Alkaline rust remover and method for preparing the same

Abstract

The application provides a kind of alkaline deruster and its preparation method, belong to metal surface treatment technical field.The alkaline deruster includes: base mother liquor, alkali salt, surfactant and water;The base mother liquor includes organic acid, chloride and fluoride.The alkaline deruster provided in the application does not contain volatile inorganic acid such as phosphate acid, does not contain heavy metal or harmful substance, is friendly to environment, the alkaline deruster can simplify three processes of oil removal, water washing and rust removal into one process, greatly improves production efficiency;The alkalinity of the alkaline deruster is alkaline, and the position of weld seam, clamping seam and pipe, etc. after pickling of workpiece is prone to residual reagent, and the position will not appear re-rust phenomenon caused by strong acidic derusting, corrosion is low, and has no irritating smell.

Description

Technical Field

[0001] This invention belongs to the field of metal surface treatment technology, and particularly relates to an alkaline rust remover and its preparation method. Background Technology

[0002] Before powder coating, steel parts typically undergo machining processes such as rolling, welding, or high-temperature heat treatment, resulting in a thick oxide film and a small amount of oil on the surface. The oxide film is composed of ferrous oxide, ferric oxide, and magnetite, among others. To obtain a uniform, dense, and well-adhered powder coating on the steel surface, pretreatment is necessary to thoroughly remove the oxide film and oil.

[0003] Currently, the pretreatment step for steel in the powder coating industry is pickling, which typically uses 30%-50% high-concentration hydrochloric acid. This method can meet the pretreatment requirements for steel coating.

[0004] Due to the volatility and strong corrosiveness of hydrochloric acid, pickling operations present a harsh environment with pervasive acid fumes, posing certain safety hazards to workers. Adding acid mist inhibitors to the pickling solution can reduce hydrochloric acid volatilization, but this also introduces problems such as increased costs, reduced oxide scale removal efficiency, and decreased durability of the pickling solution. While neutral rust removal processes, currently used as an alternative to traditional rust removal, are relatively environmentally friendly, they also have drawbacks such as the risk of re-rusting if handled improperly, demanding process conditions, and rapid aging. Summary of the Invention

[0005] To solve the above problems, the present invention provides an alkaline rust remover, comprising:

[0006] Basic mother liquor, alkali salt, surfactant and water;

[0007] The base mother liquor includes organic acids, chlorides, and fluorides.

[0008] Preferably, the alkaline rust remover comprises, based on a total quantity of 1000 parts, the following components in parts by weight:

[0009] Organic acids, 0.1-400 parts;

[0010] Chloride 0.1-100 parts;

[0011] Fluoride 0.1-30 parts;

[0012] Alkali salt 0.1-100 parts;

[0013] Surfactant 0.1-100 parts;

[0014] Water is the remainder.

[0015] Preferably, the alkaline rust remover comprises, based on a total quantity of 1000 parts, the following components in parts by weight:

[0016] 150-350 parts of organic acids;

[0017] Chloride 10-100 parts;

[0018] 10-30 parts of fluoride;

[0019] 50-100 parts of alkali salt;

[0020] Surfactant 0.1-5 parts;

[0021] Water is the remainder.

[0022] Preferably, the alkaline rust remover comprises, based on a total quantity of 1000 parts, the following components in parts by weight:

[0023] Organic acids, 200-300 parts;

[0024] Chloride 50-100 parts;

[0025] 10-20 parts of fluoride;

[0026] 80-100 parts of alkali salt;

[0027] 1-2 parts surfactant;

[0028] Water is the remainder.

[0029] Preferably, the organic acid is carboxyethyl thiosuccinic acid.

[0030] Preferably, the chloride is selected from any one or more of sodium chloride, ammonium chloride, and potassium chloride;

[0031] Preferably, the chloride is sodium chloride.

[0032] Preferably, the fluoride is selected from any one or more of ammonium bifluoride, sodium fluoride, and hydrofluoric acid;

[0033] Preferably, the fluoride is ammonium hydrogen fluoride.

[0034] Preferably, the alkaline salt is any one or more of sodium hydroxide, potassium hydroxide, and soda ash;

[0035] Preferably, the alkaline salt is sodium hydroxide.

[0036] Preferably, the surfactant is any one or more of NP-10 and JFC;

[0037] Preferably, the surfactant is JFC.

[0038] Furthermore, to address the aforementioned problems, the present invention also provides a method for preparing the alkaline rust remover as described above, comprising:

[0039] Add 300-500 parts of water to a mixing container;

[0040] Organic acid, chloride and fluoride are added sequentially to the mixing container to prepare a basic mother liquor;

[0041] Add an alkaline salt to the base mother liquor and mix until dissolved;

[0042] Add a surfactant and then add water to bring the total amount to 1000 parts to obtain the alkaline rust remover.

[0043] This invention provides an alkaline rust remover and its preparation method. The alkaline rust remover comprises: a base mother liquor, an alkaline salt, a surfactant, and water; the base mother liquor includes organic acids, chlorides, and fluorides. The alkaline rust remover provided by this invention does not contain volatile inorganic acids such as phosphates and hydrochloric acid, nor does it contain heavy metals or harmful substances, making it environmentally friendly. The alkaline rust remover simplifies the three processes of degreasing, washing, and rust removal into a single process, greatly improving production efficiency. The alkaline rust remover is alkaline, preventing rust re-emergence in areas prone to residue, such as weld seams, crevices, and inside pipes, after pickling, unlike the rust re-emergence phenomenon caused by strong acid rust removal. It has low corrosiveness and no irritating odor. Detailed Implementation

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] This invention provides an alkaline rust remover, comprising:

[0046] Basic mother liquor, alkali salt, surfactant and water;

[0047] The base mother liquor includes organic acids, chlorides, and fluorides.

[0048] The organic acids mentioned above refer to acidic organic compounds. Common organic acids can be carboxylic acids or substances containing carboxylic acids (R-COOH). The organic acids added in this invention chelate rust, thereby removing surface rust.

[0049] The above-mentioned chlorides refer to compounds containing chloride ions (Cl). -Chloride compounds are formed by the reaction of chlorine with other elements; they can be inorganic or organic. The addition of chloride to alkaline rust removers enhances the chelating properties of organic acids, thus accelerating rust removal.

[0050] The above-mentioned fluorides are those containing fluoride ions (F). - These compounds are inorganic or organic, typically formed by the combination of fluorine with other elements such as metals or carbon. In this invention, the addition of fluorides enhances the corrosion resistance of the substrate and accelerates rust removal.

[0051] As mentioned above, the role of alkali salts is to neutralize the acidity of organic acids and adjust the system to alkaline.

[0052] By adding alkaline salts, the overall pH environment of the alkaline rust remover can be maintained within the alkaline range, thereby avoiding excessive corrosion of steel parts during the surface treatment process.

[0053] As mentioned above, the purpose of adding surfactants is to wet the surface.

[0054] The alkaline rust remover provided by this invention does not contain volatile inorganic acids such as phosphate and hydrochloric acid, nor does it contain heavy metals or harmful substances. It is environmentally friendly and can simplify the three processes of degreasing, washing, and rust removal into a single process, greatly improving production efficiency. The alkaline rust remover is alkaline, so the weld seams, crevices, and pipes where the agent is likely to remain after pickling will not experience the rust re-rusting phenomenon caused by strong acid rust removal. It has low corrosiveness and no irritating odor.

[0055] Furthermore, the alkaline rust remover, calculated in parts per 1000 parts, comprises the following components by weight:

[0056] Organic acids, 0.1-400 parts;

[0057] Chloride 0.1-100 parts;

[0058] Fluoride 0.1-30 parts;

[0059] Alkali salt 0.1-100 parts;

[0060] Surfactant 0.1-100 parts;

[0061] Water is the remainder.

[0062] In order to ensure that the final alkaline rust remover has a suitable pH and is alkaline, the amount of alkaline salt added can be flexibly and appropriately adjusted to ensure that the acid-base environment of the alkaline rust remover is suitable and meets the pH requirements of this invention.

[0063] Furthermore, the alkaline rust remover, calculated in parts per 1000 parts, comprises the following components by weight:

[0064] 150-350 parts of organic acids;

[0065] Chloride 10-100 parts;

[0066] 10-30 parts of fluoride;

[0067] 50-100 parts of alkali salt;

[0068] Surfactant 0.1-5 parts;

[0069] Water is the remainder.

[0070] Furthermore, the alkaline rust remover, calculated in parts per 1000 parts, comprises the following components by weight:

[0071] Organic acids, 200-300 parts;

[0072] Chloride 50-100 parts;

[0073] 10-20 parts of fluoride;

[0074] 80-100 parts of alkali salt;

[0075] 1-2 parts surfactant;

[0076] Water is the remainder.

[0077] Furthermore, the organic acid is carboxyethyl thiosuccinic acid.

[0078] The most common organic acids mentioned above are carboxylic acids, which contain a carboxyl group (R-COOH). Their function is to chelate rust, thereby removing surface rust.

[0079] Furthermore, the chloride is selected from any one or more of sodium chloride, ammonium chloride, and potassium chloride;

[0080] In a preferred embodiment, the chloride is sodium chloride.

[0081] Furthermore, the fluoride is selected from any one or more of ammonium bifluoride, sodium fluoride, and hydrofluoric acid;

[0082] In a preferred embodiment, the fluoride is ammonium hydrogen fluoride.

[0083] Furthermore, the alkaline salt is any one or more of sodium hydroxide, potassium hydroxide, and soda ash.

[0084] In a preferred embodiment, the alkaline salt is sodium hydroxide.

[0085] Furthermore, the surfactant is any one or more of NP-10 and JFC;

[0086] In a preferred embodiment, the surfactant is JFC.

[0087] As mentioned above, NP-10 and JFC are both types of surfactants, with different chemical structures and uses.

[0088] (1) NP-10: This is a nonionic surfactant, referring to nonylphenol polyoxyethylene ether containing 10 repeating ethoxy (-OCH2CH2-) units. It is widely used in detergents, washing agents and industrial applications.

[0089] (2) JFC: JFC, also known as penetrating agent, is a nonionic surfactant with excellent penetration properties. It is mainly used in oilfield development, groundwater remediation, and wastewater treatment. The chemical formula of JFC is RO(CH2CH2O). n H is a light-colored liquid with a neutral pH. It is stable, non-toxic, non-flammable, and resistant to strong acids, strong alkalis, sodium hypochlorite, hard water, and heavy metal salts. In metal surface treatment, JFC can be used to increase the permeability of polymer materials and reduce surface tension, and is commonly used in processes such as metal surface degreasing.

[0090] These surfactants share the common characteristic of containing polyoxyethylene chains, which enables them to reduce the surface tension of water, thereby enhancing their cleaning and emulsifying properties. The specific application of each surfactant depends on its chemical structure and properties.

[0091] Furthermore, the present invention also provides a method for preparing the alkaline rust remover as described above, comprising:

[0092] Step S1: Add 300-500 parts of water to the mixing container;

[0093] Step S2: Organic acid, chloride and fluoride are added sequentially to the mixing container to prepare a basic mother liquor;

[0094] Step S3: Add alkaline salt to the basic mother liquor and mix until dissolved;

[0095] Step S4: Add surfactant and replenish the total amount with water to 1000 parts to obtain the alkaline rust remover.

[0096] The reasons for adding raw materials in batches rather than mixing them all at once when preparing alkaline rust removers are as follows:

[0097] (1) Controlling the reaction: Some components may react under specific conditions. Stepwise addition can control these reactions and ensure that each reaction can proceed under suitable conditions.

[0098] (2) Ensure uniform mixing: Step-by-step addition ensures that each ingredient is fully mixed before the next ingredient is added, thus making the final product uniform in composition.

[0099] (3) Preventing sedimentation or clumping: Some ingredients may form sediment or clumps when mixed directly. Adding in batches helps avoid this and ensures the quality of the rust remover.

[0100] (4) pH and solubility control: Different components have different effects on the pH and solubility of the solution. Gradual addition can control these parameters and ensure that all components are added under suitable pH and solubility conditions.

[0101] In summary, adding raw materials in stages is to ensure the controllability of the reaction, the homogeneity and stability of the product, and the efficacy and safety of the final product.

[0102] The present invention will be further illustrated below with specific embodiments. However, it should be understood that these embodiments are merely for the purpose of more detailed illustration and should not be construed as limiting the present invention in any way.

[0103] Example 1:

[0104] In this embodiment, an alkaline rust remover was prepared. The specific parameters and dosages are shown in Table 1.

[0105] Experimental methods:

[0106] (1) Weight parts of each component:

[0107] Organic acid: 200 parts of carboxyethyl thiosuccinic acid;

[0108] Chloride: 50 parts sodium chloride;

[0109] Fluoride: 10 parts ammonium bifluoride;

[0110] Alkali salt: 80 parts sodium hydroxide;

[0111] Surfactant: 1 part JFC.

[0112] (2) Preparation method: Take 300 parts of water and add them to a mixing container; add organic acid and chloride to the mixing container in sequence, stir for half an hour until completely dissolved, slowly add fluoride, stir for half an hour and then prepare the basic mother liquor;

[0113] Add alkaline salt to the basic mother liquor and stir until dissolved;

[0114] After adding the surfactant, the total amount is increased to 1000 parts by adding water to obtain the alkaline rust remover.

[0115] Example 2:

[0116] In this embodiment, an alkaline rust remover was prepared.

[0117] Experimental methods:

[0118] (1) Weight parts of each component:

[0119] Organic acid: 260 parts of carboxyethyl thiosuccinic acid;

[0120] Chloride: 70 parts sodium chloride;

[0121] Fluoride: 15 parts ammonium bifluoride;

[0122] Alkali salt: 90 parts sodium hydroxide;

[0123] Surfactant: 1 part JFC.

[0124] (2) The preparation method is the same as in Example 1.

[0125] Example 3:

[0126] In this embodiment, an alkaline rust remover was prepared. The specific parameters and dosages are shown in Table 1.

[0127] Experimental methods:

[0128] (1) Weight parts of each component:

[0129] Organic acid: 300 parts of carboxyethyl thiosuccinic acid;

[0130] Chloride: 100 parts sodium chloride;

[0131] Fluoride: 20 parts ammonium bifluoride;

[0132] Alkali salt: 100 parts sodium hydroxide;

[0133] Surfactant: 2 parts JFC.

[0134] (2) The preparation method is the same as in Example 1.

[0135] Comparative Example 1:

[0136] In this embodiment, an alkaline rust remover was prepared. The specific parameters and dosages are shown in Table 1.

[0137] Experimental methods:

[0138] (1) Weight parts of each component:

[0139] Organic acid: 270 parts of carboxyethyl thiosuccinic acid;

[0140] Chloride: 60 parts sodium chloride;

[0141] Alkali salt: 90 parts sodium hydroxide;

[0142] Surfactant: 1 part JFC.

[0143] (2) The preparation method is the same as in Example 1 (ignoring the missing components in the preparation method steps based on this example).

[0144] Comparative Example 2:

[0145] In this embodiment, an alkaline rust remover was prepared. The specific parameters and dosages are shown in Table 1.

[0146] Experimental methods:

[0147] (1) Weight parts of each component:

[0148] Organic acid: 150 parts of carboxyethyl thiosuccinic acid;

[0149] Chloride: 50 parts sodium chloride;

[0150] Fluoride: 15 parts ammonium bifluoride;

[0151] Alkali salt: 90 parts sodium hydroxide;

[0152] Surfactant: 1 part JFC.

[0153] (2) The preparation method is the same as in Example 1.

[0154] Comparative Example 3:

[0155] In this embodiment, an alkaline rust remover was prepared. The specific parameters and dosages are shown in Table 1.

[0156] Experimental methods:

[0157] (1) Weight parts of each component:

[0158] Organic acid: 285 parts of carboxyethyl thiosuccinic acid;

[0159] Chloride: 20 parts sodium chloride;

[0160] Fluoride: 10 parts ammonium bifluoride;

[0161] Alkali salt: 90 parts sodium hydroxide;

[0162] Surfactant: 1.5 parts JFC.

[0163] (2) The preparation method is the same as in Example 1.

[0164] Comparative Example 4:

[0165] In this example, an alkaline rust remover was prepared, and the specific parameters and dosages are shown in Table 1 for reference.

[0166] Experimental method:

[0167] (1) Parts by weight of each component charged:

[0168] Organic acid: 285 parts of carboxyethylthiosuccinic acid;

[0169] Chloride: 80 parts of sodium chloride;

[0170] Fluoride: 10 parts of ammonium bifluoride;

[0171] Alkali salt: 40 parts of sodium hydroxide;

[0172] Surfactant: 2 parts of JFC.

[0173] (2) The preparation method is the same as that of Example 1.

[0174] Comparative Example 5:

[0175] In this example, an alkaline rust remover was prepared, and the specific parameters and dosages are shown in Table 1 for reference.

[0176] Experimental method:

[0177] (1) Parts by weight of each component charged:

[0178] Organic acid: 290 parts of citric acid;

[0179] Chloride: 50 parts of sodium chloride;

[0180] Fluoride: 12 parts of ammonium bifluoride;

[0181] Alkali salt: 80 parts of sodium hydroxide;

[0182] Surfactant: 1 part of JFC.

[0183] (2) The preparation method is the same as that of Example 1 (using citric acid as the organic acid in this example).

[0184] Table 1. Comparison table of each component and dosage in the examples

[0185]

[0186] Note: In Table 1 and Table 2, "Shi" is the abbreviation of "Example", and the corresponding "Shi 1" is "Example 1"; similarly, "Dui" is the abbreviation of "Comparative Example", and "Dui 1" is "Comparative Example 1".

[0187] Horizontal comparative experiment:

[0188] Rust removal and rust re-reversion effect test:

[0189] Rusting time: This refers to the time it takes for the surface of a workpiece to corrode and rust again after it has been left to air naturally for a period of time following rust removal.

[0190] Rust removal time: This is the time required to clean the oxidized and rusted parts of the workpiece surface.

[0191] Table 2. Comparison of degreasing and rust removal effects between the examples and comparative examples.

[0192] Performance testing Real 1 Real 2 Real 3 For 1 2 3 4 5 Rusting time s 122 123 124 118 122 125 20 120 Rust removal time (min) 18 16 15 27 45 25 15 60

[0193] The test results in Table 2 show that, compared with Examples 1-3 which use the technology of this invention, the rust removal performance of the comparative examples decreased when the type of organic acid was changed (Comparative Example 5) or its content was outside the process range (Comparative Examples 3-4); the removal of fluoride (Comparative Example 1) and the reduction of chloride (Comparative Example 3) also reduced the rust removal performance; the reduction of alkaline salts further accelerated the re-rusting of the workpiece.

[0194] Workpieces treated with carefully selected alkaline rust removers can not only remove rust but also slow down the recurrence of rust, which is something that traditional and neutral rust removal processes cannot achieve. At the same time, it is environmentally friendly and harmless to the human body.

[0195] In summary, the alkaline rust remover provided by this invention does not contain volatile inorganic acids such as phosphate and hydrochloric acid, nor does it contain heavy metals or harmful substances. It is environmentally friendly and can simplify the three processes of degreasing, washing, and rust removal into a single process, greatly improving production efficiency. The alkaline rust remover has a neutral pH, and the weld seams, crevices, and pipes where the agent is easily retained after pickling will not experience the rust return phenomenon caused by strong acid rust removal. It has low corrosiveness and no irritating odor.

[0196] The above describes preferred embodiments and corresponding examples of the present invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, including but not limited to adjustments in proportion, process, dosage and reaction vessel, all of which fall within the protection scope of the present invention.

Claims

1. An alkaline rust remover, characterized in that, The alkaline rust remover, calculated in parts per 1000 parts, comprises the following components by weight: Organic acids, 200-300 parts; Chloride 50-100 parts; 10-20 parts of fluoride; 80-100 parts alkali; 1-2 parts surfactant; Water is the remainder; The organic acid is carboxyethyl thiosuccinic acid; The chloride is selected from any one or more of sodium chloride, ammonium chloride, and potassium chloride; The fluoride is selected from any one or more of ammonium bifluoride, sodium fluoride and hydrofluoric acid; The alkali is sodium hydroxide and / or potassium hydroxide.

2. The alkaline rust remover as described in claim 1, characterized in that, The chloride is sodium chloride.

3. The alkaline rust remover as described in claim 1, characterized in that, The fluoride is ammonium hydrogen fluoride.

4. The alkaline rust remover as described in claim 1, characterized in that, The alkali is sodium hydroxide.

5. The alkaline rust remover as described in claim 1, characterized in that, The surfactant is any one or more of NP-10 and JFC.

6. The alkaline rust remover as described in claim 5, characterized in that, The surfactant is JFC.

7. A method for preparing the alkaline rust remover as described in any one of claims 1-6, characterized in that, include: Add 300-500 parts of water to a mixing container; Organic acid, chloride and fluoride are added sequentially to the mixing container to prepare a basic mother liquor; Add alkaline salt to the base mother liquor and mix until dissolved; Add a surfactant and then add water to bring the total amount to 1000 parts to obtain the alkaline rust remover.

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