CN103774159A - Formula of aluminum material acid-washing corrosion inhibitor and preparation method for aluminum material acid-washing corrosion inhibitor - Google Patents

Abstract

The invention discloses a formula of an aluminum pickling corrosion inhibitor and a preparation method thereof. The formula of the aluminum pickling corrosion inhibitor includes: cetyl dimethyl (2-sulfurous acid) Ethylammonium (C20) 10% to 20%, diethylthiourea 4% to 8%, hexamethylenetetramine 10% to 15%, dextrin 2% to 5%, nonylphenol polyoxyethylene ether 5% to 10%, water 50% to 65%; the preparation method of the aluminum pickling corrosion inhibitor comprises the following steps: at normal temperature, according to the mass percentage of the formula, cetyl dimethyl (2- Sulphite) ethylammonium (C20) and nonylphenol polyoxyethylene ether were poured into water, and mechanically stirred for 15 minutes; after stirring evenly, hexamethylenetetramine, diethylthiourea and dextrin were added in sequence, and Continue to stir until it is completely dissolved and mixed evenly, which is the pickling corrosion inhibitor. The invention improves the corrosion inhibition efficiency, has long duration of action, small dosage, is non-toxic and harmless, and has low production cost, and is a green corrosion inhibitor with great application potential.

Description

A kind of formulation and preparation method of aluminum pickling corrosion inhibitor

technical field

The invention belongs to the technical field of aluminum material cleaning, and in particular relates to a formula of an aluminum material pickling corrosion inhibitor and a preparation method thereof.

Background technique

In order to remove scale and corrosion products on the metal surface and restore the heat exchange function of heat exchange equipment, chemical cleaning technology is a convenient and low-cost method. Chemical cleaning is to change insoluble substances into soluble salts through chemical reactions on metal surfaces. In the pickling process, while removing scale and rust, H+ ions will corrode the metal substrate and cause hydrogen embrittlement. Practice has proved that adding pickling corrosion inhibitors during chemical cleaning can greatly weaken the corrosion of the metal substrate , which can both descale and protect metal equipment. Therefore, chemical cleaning corrosion inhibitors are added while cleaning.

Metal aluminum has beautiful appearance, light weight, good thermal conductivity and corrosion resistance (dense oxidation products, strong adhesion), non-toxic oxide corrosion products, and does not pollute the environment. It is widely used in many departments such as aluminum finned condensing equipment, air coolers, condensers, dryers, tankers and piping, etc., such as electric power, aviation, chemical industry, and daily life.

Existing aluminum alloy corrosion inhibitors are divided into oxide film type, precipitation film type and adsorption film corrosion inhibitors from the physical and chemical point of view, such as: dichromate, chromate, phosphite, silicate, benzene, etc. Formate, polyphosphate, arsenic ion, antimony ion, etc. Inorganic substances are used as corrosion inhibitors, such as chromate and nitrite, but such corrosion inhibitors are seriously polluted and restricted. Organic corrosion inhibitor is an important kind of pickling corrosion inhibitor, which improves the pitting corrosion resistance of aluminum alloy in low concentration solution; when its concentration is high, it will cause corrosion of aluminum alloy, and its use concentration is limited .

Sulfuric acid is an extremely common and cheap cleaning agent, which is widely used in daily equipment cleaning. Due to the corrosiveness of sulfuric acid, there is a problem of corrosion on aluminum materials when pickling with sulfuric acid. Therefore, it is necessary to add a special pickling corrosion inhibitor for cleaning aluminum materials.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a formula and preparation method of an aluminum acid pickling corrosion inhibitor, aiming at solving the problem of corrosion of aluminum materials in the process of sulfuric acid pickling.

The embodiment of the present invention is achieved in this way, a formula of aluminum acid pickling corrosion inhibitor, the formula of the aluminum material pickling corrosion inhibitor comprises: cetyl dimethyl (2-sulfurous acid ) ethylammonium (C20) 10% to 20%, diethylthiourea 4% to 8%, hexamethylenetetramine 10% to 15%, dextrin 2% to 5%, nonylphenol polyoxyethylene Ether 5% to 10%, water 50% to 65%.

Another object of the embodiments of the present invention is to provide a method for preparing an aluminum pickling corrosion inhibitor, which includes the following steps:

At room temperature, according to hexadecyldimethyl (2-sulfite) ethylammonium (C20) 10% ~ 20%, diethylthiourea 4% ~ 8%, hexamethylenetetramine 10% ~ 15%, dextrin 2% to 5%, nonylphenol polyoxyethylene ether 5% to 10%, water 50% to 65% by mass, and prepare materials;

Pour hexadecyldimethyl (2-sulfite) ethylammonium (C20) and nonylphenol polyoxyethylene ether into water, and mechanically stir for 15 minutes;

After stirring evenly, add hexamethylenetetramine, diethylthiourea and dextrin in sequence, and continue to stir until they are all dissolved and mixed evenly, it is the pickling corrosion inhibitor.

Further, the method of using the aluminum pickling corrosion inhibitor is: adding the aluminum pickling corrosion inhibitor to a sulfuric acid solution with a concentration of 8% to 15%, and the concentration of the corrosion inhibitor is 1g/L to 3g /L, the temperature is controlled at 20°C to 50°C, and the time for immersing the cleaned metal aluminum is 6h to 12h.

Further, the mass percentage content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 15 %; diethylthiourea 6%; hexamethylenetetramine 12%; dextrin 2%; nonylphenol polyoxyethylene ether 8%; water 57%.

Further, the mass percentage content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 15 %; diethylthiourea 5%; hexamethylenetetramine 13%; dextrin 4%; nonylphenol polyoxyethylene ether 6%; water 57%.

Further, the mass percentage content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20)20 %; diethylthiourea 5%; hexamethylenetetramine 14%; dextrin 3%; nonylphenol polyoxyethylene ether 8%; water 50%.

Further, the mass percentage content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 15 %; diethylthiourea 7%; hexamethylenetetramine 12%; dextrin 2%; nonylphenol polyoxyethylene ether 8%; water 56%.

Further, the mass percent content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 10 %; diethylthiourea 6%; hexamethylenetetramine 10%; dextrin 4%; nonylphenol polyoxyethylene ether 10%; water 60%.

Further, the mass percent content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 10 %; diethylthiourea 5%; hexamethylenetetramine 15%; dextrin 2%; nonylphenol polyoxyethylene ether 10%; water 58%.

Further, the mass percentage content of the chemical components of the pickling corrosion inhibitor in the preparation method of the aluminum pickling corrosion inhibitor can be: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 15 %; diethylthiourea 4%; hexamethylenetetramine 14%; dextrin 3%; nonylphenol polyoxyethylene ether 12%; water 52%.

The formulation and preparation method of the pickling corrosion inhibitor for aluminum material provided by the invention is made by compounding organic and inorganic corrosion inhibitors, which improves the corrosion inhibition efficiency, has long duration of action, small dosage, and is non-toxic and harmless , there is no environmental pollution problem, and the production cost is low. It is a kind of green corrosion inhibitor with great application potential. The method of the invention is simple and easy to operate, and preferably solves the problem of corrosion of aluminum materials in the process of adopting sulfuric acid pickling.

Description of drawings

Fig. 1 is a flowchart of a preparation method of an aluminum pickling corrosion inhibitor provided by an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The application principle of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The formula of the aluminum acid pickling corrosion inhibitor according to the embodiment of the present invention includes: hexadecyldimethyl (2-sulfurous acid) ethyl ammonium (C20) 10% ~ 20%, diethylthiourea 4%-8%, hexamethylenetetramine 10%-15%, dextrin 2%-5%, nonylphenol polyoxyethylene ether 5%-10%, water 50%-65%;

Hexadecyldimethyl (2-sulfite) ethyl ammonium (C20) is a dialkyl quaternary ammonium salt active agent, which contains both long-chain alkyl and sulfite structures, and its sterilization, corrosion inhibition Functions are superior to traditional quaternary ammonium salts.

Hexadecyldimethyl (2-sulfite) ethylammonium (C20) is a high-efficiency biocide, which can kill fungi and algae in the dirt, and also has the function of corrosion inhibition. It is non-toxic and can Biodegradable and has a synergistic effect with other corrosion inhibitors.

Quaternary ammonium surfactants have good penetrating ability and surface wetting effect, and can promote the dissolution of scale during pickling. In addition, they have the function of sterilizing and killing algae, which can greatly speed up the stripping of dirt. It can also be used on metal surfaces. A dense adsorption film is formed, which prolongs the rust-returning time of the metal surface activated by pickling and derusting, and acts as a corrosion inhibitor.

Hexamethylenetetramine is non-toxic and has no peculiar smell. Because there is a large ring in its molecule, when in contact with the metal surface, it will adsorb and form a film on the metal surface. At the same time, it is mixed with diethylthiourea with low toxicity to produce synergistic role, forming an efficient corrosion inhibition effect.

Dextrin is a modified oxidized maltodextrin prepared by using maltodextrin as raw material and hydrogen peroxide. There are carbonyl groups in the structure, which can be adsorbed on the active points of the metal surface or the entire surface to form a protective film and reduce the corrosion of the material.

Nonylphenol polyoxyethylene ether is a non-ionic surfactant, which is relatively stable to water and acid. It has the properties of wetting, emulsification, and diffusion in the cleaning solution, and at the same time increases the hydrophobicity of the protective film. It is used as a composite corrosion inhibitor The ingredients of the agent have a good synergistic effect.

As shown in Figure 1, the preparation method of the aluminum pickling corrosion inhibitor of the embodiment of the present invention comprises the following steps:

S101: At room temperature, according to hexadecyldimethyl (2-sulfite) ethylammonium (C20) 10% ~ 20%, diethylthiourea 4% ~ 8%, hexamethylenetetramine 10% % to 15%, dextrin 2% to 5%, nonylphenol polyoxyethylene ether 5% to 10%, water 50% to 65% by mass, and prepare materials;

S102: Pour hexadecyldimethyl (2-sulfite) ethyl ammonium (C20) and nonylphenol polyoxyethylene ether into water, and mechanically stir for 15 minutes;

S103: After stirring evenly, add hexamethylenetetramine, diethylthiourea, and dextrin in sequence, and continue stirring until they are all dissolved and mixed evenly, which is the pickling corrosion inhibitor.

The method of using the aluminum pickling corrosion inhibitor in the embodiment of the present invention is: adding the aluminum pickling corrosion inhibitor to the sulfuric acid solution with a concentration of 8% to 15%, and the concentration of the corrosion inhibitor is 1g/L ~3g/L, the temperature is controlled at 20°C~50°C, and the time for immersing the cleaned metal aluminum is 6h~12h.

The use effect of the present invention is supplemented in conjunction with the following specific examples:

Example 1:

Pickling corrosion inhibitor chemical composition mass percentage, cetyl dimethyl (2-sulfite) ethyl ammonium (C20) 15%; diethylthiourea 6%; hexamethylenetetramine 12 %; dextrin 2%; nonylphenol ethoxylate 8%; water 57%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above medicaments evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 10%, the consumption of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 2g/L, and the temperature is adjusted to At 40°C, put the cleaned metal aluminum on the test piece holder under the condition of a constant temperature water bath, and immerse it in the pickling solution for 10 hours.

The corrosion rate is 0.07g/(m ² ·h), which is far lower than the national standard of 1.5g/(m ² ·h), and the highest corrosion inhibition rate reaches 97%, indicating that it is a high-performance corrosion inhibitor.

Example 2:

The mass percentage of the chemical components of the pickling corrosion inhibitor:

Cetyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 5%; Hexamethylenetetramine 13%; Dextrin 4%; Nonylphenol polyoxyethylene Ether 6%; Water 57%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above agents evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 12%, the amount of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 1.5g/L, and the temperature is adjusted To 30°C, put the cleaned metal aluminum on the test piece holder under the condition of constant temperature water bath, and immerse in the pickling solution for 8 hours.

The corrosion rate is 0.09g/(m ² ·h), which is far lower than the national standard of 1.5g/(m ² ·h), and the highest corrosion inhibition rate reaches 96%, indicating that it is a high-performance corrosion inhibitor.

Example 3:

The mass percentage of the chemical components of the pickling corrosion inhibitor:

Cetyldimethyl(2-sulfite)ethylammonium (C20) 20%; Diethylthiourea 5%; Hexamethylenetetramine 14%; Dextrin 3%; Nonylphenol polyoxyethylene Ether 8%; Water 50%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above agents evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 15%, the consumption of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 1g/L, and the temperature is adjusted to 50°C, put the cleaned metal aluminum on the test piece holder under the condition of constant temperature water bath, and immerse in the pickling solution for 6 hours.

The corrosion rate is 0.11g/(m ² ·h), far lower than the national standard of 1.5g/(m ² ·h), and the highest corrosion inhibition rate reaches 95%, indicating that it is a high-performance corrosion inhibitor.

Example 4:

The mass percentage of the chemical components of the pickling corrosion inhibitor:

Cetyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 7%; Hexamethylenetetramine 12%; Dextrin 2%; Nonylphenol polyoxyethylene Ether 8%; Water 56%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above medicaments evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 8%, the consumption of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 3g/L, and the temperature is adjusted to At 35°C, put the cleaned metal aluminum on the test piece holder under the condition of a constant temperature water bath, and immerse it in the pickling solution for 9 hours.

The corrosion rate is 0.05g/(m ² ·h), which is far lower than the national standard of 1.5g/(m ² ·h), and the corrosion inhibition rate reaches 98%, indicating that it is a high-performance corrosion inhibitor.

Example 5:

The mass percentage of the chemical components of the pickling corrosion inhibitor:

Cetyldimethyl(2-sulfite)ethylammonium (C20) 10%; Diethylthiourea 6%; Hexamethylenetetramine 10%; Dextrin 4%; Nonylphenol polyoxyethylene Ether 10%; Water 60%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above agents evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 11%, the consumption of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 1g/L, and the temperature is adjusted to At 25°C, put the cleaned metal aluminum on the test piece holder under the condition of a constant temperature water bath, and immerse it in the pickling solution for 8 hours.

The corrosion rate is 0.15g/(m ² ·h), which is far lower than the national standard of 1.5g/(m ² ·h), and the highest corrosion inhibition rate reaches 93%, indicating that it is a high-performance corrosion inhibitor.

Embodiment 6:

The mass percentage of the chemical components of the pickling corrosion inhibitor:

Cetyldimethyl(2-sulfite)ethylammonium (C20) 10%; Diethylthiourea 5%; Hexamethylenetetramine 15%; Dextrin 2%; Nonylphenol polyoxyethylene Ether 10%; Water 58%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above agents evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 12%, the amount of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 2.5g/L, and the temperature is adjusted Put the cleaned metal aluminum on the test piece holder under the condition of constant temperature water bath at 30°C, and immerse in the pickling solution for 12 hours.

The corrosion rate is 0.07g/(m ² ·h), which is far lower than the national standard of 1.5g/(m ² ·h), and the corrosion inhibition rate reaches 97%, indicating that it is a high-performance corrosion inhibitor.

Embodiment 7:

The mass percentage of chemical components of pickling corrosion inhibitor

Cetyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 4%; Hexamethylenetetramine 14%; Dextrin 3%; Nonylphenol polyoxyethylene Ether 12%; Water 52%.

Application method of corrosion inhibitor in sulfuric acid pickling solution:

Mix the above medicaments evenly to obtain a corrosion inhibitor, add it to the sulfuric acid pickling solution, the concentration of the pickling solution is 10%, the consumption of the pickling solution is 1500mL, the addition amount of the corrosion inhibitor is 2g/L, and the temperature is adjusted to 50°C, put the cleaned metal aluminum on the test piece holder under the condition of constant temperature water bath, and immerse in the pickling solution for 10 hours.

The corrosion rate of the present invention is 0.13g/(m ² ·h), which is far lower than the national standard of 1.5%, (m ² ·h), and the corrosion inhibition rate reaches 94%, indicating that it is a high-performance corrosion inhibitor.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. A formula of aluminum material pickling corrosion inhibitor, is characterized in that, the formula of this aluminum material pickling corrosion inhibitor comprises: hexadecyl dimethyl (2-sulfurous acid) ethyl Ammonium (C20) 10% to 20%, diethylthiourea 4% to 8%, hexamethylenetetramine 10% to 15%, dextrin 2% to 5%, nonylphenol polyoxyethylene ether 5% ～10%, water 50%～65%. 2. A preparation method of an aluminum pickling inhibitor, characterized in that the preparation method of the aluminum pickling inhibitor comprises the following steps: At room temperature, according to hexadecyldimethyl (2-sulfite) ethylammonium (C20) 10% ~ 20%, diethylthiourea 4% ~ 8%, hexamethylenetetramine 10% ~ 15%, dextrin 2% to 5%, nonylphenol polyoxyethylene ether 5% to 10%, water 50% to 65% by mass, and prepare materials; Pour hexadecyldimethyl (2-sulfite) ethylammonium (C20) and nonylphenol polyoxyethylene ether into water, and mechanically stir for 15 minutes; After stirring evenly, add hexamethylenetetramine, diethylthiourea and dextrin in sequence, and continue to stir until they are all dissolved and mixed evenly, it is the pickling corrosion inhibitor. 3. the preparation method of aluminum material pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the using method of this aluminum material pickling corrosion inhibitor is: adding aluminum material pickling corrosion inhibitor to In the sulfuric acid solution with a concentration of 8% to 15%, the concentration of the corrosion inhibitor is 1g/L to 3g/L, the temperature is controlled at 20°C to 50°C, and the time to immerse the cleaned metal aluminum is 6h to 12h. 4. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percentage of the preparation method of this aluminum pickling corrosion inhibitor Can be: Cetyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 6%; Hexamethylenetetramine 12%; Dextrin 2%; Nonylphenol Polyoxyethylene ether 8%; water 57%. 5. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percent of the preparation method of this aluminum pickling corrosion inhibitor Can be: Hexadecyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 5%; Hexamethylenetetramine 13%; Dextrin 4%; Nonylphenol Polyoxyethylene ether 6%; water 57%. 6. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percentage of the preparation method of this aluminum pickling corrosion inhibitor Can be: Hexadecyldimethyl(2-sulfite)ethylammonium (C20) 20%; Diethylthiourea 5%; Hexamethylenetetramine 14%; Dextrin 3%; Nonylphenol Polyoxyethylene ether 8%; water 50%. 7. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percentage of the preparation method of this aluminum pickling corrosion inhibitor Can be: Hexadecyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 7%; Hexamethylenetetramine 12%; Dextrin 2%; Nonylphenol Polyoxyethylene ether 8%; water 56%. 8. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percent of the preparation method of this aluminum pickling corrosion inhibitor Can be: Cetyldimethyl(2-sulfite)ethylammonium (C20) 10%; Diethylthiourea 6%; Hexamethylenetetramine 10%; Dextrin 4%; Nonylphenol Polyoxyethylene ether 10%; water 60%. 9. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percent of the preparation method of this aluminum pickling corrosion inhibitor Can be: Cetyldimethyl(2-sulfite)ethylammonium (C20) 10%; Diethylthiourea 5%; Hexamethylenetetramine 15%; Dextrin 2%; Nonylphenol Polyoxyethylene ether 10%; water 58%. 10. the preparation method of aluminum pickling corrosion inhibitor as claimed in claim 2 is characterized in that, the pickling corrosion inhibitor chemical component mass percent of the preparation method of this aluminum pickling corrosion inhibitor Can be: Cetyldimethyl(2-sulfite)ethylammonium (C20) 15%; Diethylthiourea 4%; Hexamethylenetetramine 14%; Dextrin 3%; Nonylphenol Polyoxyethylene ether 12%; water 52%.