An environment-friendly neutral rust remover, its preparation method and its usage method

Abstract

The present invention relates to a kind of environment-friendly neutral rust remover, its preparation method and its application method, its composition is made up of the following raw materials in percentage by weight: stripper 20-30%;Dispersant 8-15%;Compound corrosion inhibitor 3.5-6%;pH adjusting agent 8-10%;The balance is pure water;The stripper is made up of hydroxide, hydroxyl compound mixture and organic acid;The dispersant is made up of polycarboxylic acid type compound, sodium salt and activating agent;The compound corrosion inhibitor is made up of hexamethylenetetramine, main corrosion inhibitor and inorganic salt;The pH adjusting agent is sodium citrate or / and sodium carbonate. The object of the present invention is to design a kind of environment-friendly neutral rust remover, so that the base liquid after the rust remover is diluted with water is neutral, has weak corrosiveness to workpiece surface and treatment tank, has anti-precipitation and the function of protecting workpiece matrix, can make it have the function of degreasing by adding water-based solvent simultaneously, improve rust removal efficiency, work waste liquid treatment cost is low and environmentally friendly, has higher economic benefit.

Description

Technical Field

[0001] The present invention relates to the technical field of rust removers, and in particular to an environmentally friendly neutral rust remover, a preparation method thereof and a use method thereof. Background Art

[0002] When the metal surface is exposed to air for a long time, an oxidation reaction will occur and rust will form on the surface, which will reduce its mechanical properties such as strength, plasticity, and toughness, and will also destroy the metal's geometric shape and shorten the service life of the equipment. Therefore, it is necessary to remove the rust layer on the metal surface through rust removal, and then perform anti-rust treatment such as electroplating and painting.

[0003] Traditional rust removal processes generally use inorganic acids such as industrial hydrochloric acid and industrial sulfuric acid for rust removal. Although the cost is low, these rust removers are highly corrosive and can easily cause "hydrogen embrittlement" in workpieces. In addition, the waste liquid after rust removal is highly polluting to the environment and the cost of waste liquid treatment is high. Adding these rust removers to the treatment tank using a built-bath rust removal method can easily corrode the treatment tank. At the same time, it is also subject to regulations such as the "Regulations on the Management of Precursor Chemicals", which limits its scope of application. Summary of the Invention

[0004] In order to overcome the shortcomings of the background technology, the purpose of the present invention is to design an environmentally friendly neutral rust remover, a preparation method and a use method thereof, wherein the rust remover mainly includes a stripping agent, a dispersant, a composite corrosion inhibitor, a pH regulator and pure water; the base liquid of the rust remover after being diluted with water is neutral, has weak corrosiveness to the workpiece surface and the treatment tank, has the function of preventing precipitation and protecting the workpiece substrate, and at the same time, by adding a water-based solvent, it has the function of removing oil stains, thereby improving the rust removal efficiency, and the working waste liquid treatment cost is low and environmentally friendly, with high economic benefits.

[0005] The technical solution adopted by the present invention is: an environmentally friendly neutral rust remover, which is composed of the following raw materials in the following weight percentages: 20-30% of a stripping agent; 8-15% of a dispersant; 3.5-6% of a composite corrosion inhibitor; 8-10% of a pH regulator; and the remainder being pure water; the stripping agent is composed of a hydroxide, a hydroxyl compound mixture and an organic acid; the dispersant is composed of a polycarboxylic acid compound, a sodium salt and an activator; the composite corrosion inhibitor is composed of hexamethylenetetramine, a main corrosion inhibitor and an inorganic salt; and the pH regulator is sodium citrate and / or sodium carbonate.

[0006] Furthermore, the invention also includes 3-5% of a water-based solvent; the water-based solvent is composed of one or more of propylene glycol, isopropyl alcohol, and monomethyl diethylene glycol ether.

[0007] Furthermore, the hydroxide is sodium hydroxide and / or potassium hydroxide, the hydroxy compound mixture is one or more of hydroxyethylidene diphosphonic acid, disodium hydroxyethylidene diphosphate, tetrasodium hydroxyethylidene diphosphate, and tetrasodium ethylenediaminetetraacetic acid, and the organic acid is isooctanoic acid and / or oxalic acid.

[0008] Furthermore, the hydroxide is preferably sodium hydroxide, the hydroxy compound mixture is preferably hydroxyethylidene diphosphonic acid and ethylenediaminetetraacetic acid tetrasodium salt, and the organic acid is preferably isooctanoic acid.

[0009] Furthermore, the polycarboxylic acid compound is composed of one or more of polyacrylic acid, benzalkonium chloride and polydimethyldiallylammonium chloride, the sodium salt is sodium gluconate and / or sodium chloride, and the active agent is fatty alcohol polyoxyethylene ether (N=9) and / or polyethylene glycol.

[0010] Furthermore, the polycarboxylic acid compound is preferably polyacrylic acid, the sodium salt is preferably sodium gluconate and sodium chloride, and the active agent is preferably fatty alcohol polyoxyethylene ether (N=9).

[0011] Furthermore, the main corrosion inhibitor is one or more of sodium benzoate, benzotriazole, and dodecanedioic acid, and the inorganic salt is one or more of sodium fluoride, sodium nitrite, and ammonium molybdate.

[0012] Furthermore, the main corrosion inhibitor is preferably sodium benzoate and benzotriazole, and the inorganic salt is preferably sodium fluoride.

[0013] The present invention adopts the above technical solution to produce a colorless to light yellow transparent liquid with a pH value of 6.0, a slightly pungent odor, and a density of 1.20±0.05g / cm3 at standard atmospheric pressure. 3 , and can be dissolved in water in any ratio;

[0014] The mass ratio of the hydroxide, hydroxyl compound mixture and organic acid in the stripping agent is 1-2.2:2.8-3.5:0.7-2.3, and the sodium hydroxide, hydroxyethylidene diphosphonic acid and ethylenediaminetetraacetic acid tetrasodium salt in the stripping agent have a chelating effect, which dissolves and peels off the rust layer and impurity layer; the mass ratio of the polycarboxylic acid compound, sodium salt and activator in the dispersant is 3.2-5:1-2:1.8-3.4, and the polyacrylic acid in the dispersant has a scale inhibition effect, which prevents the fallen rust from being redeposited on the workpiece surface; the hexamethylenetetramine in the composite corrosion inhibitor The mass ratio of the main corrosion inhibitor and the inorganic salt is 1-3:0.6-2:0.5-1.8, and the hexamethylenetetramine, sodium benzoate and benzotriazole components in the composite corrosion inhibitor have corrosion inhibition effects, avoiding excessive dissolution of the workpiece matrix and protecting the workpiece matrix; the sodium citrate component in the pH regulator has a chelating effect on metal ions such as Ca, Mg, and Fe, which increases the rust removal ability and adjusts the pH value of the solution, thereby reducing the cost of waste liquid treatment; the propylene glycol in the water-based solvent can dissolve oil stains on the surface of the rusted workpiece, thereby improving the rust removal effect, and the water-based solvent can be added as needed.

[0015] The technical solution of the preparation method adopted by the present invention is: comprising the following steps:

[0016] (1) Prepare the required weight of raw materials according to the percentage contained;

[0017] (2) Pour part of the water into the mixing barrel first, and then add the stripping agent, dispersant, and composite corrosion inhibitor into the mixing barrel in sequence;

[0018] (3) After stirring the reaction in a stirring tank for 1 to 2 minutes, add a pH adjuster and water until the liquid level reaches the specified scale line and the pH value of the sampled stock solution is 5.7 to 6.3;

[0019] (4) After stirring for another 8 to 20 minutes, the stock solution is diluted to volume, bottled, and packaged.

[0020] By adopting the above technical solution, the reaction rate is accelerated by adding a certain amount of stripping agent, dispersant and composite corrosion inhibitor into the stirring barrel. If a water-based solvent is required, it is added into the stirring barrel at the same time.

[0021] The pH value is then adjusted to 6.0 using a pH regulator, thereby meeting large-scale production and market needs.

[0022] The technical solution of the method of use adopted by the present invention is that it can directly wipe the surface of the workpiece to remove rust or build a bath to remove rust, and the bath removal includes the following steps:

[0023] (1) Pour the stock solution into a treatment tank and dilute it with water to obtain a solution with a stock solution content of 10% to 20% and a pH value of 6.5 to 7.2;

[0024] (2) Adjust the solution temperature to 20-80°C;

[0025] (3) Immerse the rusted workpiece in the solution for 5 to 30 minutes and then remove it to complete the rust removal;

[0026] By adopting the above technical solution, when it is necessary to remove rust from the surface of a workpiece, the stock solution is directly applied to the rusted area and wiped; in the process of building the bath, the stock solution ratio concentration is determined according to the degree of rust on the workpiece surface. For workpieces with slight rust, rust removal is carried out according to a solution with a stock solution content of 10%, and for workpieces with heavy rust, rust removal is carried out according to a solution with a stock solution content of 20%; the present invention significantly improves the rust removal speed under the conditions of heating and ultrasonic-assisted cleaning, and the optimal rust removal temperature is 65°C, but in an environment exceeding 80°C, the present invention is likely to lose its rust removal function. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited thereto. The following percentages all represent mass percentages.

[0028] Example 1

[0029] An environmentally friendly neutral rust remover, comprising the following raw materials in the following weight percentages:

[0030] Sodium hydroxide 5%, disodium hydroxyethylidene diphosphate 9%, tetrasodium ethylenediaminetetraacetic acid 7%, 2-ethylhexanoic acid 3%, polyacrylic acid 4.5%, sodium gluconate 0.8%, sodium chloride 0.8%, fatty alcohol polyoxyethylene ether (N=9) 3%, hexamethylenetetramine 1.5%, sodium benzoate 1.2%, benzotriazole 1.2%, sodium fluoride 0.8%, sodium citrate 9.5%, and the balance is pure water;

[0031] The preparation method is:

[0032] (1) Pour water into a stirring barrel, and add sodium hydroxide, disodium hydroxyethylidene diphosphate, tetrasodium ethylenediaminetetraacetic acid, isooctanoic acid, polyacrylic acid, sodium gluconate, sodium chloride, fatty alcohol polyoxyethylene ether (N=9), hexamethylenetetramine, sodium benzoate, benzotriazole, and sodium fluoride in sequence into the stirring barrel;

[0033] (2) After stirring the mixture in a stirring tank for 2 minutes, sodium citrate and water were added until the liquid level reached the specified scale line and the pH value of the sampled stock solution reached 6.0;

[0034] (3) After stirring for another 8 minutes, the stock solution was diluted to volume, bottled, and packaged.

[0035] Example 2

[0036] An environmentally friendly neutral rust remover comprises 3% sodium hydroxide, 3% potassium hydroxide, 9% hydroxyethylidene diphosphonic acid, 3% tetrasodium ethylenediaminetetraacetic acid, 2% tetrasodium hydroxyethylidene diphosphate, 5% oxalic acid, 2.5% polyacrylic acid, 2.5% benzalkonium chloride, 2.4% sodium gluconate, 3.5% fatty alcohol polyoxyethylene ether (N=9), 1.6% hexamethylenetetramine, 2% dodecanedicarboxylic acid, 1.5% sodium nitrite, 1% ammonium molybdate, 8% sodium citrate, 2.5% monomethyl diethylene glycol ether, and the remainder is pure water.

[0037] The preparation method is:

[0038] (1) Pour water into a stirring barrel, and add sodium hydroxide, potassium hydroxide, hydroxyethylidene diphosphonic acid, tetrasodium ethylenediaminetetraacetic acid, tetrasodium hydroxyethylidene diphosphate, oxalic acid, polyacrylic acid, benzalkonium chloride, sodium gluconate, fatty alcohol polyoxyethylene ether (N=9), hexamethylenetetramine, dodecane dibasic acid, sodium nitrite, ammonium molybdate, and monomethyl diethylene glycol ether in sequence into the stirring barrel;

[0039] (2) After stirring the mixture in a stirring tank for 2 minutes, sodium citrate and water were added until the liquid level reached the specified scale line and the pH value of the sampled stock solution reached 6.0;

[0040] (3) After stirring for another 8 minutes, the stock solution was diluted to volume, bottled, and packaged.

[0041] Example 3

[0042] An environmentally friendly neutral rust remover, comprising 5% sodium hydroxide, 9% hydroxyethylidene diphosphonic acid, 6% tetrasodium hydroxyethylidene diphosphate, 3.2% oxalic acid, 3% polyacrylic acid, 3% benzalkonium chloride, 1.2% sodium gluconate, 1.2% sodium chloride, 3.5% polyethylene glycol, 1.5% hexamethylenetetramine, 0.5% sodium benzoate, 0.5% benzotriazole, 1% sodium nitrite, 10% sodium citrate, 3% isopropyl alcohol, and the balance being pure water;

[0043] The preparation method is:

[0044] (1) Pour water into a mixing barrel, and add sodium hydroxide, hydroxyethylidene diphosphonic acid, tetrasodium hydroxyethylidene diphosphate, oxalic acid, polyacrylic acid, benzalkonium chloride, sodium gluconate, sodium chloride, polyethylene glycol, hexamethylenetetramine, sodium benzoate, benzotriazole, sodium nitrite, and isopropyl alcohol in sequence into the mixing barrel;

[0045] (2) After stirring the mixture in a stirring tank for 2 minutes, sodium citrate and water were added until the liquid level reached the specified scale line and the pH value of the sampled stock solution reached 6.0;

[0046] (3) After stirring for another 8 minutes, the stock solution was diluted to volume, bottled, and packaged.

[0047] Example 4

[0048] An environmentally friendly neutral rust remover, comprising 6% potassium hydroxide, 12% disodium hydroxyethylidene diphosphate, 6% tetrasodium ethylenediaminetetraacetic acid, 6% isooctanoic acid, 8% polydimethyldiallylammonium chloride, 1.6% sodium gluconate, 5.4% polyethylene glycol, 1.5% hexamethylenetetramine, 2.4% dodecanedicarboxylic acid, 0.8% sodium nitrite, 8% sodium carbonate, 5% isopropyl alcohol, and the balance being pure water;

[0049] The preparation method is:

[0050] (1) Pour water into a mixing barrel, and add potassium hydroxide, disodium hydroxyethylidene diphosphate, tetrasodium ethylenediaminetetraacetic acid, isooctanoic acid, polydimethyldiallylammonium chloride, sodium gluconate, polyethylene glycol, hexamethylenetetramine, dodecane dibasic acid, sodium nitrite, and isopropyl alcohol in sequence into the mixing barrel;

[0051] (2) After stirring the mixture in a stirring tank for 2 minutes, sodium carbonate and water were added until the liquid level reached the specified scale line and the pH value of the sampled stock solution reached 6.0;

[0052] (3) After stirring for another 8 minutes, the stock solution was diluted to volume, bottled, and packaged.

[0053] Example 5

[0054] An environmentally friendly neutral rust remover is prepared from 6% sodium hydroxide, 10% hydroxyethylidene diphosphate, 6% tetrasodium ethylenediaminetetraacetic acid, 2% tetrasodium hydroxyethylidene diphosphate, 5% isooctanoic acid, 8% polyacrylic acid, 1.6% sodium gluconate, 1.6% sodium chloride, 4% fatty alcohol polyoxyethylene ether (N=9), 2% hexamethylenetetramine, 0.8% sodium benzoate, 0.8% benzotriazole, 0.8% sodium fluoride, 10% sodium citrate, 5% propylene glycol, and the balance is pure water. The preparation method is as follows:

[0055] (1) Pour water into a mixing barrel, and add sodium hydroxide, hydroxyethylidene diphosphonic acid, tetrasodium ethylenediaminetetraacetic acid, tetrasodium hydroxyethylidene diphosphonic acid, isooctanoic acid, polyacrylic acid, sodium gluconate, sodium chloride, fatty alcohol polyoxyethylene ether (N=9), hexamethylenetetramine, sodium benzoate, benzotriazole, sodium fluoride, and propylene glycol in sequence into the mixing barrel;

[0056] (2) After stirring the mixture in a stirring tank for 2 minutes, sodium citrate and water were added until the liquid level reached the specified scale line and the pH value of the sampled stock solution reached 6.0;

[0057] (3) After stirring for another 8 minutes, the stock solution was diluted to volume, bottled, and packaged.

[0058] Technical personnel should note: Although the present invention has been described according to the above specific implementation methods, the inventive concept of the present invention is not limited to this invention. Any modification using the inventive concept will be included in the scope of protection of this patent.

Claims

1. An environmentally friendly neutral rust remover, characterized in that: The composition is composed of the following raw materials in weight percentage: stripping agent 20-30%; dispersant 8-15%; composite corrosion inhibitor 3.5-6%; pH regulator 8-10%; water-based solvent 3-5%; the rest is pure water; The stripping agent is composed of a hydroxide, a hydroxyl compound mixture and an organic acid; the dispersant is composed of a sodium salt, an active agent, and one or more of polyacrylic acid, benzalkonium chloride, and polydimethylguanidine salt; the composite corrosion inhibitor is composed of hexamethylenetetramine, a main corrosion inhibitor and an inorganic salt; the pH adjuster is sodium citrate and / or sodium carbonate; The hydroxide is sodium hydroxide and / or potassium hydroxide, the hydroxy compound mixture is one or more of hydroxyethylidene diphosphonic acid, disodium hydroxyethylidene diphosphate, tetrasodium hydroxyethylidene diphosphate, and tetrasodium ethylenediaminetetraacetic acid, and the organic acid is isooctanoic acid and / or oxalic acid; The sodium salt is sodium gluconate and / or sodium chloride, and the active agent is fatty alcohol polyoxyethylene ether (N=9) and / or polyethylene glycol; The main corrosion inhibitor is one or more of sodium benzoate, benzotriazole, and dodecanedioic acid, and the inorganic salt is one or more of sodium fluoride, sodium nitrite, and ammonium molybdate.

2. The environmentally friendly neutral rust remover according to claim 1, characterized in that: The water-based solvent is composed of one or more of propylene glycol, isopropyl alcohol, and monomethyl diethylene glycol ether.

3. The environmentally friendly neutral rust remover according to claim 1, characterized in that: The hydroxide is sodium hydroxide, the hydroxy compound mixture is hydroxyethylidene diphosphonic acid and ethylenediaminetetraacetic acid tetrasodium salt, and the organic acid is isooctanoic acid.

4. The environmentally friendly neutral rust remover according to claim 1, characterized in that: The sodium salt is sodium gluconate and sodium chloride, and the active agent is fatty alcohol polyoxyethylene ether (N=9).

5. The environmentally friendly neutral rust remover according to claim 1, characterized in that: The main corrosion inhibitors are sodium benzoate and benzotriazole, and the inorganic salt is sodium fluoride.

6. The method for preparing an environmentally friendly neutral rust remover according to claim 1, characterized in that: The steps include: (1) Prepare the required weight of raw materials according to the percentage contained; (2) Pour part of the water into the mixing barrel first, and then add the stripping agent, dispersant and composite corrosion inhibitor into the mixing barrel in sequence; (3) After stirring the reaction in a stirring tank for 1-2 minutes, add pH adjuster and water until the liquid level reaches the specified scale line and the pH value of the sampled stock solution is 5.7-6.3; (4) After stirring for another 8 to 20 minutes, the original solution is adjusted to volume, bottled, and packaged.

7. The method for using the environmentally friendly neutral rust remover according to claim 1, characterized in that: It can directly wipe the surface of the workpiece to remove rust or build a bath to remove rust, and the bath removal includes the following steps: (1) Pour the stock solution into the treatment tank and dilute it with water to obtain a solution with a stock solution content of 10% to 20% and a pH value of 6.5 to 7.2; (2) Adjust the solution temperature to 20~80℃; (3) Immerse the rusted workpiece in the solution for 5 to 30 minutes and then take it out to complete the rust removal.