阅读说明：本技术 一种以烷基糖苷为添加剂成分的无氰电镀镉溶液 (Cyanide-free electroplating cadmium solution with alkyl glycoside as additive component ) 是由 张骐 潘峤 詹中伟 孙志华 宇波 彭超 于 2021-09-18 设计创作，主要内容包括：本发明属于电镀技术,涉及一种以烷基糖苷为添加剂成分的无氰电镀镉溶液。包括包括镉的氧化物或镉盐、络合剂或配位剂、导电盐、缓冲剂及添加剂,溶剂为水；本发明使用的烷基糖苷是具备糖苷基与烷基的非离子表面活性剂,既可以作为主光亮剂细化镀层晶粒、提高镀层光泽度,也可以作为整平剂提高镀层的均匀性。使用烷基糖苷作为电镀镉溶液的添加剂可以显著提高无氰电镀镉镀层的表面质量。本发明添加剂仅使用烷基糖苷一种即可制备出满足要求的镀层,不需要添加冗杂的走位剂、主光亮剂、载体光亮剂、辅助光亮剂等物质；为了使镀层获得更光亮的外观,可以添加镍盐制备镍镉合金；烷基糖苷是一种易生物降解材料,对环境危害性小。(The invention belongs to an electroplating technology, and relates to a cyanide-free electroplating cadmium solution taking alkyl glucoside as an additive component. Comprises cadmium oxide or cadmium salt, complexing agent or complexing agent, conductive salt, buffering agent and additive, wherein the solvent is water; the alkyl glycoside used in the invention is a nonionic surfactant with glycosyl and alkyl, which can be used as a main brightening agent to refine coating grains and improve coating glossiness, and can also be used as a leveling agent to improve coating uniformity. The alkyl glycoside is used as the additive of the cadmium electroplating solution, so that the surface quality of the cyanide-free cadmium electroplating layer can be obviously improved. The additive can prepare a coating meeting the requirement only by using one alkyl glycoside, and redundant dislocation agents, main brightening agents, carrier brightening agents, auxiliary brightening agents and other substances do not need to be added; in order to make the plating layer obtain a brighter appearance, nickel salt can be added to prepare nickel-cadmium alloy; the alkyl glycoside is a material which is easy to be biodegraded and has little harm to the environment.)

1. A cyanide-free electroplating cadmium solution taking alkyl glycoside as an additive component is characterized by comprising cadmium oxide or cadmium salt, a complexing agent or a complexing agent, a conductive salt, a buffering agent and an additive, wherein a solvent is water; wherein, the mass percentage of the oxide of cadmium or the salt of cadmium in the solution to the mass sum of the solute is 8 percent to 12 percent, the mass percentage of the complexing agent or the complexing agent in the solution to the mass sum of the solute is 20 percent to 35 percent, the mass percentage of the buffering agent in the solution to the mass sum of the solute is 3 percent to 10 percent, the mass percentage of the additive in the solution to the mass sum of the solute is 0.5 percent to 2 percent, the main component of the additive is alkyl glycoside, and the mass of the conductive salt in the solution is the rest of the solute.

2. The cyanide-free electroplated cadmium solution with alkyl glycoside as additive component as claimed in claim 1, wherein the cadmium oxide or cadmium salt comprises one or more of cadmium oxide, cadmium chloride, cadmium sulfate, cadmium methane sulfonate, and cadmium citrate.

3. The solution of claim 1, wherein the complexing agent or complexing agent comprises one or more of ammonium chloride, nitrilotriacetic acid and salts thereof, ethylenediaminetetraacetic acid and salts thereof, iminodisuccinic acid and derivatives thereof, hydroxyethylidene diphosphonic acid and salts thereof, hydantoin (hydantoin) and derivatives thereof, citric acid and salts thereof, and organic amines.

4. The cyanogen-free electroplated cadmium solution with alkyl glycoside as additive composition of claim 1 wherein the buffer is selected from the group consisting of but not limited to: carbonate, borate, methane sulfonate, citrate, nicotinate, acetate and hydrogen phosphate.

5. The cyanide-free cadmium electroplating solution with alkyl glycoside as additive as claimed in claim 1, wherein the conductive salt comprises one or more of sodium salt, potassium salt and ammonium salt.

6. The cyanide-free cadmium electroplating solution according to claim 1, wherein the alkyl glycoside is a nonionic surfactant having an alkyl group at the lipophilic end and a glycoside group at the hydrophilic end; wherein alkyl is a group containing only C, H elements, and glycoside is a group containing only C, H, O elements.

7. The cyanide-free cadmium electroplating solution according to claim 1, wherein the glycoside group is an acetal derivative group formed by reacting a hemiacetal hydroxyl group of a carbohydrate with a hydroxyl group of an alcohol or phenol to lose water.

8. The cyanogen-free electroplating solution of cadmium as claimed in claim 1, wherein the alkyl glycoside comprises one or more of APG0810, APG0812, APG1012, dodecyl glycoside, JFC-2G.

9. The cyanide-free electroplated cadmium solution with alkyl glycoside as additive component of claim 1, wherein the additive solute further comprises main brightener and the component is nickel metal salt.

Technical Field

The invention belongs to an electroplating technology, and relates to a cyanide-free electroplating cadmium solution taking alkyl glucoside as an additive component.

Background

With the continuous progress of national science and technology, the demand of high-performance surface treatment technology is higher and higher. The conventional cyanide-free cadmium plating process has the characteristics of rough crystallization and dull plating layer, which are the result of deliberately increasing the porosity of the plating layer in order to reduce the influence of the cadmium plating process on the hydrogen brittleness of a matrix. For pure metal coatings, hydrogen brittleness and corrosion resistance have a certain inverse relationship, and when the hydrogen brittleness risk of the process on a substrate is reduced by using a method for increasing the porosity of the coating, the corrosion resistance of the coating is inevitably seriously influenced. The low hydrogen embrittlement pure zinc electroplating process has not been developed to date enough to explain the difficulty of both hydrogen embrittlement and corrosion resistance of the process. With the popularization and application of the cyanide-free cadmium-titanium alloy electroplating process, the protection of high-strength steel can be realized by considering both low hydrogen brittleness and high corrosion resistance. The cyanide-free cadmium-titanium alloy electroplating process which is mainly developed by the Beijing aviation material research institute can be applied to 4340 ultrahigh-strength steel, and the neutral salt spray experiment is over 3000 hours. Under the circumstances, the continuous research and development and optimization of the low-hydrogen brittle electroplating pure cadmium process are not necessary, and the research focus should be transferred to the aspects of optimizing the appearance of the plating layer, improving the corrosion resistance of the plating layer and the like.

The cyanide-free cadmium electroplating solution mainly comprises cadmium ions, a complexing agent/complexing agent, a conductive salt, a buffering agent and an additive, wherein the additive can remarkably change the performance of a plating layer. The cyanide-free cadmium plating saccharide additive mainly comprises gluconic acid^[1]Saccharin^[2]Sucrose, sucrose^[3]For example, there may be used an organic substance having a sugar side group, such as an organic substance of a propargylamide polymer having a glucose side group and/or a propargylamide polymer having a lactose side group^[4]. The gluconic acid or part of organic matter containing sugar side groups is basically used as a metal masking agent or an auxiliary complexing agent, and only pure sugar, glucoside or part of organic matter containing glucoside can refine coating grains. In conclusion, alkyl glycosides containing glycosidic groups have potential as additives for electroplating cadmium.

The alkyl glycoside is a novel nonionic surfactant, the lipophilic end of which is alkyl, and the hydrophilic end of which is glycosyl. Wherein, the alkyl is a group only containing C, H two elements, and the form of the alkyl can be straight chain, or can contain branched chain, benzene ring and the like; the glycoside group is a group containing only C, H, O elements, and is an acetal derivative group formed by reacting a hemiacetal hydroxyl group of a carbohydrate with a hydroxyl group of an alcohol or phenol to lose water. Therefore, theoretically, it can play a role of refining crystal grains and leveling.

Alkyl glycoside as additive has been successfully applied to galvanization^[5]Copper plating^[6]Silver plating^[7]Tin plating^[8]And the like. However, in these processes, except for the galvanizing process, it is not necessary to use a saccharide as a process brightener (a substance such as gluconic acid is a complexing agent or a metal masking agent, not a brightener). In the galvanizing process, the saccharides can be used as brightening agents and are only used under the weak acid condition that the process system is chloride or sulfate and the like. In other words, most processes use only alkyl glycosides as surfactants or complexing agents, and the glycosidic groups contained in the alkyl glycosides do not exert their greatest effect. Therefore, the alkyl glycoside has different functions in the cadmium plating process from other plating species, can be used as a plating layer brightener in any cadmium plating process to refine grains and increase the glossiness of the plating layer, can also be used as a leveling agent of the plating solution, and is a universal and efficient electroplating additive.

Among them, references:

[1] guo Chongwu, Li Xiaoyang, Chenkang, etc. A potassium chloride cadmium cobalt alloy plating solution, its preparation method and plating process are disclosed in CN110079842A [ P ] 2019.

[2] A plating solution for the negative electrode of Ni-Cd battery and its preparing process are disclosed in CN101082136[ P ].

[3] A non-nickel black Sn-Co alloy plating solution and its electroplating technology are disclosed in CN101575720A [ P ] 2009.

[4] Guo Chong Wuwen, Potassium chloride cyanide-free cadmium titanium alloy plating solution, its preparation method and electroplating process are disclosed in CN110117803A [ P ] 2019.

[5] Zhangqi, Zhanzhongwei, Sun Shihua, etc. an efficient environment-protecting cyanide-free sulfate zinc-plating solution, CN106835208A [ P ] 2018.

[6] The patent refers to the field of 'compositions of macromolecular compounds'.

[7] Wang Haojie, Huangliangping, Yan \40532nd, a thiosulfate silver plating additive, a preparation method thereof and an electroplating solution containing the thiosulfate silver plating additive are CN108950616B [ P ] 2020.

[8] Chenchun, an ultrahigh-speed additive for electroplating pure Sn, CN109898105A [ P ] 2019.

Disclosure of Invention

The invention aims to: provides a cyanide-free cadmium electroplating process using alkyl glycoside as an additive component. The alkyl glycoside used in the process is a nonionic surfactant with glycosyl and alkyl, and can be used as a main brightening agent to refine coating grains and improve coating glossiness, and can also be used as a leveling agent to improve coating uniformity. The alkyl glycoside is used as the additive of the cadmium electroplating solution, so that the surface quality of the cyanide-free cadmium electroplating layer can be obviously improved.

The technical scheme of the invention is as follows: a cyanide-free electroplating cadmium solution with alkyl glycoside as an additive component comprises the following components: the solute comprises cadmium oxide or cadmium salt, complexing agent or complexing agent, conductive salt, buffering agent and additive, and the solvent is water; wherein, the mass percentage of the oxide of cadmium or the salt of cadmium in the solution to the mass sum of the solute is 8 percent to 12 percent, the mass percentage of the complexing agent or the complexing agent in the solution to the mass sum of the solute is 20 percent to 35 percent, the mass percentage of the buffering agent in the solution to the mass sum of the solute is 3 percent to 10 percent, the mass percentage of the additive in the solution to the mass sum of the solute is 0.5 percent to 2 percent, the main component of the additive is alkyl glycoside, and the mass of the conductive salt in the solution is the rest of the solute.

The cadmium oxide or cadmium salt comprises one or more of cadmium oxide, cadmium chloride, cadmium sulfate, cadmium methane sulfonate and cadmium citrate.

The complexing agent or complexing agent comprises one or more of ammonium chloride, nitrilotriacetic acid and its salt, ethylene diamine tetraacetic acid and its salt, iminodisuccinic acid and its derivative, hydroxyethylidene diphosphonic acid and its salt, hydantoin and its derivative, citric acid and its salt, and organic amine.

Classes of buffers include, but are not limited to: carbonate, borate, methane sulfonate, citrate, nicotinate, acetate and hydrogen phosphate.

The conductive salt comprises one or more of sodium salt, potassium salt and ammonium salt.

The alkyl glycoside is a nonionic surfactant, the lipophilic end of the alkyl glycoside is alkyl, and the hydrophilic end of the alkyl glycoside is glycosyl; wherein alkyl is a group containing only C, H elements, and glycoside is a group containing only C, H, O elements.

The glycoside group is an acetal derivative group formed by reacting a hemiacetal hydroxyl group of a carbohydrate with a hydroxyl group of an alcohol or phenol, with loss of water.

The alkyl glycoside comprises one or more of APG0810, APG0812, APG1012, dodecyl glycoside and JFC-2G.

The additive solute also comprises a main brightener, and the ingredient of the main brightener is nickel metal salt.

The invention has the advantages that: the additive can prepare a coating meeting the requirement only by using one alkyl glycoside, and redundant dislocation agents, main brightening agents, carrier brightening agents, auxiliary brightening agents and other substances do not need to be added; in order to make the plating layer obtain a brighter appearance, nickel salt can be added to prepare nickel-cadmium alloy; the alkyl glycoside is a material which is easy to be biodegraded and has little harm to the environment.

Detailed Description

The present invention is described in further detail below.

A cyanide-free electroplating cadmium solution with alkyl glycoside as an additive component comprises the following components: the solute comprises cadmium oxide or cadmium salt, complexing agent/complexing agent, conductive salt, buffering agent and additive, and the solvent is water. Wherein, the percentage of the total mass of the cadmium oxide or cadmium salt and the solute in the solution is 8% -12%, and the types include but are not limited to: cadmium oxide, cadmium chloride, cadmium sulfate, cadmium methane sulfonate, cadmium citrate, and the like. The percentage of complexing/complexing agent to the total mass of solute in the solution is 20% to 35%, and the types include but are not limited to: ammonium chloride, nitrilotriacetic acid and salts thereof, ethylenediaminetetraacetic acid and salts thereof, iminodisuccinic acid and derivatives thereof, hydroxyethylidene diphosphonic acid and salts thereof, hydantoin (hydantoin) and derivatives thereof, citric acid and salts thereof, organic amines and the like. The percentage of the total mass of the buffer and solute in the solution is 3% to 10%, and the types thereof include but are not limited to: carbonates, borates, methane sulfonates, citrates, nicotinates, acetates, hydrogen phosphates, and the like. The total mass percentage of the additive and the solute in the solution is 0.5-2%, and the main component of the solution is alkyl glycoside. The mass of the conductive salt in the solution is the balance of the solute, and the types thereof include but are not limited to: sodium, potassium, ammonium salts, and the like.

The working principle of the invention is as follows: the alkyl glycoside is a novel nonionic surfactant, the lipophilic end of which is alkyl, and the hydrophilic end of which is glycosyl. Wherein, the alkyl is a group only containing C, H two elements, and the form of the alkyl can be straight chain, or can contain branched chain, benzene ring and the like; the glycoside group is a group containing only C, H, O elements, and is an acetal derivative group formed by reacting a hemiacetal hydroxyl group of a carbohydrate with a hydroxyl group of an alcohol or phenol to lose water. Therefore, the alkyl glycoside used in the solution is a nonionic surfactant having a glycoside group and an alkyl group, and can be used as a main brightener to refine coating crystal grains and improve coating glossiness, and can also be used as a leveler to improve coating uniformity.

A method for preparing cyanide-free electroplating cadmium solution with alkyl glycoside as additive component comprises:

1) preparing a metal cadmium solution: weighing calculated amount of metal cadmium oxide or cadmium salt, and completely dissolving with diluted acid and/or deionized water.

2) Preparation of complexing agent/complexing agent solution: the calculated amount of complexing/complexing agent is weighed, completely dissolved with acid/base and adjusted to the corresponding pH.

3) Slowly adding the metal cadmium solution into the complexing agent/complexing agent solution, and uniformly stirring.

Adding conductive salt and buffer, stirring, and adjusting pH to specified value.

4) Adding additive, stirring, and adding water to desired volume.

Example 1

The formula of the main salt of the electroplating solution is as follows:

cadmium sulfate: 30 g/L;

ammonium chloride: 150 g/L;

ethylene diamine tetraacetic acid: 30 g/L;

ammonium acetate: 20 g/L;

APG0810 (alkyl glycoside): 0.5g/L

Nickel sulfate: 0.3g/L

pH：6～7；

T：15-30℃

Current density: 0.5 to 2.0A/dm²。

Example 2

Cadmium oxide: 35 g/L;

methane sulfonic acid: 60 g/L;

hydroxyethylidene diphosphonic acid: 120 g/L;

potassium carbonate: 60 g/L;

APG0812 (alkyl glycoside): 0.5 g/L:

pH：9～11；

T：15-30℃

current density: 1.0 to 5.0A/dm²。

Example 3

Cadmium oxide: 35 g/L;

methane sulfonic acid: 60 g/L;

5, 5-dimethylhydantoin: 120 g/L;

potassium carbonate: 60 g/L;

dodecyl glycoside (alkyl glycoside): 0.5 g/L:

pH：9～11；

T：15-30℃

current density: 1.0 to 5.0A/dm²。

Three different metal cadmium ion sources, three different complexing agents or coordination agents and three alkyl glucosides with different structures are used in the three embodiments, and the cadmium plating layer with bright appearance, fine crystallization, good bonding force and excellent corrosion resistance can be prepared.