A kind of carbon steel rust remover and its preparation method and application

Abstract

The invention discloses a carbon steel rust remover and its preparation method and application, and relates to the technical field of metal rust removal and cleaning, wherein the rust remover comprises 30%-45% of organic acid, 1%-4% of thiol PEG amine, 0.5%-1% of quaternary ammonium salt, 1%-2% of organic solvent and surplus deionized water, based on the total mass of the rust remover. In the present invention, the sulfhydryl and amino groups in the thiol PEG amine molecule form a structurally stable coordination chelate film on the surface of a metal matrix, which can inhibit the excessive corrosion of aminosulfonic acid to a metal matrix; the chelate film formed by the thiol PEG amine contains a large amount of oxygen atoms, and under the action of hydrogen bonds, it is combined with quaternary ammonium salt to significantly improve the corrosion potential, and further enhance the corrosion resistance of the metal; the rust remover of the present invention can be used to remove rust and clean rusted carbon steel in a short time, and the effect is good, and the rust removal process will not damage the metal body.

Description

Technical Field

[0001] The invention belongs to the technical field of rust removal, and in particular relates to a carbon steel rust remover and a preparation method and application thereof. Background Art

[0002] The corrosion of metal materials has always troubled people's production and life, not only causing great economic losses but also bringing potential safety hazards. It is a convenient and quick method to remove rust from metals by rust removers. At present, the methods of pickling with hydrochloric acid, sulfuric acid, phosphoric acid or several composite acids are commonly used, but the above-mentioned components are mostly strong acids, which are easy to produce acid mist, which will cause harm to the operator. At the same time, the acidity is too strong and will also corrode the surface of steel, causing the mechanical strength of the material to decrease. It is also easy to rust after rust removal, which brings many inconveniences to production. It is also a common means to use organic acids to replace inorganic acids for rust removal. Chinese invention patent CN109504975A ​​discloses a rust remover that replaces hydrochloric acid, which is composed of composite organic acids, polymethacrylic acid and various auxiliary agents and activators. The formula involves various organic reagents, and the preparation process is complicated and inconvenient to use. Therefore, from the perspective of practicality, a rust remover with easy access to raw materials, simple preparation process and convenient operation is needed. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a rust remover and a preparation method thereof, which achieves the purpose of rust removal and rust prevention in a shorter time under normal temperature conditions. The rust remover has the characteristics of simple preparation process, good rust removal effect and easy operation.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A carbon steel rust remover comprises 30%-45% of an organic acid, 1%-4% of a mercapto PEG amine, 0.5%-1% of a quaternary ammonium salt, 1%-2% of an organic solvent and the balance of deionized water, based on the total mass of the rust remover.

[0006] More preferably, the rust remover comprises 38%-42% of organic acid, 2%-3% of mercapto PEG amine, 0.6%-0.8% of quaternary ammonium salt, 1%-2% of organic solvent and the balance of deionized water, based on the total mass of the rust remover.

[0007] In the present invention, the organic acid is selected from one or more of sulfamic acid, tribromoacetic acid, citric acid, oxalic acid, glycolic acid, and phytic acid;

[0008] In the present invention, the organic solvent is selected from one or more of ethanol, n-propanol, and isopropanol;

[0009] In the present invention, the structural formula of the thiol PEG amine is Where n is the degree of polymerization, ranging from 8 to 226;

[0010] In the present invention, the molecular weight of the thiol PEG amine is preferably 400-10000, preferably 600-2000.

[0011] In the present invention, the quaternary ammonium salt is a compound formed by replacing four hydrogen atoms in the ammonium ion with hydrocarbon groups, with the general formula R4NX, where R is a combination of methyl, ethyl, and propyl, and X is Cl - Br - One of them.

[0012] The present invention also provides a method for preparing a carbon steel rust remover, comprising the following steps: dissolving an organic acid in deionized water and stirring, then dripping an organic solvent, and then adding mercapto PEG amine and a quaternary ammonium salt into the organic acid solution and stirring evenly to prepare the rust remover.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The present invention adopts aminosulfonic acid, an organic strong acid, to replace traditional hydrochloric acid, which has the advantages of being non-volatile and low in toxicity, and thus will not generate acid mist, thereby enhancing the safety of the rust remover.

[0015] 2. The thiol and amino groups in the thiol PEG amine molecules form a structurally stable coordination chelate film on the surface of the metal matrix, which can inhibit the excessive corrosion of the metal matrix by aminosulfonic acid; the chelate film formed by the thiol PEG amine contains a large number of oxygen atoms, which cooperates with the quaternary ammonium salt under the action of hydrogen bonds, significantly improving the corrosion potential and further enhancing the corrosion resistance of the metal.

[0016] 3. The raw materials of rust remover are easy to obtain and prepare, and the rust removal process is simple to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Macroscopic and metallographic images of the 20# carbon steel specimen before and after rust removal in Example 1 DETAILED DESCRIPTION

[0018] The present invention is further described below through the accompanying drawings and specific embodiments. The embodiments of the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0019] Raw material information: Aminosulfonic acid: Aladdin, purity 99%; Mercapto PEG amine: Aladdin, substitution rate > 90%; Tetramethylammonium chloride: Aladdin, analytical grade; Tetramethylammonium bromide: Aladdin, analytical grade; Tetraethylammonium chloride: Aladdin, analytical grade; Dimethyldipropylammonium chloride: Aladdin, analytical grade; Ethanol: Aladdin, purity > 99.8%; 20# carbon steel: low alloy steel containing 0.17%-0.23% carbon, 0.17%-0.37% silicon, and 0.35%-0.65% manganese; 10# carbon steel: low alloy steel containing 0.07%-0.13% carbon, 0.17%-0.37% silicon, and 0.35%-0.65% manganese.

[0020] Equipment information: Electronic analytical balance: Mettler Toledo, model ME203, graduation value 0.001g. Metallographic microscope: Zeiss, Germany, model Lab.a1, eyepiece ×10, objective lens ×5, ×10, ×20, ×50, etc. The actual magnification is the product of the magnification of the eyepiece and the objective lens used.

[0021] Characterization method: Weighing: First, level the electronic analytical balance (adjust the level bubble to the middle) and calibrate it, dry the metal test piece and place weighing paper on the balance tray, weigh the test piece before and after rust removal, accurate to 0.01g, and calculate the mass difference before and after rust removal. Morphology observation: Adjust the light of the metallographic microscope to make the field of view bright, use a 5x objective lens, adjust the coarse focus knob and the fine focus knob to obtain a clear magnified image and take a picture, and finally move the stage to take pictures of other parts of the sample.

[0022] [Example 1]

[0023] Prepare 100g of rust remover. Based on the total mass of the rust remover, dissolve 40% aminosulfonic acid in deionized water and 1% ethanol, then add 2% thiol PEG amine (molecular weight 1000) and 0.8% tetramethylammonium chloride into the aminosulfonic acid solution and stir to prepare the solution.

[0024] Take rusty 20# carbon steel test pieces, weigh them, take photos and record them, then soak them in the above rust remover for 10 minutes. During the soaking process, use a soft brush to gently brush off the surface rust. After the rust removal operation is completed, use clean water and alcohol to clean the test pieces in turn. After drying, weigh them again and take photos and record them. The rust removal rate is estimated by observing the rust removal effect on the surface of the test piece (the complete removal of surface rust is recorded as 100%). Finally, the rust-removed test pieces are placed in the air for 14 days to observe the rust recurrence.

[0025] [Example 2-9]

[0026] According to the raw materials and composition required in Table 1 and referring to the preparation method in Example 1, 100 g of rust remover was prepared, and the test pieces of the given materials in Table 1 were rust-removed according to the treatment method in Example 1 and the results were recorded.

[0027] Table 1 Example Rust Remover Raw Material Composition

[0028]

[0029]

[0030] [Comparative Examples 1-3]

[0031] The 20# carbon steel test piece was rust-removed according to the method in Example 1, except that: in Comparative Example 1, a short-chain organic substance containing thiol and amino groups, cysteine ​​(HSCH2CH(NH2)COOH), was used to replace the thiol PEG amine in the rust remover; in Comparative Example 2, an aliphatic lower thiol, ammonium thioglycolate (HSCH2COONH4), was used to replace the thiol PEG amine in the rust remover; in Comparative Example 3, no thiol PEG amine was used, and the rust remover was prepared with only 40% aminosulfonic acid, 2.8% tetramethylammonium chloride, 1.4% ethanol and the remainder deionized water.

[0032] The test pieces after rust removal in the above examples and comparative examples were weighed and photographed, and the results are shown in Table 2. The morphology of the test piece before and after rust removal in Example 1 is as follows: Figure 1 shown.

[0033] Table 2 Rust removal of each embodiment and comparative example

[0034]

[0035] Based on the results of the above embodiments 1-9, the rust remover proposed by the present invention can effectively remove the rust on the surface of carbon steel, and the rust removal rate can reach up to 100%. It can be effectively inhibited from rusting after long-term exposure to air. It can be seen that the components such as mercapto PEG amine and quaternary ammonium salt in the rust remover form an effective protective film on the surface of the metal body, which plays a good anti-rust effect. The results of comparative examples 1 and 2 show that compared with the rust remover composed of short-chain molecules such as cysteine ​​and ammonium thioglycolate, the long-chain mercapto PEG amine can form a more stable coordination chelate film on the metal surface, and the hydrogen bonding effect of a large number of ordered and dense oxygen atoms on the membrane surface and the quaternary ammonium salt is more obvious, which significantly improves the composite synergistic effect of mercapto PEG amine and quaternary ammonium salt, and further protects the metal. According to the results of comparative example 3, although the rust remover without mercapto PEG amine can play a certain rust removal effect, the rusting situation is significant. The results show that mercapto PEG amine plays a significant role in inhibiting rusting.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and additions without departing from the method of the present invention. These improvements and additions should also be regarded as the scope of protection of the present invention.

Claims

1. A carbon steel rust remover, characterized in that: The rust remover comprises 30%-45% of organic acid, 1%-4% of mercapto PEG amine, 0.5%-1% of quaternary ammonium salt, 1%-2% of organic solvent and the balance of deionized water. Based on the total mass of the rust remover, the structural formula of the mercapto PEG amine is Where n is the degree of polymerization, ranging from 8-226.

2. The carbon steel rust remover according to claim 1, characterized in that: The rust remover comprises 38%-42% of organic acid, 2%-3% of mercapto PEG amine, 0.6%-0.8% of quaternary ammonium salt, 1%-2% of organic solvent and the balance of deionized water, based on the total mass of the rust remover.

3. The carbon steel rust remover according to claim 1, characterized in that: The organic acid is selected from one or more of sulfamic acid, tribromoacetic acid, citric acid, oxalic acid, glycolic acid and phytic acid.

4. The carbon steel rust remover according to any one of claims 1 to 3, characterized in that: The organic solvent is selected from one or more of ethanol, n-propanol and isopropanol.

5. The carbon steel rust remover according to any one of claims 1 to 3, characterized in that: The molecular weight of the thiol PEG amine is 400-10000.

6. The carbon steel rust remover according to any one of claims 1 to 3, characterized in that: The molecular weight of the mercapto PEG amine is 600-2000.

7. The carbon steel rust remover according to any one of claims 1 to 3, characterized in that: The quaternary ammonium salt is a compound formed by replacing the four hydrogen atoms in the ammonium ion with hydrocarbon groups, with the general formula R4NX, where R is a combination of methyl, ethyl, and propyl, and X is Cl - Br - One of them.

8. The method for preparing the carbon steel rust remover according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: dissolving an organic acid in deionized water and stirring the solution, then dropping an organic solvent, and then adding mercapto PEG amine and a quaternary ammonium salt into the organic acid solution and stirring the solution evenly to prepare the rust remover.

Images