was carried out at a constant current density. The conditions of the electroplating process are as follows: current density: 1A/dm2Temperature: 25 ℃, pH value of 5.0 and electroplating time of 10 min.
The pretreatment process of the plating piece comprises the following steps: alkaline degreasing → hot water rinsing → tap water rinsing → acid pickling activation → tap water rinsing → acid galvanizing → tap water rinsing → blow drying → performance test.
And (3) observing the surface appearance: and observing the surface appearance of the plating layer prepared by the three groups of electroplating liquids by adopting a 53X-type upright metallographic microscope. It can be seen that when the iron impurity is added to group b, high zone scorch is exhibited in the Hull cell coupon, because the iron impurity is too high, and gradually oxidized to Fe (OH) in the bath3Suspended particles adhered to the surface of the coating to make the hand feel rough and even form visible particles, and we can pass through the micro-morphologyIt is seen that the nodules are attached to the plating layer, the obvious improvement is achieved after the impurity removing agent is added, and through analysis, after the acid zinc plating impurity removing agent in the example 2 is added to the group c, Fe in the plating solution2+The content is reduced to below 80 mg/L.
Example 5
First, the following three sets of plating solutions were prepared:
a group: adding sulfate rapid galvanizing additive AS-30(16ml/L) into the two groups of sulfate galvanizing plating solution base solutions to obtain plating solution a1 and plating solution a 2; the gold phase diagrams of the plating layers are respectively shown in FIG. 4(a1) and FIG. 4(a 2);
b group: cu was added to the plating solution a1 and the plating solution a2, respectively2+And Ni2+To obtain Cu2+Electroplating solution b1 with Ni concentration of 15mg/L2+Electroplating solution b2 with the concentration of 15 mg/L; the gold phase diagrams of the plating layers are respectively shown in FIG. 4(b1) and FIG. 4(b 2);
and c, group: adding the acid galvanizing impurity removing agent of the example 3 into the electroplating solution b1 and the electroplating solution b2 respectively, wherein the adding amount of the acid galvanizing impurity removing agent is 3g/L, and obtaining electroplating solution c1 and electroplating solution c 2; the gold phase diagrams of the plating layers are shown in fig. 4(c1) and fig. 4(c2), respectively.
The three sets of plating solutions were subjected to the Hull cell test: adopting a standard Hull cell with the capacity of 267mL, containing 250mL of plating solution, and placing the Hull cell in a constant-temperature water bath (35 ℃); a brass sheet (6 cm. times.10 cm) having a thickness of 2mm and a mirror surface polished by a cloth wheel was used as a cathode test piece, and an electrolytic zinc plate was used as an anode, and the test was carried out at a constant current density. The conditions of the electroplating process are as follows: current density: 5A/dm2Temperature: 35 ℃, pH value of 5.0 and electroplating time of 5 min.
The pretreatment process of the plating piece comprises the following steps: alkaline degreasing → hot water rinsing → tap water rinsing → acid pickling activation → tap water rinsing → acid galvanizing → tap water rinsing → blow drying → performance test.
And (3) observing the surface appearance: and observing the surface appearance of the plating layer prepared by the three groups of electroplating liquids by adopting a 53X-type upright metallographic microscope. It can be seen that when copper metal ion impurities are added, the plating layer appears dark, loose dark plating layer and pinholes appear in the Hull cell test piece, the plating layer added with nickel ions has fine rough condition, and the plating layer is obviously improved after the acid zinc plating impurity removing agent is added.
The present invention is illustrated by the above examples, but the present invention is not limited thereto, and the composition and the addition amount of the compound in the above examples are not meant to be necessarily dependent on the present invention, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. An acid zinc plating impurity removing agent is characterized in that: the paint consists of the following components in percentage by weight:
10% -40% of a chelating agent;
15% -45% of a synergist;
20 to 45 percent of precipitator.
2. The acid zinc plating edulcoration agent according to claim 1, characterized in that: the chelating agent is one or more of 2, 2-pyridone-4, 4-dimethyl-3-thiosemicarbazone, N-oxide-3-hydroxy-2, 6-dimethyl-4-pyridone and 2-pyridone-2-methyl-3-thiosemicarbazone.
3. The acid zinc plating edulcoration agent according to claim 1, characterized in that: the synergist is one or more of glucose, glucoside and glucose amide.
4. The acid zinc plating edulcoration agent according to claim 1, characterized in that: the precipitating agent is composed of H3BO3、ZnO、MnCl2The components are mixed according to the mass ratio of 4:5: 1.
5. The acid zinc plating edulcoration agent according to claim 1, characterized in that: the chelating agent accounts for 40 wt%, the synergist accounts for 25 wt%, and the precipitant accounts for 35 wt%.
6. An electrolyte, characterized by: the acid galvanizing trash remover as claimed in claim 1 is added, and the addition amount of the acid galvanizing trash remover is 1-3 g/L.
7. A method of preparing the electrolyte of claim 6, comprising the steps of: adding the uniformly mixed impurity removing agent into the electrolyte according to the addition amount of 1-3g/L under the stirring condition of 25-55 ℃, continuing stirring for 20-30 minutes after the addition, standing for several hours, filtering, discarding the precipitate, and taking a clear solution.
8. The method of claim 7, wherein: under the condition of no stop, the impurity removing agent is directly added into the electrolyte in the filter to carry out circulating filtration.
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| US3920528A (en) * | 1973-10-25 | 1975-11-18 | Schering Ag | Bright acid zinc plating method and electrolyte |
| CN1486279A (en) * | 2000-12-22 | 2004-03-31 | ��ʲ | Composition comprising an oxidizing and complexing compound |
| CN101407927A (en) * | 2008-09-11 | 2009-04-15 | 许技华 | Alkaline zinc-plating additive and process used for cyaniding liquid plating conversion thereof |
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| CN101748450A (en) * | 2010-01-14 | 2010-06-23 | 杭州顿力实业有限公司 | EDP environmental-friendly zinc plating solution and preparation method |
| CN104164686A (en) * | 2014-07-22 | 2014-11-26 | 武汉钢铁(集团)公司 | Acidic electrolytic zinc plating solution additive and application method thereof |
| CN104694983A (en) * | 2015-03-19 | 2015-06-10 | 南通创源电化学科技有限公司 | Acidic electroplating zinc-nickel alloy electrolyte, preparation method and electroplating method |
| CN104945564A (en) * | 2015-06-25 | 2015-09-30 | 中国科学技术大学 | Method for preparing block cationic water-borne polyurethane iron (III) chelates |
| CN105037595A (en) * | 2015-07-06 | 2015-11-11 | 中国科学技术大学 | High-molecular iron (III) chelating agent based on 3-hydroxyl-4-pyridinone compounds and preparation method thereof |
| CN105463521A (en) * | 2016-01-07 | 2016-04-06 | 杭州东方表面技术有限公司 | Environment-friendly cyanide-free alkaline zinc plating purification additive |
| CN105538464A (en) * | 2015-12-11 | 2016-05-04 | 浙江省博物馆 | Method for removing ironic sulfide in wooden artifacts |
| CN109295480A (en) * | 2018-11-09 | 2019-02-01 | 湖北吉和昌化工科技有限公司 | A kind of acid zinc plating electroplate liquid |
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2019
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3920528A (en) * | 1973-10-25 | 1975-11-18 | Schering Ag | Bright acid zinc plating method and electrolyte |
| CN1486279A (en) * | 2000-12-22 | 2004-03-31 | ��ʲ | Composition comprising an oxidizing and complexing compound |
| CN101407927A (en) * | 2008-09-11 | 2009-04-15 | 许技华 | Alkaline zinc-plating additive and process used for cyaniding liquid plating conversion thereof |
| CN101643925A (en) * | 2009-09-01 | 2010-02-10 | 大连海事大学 | Non-cyanide converting method for cyanide plated zinc |
| CN101748450A (en) * | 2010-01-14 | 2010-06-23 | 杭州顿力实业有限公司 | EDP environmental-friendly zinc plating solution and preparation method |
| CN104164686A (en) * | 2014-07-22 | 2014-11-26 | 武汉钢铁(集团)公司 | Acidic electrolytic zinc plating solution additive and application method thereof |
| CN104694983A (en) * | 2015-03-19 | 2015-06-10 | 南通创源电化学科技有限公司 | Acidic electroplating zinc-nickel alloy electrolyte, preparation method and electroplating method |
| CN104945564A (en) * | 2015-06-25 | 2015-09-30 | 中国科学技术大学 | Method for preparing block cationic water-borne polyurethane iron (III) chelates |
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Application publication date: 20200407 |