Low-foam non-phosphorus compound degreasing agent and preparation method thereof

Abstract

The invention relates to a low-foam non-phosphorus compound degreasing agent and a preparation method, and belongs to the technical field of strip steel surface cleaning. The degreasing agent comprises the following components in percentage by mass: 2%-5% of sodium carbonate, 7%-12% of sodium hydroxide, 1.5%-10% of a non-phosphorus builder, 4%-7% of ethylene diamine tetra-acid disodium salt, 4%-7% of sodium carboxymethyl cellulose, 1.5%-3% of 4A zeolite, 12%-20% of a compound surfactant, 0.2%-1.5% of a solubilizer, 1%-4% of polyacrylamide and 0.2%-3.5% of a polyether modified silicon defoaming agent. The components perform their own functions and jointly form an efficient cleaning system of the degreasing agent.

Description

Technical Field

[0001] The present application relates to the technical field of strip surface cleaning, and particularly to a low-foam phosphorus-free compound degreaser and a preparation method thereof. Background Art

[0002] During the cold rolling process of strip steel, under the action of a great frictional force between the rolling mill rolls and the strip steel, a large amount of iron powder is generated on the surfaces of the rolling mill rolls and the strip steel. Part of the iron powder will adhere to the surface of the strip steel. At the same time, a large amount of heat is generated in the deformation zone of the strip steel, causing the cold rolling fluid to demulsify due to heat, and forming an oil film on the surfaces of the rolling mill rolls and the strip steel, thus playing a lubricating role. However, part of the oil will adhere to the surface of the strip steel, and together with dust and sweat, it forms a firm dirt on the high-temperature surface of the strip steel. In addition, the surface of the strip steel will also carry some anti-rust oil, dust and other dirt during storage and transportation. After cold rolling, there are an oil film layer, a dirt layer and an oxide film layer on the surface, among which the dirt layer is the most difficult to wash, mostly formed by oil soaps formed by metal powders such as iron powder and palm oil and heavy polymers of rolling oil formed by the cracking of rolling oil. These dirt are very harmful to subsequent processing such as annealing and coating, so generally a degreasing line is added after cold rolling or before surface treatment such as electroplating and painting.

[0003] Traditional degreasers require a relatively high cleaning temperature, and have poor anti-corrosion and rust-proof performance, and poor degreasing effect, etc. With the development of modern degreasing technology and the improvement of modern processes, the requirements for degreasers at home and abroad are developing towards the aspects of high efficiency, low energy consumption, pollution-free, simple process, and no health hazards to the human body. At present, degreasers generally use phosphorus-containing water-based cleaning agents. Although the cleaning effect has been improved, there will be residual phosphorus in the discharged waste liquid, which is likely to cause eutrophication of water bodies, affect the ecological environment, and even have a bad impact on the environment. And the treatment cost of phosphorus-containing wastewater is relatively high. Therefore, exploring high-efficiency and environmentally friendly phosphorus-free degreasers has become one of the hot research topics today. Summary of the Invention

[0004] The present application provides a low-foam phosphorus-free compound degreaser and a preparation method thereof to solve the following technical problems: how to solve the environmental pollution problems existing in the industrial cleaning process of phosphorus-containing water-based cleaning agents.

[0005] In a first aspect, an embodiment of the present application provides a low-foam phosphorus-free compound degreaser. By mass fraction, the degreaser includes: sodium carbonate: 2% - 5%, sodium hydroxide: 7% - 12%, phosphorus-free co-cleaning agent: 1.5% - 10%, disodium ethylenediaminetetraacetate: 4% - 7%, sodium carboxymethylcellulose: 4% - 7%, 4A zeolite: 1.5% - 3%, compound surfactant: 12% - 20%, solubilizer: 0.2% - 1.5%, polyacrylamide: 1% - 4%, polyether-modified silicone defoaming agent: 0.2% - 3.5%.

[0006] Optionally, the phosphorus-free builder is at least one of sodium metasilicate nonahydrate, sodium citrate, and sodium gluconate.

[0007] Optionally, the compound surfactant is obtained by compounding sodium lignosulfonate and fatty alcohol polyoxyethylene polyoxypropylene ether.

[0008] Optionally, the mass ratio of the sodium lignosulfonate to the fatty alcohol polyoxyethylene polyoxypropylene ether is (0.8-1.5):1.

[0009] Optionally, the solubilizer is at least one of sorbitan fatty acid ester and octyliminodipropionate.

[0010] In a second aspect, an embodiment of the present application provides a method for preparing the degreaser described in the first aspect, the method comprising:

[0011] According to the mass fraction, mixing and stirring the phosphorus-free builder, the disodium ethylenediaminetetraacetate, the sodium carboxymethylcellulose, and the 4A zeolite in water to obtain a first mixture;

[0012] According to the mass fraction, mixing and stirring the first mixture, the compound surfactant, the solubilizer, the polyacrylamide, and the defoamer to obtain a second mixture;

[0013] According to the mass fraction, mixing and stirring the second mixture, the sodium hydroxide, and the sodium carbonate in water to obtain a third mixture;

[0014] After the temperature of the third mixture reaches room temperature, perform a fourth mixing and stirring to obtain a degreaser.

[0015] Optionally, the time of the first mixing and stirring is 20 min to 40 min, and the rotation speed of the first mixing and stirring is 200 r / min to 550 r / min.

[0016] Optionally, the temperature of the second mixing and stirring is 50 °C to 60 °C, the time of the second mixing and stirring is 15 min to 40 min, and the rotation speed of the second mixing and stirring is 200 r / min to 500 r / min.

[0017] Optionally, the temperature of the third mixing and stirring is 50 °C to 70 °C, the time of the third mixing and stirring is 30 min to 60 min, and the rotation speed of the third mixing and stirring is 150 r / min to 400 r / min.

[0018] Optionally, the time of the fourth mixing and stirring is 20 min to 40 min, and the rotation speed of the fourth mixing and stirring is 150 r / min to 400 r / min.

[0019] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0020] The present application provides a low-foaming and phosphorus-free compound degreaser. By mass fraction, the degreaser includes: sodium carbonate: 2% - 5%, sodium hydroxide: 7% - 12%, phosphorus-free builder: 1.5% - 10%, disodium ethylenediaminetetraacetate: 4% - 7%, sodium carboxymethylcellulose: 4% - 7%, 4A zeolite: 1.5% - 3%, compound surfactant: 12% - 20%, solubilizer: 0.2% - 1.5%, polyacrylamide: 1% - 4%, polyether-modified silicone defoamer: 0.2% - 3.5%. The use of an environmentally friendly phosphorus-free builder to replace traditional phosphorus-containing additives effectively reduces the phosphorus content in water bodies, thus effectively inhibiting the problem of water eutrophication. The compound surfactant has excellent surfactant properties, can quickly penetrate stains and break down grease, achieving a high-efficiency and thorough cleaning effect. In addition, the low-foaming and phosphorus-free compound degreaser also adds a variety of special components such as 4A zeolite with a three-dimensional framework structure, solubilizer, defoamer, and corrosion inhibitor polyacrylamide. These components not only enhance the cleaning ability of the degreaser but also further reduce the negative impact on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic flow chart of a preparation method of a low-foaming and phosphorus-free compound degreaser provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0025] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range; in addition, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0026] In this document, terms including "comprising" etc. mean "including but not limited to". Relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "And / or", which describes the associated relationship of associated objects, indicates that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone; where A and B can be singular or plural. "At least one" means one or more, and "a plurality" means two or more; "at least one kind", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single item (piece) or plural items (pieces); for example, "at least one of a, b, or c", or, "at least one of a, b, and c" can both mean: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively. "Part representation methods" such as weight parts, mass parts, etc. represent the proportional relationship between each component. In the proportional relationships involved in this document, the parameters that need to be described by the ratio should be understood as the antecedents of the ratio formula in the order of description, and the ratio numbers should be understood as the consequents of the ratio formula. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one by one with the ratio numbers in the ratio formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0027] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in this document can be obtained through market purchase or can be prepared by existing methods.

[0028] In a first aspect, an embodiment of the present application provides a low-foaming and phosphorus-free compound degreaser. By mass fraction, the degreaser includes: sodium carbonate: 2% - 5%, sodium hydroxide: 7% - 12%, phosphorus-free builder: 1.5% - 10%, disodium ethylenediaminetetraacetate: 4% - 7%, sodium carboxymethyl cellulose: 4% - 7%, 4A zeolite: 1.5% - 3%, compound surfactant: 12% - 20%, solubilizer: 0.2% - 1.5%, polyacrylamide: 1% - 4%, polyether-modified silicone defoamer: 0.2% - 3.5%.

[0029] The low-foaming and phosphorus-free compound degreaser provided by the embodiment of the present application is a new type of environmentally friendly cleaning agent, and its unique formula design aims to achieve the perfect combination of efficient degreasing and environmental protection concept.

[0030] The phosphorus-free builder decomposes oil molecules into small molecules, making them easier to be rinsed away by water, thereby effectively removing oil and dirt on the surfaces of various substrates. At the same time, the phosphorus-free builder avoids environmental problems that may be caused by traditional phosphorus-based builders, such as eutrophication, etc., which is beneficial to protecting the ecological environment. Exemplarily, the mass fraction of the phosphorus-free builder can be 1.5%, 3.5%, 6.5%, 9.5%, 10%, etc.

[0031] Sodium hydroxide has a strong saponification reaction and is the main component of alkaline cleaning agents. Exemplarily, the mass fraction of sodium hydroxide can be 7%, 8%, 9%, 10%, 11%, 12%, etc.

[0032] Sodium carbonate can react with acidic substances to generate salts and water, thereby reducing the acidity and alkalinity of the cleaning solution and maintaining the acid-base balance of the cleaning solution. The maintenance of this acid-base balance helps to prevent the corrosion of metal surfaces by acidic substances, and also helps to improve the stability and washing effect of the cleaning solution. Exemplarily, the mass fraction of sodium carbonate can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0033] The organic metal chelating agents disodium ethylenediaminetetraacetate (EDTA) and sodium carboxymethyl cellulose (CMC) both have strong chelating effects on metal ions in oil stains. The washing effect of EDTA is not inferior to that of the traditional metal chelating agent sodium tripolyphosphate (STPP), while the chelating ability of CMC is even 5 - 7 times that of STPP, and it also has a certain oil solubility. Exemplarily, the mass fraction of disodium ethylenediaminetetraacetate can be 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, etc.; the mass fraction of sodium carboxymethyl cellulose can be 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, etc.

[0034] The compound surfactant plays a crucial role in the degreasing process. Surfactants have the ability to reduce surface tension, which enables them to more effectively contact and penetrate the surfaces of workpieces with various complex geometries, deeply removing grease and stains that are difficult to reach. Through carefully selected compounding schemes, these surfactants can also act synergistically to enhance each other's cleaning efficacy, while suppressing foam generation, maintaining a low-foam and stable cleaning process, and facilitating operation and management. Exemplarily, the mass fraction of the compound surfactant can be 12% - 20% etc.

[0035] 4A zeolite with a three-dimensional framework structure belongs to inorganic chelating agents. Acting together with organic chelating agents, it further emulsifies and adsorbs oil stains. Moreover, 4A zeolite has a synergistic effect with surfactants, which is beneficial to improving the degreasing effect. Exemplarily, the mass fraction of 4A zeolite can be 1.5%, 1.8%, 2.1%, 2.4%, 2.7%, 3% etc.

[0036] The role of solubilizers in degreasing agents is to convert water-insoluble substances such as grease and dirt into water-soluble forms. In this way, during the cleaning process, solubilizers can effectively disperse grease in water, forming a homogeneous and stable solution, avoiding secondary pollution, and simplifying the subsequent wastewater treatment process. Exemplarily, the mass fraction of solubilizers can be 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.5% etc.

[0037] Adding polyether-modified silicone defoamers can reduce the negative impact of foaming. Exemplarily, the mass fraction of polyether-modified silicone defoamers can be 0.2%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5% etc.

[0038] The corrosion inhibitor polyacrylamide is a high-molecular compound, and its role in degreasing agents is mainly reflected in the protection of metal surfaces. Polyacrylamide can undergo chemical reactions or physical adsorption with metal surfaces to form a dense and stable protective film. This protective film can effectively isolate corrosive media such as oxygen, moisture, and other chemical substances from direct contact with the metal; at the same time, it also prevents surface damage caused by mechanical friction. In this way, the corrosion rate of the metal due to chemical reactions or physical wear is significantly reduced, and the service life of the equipment is extended; in addition, due to the good film-forming performance and stability of polyacrylamide, it can also form a lubricating film on the surface of the equipment to reduce frictional losses and lower the noise level during equipment operation. Exemplarily, the mass fraction of polyacrylamide can be 1%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4% etc.

[0039] To achieve the balance between the best cleaning effect and environmental protection performance, the proportions of these components have undergone strict scientific experiments and optimized adjustments. In this way, the low-foam and phosphorus-free compound degreaser not only ensures efficient degreasing effect, but also minimizes the negative impact on the environment, meeting the requirements of green and high-efficiency in today's industrial cleaning field.

[0040] In some embodiments, the phosphorus-free builder is at least one of sodium metasilicate nonahydrate, sodium citrate, and sodium gluconate.

[0041] Citrates can undergo chelation reactions with hard water ions to form soluble complexes, thus effectively removing hard water ions on the metal surface and preventing the formation of scale. This not only helps to keep the metal surface clean and shiny, but also effectively prevents the blockage and corrosion of equipment by scale, improving the operating efficiency and lifespan of the equipment. Sodium metasilicate nonahydrate can enhance the dissolution, suspension, and stable dispersion of oil stains. Sodium gluconate has few bubbles but excellent cleaning effect, is pollution-free and harmless, and does not cause pests.

[0042] In some embodiments, the compound surfactant is obtained by compounding sodium lignin sulfonate and fatty alcohol polyoxyethylene polyoxypropylene ether.

[0043] In some embodiments, the mass ratio of the sodium lignin sulfonate to the fatty alcohol polyoxyethylene polyoxypropylene ether is (0.8 - 1.5):1.

[0044] In the specific formulation design of the compound surfactant, the mass ratio of sodium lignin sulfonate to fatty alcohol polyoxyethylene polyoxypropylene ether has been precisely calculated and optimized. Sodium Lignin Sulfonate is a natural polymer compound derived from the xylem of plants. After modification and sulfonation treatment, it has good dispersibility and wettability. It can reduce the surface tension of the liquid, improve the spreading ability and penetration speed of the cleaning solution; while fatty alcohol polyoxyethylene polyoxypropylene ether (such as Ceteareth-25, a non-ionic surfactant containing both polyoxyethylene and polyoxypropylene chain segments) has excellent low-foam characteristics.

[0045] By adjusting the ratio of the two, the degreaser can achieve the goal of low-foam environmental protection while maintaining high cleaning ability. On the one hand, sodium lignin sulfonate can promote the emulsification and dispersion of oils and prevent the redeposition of dirt; on the other hand, fatty alcohol polyoxyethylene polyoxypropylene ether can effectively reduce the foam generated during the cleaning process, preventing excessive foam from affecting the operation vision and wasting resources. The two work together, not only improving the cleaning efficiency of the degreaser, but also reducing the environmental burden.

[0046] In some embodiments, the solubilizer is at least one of sorbitan fatty acid ester and octyliminodipropionate.

[0047] As a solubilizer, sorbitan fatty acid ester can effectively convert water-insoluble substances such as oils and dirt into water-soluble forms, so as to effectively disperse oils in water during the cleaning process, form a homogeneous and stable solution, avoid secondary pollution, and simplify the subsequent wastewater treatment process.

[0048] Octyliminodipropionate is a compound with a special structure and is usually used as a surfactant or solubilizer. It has good solubility and dispersibility and can form a stable micelle structure in water, thus effectively solubilizing oils and dirt. In the degreaser, octyliminodipropionate as a solubilizer can significantly improve the cleaning efficiency of the degreaser. It can interact with oil molecules, wrap them inside the micelles, and carry them away from the substrate surface through the action of water flow, thus achieving an efficient degreasing effect.

[0049] Figure 1 It is a schematic flow chart of a preparation method of a low-foam phosphorus-free compound degreaser provided by an embodiment of the present application.

[0050] Please refer to Figure 1 , Second, an embodiment of the present application provides a preparation method of the degreaser described in the first aspect, and the method includes:

[0051] S1. According to the mass fraction, mix and stir the phosphorus-free builder, disodium ethylenediaminetetraacetate, sodium carboxymethylcellulose and 4A zeolite in water for the first time to obtain a first mixture;

[0052] In the first mixing and stirring stage, we first accurately weigh the phosphorus-free builder, disodium ethylenediaminetetraacetate, sodium carboxymethylcellulose, 4A zeolite and part of the water, and put them into the reaction kettle. Set appropriate stirring speed and time, start the stirring device, and make each raw material fully dissolve and mix in water.

[0053] In some embodiments, the time of the first mixing and stirring is 20 min to 40 min, and the rotation speed of the first mixing and stirring is 200 r / min to 550 r / min.

[0054] The first mixing and stirring can ensure the full dissolution of raw materials to form a uniform solution without precipitation. Exemplarily, the time of the first mixing and stirring can be 20 min, 24 min, 28 min, 32 min, 36 min, 40 min, etc.; the rotation speed of the first mixing and stirring can be 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min, 550 r / min, etc.

[0055] S2. According to the mass fraction, perform the second mixing and stirring on the first mixture, the compound surfactant, the solubilizer, the polyacrylamide and the defoamer to obtain a second mixture;

[0056] Then enter the second mixing and stirring stage. At this time, add the compound surfactant, the solubilizer, the polyacrylamide and the defoamer into the reaction kettle according to a predetermined ratio, and set appropriate rotation speed and temperature for stirring.

[0057] In some embodiments, the temperature of the second mixing and stirring is 50°C to 60°C, the time of the second mixing and stirring is 15 min to 40 min, and the rotation speed of the second mixing and stirring is 200 r / min to 500 r / min.

[0058] The surfactant has the function of reducing the surface tension in the solution, which helps to improve the cleaning efficiency of the degreaser. By precisely controlling the stirring parameters, it is ensured that the surfactant can be fully dissolved and uniformly mixed with the solution to form a stable emulsion structure. Exemplarily, the temperature of the second mixing and stirring can be 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, etc.; the time of the second mixing and stirring can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, etc.; the rotation speed of the second mixing and stirring can be 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min, etc.

[0059] S3. According to the mass fraction, perform the third mixing and stirring on the second mixture, the sodium hydroxide and the sodium carbonate in water to obtain a third mixture;

[0060] In the third mixing and stirring stage, slowly add the remaining water into the reaction kettle, and at the same time reduce the stirring speed to avoid uneven distribution of the degreaser components due to violent stirring. Through low-speed stirring, fully mix the remaining water with the previously mixed solution until the required degreaser concentration and viscosity are reached.

[0061] In some embodiments, the temperature of the third mixing and stirring is 50°C to 70°C, the time of the third mixing and stirring is 30 min to 60 min, and the rotation speed of the third mixing and stirring is 150 r / min to 400 r / min.

[0062] The third mixing and stirring aims to finely adjust the physical properties of the degreaser to meet the requirements of industrial applications or household use. Exemplarily, the temperature of the third mixing and stirring can be 50°C, 54°C, 58°C, 62°C, 66°C, 70°C, etc.; the time of the third mixing and stirring can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc.; the rotation speed of the third mixing and stirring can be 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, etc.

[0063] S4. After the temperature of the third mixture reaches room temperature, perform the fourth mixing and stirring to obtain the degreaser.

[0064] Finally, after the liquid in the kettle is naturally cooled and the temperature reaches room temperature, continue the fourth mixing and stirring. In the embodiments of the present application, the room temperature is 15°C to 30°C.

[0065] In some embodiments, the time of the fourth mixing and stirring is 20 min to 40 min, and the rotation speed of the fourth mixing and stirring is 150 r / min to 400 r / min.

[0066] Exemplarily, the time of the fourth mixing and stirring can be 20 min, 24 min, 28 min, 32 min, 36 min, 40 min, etc.; the rotation speed of the fourth mixing and stirring can be 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, etc.

[0067] In summary, the low-foam phosphorus-free compound degreaser provided by the embodiments of the present application realizes the perfect combination of high-efficiency degreasing and environmental protection concept through a carefully designed formula and preparation process. This degreaser not only has excellent degreasing effect, but also reduces the negative impact on the environment, meeting the green and high-efficiency industrial cleaning requirements.

[0068] The preparation product of the preparation method of this degreaser is the above degreaser. Since the preparation method of this degreaser adopts some or all of the technical solutions of the degreaser embodiments, it has at least all the beneficial effects brought by the technical solutions of the degreaser embodiments, which will not be elaborated here one by one.

[0069] The present application will be further elaborated below in conjunction with specific embodiments. For the experimental methods without specific conditions indicated in the following embodiments, they are generally determined according to national standards / industry standards; if there are no corresponding national standards / industry standards, they are carried out according to general international standards, conventional conditions or the conditions recommended by the manufacturer.

[0070] The components of Examples 1-4 and Comparative Examples 1-2 are shown in Table 1.

[0071] Table 1 Components of Examples 1-4 and Comparative Examples 1-2 (wt%)

[0072]

[0073] Based on the components of the examples and comparative examples, this example also provides a preparation method of a low-foaming phosphorus-free compound degreaser, including the following steps:

[0074] According to the mass fractions, the phosphorus-free builder, disodium ethylenediaminetetraacetate, sodium carboxymethylcellulose and 4A zeolite are first mixed and stirred in water to obtain a first mixture.

[0075] According to the mass fractions, the first mixture, the compound surfactant, the solubilizer, polyacrylamide and the defoamer are secondarily mixed and stirred to obtain a second mixture.

[0076] According to the mass fractions, the second mixture, sodium hydroxide and sodium carbonate are tertiarily mixed and stirred in water to obtain a third mixture.

[0077] After the temperature of the third mixture reaches room temperature, a fourth mixing and stirring is carried out to obtain the degreaser. For the specific process parameters of the preparation, please refer to Table 2.

[0078] Table 2

[0079]

[0080] (1) Degreasing performance detection:

[0081] (1) Material pretreatment

[0082] The test material is a common carbon steel sheet with dimensions of 100.0 mm × 50.0 mm × 0.5 mm. According to JB / T 4323.2-1999 "Test Methods for Aqueous Metal Cleaners", the steel sheet is polished and pretreated, and then the polished test piece is successively wiped clean with solvent gasoline, solvent gasoline, absolute ethanol, and hot absolute ethanol at a temperature of 50-60 °C using forceps to hold cotton balls, dried with hot air, and cooled in a desiccator for standby.

[0083] (2) Preparation of artificial oil stain

[0084] The artificial oil stain is prepared from N32 HL hydraulic oil (general machine tool industrial oil), industrial white vaseline, and barium petroleum sulfonate in a mass ratio of 2:1:1, and dissolved at about 120°C, stirred to make it evenly mixed.

[0085] (3) Determination of degreasing rate

[0086] The degreasing rate (gravimetric method) is tested according to the standard test method of JB / T4323.2 - 1999. The sample prepared above is diluted to a solution with a mass fraction of (3±0.1)%, and pure water is selected as the solvent to reduce the addition and adverse effects of impurity ions.

[0087] The polished and cleaned test pieces are respectively hung with hooks and weighed (0.1mg), and this weight is represented by P1. The weighed test pieces are immersed in the artificial oil stain preheated to the oil immersion temperature (70 - 80°C) for more than 5 minutes (N46 HL hydraulic oil is immersed and coated at room temperature). After the temperature of the test piece and the oil is the same, the test piece is taken out and drained for 20 minutes, and the oil drops accumulated at the bottom of the test piece are scraped off, and then weighed together with the original hook, and this weight is represented by P2. P2 - P1 is the oil stain immersion amount of the test piece.

[0088] The test piece after oil immersion and weighing is fixed on the pendulum washer with the original hook, so that the surface of the test piece is perpendicular to the swinging direction, and is respectively immersed in 3 pendulum washing tanks containing 500 mL of test solution at 65°C±2°C. Immediately record the time, soak statically for 3 minutes, swing and wash for 3 minutes, take out the test piece, and then swing and wash 10 times in 500 mL of distilled water at 65°C±2°C. Take out the test piece and immediately dry it in an oven at 70°C±2°C for 30 - 40 minutes. After taking it out and cooling to room temperature, weigh it, and this weight is represented by P3. P2 - P3 is the weight of the oil stain washed off.

[0089] The cleaning ability is represented by the degreasing rate P and calculated according to the following formula:

[0090]

[0091] (2) Determination of residual iron content and residual oil content

[0092] According to the YB / T4302 - 2012 standard, the residual oil content is determined by the gravimetric method and the residual iron content is determined by the spectrophotometer method.

[0093] (3) Determination of defoaming performance

[0094] Dilute the sample prepared above to a solution with a mass fraction of (3 ± 0.1)%, and use pure water as the solvent to reduce the addition and adverse effects of impurity ions. Pour the test solution into a stoppered graduated cylinder so that the liquid level is 70 mm from the lower end face of the stopper. Cover the stopper, preheat it at (30 ± 2) °C for 10 min, take it out and shake it up and down for 1 min, with a frequency of 100 - 110 times / min and a shaking distance of about 0.33 m. Take it out after standing for 10 min in a water bath or an electric oven at the same temperature, observe the disappearance of the foam, and record the height of the remaining foam.

[0095] The performance test results of Examples 1 - 4 and Comparative Examples 1 - 2 are shown in Table 3.

[0096] Table 3 Performance test results of Examples 1 - 4 and Comparative Examples 1 - 2

[0097] Group Degreasing rate / % <![CDATA[Residual iron content mg / m 2 > <![CDATA[Residual oil content mg / m 2 > Foam height / mm Example 1 88.9 5.6 4.1 4.3 Example 2 90.6 3.7 2.6 3.5 Example 3 87.1 4.9 3.3 3.2 Example 4 85.3 4.5 3.7 3.1 Comparative Example 1 78.7 6.2 8.2 3.7 Comparative Example 2 76.9 6.4 8.8 3.6

[0098] As can be seen from Tables 1 - 3 and the measurement results of Examples 1 - 4, the degreasing agents in Examples 1 - 4 all have good oil and dirt removal capabilities, with a high degreasing rate. The residual iron content and residual oil content both meet the national standards, and the height of the remaining foam ≤ 5 mm, meeting the national standards. This degreasing agent has the advantages of high efficiency and low foam, and does not contain environmentally controlled substances such as phosphorus-containing substances, will not cause phosphorus pollution to the environment, and is safe and environmentally friendly. By comparing Comparative Example 1, Comparative Example 2 with Example 2, it can be seen that sodium lignosulfonate and fatty alcohol polyoxyethylene polyoxypropylene ether have an obvious synergistic effect.

[0099] One or more technical solutions in the embodiments of the present invention at least further have the following technical effects or advantages:

[0100] The embodiments of the present invention do not contain environmentally controlled substances such as phosphorus-containing substances, will not cause phosphorus pollution to the environment, and are safe and environmentally friendly.

[0101] The corrosion inhibitor polyacrylamide is added in the embodiments of the present invention, so it has good corrosion inhibition.

[0102] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features claimed in the present application.

Claims

1. A low-foaming phosphorus-free compound degreaser. By mass fraction, the degreaser comprises: Sodium carbonate: 2% - 5%, sodium hydroxide: 7% - 12%, phosphorus-free builder: 1.5% - 10%, disodium ethylenediaminetetraacetate: 4% - 7%, sodium carboxymethyl cellulose: 4% - 7%, 4A zeolite: 1.5% - 3%, compound surfactant: 12% - 20%, solubilizer: 0.2% - 1.5%, polyacrylamide: 1% - 4%, polyether-modified silicone defoamer: 0.2% - 3.5%.

2. The degreaser according to claim 1, wherein The phosphorus-free builder is at least one of sodium metasilicate nonahydrate, sodium citrate, and sodium gluconate.

3. The degreasing agent according to claim 1, characterized in that, The compound surfactant is obtained by compounding sodium lignosulfonate and fatty alcohol polyoxyethylene polyoxypropylene ether.

4. The degreasing agent according to claim 3, characterized in that, The mass ratio of the sodium lignosulfonate to the fatty alcohol polyoxyethylene polyoxypropylene ether is (0.8 - 1.5):

1.

5. The degreasing agent according to claim 1, characterized in that, The solubilizer is at least one of sorbitan fatty acid ester and octyliminodipropionate.

6. A preparation method of the degreasing agent according to any one of claims 1 - 5, the method comprising: According to the mass fractions, mixing and stirring the phosphorus-free builder, the disodium ethylenediaminetetraacetate, the sodium carboxymethyl cellulose, and the 4A zeolite in water for the first time to obtain a first mixture; According to the mass fractions, mixing and stirring the first mixture, the compound surfactant, the solubilizer, the polyacrylamide, and the defoamer for the second time to obtain a second mixture; According to the mass fractions, mixing and stirring the second mixture, the sodium hydroxide, and the sodium carbonate in water for the third time to obtain a third mixture; After the temperature of the third mixture reaches room temperature, performing a fourth mixing and stirring to obtain the degreasing agent.

7. The method according to claim 6, wherein The time of the first mixing and stirring is 20 min - 40 min, and the rotation speed of the first mixing and stirring is 200 r / min - 550 r / min.

8. The method according to claim 6, characterized in that, The temperature of the second mixing and stirring is 50°C - 60°C, the time of the second mixing and stirring is 15 min - 40 min, and the rotation speed of the second mixing and stirring is 200 r / min - 500 r / min.

9. The method according to claim 6, wherein The temperature of the third mixing and stirring is 50°C - 70°C, the time of the third mixing and stirring is 30 min - 60 min, and the rotation speed of the third mixing and stirring is 150 r / min - 400 r / min.

10. The method according to claim 6, wherein The time of the fourth mixing and stirring is 20 min - 40 min, and the rotation speed of the fourth mixing and stirring is 150 r / min - 400 r / min.

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