阅读说明：本技术 抑垢增亮铝合金碱蚀液及其制备方法 (Scale-inhibiting brightening aluminum alloy alkaline etching solution and preparation method thereof ) 是由 宋志健 喻诚 于 2020-12-04 设计创作，主要内容包括：本发明涉及抑垢增亮铝合金碱蚀液及其制备方法,涉及铝合金阳极氧化前处理技术领域。抑垢增亮铝合金碱蚀液,由60-100g/L的氢氧化钠、50-80g/L的碱蚀剂和水组成；所述碱蚀剂由碳酸钠10-25g/L、磷酸钠15-40g/L和添加剂组成；添加剂由抑垢剂10-20g/L、光亮剂3-6g/L、活性剂1-5g/L和络合剂1-3g/L组成。其制备方法中,采用先配置槽液,向槽液中按比例添加碳酸钠、磷酸钠和水并搅拌均匀,并单独制备添加剂,同时将制得的添加剂加入至上述混合溶液中,既得碱蚀液。(The invention relates to an alkali etching solution for inhibiting scale and brightening aluminum alloy and a preparation method thereof, and relates to the technical field of aluminum alloy anodic oxidation pretreatment. The scale-inhibiting brightening aluminum alloy alkaline etching solution consists of 60-100g/L of sodium hydroxide, 50-80g/L of alkaline etching agent and water; the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive; the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent. The preparation method comprises the steps of preparing a bath solution, adding sodium carbonate, sodium phosphate and water into the bath solution in proportion, uniformly stirring, independently preparing the additive, and adding the prepared additive into the mixed solution to obtain the alkaline etching solution.)

1. The scale-inhibiting brightening aluminum alloy alkaline etching solution is characterized in that: consists of 60-100g/L of sodium hydroxide, 50-80g/L of alkaline etching agent and water;

the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive;

the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent.

2. The scale-inhibiting and brightening aluminum alloy alkaline etching solution as claimed in claim 1, characterized in that: the scale inhibitor is at least one of sodium gluconate, sodium citrate, tetrasodium hydroxyethylidene diphosphate, trisodium aminotrimethyl phosphonate, sodium heptonate and sorbitol.

3. The scale-inhibiting and brightening aluminum alloy alkaline etching solution as claimed in claim 1, characterized in that: the brightener is one or more of sodium alginate, sodium lignosulphonate and alkylphenol polyoxyethylene.

4. The scale-inhibiting and brightening aluminum alloy alkaline etching solution as claimed in claim 1, characterized in that: the active agent is sodium benzoate.

5. The scale-inhibiting and brightening aluminum alloy alkaline etching solution as claimed in claim 1, characterized in that: the complexing agent is one or more of hydroxyl carboxylate, ammonia-carboxyl complex and polyhydric alcohol.

6. A preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution as claimed in any one of claims 1 to 5, characterized by comprising the following steps: the method comprises the following steps:

(1) preparing a bath solution: adding sodium hydroxide and water into a reaction kettle in proportion, and stirring until the sodium hydroxide is completely dissolved;

(2) adding sodium carbonate, sodium phosphate and water into the tank liquor in proportion and uniformly stirring;

(3) preparing an additive: adding the weighed scale inhibitor, brightener, activator and complexing agent into a dryer, and rotationally stirring for 1-3 hours at the temperature of 25-35 ℃ until the mixture is uniformly mixed;

(4) and (3) adding the additive prepared in the step (3) into the solution prepared in the step (2), and stirring at 20-40 ℃ until the additive is uniformly mixed to obtain the alkaline etching solution.

Technical Field

The invention relates to an aluminum alloy alkaline etching solution for inhibiting scale and brightening and a preparation method thereof, belonging to the technical field of aluminum alloy anodic oxidation pretreatment.

Background

Aluminum profiles are mostly subjected to anodic oxidation or electrolytic coloring treatment, and an alkaline etching process in pretreatment is a key step for obtaining a good surface. After the alkaline etching treatment, the natural oxide film on the surface of the aluminum profile can be dissolved to expose the matrix metal, the surface of the aluminum profile is activated, and the alkaline etching solution has strong etching capability at a certain concentration and temperature, so that the defects of extrusion rough lines and the like on the surface can be reduced or eliminated, and a smooth surface is obtained; the alkaline solution has certain oil removing and degreasing capability, and the oil stain can be further removed and the surface can be purified by alkaline etching the deoiled aluminum material; in addition, some aluminum profiles requiring dark surface can obtain sand surfaces with different thicknesses after being added with certain alkali etching additives, and the color is uniform, soft and beautiful after oxidation coloring.

However, when the aluminum alloy is treated by the existing aluminum alloy alkaline etching solution, oil stains and natural oxidation films still remain on the surface of the aluminum alloy, and the surface of the treated aluminum alloy is not smooth enough, so that the subsequent oxidation is greatly influenced, and the loss and waste of the aluminum alloy and the over consumption of alkali are caused.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a scale-inhibiting and brightening aluminum alloy alkaline etching solution and a preparation method thereof, and the specific technical scheme is as follows:

the scale-inhibiting brightening aluminum alloy alkaline etching solution consists of 60-100g/L of sodium hydroxide, 50-80g/L of alkaline etching agent and water;

the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive;

the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent.

Further, the scale inhibitor is at least one of sodium gluconate, sodium citrate, tetrasodium hydroxyethylidene diphosphate, trisodium aminotrimethyl phosphonate, sodium heptonate and sorbitol. The sodium gluconate also has strong complexing effect and inhibits the hydrolysis of aluminum ions in the alkali liquor to form precipitates; the sodium citrate is used as a corrosion inhibitor and a complexing agent, so that the cleaning speed of attachments on the surface of the aluminum alloy is accelerated, and the corrosion of sulfuric acid to the aluminum alloy is weakened.

Further, the brightening agent is one or more of sodium alginate, sodium lignosulphonate and alkylphenol polyoxyethylene.

Further, the active agent is sodium benzoate. Can accelerate the oil removal of the surface of the aluminum profile.

Further, the complexing agent is one or more of hydroxyl carboxylate, ammonia carboxyl complex and polyhydric alcohol.

The scale-inhibiting brightening aluminum alloy alkaline etching solution disclosed by the invention consists of sodium hydroxide, an alkaline etching agent and water, micro-etching pits on the surface of an aluminum piece are enlarged by utilizing the strong corrosivity of the alkaline solution to form a complete and uniform rough sand surface, the corrosivity of the alkaline solution on the aluminum alloy is enhanced by adding the alkaline etching agent, the reaction speed is accelerated, and the scale inhibitor is added into the alkaline etching agent, so that aluminum ions can be complexed, the upper limit of aluminum ion control of the alkaline etching solution is effectively improved, the aluminum dissolving amount of an alkaline etching tank is increased, and scaling is inhibited; the brightener can improve the glossiness of the processed workpiece; the surfactant is used for accelerating oil removal, and meanwhile, the surfactant is used for inhibiting corrosion by utilizing the lubricating and adsorbing effects of the surfactant, so that the crystal growth is prevented; the complexing agent can inhibit the generation of aluminum hydroxide precipitate, and can be converted into soluble complex anions, and meanwhile, the allowable dissolving amount of aluminum ions is increased.

The preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution comprises the following steps:

(1) preparing a bath solution: adding sodium hydroxide and water into a reaction kettle in proportion, and stirring until the sodium hydroxide is completely dissolved;

(2) adding sodium carbonate, sodium phosphate and water into the tank liquor in proportion and uniformly stirring;

(3) preparing an additive: adding the weighed scale inhibitor, brightener, activator and complexing agent into a dryer, and rotationally stirring for 1-3 hours at the temperature of 25-35 ℃ until the mixture is uniformly mixed;

(4) and (3) adding the additive prepared in the step (3) into the solution prepared in the step (2), and stirring at 20-40 ℃ until the additive is uniformly mixed to obtain the alkaline etching solution.

According to the preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution, by means of a gradual adding method and reasonable design of a charging sequence, the dissolving performance of various substances can be improved, the possibility of particle agglomeration can be avoided, and the surface protection function of the alkaline etching solution is remarkably improved; meanwhile, the independently prepared additive can improve the activity of each component in the additive, so that the prepared alkaline etching solution can effectively carry out alkaline etching treatment on the aluminum profile, the surface of the aluminum profile is smooth and flat, insufficient corrosion reaction or over corrosion cannot be generated, the aluminum loss and the alkali consumption are reduced, meanwhile, aluminum ion scaling can be prevented, sediment which is difficult to treat cannot be generated in the bath solution, the concentration of aluminum ions in the bath solution can be kept stable for a long time, and the service cycle of the bath solution is long.

The invention has the beneficial effects that:

1. the scale-inhibiting brightening aluminum alloy alkaline etching solution disclosed by the invention consists of sodium hydroxide, an alkaline etching agent and water, micro-etching pits on the surface of an aluminum piece are enlarged by utilizing the strong corrosivity of the alkaline solution to form a complete and uniform rough sand surface, the corrosivity of the alkaline solution on the aluminum alloy is enhanced by adding the alkaline etching agent, the reaction speed is accelerated, and the scale inhibitor is added into the alkaline etching agent, so that aluminum ions can be complexed, the upper limit of aluminum ion control of the alkaline etching solution is effectively improved, the aluminum dissolving amount of an alkaline etching tank is increased, and scaling is inhibited; the brightener can improve the glossiness of the processed workpiece; the surfactant is used for accelerating oil removal, and meanwhile, the surfactant is used for inhibiting corrosion by utilizing the lubricating and adsorbing effects of the surfactant, so that the crystal growth is prevented; the complexing agent can inhibit the generation of aluminum hydroxide precipitate, and can be converted into soluble complex anions, and meanwhile, the allowable dissolving amount of aluminum ions is increased.

2. According to the preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution, by means of a gradual adding method and reasonable design of a charging sequence, the dissolving performance of various substances can be improved, the possibility of particle agglomeration can be avoided, and the surface protection function of the alkaline etching solution is remarkably improved; meanwhile, the independently prepared additive can improve the activity of each component in the additive, so that the prepared alkaline etching solution can effectively carry out alkaline etching treatment on the aluminum profile, the surface of the aluminum profile is smooth and flat, insufficient corrosion reaction or over corrosion cannot be generated, the aluminum loss and the alkali consumption are reduced, meanwhile, aluminum ion scaling can be prevented, sediment which is difficult to treat cannot be generated in the bath solution, the concentration of aluminum ions in the bath solution can be kept stable for a long time, and the service cycle of the bath solution is long.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The scale-inhibiting brightening aluminum alloy alkaline etching solution consists of 60-100g/L of sodium hydroxide, 50-80g/L of alkaline etching agent and water;

the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive;

the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent.

Wherein the scale inhibitor is at least one of sodium gluconate, sodium citrate, tetrasodium hydroxyethylidene diphosphate, trisodium aminotrimethyl phosphonate, sodium heptonate and sorbitol.

Wherein the brightener is one or more of sodium alginate, sodium lignosulphonate and alkylphenol polyoxyethylene.

Wherein the activator is sodium benzoate.

Wherein the complexing agent is one or more of hydroxyl carboxylate, ammonia-carboxyl complex and polyalcohol.

Examples of the invention are further illustrated in the following by means of a number of examples.

Example 1

The scale-inhibiting and brightening aluminum alloy alkaline etching solution consists of 70g/L sodium hydroxide, 60g/L alkaline etching agent and water;

the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive;

the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent.

The scale inhibitor is sodium gluconate, sodium citrate and sorbitol;

the brightener is sodium alginate and sodium lignosulfonate;

the active agent is sodium benzoate;

the complexing agent is a hydroxycarboxylic acid salt and an ammonia carboxylic acid complex.

The preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution comprises the following steps:

(1) preparing a bath solution: adding sodium hydroxide and water into a reaction kettle in proportion, and stirring until the sodium hydroxide is completely dissolved;

(2) adding sodium carbonate, sodium phosphate and water into the tank liquor in proportion and uniformly stirring;

(3) preparing an additive: adding the weighed scale inhibitor, brightener, activator and complexing agent into a dryer, and rotationally stirring for 1h at the temperature of 25-35 ℃ until the materials are uniformly mixed;

(4) and (3) adding the additive prepared in the step (3) into the solution prepared in the step (2), and stirring at 20-40 ℃ until the additive is uniformly mixed to obtain the alkaline etching solution.

Example 2

The scale-inhibiting brightening aluminum alloy alkaline etching solution consists of 80g/L sodium hydroxide, 70g/L alkaline etching agent and water;

the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive;

the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent.

The scale inhibitor is sodium gluconate and sodium citrate;

the brightener is sodium alginate;

the active agent is sodium benzoate;

the complexing agent is a hydroxycarboxylic acid salt.

The preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution comprises the following steps:

(1) preparing a bath solution: adding sodium hydroxide and water into a reaction kettle in proportion, and stirring until the sodium hydroxide is completely dissolved;

(2) adding sodium carbonate, sodium phosphate and water into the tank liquor in proportion and uniformly stirring;

(3) preparing an additive: adding the weighed scale inhibitor, brightener, activator and complexing agent into a dryer, and rotationally stirring for 2 hours at the temperature of 25-35 ℃ until the materials are uniformly mixed;

(4) and (3) adding the additive prepared in the step (3) into the solution prepared in the step (2), and stirring at 20-40 ℃ until the additive is uniformly mixed to obtain the alkaline etching solution.

Example 3

The scale-inhibiting brightening aluminum alloy alkaline etching solution consists of 90g/L sodium hydroxide, 75g/L alkaline etching agent and water;

the alkaline etching agent consists of 10-25g/L of sodium carbonate, 15-40g/L of sodium phosphate and an additive;

the additive consists of 10-20g/L of scale inhibitor, 3-6g/L of brightener, 1-5g/L of activator and 1-3g/L of complexing agent.

The scale inhibitor is sodium gluconate, sodium heptonate and sorbitol;

the brightener is sodium lignosulfonate and alkylphenol polyoxyethylene;

the active agent is sodium benzoate;

the complexing agent is a hydroxycarboxylic acid salt.

The preparation method of the scale-inhibiting and brightening aluminum alloy alkaline etching solution comprises the following steps:

(1) preparing a bath solution: adding sodium hydroxide and water into a reaction kettle in proportion, and stirring until the sodium hydroxide is completely dissolved;

(2) adding sodium carbonate, sodium phosphate and water into the tank liquor in proportion and uniformly stirring;

(3) preparing an additive: adding the weighed scale inhibitor, brightener, activator and complexing agent into a dryer, and rotationally stirring for 2.5 hours at the temperature of 25-35 ℃ until the materials are uniformly mixed;

(4) and (3) adding the additive prepared in the step (3) into the solution prepared in the step (2), and stirring at 20-40 ℃ until the additive is uniformly mixed to obtain the alkaline etching solution.

Comparative example 1

At 25 ℃, aluminum profiles are respectively put into the alkaline etching solution containing the additive and marked as No. 1 and the alkaline etching solution not containing the additive and marked as No. 2 for alkaline etching treatment, and the film weight of the two samples after alkaline etching and light-emitting is tested, and the test results are shown in the following table 1:

the above table shows that the surfaces of the two samples are relatively bright, the film layer weight loss of the 2# sample is relatively high, and the film layer weight loss of the 1# sample is relatively low, which indicates that the alkaline etching solution added with the additive has low corrosivity on the aluminum profile and has a good light-emitting effect.

It is noted that, in this document, relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.