Treatment process for coloring black oxide film on metal surface

文档序号：629310 发布日期：2021-05-11 浏览：23次中文

阅读说明：本技术 一种用于金属表面着黑色氧化膜的处理工艺 (Treatment process for coloring black oxide film on metal surface ) 是由阳文于 2020-12-08 设计创作，主要内容包括：本发明公开了一种用于金属表面着黑色氧化膜的处理工艺,包括：将金属工件置于前处理剂中,进行除油、除氧化皮和活化处理,然后再进行水洗；将前处理的金属工件置于预黑剂中,进行预发黑处理；将预发黑的金属工件置于发黑剂中,进行发黑着氧化膜处理,再将发黑处理后的金属工件进行水洗,水洗后烘干即得。本发明的处理工艺将除油、除锈、抛光、活化通过前处理剂一步完成,略除前端大量繁琐工序,降低生产成本,后续发黑处理采用两步发黑,大大提升发黑效率,使得所制备的氧化膜均匀纯正,附着力强,膜层坚固耐蚀性能好,且配方中不含有对环境和操作人员带来危害风险的具有毒性的化学物质,健康环保。(The invention discloses a treatment process for coloring a black oxide film on a metal surface, which comprises the following steps: putting the metal workpiece into a pretreatment agent, performing oil removal, descaling and activation treatment, and then washing with water; putting the pretreated metal workpiece into a pre-blackening agent for pre-blackening treatment; and putting the metal workpiece to be blackened into a blackening agent, carrying out blackening and oxidation film coating treatment, washing the metal workpiece after the blackening treatment with water, and drying the washed metal workpiece to obtain the metal workpiece. The treatment process of the invention completes oil removal, rust removal, polishing and activation in one step by the pretreatment agent, omits a large number of complicated procedures at the front end, reduces the production cost, adopts two-step blackening for the subsequent blackening treatment, greatly improves the blackening efficiency, ensures that the prepared oxide film is uniform and pure, has strong adhesive force and good firm and corrosion-resistant performance, does not contain toxic chemical substances which bring harm risks to the environment and operators in the formula, and is healthy and environment-friendly.)

1. A treatment process for coloring a black oxide film on a metal surface is characterized by comprising the following steps:

s1: placing the metal workpiece in a pretreatment agent, performing oil removal, descaling and activation treatment, and then performing water washing to obtain a pretreated metal workpiece;

s2: placing the pretreated metal workpiece in a pre-blackening agent, and performing pre-blackening treatment to obtain a pre-blackened metal workpiece;

s3: and putting the metal workpiece which is pre-blackened into a blackening agent, carrying out blackening and oxide film coating treatment, washing the metal workpiece which is subjected to the blackening treatment with water, and drying the washed metal workpiece to obtain the metal workpiece with the black oxide film.

2. The treatment process for coloring a black oxide film on a metal surface according to claim 1, wherein the pretreatment agent comprises the following components in percentage by mass:

3% -5% of organic acid; 1% -3% of phosphoric acid; 2-5% of fatty alcohol-polyoxyethylene ether; 1% -2% of coconut oil fatty diethanol amide; 1% -3% of corrosion inhibitor; the balance of water.

3. The process according to claim 2, wherein the organic acid is one or a combination of two or more of oxalic acid, tartaric acid, maleic acid and citric acid; the corrosion inhibitor is one or two of thiourea and urotropine.

4. The process according to claim 2, wherein the pretreatment agent is prepared by a method comprising:

dissolving organic acid with water, adding a corrosion inhibitor, stirring until the organic acid is dissolved, then sequentially adding phosphoric acid, fatty alcohol-polyoxyethylene ether and coconut oil fatty acyl diethanolamine, in the adding process of the phosphoric acid, the fatty alcohol-polyoxyethylene ether and the coconut oil fatty acyl diethanolamine, stirring for 1min-2min after adding one component, then adding the next component, and obtaining the pretreatment agent after all the components are added and dissolved.

5. The treatment process for coloring a black oxide film on a metal surface according to claim 1, wherein the pre-blackening agent comprises the following components in percentage by mass:

2% -5% of persulfate; 15% -20% of inorganic base; the balance of water.

6. The treatment process for the metal surface colored with the black oxide film according to claim 5, wherein the persulfate is one or a combination of two or more of sodium persulfate, potassium persulfate and ammonium persulfate; the inorganic alkali is one or a composition of more than two of potassium hydroxide, sodium hydroxide and lithium hydroxide.

7. The process according to claim 5, wherein the pre-blackening agent is prepared by a method comprising:

and (3) completely dissolving the persulfate by using water, adding the inorganic base, and stirring until the persulfate is completely dissolved to obtain the pre-blackening agent.

8. The treatment process for coloring a black oxide film on a metal surface according to claim 1, wherein the blackening agent comprises the following components in percentage by mass:

5% -10% of persulfate; 2% -5% of a chelating agent; 1% -3% of sodium polyacrylate; 3% -8% of polyethylene glycol; 1% -2% of copper salt; the balance of water.

9. The treatment process for the metal surface colored with the black oxide film according to claim 8, wherein the persulfate is one or a combination of two or more of sodium persulfate, potassium persulfate and ammonium persulfate; the chelating agent is one or a composition of more than two of sodium citrate, sodium pyrophosphate, sodium tripolyphosphate and potassium pyrophosphate; the copper salt is one or a composition of more than two of copper chloride, copper sulfate and copper carbonate.

10. The process according to claim 8, wherein the blackening agent is prepared by a method comprising:

and (2) completely dissolving persulfate by using water, sequentially adding a chelating agent, sodium polyacrylate, copper salt and polyethylene glycol, adding the next component after stirring until the component is completely dissolved in the adding process of the chelating agent, the sodium polyacrylate, the copper salt and the polyethylene glycol, and obtaining the blackening agent after all the components are completely added and dissolved.

Technical Field

The invention relates to the technical field of metal surface treatment, in particular to a treatment process for coating a black oxide film on a metal surface, and more particularly relates to a treatment process for blackening a coating film on the surface of copper and copper alloy.

Background

Copper and its alloy have excellent physical and chemical properties, so that it can be extensively used in the fields of domestic electric appliances, communication, spaceflight and hardware, etc. However, copper and its alloys are easily corroded by harmful gases in the atmosphere, and the service performance of the products is affected, so that oxidation treatment is required.

The oxidation blackening treatment is a surface anticorrosion and decoration technology widely applied to machinery manufacturing, precise instruments, instruments and daily necessities. Currently, the blackening process is a chemical coloring liquid, which can be classified into a sulfur series, a selenium series, a copper-ammonia series, and the like. Each of the coloring liquids has its drawbacks, such as: selenium dioxide in the selenium coloring liquid is extremely toxic, which can cause environmental pollution; the film colored by the sulfur-based coloring liquid has uneven color and loose black film; the copper-ammonia coloring liquid has continuous peculiar smell, the operation environment is worse, and the coloring liquid has quick failure.

Patent CN 101497996 a discloses a chemical process for coloring copper ink, which mainly uses sodium persulfate as an oxidant, and cooperates with sodium hydroxide to react, so as to generate copper oxide on the surface of copper.

Patent CN 106222645 a discloses a chemical blackening method for brass surface, which mainly utilizes the copper ammonia complex generated by the reaction of copper salt and ammonium salt, and then generates redox reaction with copper on the brass surface to form a black film layer, the system is an upgraded version of copper-ammonia, but still can not avoid the factors of fast black liquor failure, unstable blackening, poor operating environment, etc.

Patent CN 110042379 a discloses a copper blackening agent, which contains selenious acid, belongs to a selenium coloring system, but the substance is extremely toxic, and is easy to bring potential safety hazards and cause harm to the environment.

Disclosure of Invention

In order to overcome the defects of the prior art, one of the purposes of the invention is to provide a treatment process for coating a black oxide film on the surface of metal, which is suitable for coating a black oxide film on the surface of copper and copper alloy, the coloring process omits a large number of complicated procedures such as polishing, activating oxide scale and the like, can simultaneously meet the coloring requirements of pure copper and brass, and the colored film layer of the process has the advantages of firmness, strong adhesion, uniform and pure black film, no chemical substances causing harm risks to the environment and operators, and is healthy and environment-friendly.

The invention is realized by adopting the following technical scheme:

a treatment process for coloring a black oxide film on a metal surface comprises the following steps:

s1: placing the metal workpiece in a pretreatment agent, performing oil removal, descaling and activation treatment, and then performing water washing to obtain a pretreated metal workpiece;

s2: placing the pretreated metal workpiece in a pre-blackening agent, and performing pre-blackening treatment to obtain a pre-blackened metal workpiece;

Further, the pretreatment agent comprises the following components in percentage by mass:

3% -5% of organic acid; 1% -3% of phosphoric acid; 2-5% of fatty alcohol-polyoxyethylene ether; 1% -2% of coconut oil fatty diethanol amide; 1% -3% of corrosion inhibitor; the balance of water.

Preferably, the organic acid is one or a combination of more than two of oxalic acid, tartaric acid, maleic acid and citric acid; the corrosion inhibitor is one or a composition of more than two of thiourea and urotropin.

Preferably, the preparation method of the pretreatment agent comprises the following steps:

Further, the pre-blackening agent comprises the following components in percentage by mass:

2% -5% of persulfate; 15% -20% of inorganic base; the balance of water.

Preferably, the persulfate is one or a composition of more than two of sodium persulfate, potassium persulfate and ammonium persulfate; the inorganic alkali is one or a composition of more than two of potassium hydroxide, sodium hydroxide and lithium hydroxide.

Preferably, the preparation method of the pre-blackening agent comprises the following steps:

and (3) completely dissolving the persulfate by using water, adding the inorganic base, and stirring until the persulfate is completely dissolved to obtain the pre-blackening agent.

Further, the blackening agent comprises the following components in percentage by mass:

5% -10% of persulfate; 2% -5% of a chelating agent; 1% -3% of sodium polyacrylate; 3% -8% of polyethylene glycol; 1% -2% of copper salt; the balance of water.

Preferably, the persulfate is one or a composition of more than two of sodium persulfate, potassium persulfate and ammonium persulfate; the chelating agent is one or a composition of more than two of sodium citrate, sodium pyrophosphate, sodium tripolyphosphate and potassium pyrophosphate; the copper salt is one or a composition of more than two of copper chloride, copper sulfate and copper carbonate.

Preferably, the preparation method of the blackening agent comprises the following steps:

The above treatment process is preferably used for applying a black oxide film on the surface of copper and its alloys, i.e. the metal is copper and its alloys, which is more suitable for the oxidation colouring of pure copper and brass.

Compared with the prior art, the invention has the beneficial effects that:

the treatment process disclosed by the invention completes oil removal, rust removal, polishing and activation in one step through the pretreatment agent, omits a large number of complicated procedures at the front end, reduces the production cost, adopts two-step blackening for subsequent blackening treatment, greatly improves the blackening efficiency, ensures that the prepared oxide film is uniform and pure, has strong adhesive force and good firm and corrosion-resistant performance, does not contain toxic chemical substances which bring risks to the environment and operators in the formula, is healthy and environment-friendly, and is more suitable for oxidation coloring of pure copper and brass.

The core of the invention lies in the formula components of the pretreatment agent, the pre-blackening agent and the use process. Firstly, copper material pretreatment, namely, oil and rust removal and activation treatment are carried out by adopting a one-step method; then, carrying out pre-blackening treatment by using an alkaline liquid medicine with oxidability to form an initial black film on the surface of the copper material; and finally, using a blackening agent to improve the uniformity and blackening degree of the black film and enhance the stability of the black film.

Compared with other copper material coloring processes in the market at present, the process can greatly reduce the working procedures and improve the process efficiency and the product yield, meanwhile, the process uses a process which does not contain chemical components and dangerous processes harmful to human bodies and atmospheric environment, and meets the requirement of environmental protection.

Detailed Description

The present invention is further described below with reference to specific embodiments, and it should be noted that, without conflict, any combination between the embodiments or technical features described below may form a new embodiment.

Example 1

A treatment process for coloring a black oxide film on a copper surface comprises the following steps:

s1 pretreatment: immersing the copper workpiece into a pretreatment agent, ultrasonically cleaning for 3min at the temperature of 55-60 ℃, and rinsing with clear water to obtain a pretreated copper workpiece;

s2 pre-blackening process: immersing the pre-treated copper workpiece into a pre-blackening agent, soaking for 5min at 65-70 ℃, and rinsing with clear water to obtain a pre-blackened copper workpiece;

s3 blackening step: and (3) soaking the pre-blackened copper workpiece into a blackening agent for 5min at the temperature of 55-60 ℃, rinsing with clear water and drying to obtain the black oxide film-coated copper workpiece.

The pretreatment agent comprises the following components in percentage by mass: 5% of citric acid, 2% of phosphoric acid, 3% of fatty alcohol-polyoxyethylene ether, 1% of coconut oil fatty acid diethanol amide, 1% of thiourea and the balance of deionized water.

The pre-blackening agent consists of the following components in percentage by mass: 2% of sodium persulfate; 15% of sodium hydroxide; the balance of deionized water.

The blackening agent comprises the following components in percentage by mass: 8% of sodium persulfate, 2% of sodium citrate, 2% of sodium polyacrylate, 5% of polyethylene glycol, 1% of copper chloride and the balance of deionized water.

The preparation steps of the pretreatment agent are as follows:

1) weighing the raw materials according to the mass parts for later use;

2) mixing deionized water, citric acid and thiourea, pouring into a stirrer, and stirring for 10-20 minutes at normal temperature and normal pressure;

3) sequentially pouring phosphoric acid, fatty alcohol-polyoxyethylene ether and coconut oil fatty acyl diethanol amine into a mixing and stirring tank, stirring for 1-2 min after adding one component, adding the next component, and dissolving after all the components are added.

The preparation method of the pre-blackening agent comprises the following steps:

1) weighing the raw materials according to the mass parts for later use;

2) and pouring the deionized water, the sodium persulfate and the sodium hydroxide into a stirrer in sequence for mixing, and stirring for 5-10 minutes at normal temperature and normal pressure to obtain the sodium persulfate/sodium hydroxide composite material.

The preparation method of the blackening agent comprises the following steps:

1) weighing the raw materials according to the mass parts for later use;

2) pouring deionized water and sodium persulfate into a stirrer in sequence for mixing, and stirring for 10-20 minutes at normal temperature and normal pressure;

3) sequentially pouring sodium citrate, sodium polyacrylate, copper chloride and polyethylene glycol into a mixing and stirring tank, stirring until the components are completely dissolved after adding one component, adding the next component, and dissolving all the components to obtain the final product.

Example 2

A treatment process for coloring a black oxide film on a copper surface comprises the following steps:

The pretreatment agent comprises the following components in percentage by mass: 3% of oxalic acid, 2% of phosphoric acid, 3% of fatty alcohol-polyoxyethylene ether, 1% of coconut oil fatty acid diethanol amide, 1% of urotropine and the balance of deionized water.

The pre-blackening agent consists of the following components in percentage by mass: 3% of potassium persulfate, 17% of potassium hydroxide and the balance of deionized water.

The blackening agent comprises the following components in percentage by mass: 10% of potassium persulfate, 2% of potassium pyrophosphate, 2% of sodium polyacrylate, 6% of polyethylene glycol, 1% of copper sulfate and the balance of deionized water.

The preparation steps of the pretreatment agent are as follows:

1) weighing the raw materials according to the mass parts for later use;

2) mixing deionized water, oxalic acid and urotropine, pouring into a stirrer, and stirring for 10-20 minutes at normal temperature and normal pressure;

The preparation method of the pre-blackening agent comprises the following steps:

1) weighing the raw materials according to the mass parts for later use;

2) and pouring the deionized water, the potassium persulfate and the potassium hydroxide into a stirrer in sequence for mixing, and stirring for 5-10 minutes at normal temperature and normal pressure to obtain the potassium persulfate/potassium hydroxide composite material.

The preparation method of the blackening agent comprises the following steps:

1) weighing the raw materials according to the mass parts for later use;

2) pouring deionized water and potassium persulfate into a stirrer in sequence for mixing, and stirring for 10-20 minutes at normal temperature and normal pressure;

3) sequentially pouring potassium pyrophosphate, sodium polyacrylate, copper sulfate and polyethylene glycol into a mixing and stirring tank, adding one component, stirring until the component is completely dissolved, adding the next component, and dissolving all the components.

Example 3

A treatment process for coloring a black oxide film on a copper surface comprises the following steps:

The pretreatment agent comprises the following components in percentage by mass: 2% of citric acid, 2% of tartaric acid, 3% of phosphoric acid, 3% of fatty alcohol-polyoxyethylene ether, 2% of coconut oil fatty acid diethanol amide, 1% of thiourea, 1% of urotropine and the balance of deionized water.

The pre-blackening agent consists of the following components in percentage by mass: 3% of ammonium persulfate, 18% of potassium hydroxide and the balance of deionized water.

The blackening agent comprises the following components in percentage by mass: 10% of ammonium persulfate, 2% of sodium citrate, 2% of sodium tripolyphosphate, 1% of sodium polyacrylate, 7% of polyethylene glycol, 1% of copper carbonate and the balance of deionized water.

The preparation steps of the pretreatment agent are as follows:

1) weighing the raw materials according to the mass parts for later use;

2) mixing deionized water, citric acid, tartaric acid, thiourea and urotropine, pouring into a stirrer, and stirring for 10-20 minutes at normal temperature and normal pressure;

The preparation method of the pre-blackening agent comprises the following steps:

1) weighing the raw materials according to the mass parts for later use;

2) and pouring the deionized water, the ammonium persulfate and the potassium hydroxide into a stirrer in sequence for mixing, and stirring for 5-10 minutes at normal temperature and normal pressure to obtain the catalyst.

The preparation method of the blackening agent comprises the following steps:

1) weighing the raw materials according to the mass parts for later use;

2) pouring deionized water and ammonium persulfate into a stirrer in sequence for mixing, and stirring for 10-20 minutes at normal temperature and normal pressure;

3) sequentially pouring sodium citrate, sodium tripolyphosphate, sodium polyacrylate, copper carbonate and polyethylene glycol into a mixing and stirring tank, stirring until one component is completely dissolved after each component is added, adding the next component, and dissolving all the components to obtain the composition.

Example 4

A treatment process for coloring a black oxide film on the surface of brass comprises the following steps:

s1 pretreatment: immersing a brass workpiece into a pretreatment agent, ultrasonically cleaning for 3min at the temperature of 55-60 ℃, and rinsing with clear water to obtain a pretreated brass workpiece;

s2 pre-blackening process: immersing the pre-treated brass workpiece into a pre-blackening agent, soaking for 5min at 65-70 ℃, and rinsing with clear water to obtain a pre-blackened copper workpiece;

s3 blackening step: and (3) immersing the pre-blackened brass workpiece into a blackening agent, soaking for 5min at 55-60 ℃, rinsing with clear water, and drying to obtain the brass workpiece with the black oxide film.

The pretreatment agent comprises the following components in percentage by mass: 4% of citric acid, 3% of phosphoric acid, 4% of fatty alcohol-polyoxyethylene ether, 2% of coconut oil fatty acid diethanol amide, 1% of thiourea and the balance of deionized water.