Water-based cleaning solvent as well as preparation method and application thereof

Abstract

The invention provides a water-based cleaning solvent as well as a preparation method and application thereof, and belongs to the field of cleaning agents. The water-based cleaning solvent comprises the following chemical components: 60 to 80 parts of a solvent, 10 to 20 parts of a cosolvent, 2 to 3 parts of a surfactant, 2 to 5 parts of N, N-dimethylethanolamine and 1 to 2 parts of 2, 2 ', 2' '-trihydroxytriethylamine. The cleaning solvent disclosed by the invention is formed by compounding multiple organic solvents with higher boiling points and higher dissolving power, and additives such as the surfactant, the wetting agent and the penetrant are added, so that the cleaning solvent is safe to use, has higher solubility for water-based colored paints from different manufacturers, is zero in VOC emission, can dissolve and quickly remove the water-based colored paints on the surface to be cleaned, and has a good cleaning effect on the water-based colored paints. And the inner and outer surfaces of the rotary cup can be quickly and efficiently cleaned. Therefore, on the basis of realizing zero VOC content of the water-based cleaning solvent, the cleaning efficiency of the water-based colored paint is improved.

Description

Technical Field

[0001] The present application relates to the technical field of cleaning agents, and in particular to an aqueous cleaning solvent, a preparation method, and an application thereof. Background Art

[0002] Domestic car factories basically use water-based mid-coat-free paint + rotary cup spraying technology for body paint. During the spraying process, paint and paint mist will be deposited on the inner and outer walls of the rotary cup. At the same time, the paint needs to be changed during spraying. In order to ensure that there is no color bleeding and no external paint residue or paint falling on the car body surface during the spraying process, the rotary cup is usually cleaned after every 5 cars when spraying the same color on the inside and outside. It is cleaned every time the color is changed, and the inside and outside of the rotary cup are cleaned for each car. The rotary cup is manually cleaned and maintained every two hours.

[0003] Existing technology uses hydrophilic ether-based organic solvents and volatile alcohol-based organic solvents with a boiling point below 250°C as the main solvent, mixed with defoamers and surfactants and water. This technology has a high VOC content of up to 80%, resulting in poor cleaning performance. Manual cleaning and maintenance are required after 1.5 hours, otherwise there is a risk of color transfer and paint dripping, which affects workshop production cycles. The paint mist dissolving ability is particularly poor on the outside of the rotary cup. Therefore, achieving zero-VOC aqueous cleaning solvents while improving cleaning efficiency is an urgent technical challenge. Summary of the Invention

[0004] The present application provides an aqueous cleaning solvent and a preparation method and application thereof to solve the following technical problem: how to improve the cleaning efficiency of water-based paint on the basis of achieving zero VOC content in the aqueous cleaning solvent.

[0005] In a first aspect, the present application provides an aqueous cleaning solvent, which comprises the following chemical components, in parts by weight: 60 to 80 parts of solvent, 10 to 20 parts of cosolvent, 2 to 3 parts of surfactant, 2 to 5 parts of N,N-dimethylethanolamine, and 1 to 2 parts of 2,2',2"-trihydroxytriethylamine;

[0006] The solvent is an organic ether compound with a boiling point greater than 250°C, and the boiling point of the co-solvent is greater than 250°C.

[0007] Optionally, the solvent consists of tripropylene glycol butyl ether and diethylene glycol monohexyl ether.

[0008] Optionally, the mass ratio of the tripropylene glycol butyl ether to the diethylene glycol monohexyl ether is (4-5):(2-3).

[0009] Optionally, the cosolvent is sulfolane.

[0010] Optionally, the surfactant is 2,4,7,9-tetramethyl-5-decene-4,7-diol.

[0011] Optionally, the volatile organic compound content of the aqueous cleaning solvent is 0 g / L.

[0012] In a second aspect, the present application provides a method for preparing the aqueous cleaning solvent according to any one embodiment of the first aspect, the method comprising:

[0013] Obtaining the raw materials of the aqueous cleaning solvent;

[0014] Under stirring, the cosolvent, the surfactant, the N,N-dimethylethanolamine and the 2,2',2"-trihydroxytriethylamine are added to the solvent to obtain the aqueous cleaning solvent.

[0015] Optionally, the stirring speed is 100 rpm to 300 rpm, and the stirring time is 5 min to 15 min.

[0016] In a third aspect, the present application provides a use of the aqueous cleaning solvent described in any one embodiment of the first aspect, wherein the aqueous cleaning solvent is used to clean water-based paint after being diluted with water.

[0017] Optionally, the mass of the aqueous cleaning solvent is 3% to 5% of the mass of the water.

[0018] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0019] The embodiment of the present application provides an aqueous cleaning solvent, which includes the following chemical components in parts by weight: 60 to 80 parts of solvent, 10 to 20 parts of cosolvent, 2 to 3 parts of surfactant, 2 to 5 parts of N,N-dimethylethanolamine, and 1 to 2 parts of 2,2',2"-trihydroxytriethylamine; the solvent is an organic ether compound with a boiling point greater than 250°C, and the boiling point of the cosolvent is greater than 250°C. The chemical composition of the aqueous cleaning solvent is rationally designed, and the solvent selected is an organic ether compound with a boiling point greater than 250°C. These compounds not only have a high boiling point, ensuring zero VOC emissions, but also possess excellent solubility for resins, pigments, and other components in water-based paints. Surfactants and cosolvents are added. The surfactants have excellent wetting and defoaming properties, while the cosolvents enhance the solvent's solubility. The weak alkalinity and chelating properties of N,N-dimethylethanolamine and 2,2',2"-trihydroxytriethylamine (triethanolamine) disrupt the ester crosslinks in the paint film and its anchoring to the metal substrate, enabling rapid film stripping. Furthermore, the amine compounds promote the penetration of the solvent and cosolvent into the paint film, accelerating the dissolution process. The resulting aqueous cleaning solvent is safe to use, exhibits high solubility for water-based paints from various manufacturers, and produces zero VOC emissions. It dissolves and rapidly removes water-based paint from the surface being cleaned, achieving rapid and efficient cleaning of both the inner and outer surfaces of the rotary cup. This improves the cleaning efficiency of water-based paints while achieving zero VOC content in the aqueous cleaning solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 A schematic flow chart of a method for preparing an aqueous cleaning solvent provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] Various embodiments of the present application may be presented 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 understood as a hard limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numbers within the range. For example, the description of a range from 1 to 6 should be considered to have 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., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0025] In addition, in the description of the specification of this application, the terms "including", "comprising", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second" are merely 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. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this article, "at least one" refers to one or more, and "plurality" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple. "Parts" such as parts by weight and parts by mass represent the proportional relationship between the components. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional 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-to-one to the proportional numbers in the proportional 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.

[0026] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0027] The present application provides an aqueous cleaning solvent, which comprises the following chemical components, in parts by weight: 60 to 80 parts of solvent, 10 to 20 parts of cosolvent, 2 to 3 parts of surfactant, 2 to 5 parts of N,N-dimethylethanolamine, and 1 to 2 parts of 2,2',2"-trihydroxytriethylamine;

[0028] The solvent is an organic ether compound with a boiling point greater than 250°C, and the boiling point of the co-solvent is greater than 250°C.

[0029] In some embodiments, the solvent consists of tripropylene glycol butyl ether and diethylene glycol monohexyl ether.

[0030] In some embodiments, the mass ratio of the tripropylene glycol butyl ether to the diethylene glycol monohexyl ether is (4-5):(2-3).

[0031] In some embodiments, the cosolvent is sulfolane.

[0032] In some embodiments, the surfactant is 2,4,7,9-tetramethyl-5-decene-4,7-diol.

[0033] It should be noted that the chemical formula of N,N-dimethylethanolamine (DMEA) is C4H 11 NO, CAS number 108-01-0, contains both hydroxyl and amino groups in its molecule, making it both hydrophilic and alkaline, capable of reacting with acids to form salts. At the same time, it is weakly alkaline and has moderate pH adjustment capabilities, making it suitable for sensitive systems (such as water-based coatings).

[0034] 2,2',2"-Trihydroxytriethylamine (triethanolamine, TEA), chemical formula C6H 15 NO3 contains one nitrogen atom and three hydroxyethyl groups. It is weakly alkaline (pH about 8-9) and can react with acids to form salts. It can also form chelates with metal ions. It is a multifunctional organic compound. Its weak alkalinity, chelating properties and surface activity make it widely used in medicine, cosmetics, industry and other fields.

[0035] Tripropylene glycol butyl ether (TPNB), molecular formula C 13 H 28 O4, CAS number 55934-93-5, is low-odor, non-VOC, and has a high boiling point (above 250°C). It is highly soluble in a variety of polymer materials, including alkyd resins, epoxy resins, and acrylic resins, making it particularly suitable for water-based systems. It also meets green solvent standards and has low volatility, making it suitable for environmentally friendly coatings and cleaning agents.

[0036] Hexyl Carbitol, molecular formula: C 10 H 22 O3, with a boiling point of 259.1°C, is well-suited for high-temperature processes. It also has strong solubility for oils, resins, and dyes, and is partially miscible with water, making it commonly used in oil-based systems. Furthermore, it possesses both coupling and dispersing properties, improving the dispersion stability of pigments and fillers in the medium.

[0037] Sulfolane (chemical formula: C4H8O2S, CAS number: 126-33-0), also known as tetrahydrothiophene-1,1-dioxide, is a colorless, transparent liquid with unique aprotic polar solvent properties. It is widely used in the chemical, electronics, and energy industries. Its boiling point of 285°C (standard atmospheric pressure) makes it suitable for high-temperature processes. It is miscible with a variety of solvents, including water, acetone, and toluene, and has a significant solubility for aromatic hydrocarbons, polymers, and inorganic salts. It is chemically stable below 220°C. Furthermore, it has low volatility (low vapor pressure), meets green solvent standards, has low toxicity, and is non-corrosive to carbon steel.

[0038] 2,4,7,9-Tetramethyl-5-decyne-4,7-diol (also known as tetramethyldecyne diol, TMDD), molecular formula is C 14 H 26 O2, CAS No. 126-86-3, is a multifunctional surfactant. Its unique structure gives it wetting, defoaming and dispersing properties. It is widely used in coatings, inks and chemical synthesis.

[0039] The chemical composition of the aqueous cleaning solvent is rationally designed in the embodiments of the present application. Specifically, the functions of each component are as follows:

[0040] The solvent is composed of tripropylene glycol butyl ether (BTE), with a boiling point above 250°C, and diethylene glycol monohexyl ether (DGE), with a boiling point of 260°C. BTE has a strong solubility for paints and inks, making it suitable as a solvent and diluent for these materials, quickly softening the paint film's main structure. DGE effectively dissolves and disperses acrylic, polyurethane, and amino resins, as well as pigments and fillers, in primer-free paints. Its low surface tension and high polarity allow it to effectively penetrate the underlying coating layer, separating it from the substrate. This allows it to penetrate the paint-substrate interface, weakening adhesion and enabling layer-by-layer peeling. Exemplarily, the mass parts of the solvent can be 60 parts, 62 parts, 65 parts, 70 parts, 75 parts, 80 parts, etc., and the mass ratio of tripropylene glycol butyl ether and diethylene glycol monohexyl ether can be 4:2, 4:2.2, 4:2.4, 4:2.6, 4:2.8, 4:3, 5:2, 5:2.2, 5:2.4, 5:2.6, 5:2.8, 5:3, etc.

[0041] The cosolvent is sulfolane, which has a boiling point of 285°C and is an excellent aprotic polar solvent that is miscible with water. It binds to water molecules through hydrogen bonds, enhancing the dispersion of organic ethers in water and preventing phase separation. It also forms mixed micelles with surfactants, lowering the critical micelle concentration and increasing the solubility and emulsification properties of the surfactant, allowing it to emulsify the paint more quickly. For example, the mass fraction of the cosolvent can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, etc.

[0042] The surfactant is 2,4,7,9-tetramethyl-5-quinoline-4,7-diol, which can effectively improve the fluidity of the paint, reduce the surface tension of the paint, and promote the wetting performance of the cleaning solvent on the paint surface. At the same time, it also has a certain defoaming function to prevent the generation of foam during the cleaning process. In addition, its steric hindrance effect inhibits foam generation and avoids obstruction of cleaning agent penetration. Exemplarily, the mass parts of the surfactant can be 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, etc.

[0043] N,N-dimethylethanolamine is highly reactive and can react with certain chemical components in paint, causing them to break down and dislodge. It also quickly penetrates the surface and interior of the paint, accelerating the paint stripping process. For example, the weight percentage of N,N-dimethylethanolamine can be 2 parts, 3 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0044] The hydroxyl group in 2,2',2"-trihydroxytriethylamine can form hydrogen bonds with certain components in the paint film, thereby destroying the ester bond cross-linking structure of the paint film and dissolving certain components in the paint film. At the same time, the hydroxyl group of 2,2',2"-trihydroxytriethylamine can form hydrogen bonds with the surface oxides of the metal substrate (such as Fe 3+ , Al3+), forming a chelate complex, which weakens the anchoring effect of the paint film. This reduces the interaction between the paint film and the bell wall, making it easier to peel the paint from the bell wall. Triethanolamine can also increase the moisture content of the paint mist outside the bell, causing the paint mist to dry more slowly and reducing the adhesion of the paint to the bell. For example, the weight percentage of 2,2',2"-trihydroxytriethylamine can be 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, etc.

[0045] At the same time, the components of the aqueous cleaning solvent in the embodiment of the present application work together in multiple dimensions to significantly improve the cleaning efficiency of water-based paint while achieving zero VOC content:

[0046] (1) Solvent compounding synergy: tripropylene glycol butyl ether has strong solubility for polymer materials such as acrylic acid and epoxy resin, and can quickly soften the main structure of the paint film; diethylene glycol monohexyl ether, with its low surface tension and high polarity, penetrates into the paint film-substrate interface and destroys the adhesion. The two work together to achieve "from the surface to the inside" layer-by-layer dissolution, which improves the cleaning efficiency compared to a single solvent.

[0047] (2) Solvent bridging effect: Cyclopentane sulfone combines with water molecules through hydrogen bonds, enhancing the dispersion stability of organic ether solvents in the aqueous phase and avoiding phase separation; at the same time, it forms mixed micelles with surfactants, reducing the critical micelle concentration of surfactants and improving emulsification efficiency.

[0048] (3) Surfactant function integration: 2,4,7,9-tetramethyl-5-quinoline-4,7-diol has both wetting and defoaming properties. The alkyne structure reduces its dynamic surface tension to below 25 mN / m, accelerating the wetting of the paint film surface; the steric hindrance effect inhibits foam generation, preventing foam retention from affecting the penetration of cleaning agents.

[0049] (4) Synergistic film breaking by amine compounds: DMEA and TEA form an acid-base-chelating dual-mode action mechanism. DMEA destroys the ester bond cross-linking structure in the paint film through weak alkalinity, especially for polyurethane coatings, with a decomposition efficiency of 70%; the hydroxyl group of TEA forms a chelate (such as Fe-O-TEA) with the oxide on the surface of the metal substrate, weakening the anchoring effect of the paint film; the two work together to shorten the paint film stripping time.

[0050] (5) Volatility control: The boiling point of the components is greater than 250°C, of ​​which the vapor pressures of TPNB and diethylene glycol monohexyl ether are as low as 0.01 mmHg (25°C) and 0.03 mmHg, respectively, meeting the EPA's definition threshold for VOCs (boiling point greater than 250°C exemption).

[0051] (6) Green solvent synergy: Both sulfolane and organic ethers meet the OECD green solvent standards and maintain a liquid phase recovery rate of >95% in the high-temperature (80-100°C) cleaning process, achieving near-zero emissions.

[0052] In some embodiments, the aqueous cleaning solvent has a volatile organic compound content of 0 g / L.

[0053] Therefore, the cleaning solvent of the embodiment of the present application is compounded by a variety of organic solvents with higher boiling points and stronger dissolving power, and additives such as surfactants, wetting agents and penetrants are added. It is safe to use, has high solubility in water-based paints from different manufacturers, and has zero VOC emissions. It can dissolve and quickly remove the water-based paint on the surface to be cleaned, thereby achieving rapid and efficient cleaning of the inner and outer surfaces of the rotary cup.

[0054] Figure 1 A schematic flow chart of a method for preparing an aqueous cleaning solvent provided in an embodiment of the present application.

[0055] like Figure 1 As shown, the present application provides a method for preparing the aqueous cleaning solvent described in any one of the above embodiments, the method comprising:

[0056] S1, obtaining the raw materials of the aqueous cleaning solvent;

[0057] S2. Under stirring, adding the cosolvent, the surfactant, the N,N-dimethylethanolamine and the 2,2',2"-trihydroxytriethylamine to the solvent to obtain the aqueous cleaning solvent.

[0058] The order of adding cosolvent → surfactant → amine compounds in step S2 conforms to the principle of solvation energy gradient: adding sulfolane first can preferentially form a hydrogen bond network with water, providing a dispersion medium for the subsequent organic ether; adding amines (DMEA and TEA) later can avoid premature hydrolysis of the surfactant caused by the alkaline environment.

[0059] In some embodiments, the stirring speed is 100 rpm to 300 rpm, and the stirring time is 5 min to 15 min.

[0060] The stirring speed is limited to 100 rpm to 300 rpm, and the stirring time is 5 min to 15 min. This can achieve sufficient mixing of the solvent, cosolvent, and surfactant, and avoid phase separation caused by excessive local concentration. For example, the stirring speed can be 100 rpm, 120 rpm, 150 rpm, 200 rpm, 250 rpm, 280 rpm, 300 rpm, etc., and the stirring time can be 5 min, 7 min, 9 min, 11 min, 13 min, 15 min, etc.

[0061] The product prepared by the method for preparing the aqueous cleaning solvent is the above-mentioned aqueous cleaning solvent. The chemical composition of the aqueous cleaning solvent prepared by the method for preparing the aqueous cleaning solvent can refer to the above-mentioned embodiment. Since the method for preparing the aqueous cleaning solvent adopts part or all of the technical solutions of the aqueous cleaning solvent embodiment, it has at least all the beneficial effects brought by the technical solutions of the aqueous cleaning solvent embodiment, which will not be repeated here.

[0062] Based on a general inventive concept, the present application provides a use of an aqueous cleaning solvent as described in any one of the above embodiments, wherein the aqueous cleaning solvent is used to clean water-based paint after being diluted with water.

[0063] In some embodiments, the mass of the aqueous cleaning solvent is 3% to 5% of the mass of the water.

[0064] This embodiment of the application utilizes a solvent with a boiling point above 250°C as the main solvent, along with a surfactant, a cosolvent (which must be heated and melted in winter), and a penetrant, and then stirred uniformly. This significantly improves the swelling and dissolution of paint mist on the outside of the rotary cup, while achieving zero VOC emissions.

[0065] Furthermore, the aqueous cleaning solvent is compatible with all midcoat-free material systems from suppliers (PPG, BASF, AXALTA, NIPPONT, and Kansai), requires only a low dosage (3-5% by weight), has zero VOC content, and can maintain a production pace of manual cleaning every 2-2.5 hours (approximately 80-90 painted vehicles).

[0066] In summary, the aqueous cleaning solvent, preparation method, and application provided in the embodiments of the present application have the following advantages:

[0067] (1) High-efficiency cleaning performance: Through a rationally designed combination of chemical components, including high-boiling-point solvents (tripropylene glycol butyl ether and diethylene glycol monohexyl ether), cosolvents (cyclopentane sulfone), surfactants (2,4,7,9-tetramethyl-5-decyne-4,7-diol) and amine compounds (N,N-dimethylethanolamine and 2,2',2"-trihydroxytriethylamine), rapid and efficient cleaning of water-based paint is achieved. The various components significantly improve the cleaning efficiency and shorten the paint film stripping time through multi-dimensional synergistic effects.

[0068] (2) Zero VOC emissions: The boiling points of all organic components are above 250°C, meeting the EPA's VOC definition threshold, achieving zero VOC emissions and complying with environmental protection requirements. During the high-temperature cleaning process, both the solvent and co-solvent can maintain a high liquid phase recovery rate, achieving near-zero emissions.

[0069] (3) Wide applicability: The aqueous cleaning solvent is suitable for water-based paint material systems from a variety of suppliers, showing good compatibility and versatility. It can meet the needs of long-term continuous production and ensure that the production rhythm is not affected.

[0070] (4) Simple preparation process: The preparation method is simple and clear. The required aqueous cleaning solvent can be prepared by stirring the raw materials to mix them evenly. The preparation process does not require complicated equipment or operations, which reduces production costs.

[0071] (5) Safety and environmental protection: The selected raw materials all meet environmental protection standards and are harmless to the human body and the environment. No harmful gases or substances are generated during use, ensuring the safety of operators.

[0072] (6) Significant economic benefits: Low dosage (3-5% by weight) reduces production costs. High cleaning efficiency reduces the number and time of cleaning and improves production efficiency.

[0073] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods in the following examples where specific conditions are not specified are generally measured according to industry standards. If there are no corresponding industry standards, then the methods are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0074] Example 1

[0075] This embodiment provides an aqueous cleaning solvent, which includes the following chemical components, in parts by weight: 48 parts of triphenyl glycol butyl ether, 25 parts of diethylene glycol monohexyl ether, 18 parts of cyclopentane sulfone, 3 parts of 2,4,7,9-tetramethyl-5-quinoline-4,7-diol, 4 parts of N,N-dimethylethanolamine, and 2 parts of 2,2',2"-trihydroxytriethylamine.

[0076] Based on the above aqueous cleaning solvent, the present application also provides a method for preparing an aqueous cleaning solvent, which may specifically include the following steps:

[0077] S11, obtaining the raw materials of the aqueous cleaning solvent;

[0078] S21. Triphenyl glycol butyl ether and diethylene glycol monohexyl ether are mixed to obtain a mixed solvent. Under stirring, cyclopentane sulfone, 2,4,7,9-tetramethyl-5-quinoline-4,7-diol, N,N-dimethylethanolamine, and 2,2',2"-trihydroxytriethylamine are added to the mixed solvent to obtain the aqueous cleaning solvent, wherein the stirring speed is 200 rpm and the stirring time is 10 min.

[0079] Comparative Example 1

[0080] This comparative example is modified as follows based on Example 1:

[0081] This embodiment provides an aqueous cleaning solvent, which includes the following chemical components, in parts by weight: 58 parts of triphenyl glycol butyl ether, 15 parts of diethylene glycol monohexyl ether, 18 parts of cyclopentane sulfone, 3 parts of 2,4,7,9-tetramethyl-5-quinoline-4,7-diol, 4 parts of N,N-dimethylethanolamine, and 2 parts of 2,2',2"-trihydroxytriethylamine.

[0082] Comparative Example 2

[0083] This comparative example is modified as follows based on Example 1:

[0084] This embodiment provides an aqueous cleaning solvent, which includes the following chemical components in parts by weight: 50 parts of triphenyl glycol butyl ether, 25 parts of diethylene glycol monohexyl ether, 18 parts of cyclopentane sulfone, 3 parts of 2,4,7,9-tetramethyl-5-quinone-4,7-diol, and 4 parts of N,N-dimethylethanolamine.

[0085] Comparative Example 3

[0086] This comparative example is modified as follows based on Example 1:

[0087] This embodiment provides an aqueous cleaning solvent, which includes the following chemical components, in parts by weight: 52 parts of triphenyl glycol butyl ether, 25 parts of diethylene glycol monohexyl ether, 18 parts of cyclopentane sulfone, 3 parts of 2,4,7,9-tetramethyl-5-quinoline-4,7-diol, and 2 parts of 2,2',2"-trihydroxytriethylamine.

[0088] The aqueous cleaning solvent obtained in Example 1 and Comparative Examples 1 to 3 was mixed with deionized water for dilution to obtain a cleaning agent that can be directly used to clean water-based paint. The dilution ratio is 3%, that is, the mass of the aqueous cleaning solvent is 3% of the mass of deionized water. The cleaning agents obtained in Example 1 and Comparative Examples 1 to 3 were tested for cleaning performance. The results are shown in Table 1. The specific testing method is as follows:

[0089] The paint is applied to a smooth, clean glass plate. A film applicator is used to control the wet film thickness, and an acid burette is used to control the dripping rate of the cleaning solvent. The cleaning effect of the cleaning solvent droplets is observed, and the number of droplets and the area cleaned are counted. By counting the number of droplets and the corresponding cleaned area, the cleaning coverage per unit volume of solvent (e.g., the number of square centimeters cleaned per drop of solvent) is calculated, thereby quantifying the cleaning efficiency. This data can be directly used to compare the performance of different solvents. Therefore, the cleaning effect of a cleaning agent can be determined based on the number of droplets of cleaning agent on the same cleaning area.

[0090] Table 1 Cleaning performance of the cleaning agents of Example 1 and Comparative Examples 1 to 3

[0091] Serial number Paint unit Required value Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 1 Pearlescent Black drop ≤8 5 8 7 10 2 White drop ≤8 6 9 8 9 3 Metallic Gray drop ≤8 4 7 9 8 4 Gentleman Ink Blue drop ≤8 5 6 8 9 5 metallic silver drop ≤8 4 6 7 9 6 metallic gold drop ≤8 6 9 8 10 7 Plain Gray B1 drop ≤8 5 7 9 11 8 White B1 drop ≤8 6 7 8 10 9 Pearlescent Green drop ≤8 6 9 8 11 10 Dark Gray B0 drop ≤8 4 6 9 12 11 Light gray B0 drop ≤8 5 7 9 10 12 Plain Gray B1 drop ≤8 6 7 10 12 13 Pearlescent Gray B2 drop ≤8 4 7 9 9

[0092] As shown in Table 1, the cleaning agent of Example 1 can meet the cleaning requirements of different paint types. In Comparative Example 1, the solvents triphenyl glycol butyl ether and diethylene glycol monohexyl ether do not meet the specified range, resulting in failure to meet the cleaning requirements of some paint types. Comparative Example 2 does not include 2,2',2"-trihydroxytriethylamine. The hydroxyl group in 2,2',2"-trihydroxytriethylamine can form hydrogen bonds with certain components in the paint film, thereby destroying the paint film structure and dissolving certain components. At the same time, the strong polarity of triethanolamine can weaken the interaction between the paint film and the wall of the bell, making it easier to peel the paint from the bell wall. Comparative Example 3 does not include N,N-dimethylethanolamine. N,N-dimethylethanolamine has strong chemical reactivity and can react with certain chemical components in the paint, causing them to decompose and fall off. N,N-dimethylethanolamine also quickly penetrates the surface and interior of the paint, accelerating the paint stripping process. Therefore, the cleaning agents of Comparative Examples 2 and 3 have poor cleaning performance.

[0093] In addition, one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0094] In the examples of this application, the aqueous cleaning solvent is compatible with all midcoat-free material systems from suppliers (PPG, BASF, AXALTA, NIPPONT, and Kansai), requires a low dosage (3-5% by weight), has zero VOC content, and can maintain a production cycle of manual cleaning every 2-2.5 hours (approximately 80-90 painted vehicles).

[0095] In the embodiment of the present application, a compound of multiple organic solvents with higher boiling points and stronger dissolving power is used, and additives such as surfactants, wetting agents and penetrants are added. It is safe to use, has high solubility for water-based paints from different manufacturers, and has zero VOC emissions. It can dissolve and quickly remove the water-based paint on the surface to be cleaned, thereby achieving rapid and efficient cleaning of the inner and outer surfaces of the rotary cup.

[0096] In the embodiments of the present application, the emission of volatile organic solvents during the use of aqueous solvents is reduced, VOC is reduced to zero, the cleaning ability of the product is improved to meet the requirements of different types of paints, the manual maintenance time is extended to 2 to 2.5 hours, and at the same time, it is ensured that the selected materials do not cause harm to the human body.

[0097] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. An aqueous cleaning solvent, comprising the following chemical components, in parts by weight: 60 to 80 parts of a solvent, 10 to 20 parts of a cosolvent, 2 to 3 parts of a surfactant, 2 to 5 parts of N,N-dimethylethanolamine, and 1 to 2 parts of 2,2',2"-trihydroxytriethylamine; The solvent is an organic ether compound with a boiling point greater than 250°C, and the boiling point of the co-solvent is greater than 250°C.

2. The aqueous cleaning solvent according to claim 1, characterized in that The solvent consists of tripropylene glycol butyl ether and diethylene glycol monohexyl ether.

3. The aqueous cleaning solvent according to claim 2, characterized in that The mass ratio of the tripropylene glycol butyl ether to the diethylene glycol monohexyl ether is (4-5):(2-3).

4. The aqueous cleaning solvent according to claim 1, characterized in that The cosolvent is sulfolane.

5. The aqueous cleaning solvent according to claim 1, characterized in that The surfactant is 2,4,7,9-tetramethyl-5-decene-4,7-diol.

6. The aqueous cleaning solvent according to claim 1, characterized in that The volatile organic compound content of the aqueous cleaning solvent is 0 g / L.

7. A method for preparing the aqueous cleaning solvent according to any one of claims 1 to 6, comprising: Obtaining the raw materials of the aqueous cleaning solvent; Under stirring, the cosolvent, the surfactant, the N,N-dimethylethanolamine and the 2,2',2"-trihydroxytriethylamine are added to the solvent to obtain the aqueous cleaning solvent.

8. The aqueous cleaning solvent according to claim 7, characterized in that The stirring speed is 100 rpm to 300 rpm, and the stirring time is 5 min to 15 min.

9. Use of the aqueous cleaning solvent according to any one of claims 1 to 6, wherein the aqueous cleaning solvent is used to clean water-based paint after being diluted with water.

10. The use according to claim 9, characterized in that The mass of the aqueous cleaning solvent is 3% to 5% of the mass of the water.

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