阅读说明：本技术 一种含三价铬的电镀液及其应用 (Trivalent chromium-containing electroplating solution and application thereof ) 是由 黄恩礼 梁锦荣 洪文彦 洪大照 于 2020-12-30 设计创作，主要内容包括：本发明涉及一种含三价铬的电镀液,包括三价铬盐、含硫化合物、有机羧酸、有机胺盐。本发明还涉及上述含三价铬的电镀液在电镀工艺中的应用。其有益效果在于能显著提高电镀液的阴极电流效率与沉积速度,可达到降低生产成本和投入成本,并能提高生产效率的目的。(The invention relates to an electroplating solution containing trivalent chromium, which comprises trivalent chromium salt, a sulfur-containing compound, organic carboxylic acid and organic amine salt. The invention also relates to the application of the electroplating solution containing trivalent chromium in an electroplating process. The method has the advantages of remarkably improving the cathode current efficiency and the deposition speed of the electroplating solution, reducing the production cost and the input cost and improving the production efficiency.)

1. An electroplating solution containing trivalent chromium is characterized by comprising trivalent chromium salt, a sulfur-containing compound, an organic carboxylic acid and an organic amine salt.

2. The trivalent chromium-containing electroplating bath according to claim 1, comprising the following components in parts by mass:

and (3) water.

3. The trivalent chromium-containing electroplating bath as claimed in claim 1, wherein the trivalent chromium salt is selected from one or more of chromium sulfate, chromium chloride and chromium nitrate.

4. The trivalent chromium-containing electroplating bath according to claim 1, wherein the sulfur-containing compound is selected from the group consisting of one or more of cysteine, cystine, and methionine.

5. The trivalent chromium-containing electroplating bath as recited in claim 1, wherein the organic carboxylic acid is at least one selected from the group consisting of an aminocarboxylic acid and a hydroxycarboxylic acid.

6. The trivalent chromium-containing electroplating bath according to claim 1, wherein the organic amine salt is selected from one or more of fatty amine salt, alkanolamine salt and aromatic amine salt.

7. The trivalent chromium-containing electroplating bath as claimed in claim 1, further comprising one or more of an inorganic acid, a surfactant, and an inorganic metal compound.

8. The trivalent chromium-containing electroplating bath according to claim 7, wherein the inorganic acid is selected from boric acid or sulfuric acid.

9. The trivalent chromium-containing electroplating bath as claimed in claim 7, wherein the inorganic metal compound is selected from one or more of iron-containing compounds, cobalt-containing compounds, and nickel-containing compounds.

10. Use of a trivalent chromium-containing electroplating bath according to any one of claims 1-9 in an electroplating process.

Technical Field

The invention belongs to the field of electroplating liquid, and particularly relates to electroplating liquid containing trivalent chromium and application thereof.

Background

The electroplated chromium layer has high hardness, good wear resistance and corrosion resistance and excellent decoration, is often used as a decorative coating of electronic and electrical equipment, hardware and tools and the like and a functional coating of pistons, molds, shafts and the like, and is widely applied. At present, hexavalent chromium electroplating technology is adopted for most of chromium electroplating in the world, and the toxicity is high.

The toxicity of the trivalent chromium is 100 times less than that of the hexavalent chromium, and the trivalent chromium is considered to be an environment-friendly technology which is very hopeful to replace hexavalent chromium electroplating, so that the trivalent chromium electroplating solution has a good application prospect. However, the trivalent chromium-containing electroplating baths reported in the prior art have the major problems that: the sulfate system has the defects of low cathode current efficiency, low deposition speed and the like of the electroplating process due to the defects of low cathode current density, low tolerance of metal impurities and the like.

Disclosure of Invention

The main object of the present invention is to effectively improve the above-mentioned disadvantages.

The invention aims to provide a plating solution containing trivalent chromium, which is applied to a plating process and can effectively improve the cathode current efficiency, thereby improving the deposition speed of a plating layer and overcoming the defect of low deposition speed of the trivalent chromium plating solution of the traditional sulfate system.

The invention is realized by the following technical scheme:

an object of the present invention is to provide a trivalent chromium-containing plating solution, which is realized by:

an electroplating liquid containing trivalent chromium contains trivalent chromium salt, sulfur-containing compound, organic carboxylic acid and organic amine salt.

Further, the paint comprises the following components in parts by weight:

further, the trivalent chromium salt is selected from one or more of chromium sulfate, chromium chloride and chromium nitrate, and is used for providing the concentration of chromium ions in the electroplating solution.

Further, the sulfur-containing compound is selected from one or more of cysteine, cystine and methionine.

The sulfur-containing compound can uniformly blacken the plating layer.

Further, the organic carboxylic acid is selected from at least one of an aminocarboxylic acid or a hydroxycarboxylic acid.

The organic carboxylic acid can complex the metal and is the primary complexing agent for the electroplating solution.

Further, the organic amine salt is selected from one or more of fatty amine salt, alcohol amine salt and aromatic amine salt.

Further, the paint also comprises one or more of inorganic acid, surfactant and inorganic metal compound.

The surfactant is used for adjusting the precipitation potential of metal chromium ions in the electroplating solution, so that the metal chromium ions can be rapidly deposited within a certain current density range; the inorganic metal compound has a role of improving the dispersion effect of the plating solution.

Further, the inorganic acid is selected from boric acid or sulfuric acid, which is a pH buffer, and can make the solution more stable.

The surfactant may reduce the solution surface tension.

Further, the inorganic metal compound is selected from one or more of an iron-containing compound, a cobalt-containing compound, and a nickel-containing compound.

The inorganic metal compound can improve solution dispersibility.

It is another object of the present invention to provide the use of the trivalent chromium-containing electroplating solution described above in an electroplating process.

The invention has the beneficial effects that: the technical scheme of the invention can obviously improve the cathode current efficiency and the deposition speed of the electroplating process, thereby achieving the purposes of reducing the production cost and improving the production benefit.

Detailed Description

The present invention will be described with reference to specific examples. The starting components and processes used in the present invention are, unless otherwise specified, commercially available starting components and processes well known to those skilled in the art.

Example 1

An electroplating solution containing trivalent chromium comprises the following components in parts by weight:

the preparation method of the electroplating solution containing trivalent chromium comprises the following steps: adding the components into a reaction kettle according to the mass parts, and stirring to obtain the trivalent chromium-containing electroplating solution.

Example 2

An electroplating solution containing trivalent chromium comprises the following components in parts by weight:

the preparation method of the electroplating solution containing trivalent chromium comprises the following steps: adding the components into a reaction kettle according to the mass parts, and stirring to obtain the trivalent chromium-containing electroplating solution.

Example 3

An electroplating solution containing trivalent chromium comprises the following components in parts by weight:

the preparation method of the electroplating solution containing trivalent chromium comprises the following steps: adding the components into a reaction kettle according to the mass parts, and stirring to obtain the trivalent chromium-containing electroplating solution.

Comparative example 1

Comparative example 1 the formulation ingredients, parts of ingredients and preparation method were the same as example 1, with the only difference that comparative example 1 contained no cysteine.

Comparative example 2

Comparative example 2 the formulation ingredients, parts of ingredients and preparation method were the same as in example 1, with the only difference that comparative example 2 did not contain dodecylbenzenesulfonic acid isopropylamine salt.

Test example

The above examples 1 to 3 and comparative examples 1 to 2 were subjected to the sheet test in the Haake cell under the same operating conditions, and then the thickness of the black chromium plating layer was measured at a distance of 2cm and 5cm from the high current density region on each Haake sheet in the manner of the electrolytic destructive thickness test, respectively, and the cathode deposition rates of the respective combinations were compared.

The Hashima test flow is as follows:

polishing bronze sheet → electroplating gloss nickel for 10min → electroplating black trivalent chromium for 5min → passivating chromic acid of coating layer → drying by electric hair drier → testing film thickness

The results obtained are shown in table 1.

TABLE 1 film thickness measured at different places for examples 1 to 3 and comparative examples 1 to 2 in test examples

The above data fully illustrate that: by adding the cysteine and the organic amine salt, the cathode current efficiency of the electroplating process can be obviously improved, so that the cathode deposition speed of the process is also rapidly improved (the higher the deposition speed per unit speed is, the larger the film thickness value is). Thereby greatly shortening the electroplating time, reducing the investment of equipment and electroplating solution and lowering the production cost.